Abstract View

Elliser, C. R. and Herzing, D. L. (2013), Long-term social structure of a resident community of Atlantic spotted dolphins, Stenella Frontalis, in the Bahamas 1991–2002. Marine Mammal Science. doi: 10.1111/mms.12039
Long-term social structure data on small delphinids is lacking for most species except the bottlenose dolphin. This study describes the long-term social structure of one community of Atlantic spotted dolphins, Stenella frontalis, divided into three social clusters. Data from 12 yr were analyzed using SOCPROG 2.3. Coefficients of association (CoA) were calculated using the half-weight index. The overall mean community CoA ranged from 0.09 to 0.12. Temporal analyses and mantel tests revealed significant differences between sex class associations due to high male-male CoA (0.12–0.23) compared to female-female and mixed sex CoA (0.08–0.10). Female associations were strongly influenced by reproductive status, calf care, and social familiarity, but not by age class. Male associations were strongly influenced by age, access to females, and alliance formation. Males showed two levels of alliance formation, long-term first order pairs/trios (CoA 0.70–1.00) and shorter-term second order alliances between two or more first order alliances (CoA 0.45–0.69), and a possible third level during interspecies interactions. Mating strategies, sex, and cluster formation shaped the social structure in this spotted dolphin community. Similar to many bottlenose dolphin studies, long-term affiliations for spotted dolphins were correlated with age, sex, and reproductive status.

Daniela Rodríguez, Ricardo A. Ojeda, Scaling coexistence and assemblage patterns of desert small mammals, Mammalian Biology – Zeitschrift für Säugetierkunde, Available online 29 May 2013, ISSN 1616-5047, 10.1016/j.mambio.2013.04.003.
Scaling biodiversity patterns has been recognized lately as a very important issue in the search of global processes; however coexistence and assemblage patterns are typically approached at a single spatial scale. Here, we examined coexistence and co-occurrence patterns of desert small mammal communities across different spatial scales in the search of general community patterns. We sampled small mammals in Monte desert (Argentina, South America) for small spatial scales and reviewed published papers from other worldwide deserts for large spatial scale analyses. We used classic community estimators (Shannon, Richness), rank abundance curves and fitting distributions to analyze species coexistence and co-occurrence patterns. Assemblage patterns were analyzed evaluating nestedness across spatial scales and among deserts. Worldwide desert small mammal assemblages are characterized mainly by low species richness and high variation in species composition. The central Monte desert of Argentina showed a consistent assemblage pattern across spatial scales, with a generalist species being the most abundant and widely distributed, accompanied by other subordinate and more narrowly distributed species. All Monte desert communities were significantly nested, with nestedness increasing with scale from patch to regional. Assemblage and coexistence patterns were similar when comparing worldwide deserts despite differences in total richness and faunal singularity. The degree of nestedness varied among worldwide deserts; however all of them showed a consistent nested pattern. Differences in the degree of nestedness could be a result of different regulating factors depending on the desert and scale. These results highlight the importance of including multiscale approaches when dealing with processes that structure desert communities.

Esther van der Meer, Jealous Mpofu, Gregory S.A. Rasmussen, Hervé Fritz, Characteristics of African wild dog natal dens selected under different interspecific predation pressures, Mammalian Biology – Zeitschrift für Säugetierkunde, Available online 29 May 2013, ISSN 1616-5047, 10.1016/j.mambio.2013.04.006.
To successfully reproduce, many carnivorous mammals need access to suitable den sites. Den site selection is often based on fitness related criteria like escape from predators, food availability and shelter from extreme weather conditions. African wild dogs are cooperative breeders that use a den to give birth to their offspring. They often co-exist with lions and spotted hyenas, both of which are known to kill African wild dog pups. Little is known about den site selection by African wild dogs. In this study, we compared vegetation characteristics and distribution of roads and waterholes around den sites and random sites, in areas with high and low lion and spotted hyena densities. In both areas, African wild dogs selected den sites in closed woodland with little visibility, which is likely to reduce detection by predators, increase the likelihood of escape when detected, and might provide shelter from extreme weather conditions. In the high predator density area, African wild dogs seemed to spatially avoid predators by selecting den sites in this type of habitat relatively further away from waterholes and roads. African wild dogs have high energetic costs of gestation. Therefore, even when predation risk is relatively low, they are likely to try to maximise their fitness by choosing a den site in habitat that will provide optimal protection for their offspring, leaving little additional options to respond to a higher predation pressure.

