bluuebunny/crossref_metadata_2025 huggingface dataset:
Foods and foraging behaviour of Red (Sciurus vulgaris) and Grey (Sciurus carolinensis) squirrels
Authors: MOLLER H.
Published: April 2008

Red squirrels occur most commonly in conifer habitats where their basic year round diet is conifer seed, supplemented by seed, berries and fruits of deciduous species when available. Conifer buds and shoots are important foods in winter and spring, as are flowers in late spring and early summer. Fungi are eaten throughout the year but mostly in autumn. Grey squirrels occur most commonly in hardwood forests where their primary food is nuts and samaras of deciduous trees and shrubs. Buds, shoots and flowers are substituted in spring and early summer, along with a variety of coarse plant and animal foods in summer. Both species prefer seed, so other plant foods predominate in the diet only in places or times when seed crops are small. Seeds of the same species are used by both Red and Grey squirrels when and where available but there have been no quantitative studies of diet of both species in closely similar habitats, so food preferences within the range of foods used by both species are unknown.

Squirrels have strong preferences for particular food species, trees within a species and even between individual seeds and buds within each tree. Diet varies between individuals and between sex and age groups within squirrel populations. The determinants of these food preferences remain unknown, despite natural advantages of squirrels for testing foraging models.
Reproductive physiology of the Grey squirrel (Sciurus carolinenis)
Authors: WEBLEY G. E. , JOHNSON ELIZABETH
Published: April 2008

The Grey squirrel shows two peaks of litter production in spring and summer, but this does not necessarily mean that all female squirrels have two litters per year. Captive female squirrels do not show regular oestrous cycles, and there is evidence that both the presence of a male and adequate space is necesssary for the induction of oestrus. After day sixteen of gestation, the ovaries are not necessary for the maintenance of gestation. Our studies indicate that the male Grey squirrel has a seasonal period of t esticular regression in the autumn, which may be short‐lived so that full breeding condition is attained by December In some years, localized populations of Grey squirrels may have a prolonged period of testicular regression throughout the winter, with a consequent absence of spring breeding, and there is some evidence that this may be related to available food.
The causes of damage by Red and Grey squirrels
Authors: KENWARD R. E.
Published: April 2008

Squirrels cause damage by competing with man for nuts, fruit or grain crops, by competing for food with animals favoured by man, by gnawing human constructions and by stripping bark from trees grown for timber. Competition for food with man, game or livestock can best be prevented by excluding or destroying squirrels. Competition between Grey and Red squirrels in Britain is not yet understood, but the Grey squirrel may be more successful in deciduous woodland because it is better adapted to foraging there and for surviving food shortage than its congener. Gnawing power cables can be prevented by coating with glass beads as a repellant. The reasons for bark‐stripping are not clear, but it may well be triggered by food shortage, or possibly by agonistic behaviour, and the extent of damage may then be influenced by variation in the sap quality of the trees. Habitat management, to reduce the winter food supply for squirrels, and perhaps also to increase food availability during the summer damage period, may provide less costly control measures than killing squirrels.
Mammal Society dormouse survey, January 1975‐April 1979
Authors: HURRELL ELAINE , McINTOSH GILLIAN
Published: April 2008

The dormouse survey was initiated by the Mammal Society and ran from January 1975 to April 1979. The dormouse is very much a southern mammal in Britain with a reduced range compared to that found 100 years ago. There seems to have been a decline in population and possible reasons for this are discussed. The habitat favoured by dormice is considered; a thick secondary layer is very important with bramble forming a major component. Dormouse nests are most often found in bramble at an average height of just over a metre from the ground. Dormouse requirements, particularly for scrub, should be considered when areas for wildlife conservation are being managed.
Social behaviour and social organization of marsupials
Authors: RUSSELL ELEANOR M.
Published: April 2008

Detailed 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

The 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

This 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

Field 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

This 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.

