The grasping behaviour, locomotion and substrate use of the tree shrews Tupaia minor and T. tana were investigated in the Department of Zoological Research at the National Zoological Park in Washington, DC. Seven arboreal T. minor and five terrestrial T. tana were observed and videotaped for 10-min focal animal samples totalling 77 h of observation. Locomotion and substrate use were scored and images of grasping behaviour were captured from videotapes. Tupaia minor individuals were videotaped crossing dowels and the number of dowel crossings that included grasps were scored. In 84% of dowel crossings, T. minor individuals used either their hallux or their pollex to grasp the dowels. Tupaia minor was also more active, moved more quickly, was more arboreal, rooted less, reversed its feet more, flexed its forelimbs more and was more semi-plantigrade than T. tana. It is proposed that arboreal tupaiids, such as Ptilocercus lowii and T. minor, may represent better models for early primates than didelphid marsupials because they are capable of grasping and are more closely related to primates.

Forty-six female black rhino were immobilized 113 times in the Sinamatella Intensive Protection Zone, Zimbabwe, from August 1992 to October 1997. The effects of immobilization on inter-calving interval (ICI), calving rate (calves/female/year), conception and calves born/year were assessed. The mean ICI (n = 17) was 40.24 ± 4.96 months. There was a significant linear relationship between the number and interval of immobilizations in the preconception interval (PCI) and duration of ICI; further investigations were made to overcome possible effects of temporal autocorrelation. Both a non-linear model and a general linear model (with five independent effects) showed a significant relationship only between the ICI and mean immobilization interval in the pre-conception interval (PCI), but not the mean immobilization interval in the whole ICI (including gestation immobilizations). Both suggested that the relationship between immobilization and inter-calving interval was not the result of temporal autocorrelation and that the immobilization regime significantly affected the ICI. Using the calving rate as a response variable, five effects were tested in a general linear model. Only the immobilization rate in the PCI was significant. For conceptions per calendar month, we examined two effects in a general linear model: the number of mature females immobilized each month, and rainfall in the month of conception plus 2 previous months. Both effects were significant. For the number of calves born/year, the effect of the immobilization regime (the number of mature females immobilized/year) and rainfall were examined. Only immobilization was significant. We suggest that the unusually intensive immobilization regime undertaken at Sinamatella has negatively impacted on female fertility, and discuss possible mechanisms. We also suggest the need to adopt guidelines to minimize the impact of immobilization on fertility in female black rhino.

The importance of interactions between sharks and cetaceans has been a subject of much conjecture, but few studies have addressed these interactions. Sharks (order Selachii) have been hypothesized to be important predators on dolphins and porpoises (suborder Odontoceti). Unfortunately, there are often few data to back up claims that certain shark species are major threats to cetaceans. To help identify potential shark predators in specific locations, available data on interactions with odontocetes for all shark species that may include cetaceans in their diet are reviewed. Shark species are categorized into groups based on predatory interactions with dolphins and porpoises (regular predators, occasional predators, potential predators, ectoparasites and insufficient data). Several shark species that have been overlooked in the cetacean literature are identified as potentially important predators while others that have been suspected to be important predators are probably at most occasional predators. How shark predation can influence dolphin populations, habitat use, group size and behaviour is discussed. How risk of shark predation can vary with habitat attributes in both nearshore and pelagic waters is also discussed. Predator–prey interactions have been the focus of most studies of shark–dolphin interaction, but competitive interactions may also occur. The first analysis of shark–dolphin dietary overlap is presented, which shows it to be significant between common dolphins and several species of sharks, including species that prey upon these dolphins.

Several species of crabs belonging to the family Ocypodidae are burrowers; they inhabit tropical sandy and muddy shores, including mangrove swamps, exposed to extreme conditions of intertidal areas. Dotilla fenestrata, the only East African representative of the subfamily Scopimerinae, exhibits high flexibility in its burrowing activity. Only part of the population has an exclusively burrow-orientated activity, whereas most individuals form dense aggregations or droves, that during the phase of diurnal low water move away from the normal distribution zone. Burrows are built according to two different architectural designs, the feeding-trench burrow and the igloo, which then constitute their territory. A resident will lose a contest for the burrow when the attacker is larger. When the ground is uncovered at low tide, emergence can be delayed or even fail to occur, and some crabs remain buried during the entire low water period. Only 50% of crabs remain faithful to the original burrow, while the others either leave it to occupy an empty one or dig a new burrow, or join the wandering drove. The spatial distribution of burrows from the high water neap level (our reference point) to the sea, differs during both spring and neap tides, and both diurnal and nocturnal tides. The differences may be due partly to the change of physical conditions, such as drainage and substrate grade (although within a mangrove swamp these do not follow a consistent gradient), but mostly may be related to the trade-off between the benefits and costs of living at different intertidal levels. With its burrowing and feeding activity leading to the re-deposition of excavated and pseudofaecal pellets, Dotilla plays a role as a sediment mover in this very specialized habitat. The results obtained from this study are compared with those reported in other ocypodids.

