bluuebunny/crossref_metadata_2025 huggingface dataset:
Orientation-induced enhancement in electromagnetic properties of ZnFe2O4/SiO2/PANI core/shell/shell nanostructured disks
Authors: Wang Jiaheng , Or Siu Wing
Published: February 2016

ZnFe2O4/SiO2/PANI (ZSP) core/shell/shell nanostructured disks are prepared and fabricated into paraffin-bonded ZSP composite rings with random, vertical, and horizontal orientations of the easy magnetization planes of the ZSP disks in the paraffin binder in order to study the effect of directional orientation of the easy magnetization planes on their electromagnetic properties. The easy magnetization planes induced by shape anisotropy and oriented by a magnetic field in the vertically oriented ring result in a general enhancement in permeability of 7–60% in the broad UHF–Ku (0.1–18 GHz) bands, while those in the horizontally oriented ring lead to a significant enhancement of 58–1100% in the low-frequency L and S (1–4 GHz) bands, in comparison with the randomly oriented ring. The observed permeability agrees with the theoretical prediction based on the Landau–Lifshitz–Gilbert equation and the Bruggeman’s effective medium theory. The horizontal and vertical arrangements of dipolar polarizations in the vertically and horizontally oriented rings give rise to 3–11% enhancement and weakening in permittivity, respectively, compared to the randomly oriented ring. The enhancement in permeability also improves and broadens the electromagnetic wave absorption in both vertically and horizontally oriented rings, especially in the L and S bands for the horizontally oriented ring.
The design, validation, and performance of Grace
Authors: Zhu Ru
Published: February 2016

The design, validation and performance of Grace, a GPU-accelerated micromagnetic simulation software, are presented. The software adopts C+ + Accelerated Massive Parallelism (C+ + AMP) so that it runs on GPUs from various hardware vendors including NVidia, AMD and Intel. At large simulation scales, up to two orders of magnitude of speedup factor is observed, compared to CPU-based micromagnetic simulation software OOMMF. The software can run on high-end professional GPUs as well as budget personal laptops, and is free to download.
Developmental programming: a new frontier for the poultry industry?
Authors: Hynd P. I. , Weaver S. , Edwards N. M. , Heberle N. D. , Bowling M.
Published: February 2016

Increasing evidence that the maternal environment influences the programming of developing embryos and fetuses through epigenetic mechanisms has significant potential application in the broiler industry. The broiler breeder hen is subjected to restricted-feeding regimes to maximise egg quantity and quality, but the genetically high-intake potential of these birds makes this regime a stressful one. We propose that this stress is signalled to the developing embryo via changes in yolk composition as an evolutionary adaptation to changing environments, and that exposure to high levels of corticosteroids in ovo is associated with developmental reprogramming, which has effects on the behaviour, health and growth of the progeny. The present paper describes some preliminary results from a series of trials designed to elucidate the relationship between breeder hen diet and egg composition, and the growth, behaviour and immune function of the progeny. We conclude that manipulation of the breeder hen diet is an untapped opportunity to maintain the competitiveness of the chicken meat industry and further, that achieving improved productivity by this means may be compatible with improved animal welfare outcomes for the hen and her progeny.
Liveweight gain and urinary nitrogen excretion of dairy heifers grazing perennial ryegrass-white clover pasture, canola, and wheat
Authors: Cheng L. , McCormick J. , Logan C. , Hague H. , Hodge M. C. , Edwards G. R.
Published: February 2016

This study was carried out to examine liveweight gain (LWG), urinary nitrogen (N) concentration, and urinary N excretion of dairy heifers grazing perennial ryegrass-white clover pasture, dual-purpose wheat and dual-purpose canola. A temporal replicate design with two replicates was used to conduct the study. A total of 24–30 Friesian × Jersey heifers, aged 9–11 months were allocated into three dietary treatment groups (pasture, canola, and wheat) according to their initial LW (184 ± 7.0 kg; mean ± s.d.) and breeding worth (NZ$142 ± 11.3; mean ± s.d.). Feed was allocated every 4 days with allowance calculated according to feed requirement for maintenance plus 0.8 kg LWG/day. The LWG over the 26–28-day experimental period was higher (P < 0.001) for heifers grazing wheat (0.66 kg/day) and canola (0.53 kg/day) than pasture (0.35 kg/day). After the experimental period, heifers were grazed together in one herd on pasture. The LWG over the 28–44-day carryover period was higher (P < 0.001) in canola (0.86 kg/day) than wheat (0.57 kg/day) and pasture (0.61 kg/day). The concentration of urinary N was lower (P = 0.017) in canola (0.21%) and wheat (0.24%) than pasture (0.35%). Estimated urinary N excretion was lower (P < 0.001) in canola (52.5 g/day) and wheat (59.1 g/day) than pasture (98.9 g/day). Data suggest that grazing canola and wheat compared with pasture may improve heifer LWG and potentially reduce N losses to the environment by reducing the N loading of urine patches.
Cross-talk between Arg methylation and Ser phosphorylation modulates apoptosis signal–regulating kinase 1 activation in endothelial cells
Authors: Chen Ming , Qu Xiaosheng , Zhang Zhiqing , Wu Huayu , Qin Xia , Li Fuji , Liu Zhenfang , Tian Liyuan , Miao Jianhua , Shu Wei
Published: February 2016

