bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of mustelid species: otter (Lutra lutra), American mink (Mustela vison) and polecat (Mustela putorius), by analysis of DNA from faecal samples
Authors: Hansen M. M. , Jacobsen L. 
Published: February 2006

AbstractThe abundance of mink, otter, and polecat may be inferred from records of their scats, and the feeding biology of the species is often studied by analysis of skeletal remains and other hard parts in faeces. However, in some situations it is difficult to distinguish between faeces from these three mustelid species. A method is described for assigning faeces to these three mustelid species, based on analysis of DNA extracted from their scats. Mustelid‐specific primers were developed for PCR amplification of a part of the mitochondrial cytochrome b gene, and two restriction enzymes were found to detect species‐specific sequence variation. Analysis of DNA from different faecal samples showed that the results were reproducible and that the approach provided an efficient method of species identification.
Diet and nectarivorous foraging behaviour of the short‐tailed bat (Mystacina tuberculata)
Authors: Arkins A. M. , Winnington A. P. , Anderson S. , Clout M. N. 
Published: February 2006

AbstractThere are two microchiropteran bat species in New Zealand: the long‐tailed bat Chalinolobus tuberculatus and the short‐tailed bat Mystacina tuberculata. Both species coexist on Little Barrier Island in the Hauraki Gulf, New Zealand. In this study we examined the diet of M. tuberculata, and the activity levels of both bat species associated with Metrosideros excelsa, a native flowering plant and potential nectar source, on Little Barrier Island. Between November 1994 and February 1996, M. tuberculata were caught in mist‐nets, and their faecal pellets were collected for later dietary analysis. In addition, pollen samples were collected from the fur of bats caught during December 1995 and January 1996. Faecal analysis showed that M. tuberculata on Little Barrier Island exhibits a high degree of omnivory, with its diet comprising flying and non‐flying arthropods, and also pollen and other plant material. During December 1995 and January 1996, the activity levels of both bat species associated with flowering and non‐flowering M. excelsa trees were investigated by recording bat echolocation calls with automatic detecting and recording units. Significantly higher numbers of M. tuberculata echolocation calls were recorded near flowering M. excelsa trees than near non‐flowering ones, whereas the numbers of C. tuberculatus calls did not differ significantly between flowering and non‐flowering trees. These results contribute further to the existing evidence for nectarivory in M. tuberculata.
Environmental determinants of primate abundance in Maracá Island, Roraima, Brazilian Amazonia
Authors: Pontes Antonio Rossano Mendes 
Published: February 2006

AbstractA primate community was studied in a fluvial tropical rain forest island, in the northernmost part of Brazilian Amazonia, in the State of Roraima. Density and biomass were determined, and the differences between the forest types were assessed. The line‐transect method was used from the east towards the centre of the island. No previous studies had been carried out in this remote undisturbed area. Density and biomass varied between the forest types, as well as between frugivorous primates; the smaller‐bodied species were more abundant in the forest that was richer in fruiting trees, while they were absent from a monodominant forest. The folivorous, or partly folivorous, primates were abundant in those forests with less fruiting trees. The abundance of the primates in the different forest types was shown to be a function of food availability.
Seasonal changes in diet and diet selection of great bustards (Otis t. tarda) in north‐west Spain
Authors: Lane S. J. , Alonso J. C. , Alonso J. A. , Naveso M. A. 
Published: February 2006

