# Tissue-Specific Trace Element Distribution in Wild Muskoxen (Ovibos moschatus) from Dovrefjell, Norway

Rachel Winter, Floris van Beest, Niels Martin Schmidt, Sophia Hansson

► To cite this version:

Rachel Winter, Floris van Beest, Niels Martin Schmidt, Sophia Hansson. Tissue-Specific Trace Element Distribution in Wild Muskoxen (Ovibos moschatus) from Dovrefjell, Norway. Biological Trace Element Research, In press, 10.1007/s12011-025-04940-3. hal-05512767

HAL Id: hal-05512767

https://hal.science/hal-05512767v1

Submitted on 16 Feb 2026

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons CC BY 4.0 - Attribution - International License
Tissue-specific trace element distribution in wild muskoxen (*Ovibos moschatus*)
from Dovrefjell, Norway

Rachel M. Winter¹, Floris M. van Beest², Niels Martin Schmidt², and Sophia V. Hansson*¹,²

¹ Centre de Recherche sur la Biodiversité et l'Environnement, Université de Toulouse, CNRS UMR 5300, IRD, Toulouse INP, Avenue de l'Agrobiopole, 31326 Toulouse, France.

² Department of Ecoscience and Arctic Research Centre, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark

*corresponding author (sophia.hansson@toulouse-inp.fr)

ORCID:

Rachel M. Winter: 0000-0002-9970-1450

Floris M. van Beest: 0000-0002-5701-4927

Niels Martin Schmidt: 0000-0002-4166-6218

Sophia V. Hansson: 0000-0001-5874-0720

Acknowledgements

The authors wish to thank Miljødirektoratet, Norway, and especially Tord Bretten, for providing samples. The authors also wish to thank Hugo Gilbert, Jules Giraud and Laetitia Leroy (all at CRBE, Toulouse, France) for assistance with sample preparations and sample digestions in the clean room, and Camille Duquenoy and Aurélie Marquet (both at the ICP-MS platform at the Observatoire Midi-Pyrenees, Toulouse, France) for assistance with the ICP-MS analysis. Financial support was provided by the French National Research Agency (ANR) Young Researcher (JCJC) Grant awarded to SVH (ANR-21-CE34-0001 ATCAF-project).
30 Abstract

31

32 Trace element analysis of animal tissues has proven to be an effective tool for monitoring biotic health but such
33 methods often rely on invasive sampling. Further, the within body distribution of trace elements—the ionome—
34 within many species remains poorly understood. Using samples from muskoxen (Ovibos moschatus; n=14)
35 culled in Dovrefjell, Norway, we analyzed essential (Cu, Zn, Se, Mo) and non-essential (As, Cd, Ba, Pb) trace
36 element concentrations across eight tissues to map their internal distribution. We quantified concentrations via
37 TQ-ICP-MS and used multivariate analyses (PCA, PERMANOVA) and correlation tests to assess whether wool
38 can reliably reflect internal trace element concentrations, thus potentially serve as a non-invasive biomonitoring
tool. While the selected elements were detectable across all tissues, each element showed distinct distribution
39 patterns with low correlations between tissues. Generally, feces effectively eliminated most non-essential
40 elements (As, Ba, Pb), while Cd accumulated in kidneys. Essential element patterns were more variable and
41 inconsistent across individuals, likely influenced by physiological and demographic factors (age, sex, pregnancy
42 status). Element concentrations in wool showed weak, but not statistically significant, correlations with those in
43 internal tissues. Our findings – albeit based on a small sample-set – thus suggest that while wool may capture
44 certain element profiles, it does not consistently mirror internal tissue concentrations. This highlights the
45 continued need for multi-tissue approaches in ionomic profiling and emphasizes the importance of considering
46 geographical-, population- and individual-level variability in trace element studies conducted in a wildlife health
47 context. Further research is thus needed to fully validate wool as a reliable, standalone, non-invasive monitoring
48 tool for wildlife health.
49

50

51

52

53

54

55

56

57

58

59
60

**Keywords:** Ionomics, wildlife health, biomonitoring, ungulates, qiviut, Scandinavia
61 **Introduction**

62

63 Arctic and sub-arctic ecosystems are among the most rapidly affected by climate change [1-2] and as such the
64 abundance and distribution of fauna and flora in these regions are changing [3-4]. During the last rapidly
65 warming period in the late Pleistocene many megafauna were decimated by climatic changes [5], with
66 muskoxen (Ovibos moschatus) being one of the few survivors [6]. Once with a holarctic distribution, their
67 present-day native range has been drastically reduced to two endemic populations in the Canadian Arctic and
68 Greenland and introduced populations in Alaska and Russia [7]. Due to their large biomass, their trampling,
69 grazing and defecation activities, this iconic species provides important functions in the tundra ecosystem [8-9].
70 Their foraging and movement patterns are also considered to help mitigate the effects of climate change in these
71 sensitive ecosystems, such as shrubification [10-11] and greenhouse gas balance [12]. To this end, monitoring
72 the health and population status of muskoxen, and other Arctic fauna, is crucial to protecting the longevity of
73 both the animals themselves, as well as the ecosystems in which they reside.

74

75 Traditionally, research into animal health has relied on physiological observations such as body condition
76 scoring or serology analysis [13-14], yet recent work on trace element analysis of various tissues – i.e. the field
77 of ionomics [15] – has proven to be a promising tool for monitoring wildlife health [16-20]. To date, much of
78 the research in animal ionomics has been focused on terrestrial game animals and to assess whether regularly
79 consumed tissues (e.g. muscle, liver, and kidney) are low enough in contaminant concentrations (e.g. heavy
80 metals) for human consumption [e.g. 21-22]. However, there is also an increased interest in exploring
81 applications of ionomics for biomonitoring the health status of wildlife on both the individual and population
82 level [16-20, 23-27].

83

84 A key challenge to obtaining trace element data from animals, however, is that traditional methods of sampling
85 often focuses on internal tissues which require invasive methods and/or carcasses of hunted animals, both of
86 which are impractical for remote, endangered, or declining populations [28]. Trace element concentrations in
87 hair/wool may therefore be a promising and viable option for biomonitoring of mammals as it can be harvested
88 non-invasively, while also being metabolically inactive and stable [29-32]. Additionally, hair/wool may also
89 provide information on a longer temporal scale than e.g. blood or feces as it represents the entire time period
90 over which the hair has grown (often months to years) [33-34]. In the case of muskoxen, these animals possess
two different types of fur; long and thick guard hairs that grows continuously year-round and persists for
multiple years, as well as a woolen undercoat called “qiviut”, which grows from spring to autumn
(approximately April to November) and is then shed in a synchronized annual molt in the following late
spring/early summer. Once the wool is fully formed, it no longer interacts with the systemic mineral
metabolism, meaning that its chemical composition and the mineral profiles contained in the wool reflects the
physiological conditions during the preceding growth season [35-36] and can therefore – theoretically – be used
as an monitoring tool of individual mineral profile from which potential health status can be inferred. For
example, trace element concentrations measured in opportunistically collected shed wool from the wild
population in Zackenberg, Greenland, demonstrated a link between levels of copper (Cu), selenium (Se), and
molybdenum (Mo) with annual calf recruitment rates [16]. Similar results were found for multiple muskox
populations across the Arctic region [20], providing proof of concept that trace element concentrations in wool
may indeed be linked to wildlife health. This has also been seen in other arctic ungulates, i.e. trace element
analysis of hair samples from an endangered caribou population in Canada found that concentrations of sodium
(Na) and zinc (Zn) was related to probability of survival [18]. Winter et al. [17] also showed a link between low
selenium (Se) concentrations in hair with the occurrence of hoof disease in elk in the U.S. Pacific Northwest.
Combined, these works provide important baseline knowledge on the link between trace element concentrations
in hair/wool and population health for ungulates in general and for muskoxen in particular. However, questions
still remain regarding the distribution of trace elements throughout the muskoxen body and how the
concentrations found in wool compares to those of the internal tissues traditionally used (e.g. blood or liver) to
assess individual-health. Before hair/wool can be firmly considered a reliable tool for monitoring muskox
health, this gap in knowledge needs to be addressed.

112

To assess if wool can be used as a stand-alone non-invasive biomonitoring tool of health in muskoxen, and by
using eight different tissues from a muskox population in Dovrefjell, Norway, we aimed to map out the muskox
ionome and explore how the trace element concentrations in wool compare to a range of bodily tissues (i.e.
blood, liver, kidney, spleen and muscle) and samples (i.e. hoof clippings and feces). We focused on four
essential (Cu, Zn, Se and Mo) and four non-essential (arsenic (As), cadmium (Cd), barium (Ba) and lead (Pb))
trace elements as these have all been previously linked to muskox population dynamics [16, 20]. More
specifically, we ask 1) How are key essential and non-essential elements distributed throughout the body of
muskox? and 2) Do trace element concentrations in wool correlate with those in internal tissues, thereby
supporting its use as a stand-alone non-invasive biomonitoring tool in muskoxen? Answering these questions will be an important step towards validating wool as a stand-alone non-invasive biomonitoring tool for population health in wild muskoxen.

