bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of rare species on natural assemblages
Authors: GRAY JOHN S. , BJØRGESÆTER ANDERS , UGLAND KARL I. 
Published: October 2005

SummaryCompared with most terrestrial data sets used in development of theoretical models, what characterizes data sets from marine soft sediments is that they have a very high number of species. Marine data also show large numbers of rare species, even if the extent of the study is greatly increased from a few square metres to hundreds of square kilometres.Fitting log‐normal distributions to data on species abundance distributions (SADs) for marine benthic assemblages from the continental shelf of Norway, and for the well‐studied tropical tree data of Barro Colorado Island, Panama (BCI), show patterns suggesting that more than one log‐normal distribution occurs.We have developed a simple model of SADs comprising two groups of log‐normally distributed species, a group of rare species and a group of common species. The model appears to fit the marine data and also applies to the BCI tropical tree data and yet is simpler than Hubbell's Zero‐Sum Multinomial (ZSM) distribution model.The plots of the model results show that the marine data are dominated by the rare group of species at all scales studied. In the tropical tree assemblage a similar pattern to that in the marine data is apparent only at small spatial scales (5 and 10 ha), but not at the larger extent (25–50 ha). It is important to note, however, that marine data at all the scales studied are samples from a given area, whereas the terrestrial data are exact counts of all species of tree within the total 50 ha plot studied.Most ecological data are likely to be based on samples rather than exact counts so the patterns found with the marine data are likely to be common, and our findings general ones.A biological explanation for the two‐group log‐normal model is that recruitment of rare species from outside the studied area dominates benthic assemblages of soft sediments at all sampled scales. Within the tropical forest the dominance of recruitment processes are only apparent at small scales.Thus, the interpretation of SAD patterns depends greatly on the type of data collected, i.e. whether they are exact counts or samples. We believe that structuring processes are similar in marine and many terrestrial systems and these processes probably conform to the mass‐effects paradigm of the newly termed meta‐community concept.
Genetic and spatial structure within a swift fox population
Authors: KITCHEN ANN M. , GESE ERIC M. , WAITS LISETTE P. , KARKI SEIJA M. , SCHAUSTER EDWARD R. 
Published: October 2005

Summary

We incorporated spatial data on swift foxes (Vulpes velox) with genetic analysis to assess the influence of relatedness between individuals on their social and spatial ecology. We recorded the space use patterns of 188 radio‐collared swift foxes in south‐eastern Colorado from January 1997 to December 2000. One hundred and sixty‐seven foxes were also genotyped at 11 microsatellite DNA loci and the degree of relatedness between individuals was estimated.
We described the genetic structure of the population by examining the relatedness of neighbours and the relationship between the spatial and genetic distance of all individuals. We found that close kin appeared to cluster within the population. Neighbours were significantly more related (mean R = 0·089 ± 0·01) than non‐neighbours (mean R = 0·003 ± 0·01; randomization test, P < 0·0002). Female clusters were more extensive than male clusters.
The degree of genetic relatedness among foxes was useful in explaining why foxes tolerated encroachment of their home ranges by neighbours; the more closely related neighbours were, the more home‐range overlap they tolerated (Mantel test, P = 0·0004). Foxes did not appear to orientate their home ranges to avoid neighbours and home ranges overlapped by as much as 54·77% (x = 14·13% ± 0·41). Neighbours also occasionally engaged in concurrent den sharing.
Relatedness influenced the likelihood that an individual would inherit a newly vacated home range, with a mean relatedness of range inheritors to previous owners of 0·333 ± 0·074. Thus, the genetic structure of the population and interactions between kin were interrelated to space‐use patterns and social ecology of the swift fox.
Factors affecting susceptibility of farms to crop raiding by African elephants: using a predictive model to mitigate conflict
Authors: SITATI N. W. , WALPOLE M. J. , LEADER‐WILLIAMS N. 
Published: October 2005