We describe a novel functional interaction between ASK1 and PRMT5. We show that PRMT5 interacts with and methylates ASK1 at arginine residue 89 and thereby negatively regulates its activity by promoting the interaction between ASK1 and Akt and thus phosphorylating ASK1 at serine residue 83. Furthermore, the association between ASK1 and Akt is enhanced by VEGF stimulation, and PRMT5 is required for this association. Moreover, PRMT5-mediated ASK1 methylation impaired the H2O2-induced activity of ASK1, and this inhibitory effect of PRMT5 was abolished by replacement of arginine 89 with Trp or depletion of PRMT5 expression by RNA interference. Together the results demonstrate cross-talk between arginine methylation and serine phosphorylation in ASK1.
The untapped cell biology of neglected tropical diseases
Authors: Sullivan William
Published: February 2016

The World Health Organization lists a constellation of 17 tropical diseases that afflict approximately one in six individuals on the planet and, until recently, few resources have been devoted to the treatment and eradication of those diseases. They are often referred to as the diseases of the “bottom billion,” because they are most prevalent among the poorest individuals in impoverished tropical nations. However, the few studies that have been performed reveal an extraordinary world of molecular and cellular adaptations that facilitate the pathogens’ survival in hosts ranging from insects to humans. A compelling case can be made that even a modest investment toward understanding the basic molecular and cell biology of these neglected pathogens has a high probability of yielding exciting new cellular mechanisms and insights into novel ways of combating these diseases.
The evolution of multi-component visual signals in darters (genus Etheostoma)
Authors: Gumm Jennifer M. , Mendelson Tamra C.
Published: February 2016

As complex traits evolve, each component of the trait may be under different selection pressures and could respond independently to distinct evolutionary forces. We used comparative methods to examine patterns of evolution in multiple components of a complex courtship signal in darters, specifically addressing the question of how nuptial coloration evolves across different areas of the body. Using spectral reflectance, we defined 4 broad color classes present on the body and fins of 17 species of freshwater fishes (genus Etheostoma) and quantified differences in hue within each color class. Ancestral state reconstruction suggests that most color traits were expressed in the most recent common ancestor of sampled species and that differences among species are mostly due to losses in coloration. The evolutionary lability of coloration varied across body regions; we found significant phylogenetic signal for orange color on the body but not for most colors on fins. Finally, patterns of color evolution and hue of the colors were correlated among the two dorsal fins and between the anterior dorsal and anal fins, but not between any of the fins and the body. The observed patterns support the hypothesis that different components of complex signals may be subject to distinct evolutionary pressures, and suggests that the combination of behavioral displays and morphology in communication may have a strong influence on patterns of signal evolution.
Insights into social relationships among female black howler monkeys Alouatta pigra at Palenque National Park, Mexico
Authors: Van BELLE Sarie , Estrada Alejandro , Strier Karen B.
Published: February 2016

We investigated the social relationships among adult females in two multimale-multifemale groups of black howler monkeys Alouatta pigra during a 14-month study in Palenque National Park, Mexico. Based on over 900 focal hours and over 5400 scan samples recording neighboring group members, we found that females very rarely engaged in agonistic interactions and no dominance hierarchy could be discerned. Relationships among resident females were primarily affiliative, but females of one study group spent a higher proportion of time in close proximity and engaged in affiliative interactions with one another at higher rates than females in the other study group. The strength of female relationships increased with the birth of an infant. Although no females immigrated during the study period, the temporary association of three extragroup females with our study groups implies that the social system of black howler monkeys is more dynamic than previously suggested. These findings suggest that female black howler monkeys behave more similarly to female red howler monkeys A. seniculus than to female mantled howler monkeys A. palliata.
A non-invasive study of alopecia in Japanese macaques Macaca fuscata
Authors: Zhang Peng
Published: February 2016