AbstractFaecal analysis was used to study the diet of great bustards in north‐west Spain on a monthly basis for 1 year. After correction for differential digestibility, the diet composition by dry weight varied from 48.4% green plant material, 40.9% invertebrates and 10.6% seeds in August, to consisting almost completely of green plant material between December and March. At least 65 plant species were represented in the green plant material, but most occurred rarely and the bulk of this portion of the diet consisted of alfalfa. Eight invertebrate orders were detected in the faeces, of which Coleoptera, Hymenoptera and Orthoptera were most important by numbers. From August to November when seeds were important by dry weight, wheat and barley seeds were found in more faecal pellets than other species. Estimates of use and abundance were obtained to evaluate diet selection in the green plant material and invertebrate components. Alfalfa was strongly selected throughout the year, but grasses were used less often than expected. Coleoptera were always eaten in greater numbers than expected, Orthoptera were used either in proportion to abundance or less often than expected, and Hymenoptera less often in May, more often in September and November, and as expected at other times. The results support the suggestion that increasing alfalfa cultivation would be a useful management tool for maintaining endangered great bustard populations, but further work on the cost‐effectiveness of this option is needed.
Ontogenetic changes in mineralization and bone geometry in the femur of muskoxen (Ovibos moschatus)
Authors: Heinrich R. E. , Ruff C. B. , Adamczewski J. Z. 
Published: February 2006

AbstractBone mineralization and bone geometry at femoral midshaft were analysed for 33 muskoxen Ovibos moschatus ranging in age from 3 weeks to 4.5 years and in body mass from 9 to 215 kg, to assess changing mechanical properties associated with postnatal ontogeny. Analysis of the mineral density of bone (BMD) indicates little or no change in femoral mineralization until after 4 months of age. Between 4 and 6 months of age BMD increases markedly, and complete mineralization occurs by about 18 months of age. Femoral length (L) and bone strength (as measured by Z, the section modulus) scale negatively allometric with body mass (L ∞ M0.26 and Z ∞ M0.88) indicating that neonate muskoxen have longer and stronger femora for their body size than do older animals. When the neonate data were excluded, however, bone length and bone strength regressed against body mass did not differ significantly from isometry (L ∞ M0.32 and Z ∞ M1.03), implying that different growth trajectories characterize postnatal ontogeny before and after 4 months of age. As a consequence of the timing of ontogenetic changes in bone mineralization and cross‐sectional geometry, safety factors calculated for the femur (derived from estimates of peak bending stress and fracture strength) are largest and smallest in neonates and 4‐month‐old calves, respectively. It is hypothesized that increased bone mineralization and accompanying diaphyseal stiffness after 4 months of age are necessary to maintain structural integrity of the femur.
Specific distinctness and biogeography of the dwarf chameleons Brookesia minima, B. peyrierasi and B. tuberculata (Reptilia: Chamaeleonidae): evidence from hemipenial and external morphology
Authors: Glaw Frank , Vences Miguel , Ziegler Thomas , Böhme Wolfgang , Köhler Jörn 
Published: February 2006

AbstractIn a recent paper Raxworthy & Nussbaum (1995) included the Madagascan dwarf chameleons Brookesia peyrierasi and B. tuberculata in the synonymy of B. minima, regarding known hemipenial differences between B. tuberculata and B. peyrierasi as artefacts. Our studies demonstrate that the hemipenis description of B. tuberculata by Brygoo & Domergue (1975) was largely correct and referred to unusual but real structures. The enormous differences in the hemipenis morphology of B. tuberculata (hemipenes of six specimens examined) and B. peyrierasi (hemipenes of five specimens examined) strongly suggest that they are not conspecific. Furthermore, morphological differences in the arrangement of head crests and expression of supraocular spines were noted between these two taxa and B. minima. The differentiation of the three taxa is furthermore corroborated by both univariate and multivariate analyses of morphometric data. We therefore propose to consider Brookesia minima, B. peyrierasi, and B. tuberculata as distinct species. This conclusion corroborates the validity of biogeographic regions as suggested from the analysis of distribution patterns of other Brookesia species.
Forage chemistry and fermentation chambers in Svalbard reindeer (Rangifer tarandus platyrhynchus)
Authors: Sørmo W. , Haga Ø. E. , Gaare E. , Langvatn R. , Mathiesen S. D. 
Published: February 2006