SummaryCrop raiding by African elephantsLoxodonta africanaerodes local tolerance for elephants and thereby impedes conservation efforts, so solutions are urgently required. Within conflict zones, crop raiding is not distributed equally amongst farms, which may be a result of variation in local physical or geographical factors, or in farmers’ efforts to defend their fields. Understanding the efficacy of local conflict mitigation methods is important, but few quantitative evaluations exist.Using a comparative survey of raided and non‐raided farms in Transmara District, Kenya, and multivariate logistic and linear regression analyses, we explored a range of factors affecting (i) the susceptibility of farms to elephant crop raiding and (ii) the amount of crop damage once elephants had entered a field.The results revealed that farms that had been habitually raided in the past were more likely to be raided during the study period, as were those that were larger and bordered by hedges or fences. Greater guarding effort increased the likelihood that elephants were detected prior to entry and decreased the likelihood of successful crop raiding, as did the use of fire and noise.However, there was an interaction between physical and human factors; larger farms used more advanced barrier methods at the expense of guarding effort. Farmers’ efforts did not appear to diminish the damage inflicted once elephants had entered a field.A subsequent experimental test confirmed these results; the application of enhanced early warning and guarding effort on previously raided farms reduced incidents of crop raiding by 89·6% over 2 years in comparison with a control group of farms.Synthesis and applications. These results suggest that early detection of elephants approaching fields, increased guarding effort, and the use of active deterrents could form the basis of an effective mitigation strategy regardless of location and the physical attributes of a farm. Validating the results of predictive models through participatory mitigation trials serves to demonstrate effective solutions to farmers themselves. Researchers and practitioners should be encouraged to replicate such field trials over broader spatial and temporal scales and to find means to encourage farmers to take up appropriate solutions.
Evolution of the Euphrasia transmorrisonensis complex (Orobanchaceae) in alpine areas of Taiwan
Authors: Wu Ming‐Jou , Huang Shing‐Fan , Huang Tseng‐Chieng , Lee Pei‐Fen , Lin Tsan‐Piao 
Published: October 2005

AbstractAims  To unravel isolation and differentiation of the genetic structure of the Euphrasia transmorrisonensis complex, a showy herb, among alpine regions of mountain peaks in subtropical Taiwan and to infer its evolutionary history.Location  Alpine ecosystems of high‐montane regions of Taiwan.Methods  Phylogenetic analyses of the trnL intron and the trnL–trnF intergenic spacer of chloroplast (cp) DNA, and the intertranscribed spacer (ITS) of nuclear ribosomal (nr) DNA between 18S and 26S were carried out on 18 populations of the E. transmorrisonensis complex in Taiwan.Results  In total, 10 haplotypes for cpDNA and 14 haplotypes for nrDNA were detected. Three population groups located in the northern, north‐eastern, and south‐central regions of the Central Mountain Range (CMR) were revealed according to the frequencies of haplotypes and haplotype lineages of nrDNA. Balancing selection might have played a role in the evolution of Euphrasia in Taiwan.Main conclusions  By integrating the spatial‐genetic patterns of cpDNA and nrDNA, two possible evolutionary histories of Euphrasia in Taiwan were inferred. The favourable hypotheses for interpreting the data suggest at least three origins of the E. transmorrisonensis complex in Taiwan, corresponding to each nuclear lineage in the northern (II), northern/north‐eastern (I), and central/southern regions (III) with subsequent hybridization between lineages I and II and lineages II and III. These lineage boundaries are strengthened by the finding that haplotypes of C derived from cpDNA were found in the geographical region of lineage II of nrDNA, while haplotypes of A derived from cpDNA were found in the region of lineage III of nrDNA. Thus, the origin of chloroplasts exclusive to lineages II and III supports their long‐term isolation from one another.
The fauna of Greece and adjacent areas in the Age of Homer: evidence from the first written documents of Greek literature
Authors: Voultsiadou Eleni , Tatolas Apostolos 
Published: October 2005