This article provides information on the phenomenon of alopecia in Japanese macaques, Macaca fuscata, in various environments and proposes a 3-step scoring system for a quantitative assessment of hair loss. Results suggest that alopecia is commonly observed in Japanese macaques, with 20.5% of individuals showing head alopecia and 4.7% showing back alopecia across eight study groups. Alopecia was more commonly observed in adult females (30.8% individuals showing head alopecia and 15.3% showing back alopecia) than in other age-sex classes. Seasonal variation of back alopecia was noted, in particular, individuals with patchy back hair were more frequently observed in winter than in summer. Seasonal variation was not observed in head hair. The distribution of alopecia was also different among study groups. The wild population generally had better hair condition than provisioned populations and captive populations. The present study used a non-invasive alopecia scoring system which can be a useful, rapid and non-invasive tool to monitor animal health and well-being at a population level.
Tadpole types of Chinese megophryid frogs (Anura: Megophryidae) and implications for larval evolution
Authors: Li Cheng , Guo Xian-Guang , Wang Yue-Zhao
Published: February 2016

The larval body shapes and oral discs of 30 frog species from the family Megophryidae from China were examined. Using a phylogenetic framework derived from a Bayesian analysis of published mitochondrial cytochrome b and 16S rRNA gene sequences, we deduced a pattern of historical change among megophryid larval forms. These larvae were categorized into four types according to their body shapes and oral discs: (A) Leptobrachiini type, (B) Lalax type, (C) Brachytarsophrys type, and (D) Megophryini type, of which B and C are novel types. Type A is characterized by a typical oral disc with multiple rows of teeth, representing the tadpole type of the most recent common ancestor of the family Megophryidae. Type B has a typical oral disc with reduced tooth rows, an elongated labium, and integumentary glands. Type C has no labial teeth and a smaller umbelliform oral disc. Type D is characterized by a lack of labial teeth, an enlarged umbelliform oral disc, representing the tadpole of the most recent common ancestor of the subfamily Megophryinae. Our analysis supports the hypothesis that the umbelliform oral disc is apomorphic and also reveals the close association between morphology and microhabitat.
Pointing gesture in a bird- merely instrumental or a cognitively complex behavior?
Authors: Kaplan Gisela
Published: February 2016

Gestures, particularly pointing, are regarded as important pre-speech acts. Intentional and referential pointing has been shown previously in humans and apes but not in songbirds, although some avian species show cognitive abilities rivaling those of apes, and their brain structures and functions show putative preconditions for referential gestural signaling (i.e. mirror neurons, links of vocal learning nuclei to discrete brain areas active during limb and body movements). The results reported are based on trials testing predator detection and responses to a taxidermic model of a wedge-tailed eagle by Australian magpies Gymnorhina tibicen. Magpies were subjected to three conditions of finding this model in their territory (open, sheltered and hidden). In the sheltered and hidden conditions, the discoverer simultaneously engaged in alarm calls and beak pointing, a behavior that has not been described previously. Other group members at once assembled and, after watching the first bird, adopted the same posture by pointing to the location of the intruder. The question is whether beak and body movements orienting towards important stimuli or events are instances of arousal, imitation or intentional communication. The latter presupposes that onlookers interpret the signal and respond by altering their own behavior appropriate to the original stimulus and not merely by imitating the first signaler. Evidence presented here indicates that the act of pointing may well be a complex cognitive behavior, i.e., an intentional and referential signal, showing that pointing is not limited to having hands and arms.
Toward a neurobiology of auditory object perception: What can we learn from the songbird forebrain?
Authors: Lu Kai , Vicario David S.
Published: February 2016

In the acoustic world, no sounds occur entirely in isolation; they always reach the ears in combination with other sounds. How any given sound is discriminated and perceived as an independent auditory object is a challenging question in neuroscience. Although our knowledge of neural processing in the auditory pathway has expanded over the years, no good theory exists to explain how perception of auditory objects is achieved. A growing body of evidence suggests that the selectivity of neurons in the auditory forebrain is under dynamic modulation, and this plasticity may contribute to auditory object perception. We propose that stimulus-specific adaptation in the auditory forebrain of the songbird (and perhaps in other systems) may play an important role in modulating sensitivity in a way that aids discrimination, and thus can potentially contribute to auditory object perception.
Aversive and non-reward learning in the fire-bellied toad using familiar and unfamiliar prey stimuli
Authors: Dicke Ursula , Heidorn Antje , Roth Gerhard
Published: February 2016

The present study investigated how snapping behavior toward familiar and unfamiliar prey is modified by reward omission and aversive conditioning in the fire-bellied toad Bombina orientalis. Toads were trained to snap at cricket images by rewarding them with live crickets. The task was learned, and the learning criterion (10 snapping responses within 2 minutes) was reached in all individuals investigated. Subsequent reward omission did not alter the frequency of snapping to the familiar cricket stimulus. Snapping decreased only in some individuals, when a mild foot shock was applied at snapping. However, at presentation of images of hitherto unfamiliar meal worms and foot-shock application at snapping to the stimulus, the majority of toads diminished snapping significantly. Snapping responses decreased more rapidly, when snapping at meal worms was not rewarded or a footshock was applied uncorrelated to the presentation of or snapping at meal worms. These results demonstrate that in toads familiarity and unfamiliarity of prey stimuli are important factors in aversive learning, because well-trained responses to familiar stimuli become immune against reward omission. Furthermore, at presentation of unfamiliar stimuli, omission of reward and uncorrelated footshock had a stronger aversive effect than correlated footshock.
Competition for shelter between four invasive gobiids and two native benthic fish species
Authors: Kessel N. Van , Dorenbosch M. , Boer M.R.M. De , Leuven R.S.E.W. , Velde G. Van Der
Published: February 2016