## Materials and Methods

### Study site and Dovrefjell muskox population

About 90% of the global muskoxen reside in the Canadian Arctic, Greenland, Alaska, and Russia [7] with two smaller populations, representing 0.15% of the global population, in Scandinavia. One of these is an introduced population of ca. 200 animals that resides in the Dovrefjell region of Norway [37]. The defined distribution range of the muskox in Dovrefjell is ~340 km² located on a mountain plateau of tundra alpine, and is divided between Oppdal, Dovre, and Lesja municipalities [37]. This core area is bordered by Snøhetta mountain on the western side and a highway and railroad on the eastern border, the latter of which causes a number of muskoxen fatalities each year. The underlying bedrock consists of granite, gneiss and metamorphosed sandstone, and the area is dominated by tundra vegetation that ranges from barren rock to lichen- and grass heath-communities as well as snow-bed vegetation [38-39]. Muskoxen in Dovrefjell utilize a range of these alpine vegetation types, and are reported to feed predominantly on nutrient-rich graminoid and forb meadows during the growing season, shifting to dwarf-shrub and lichen heaths in winter when forage access is limited [40]. Although variation in local flora between continents exist, this information also aligns with dietary information reported for muskoxen in Alaska, Russia, Canada and Greenland [41-45]. Compared to muskox populations residing in the Arctic, the Dovre population is subjected to both wetter and warmer climate, especially during the summer months, with mean temperatures of -8.8 °C in the winter and 9.8 °C in the summer [46-47]. Given these temperatures, the muskoxen are likely living outside of their thermal neutral zone [48], which, in turn, may affect their general condition and lead to an increased risk of disease outbreaks [49].

Occasional outbreaks of *Pasteurella* spp., *Mycoplasma* spp., and parapox virus have indeed been reported in the Dovrefjell population and are believed to be the joint by-product of spill over from other ungulates, as well as being attributable to a warmer, more humid climate in recent years [46-47, 50]. The risk of disease outbreak, in combination with increased instances of muskox individuals wandering outside of their core area due to a higher
population density, has contributed to the management goal of regulating population size to ~200 animals. As part of the local muskox population management, under the jurisdiction of Miljødirektoratet (the Norwegian Environment Agency), the population is therefore culled annually [37]. From this culling program, we were able to obtain samples from 14 animals (7 adults 3 sub-adults, 2 yearlings and 2 calves) culled in March 2022 (n=10) and in March 2023 (n=4). For each animal, sex, age category, and pregnancy status were recorded and are provided in the supplementary materials (Table S1). Most of the samples were obtained from females (n=12 ♀ and n=2 ♂) with 10 of those 12 females being pregnant at the time of culling. No animals were culled for the purpose of this study.

## Sample collection and processing

Following culling, eight different tissues and sample matrices (hereafter collectively referred to as tissues) were obtained from each carcass. Blood samples (~6 mL) were taken directly in the field from cut blood vessels in the throat and collected in 6 mL blood collection tubes (purple cap Vacuette® Tube 6 mL K2E K2EDTA). After transport back to the abattoir, samples of liver (13-26 g), kidney (11-22 g), spleen (13-83 g), muscle (10-38 g), and feces (14-96 g) were collected from each individual within 2-6 hours postmortem and transferred into pre-labelled zip lock bags. For liver, kidney and spleen, the entire organs were harvested after which a sub-sample was collected, i.e. the case of the kidney, although only a subset of the organ was collected, the final sample encompassed parts of both the renal cortex and the renal medulla. In addition, from each animal, samples of wool (13-41g) were collected by manually pulling it from the upper right rump and put into pre-labelled paper bags which were then placed in a zip lock bag, and samples of hoof clippings (6-71 g) were collected from the front right hoof and transferred to pre-labelled zip lock bags. All samples were handled with double powder-free nitrile gloves and regularly cleaned stainless steel instruments and stored in dark and frozen (-20°C) conditions until (and during the) transport to Toulouse, France, for further processing.

Prior to chemical mineralization, the outer-most part of each sample was removed using a clean stainless-steel scalpel, after which the frozen liver, kidney, spleen, and muscle samples (without visceral membranes) were lyophilized for 24-48hr at -44°C and 0.05 mbar using a Christ Alpha 1-2 freeze drier. All samples were weighed before and after freeze-drying to determine moisture content (see Table S2 for details). After freeze-drying, liver, kidney, muscle, and spleen samples were ground into a powder using a laboratory mill Retsch® Mixer MILL MM 400 at 30 Hz for 60 seconds and then transferred into 15 mL Falcon tubes. Hoof clippings were
washed with Milli-Q water (mQ H₂O; Ω = 18.2) to remove visible surface impurities and were then cut with
clean garden scissors into small pieces. Stainless steel tweezers, cleaned with mQ H₂O and 96% ethanol, were
used to remove any visual debris, and to separate the wool from guard hairs. Wool samples and hoof pieces
were washed in 96% ethanol and rinsed with mQ H₂O (procedure repeated twice) and then dried at 35°C in an
oven for 12 hours prior to digestion.

Chemical mineralization and trace element analysis

All sample digestions and dilutions took place in a clean room (class 10000, ISO 7) environment, utilizing acid cleaned (2% HNO₃ followed by rinsing with mQ H₂O) labware, at the Clean Room platform of CRBE-INP, Toulouse, France.

To prepare the blood samples for trace element analyses, we used an adaption of the protocol presented in Brumbaugh et al. [51] (2005), i.e. ~1.5 mL of thawed whole blood was added to 50 mL pre-cleaned (2% HNO₃) digitubes. Next, 2 mL of pure HNO₃ (67-69%; Optima™ Grade, Fisher) was added to the digitube and left under a fume hood uncapped for 1 hour, after which the caps were added back on, and the digitubes placed on a hotplate at 90°C for 45 minutes. After 15 minutes of cooling, 0.4 mL H₂O₂ (30-32%; Optima™ Grade, Fisher) was added to each digitube, caps placed back on, and digitubes were put back onto the hotplate at 90°C for an additional 45 minutes. Following another 15 minutes of cooling, the now digested mother solution was transferred to a clean 15 mL Falcon tube. Milli-Q H₂O was added to the digested solution to reach a final total volume of 14 mL. Prior to ICP-MS analysis, the samples were diluted by transferring 2 mL of the mother solution to a clean 15 mL Falcon tube, to which 8 mL of mQ H₂O was added.

For preparations of each of the tissues for elemental analysis, ca. 150 mg of the dried and ground liver, kidney, spleen, muscle, wool, hoof, and feces were added to digitubes (SCP Sciences 010-500-263) with 3 mL of ultrapure nitric acid (HNO₃; 67–69%, Optima™ Grade, Fisher) closed with airtight caps and digested overnight at 90°C. Once the samples had reacclimated to room temperature, they were subjected to two dilutions. The first dilution, to create a mother solution, was achieved by transferring the digest to a 15 mL Falcon tube and diluting it with mQ H₂O (3 mL digest: 11 mL mQ H₂O) for a total volume of 14 mL which was stored at ~4°C in dark conditions. For the second dilution, 1.5 mL of the mother solution was diluted to a total volume of 10 mL with mQ H₂O. All samples were stored in dark and cool (4°C) conditions between steps and until further analysis.
211

212

Digested tissues were analyzed for trace elements, i.e. Cu, Zn, As, Se, Mo, Cd, Ba, and Pb, with a Thermo Scientific® iCap TQ-ICP-MS at the ICP-MS platform of the Observatoire Midi-Pyrénées, Toulouse, France. For quality control and analytical assurance, blanks, replicates, and certified reference materials (i.e. ERM-DB001, IAEA-336, ClinCheck whole blood Level I, DOLT-5, DORM-4, IAEA-A-13, NIST 1515) were included with every ten samples alongside each step of the mineralization in the clean room (Table S3). Method detection limit for each element was set at three times the standard deviation of the procedural blanks. Procedural blanks were verified to be at least an order of magnitude lower than concentrations in real samples.

213

214

215

216

217

218

219

220

## Statistical analyses

221

To visualize the distribution of trace elements in different muskox tissues, windrose diagrams were created to show the relative trace element concentration in each tissue.

222

223

224

Data of elemental concentrations within tissues were not normally distributed. To assess differences in elemental composition among tissue types, we first performed a principal component analysis (PCA) on log-transformed, centred, and standardized concentration data. To statistically evaluate whether tissues occupied distinct space in the PCA, we used permutational multivariate analysis of variance (PERMANOVA) based on Euclidean distances with 999 permutations. To identify which tissue pairs differed significantly, we conducted post hoc pairwise PERMANOVA tests with Bonferroni correction for multiple comparisons (i.e. $p \le 0.028$ for significant differences between tissues). Besides the PCA analyses, we used non-parametric Spearman's correlations of the trace element concentrations between and within tissues to determine how comparable different tissues are to each other. All analyses were conducted using R (version 4.2.3; [52]).