AbstractSeasonal changes in the species composition and fibre content of plant fragments in the rumen and the gross anatomy of the gastrointestinal tract were investigated in Svalbard reindeer Rangifer tarandus platyrhynchus in western parts of Spitsbergen (Nordenskiöld Land (NL), 78°N), where the tundra vegetation is relatively abundant, and on the island of Nordaustlandet ((NA) 81°N) where, in the polar desert, plants are scarce. Reindeer were killed while grazing on NL in autumn (n= 19) and in winter (n= 10) and on NA in summer (n= 10) and in winter (n= 3). Rumen contents included mainly mosses and grasses in specimens from NL and mainly Saxifraga spp. in specimens from NA. The plant cell wall content of the dry organic matter in the rumen‐reticulum (RR) ranged from 55% to 77% and from 43% to 57% in NL and NA specimens, respectively, and did not vary between seasons. In autumn, the wet weight of the contents of the RR ranged from 13% to 20% of body mass (BM) in females on NL and from 14% to 24% of BM in adult reindeer in winter. On NA, the wet weight of the contents of the RR in adult animals ranged from 15% to 20% of BM in summer and from 15% to 17% of BM in winter in NA. The ratio of the wet weight of the contents of the distal fermentation chamber (DFC) to the wet weight of the contents of the RR was 1:8 in females in autumn, compared to 1:6–1:7 in adult animals on NL in winter. The ratio of the wet weight of the DFC to the wet weight of the RR ranged between 1:8–1:10 in summer, compared to 1:7 and 1:8 in winter. There were no significant differences in the size of plant particles in the RR contents in females from the two areas in any season, indicating that ruminal plant particle size was not influenced by the concentration of plant cell walls in the rumen contents. We conclude that the degree of filling of the gastrointestinal tract of these reindeer was therefore principally a function of plant fibre chemistry. Svalbard reindeer are adaptable intermediate feeders but they have, nevertheless, developed a large DFC similar to that of concentrate selectors.
The remarkable anatomy of the giraffe's neck
Authors: Solounias N. 
Published: February 2006

AbstractMammalian cervical vertebrae 6 and 7 and thoracic vertebra 1 possess many distinguishing characteristics. In the giraffe, bone morphology, muscle origins and insertions, as well as the location of the brachial plexus (described as many osteological and some soft tissue characters) are identical to those in other mammals but are all displaced posteriorly by one vertebra. There are two exceptions to these observations: the pre‐sacral vertebral count is unchanged when compared with that in the okapi and C7 supports the first rib. Thus, one vertebra has been added in the neck of the giraffe between cervical 2 and 6, and some type of structural blending has occurred in the region of the first rib. The junction of the giraffe neck with the thorax is unusual and results in a protruding forelimb. It is possible that the unusual position of the neck relates to balancing of a cantilevered neck and head upon a relatively slight body. Characteristic drinking postures may have also influenced the observed anatomical modifications.
The effect of lamellae autotomy and sexual size dimorphism on startle‐response performance in larvae of a lestid damselfly (Odonata)
Authors: Stoks R. 
Published: February 2006

AbstractSwimming is the most important escape mechanism in lestid damselflies. The effect of lamellae autotomy and sexual size dimorphism on startle‐response performance was studied experimentally in larvae of the lestid damselfly Lestes sponsa. In contrast with the prediction of McNeill (1960) that lamellae loss would not affect swimming speed in fast swimmers such as Lestes larvae, swimming performance decreased in a quadratic way with the removal of subsequent lamellae. Lamellae autotomy therefore will considerably reduce the probability of escape from a predator. Larger larvae swim faster than smaller ones of the same instar. This may contribute to a higher survival of larger larvae compared with smaller ones when confronted with both conspecific and heterospecific predators. Despite larvae showing sexual size dimorphism, with females being larger, no difference in swimming speed between the sexes was found.
Reproductive success, colony size and roost temperature in attic‐dwelling bat Myotis myotis
Authors: Zahn Andreas 
Published: February 2006