In 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

Fluoride, 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

It 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

Data 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

Four 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

Predation 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

Fifteen 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

The 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

It 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

All 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

Cementum, 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

Ultradian 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.
Biology, conservation and status of the Amazonian Manatee Trichechus inunguis
Authors: ROSAS FERNANDO CÉSAR WEBER
Published: April 2008

The Amazonian Manatee Trichechus inunguis (Natterer, 1883) is the only exclusively freshwater sirenian and the smallest of the living species. Its inability to reduce peripheral heat loss limits its distribution to tropical waters. The species is endemic to the Amazonian region, being distributed throughout the Amazon basin, occurring mainly in calm waters and lakes. The species has been commercially exploited since 1542, with the meat and hide being the main products extracted. This commercial exploitation, combined with their very low reproductive rate, has seriously reduced the manatee population. Therefore the Amazonian Manatee is now considered an endangered species. Although it is protected by most of the countries where it occurs, there is no law enforcement, and the species is still captured throughout the Amazon. Data on general biology, physiology and management of the Amazonian Manatee, as well as its status and recommendations for its conservation, are presented.
Patterns of distribution in Japanese land mammals
Authors: DOBSON MIKE
Published: April 2008

Distribution patterns among the terrestrial mammal species of Sakhalin and the main islands of Japan are shown to fall into 12 clear groups. The most fundamental distributional break (Blakiston's Line) is that separating Hokkaido and Sakhalin to the north, with their boreal fauna typical of northern Eurasia, from ‘Hondo’ (Honshu, Shikoku, Kyushu) to the south, which demonstrates a high degree of endemism and supports a small number of Indo‐Malayan elements. Distribution patterns may be explained by considering the Quaternary geohistory of the area, particularly the formation of land bridges and the changes in climatic conditions during this period. A dynamic classification based upon origin of the fauna recognizes seven categories, although on evidence currently available the allocation of some species to categories is not yet possible.

Hondo underwent two main periods of land bridge connection to the Asiatic mainland. The first, prior to the Pleistocene, allowed immigration of forms which have since developed into distinctive elements of the endemic fauna (‘Old Hondo Endemics’). The second, during the Middle Pleistocene, brought in widespread Palaearctic species as well as components from South‐East Asia (‘Early Colonists’), some of which have since undergone vicariant speciation (‘New Hondo Endemics’); it also allowed several of the Old Hondo Endemics to extend their range to the mainland and Hokkaido (‘Expanding Hondo Endemics’).

Sakhalin and Hokkaido have been more intimately connected to the mainland (most recently until less than 10 000 years ago), such that endemism is very restricted. Species groups here are the ‘Late Colonists’, cold‐adapted tundra species which expanded with the glacial advances, but which are now restricted in distribution, and ‘Recent Colonists’, postglacial forest species which recolonized before the severance of land bridges. Moving the other way were ‘Expanding Northern Endemics’, which arose in Hokkaido or Sakhalin during the last glacial and colonized the adjacent mainland before severance of land links. There are, additionally, several possible Expanding Hondo Endemics in Hokkaido, although human intervention in determining their current distributions cannot be ruled out.

Bats, to which the sea barriers of the Japanese area are less complete, exhibit somewhat different patterns of distribution, confirming predictions about the role of even narrow marine straits in restricting ranges of nonflying mammals.
Distribution of the Forest Dormouse Dryomys nitedula (Pallas, 1779) (Rodentia, Myoxidae) in Europe
Authors: KRYŜTUFEK B. , VOHRALIK V.
Published: April 2008

A spot distribution map of Dryomys nitedula in Europe is presented, based on a critical evaluation of published information from the various countries of Europe. In addition, maps which are numbered to identify localities were prepared for regions where Dryomys nitedula distribution was largely unknown until now. The species has a unique distribution, ranging from the Alps in the west to the foothills of the Urals in the east, and from southern Latvia in the north as far south as Calabria and Peloponnisos. The species' reported vertical range is from sea level in the Balkans to the subalpine belt in the Alps. The presence of Dryomys nitedula in Europe can be traced back to the beginning of the Pleistocene, but its recent distributional area does not coincide with climatic factors, nor with the distribution of vegetation communities. Possible competition with Eliomys quercinus is discussed as a factor affecting the peripheral range distribution of Dryomys nitedula.
Life histories of Clethrionomys and Microtus (Microtinae)
Authors: INNES DUNCAN G.L. , MILLAR JOHN S.
Published: April 2008