Recent invasions by non-native gobiid fish species that are ongoing in the Western European rivers Rhine and Meuse, will lead to interactions with native benthic fish species. Since both non-native gobiids and native benthic species are bottom dwelling species with a preference for shelter during at least part of their life cycle, it is likely that competition for shelter will occur between these non-native and native species when shelter is a limiting factor. To investigate the importance of this mechanism for species replacements, various habitat choice experiments were conducted between two common native benthic fish species (Cottus perifretum and Barbatula barbatula) and four invasive non-native gobiid species (Proterorhinus semilunaris, Neogobius melanostomus, N. kessleri and N. fluviatilis). The first series of single specimen experiments determined the habitat choice of each individual fish species. In a second series of competition experiments, shifts in habitat choice in comparison with the previously observed habitat choice, were determined when a native benthic fish species co-occurred with non-native gobiid species. Native C. perifretum displayed a significant shift in habitat choice in co-occurrence with the gobiids N. kessleri or P. semilunaris. C. perifretum was outcompeted and moved from the available shelter place to less preferred habitat types. During the competition experiments no change in habitat choice of B. barbatula was shown. Our study therefore suggests that competition for shelter is likely to occur in rivers invaded by N. kessleri and P. semilunaris at sites where shelter is limiting.
Potential effects of climate change on a marine invasion: The importance of current context
Authors: Côté Isabelle M. , Green Stephanie J.
Published: February 2016

Species invasions threaten marine biodiversity globally. There is a concern that climate change is exacerbating this problem. Here, we examined some of the potential effects of warming water temperatures on the invasion of Western Atlantic habitats by a marine predator, the Indo-Pacific lionfish (Pterois volitans and P. miles). We focussed on two temperature-dependent aspects of lionfish life-history and behaviour: pelagic larval duration, because of its link to dispersal potential, and prey consumption rate, because it is an important determinant of the impacts of lionfish on native prey. Using models derived from fundamental metabolic theory, we predict that the length of time spent by lionfish in the plankton in early life should decrease with warming temperatures, with a concomitant reduction in potential dispersal distance. Although the uncertainty around change in dispersal distances is large, predicted reductions are, on average, more than an order of magnitude smaller than the current rate of range expansion of lionfish in the Caribbean. Nevertheless, because shorter pelagic larval duration has the potential to increase local retention of larvae, local lionfish management will become increasingly important under projected climate change. Increasing temperature is also expected to worsen the current imbalance between rates of prey consumption by lionfish and biomass production by their prey, leading to a heightened decline in native reef fish biomass. However, the magnitude of climate-induced decline is predicted to be minor compared to the effect of current rates of lionfish population increases (and hence overall prey consumption rates) on invaded reefs. Placing the predicted effects of climate change in the current context thus reveals that, at least for the lionfish invasion, the threat is clear and present, rather than future.
Hitchhiker’s guide to genetic diversity in socially structured populations
Authors: Premo L. S.
Published: February 2016

When selection increases the frequency of a beneficial gene substitution it can also increase the frequencies of linked neutral alleles through a process called genetic hitchhiking. A model built to investigate reduced genetic diversity in Pleistocene hominins shows that genetic hitchhiking can have a strong effect on neutral diversity in the presence of culturally mediated migration. Under conditions in which genetic and cultural variants are transmitted symmetrically, neutral genes may also hitchhike to higher frequencies on the coattails of adaptive cultural traits through a process called cultural hitchhiking. Cultural hitchhiking has been proposed to explain why some species of matrilineal whales display relatively low levels of mitochondrial DNA diversity, and it may be applicable to humans as well. This paper provides a critical review of recent models of both types of hitchhiking in socially structured populations. The models’ assumptions and predictions are compared and discussed in the hope that studies of reduced genetic diversity in humans might improve our understanding of reduced genetic diversity in other species, and vice versa [Current Zoology 58 (1): 287–297, 2012].
Heterospecific interactions and the proliferation of sexually dimorphic traits
Authors: Pfennig Karin S. , Hurlbert Allen H.
Published: February 2016