AbstractSome cave‐dwelling bat species such as Myotis myotis now also roost in buildings in parts of their range. I studied the effects of roost temperature and colony size on reproductive success of colonies of M. myotis located in buildings. Temperatures in attics fluctuated considerably and altered the thermal conditions at the roost during the breeding season. Inter‐colony variation was recorded with respect to factors indicating reproductive success (number, growth, and mortality of juveniles until fledging). However, over‐winter survival varied more between years than between colonies. Colony size did not influence development or mortality of juveniles. High average roost temperatures favoured development of juveniles but did not influence mortality. Unlike the situation in caves, large colony sizes are not advantageous in buildings
Ecological factors affecting the feeding behaviour of pangolins (Manis temminckii)
Authors: Swart J. M. , Richardson P. R. K. , Ferguson J. W. H. 
Published: February 2006

AbstractThe diet and foraging behaviour of 15 radio‐tagged pangolins were studied in the Sabi Sand Wildtuin for 14 months, together with the community composition and occurrence of epigaeic ants and termites. Fifty‐five ant and termite species of 25 genera were trapped in pitfalls of which Pheidole sp. 2 was the most common (27% occurrence). Five termite and 15 ant species were preyed on by pangolins. Six of these species constituted 97% of the diet while ants formed 96% of the diet. Anoplolepis custodiens constituted the major component of the pangolins' diet (77% occurrence) while forming only 5% of the trapped ants. Above‐ground ant and termite activity was higher during summer than during winter (an 11‐fold difference for A. custodiens), and the above‐ground activity was also higher during the day than at night. Pangolins fed for 16% of their foraging time. However, 99% of the observed feeding bouts (mean duration 40 s) were on subterranean prey. The mean dig depth was 3.8 cm. Prey from deeper digs were fed upon for longer periods. A model taking into account various ant characteristics suggests that ant abundance and ant size are the two most important factors determining the number of feeding bouts that pangolins undertake on a particular ant species. Temperature effects on ant activity and their nest characteristics may exclude pangolins from parts of southern Africa.
The social organization and breeding system of Brants' whistling rat (Parotomys brantsii)
Authors: Jackson T. P. 
Published: February 2006

AbstractBrants' whistling rat Parotomys brantsii is a gregarious rodent that undergoes marked population fluctuations every few years. Previous studies have variously described them as solitary or social. In this field study, based on direct observations, the social structure and breeding system of a population that almost quadrupled over 7 months was investigated. At the onset of the breeding season, the animals were solitary, each occupying a separate warren. By the end of the breeding season, there was multiple occupancy of some warrens. Each individual maintained a discrete territory within the warren, and exhibited no apparent social behaviour. Outside the breeding season the behaviour of males and females did not differ and both remained at their resident warrens. During the breeding season male P. brantsii visited more neighbouring warrens than did the females, and their visits were to unoccupied warrens or to those occupied by females. Females tended to remain within their own warren. Both sexes avoided warrens occupied by males and few male–male interactions were observed. Females were solicited at their warrens by males, who were frequently chased away. There was, however, evidence that reproductively receptive females were more tolerant of males, who may guard females following mating. This breeding system, based on competitive mate searching by males, and not overt aggression between males, parallels the scramble competition polygyny described for a number of other species, including North American ground squirrels.
The timing of hunting in short‐eared owls (Asio flammeus) in relation to the activity patterns of Orkney voles (Microtus arvalis orcadensis)
Authors: Reynolds Peter , Gorman Martyn L. 
Published: February 2006

AbstractUsing radio‐telemetry, short‐term cycles of activity, with a period of about 3 h, were detected in Orkney voles Microtus arvalis orcadensis and in one short‐eared owl Asio flammeus, their principal predator. Visual observations showed that owls from four adjacent nests had similar activity patterns. These cycles tended to be synchronous both within and between the two species. Short‐eared owls thus appeared to be foraging optimally by timing their hunting to coincide with peaks in vole activity, i.e. at times of maximum potential yield. The extent of diurnal activity in short‐eared owls varied seasonally. Daytime activity was conspicuous for only a short period in spring and early summer. Otherwise owls were almost exclusively nocturnal. These seasonal changes in activity were probably a response to variations in vole diurnality, vole population size and daylength. Harassment and kleptoparasitism may have been additional influences that interacted with these seasonal factors to determine the extent of preferred nocturnal hunting. In addition, it is possible that the energetic constraints of breeding may force owls to hunt during daylight. Were males only to hunt at night then they may not be able to provide enough food for their mate and young at a time when nights are short and vole populations are only starting to increase.
Diversity and structure of terrestrial small mammal communities in different vegetation types on the Accra Plains of Ghana
Authors: Decher Jan , Bahian Luri Kanton 
Published: February 2006