Patrícia I. Pedro, Jaime A. Ramos, Verónica C. Neves, Vítor H. Paiva
Past and present trophic position and decadal changes in diet of Yellow-legged Gull in the Azores Archipelago, NE Atlantic
European Journal of Wildlife Research, May 2013

This study evaluates the trophic position of adult Yellow-legged Gulls Larus michahellis atlantis resident in the Azores archipelago in the past (1921–1928) and in the present (2009–2010), and analyses the decadal variation in the diet of breeding birds from the 1990s to the 2000s for three main colonies (Topo Islet, Baixo Islet and Mistério da Prainha). Using mixing models, we compared stable isotope signatures of nitrogen and carbon in adult breast feathers between birds from 1921 to 1928 (held in museum collections) and 2009 to 2010, jointly with both isotopic signatures of their main prey groups (fish, goose barnacles (Lepas anatifera), seabirds, mammals and refuse). The diet of breeding birds was analysed using pellets collected in 1989, 1995, 1996, 2004, 2009 and 2010. Stable isotopes analysis (SIA) results were in accordance with the results provided from the analysis of pellets, showing a relatively recent and significant change in the diet of adult gulls. In particular, SIA revealed a significant decrease in the trophic position of Yellow-legged Gulls in the Azores, over the last 89 years in response to the decrease in the consumption of seabirds and fish and, an increase in the consumption of marine invertebrates (goose barnacles) and refuse. The analysis of pellets confirmed the significant decrease in the fish ingested, whereas the ingestion of lower trophic level prey (i.e. goose barnacles, mammals and refuse) increased. Both methods reflect the feeding plasticity and opportunistic foraging behavior of this species, and are in accordance with patterns described for continental Europe.

Judit Vas, Rachel Chojnacki, Marte Flor Kjøren, Charlotte Lyngwa, Inger Lise Andersen, Social interactions, cortisol and reproductive success of domestic goats (Capra hircus) subjected to different animal densities during pregnancy, Applied Animal Behaviour Science, Available online 29 May 2013, ISSN 0168-1591, 10.1016/j.applanim.2013.04.009.
Although goats in many countries are kept indoors in the winter season, during gestation and kidding, recommendations and regulations regarding available space per goat are highly variable. The effects of different housing conditions on the welfare and behaviour are understudied in this species. The aim of the present study was to observe some behavioural, physical and physiological parameters of pregnant dairy goats kept indoors at different animal densities, and their possible influence on reproduction data was also followed. Pregnant Norwegian dairy goats from early pregnancy until parturition were kept constantly at 1, 2 or 3m2 per animal. Their social behaviour (offensive, defensive, socio-positive), body condition, weight gain and blood cortisol level were monitored throughout pregnancy. Weight and gender of offspring were recorded. We found that goats kept at higher density showed more offensive and defensive behaviours, but there was no difference in socio-positive behaviours between treatments. The increase in agonistic behaviours was not reflected in blood cortisol level, weight gain or production data. We concluded, that higher frequency of agonistic behaviours is present even at 2.0m2 per animal, and if this is regarded as a sign of social stress recommendations regarding available space per goat should be adjusted. However, keeping goats even at 1m2 per animal did not have any impact on productivity or weight development, suggesting that they easily habituate to sub-optimal environmental conditions.

Michael Winklhofer, Evelyn Dylda, Peter Thalau, Wolfgang Wiltschko, and Roswitha Wiltschko
Avian magnetic compass can be tuned to anomalously low magnetic intensities
Proc. R. Soc. B July 22, 2013 280 1763 20130853; doi:10.1098/rspb.2013.0853 1471-2954

The avian magnetic compass works in a fairly narrow functional window around the intensity of the local geomagnetic field, but adjusts to intensities outside this range when birds experience these new intensities for a certain time. In the past, the geomagnetic field has often been much weaker than at present. To find out whether birds can obtain directional information from a weak magnetic field, we studied spontaneous orientation preferences of migratory robins in a 4 µT field (i.e. a field of less than 10 per cent of the local intensity of 47 µT). Birds can adjust to this low intensity: they turned out to be disoriented under 4 µT after a pre-exposure time of 8 h to 4 µT, but were able to orient in this field after a total exposure time of 17 h. This demonstrates a considerable plasticity of the avian magnetic compass. Orientation in the 4 µT field was not affected by local anaesthesia of the upper beak, but was disrupted by a radiofrequency magnetic field of 1.315 MHz, 480 nT, suggesting that a radical-pair mechanism still provides the directional information in the low magnetic field. This is in agreement with the idea that the avian magnetic compass may have developed already in the Mesozoic in the common ancestor of modern birds.