225

226

227

228

229

230

231

232

233

234

235

## Results

236

237

The relative distribution of trace elements by tissue is provided in Figure 1 and Figure 2, and ranges (min – max) and median for each element in each tissue is presented in Table 1. The absolute concentrations for each individual and tissue are provided in Table S1.

238

239

240
241 *Essential and non-essential trace elements*

242 For the essential elements, copper was the most variable element across tissues with overall concentrations
243 ranging from 0.37 to 101.3 mg kg⁻¹ w.w. in the order liver > wool > feces > kidney > muscle > hoof > blood >
244 spleen. Zinc levels ranged from 1.57 to 205.4 mg kg⁻¹ w.w. and were greatest in wool > hoof > muscle > feces >
245 spleen > kidney > liver > blood. Selenium concentrations ranged from 0.03 to 2.10 mg kg⁻¹ w.w. and were
246 highest in kidney > spleen > hoof > liver > blood > wool > muscle > feces. Molybdenum concentrations ranged
247 from <0.001 to 0.891 mg kg⁻¹ w.w. and were most abundant in liver > kidney > feces > spleen > hoof > muscle
248 > wool > blood. As for the non-essential elements, arsenic concentrations ranged from 0.001 to 0.126 mg kg⁻¹
249 w.w. and were highest in feces > wool > hoof > muscle > liver > kidney > spleen > blood. Cadmium
250 concentrations ranged from <0.001 to 13.730 mg kg⁻¹ w.w. and was most concentrated in kidney > liver > feces
251 > spleen > muscle > wool > hoof > blood. Barium concentrations ranged from 0.03 to 130.0 mg kg⁻¹ w.w. and
252 were highest in feces > wool > spleen > kidney > hoof > liver > blood > muscle. Finally, lead concentrations
253 ranged from <0.001 to 2.86 mg kg⁻¹ w.w. and were highest in feces > liver > spleen > hoof > wool > kidney >
254 blood > muscle.

255

256 *Statistical analyses*

257 The results of the PCA assessing the comparability of trace element compositions between tissues are shown in
258 Figure 3. The first two principal components (PC1 and PC2), both with eigenvalues >1, accounted for 69.78%
259 of the total variance in the dataset, with PC1 explaining 47.31% and mainly driven by Pb and Mo, and PC2
260 explaining 22.47% mainly driven by Se. Despite minor overlap in multivariate space between elemental profiles
261 measured in wool and hoof, as well as between liver and kidney (Figure 3), results of the paired PERMANOVA
262 revealed statistical differences in the elemental profiles between all tissue pairs (p<0.001).

263

264 Spearman's correlation tests trace elements concentrations between paired tissues resulted in 224 combinations
265 with ca. 10% (n=22) of these being significant (p≤0.05) (Table S4). Notably however, is that wool only showed
266 two instances where the trace element concentrations were correlated with other tissues, i.e. for Se (r<sub>s</sub> = 0.73, p =
267 0.004) and Zn (r<sub>s</sub> = 0.59, p = 0.03) and both of these were correlated with feces. No statistically significant
268 correlations were found between trace element concentrations in wool and the internal tissues. Spearman's
269 correlation tests on trace element concentrations within tissues produced more occasions of statistically
270 significant correlations, i.e. out of the 224 combinations ca. 25% (n=56) were statistically significant (p≤0.05;
Table S5 to S12). Yet, for wool specifically, only three such correlations were found and all were positive; Zn and Se ($r_s$ = 0.82, p<0.01), As and Se ($r_s$ = 0.62, p<0.05), and As and Pb ($r_s$ = 0.68, p<0.01) (Table S10).

273

274

## Discussion

276

To understand the link between trace elements and the health of muskoxen in general, and the potential correlation between wool and internal tissues specifically, mapping the trace element distribution within and between different (muskox) tissues is an essential first step.

280

### Distribution of essential trace elements throughout the muskoxen body

As evident from the windrose plot (Figure 1), copper was found to be most abundant in the liver compared to the other tissues, aligning with its role in enzymatic processes and consistent with what is known of Cu metabolism and storage in mammals [53-55]. Other tissues showed low to minimal Cu levels, which underscores the central role of liver in e.g. homeostasis and the risk of hepatic accumulation in ruminants [55-56]. That Cu could also be found in feces is consistent with the known biliary elimination pathways of Cu and that excretion via feces may act as a Cu regulatory mechanism [57]. Wool, however, only contained trace levels of Cu, which suggests a limited correspondence between wool and Cu-rich organs like the liver – a notion that is further supported by the Spearman's correlation tests which found no correlation between the two tissues ($r_s$ = 0.44, p = 0.12; Table S4).

291

Compared to Cu, Zn is more evenly distributed amongst tissues and is notably present in wool, but also in muscle, hoof, and feces (Figure 1). This suggests some degree of systemic reflection and is also consistent with the involvement of Zn in multiple physiological processes such as immune function, epithelial integrity, and enzyme activity [58]. Similar distribution patterns have been reported in domestic ruminants, where Zn levels in peripheral tissues have been considered as reliable indicators of whole-body Zn status [59]. However, similar to previous work on the ionomes of red deer and wild boar [60], we did not find consistent patterns for Zn distribution throughout the body between the different individual muskoxen, as the patterns for Zn concentrations in the different internal tissues varied considerably (Table S1). This indicates that even though the distribution may be relatively even between tissues and a strong tendency can be seen, the use of easily

271

272

273

274

275

276

To understand the link between trace elements and the health of muskoxen in general, and the potential correlation between wool and internal tissues specifically, mapping the trace element distribution within and between different (muskox) tissues is an essential first step.

280

281

As evident from the windrose plot (Figure 1), copper was found to be most abundant in the liver compared to the other tissues, aligning with its role in enzymatic processes and consistent with what is known of Cu metabolism and storage in mammals [53-55]. Other tissues showed low to minimal Cu levels, which underscores the central role of liver in e.g. homeostasis and the risk of hepatic accumulation in ruminants [55-56]. That Cu could also be found in feces is consistent with the known biliary elimination pathways of Cu and that excretion via feces may act as a Cu regulatory mechanism [57]. Wool, however, only contained trace levels of Cu, which suggests a limited correspondence between wool and Cu-rich organs like the liver – a notion that is further supported by the Spearman's correlation tests which found no correlation between the two tissues ($r_s$ = 0.44, p = 0.12; Table S4).

281

As evident from the windrose plot (Figure 1), copper was found to be most abundant in the liver compared to the other tissues, aligning with its role in enzymatic processes and consistent with what is known of Cu metabolism and storage in mammals [53-55]. Other tissues showed low to minimal Cu levels, which underscores the central role of liver in e.g. homeostasis and the risk of hepatic accumulation in ruminants [55-56]. That Cu could also be found in feces is consistent with the known biliary elimination pathways of Cu and that excretion via feces may act as a Cu regulatory mechanism [57]. Wool, however, only contained trace levels of Cu, which suggests a limited correspondence between wool and Cu-rich organs like the liver – a notion that is further supported by the Spearman's correlation tests which found no correlation between the two tissues ($r_s$ = 0.44, p = 0.12; Table S4).

291

Compared to Cu, Zn is more evenly distributed amongst tissues and is notably present in wool, but also in muscle, hoof, and feces (Figure 1). This suggests some degree of systemic reflection and is also consistent with the involvement of Zn in multiple physiological processes such as immune function, epithelial integrity, and enzyme activity [58]. Similar distribution patterns have been reported in domestic ruminants, where Zn levels in peripheral tissues have been considered as reliable indicators of whole-body Zn status [59]. However, similar to previous work on the ionomes of red deer and wild boar [60], we did not find consistent patterns for Zn distribution throughout the body between the different individual muskoxen, as the patterns for Zn concentrations in the different internal tissues varied considerably (Table S1). This indicates that even though the distribution may be relatively even between tissues and a strong tendency can be seen, the use of easily
accessible tissues, such as wool, to assess the Zn status in muskox, remains unconfirmed, as no statistically
significant correlation could be found between wool and any of the internal tissues at the p = <0.05 cut off level,
potentially attributable to our small sample size (e.g. r<sub>s</sub> = 0.53, p = 0.054 for wool vs liver; Table S4).

Selenium concentrations were highest in muskox kidneys, while the concentrations were much lower in all other tissues, which is consistent with the metabolic role and known biological storage patterns of Se [61-62]. This pattern reflects the tightly regulated nature of Se metabolism, given its dual role as both an essential micronutrient and a potential toxin [63-67]. The kidney's prominent role in Se accumulation aligns with findings in both wild and domestic ruminants, where renal and hepatic tissues are considered the most reliable for Se status assessment [64-65, 67]. Wool, however, contains only minor amounts of Se, indicating a weak reflection of internal Se storage, which is also supported by the lack of a correlation between e.g. wool and liver (r<sub>s</sub> = -0.01, p = 0.976). Overall, these results suggest a limited utility of muscle, hoof, and wool samples for estimating bodily Se status in the Dovre muskoxen.