AbstractSmall mammal communities (shrews and rodents) were studied using mark‐and‐recapture techniques from November 1991 to June 1992 at six sites on the Accra Plains of Ghana. The sites were two traditionally protected ‘sacred groves’, two plots in the legally protected Shai Hills Resource Reserve, and two fire‐protected sites: secondary forest and a Gmelina tree plantation. A total of 241 individuals representing four species of shrews and nine species of rodents was caught. Abundance, diversity, and composition of small mammals varied greatly between sites. Praomys tullbergi was the most abundant species in the sacred groves, whereas Mastomys erythroleucus dominated in the fire‐protected site and in the plantation. The more open grassland areas in the Shai Hills were dominated by Lemniscomys striatus and Uranomys ruddi. Shrews were caught only in forests having dense leaf litter. Legally protected reserve sites had the highest diversity of small mammals but population densities were low. In contrast, the sacred groves had lower diversity levels but much higher population densities, resulting in 1.9 to 14.6 times the biomass of any of the other sites. The rodents Mus minutoides and Hylomyscus alleni and the shrews Crocidura buettikoferi and C. lamottei were found only in the sacred groves. Sacred groves play an important socio‐cultural role. Their local ecological and economic importance as reservoirs for rare and useful plants is well known. This study shows that they are also important refuges for certain small mammal species and support characteristic mammal communities. An attempt to measure the impact of the invading exotic tree Azadirachta indica (neem tree) on small mammals was inconclusive, although trapping success was low in areas with dense stands of neem.
Body measurements on 40 species of mammals from French Guiana
Authors: Richard‐Hansen C. , Vié J.‐C. , Vidal N. , Kéravec J. 
Published: February 2006

AbstractMore than 3000 mammals were captured and translocated during a rescue operation conducted in French Guiana during the filling of a hydroelectric dam, a unique opportunity to gather biological data on many aspects of the Guianan fauna. All animals were identified, anaesthetized, measured, and biological samples (blood, skin biopsies) were collected and preserved. This study presents morphological data on all captured mammals belonging to 40 species of Marsupialia, Xenarthra, Primates, Carnivora, Artiodactyla, Rodentia and Sirenia. Data reported here include weight, shoulder height, head and body, tail, hind foot, head, and ear lengths, and some additional measurements for particular species. Some species were found to be larger than previously reported, which may be attributed to the large sample size, circumstances of data collection or to geographic variations. Such basic data appear to be hardly available on neotropical mammals, and thus provide useful comparative material for further studies.
The effects of predators on fragmented prey populations: a case study for the conservation of endangered prey
Authors: Macdonald David W. , Mace Georgina M. , Barretto Guillermo R. 
Published: February 2006

AbstractWe considered the problem of conserving small populations of prey by reviewing observational and field experiments in search of general answers to the question of how predators impact upon their prey. We then explored the likely effectiveness of predator control as a conservation tool by simulating a small, fragmented population of prey. We chose red grouse in Britain as an example of this general predicament. An individual‐based population simulation model was used to simulate the fate of a small red grouse population. The model was used to investigate the relative impacts of predation, habitat changes and stochastic factors associated with small population size on the viability of the population. Although most predator–prey studies have been undertaken in temperate regions and only four studies found evidence of regulation, some generalizations arose. Predation can limit populations but generally did not drive the prey population to extinction. Extinction was more likely in cases involving an introduced predator on islands or in isolated prey populations. The simulation model showed that at small population sizes the stochastic factors were always significant, whereas environmental variation and habitat change had the greatest impact on large populations over the long term; predation was only a significant threatening factor when it occurred at a high rate, was more severe over the long term when predators took a constant proportion of the prey base, and when predation was across all age classes.