Hélène M. De Nys, Sébastien Calvignac-Spencer, Ursula Thiesen, Christophe Boesch, Roman M. Wittig, Roger Mundry, and Fabian H. Leendertz
Age-related effects on malaria parasite infection in wild chimpanzees
Biol. Lett. August 23, 2013 9 4 20121160; doi:10.1098/rsbl.2012.1160 1744-957X

Wild great apes are widely infected with a number of malaria parasites (Plasmodium spp.). Yet, nothing is known about the biology of these infections in the wild. Using faecal samples collected from wild chimpanzees, we investigated the effect of age on Plasmodium spp. detection rates. The data show a strong association between age and malaria parasite positivity, with significantly lower detection rates in adults. This suggests that, as in humans, individuals reaching adulthood have mounted an effective protective immunity against malaria parasites.

Rauscher, R. L., Story, S. J., Gude, J. A. and Russell, R. E. (2013), Estimation of black-tailed prairie dog colonies in Montana. Wildlife Society Bulletin. doi: 10.1002/wsb.290
Black-tailed prairie dog (Cynomys ludovicianus) is an influential species in prairie ecosystems. Accurate estimates of active prairie dog colony area are needed to assess the status of the species and evaluate the effects of management actions. In 2008, Montana Fish, Wildlife and Parks conducted a survey of potential black-tailed prairie dog habitat. Using fixed-wing aircraft and an aerial line-intercept method, we surveyed 771 transects totaling 56,530 km in 32 counties in central and eastern Montana, USA, excluding tribal lands. We recorded 667 black-tailed prairie dog colony intercepts totaling 336,636 m in 21 counties. Ground intercepts were 1.091 (95% credible intervals = 1.087–1.094) times longer than air intercepts. The estimated percent of colonies classified as active from the air that were active on the ground was 86.8% (95% credible intervals = 77.9–93.5%). Corrected estimates resulted in 77,430 ha (95% credible intervals = 69,480–83,380) of active and 12,990 ha (95% credible intervals = 7,039–20,970) of inactive black-tailed prairie dog colonies. We conducted a sensitivity analysis of the estimated area of active prairie dog colonies by reducing a percentage of long intercepts assumed to be entirely active. More than 30% of active intercepts >750 m in length would need to, in fact, be inactive in order for our active colony area estimates to differ >10,000 ha (13%; i.e., outside of our margin of error) from our estimates. Aerial line-intercept methods provide a reliable and repeatable method for obtaining estimates of active and inactive prairie dog colony area over large areas. Our estimates provide the basis for long-term monitoring of prairie dogs on a landscape scale.

Fiona A. Stewart, Alex K. Piel
Termite fishing by wild chimpanzees: new data from Ugalla, western Tanzania
Primates, May 2013

Chimpanzees manufacture flexible fishing probes to fish for termites in Issa, Ugalla, western Tanzania. These termite-fishing tools are similar in size and material to those used by long-studied communities of chimpanzees in western Tanzania (Pan troglodytes schweinfurthii) and in West Africa (P. t. verus), but not central African populations (P. t. troglodytes). This report adds to the patchwork of evidence of termite-fishing tool use behaviour by chimpanzees across Africa.