Sexual selection is expected to promote speciation by fostering the evolution of sexual traits that minimize reproductive interactions among existing or incipient species. In species that compete for access to, or attention of, females, sexual selection fosters more elaborate traits in males compared to females. If these traits also minimize reproductive interactions with het-erospecifics, then species with enhanced risk of interactions between species might display greater numbers of these sexually dimorphic characters. We tested this prediction in eight families of North American birds. In particular, we evaluated whether the number of sexually dimorphic traits was positively associated with species richness at a given site or with degree of sympatry with congeners. We found no strong evidence of enhanced sexual dimorphism with increasing confamilial species richness at a given site. We also found no overall relationship between the number of sexually dimorphic traits and overlap with congeners across these eight families. However, we found patterns consistent with our prediction within Anatidae (ducks, geese and swans) and, to a lesser degree, Parulidae (New World warblers). Our results suggest that sexually selected plumage traits in these groups potentially play a role in reproductive isolation.
Sexual selection on color and behavior within and between cichlid populations: Implications for speciation
Authors: Pauers Michael J. , Mckinnon Jeffrey S.
Published: February 2016

Sexual selection is widely viewed as playing a central role in haplochromine cichlid speciation. Hypothetically, once divergent mate preferences evolve among populations of these fishes, reproductive isolation follows and the populations begin to behave as different species. Various studies have examined patterns of assortative mating among species and sometimes populations, but few have examined variation in directional preferences, especially among populations of the same species. We investigated mate choice behavior in two populations of Labeotropheus fuelleborni, a Lake Malawi endemic. We test whether mating preferences between populations are based on the same traits and in the same direction as preferences within populations. We examine the potential contributions of two classes of trait, color patterns and behaviors, to reproductive isolation. When females chose between either two males of their own population, or two from another, female preferences were generally similar (for the female population) across the two contexts. Mate choice patterns differed between (female) populations for a measure of color, but only modestly for male behavior. In a separate experiment we simultaneously offered females a male of their own population and a male from a different population. In these trials, females consistently preferred males from their own population, which were also the males that displayed more frequently than their opponents, but not necessarily those with color traits suggested to be most attractive in the previous experiment. Thus directional preferences for chroma and related aspects of color may be important when females are presented with males of otherwise similar phenotypes, but may play little role in mediating assortative mating among populations with substantially different color patterns. A preference for male behavior could play some role in speciation if males preferentially court same-population females, as we have observed for the populations studied herein.
Enough dogma: Seeking the middle ground on the role of dingoes
Authors: Glen A. S.
Published: February 2016

Numerous recent studies present evidence that Australian dingoes Canis lupus dingo can benefit native biodiversity by suppressing mesopredators and large herbivores. Allen and colleagues have challenged the reliability of this evidence. Although they make some valid criticisms, I question some of their assertions. While the existing evidence is inconclusive, I argue that to dismiss it completely would be just as dangerous as to embrace it uncritically. I aim to establish a middle ground.
Ontogenetic mechanisms underlying sexual size dimorphism in Urodele amphibians: An across-species approach
Authors: Zhang Lixia , Lu Xin
Published: February 2016

Why do two sexes of the same species differ in body size holds a long-standing question of evolutionary biology. While many across-species comparisons have focused on ultimate causes behind sexual size dimorphism (SSD), only have a few been directed toward elucidating its ontogenetic basis. Urodeles are an amphibian group in which the direction and degree of SSD vary greatly among species. Using demographic data yielded by skeletochronology for 33 urodele species, the current study reveals a positive across-species correlation between SSD and the sex difference in mean age of adult animals, and the latter increases with the corresponding difference in age at maturity; annual growth rate does not differ between the sexes. We conclude that extended longevities in one sex, which is mediated by delayed maturation, would allow it to grow for longer and get larger, with growth rate making a weak contribution to body size. The sex-specific divergence in ontogenetic trajectory might be explained by potentially high growth costs of reproduction to females in association with stronger fecundity selection, and to males that are expected to experience stronger sexual selection.
A test of genetic association among male nuptial coloration, female mating preference, and male aggression bias within a polymorphic population of cichlid fish
Authors: Sluijs Inke van der , Dijkstra Peter D. , Lindeyer Charlotte M. , Visser Bertanne , Smith Alan M. , Groothuis Ton G. G. , Alphen Jacques J. M. van , Seehausen Ole
Published: February 2016

