bluuebunny/crossref_metadata_2025_split huggingface dataset:
Social behaviour and social organization of marsupials
Authors: RUSSELL ELEANOR M. 
Published: April 2008

ABSTRACTDetailed studies of social behaviour and social organization are available at present for relatively few marsupial species, but a considerable body of information is to be found in the literature, and this review attempts to draw it together. The most important avenues of communication appear to be olfactory and auditory, with visual communication relatively unimportant in animals which are predominantly nocturnal. For each family, the different patterns of social organization which occur are discussed in terms of group size, composition and dispersion, mating system, pattern of parental care and nature of social interactions. This information forms the basis of a discussion of how environmental and other factors may have influenced the evolution of social organization. The majority of marsupial species are not group living. Nevertheless, in some species of the families Petauridae, Macropodidae and Phalangeridae, a variety of more or less stable small groups are found, including monogamous pairs and harem groups. Such groups usually have some part of their home range which is exclusive and includes some localized resource. Many of the larger kangaroos of the family Macropodidae are generally seen in groups which may be part of a changing nomadic population or sub‐units of a resident population which share a common home range. Minor differences in social organization between species appear to be due mainly to availability and dispersion of food resources. Overall, long‐term bonds between males and females are uncommon in marsupials, and the mating system is generally some form of promiscuity. It is argued that the marsupial mode of reproduction and parental care offers no advantage to male or female in long‐term bond formation. The female is able to rear young on her own and the male can increase his fitness more by encountering as many females as possible. Hence exclusive home ranges, whether defended or not, are uncommon.
The bioassay of mammalian olfactory signals
Authors: MACKINTOSH J. H. 
Published: April 2008

SUMMARYThe bioassay of chemical signals in mammals presents a number of problems. Many of these difficulties are the result of the complexity of the behaviour which has to be analysed and of the odiferous output itself. Additionally, it is usual for the response to the odour to be affected by information from other sensory modalities, by experience and by the spatial and social context. This degree of variability and of flexibility which is characteristic of mammals also has the result that concepts such as ‘pheromone’, which were originally developed in simpler organisms, can be seriously misleading.Although valuable information can be gained by less direct methods, a bioassay is only likely to be successful in the identification of active substances if:1. there is a clearly defined behavioural or physiological response to the odour,2. the method of testing actually measures this response,3. the situation used for testing is as close as possible to that in which the response naturally occurs,4. in the case of a behavioural response, the recording technique is as detailed as possible so that ambiguous results are avoided,5. an adequate test population is available to allow repeated testing,6. considerable resources are available for chemical analysis.Although it is not easy to fulfil all of these requirements at one time, olfaction is of such importance in mammalian communication that the attempt to do so will always be valuable.
Ecology of small rodents in Africa
Authors: DELANY M. J. 
Published: April 2008

AbstractThis account considers progress in research on small rodent ecology since about 1970. While some ecological survey has been undertaken throughout much of the continent, the main research thrust has involved the detailed examination of population processes in a range of habitats from deserts to tropical rain forests. The deserts and semi‐arid regions support a range of species with some better adapted to these harsh conditions than others. The adaptations manifest themselves in different life history strategies e.g., opportunistic with high turnover species, or low turnover‐low reproduction species, in their physiology e.g., adaption to water retention, and in their behaviour e.g., avoiding heat of day. Long term studies show large numerical fluctuations with a quick response by some species to favourable conditions caused by relatively high precipitation. In the savanna and grasslands, studies have centred on population dynamics, the relationship between food and breeding, reproductive and life history strategies and the determination of niche. These have been approached through the study of groups of species in particular localities as well as by the examination of individual species. In these habitats populations are more stable and less erratic than in semi‐arid regions. Perturbations, particularly fire, can have various effects on the numbers and species composition of the disturbed area. In the tropical rain forest population fluctuations are modest and may take up to 2–3 years to pass from a peak to a trough and back again. Breeding typically extends over much of the year with, apparently, the greatest number of rodents occurring on the ground surface. Bush and temporary farms derived as a result of forest modification support more animals (and often more species) than forest. The niches occupied by forest rodents are poorly understood and very little is known of the ecology within the canopy. In most localities a small number of species are abundant and the remainder much less frequent.
Helminth parasites of British rodents and insectivores
Authors: LEWIS J. W. 
Published: April 2008