AbstractAim  To study the composition of fauna in Greece and adjacent areas around 3000 years ago based on the knowledge of Homeric man about the animal kingdom.Location  Greece and adjacent areas.Method  Analysis of information derived from a thorough study of the first written documents of Greek literature, the epics, attributed to Homer and Hesiod.Results  Records of 2442 animals were found, corresponding to 71 different animal names. All animal names were attributed to recent taxa, at different category levels; the majority (65%) were assigned to taxa at the species level and the rest to supraspecific taxa. Most of the animal names recorded in the epics have been retained as integral words or roots in Modern Greek and they have been used in the formation of the Latin scientific taxa names. Five animal phyla appear in the texts: (1) Chordata (mostly birds and mammals), (2) Arthropoda, (3) Mollusca, (4) Porifera, and (5) Annelida. Information in the epics also includes morphology, biology, ecology (habitat and prey–predator relationships), and behaviour. The presence of several species in the area in that period is documented on the basis of archaeological and/or palaeontological findings from various Greek localities.Main conclusions  The knowledge of Homeric man about animals, as reflected in the epics, seems to concentrate mainly, but not exclusively, on animals involved in human activities. The populations of some common animal species of the Homeric Age in Greek populated areas have become extinct or reduced at the present time. On the other hand, some common animals of the present time do not appear in the epics, since they were introduced later. Useful zoological information can be derived from the study of classical texts, which may help historical biogeographers as a supplement to archaeology and art, in the reconstruction of faunas of older periods.
Relationships between local population persistence, local abundance and regional occupancy of species: distribution patterns of diatoms in boreal streams
Authors: Soininen Janne , Heino Jani 
Published: October 2005

AbstractAims  We have two aims: (1) to examine the relationship between local population persistence, local abundance and regional occupancy of stream diatoms and (2) to characterize the form of the species–occupancy frequency distribution of stream diatoms.Location  Boreal streams in Finland. There were three spatial extents: (1) across ecoregions in Finland, (2) within ecoregions in Finland, and (3) within a single drainage system in southern Finland.Methods  Diatoms were sampled from stones (epilithon), sediment (epipelon) and aquatic plants (epiphyton) in streams using standardized sampling methods. To assess population persistence, diatom sampling was conducted monthly at four stream sites from June to October. The relationships between local population persistence, local abundance and regional occupancy were examined using correlation analyses.Results  There was a significant positive relationship between local persistence and abundance of diatoms in epilithon, epipelon and epiphyton. Furthermore, local abundance and regional occupancy showed a significant positive relationship at multiple spatial extents; that is, across ecoregions, within ecoregions and within a drainage system. The relationships between occupancy and abundance did not differ appreciably among impacted and near pristine‐reference sites. The occupancy–frequency distribution was characterized by a large number of satellite species which occurred at only a few sites, whereas core species that occurred at most sites were virtually absent.Main conclusions  The positive relationship between local population persistence and abundance suggested that a high local abundance may prevent local extinction or that high persistence is facilitated by a high local cell density. High local persistence and local abundance may also positively affect the degree of regional occupancy in stream diatoms. The results further showed that anthropogenic effects were probably too weak to bias the relationship between occupancy and abundance, or that the effects have already modified the distribution patterns of stream diatoms. The small number of core species in the species–occupancy frequency distribution suggested that the regional distribution patterns of stream diatoms, or perhaps unicellular microbial organisms in general, may not be fundamentally different from those described previously for multicellular organisms, mainly in terrestrial environments, although average global range sizes may differ sharply between these two broad groups of organisms.
Elevational gradient analyses and the use of historical museum specimens: a cautionary tale
Authors: Rowe Rebecca J. 
Published: October 2005