Both interand intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits. Simultaneous disruptive selection by female mate choice and male-male competition can, in theory, lead to speciation without geographical isolation if both act on the same male trait. Female mate choice can generate discontinuities in gene flow, while male-male competition can generate negative frequency-dependent selection stabilizing the male trait polymorphism. Speciation may be facilitated when mating preference and/or aggression bias are physically linked to the trait they operate on. We tested for genetic associations among female mating preference, male aggression bias and male coloration in the Lake Victoria cichlid Pundamilia. We crossed females from a phenotypically variable population with males from both extreme ends of the phenotype distribution in the same population (blue or red). Male offspring of a red sire were significantly redder than males of a blue sire, indicating that intra-population variation in male coloration is heritable. We tested mating preferences of female offspring and aggression biases of male offspring using binary choice tests. There was no evidence for associations at the family level between female mating preferences and coloration of sires, but dam identity had a significant effect on female mate preference. Sons of the red sire directed significantly more aggression to red than blue males, whereas sons of the blue sire did not show any bias. There was a positive correlation among individuals between male aggression bias and body coloration, possibly due to pleiotropy or physical linkage, which could facilitate the maintenance of color polymorphism.
Do females influence paternal responsiveness in male prairie voles Microtus ochrogaster by increasing the salience of infant odors?
Authors: Lang YAMOAH Damaris-Lois , Laryea Wilhemina , Fassil Fiker , Bamshad Maryam
Published: February 2016

Male prairie voles become more responsive to infants following cohabitation with a female. Exposure to female sensory cues prior to offspring birth may influence male paternal tendencies by modifying his response to infant odors in particular or to odors in general. To test these hypotheses, males were housed with an unfamiliar female or a same-sex sibling for 13 days then examined for their response towards either live infants or infant-like inanimate objects covered with one of three odors: water, infant, sub-adult. We recorded the number of males that retrieved and manipulated the infants or odor-covered objects and measured the frequency and duration of time males spent attending to them or engaged in other non-social activities. Female-Cohabited males approached the container holding infant-odor covered objects faster than Male-Cohabited males, but showed no differences in time spent manipulating those objects. Males in both groups spent more time manipulating live infants than odor-covered objects. However, Female-Cohabited subjects were more likely to manipulate odor-covered objects as well as live infants than Male-Cohabited subjects. Additionally, the frequency of self-grooming in Female-Cohabited males was higher for water-covered objects compared to Male-Cohabited males. In presence of water and live infants, Female-Cohabited males groomed themselves with greater frequency than in presence of infant odor or sub-adult odor. The data suggest that female cues increase the male’s sensitivity to infant odors and enhance the salience of non-social odors.
Premigratory fat metabolism in hummingbirds: A Rumsfeldian approach
Authors: Suarez Raul K.
Published: February 2016

Hummingbird migration is a remarkable feat, given the small body sizes of migratory species, their high metabolic rates during flight and the long distances traveled using fat to fuel the effort. Equally remarkable is the ability of premigratory hummingbirds in the wild to accumulate fat, synthesized from sugar, at rates as high as 10% of body mass per day. This paper summarizes, using Rumsfeldian terminology, “known knowns” concerning the energetics of hummingbird migration and premigratory fattening. Energy metabolism during hover-feeding on floral nectar is fueled directly by dietary sugar through the pathway recently named the “sugar oxidation cascade”. However, flight without feeding for more than a few minutes requires shifting to fat as a fuel. It is proposed that behavior and metabolic fuel choice are coadapted to maximize the rate of fat deposition during premigratory fattening. The hummingbird liver appears to possess extraordinarily high capacities for fatty acid synthesis. The analysis of “known knowns” leads to identification of “known unknowns”, e.g., the fates of dietary glucose and fructose, the regulation of fat metabolism and metabolic interactions between liver and adipose tissue. The history of science behooves recognition of “unknown unknowns” that, when discovered serendipitously, might shed new light on fundamental mechanisms as well as human pathological conditions.
Short-term captivity influences maximal cold-induced metabolic rates and their repeatability in summer-acclimatized American goldfinches Spinus tristis
Authors: Swanson David L. , King Marisa O.
Published: February 2016

Studies of metabolic variation in birds have involved both wild and captive individuals, but few studies have investigated whether captivity directly influences metabolic rates, despite such variation potentially confounding conclusions regarding how metabolic rates respond to the conditions under study. In addition, whether short-term captivity influences metabolic rate repeatability in birds is currently uninvestigated. In this study, we measured Msum (maximal cold-induced metabolic rates) in summer acclimatized American goldfinches Spinus tristis directly after capture from wild populations, after approximately 2 weeks of indoor captivity (Captive 1), and again after an additional 1–2 weeks of captivity (Captive 2). Msum increased significantly (16.9%) following the initial captive period, but remained stable thereafter. Body mass (Mb) also increased significantly (9.2%) during the initial captive period but remained stable thereafter, suggesting that muscle growth and/or remodeling of body composition produced the observed metabolic variation. Mb and Msum were not significantly repeatable between wild and Captive 1 birds, but were significantly repeatable between Captive 1 and Captive 2 groups. These data suggest that caution must be exercised when extrapolating metabolic rates from short-term captive to wild populations. In addition, Msum was a repeatable trait for birds under conditions where mean metabolic rates remained stable, but Msum repeatability disappeared during acclimation to conditions promoting phenotypically flexible metabolic responses. This suggests that the capacity for phenotypic flexibility varies among individuals, and such variation could have fitness consequences.
Biotic element analysis of reptiles of China: A test of vicariance model
Authors: Chen Youhua
Published: February 2016