AbstractField and laboratory studies on the helminths of rodents have mainly involved direct life‐cycle nematodes (of the super families Rhabditoidea, Oxyuroidea, Trichuroidea and Trichostrongyloidea) and, to a lesser extent, indirect life‐cycle cyclophyllidean cestodes (of the families Catenotaeniidae and Hymenolepididae). In insectivores on the other hand, because of their different feeding habits, the composition of the helminth fauna largely comprises hymenolepid and dilepidid cestodes together with brachylaemid and dicrocoeliid digeneans, the life cycles of which are little known. The value of further studies on the biogeography of helminths of rodents and insectivores in the British Isles is emphasized. The role of rodent nematodes as laboratory models for chemotherapy is also discussed.
Population dynamics of helminth parasites in wild and laboratory rodents
Authors: SCOTT M. E. , LEWIS J. W. 
Published: April 2008

AbstractThis paper reviews the host‐helminth interactions that are of importance in regulating both the abundance of helminth parasites of rodents and the host population abundance. Parasite density has an effect on the ability of individual parasites to grow, reproduce and survive within the definitive host, and it also influences the ability of the infected host to survive and reproduce. The severity of the impact of such density‐dependent responses is related to the pattern of parasite distribution within the host population. The potential of helminth parasites to regulate the abundance of a small mammal population is illustrated using an experimental example. Areas identified for further research include (i) an investigation of the relative importance of parasite density‐dependent effects on parasite and host survival and reproduction for specific host‐helminth associations; (ii) more research into the impact of helminth density on host reproduction; and (iii) research into the impact of helminths on the population dynamics of small mammal populations using field and laboratory experiments designed to assess the relative importance of helminths in regulating the abundance of their host populations.SummaryIn this paper we have considered parasite density as an important determinant of parasite and host population dynamics. Because the relative impact of density on different population processes will differ for different helminths, researchers interested in accounting for temporal dynamics of a specific parasite will need to investigate the density‐dependent processes involved in the life cycle of that helminth.Although interactions between the population biology of both the host and helminth parasite are of fundamental importance to the population dynamics of the parasite, they also are important in determining the population dynamics of the infected host population. Because helminths, by definition, must have an impact on the ability of the host population to survive or reproduce they, therefore, also have the potential to regulate the abundance of the host population (Anderson & May, 1978; Anderson, 1979). More research is needed on the effect of parasite density on the rate of reproduction of infected hosts. Finally, given recent theoretical and experimental evidence that parasites can regulate mammal populations, much work is needed to determine conditions when this actually occurs in the field.
Environmental fluoride and fluorosis in mammals
Authors: WALTON K. C. 
Published: April 2008

AbstractFluoride, originating either naturally from rocks and soil or from modern industrial processes, can cause severe and crippling damage in humans and animals. In vertebrate species, the skeleton is particularly susceptible; outgrowths on bones and fusion of joints cause lameness and lack of mobility. Teeth may be badly worn and damaged, often losing their enamel. The occurrence and effects of fluoride in wild mammals are reviewed.
Timing of mating in the Common Seal (Phoca vitulina)
Authors: THOMPSON P. 
Published: April 2008

AbstractIt is generally believed that British Common Seals mate after the moult, in late summer. In contrast, evidence from other parts of their range suggests that mating occurs before the moult, at the end of lactation. This paper reviews the evidence for the timing of mating from all parts of the range of this species, and presents data on seasonal changes in male sexual behaviour at a haulout site in Orkney, U.K. British Common Seals do mate at the end of lactation, as in other areas; the presumed precopulatory display described in previous studies is more likely to have been play between juveniles or sub‐adults.
Energetic strategies of shrews: ecological constraints and evolutionary implications
Authors: GENOUD M. 
Published: April 2008

AbstractData on various features influencing resource acquisition and allocation of energy in Soricidae are reviewed. The relationships between these features are examined at the three functional levels that constrain the energetic design of shrews: the maintenance of homeostasis (rate of metabolism and temperature regulation), the balancing of the energy budget (e.g. the influence of body mass, activity rate, various energy saving mechanisms and home range size), and the allocation of energy towards reproduction (e.g. the influence of litter size). Two major contradictory energetic designs may be recognized: one rather expensive design that is observed in cold and temperate climates with relatively predictable fluctuations in resource availability (e.g. in Sorex and Neomys), and another much less expensive design that is observed mainly in warm or unpredictable environments (e.g. in Crocidura, Suncus and Notiosorex). It is speculated that climate and resource availability impose narrow limits on the evolution of these energetic strategies, mainly because of the small thermal inertia and reduced energetic autonomy of shrews.
A twenty‐five‐year chronicle of a group of captive nocturnal prosimians (Perodicticus potto)
Authors: COWGILL U. M. , STATES S. J. , STATES K. J. 
Published: April 2008