Gabriella Gronqvist, Mark Kingston-Jones, Adam May, Julia Lehmann, The effects of three types of environmental enrichment on the behaviour of captive Javan gibbons (Hylobates moloch), Applied Animal Behaviour Science, Available online 30 May 2013, ISSN 0168-1591, 10.1016/j.applanim.2013.04.021.
Studies on a large variety of species have shown that enrichment can be successfully used to encourage natural behaviours, to decrease rates of abnormal behaviour and to improve welfare in captive animals. However, whether or not a specific enrichment device is enriching depends on the species and its circumstances in captivity. In this study, we investigate the effect of three different enrichment devices (a novel object, an olfactory and a food-based enrichment) on the behaviours of four groups of captive zoo-housed Javan gibbons (Hylobates moloch). This species is endangered in the wild, and captive populations form an important resource in ongoing conservation efforts. We investigated how three different enrichment devices affect gibbon activity budgets and stress related behaviours. We further assessed to what extent gibbons habituated to these devices over two periods of five consecutive exposure days. We found that gibbons engaged on average 0.08 times per minute with the foraging device, 0.03 times per minute with the novel object and 0.02 times per minute with the olfactory enrichment. All three enrichment devices were found to significantly increase the frequency of foraging behaviours, while the novel object and the foraging box were also found to increase rates of singing behaviour. No change in the already low rates of stress-related behaviours was found following exposure to enrichment devices and habituation to the devices was generally absent. We conclude, that all three enrichment devices offer a species-appropriate, practical and inexpensive form of environmental enrichment for captive Javan gibbons, which may enhance the wellbeing of captive groups.

Victor A. Stiebens, Sonia E. Merino, Christian Roder, Frédéric J. J. Chain, Patricia L. M. Lee, and Christophe Eizaguirre
Living on the edge: how philopatry maintains adaptive potential
Proc. R. Soc. B July 22, 2013 280 1763 20130305; doi:10.1098/rspb.2013.0305 1471-2954

Without genetic variation, species cannot cope with changing environments, and evolution does not proceed. In endangered species, adaptive potential may be eroded by decreased population sizes and processes that further reduce gene flow such as philopatry and local adaptations. Here, we focused on the philopatric and endangered loggerhead sea turtle (Caretta caretta) nesting in Cape Verde as a model system to investigate the link between adaptive potential and philopatry. We produced a dataset of three complementary genomic regions to investigate female philopatric behaviour (mitochondrial DNA), male-mediated gene flow (microsatellites) and adaptive potential (major histocompatibility complex, MHC). Results revealed genetically distinct nesting colonies, indicating remarkably small-scale philopatric behaviour of females. Furthermore, these colonies also harboured local pools of MHC alleles, especially at the margins of the population’s distribution, which are therefore important reserves of additional diversity for the population. Meanwhile, directional male-mediated gene flow from the margins of distribution sustains the adaptive potential for the entire rookery. We therefore present the first evidence for a positive association between philopatry and locally adapted genomic regions. Contrary to expectation, we propose that philopatry conserves a high adaptive potential at the margins of a distribution, while asymmetric gene flow maintains genetic connectivity with the rest of the population.

Fennessy, J., Bock, F., Tutchings, A., Brenneman, R. and Janke, A. (2013), Mitochondrial DNA analyses show that Zambia’s South Luangwa Valley giraffe (Giraffa camelopardalis thornicrofti) are genetically isolated. African Journal of Ecology. doi: 10.1111/aje.12085
Thornicroft’s giraffe, Giraffa camelopardalis thornicrofti, is a geographically isolated subspecies of giraffe found only in north-east Zambia. The population only occurs in Zambia’s South Luangwa Valley, an area which interestingly places it between the current distribution of Masai (G. c. tippelskirchi) giraffe to the north, and the Angolan (G. c. angolensis) and South African (G. c. giraffa) giraffe in the south-west and south, respectively. Specific studies have been undertaken on the ecology of this subspecies, but their population genetics remains unknown. We studied 34 individuals from the South Luangwa National Park and adjacent Lupande Game Management Area and seven individuals from northern Botswana. The complete cytochrome b and control region sequences of the mitochondrial genome were sequenced and analysed together with database data by maximum likelihood tree reconstruction and maximum parsimony network analyses. The giraffe from Zambia’s South Luangwa Valley are most closely related to the subspecies G. c. tippelskirchi and part of their radiation. However, they form a unique population that would benefit from increased research and conservation management.

Zootaxa 3666 (3): 337–344 (31 May 2013)
A new deep-water goatfish of the genus Upeneus (Mullidae) from Vanuatu, South Pacific