Similar to Cu and Se, Mo also exhibited a selective accumulation, with the highest concentrations found in the liver and kidney, and to some extent also in feces, while low to negligible concentrations were found in the remaining tissues, including wool. This pattern reflects, in part, the involvement of Mo in detoxification processes, yet in spite of the well-known antagonistic interaction of Mo with Cu, i.e. via the formation of thiomolybdate compounds in the rumen, a statistically significant correlation between the two elements could only be found in blood and feces [68-70]. The low systemic distribution of Mo therefore suggests some limitations of using non-visceral tissues – as opposed to soft internal / visceral organs – for assessing internal Mo concentrations, which is also supported by the lack of correlation between e.g. wool and liver (r<sub>s</sub> = -0.51, p = 0.067).

Distribution of non-essential trace elements throughout the muskoxen body

Unlike the essential elements, some general patterns in terms of distribution could be found for the non-essential
elements (Figure 2, Table S1). Similar to findings observed in Svalbard reindeer (*Rangifer tarandus*
*platyrhynchus*) [71], we observed a trend of most non-essential trace elements (i.e. As, Ba, Pb) being higher in
feces than the other tissues, which suggests that excretion of feces acts as an effective pathway of elimination
for non-essential trace elements.
331

332

More specifically, As was predominantly concentrated in feces and, to some extent, in wool, with minor to negligible amounts observed in internal organs or peripheral tissues (Figure 2, Table 1 and S1). This suggests that As is largely excreted via the gastrointestinal tract which is consistent with its known elimination through bile, urine, and feces in mammals [72-74]. However, the somewhat elevated levels in the wool are also consistent with previous studies showing that As tends to accumulate in hair [75-76], yet precaution is still needed when inferring bodily concentrations of As using wool as no statistically significant correlations could be found for As in any of the sampled tissues (e.g. r<sub>s</sub> = 0.24, p = 0.417 for wool vs liver).

333

334

335

336

337

338

339

340

Cadmium exhibited strong localization in the kidney, with minor accumulation in the liver and somewhat elevated levels in feces – indicative of excretory processes –, and minimal presence in all other tissues (Figure 2, Table S1). This is consistent with cadmium's well-established tropism for renal tissue, where it accumulates over time due to its high affinity for metallothionein proteins [77]. The high Cd levels in the kidneys compared to other tissues have also been documented in several mammalian species, including other ungulates [19, 78-79], and is to be expected based on prior knowledge of Cd toxicokinetics and accumulation patterns [22, 80-81]. For example, accumulation of Cd in kidneys of wild and domestic ruminants have been shown to be a reliable biomarker of chronic Cd exposure, particularly in animals near urban or contaminated areas [82]. However, based on the low concentrations found in wool from the muskoxen studied here, as well as the lack of correlation for Cd between tissues (e.g. r<sub>s</sub> = -0.22, p = 0.445 for wool vs liver), it appears as if the ability of wool to act as a monitoring tool for bodily Cd remains rather limited.

341

342

343

344

345

346

347

348

349

350

351

352

Similar to As, the concentration of Ba was highest in feces, and was, to a lesser extent, detected in spleen and muscle, with low concentrations in all other remaining tissues (Figure 2, Table S1). Few studies have looked at the ingestion and distribution patterns of Ba in ruminants, but the pattern found here would suggest that Ba is poorly absorbed and that it is largely eliminated through the gastrointestinal tract, with limited systemic uptake. These findings are consistent with prior reports indicating low tissue retention of Ba in humans and rapid excretion via urine and feces [83]. This route of elimination would suggest that feces may be suitable for evaluating Ba body burden while also indicating that wool may be less appropriate as no statistically significant correlation could be found for Ba between wool and any of the other tissues (e.g. r<sub>s</sub> = 0.24, p = 0.417 for wool vs liver).

353

354

355

356

357

358

359

360
361

362

363

364

365

366

367

368

369

370

371

372

373

Lead also showed prominent localization in feces, while other tissues showed low to moderate levels (Figure 2, Table S1). These results are to be expected given the dual nature of Pb kinetics, i.e. that a portion of the Pb is rapidly eliminated through bile and feces, while the remainder is sequestered and stored in soft tissues and bone [84-85]. Although we did not have access to any bone samples within this study, others have reported that concentrations of Pb in liver and kidney in ruminants can reflect recent or ongoing exposure, but also that the majority of the body burden resides in skeletal tissue more so than in soft tissues [85-86]. The fact that we did not find any correlations between Pb concentrations in wool and other bodily tissues (e.g. r<sub>s</sub> = -0.02, p = 0.964 for wool vs liver) is therefore not surprising, and suggests that similar to As, Cd, and Ba, the use of wool to infer bodily concentrations of Pb is limited and that bones or soft tissues, such as the kidney or liver, remain essential for assessing sub-chronic accumulation of Pb in wildlife.

Wool as a potential non-invasive proxy of internal tissue concentrations

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

Wool is often considered a non-invasive matrix for trace element monitoring, and multiple studies have shown its potential utility to infer animal health and population performance [16, 20, 29-34]. For example, Winter et al [17] showed that trace element concentrations in hair could be linked to the presence of hoof disease in elk, and similar results have also been reported for deer in Denmark, where van Beest et al [19] reported a link between trace elements in hair and overall body condition score of individual deer. However, and also similar to the results of van Beest et al. [19], our results here suggest that the correlation between trace element concentrations in wool to those in internal tissues is limited as no significant correlations were observed. The output of the PCA biplot (Figure 3) provides further support for this, i.e. for the Dovre muskox population, wool tends to cluster near Zn-rich tissues such as muscle and hoof, whereas for the other essential elements (Cu, Se and Mo) wool appears spatially and chemically distinct from the known primary storage tissues (liver, kidney). Moreover, wool shows no alignment with the tissue signatures of non-essential elements, particularly those concentrated in excretory organs such as the kidney (Cd) or the excretory pathway via feces (As, Ba and Pb). Thus, based on our findings wool does not appear to reliably reflect the concentration of the here targeted trace elements found in the internal tissues. This calls into question its general utility for assessing internal trace element status, particularly for elements with narrow homeostatic regulation or complex transport mechanisms.

389
With that said, previous studies have shown a link between trace element concentrations within hair [32] as well as between concentrations in wool/hair and health of wildlife, at least on a population level [16, 18, 19-20]. For example, Mosbacher et al [16] showed that concentrations of Cu, Se and Mo all were linked to annual calf recruitment rates in muskoxen, and Dickinson et al [20] corroborated this finding using multiple muskox populations across the Arctic region. This strongly suggests that though we cannot directly link trace element concentrations in wool to those of internal tissues, the potential link between trace elements in hair and overall animal health should not be dismissed. For example, it has been shown that turnover rates of various trace elements can differ markedly, both between tissues and between elements within the same tissue [87-89], making direct comparisons and interpretations of correlations (or lack thereof) rather complicated. The link between trace elements in hair and animal health can also be inferred from our findings here as the average Cu, Se, and Mo concentrations in muskox wool from Zackenberg [16], as well as in a wider range of muskox populations in North America [20], are generally higher than what we observe for the muskox population at Dovrefjell. The exception to this being Zn, where concentrations in wool from Dovrefjell (91.2 mg kg⁻¹ w.w.) are similar to concentrations seen in growing populations across North America (~92.5 mg kg⁻¹ w.w.; [20]), and higher than concentrations found for the muskox population in Zackenberg (~75.5 mg kg⁻¹ w.w.; [16]). It is also worth noting that average concentrations of Cu, Zn, Se and Mo in wool from the Dovre population, all fall below the thresholds provided by both Mosbacher et al [16] and Dickinson et al [20], indicating that the overall health of the Dovre population might be diminished. Although no direct health biomarkers are included in this study, previous studies have highlighted some challenges towards the fitness and overall health of the Dovre muskoxen population such as a lack of genetic diversity [90] and epizootic outbreaks of e.g. *Pasteurella* spp., *Mycoplasma* spp., and parapox virus [46-47, 50]. This suggests that while the precise role of trace elements in these fitness challenges remains uncertain, clarifying it should be a priority for future studies.

Although the method, and timing of collection varied between the Mosbacher et al. [16] study (i.e. fresh ground collected wool collected during the local shedding season), the Dickinson et al. [20] study (i.e. ground collected wool as well as shaved directly from the animal), and our study (i.e. wool pulled from the rump, just prior to the onset of the local shedding season), all three studies focused on recent, annually produced, metabolically inert wool whose elemental composition was fixed during the preceding growth season. As such, neither differences in the timing of shedding nor the method of collection between regions would alter the biological information contained in the wool. The differences in trace element concentrations between the Dovre population and
muskox populations elsewhere are therefore more likely attributed to underlying environmental conditions such
as differences in local geochemistry, vegetation, and climate [3, 22, 27], as well as the demographic composition
of animals sampled as individual factors have been shown to affect trace element concentrations in ungulates
[26, 91-92]. For example, numerous studies suggest that sex influences trace element status, with for example
differing nutrient needs for females during pregnancy and sex-dependent differences in nutrient metabolism
[26]. Another factor that could explain the within population differences in trace element patterns/distributions
is age, which is well-known to influence the non-essential trace element status in mammals. Although the link
between essential trace elements and age is less explored than sex, some studies have reported Cd accumulation
with age in moose [92], As, Cd, and Pb accumulation with age in red deer [93-94], and mercury (Hg)
accumulation with age in Alaskan reindeer [91]. The individual differences observed in our study are therefore
not unexpected. It is worth noting though that our study largely contains pregnant, adult females, and as such the
ranges provided per tissue are likely affected by age, sex, and pregnancy status as, for example, the turnover
rates of trace elements may shift during the course of the pregnancy [95]. Further, the only two males included
were both young (i.e. one yearling and one calf; Table S1), making comparisons between sex and age difficult.