AbstractAim  The value of biodiversity informatics rests upon the capacity to assess data quality. Yet as these methods have developed, investigating the quality of the underlying specimen data has largely been neglected. Using an exceptionally large, densely sampled specimen data set for non‐flying small mammals of Utah, I evaluate measures of uncertainty associated with georeferenced localities and illustrate the implications of uncritical incorporation of data in the analysis of patterns of species richness and species range overlap along elevational gradients.Location  Utah, USA, with emphasis on the Uinta Mountains.Methods  Employing georeferenced specimen data from the Mammal Networked Information System (MaNIS), I converted estimates of areal uncertainty into elevational uncertainty using a geographic information system (GIS). Examining patterns in both areal and elevational uncertainty measures, I develop criteria for including localities in analyses along elevational gradients. Using the Uinta Mountains as a test case, I then examine patterns in species richness and species range overlap along an elevational gradient, with and without accounting for data quality.Results  Using a GIS, I provide a framework for post‐hoc 3‐dimensional georeferencing and demonstrate collector‐recorded elevations as a valuable technique for detecting potential errors in georeferencing. The criteria established for evaluating data quality when analysing patterns of species richness and species range overlap in the Uinta Mountains test case reduced the number of localities by 44% and the number of associated specimens by 22%. Decreasing the sample size in this manner resulted in the subsequent removal of one species from the analysis. With and without accounting for data quality, the pattern of species richness along the elevational gradient was hump‐shaped with a peak in richness at about mid‐elevation, between 2300 and 2600 m. In contrast, the frequencies of different pair‐wise patterns of elevational range overlap among species differed significantly when data quality was and was not accounted for.Main conclusions  These results indicate that failing to assess spatial error in data quality did not alter the shape of the observed pattern in species richness along the elevational gradient nor the pattern of species’ first and last elevational occurrences. However, it did yield misleading estimates of species richness and community composition within a given elevational interval, as well as patterns of elevational range overlap among species. Patterns of range overlap among species are often used to infer processes underlying species distributions, suggesting that failure to account for data quality may alter interpretations of process as well as perceived patterns of distribution. These results illustrate that evaluating the quality of the underlying specimen data is a necessary component of analyses incorporating biodiversity informatics.
Lentic odonates have larger and more northern ranges than lotic species
Authors: Hof Christian , Brändle Martin , Brandl Roland 
Published: October 2005

AbstractAim We analysed latitudinal range, centres of distribution and northern range boundaries of dragonflies and damselflies occurring in Europe and North America with respect to larval habitat (standing water = lentic and running water = lotic). As lentic water bodies are thought to be less predictable in space and time than lotic habitats, species adapted to standing waters depend on effective dispersal ability for long‐term survival. If species occurring in lentic habitats have a higher propensity for dispersal, then larger range sizes in lentic than in lotic species, as well as an increase in the proportion of lentic species with latitude, would be expected.Location Europe, North America.Methods Distributional and habitat data were collected from published sources for all odonates of Europe and North America. Species were assigned to lentic and lotic habitats according to the habitat of the larvae. From distribution maps we estimated the latitudinal range, centre of distribution and northern range boundary of each species. Differences in these distribution variables between lentic and lotic species were evaluated usinganova. We related the proportion of lentic species by latitudinal interval in Europe, and by political unit (state, province) in North America, to area, altitudinal range, longitude (only for North America) and latitude by means of generalized linear models.Results Lentic damselflies and dragonflies had larger latitudinal spans, and more northern distribution centres and range boundaries, than lotic species. The proportion of lentic species increased with latitude. These findings were consistent between continents.Main conclusions Our results support previous findings that distribution patterns of freshwater species depend on habitat preference. Evolution of dispersal propensity according to habitat characteristics is the most likely explanation. However, at present, alternative explanations, such as an increase in lentic habitats with latitude, cannot be ruled out.
Chronic Intermittent Cold Stress Sensitises the Hypothalamic‐Pituitary‐Adrenal Response to a Novel Acute Stress by Enhancing Noradrenergic Influence in the Rat Paraventricular Nucleus
Authors: Ma S. , Morilak D. A. 
Published: October 2005