ABSTRACTFour Perodicticus potto survived captivity from 4 to 24‐6 years. The male that died on 16th July 1984 was sexually mature at the time of his capture in December 1959, and thus is believed to have been slightly older than 26 years at the time of his death. These data suggest a longer life span for this species than has previously been recorded in the published literature, and do not conform well with information from other terrestrial mammals, showing a general trend of increasing longevity with increasing size (length). A 25‐year record of these four animals is summarized, with an emphasis on demographic, behavioural and medical observations.
Can predators regulate wild Rabbit Oryctolagus cuniculus population density in England and Wales?
Authors: TROUT R. C. , TITTENSOR A. M. 
Published: April 2008

ABSTRACTPredation has usually been interpreted as being a compensatory mortality factor, removing only the doomed surplus. The literature on the wild Rabbit Oryctolagus cuniculus L. is reviewed to collate counter‐evidence for a regulating influence of predation. This evidence is almost entirely circumstantial, not experimental. Predation has been reported to extend the length of time Rabbit populations remain low following a significant reduction of Rabbits by some other agent. Rabbit populations have been shown to increase very rapidly when predator density has suddenly been reduced. It has been suggested that predators affect the spread and dispersion of Rabbits both at the geographical and local levels. Predation has not, however, been shown to have an important influence at high Rabbit densities. Thus, its role can be that of a limiting factor rather than a density‐dependent regulatory mortality factor.The concept of predator pressure is presented and discussed, pointing out that there is currently no standard technique used for its measurement.Further evidence on the importance of predation is presented from four recent studies in England and Wales that relate, by association, the distribution and abundance of local Rabbit populations to the local attitude towards predators. Rabbits were found to be significantly more widespread and abundant where predators were removed (not restricted to keepered game estates) or at low density, than when predators were undisturbed or at a high density. The significance of these results is discussed.The circumstantial and corroborative evidence leads strongly to the conclusion that predator pressure can act as an additive rather than compensatory mortality factor in some circumstances, and can thus be a potential regulating factor. Predation is more likely to be a limiting factor at low Rabbit density however, since a density‐dependent relationship has not been demonstrated throughout the range of Rabbit densities that occur. This requires experimental demonstration to determine the threshold pressure below which predation becomes limiting. If so, reductions in Rabbit populations by short‐term control operations could allow natural predation to help maintain low Rabbit densities for several years in some habitats. Conversely, the implications for Rabbit populations and thus crop damage resulting from predator control (e.g. in game management regimes) should be appreciated.
A biological basis for bat conservation in British woodlands–a review
Authors: MAYLE BRENDA A. 
Published: April 2008

AbstractFifteen species of insectivorous bats are resident in Britain. The numbers of most species have declined drastically in recent years and all are now fully protected under the Countryside and Wildlife Act 1981. Forests and woodlands offer foraging and roosting habitats for all species and it is important for Forest Managers to be aware of the impact which management practices may have on bat populations. Current knowledge on the importance of woodlands for roosting, feeding, water and breeding is reviewed and initial management guidelines for the enhancement of forests for bats proposed. Future research needs are discussed.
The impact of predation by birds on bat populations in the British Isles
Authors: SPEAKMAN J. R. 
Published: April 2008

AbstractThe role played by predation of birds in the mortality of British bats is assessed. A review of dietary studies and anecdotal accounts revealed eleven species of bird which occasionally feed on bats–Herring GullLarus argentatus, Black‐headed GullLarus ridibundus, RookCorvus frugilegus, Carrion CrowCorvus corone, Little OwlAthene noctua, Short‐eared OwlAsio flammeus, KestrelFalco tinnunculus, HobbyFalco subbuteo, MerlinFalco columbarius, PeregrineFalco peregrinusand SparrowhawkAccipiter nisus.A further three species feed more frequently on bats–Barn OwlTyto alba, Tawny OwlStrix alucoand Long‐eared OwlAsio otus.Rates of predation were very low accounting for only 00034ooof items taken by small hawks and falcons (nitems = 29 519) but 0035o, of prey taken by owls (nitems = 99 479). By multiplying together the average annual prey capture rates of the predators, assessed from their energetic food requirements and direct observations of prey intake rates, the British populations of the predators and the contribution to the diet made by bats, the annual number of bats which die each year as a result of predation was estimated. The total losses of bats to predation might amount to about 201 400 bats/annum. The most significant predators are Tawny Owl (c.168 850 bats/annum), Barn Owl (c. 8800 bats/ annum), Long‐eared Owl (c. 10 200 bats/annum) and Kestrels (c. 8400 bats/annum). This predation by avian predators would account for about 11 % of the annual mortality of British bats. An assessment of the biases involved in this calculation suggests it is probably a minimum estimate. Despite the apparent low representation of bats in the diets of predatory birds, the effects of this predation on bat behaviour and population dynamics cannot be ignored.
Collecting mammalian tissue and data for genetic studies
Authors: SHERWIN WILLIAM B. 
Published: April 2008