434

Based on our data as well as the published literature, it is clear that there is often a lack of consistency in
correlations of trace elements between and within tissues, which underlines the importance of a species-specific
approach to mapping out the ionomic status and unraveling the nuances of trace element accumulation between
tissues with different turnover rates. It should be noted though that the relatively small sample size available
within this study (i.e. 7 adult animals, 3 sub-adults, 2 yearlings and 2 calves) may limit our capacity to detect
strong effects and correlations. Nonetheless, similar to our finding of few correlations between trace element
concentrations across tissues, other studies – targeting at least three different tissues – have also noted this (lack
of) cross tissue pattern in e.g. muskoxen in West Greenland [26], caribou (Rangifer tarandus caribou) in
northwestern British Columbia [25], red deer (Cervus elaphus) in Poland [86], red and fallow deer (Dama
dama) in Denmark [19], and wild boar (Sus scrofa) in Slovakia [22]. Combined, this suggest that even though
our sample size is limited, the patterns – or rather lack thereof – align with the published literature.

446

447

448 **Conclusion**

449
This study provides the first comprehensive mapping of trace element concentrations across multiple tissues in muskoxen, and the first study of this nature on the muskox population at Dovrefjell. While all targeted elements were detectable in wool, our results show that elemental distributions vary substantially between individuals and between tissues, and that correlations between wool and internal organs are weak and not statistically not significant. These findings highlight the complexity of using wool as a standalone proxy for internal trace element status. Nevertheless, previously published population-level associations between trace element concentrations in wool and population demographics suggest that wool may still offer value in broader ecological assessments. Given the variability in trace element patterns between individuals and across populations, future work should prioritize expanding sample sizes, integrating health biomarkers, and accounting for local environmental and demographic factors. Until then, a multi-tissue approach remains essential for accurately assessing ionomic profiles and interpreting trace element data in Arctic ungulates.

461

462

## 463 Statements & Declarations

### 464 Funding

Financial support was provided by the French National Research Agency (ANR) Young Researcher (JCJC) Grant awarded to SVH (ANR-21-CE34-0001, ATCAF-project).

467

### 468 Ethics Approval and Consent to Participate

This study did not require official or institutional ethical approval as none of the muskoxen were killed for the purpose of this study. Instead, all animals were culled as part of the annual muskox population management plan under the jurisdiction of Miljødirektoratet (the Norwegian Environment Agency). Certified game managers shot the muskoxen, and all samples were collected post-mortem and stored locally before being donated to this project.

474

### 475 Competing interests

The authors declare no competing interest.

477

### 478 Author contributions
479 SVH designed the study in close discussion with NMS and FMvB. SVH was responsible for all sample processing, and treatment, as well as the TQ-ICP-MS analyses and quality assurance. RW and FMvB performed the statistical analyses and generated the figures, in close discussion with SVH. All authors participated in the interpretation of results. RW and SVH led the writing of the manuscript with input of all authors.

483

484 **Data availability**

485 The complete dataset is provided in the Supplementary Materials (Table S1).

486

487 **Supplementary Information**

488 Absolute concentrations from trace element analysis of tissues and associated meta-data of the animals included are given in Table S1. Results of calculated moisture content of each tissue are reported in Table S2. Results from quality control, including specifics of certified reference materials used, and reproducibility of results from ICP-MS, are provided in Table S3. Results of Spearman's correlation test of correlation between trace element concentrations in different muskoxen tissues is provided in Table S4. Spearman's correlation test for correlation of trace elements within various tissues are provided in Tables S5-12.

494

495 **References**

496 1. Post E, Forchhammer MC, Bret-Harte MS, Callaghan TV, Christensen TR, Elberling B et al (2009) Ecological Dynamics Across the Arctic Associated with Recent Climate Change. *Science*, **325**(5946), 1355-1358.

497 2. Rantanen M, Karpechko AY, Lipponen A, Nordling K, Hyvärinen O, Ruosteenoja K et al. (2022) The Arctic has warmed nearly four times faster than the globe since 1979. *Communications Earth & Environment*, **3**(1), 168.

498 3. van Beest FM, Beumer LT, Andersen AS, Hansson SV, Schmidt NM (2021) Rapid shifts in Arctic tundra species' distributions and inter-specific range overlap under future climate change. *Diversity and Distributions*, **27**(9), 1706-1718.

499 4. García Criado M, Myers-Smith IH, Bjorkman AD, Elmendorf SC, Normand S, Aastrup P et al (2025) Plant diversity dynamics over space and time in a warming Arctic. *Nature*, **642**(8068), 653-661.

500 5. Lorenzen ED, Nogués-Bravo D, Orlando L, Weinstock J, Binladen J, Marske KA et al (2011) Species-specific responses of Late Quaternary megafauna to climate and humans. *Nature*, **479**(7373), 359-364.

501 6. Canteri E, Brown SC, Schmidt NM, Heller R, Nogués-Bravo D, Fordham DA (2022) Spatiotemporal influences of climate and humans on muskox range dynamics over multiple millennia. *Global Change Biology*, **28**(22), 6602-6617.

502 7. Cuyler C, Rowell J, Adamczewski J, Anderson M, Blake J, Bretten T et al (2020) Muskox status, recent variation, and uncertain future. *Ambio*, **49**(3), 805-819.

503 8. Mosbacher JB, Kristensen DK, Michelsen A, Stelvig M, Schmidt NM (2016) Quantifying Muskox Plant Biomass Removal and Spatial Relocation of Nitrogen in a High Arctic Tundra Ecosystem. *Arctic, Antarctic, and Alpine Research*, **48**(2), 229-240.
517
518
519

9. Aggerbeck MR, Nielsen TK, Mosbacher JB, Schmidt NM, Hansen LH (2022) Muskoxen homogenise soil microbial communities and affect the abundance of methanogens and methanotrophs. *Science of The Total Environment, 827*, 153877.

520
521

10. Post E, Pedersen C (2008) Opposing plant community responses to warming with and without herbivores. *Proceedings of the National Academy of Sciences, 105*(34), 12353-12358.

522
523

11. Mosbacher JB, Michelsen A, Stelvig M, Hjermstad-Sollerud H, Schmidt NM (2019) Muskoxen Modify Plant Abundance, Phenology, and Nitrogen Dynamics in a High Arctic Fen. *Ecosystems*, 22(5), 1095-1107.

524
525

12. Falk JM, Schmidt NM, Christensen TR, Ström L (2015) Large herbivore grazing affects the vegetation structure and greenhouse gas balance in a high arctic mire. *Environmental Research Letters*, 10(4), 045001.

526
527

13. White RG, Rowell JE, Hauer WE (1997) The role of nutrition, body condition and lactation on calving success in muskoxen. *Journal of Zoology*, 243(1), 13-20.

528
529
530

14. Cook RC, Cook JG, Stephenson TR, Myers WL, McCorquodale SM, Vales DJ et al (2010) Revisions of Rump Fat and Body Scoring Indices for Deer, Elk, and Moose. *The Journal of Wildlife Management*, 74(4), 880-896.

531
532

15. Baxter I (2010) Ionomics: The functional genomics of elements. *Briefings in Functional Genomics*, 9(2), 149-156.

533
534

16. Mosbacher JB, Desforges J-P, Michelsen A, Hansson SV, Stelvig M, Eulaers I et al (2022) Hair mineral levels as indicator of wildlife demographics?—a pilot study of muskoxen. *Polar Research*, 41.

535
536
537

17. Winter SN, Fernandez MDP, Taylor KR, Wild MA (2022) Associations between hair trace mineral concentrations and the occurrence of treponeme-associated hoof disease in elk (Cervus canadensis). *BMC Vet Res*, 18(1), 446.

538
539
540

18. Rioux È, Pelletier F, Mosbacher JB, Lesmerises F, St-Louis R, Kutz S et al (2022) Links between individual performance, trace elements and stable isotopes in an endangered caribou population. *Global Ecology and Conservation*, 38, e02234.

541
542
543

19. van Beest FM, Schmidt NM, Frederiksen ML, Krogh AKH, Petersen HH, Hansson SV (2024) Direct and Indirect Linkages Between Trace Element Status and Health Indicators - a Multi-tissue Case-Study of Two Deer Species in Denmark. *Biol Trace Elem Res*, 202(8), 3623-3638.

544
545

20. Dickinson ER, Mosbacher JB, Arnison C, Beckmen K, Côté SD, Di Francesco J et al (2025) Qiviut Trace and Macro Element Profile Reflects Muskox Population Trends. *Ecology and Evolution*, 15(2), e71020.