AbstractChronic intermittent cold stress sensitises activation of the hypothalamic‐pituitary‐adrenal (HPA) axis by novel acute stress. We have shown that enhanced noradrenergic function in limbic forebrain contributes to HPA sensitisation. In the present study, we investigated whether chronic intermittent cold also induced changes in noradrenergic function in the paraventricular nucleus (PVN), the primary mediator of the HPA stress response. Rats were exposed to chronic intermittent cold (7 days, 6 h per day, 4 °C). On the day after final cold exposure, there were no differences in baseline plasma ACTH, but the peak ACTH response to 30 min of acute immobilisation stress was greater in cold‐stressed rats compared to controls. Bilateral microinjection of the α1‐adrenergic receptor antagonist benoxathian into the PVN reduced acute stress‐induced adrenocorticotrophic hormone (ACTH) levels by approximately 25% in controls. Furthermore, in cold‐stressed rats, all of the sensitisation of the ACTH response was blocked by benoxathian, to a level comparable to benoxathian‐treated controls. In a second study using microdialysis to measure norepinephrine release in the PVN, there were no differences in either baseline or acute stress‐induced increases in norepinephrine release in the PVN of cold‐stressed rats compared to controls. Thus, in a third study, we tested potential alterations in postsynaptic α1‐receptor sensitivity after chronic cold stress. Dose‐dependent activation of ACTH secretion by microinjection of the α1‐adrenergic receptor agonist, phenylephrine, into the PVN was significantly enhanced in cold‐stressed rats compared to controls. Thus, the sensitised HPA response to acute stress after chronic intermittent cold exposure is at least partly attributable to an enhanced response to α1‐adrenergic receptor activation in the PVN. Chronic stress‐induced plasticity in the acute stress response may be important for stress adaptation, but may also contribute to pathophysiological conditions associated with stress. Thus, understanding the neural mechanisms underlying such adaptations may help us understand the aetiology of such disorders, and contribute to the future development of more effective treatment or prevention strategies.
It's good to be queen: classically eusocial colony structure and low worker fitness in an obligately social sweat bee
Authors: RICHARDS MIRIAM H. , FRENCH DEANNA , PAXTON ROBERT J. 
Published: October 2005

AbstractLasioglossum malachurum, a bee species common across much of Europe, is obligately eusocial across its range but exhibits clear geographic variation in demography and social behaviour. This variation suggests that social interactions between queens and workers, opportunities for worker oviposition, and patterns of relatedness among nest mates may vary considerably, both within and among regions. In this study, we used three microsatellite loci with 12–18 alleles each to examine the sociogenetic structure of colonies from a population at Agios Nikolaos Monemvasias in southern Greece. These analyses reveal that the majority of colonies exhibit classical eusocial colony structure in which a single queen mated to a single male monopolizes oviposition. Nevertheless, we also detect low rates of multiqueen nest founding, occasional caste switching by worker‐destined females, and worker oviposition of both gyne and male‐producing eggs in the final brood. Previous evidence that the majority of workers show some ovarian development and a minority (17%) have at least one large oocyte contrasts with the observation that only 2–3% of gynes and males (the so‐called reproductive brood) are produced by workers. An evaluation of the parameters of Hamilton's Rule suggests that queens benefit greatly from the help provided by workers but that workers achieve greater fitness by provisioning and laying their own eggs rather than by tending to the queen's eggs. This conflict of interest between the queen and her workers suggests that the discrepancy between potential and achieved worker oviposition is due to queen interference. Comparison of relatedness and maternity patterns in the Agios Nikolaos Monemvasias population with those from a northern population near Tübingen, Germany, points to a north–south cline of increasingly effective queen control of worker behaviour.