A new goatfish, Upeneus vanuatu (Mullidae), is described based on five specimens collected off two islands of Vanuatu (South Pacific), at depths of 191–321 m, and compared with five closely related species: Upeneus davidaromi (Red Sea), U. mascareinsis (Western Indian Ocean), U. stenopsis (northern Australia, Philippines, 127–275 m), and the more shallow-occurring Indo-West Pacific species U. subvittatus (26–120 m) and U. vittatus (<100 m). The new species can be distinguished from all other congeneric species by the combination of four characters: number of gill rakers on lower limb, caudal-peduncle depth, interorbital length, and interdorsal distance. Strong allometric variation in body form between the holotype and the four smaller paratypes was found. Based on the lack of lateral body stripes, a rather narrow caudal peduncle depth, and large eyes in adults as common characteristics for U. subvittatus and the four deep-water Upeneus species, the so-called “stenopsis” species group can be distinguished from four other species groups that were established in earlier studies in order to facilitate intrageneric comparisons. The ecological and evolutionary significance of deep-water goatfishes is briefly discussed. Zootaxa 3666 (3): 358–368 (31 May 2013)
A new Nototriton (Caudata: Plethodontidae) from Parque Nacional Montaña de Botaderos in northeastern Honduras

The highlands of northeastern Honduras remain under-characterized in terms of biological diversity, as exemplified by the regularity of new amphibian and reptile taxa discoveries. Following the recent description of a new species of Nototriton from the Sierra de Agalta in northeastern Honduras, we report the discovery of a second new species of Nototriton from the nearby Parque Nacional Montaña de Botaderos. This new taxon, Nototriton mime sp. nov., is distinguished from other Nototriton by its distinctive pale brown dorsal coloration in adult males, relatively large nares, a relatively broad head,
mitochondrial sequence divergence, and phylogenetic relationships, and is geographically isolated from other populations of Nototriton.

Jason M. Townsend, Charles T. Driscoll, Red-backed salamander (Plethodon cinereus) as a bioindicator of mercury in terrestrial forests of the northeastern United States, Ecological Indicators, Volume 34, November 2013, Pages 168-171, ISSN 1470-160X, 10.1016/j.ecolind.2013.04.017.Despite concerns over the widespread deposition of mercury (Hg) in remote forested areas of the northeastern United States (U.S.), little information is available on the bioaccumulation of Hg in this region’s terrestrial fauna. There is a strong need to develop baseline data on appropriate bioindicator species for this area, and here we report Hg concentrations in one of the most widely distributed vertebrates in forested areas, the red-backed salamander (Plethodon cinereus). To inform the use of this species as a bioindicator of Hg accumulation, we assessed ratios of bioavailable methylmercury (MeHg) to total Hg, and techniques for non-destructive sampling along an elevational gradient of increasing forest floor Hg concentrations. Total Hg in body samples was 70% MeHg, and Hg concentrations in tail-clips, which can be collected non-lethally, were positively correlated with body concentrations. Mercury concentrations in salamanders increased 2.4-fold along an increasing elevational gradient of Hg in soils. We conclude that Hg concentrations in P. cinereus can act as a biomonitoring tool for broad areas of remote terrestrial forests, and may help identify regions and landscape characteristics of particular concern for Hg bioaccumulation.

Buuveibaatar, B., Fuller, T. K., Fine, A. E., Chimeddorj, B., Young, J. K. and Berger, J. (2013), Changes in grouping patterns of saiga antelope in relation to intrinsic and environmental factors in Mongolia. Journal of Zoology. doi: 10.1111/jzo.12045
Factors that affect group sizes in large ungulates are generally poorly understood for species from remote regions. Understanding grouping patterns is important for effective species management, but is lacking for the endangered Mongolian saiga (Saiga tatarica mongolica). We studied seasonal changes in the group size and social structure of saigas in relation to environmental and anthropogenic factors in western Mongolia during 2009–2012. To identify group size and composition, we observed saigas monthly while conducting monitoring surveys, and weekly while tracking radio-collared animals. We observed 9268 individuals; median group size was 6.5 (se = 1.7; range = 1–121), and groups of 1–5 animals were most common. Seasonality exerted strong effects with the smallest groups in June and largest in December. The largest mixed and nursery groups formed during pre-rutting and summer seasons, respectively, but no seasonal differences were detected for bachelor groups. The best fitting model, including Normalized Difference Vegetation Index, predation rate and season as covariates, explained ∼76% of the variation in monthly ‘typical’ group size. Our results are concordant with studies of other arid-adapted ungulates and suggest vegetation productivity, predation rate and biological cycles are responsible for saiga grouping patterns in Mongolia.

Dieser Beitrag wurde unter Wissenschaft/Naturschutz abgelegt und mit , , , , , , , , , , , verschlagwortet. Setze ein Lesezeichen auf den Permalink.

Kommentar verfassen