546
547
548

21. Lazarus M, Orct T, Blanuša M, Vicković I, Šoštarić B (2008) Toxic and essential metal concentrations in four tissues of red deer (*Cervus elaphus*) from Baranja, Croatia. *Food Additives & Contaminants: Part A*, 25(3), 270-283.

549
550
551

22. Gašparík J, Binkowski ŁJ, Jahnátek A, Šmehýl P, Dobiaš M, Lukáč N et al (2017) Levels of Metals in Kidney, Liver, and Muscle Tissue and their Influence on the Fitness for the Consumption of Wild Boar from Western Slovakia. *Biol Trace Elem Res*, 177(2), 258-266.

552
553

23. Aastrup P, Riget F, Dietz R, Asmund G (2000) Lead, zinc, cadmium, mercury, selenium and copper in Greenland caribou and reindeer (Rangifer tarandus). *Sci Total Environ*, 245(1-3), 149-159.

554
555
556

24. Vikøren T, Kristoffersen AB, Lierhagen S, Handeland K (2011) A comparative study of hepatic trace element levels in wild moose, roe deer, and reindeer from Norway. *Journal of Wildlife Diseases*, 47(3), 661-672.

557
558
559

25. Jutha N, Jardine C, Schwantje H, Mosbacher JB, Kinniburgh D, Kutz S (2022) Evaluating the use of hair as a non-invasive indicator of trace mineral status in woodland caribou (Rangifer tarandus caribou). *PLoS One*, 17(6), e0269441.

560
561
562

26. Ribeiro DM, Raundrup K, Mourato MP, Almeida AM (2023) The Effect of Species and Sex on the Element Content of Muskox (Ovibos moschatus) and Caribou (Rangifer tarandus groenlandicus) Tissues. *Biol Trace Elem Res*, 201(10), 4718-4725.

563
564
565

27. van Beest FM, Schmidt NM, Stewart L, Hansen LH, Michelsen A, Mosbacher JB et al (2023) Geochemical landscapes as drivers of wildlife reproductive success: Insights from a high-Arctic ecosystem. *Science of The Total Environment*, 903, 166567.

566
567

28. Kincaid RL (2000) Assessment of trace mineral status of ruminants: A review. *Journal of Animal Science*, 77(suppl_E), 1-10.
568
569
570

29. O'Hara TM, Carroll G, Barboza P, Mueller K, Blake J, Woshner V et al (2001) Mineral and heavy metal status as related to a mortality event and poor recruitment in a moose population in Alaska. *J Wildl Dis*, 37(3), 509-522.

571
572
573

30. Wittemyer G, Cerling TE, Douglas-Hamilton I (2009) Establishing chronologies from isotopic profiles in serially collected animal tissues: An example using tail hairs from African elephants. *Chemical Geology*, 267(1), 3-11.

574
575
576

31. von Holstein ICC, Penkman KEH, Peacock EE, Collins MJ (2014) Wet degradation of keratin proteins: linking amino acid, elemental and isotopic composition. *Rapid Communications in Mass Spectrometry*, 28(19), 2121-2133.

577
578
579

32. Herrada A, Bariod L, Saïd S, Rey B, Bidault H, Bollet Y, et al (2024) Minor and trace element concentrations in roe deer hair: A non-invasive method to define reference values in wildlife. *Ecological Indicators*, 159, 111720.

580
581

33. Trapp SE, Flaherty EA (2017) Noninvasive and cost-effective trapping method for monitoring sensitive mammal populations. *Wildlife Society Bulletin*, 41(4), 770-775.

582
583

34. Schilling A-K, Mazzamuto MV, Romeo C (2022) A Review of Non-Invasive Sampling in Wildlife Disease and Health Research: What's New? *Animals*, 12(13), 1719.

584
585

35. Flood PF, Stalker MJ, Rowell JE (1989) The hair follicle density and seasonal shedding cycle of the muskox (*Ovibos moschatus*). *Canadian Journal of Zoology* 67(5): 1143-1147.

586
587
588

36. Katz SA, Chatt A. (1994) The use of hair as a biopsy tissue for trace elements in the human body. In: *Application of hair as an indicator for trace elements exposure in man. A review*. NAHRES-22. Pp. 1-23. Vienna: International Atomic Energy Agency.

589
590

37. Andreassen S-A (Ed.) (2017) *Forvaltningsplan for moskusbestanden på Dovrefjell*. Rapport nr. 4 – 2017. Trondheim: Fylkesmannen i Sør-Trøndelag, Miljøvernavdelingen. ISBN: 978-82-7540-212-5.

591
592
593

38. Asbjørnsen EJ, Sæther BE, Linnell JDC, Engen S, Anersen R, Bretten T (2005) Predicting the growth of a small introduced muskox population using population prediction intervals. *Journal of Animal Ecology*, 74(4), 612-618.

594
595

39. Michelsen O, Syverhuset AO, Pedersen B, Holten JI (2011) The Impact of Climate Change on Recent Vegetation Changes on Dovrefjell, Norway. *Diversity*, 3(1), 91-111.

596
597
598

40. Hagen D, Gaare E, Erikstad L, Hoem SA (2006) Beiteressurskartlegging i Snøhetta villreinområde - kartlegging av beite for villrein, moskus og sau med bruk av satellittbildetolking og visuell punkttaksering fra helikopter. NINA Rapport 135. 52 s.

600
601
602

41. Ihl C, Klein DR (2001) Habitat and Diet Selection by Muskoxen and Reindeer in Western Alaska. *The Journal of Wildlife Management* 65(4): 964-972.

603
604
605

42. Rozenfeld SB, Gruzdev AR, Sipko TP, Tikhonov AN (2012) Trophic relationships of muskoxen (Ovibos moschatus) and reindeer (*Rangifer tarandus*) on Wrangel Island. *Biology Bulletin* 39(9): 779-787.

606
607
608

43. Mosbacher JB, Michelsen A, Stelvig M, Hendrichsen DK, Schmidt NM (2016) Show Me Your Rump Hair and I Will Tell You What You Ate – The Dietary History of Muskoxen (*Ovibos moschatus*) Revealed by Sequential Stable Isotope Analysis of Guard Hairs. *PLOS ONE* 11(4): e0152874.

609
610
611

44. Schmidt NM, Mosbacher JB, Vesterinen EJ, Roslin T, Michelsen A (2018) Limited dietary overlap amongst resident Arctic herbivores in winter: complementary insights from complementary methods. *Oecologia* 187(3): 689-699.

612
613

45. Prewer E, Vilaça ST, Bird S, Kutz S, Leclerc L-M, Kyle CJ (2023) Metabarcoding of fecal pellets in wild muskox populations reveals negative relationships between microbiome and diet alpha diversity. *Ecology and Evolution* 13(6): e10192.

614
615
616

46. Ytrehus B, Bretten T, Bergsjø B, Isaksen K (2008) Fatal Pneumonia Epizootic in Musk Ox (*Ovibos moschatus*) in a Period of Extraordinary Weather Conditions. *EcoHealth*, 5(2), 213-223.

617
618

47. Davidson RK, Amundsen H, Lie NO, Luyckx K, Robertson LJ, Verocai GG et al (2014) Sentinels in a climatic outpost: Endoparasites in the introduced muskox (Ovibos moschatus wardi) population of Dovrefjell, Norway. *International Journal for Parasitology: Parasites and Wildlife*, 3(2), 154-160.

48. Schmidt NM, Grøndahl C, Evans AL, Desforges JP, Blake J, Hansen LH, et al. (2020). On the interplay between hypothermia and reproduction in a high arctic ungulate. *Scientific Reports*, 10(1), 1514.
619

620

621

49. Kafle, P, Peller P, Massolo A, Hoberg E, Leclerc L-M, Tomaselli M, et al. (2020) Range expansion of muskox lungworms track rapid arctic warming: implications for geographic colonization under climate forcing. *Scientific Reports*, 10(1), 17323.

622

623

624

50. Handeland K, Tengs T, Kokotovic B, Vikøren T, Ayling RD, Bergsjø B et al (2014) Mycoplasma ovipneumoniae--a primary cause of severe pneumonia epizootics in the Norwegian Muskox (Ovibos moschatus) population. *PLoS One*, 9(9), e106116.

625

626

627

51. Brumbaugh WG, Schmitt CJ, May TW (2005) Concentrations of Cadmium, Lead, and Zinc in Fish from Mining-Influenced Waters of Northeastern Oklahoma: Sampling of Blood, Carcass, and Liver for Aquatic Biomonitoring. [journal article], *Archives of Environmental Contamination and Toxicology*, 49(1), 76-88.

628

52. R Development Core Team (2024) R: A Language and Environment for Statistical Computing.

629

630

53. La Fontaine S, Mercer JF (2007) Trafficking of the copper-ATPases, ATP7A and ATP7B: role in copper homeostasis. *Arch Biochem Biophys*, 463(2), 149-167.