Although there have been numerous life‐history reviews of mammals at high taxonomic levels (e.g. among families within orders), there are far fewer studies at lower taxonomic levels (e.g. among species within genera). Data on adult weights, litter size, gestation length, neonate weight, age and weight at weaning, growth rate to weaning, maximum life span, and length of the breeding season were compiled from the literature on five species of Clethrionomys and 33 species of Microtus. Variability in litter size and male body weights was not significantly different when compared between cyclic and non‐cyclic populations. Coefficients of variation were also calculated for the three species with the most data (C. gapperi, C. glareolus and M. pennsylvanicus). These values showed that the amount of intraspecific variation differed among traits as well as among species. Gestation length was the most invariable of all traits and variation in adult weights, neonate weight, gestation length, and litter size had similar values to those reported for Peromyscus maniculatus. Five and eight traits differed among Clethrionomys and Microtus species, respectively. Differences in litter size, adult weights and length of the breeding season were common to both genera. Male weight, gestation length and neonate weight as well as length of the breeding season were different between genera. Very few traits covaried within C. gapperi, C. glareolus or M. pennsylvanicus. Similarly, few traits covaried among all Clethrionomys populations. However, among all Microtus populations and Microtus species, 11 and 12 correlations were significant. Many of the patterns found in Microtus involved positive relationships between female weight and some other trait. These patterns have also been found by broader surveys at higher taxonomic levels. Large species of Microtus had larger offspring, a greater litter size and occurred in short‐season environments relative to small species of this genus.
The biology of Elephantulus brachyrhynchus in natural miombo woodland in Tanzania
Authors: LEIRS H. , VERHAGEN R. , VERHEYEN W. , PERRIN M.R.
Published: April 2008

Field expeditions between 1986 and 1989 yielded information about the distribution of macroscelids in Tanzania. The rare Elephantulus brachyrhynchus was captured in a natural habitat complex of miombo woodland, Combretum savanna and grassland in Dakawa, Tanzania. Basic ecological data for this species were obtained from 46 animals in a removal‐trapping study and 58 in a live‐trapping study.

Sex ratio was near to parity. There was no evidence of a restricted reproductive period, although pregnancy incidence was higher around January‐February. Litters in utero comprised one or two embryos. E. brachyrhynchus had a preference for the transitional Combretum savanna. Stomach contents analysis showed a remarkably high proportion of green plant material in the diet.
Use of space by the African Striped Ground Squirrel Xerus erythropus
Authors: LINN IAN , KEY GILLIAN
Published: April 2008

Five Striped Ground Squirrels Xerus erythropus were radio‐tracked at Katumani, Kenya, for periods of up to 10 days. The results were used to explore their short‐term use of space. Definitions of the terms ‘home range’ and ‘core’, and some aspects of the methodology of home‐range analysis are discussed. In an area of low‐productivity bushland, subject to intermittent drought, where their food supply was patchy and unpredictable, the squirrels travelled about 1.5 km per day, and occupied rather large home ranges averaging 12.4 ha. Levels of aggression between conspecifics was low, home ranges were not defended, and there was considerable range overlap. Nights were spent in burrows which were commonly shared with conspecifics. On most days a single relatively long exploratory excursion was made outside the home range, extending the average area of the total range to some 40 ha. Despite the presence of major environmental features which might have been expected to affect the squirrels' foraging behaviour, such as cultivated fields, home range use was very symmetrical, suggesting that essential resources (food, shade, burrows) were widely dispersed throughout the range. Squirrels foraged alone, harvesting small, scattered, high‐quality food items, mainly vegetable. Activity was interrupted from time to time to retire to the shade to lose heat, and a midday rest was taken. Only part of the home range was used each day. A variable degree of central concentration of activity could be observed. The squirrels' use of space enabled them to exploit available food resources opportunistically and efficiently, and made them difficult to control effectively.
Why are Dormice rare? A case study in conservation biology
Authors: BRIGHT P. W. , MORRIS P. A.
Published: April 2008