In this contribution, I identify possible biotic elements of reptiles of China using biotic element analysis. I test whether the vicariance model could significantly shape reptilian current distribution patterns. My results show that dispersal is prevailing for reptiles in China. There are four major biotic elements in reptilian distribution, which are East Xizang, Yunnan-Guizhou Plateau, Taiwan and Hainan, respectively. The test of distributional areas is significantly more clustered than expected by chance, while in another test that closely related species are homogeneously distributed across biotic elements cannot be rejected. Therefore I argued that vicariance might be one of the key processes in patterning reptilian distribution in China. In addition, I develop an improved biotic element analysis in biogeographic studies, by performing biotic element analysis in an iterative manner in order to diagnose more geographically restricted elements until no noise components found. The importance of antecedent selection of distributional data for the subsequent analysis is also discussed. Besides, my study indicates that biodiversity hotspots are not fully overlapped with areas of endemism for reptilians in East Asia.
Does defensive posture increase mimetic fidelity of caterpillars with eyespots to their putative snake models?
Authors: Hossie Thomas John , Sherratt Thomas N.
Published: February 2016

Organisms often evolve behaviours that increase or reinforce the protection from predators afforded by their morphological defences. For example, mimetic animals may adopt postures or locomotory behaviours that emulate a characteristic feature of their model to increase predator deception. Caterpillars with eyespots are thought to mimic snakes, and when threatened many of these caterpillars adopt a posture that appears to enhance this resemblance. Herein we evaluate the quantitative strength of evidence of behavioural mimicry in the caterpillars of 14 species by comparing how closely a series of putative snake-mimicking caterpillars resemble snakes while at rest and when threatened. Specifically, we quantified the head morphology and eye position of a range of snake species, as well as the shape of the apparent head (i.e. anterior body segments) and position of eyespots in caterpillars resting or in their defensive posture. This allowed us to objectively examine evidence for an increased resemblance to either snakes generally, or to Viperidae snakes specifically, upon adopting the defensive posture. Widening the anterior body segments during the defensive posture typically made caterpillars appear more viper-like as opposed to more snake-like in general. Enhanced resemblance to vipers upon mounting the defensive posture was apparent only from the dorsal view. Laterally, caterpillars more closely resembled snakes in the resting posture and shifting to the defensive posture instead reduced mimetic fidelity. Overall we found evidence for behavioural mimicry in all 14 species examined. We highlight that objectively quantifying mimetic fidelity can help identify key features involved in deception.
Climate change and contrasting plasticity in timing of a two-step migration episode of an Arctic-nesting avian herbivore
Authors: Fox Anthony David , Weegman Mitch D. , Bearhop Stuart , Hilton Geoff M. , Griffin Larry , Stroud David A. , Walsh Alyn
Published: February 2016

Greenland white-fronted geese Anser albifrons flavirostris wintering in Britain and Ireland migrate over the sea for 700–1200 km to stage 3–5 weeks in Iceland in spring, continuing a similar distance over the sea and Greenland Ice Cap to West Greenland breeding grounds. During 1969 to 2012, the geese advanced the mean departure date from Ireland by 15 days, during which time also they attained threshold fat stores earlier as well as departing in fatter condition. Over that period, Iceland spring-staging geese shifted from consuming underground plant storage organs to grazing managed hayfields, which provide fresh grass growth despite sub-zero temperatures, when traditional natural foods are inaccessible in frozen substrates. In 2012 and 2013, geese arrived three weeks earlier to Iceland, in fatter condition and accumulated fat significantly slower than in 1997–1999 and 2007. Although geese accumulated sufficient fat stores earlier in Iceland in 2007, 2012 and 2013, they departed around the same date as in 1997–1999, prolonging spring staging by three weeks. Plasticity in winter departure dates is likely due to improved winter feeding conditions (enabling earlier departure in better condition) and a novel predictable food resource in Iceland. Greenland white-fronted geese attained threshold fat stores in Iceland earlier, but remained rather than departing earlier to Greenland. Despite arriving earlier in Iceland, arrival dates on the breeding areas have not changed since the 1880s, presumably because of relatively constant cool springs and heavy snowfall in West Greenland during recent years.
Animal personality and the ecological impacts of freshwater non-native species
Authors: Juette Tristan , Cucherousset Julien , Cote Julien
Published: February 2016