631

632

54. Suttle NF (2012) Copper Imbalances in Ruminants and Humans: Unexpected Common Ground. *Advances in Nutrition*, 3(5), 666-674.

633

634

635

55. Clarkson AH, Paine S, Martín-Tereso J, Kendall NR (2020) Copper physiology in ruminants: trafficking of systemic copper, adaptations to variation in nutritional supply and thiomolybdate challenge. *Nutr Res Rev*, 33(1), 43-49.

636

637

638

639

56. Daniel J-B, Brugger D, van der Drift S, van der Merwe D, Kendall N, Windisch W. et al (2023) Zinc, Copper, and Manganese Homeostasis and Potential Trace Metal Accumulation in Dairy Cows: Longitudinal Study from Late Lactation to Subsequent Mid-Lactation. *The Journal of Nutrition*, 153(4), 1008-1018.

640

641

642

57. Gourlez E, Beline F, Dourmad J-Y, Monteiro AR, Guiziou F, Le Bihan A, et al (2024) The fate of Cu and Zn along the feed-animal-excreta-effluent continuum in swine systems according to feed and effluent treatment strategies. *Journal of Environmental Management*, 354, 120299.

643

644

58. Duffy R, Yin M, Redding LE (2023) A review of the impact of dietary zinc on livestock health. *Journal of Trace Elements and Minerals*, 5, 100085.

645

646

59. Underwood EJ, Suttle NF (1999) The Mineral Nutrition of Livestock (3rd ed.). CABI Publishing, CAB International, Wallingford, 614 pp. ISBN 085199 128 9

647

648

649

60. Wenting E, Siepel H, Jansen PA (2024) Variability of the Ionome of Wild Boar (Sus scrofa) and Red Deer (Cervus elaphus) in a Dutch National Park, with Implications for Biomonitoring. *Biological Trace Element Research*, 202(6), 2518-2546.

650

651

61. Langlands J, Bowles J, Donald G, Smith A (1984) Deposition of copper, manganese, selenium and zinc in Merino sheep. *Australian Journal of Agricultural Research*, 35(5), 701-707.

652

653

62. Koenig KM, Rode LM, Cohen RDH, Buckley WT (1997) Effects of diet and chemical form of selenium on selenium metabolism in sheep. *Journal of Animal Science*, 75(3), 817-827.

654

655

63. Muth OH, Binns W (1964) Selenium toxicity in domestic animals. *Annals of the New York Academy of Sciences*, 111(2), 583-590.

656

657

64. Ammerman CB, Miller SM (1975) Selenium in Ruminant Nutrition: A Review.1. *Journal of Dairy Science*, 58(10), 1561-1577.

658

659

65. Cristaldi LA, McDowell LR, Buergelt CD, Davis PA, Wilkinson NS, Martin FG (2005) Tolerance of inorganic selenium in wether sheep. *Small Ruminant Research*, 56(1), 205-213.

660

661

66. Flueck WT, Smith-Flueck JM, Mionczynski J, Mincher BJ (2012) The implications of selenium deficiency for wild herbivore conservation: a review. *European Journal of Wildlife Research*, 58(5), 761-780.

662

663

664

67. Netto AS, Zanetti MA, Correa LB, Del Claro GR, Salles MS, Vilela FG (2014) Effects of dietary selenium, sulphur and copper levels on selenium concentration in the serum and liver of lamb. *Asian-Australas J Anim Sci*, 27(8), 1082-1087.

665

666

68. Mason J (1986) Thiomolybdates: Mediators of molybdenum toxicity and enzyme inhibitors. *Toxicology*, 42(2), 99-109.

667

668

69. Suttle NF (1991) The interactions between copper, molybdenum, and sulphur in ruminant nutrition. *Annu Rev Nutr*, 11, 121-140.

669

670

70. Gould L, Kendall NR (2011) Role of the rumen in copper and thiomolybdate absorption. *Nutrition Research Reviews*, 24(2), 176-182.
671 71. Pacyna AD, Koziorowska K, Chmiel S, Mazerski J, Polkowska Ż (2018) Svalbard reindeer as an indicator of ecosystem changes in the Arctic terrestrial ecosystem. *Chemosphere*, **203**, 209-218
672 Ward GM (1994) Chapter 9 - Molybdenum Requirements, Toxicity and Nutritional Limits for Man and Animals. In E. R. Braithwaite & J. Haber (Eds.), *Studies in Inorganic Chemistry* (Vol. 19, pp. 452-476): Elsevier.

673 72. Datta BK, Mishra A, Singh A, Sar TK, Sarkar S, Bhattacharya A et al. (2010) Chronic arsenicosis in cattle with special reference to its metabolism in arsenic endemic village of Nadia district West Bengal India. *Science of The Total Environment*, **409**(2), 284-288.

678 73. Das A, Joardar M, Chowdhury NR, De A, Mridha D, Roychowdhury T (2021) Arsenic toxicity in livestock growing in arsenic endemic and control sites of West Bengal: risk for human and environment. *Environmental Geochemistry and Health*, **43**(8), 3005-3025.

681 74. Liu X, Wang J, Deng H, Zhong X, Li C, Luo Y et al (2022) In situ analysis of variations of arsenicals, microbiome and transcriptome profiles along murine intestinal tract. *Journal of Hazardous Materials*, **427**, 127899.

684 75. Valentine JL, Kang HK, Spivey G (1979) Arsenic levels in human blood, urine, and hair in response to exposure via drinking water. *Environmental Research*, **20**(1), 24-32.

686 76. Hindmarsh JT (2002) Caveats in hair analysis in chronic arsenic poisoning. *Clin Biochem*, **35**(1), 1-11.

687 77. Fowler BA (2009) Monitoring of human populations for early markers of cadmium toxicity: a review. *Toxicol Appl Pharmacol*, **238**(3), 294-300.

689 78. Larter NC, Macdonald CR, Elkin BT, Wang X, Harms NJ, Gamberg M et al (2016) Cadmium and other elements in tissues from four ungulate species from the Mackenzie Mountain region of the Northwest Territories, Canada. *Ecotoxicology and Environmental Safety*, **132**, 9-17.

692 79. Andersson Stavridis M, Pollestad BM, Veiberg V, Mikkelsen Ø, Ciesielski TM, Jenssen BM (2025) Toxic metals and other elements in Svalbard reindeer: Establishing baselines and assessing non-invasive sampling for biomonitoring. *Science of The Total Environment*, **961**, 178226.

695 80. Kramárová M, Peter M, Jaroslav S, Frieda T, Alena J, Jozef G et al (2005) Distribution of Cadmium and Lead in Liver and Kidney of Some Wild Animals in Slovakia. *Journal of Environmental Science and Health, Part A*, **40**(3), 593-600.

698 81. Jarzyńska G, Falandysz J (2011) Selenium and 17 other largely essential and toxic metals in muscle and organ meats of Red Deer (Cervus elaphus) — Consequences to human health. *Environment International*, **37**(5), 882-888.

701 82. Alonso ML, Benedito JL, Miranda M, Castillo C, Hernández J, Shore RF (2000) Arsenic, cadmium, lead, copper and zinc in cattle from Galicia, NW Spain. *Science of The Total Environment*, **246**(2), 237-248.

703 83. Zaccarini DJ, Lubin D, Sanyal S, Abraham JL (2022) Barium Sulfate Deposition in the Gastrointestinal Tract: Review of the literature. *Diagnostic Pathology*, **17**(1), 99.

705 84. Blaxter KL (1950) Lead as a nutritional hazard to farm livestock. II. The absorption and excretion of lead by sheep and rabbits. *J Comp Pathol*, **60**(2), 140-159.

707 85. Bischoff K, Hillebrandt J, Erb HN, Thompson B, Johns S (2016) Comparison of blood and tissue lead concentrations from cattle with known lead exposure. *Food Additives & Contaminants: Part A*, **33**(10),

709 86. Rumbeiha WK, Braselton WE, Donch D (2001) A retrospective study on the disappearance of blood lead in cattle with accidental lead toxicosis. [Article]. *Journal of Veterinary Diagnostic Investigation*, **13**(5), 373-378.

712 87. Humann-Ziehank, E., Coenen, M., Ganter, M., & Bickhardt, K. (2001). Long-Term Observation of Subclinical Chronic Copper Poisoning in Two Sheep Breeds. *Journal of Veterinary Medicine Series A, 48*(7), 429-439.

715 88. Lane, E. A., Canty, M. J., & More, S. J. (2015). Cadmium exposure and consequence for the health and productivity of farmed ruminants. *Research in Veterinary Science*, **101**, 132-139.

717 89. Gatti, B. S., Bacchi, M. A., Fernandes, M. A., Scotton, K. C., de Nadai Fernandes, E. A., Abdalla, A. L., et al. (2025). Kinetics of 65Zn in Sheep Supplemented with Micro- and Nanoparticles of Zinc Oxide. *Biological Trace Element Research*.

720 90. Thulin C-G, Englund L, Ericsson G, Spong G (2011) The impact of founder events and introductions on genetic variation in the muskox Ovibos moschatus in Sweden. *Acta Theriologica*, **56**(4), 305-314.