In the last 100 years, the Dormouse Muscardinus avellcmarius has disappeared from about half its geographical range in Britain. Evidence is presented which indicates that declining range and numbers are due to a complex interplay of factors which include fragmentation, deterioration and loss of specialized habitat. The Dormouse is unusual in being a relatively A‐selected small mammal, with exacting ecological requirements which render it very vulnerable, particularly to habitat fragmentation. The Dormouse is also sensitive to climate, both directly and probably indirectly through the effects of weather on the timing and abundance of food (insects, flowers and fruits). Combined with low population density and low intrinsic rate of population increase, this makes the Dormouse highly vulnerable, not just to absolute climatic measures (e.g. temperature, rainfall), but especially to climatic stochasticity, particularly at the edge of its range. There are strong associations between the distribution and changing status of the Dormouse and various climatic parameters, and clear parallels with other climate‐sensitive taxa, notably bats and butterflies.

The Dormouse is a very specialized species, highly sensitive to environmental change, resulting in its piecemeal, progressive extinction, particularly in northern counties. It is likely to be a very sensitive indicator species for monitoring future changing environments and an excellent model for studying the effects of habitat fragmentation, climatic shifts and climatic stochasticity.
Distribution of cetaceans in the offshore Gulf of Mexico
Authors: JEFFERSON T. A. , SCHIRO A. J.
Published: April 2008

In order to comprehend better the distribution of Gulf of Mexico cetaceans, all available records of whales and dolphins in the offshore Gulf were assembled and analysed. This included sightings, strandings and captures of all species, except the Bottlenose Dolphin Tursiops truncatus, from all sources, except the recently completed GulfCet project. An attempt was made to confirm species identification for each of the records. A total of 1223 records was available for analysis. Twentyseven species of cetaceans have been confirmed to occur in the offshore Gulf of Mexico. All of the baleen whales, with the possible exception of the Bryde's Whale Balaenoptera edeni appear to be extralimital in the Gulf. The Sperm Whale Physeter macrocephalus is, by far, the most common great whale in this body of water. All previous records of Common Dolphins Delphinus spp. in the Gulf are rejected as either incorrect or unreliable, and there is currently no convincing evidence that dolphins of the genus Delphinus occur in the Gulf. The Atlantic Spotted Dolphin Stenella frontalis is the only species, other than the Bottlenose Dolphin, that regularly occurs over the continental shelf. The Pantropical Spotted Dolphin Stenella attenuata is the most common species of small cetacean in oceanic waters of the Gulf, but many other species also occur there in significant numbers.
Review of cetaceans stranded on the Irish coast, 1901–95
Authors: BERROW SIMON D. , ROGAN EMER
Published: April 2008

Published records of cetaceans stranded on the Irish coast during the period 1901–95 are reviewed. In this review the number of stranding events has been used in the analysis and includes both live strandings and those animals washed up dead. There were 529 records involving 21 species. The Harbour Porpoise (27%) was the most frequently reported species, followed by Common Dolphins (16%) and Pilot Whales (15%). Minke Whales (8%) were the most frequently reported mysticete. The number of reported strandings has increased since the 1960s which is thought to be mainly due to increased observer effort. Cetaceans have stranded on all Irish coasts but mainly along the south coast and along the western seaboard but with no apparent overall seasonal trend. There was a peak in the strandings of Common Dolphins during 1991–92 when 27% (28 records) of all strandings were reported and of White‐sided Dolphins when 60% (28 records) were reported, both of which were attributed to possible interactions with fisheries. The number of Striped Dolphins stranded on the Irish coast has increased steadily since the 1980s and may reflect increasing water temperatures.

These stranding records are considered inadequate to determine the status of most species of cetaceans in Irish waters but are sufficient to identify unusual stranding events such as high mortalities due to fisheries interactions or epizootics. More observer coverage is required before the stranding data are adequate for monitoring the status of most species but a stranding scheme is considered the most effective and efficient method of long‐term monitoring of cetaceans in Irish waters.
The diets of British bats (Chiroptera)
Authors: VAUGHAN N.
Published: April 2008