While the ecological impacts of invasive species have been demonstrated for many taxonomic groups, the potential effects of behavioural variation among non-native individuals (i.e. personality) on these impacts have been largely overlooked. This is despite the fact that recent studies have demonstrated that, by nature, the three first stages of biological invasions (i.e. transport, establishment and spread) can lead to personality-biased populations. Freshwater ecosystems provide a unique opportunity to investigate this issue, notably because the ecological impacts of non-native species have been extensively documented and because animal personality has been widely studied using freshwater model species. Here, we aim at developing some perspectives on the potential effects of animal personality on the ecological impacts of freshwater non-native species across levels of biological organizations. At the individual level, personality types have been demonstrated to affect the physiolo- gy, metabolism, life history traits and fitness of individuals. We used these effects to discuss how they could subsequently impact invaded populations and, in turn, recipient communities. We also discussed how these might translate into changes in the structure of food webs and the functioning of invaded ecosystems. Finally we discussed how these perspectives could interact with the management of invasive species.
Woodland Mediterranean birds can resist a dry extreme cold wave
Authors: VilléN-Pérez Sara , Carrascal Luis M.
Published: February 2016

The ecological consequences of climate extreme events are still poorly understood, especially those related to cold episodes. Winter cold spells might imperil the energy balance of small passerines, thus compromising their survivorship. Here we analyze how the abundance and habitat use of three tree-gleaning passerine species wintering in a montane oakwood of central Spain at ca. 1,300 m a.s.l. was influenced by the cold wave that hit Europe in February 2012. We monitored temperature, wind and the relative abundance of great tit Parus major, blue tit Cyanistes caeruleus and long-tailed tit Aegithalos caudatus in 15 plots throughout three periods: before, during and after the cold wave. Our results clearly rule out widespread mortality and temporal migration of the studied passerine populations, as the abundance of these species did not diminish during the cold wave. Moreover, the species usually foraging higher in the tree canopy -and thus more exposed to wind-moved to the less windy woodland plots (long-tailed tit) and reduced their foraging height above ground during the cold wave (long-tailed tit and blue tit), probably to mitigate the deleterious effects of wind chill. Therefore, these forest birds were able to cope with a dry cold wave that was statistically extreme in terms of temperature and wind chill, according to the historic climate records of the region. It seems that, at least when foraging substrates are not heavily covered by snow or ice, Mediterranean birds can resist an extreme cold wave [Current Zoology 60 (4): 429–437, 2014].
Using the movement patterns of reintroduced animals to improve reintroduction success
Authors: Berger-TAL Oded , Saltz David
Published: February 2016

Despite their importance to conservation, reintroductions are still a risky endeavor and tend to fail, highlighting the need for more efficient post-release monitoring techniques. Reintroduced animals are released into unfamiliar novel environments and must explore their surroundings to gain knowledge in order to survive. According to theory, knowledge gain should be followed by subsequent changes to the animal’s movement behavior, making movement behavior an excellent indicator of reintroduction progress. We aim to conceptually describe a logical process that will enable the inclusion of behavior (in particular, movement behavior) in management decision-making post-reintroductions, and to do so, we provide four basic components that a manager should look for in the behaviors of released animals. The suggested components are release-site fidelity, recurring locations, proximity to other individuals, and individual variation in movement behavior. These components are by no means the only possible ones available to a manager, but they provide an efficient tool to understanding animals’ decision-making based on ecological theory; namely, the exploration-exploitation trade-off that released animals go through, and which underlies their behavior. We demonstrate our conceptual approach using data from two ungulate species reintroduced in Israel: the Persian fallow deer Dama mesopotamica and the Arabian oryx Oryx leucoryx [Current Zoology 60 (4): 515–526, 2014].
Time to feed: How diet, competition, and experience may influence feeding behaviour and cannibalism in wood frog tadpoles Lithobates sylvaticus
Authors: Jefferson Dale M. , Hobson Keith A. , Chivers Douglas P.
Published: February 2016

Wood frog Lithobates sylvaticus tadpoles develop in temporary wetlands where high population densities can force tadpoles into aggregations that intensify competition and can lead to cannibalism. However, chemical alarm cues released from injured conspecifics could also dissuade cannibalism. The purpose of this study was to test mechanisms that may influence cannibalistic behaviour. We tested whether the tendency of tadpoles to consume conspecifics would increase with the presence of competition and/or cues of profitable diets. Tadpoles placed in 1L experimental containers were tested for feeding initiation times of multiple diets, including conspecific tissues and conspecific tissues combined with chemical cues from the alternative diets (brine shrimp and cornmeal). Tadpoles were tested in the presence and absence of a competitor, and at multiple times over the course of the study. Tadpoles exhibited an altered response to diets over time; however the presence of a competitor reduced response times to all diets including conspecific tissues. Similarly, the presence of specific diets also reduced the response time of tadpoles to conspecific tissues. These results suggest competition among feeding tadpoles could result in aggressive behaviour leading to indiscriminate predation and cannibalism.