722 91. Duffy LK, Duffy RS, Finstad G, Gerlach C (2005) A note on mercury levels in the hair of Alaskan reindeer. *Science of the Total Environment*, **339**(1-3), 273-276.
724
725

92. Danielsson R, Frank A (2009) Cadmium in moose kidney and liver – age and gender dependency, and standardisation for environmental monitoring. *Environmental Monitoring and Assessment*, **157**(1), 73-88.

726
727
728

93. Oropesa AL, Ramos A, Gómez LJ (2022) Toxic and essential metal levels in the hair of red deer (Cervus elaphus) and wild boar (Sus scrofa) for monitoring the contamination in protected areas of South-Western Spain. *Environ Sci Pollut Res Int*, **29**(18), 27430-27442.

729
730
731

94. Cygan-Szczegielniak D, Stasiak K (2022) Effects of age and sex on the content of heavy metals in the hair, liver and the longissimus lumborum muscle of roe deer Capreolus capreolus L. *Environmental Science and Pollution Research*, **29**(7), 10782-10790.

732
733

95. Hostetler, C. E., Kincaid, R. L., & Mirando, M. A. (2003). The role of essential trace elements in embryonic and fetal development in livestock. *The Veterinary Journal*, **166**(2), 125-139.
<table><caption>**Table 1.** Trace element concentrations presented as min, max, and median (in mg kg⁻¹ w.w.) as measured in tissues and sample matrices of muskoxen (*Ovibos moschatus*) culled in the Dovrefjell region of Norway between 2022 and 2023. Detection limits (D.L) is included and was calculated as 3 x standard deviation of the procedural blanks.</caption><thead><tr><th rowspan="2">Tissue</th><th colspan="3">Cu</th><th colspan="3">Zn</th><th colspan="3">Se</th><th colspan="3">Mo</th><th colspan="3">As</th><th colspan="3">Cd</th><th colspan="3">Ba</th><th colspan="3">Pb</th></tr><tr><th>Min</th><th>Max</th><th>Median</th><th>Min</th><th>Max</th><th>Median</th><th>Min</th><th>Max</th><th>Median</th><th>Min</th><th>Max</th><th>Median</th><th>Min</th><th>Max</th><th>Median</th><th>Min</th><th>Max</th><th>Median</th><th>Min</th><th>Max</th><th>Median</th><th>Min</th><th>Max</th><th>Median</th></tr></thead><tbody><tr><td>Blood</td><td>0.38</td><td>1.24</td><td>0.72</td><td>1.57</td><td>3.11</td><td>1.84</td><td>0.03</td><td>0.50</td><td>0.12</td><td>0.0004</td><td>0.0038</td><td>0.0011</td><td>0.0006</td><td>0.0029</td><td>0.0008</td><td>0.0001</td><td>0.0030</td><td>0.0001</td><td>0.13</td><td>0.43</td><td>0.20</td><td>0.010</td><td>0.047</td><td>0.018</td></tr><tr><td>Liver</td><td>1.95</td><td>101.3</td><td>26.9</td><td>13.0</td><td>59.7</td><td>21.4</td><td>0.17</td><td>0.27</td><td>0.22</td><td>0.415</td><td>0.891</td><td>0.647</td><td>0.0022</td><td>0.0081</td><td>0.0034</td><td>0.1613</td><td>1.1311</td><td>0.5103</td><td>0.15</td><td>0.55</td><td>0.29</td><td>0.108</td><td>0.484</td><td>0.210</td></tr><tr><td>Kidney</td><td>1.82</td><td>3.20</td><td>2.26</td><td>22.7</td><td>38.2</td><td>28.0</td><td>0.93</td><td>2.10</td><td>1.11</td><td>0.143</td><td>0.368</td><td>0.208</td><td>0.0014</td><td>0.0057</td><td>0.0042</td><td>0.4268</td><td>13.73</td><td>3.7493</td><td>0.53</td><td>1.98</td><td>0.71</td><td>0.057</td><td>0.114</td><td>0.077</td></tr><tr><td>Spleen</td><td>0.37</td><td>0.87</td><td>0.67</td><td>17.5</td><td>46.8</td><td>31.7</td><td>0.16</td><td>0.35</td><td>0.29</td><td>0.026</td><td>0.098</td><td>0.058</td><td>0.0011</td><td>0.0029</td><td>0.0018</td><td>0.0077</td><td>0.0359</td><td>0.0191</td><td>0.51</td><td>2.6</td><td>1.27</td><td>0.093</td><td>0.478</td><td>0.205</td></tr><tr><td>Muscle</td><td>0.76</td><td>1.88</td><td>1.37</td><td>22.8</td><td>64.3</td><td>41.9</td><td>0.07</td><td>0.61</td><td>0.12</td><td>0.004</td><td>0.142</td><td>0.012</td><td>0.0022</td><td>0.0088</td><td>0.0047</td><td>0.0014</td><td>0.0277</td><td>0.0040</td><td>0.03</td><td>0.18</td><td>0.06</td><td>0.003</td><td>0.043</td><td>0.005</td></tr><tr><td>Wool</td><td>2.69</td><td>4.41</td><td>3.67</td><td>64.5</td><td>205.4</td><td>79.8</td><td>0.09</td><td>0.28</td><td>0.16</td><td>0.010</td><td>0.027</td><td>0.017</td><td>0.0043</td><td>0.0403</td><td>0.0093</td><td>0.0015</td><td>0.0114</td><td>0.0033</td><td>0.95</td><td>2.68</td><td>1.40</td><td>0.073</td><td>0.39</td><td>0.105</td></tr><tr><td>Hoof</td><td>0.54</td><td>1.49</td><td>1.08</td><td>23.5</td><td>64.4</td><td>53.4</td><td>0.13</td><td>0.40</td><td>0.22</td><td>0.005</td><td>0.318</td><td>0.011</td><td>0.0040</td><td>0.0193</td><td>0.0071</td><td>0.0008</td><td>0.0046</td><td>0.0010</td><td>0.31</td><td>1.19</td><td>0.69</td><td>0.034</td><td>0.958</td><td>0.115</td></tr><tr><td>Feces</td><td>1.99</td><td>4.93</td><td>2.71</td><td>24.4</td><td>71.5</td><td>33.3</td><td>0.03</td><td>0.13</td><td>0.05</td><td>0.073</td><td>0.209</td><td>0.125</td><td>0.0375</td><td>0.1261</td><td>0.0541</td><td>0.1496</td><td>0.4370</td><td>0.2060</td><td>24.8</td><td>130.0</td><td>46.43</td><td>1.028</td><td>2.864</td><td>1.371</td></tr><tr><td>D.L.</td><td colspan="3">1.64 x 10<sup>-3</sup></td><td colspan="3">1.17 x 10<sup>-2</sup></td><td colspan="3">5.21 x 10<sup>-5</sup></td><td colspan="3">4.72 x 10<sup>-5</sup></td><td colspan="3">1.81 x 10<sup>-5</sup></td><td colspan="3">1.56 x 10<sup>-5</sup></td><td colspan="3">2.44 x 10<sup>-4</sup></td><td colspan="3">2.73 x 10<sup>-5</sup></td></tr></tbody></table>
Essential Trace Elements

Cu

Se

Zn

Mo

<figure><img src="image_2.png" /></figure>

<figure><img src="image_3.png" /></figure>

<figure><img src="image_4.png" /></figure>

<figure><img src="image_5.png" /></figure>

738

739

740

741

742

743

**Fig. 1** Windrose diagram showing the distribution of concentrations (mg kg⁻¹ wet weight on a log scale) of four essential trace elements (Cu, Zn, Se, and Mo) across eight different tissues and sample matrices from muskoxen (*Ovibos moschatus*) in Dovrefjell, Norway. Each spoke represents a different biological matrix (blood, feces, hoof, kidney, liver, muscle, spleen, and wool), with bar lengths indicating relative concentrations on a log scale for each trace element.
Non-essential Trace Elements

As

<figure><img src="image_6.png" /></figure>

Cd

<figure><img src="image_7.png" /></figure>

Ba

<figure><img src="image_8.png" /></figure>

Pb

<figure><img src="image_9.png" /></figure>

744

745

746

747

748

749

**Fig. 2** Windrose diagram showing the distribution of concentrations (mg kg⁻¹ wet weight on a log scale) of four non-essential trace elements (As, Cd, Ba and Pb) across eight different tissues and sample matrices from muskoxen (*Ovibos moschatus*) in Dovrefjell, Norway. Each spoke represents a different biological matrix (blood, feces, hoof, kidney, liver, muscle, spleen, and wool), with bar lengths indicating relative concentrations on a log scale for each trace element.
<figure><img src="image_10.png" /><figcaption>**Fig. 3** Principal component analysis (PCA) ordination biplot showing the (dis)similarity of trace element (vectors) concentrations measured in the eight tissues and sample matrix analysed from muskoxen (*Ovibos moschatus*, *n*=14) culled in Dovrefjell, Norway. The convex polygons were drawn to highlight overlap or separation in trace element profiles between tissues.</figcaption></figure>