Sixty‐one studies of the diets of 15 species of bats found in the British Isles are reviewed. Fourteen studies describe the diets of more than one species. Barbastella barbastellus and Plecotus spp. eat mainly Lepidoptera. Eptesicus serotinus takes mainly Coleoptera, but feeds on a wide range of prey, found in several habitats. Rhinolophus ferrumequinum hunts mainly Coleoptera and Lepidoptera by hawking, gleaning and perch hunting. Myotis bechsteinii takes mostly woodland families of Diptera and Lepidoptera. The remaining nine species eat mainly Diptera. Myotis nattereri feeds almost entirely on diurnal Diptera, gleaned from their nightly resting places. Rhinolophus hipposideros and Myotis mystacinus take mostly swarming crepuscular Diptera by hawking, probably near water and in damp wooded areas; both also glean. Myotis brandtii feeds on Diptera by hawking and gleaning; Nyctalus noctula by hawking. Myotis daubentonii, Pipistrellus spp. and Nyctalus leisleri eat many aquatic Diptera, and may therefore be expected to feed close to freshwater habitats. M. daubentonii hunts by trawling aquatic Diptera from the surface of water.
The history of the Eurasian Beaver Castor fiber in Scotland
Authors: KITCHENER A.C. , CONROY J.W.H.
Published: April 2008

In 1995 Scottish Natural Heritage proposed a feasibility study to examine the case for reintroducing the Eurasian Beaver Castor fiber to Scotland. Following IUCN guidelines, an important first step is to demonstrate that the Beaver was once a native of Scotland and that the causes of its extinction no longer pose any threat to reintroduced animals. Therefore, palaeontological, archaeological and historical evidence for the former existence of the Beaver in Scotland and the causes of its extinction are reviewed.

Palaeontological and archaeological evidence suggest that the Eurasian Beaver was once widely distributed throughout mainland Scotland. Historical evidence suggests that although it was once probably fairly common, it became extinct between the twelfth and sixteenth centuries, most probably towards the latter. The main cause of its decline and extinction was probably hunting for its pelt, meat and castoreum, but habitat destruction may have been important in the loss of some small isolated populations.

Given that the causes of extinction of the Beaver in Scotland now no longer exist or can be effectively controlled, there is no reason why a feasibility study cannot proceed to assess the practicalities of a reintroduction.
Trophic status and feeding habits of the European Polecat Mustela putorius L. 1758
Authors: LODÉ T.
Published: April 2008

The trophic status of the European Polecat Mustela putorius was studied through a review of the diets of 18 different populations in Europe. Rodents represented the principal prey in 10 sites (55.5%) and were a prey of secondary importance in seven sites (38.8%). Anurans prevailed in three sites (17%) but constituted the second food category in eight others (44%). The ascendant hierarchical classification showed a relatively unvarying diet in Europe. The frequency of birds and invertebrates were important in the diversification of the diet, indicated by the value of the food niche index, whereas rabbits were more significant in southern regions. The constant incidence of predation on woodland rodents and amphibians gave a particular status to the Polecat and showed it to be a generalist feeder well adapted to the mid‐European region.
Recent divergence with gene flow in Tennessee cave salamanders (Plethodontidae:Gyrinophilus) inferred from gene genealogies
Authors: NIEMILLER MATTHEW L. , FITZPATRICK BENJAMIN M. , MILLER BRIAN T.
Published: April 2008

Cave organisms occupy a special place in evolutionary biology because convergent morphologies of many species demonstrate repeatability in evolution even as they obscure phylogenetic relationships. The origin of specialized cave‐dwelling species also raises the issue of the relative importance of isolation vs. natural selection in speciation. Two alternative hypotheses describe the origin of subterranean species. The ‘climate‐relict’ model proposes allopatric speciation after populations of cold‐adapted species become stranded in caves due to climate change. The ‘adaptive‐shift’ model proposes parapatric speciation driven by divergent selection between subterranean and surface habitats. Our study of the Tennessee cave salamander complex shows that the three nominal forms (Gyrinophilus palleucus palleucus,G. p. necturoides, andG. gulolineatus) arose recently and are genealogically nested within the epigean (surface‐dwelling) species,G. porphyriticus. Short branch lengths and discordant gene trees were consistent with a complex history involving gene flow between diverging forms. Results of coalescent‐based analysis of the distribution of haplotypes among groups reject the allopatric speciation model and support continuous or recurrent genetic exchange during divergence. These results strongly favour the hypothesis that Tennessee cave salamanders originated from spring salamanders via divergence with gene flow.