AbstractIt is now recognized that genetic data have an important role in the management of wild and captive populations. Valuable samples and data can often be obtained when animals are handled for other reasons, but unless the personnel involved are aware of the correct procedures, the sample taken will probably be useless. This article outlines appropriate procedures, and the data that can be obtained from them, so that when an opportunity arises, a quick decision can be made about feasibility of sampling and the usefulness of the data for management or research. This paper does not cover the veterinary aspects of obtaining the sample, nor its laboratory analysis, which are assumed to be well understood by the donor and recipient organizations, respectively. Every attempt has been made to develop techniques which are simple, and allow storage of the sample while arrangements are made with a suitable recipient laboratory.
An analysis of some of the factors affecting the current distribution of Badger Meles meles setts in Essex
Authors: SKINNER CHRISTINE , SKINNER PAUL , HARRIS STEPHEN 
Published: April 2008

AbstractAll the known Badger setts in Essex were resurveyed in the mid‐1980s to record any changes in Badger distribution and status, and any associated changes in habitat and land use, during the preceding 20 years. New setts were also located. Being on the edge of London, Essex has undergone many recent changes that might be disadvantageous to Badgers. It is subjected to a high demand for land to meet increasing housing needs, intensive arable farming is widespread and few undisturbed habitats remain. These are typical of the pressures facing the Badger population in many areas of north‐west Europe, and so Essex was an ideal area in which to look at the status of the Badger, and in particular the impact of human activities on a Badger population. Much of the county is unsuitable for sett construction, since it consists of London Clay and glacial tills, and the highest concentration of setts was found in the Bagshot Beds. Woodland is rare in Essex, but it was still the favoured site for sett construction. Although over half the county is devoted to arable farming, Badgers tended to avoid such areas, and also avoided close proximity to roads, particularly busy roads, for sett sites. Since much of the county is low‐lying, man‐made embankments were particularly important sett sites, and land‐reclamation activities have probably provided additional sites for Badger setts. The effects of human activities on Badger distribution and numbers in Essex are discussed.
The biology of cementum increments (with an archaeological application)
Authors: LIEBERMAN DANIEL E. , MEADOW RICHARD H. 
Published: April 2008

AbstractCementum, a bone‐like tissue that surrounds the roots of teeth, anchoring them to the periodontal ligament, is useful for determining the age at and season of death of mammals, an issue of concern for both archaeologists and biologists. When a tooth is sectioned and examined microscopically, cementum appears in bands that differ in their optical properties and are well correlated with seasonal growth. Because it is a continually deposited tissue that is rarely modified or resorbed, cementum records the history of a variety of seasonal factors that affect its growth. An understanding of the biological nature of cementum is crucial to the identification of these factors and interpretation of the resulting incremental structure. This paper outlines current knowledge of the development, histology and function of cementum in the context of the mammalian masticatory apparatus. Of the various types of cementum, acellular cementum is often more appropriate for seasonal correlations. Differences between acellular cementum increments are probably related to specific dietary factors that often vary between seasons. Cellular cementum increments probably result from phasic cementogenesis triggered by tooth eruption. This paper outlines a study of cementum bands in Gazella gazella for which there is an excellent correlation between the season of death and incremental structures in their cementum. This correlation can be used to estimate the season of death of gazelles from archaeological sites in the Levant. Problems for future research are outlined.
Microtine ultradian rhythm of activity: an evaluation of different hypotheses on the triggering mechanism
Authors: HALLE STEFAN , STENSETH NILS CHR. 
Published: April 2008

AbstractUltradian activity rhythms are a peculiar behavioural pattern, in which the 24‐h day is divided into several short‐term activity cycles. Such patterns are particularly prominent in microtine rodents. In this paper we review experimental findings and proposed hypotheses on the proximate triggering mechanism of ultradian rhythmicity. Eight different mechanisms (classified as homeostatic, pacemaker and stochastic hypotheses) were analysed within the same theoretical model‐framework, considering feeding, food processing, energy turnover and activity behaviour.Ultradian activity patterns could consistently be generated by each of the analysed models. None of the models, however, resulted in frequency dependencies in respect to body weight, metabolic rate, food quality and food deprivation, unless additional assumptions were introduced.From our model evaluations we concluded that the stochastic model does not represent an independent hypothesis. Hence, only homeostatic and pacemaker hypotheses remained as alternative approaches to the triggering mechanism. Although the pacemaker hypothesis appeared more reasonable, a combination with some feedback mechanism to metabolism seemed even more likely. Some key experiments are suggested, which could give insight into the complex mechanism.