The social organization of the kinkajou Potos flavus is described from 380 h of observations on habituated, free-ranging animals. Individuals were most often alone while feeding at night, yet they regularly interacted in stable social groups. Four social groups were observed, each consisting of a single adult female, two adult males, one sub-adult and one juvenile. At least one breeding female was solitary and did not reside within a group. Social groups were consolidated primarily at denning sites and large fruiting trees by group feeding, allogrooming and scent marking. However, kinkajous were most often observed solitarily, as social feeding only occurred in 19.6 of total feeding bouts (mainly among males) and individuals rarely travelled together. Although the composition of social groups was polyandrous, males also copulated with non-group females which suggests a promiscuous mating system. Female-biased dispersal and patterns of male association seem to be patrilineal and based on resource defence. The evolution of social organization in the kinkajou is discussed in relation to predation risk, resource availability, and convergence with primates of similar fission–fusion socioecology.

Foraging flocks of red-billed choughs (Pyrrhocorax pyrrhocorax) were studied in the Gran Sasso National Park (Apennines, Central Italy) to assess the relevance of neighbour distance and group size upon vigilance, after controlling for other confounding variables (feeding frequency, air temperature and time of the day). Both partial correlation and multiple regression analyses clearly suggested that neighbour distance was the major determinant of the vigilant behaviour in the red-billed chough, even though group size would also exert a certain influence. As no significant correlation between the two variables was found, it can be assumed that the relationship between vigilance and neighbour distance is not spurious. Feeding frequencies were not significantly correlated with the other variables, except for temperature, for which a positive correlation was observed. Since the red-billed chough usually feeds on insects, which become more active and available as temperature increases, we suggest that the feeding frequency of the red-billed chough mostly depends on food availability. Our results are discussed in the framework of the hypotheses put forward to explain vigilance behaviour. The conclusion is that the ‘individual risk hypothesis’ explains the behaviour of the red-billed chough better than the ‘many eyes hypothesis’.

The diet of shy albatrosses Thalassarche cauta at Albatross Island, Tasmania, was examined quantitatively from 1995 to 1998. Two main sample types were examined: (1) whole stomach contents from chicks that had recently died of natural causes; (2) samples of fresh food delivered to chicks by their parents. Fresh food samples were considered most representative of the overall diet composition and, throughout the study, they were predominated by fish (89% by wet mass). Cephalopods, tunicates and crustaceans contributed 10%, < 0.1% and < 0.1% by wet mass, respectively, to the diet. There was little indication of seasonal or inter-annual variation in prey selection, as the composition of the diet was relatively constant through time. Fish from 16 species or families were identified, however, pelagic schooling Jack mackerel Trachurus declivis and redbait Emmelichthys nitidus together accounted for 57% and 80% (by number) of the fish identified in the stomach and fresh food samples, respectively. Cephalopods from 16 species or families were also identified, and here a single species (Gould's squid Nototodarus gouldi), accounted for 66% and 84% (by number) of the cephalopods identified. Both salps Pyrosoma spp. and crustaceans (largely Australian krill Nyctiphanes australis) contributed little by mass, but they occurred frequently and sometimes they accounted for a significant number of the prey items identified. Aspects of the biology and behaviour of the albatrosses and their main prey species combine to indicate that shy albatrosses have a largely predatory foraging nature. Much of their prey can be captured live, at the surface, during the day.

We studied the influence of moonlight upon the foraging activity pattern of the fruit bat Cynopterus sphinx. We observed the bats when foraging on the fruits of Calophyllum inophyllum and on the leaves of Mimusops elengi and Cassia fistula for 31, 27 and 28 days, respectively at the botanical garden in the Madurai Kamaraj University campus. The number of feeding bouts was recorded every hour between 18:00 and 05:00. A feeding bout involves a bat landing on the tree and collecting a part (or whole) of the fruit or a leaf. The total number of feeding bouts was negatively correlated with per cent moonlight each night. The number of feeding bouts decreased during the waxing phases of the moon. During the period of new moon the mean number of feeding bouts was significantly higher compared to the periods of other phases. During the first quarter and the last quarter phases, feeding occurred more during the dark part of the night, especially when the bats foraged upon M. elengi and C. fistula. While cloud cover enhanced the foraging activity, lightning and thunder suppressed it. Our study indicates that moonlight influences the foraging activity of C. sphinx.

The diet of the Irish hare Lepus timidus hibernicus was investigated in Northern Ireland. Faecal pellets were collected at regular intervals from three contrasting study sites and from a number of randomly selected sites from known land classes. Microhistological techniques were employed to analyse the pellets. Grass species occurred in high percentage frequencies in all samples of faecal pellets and a wide variety of plant species were represented (up to 26 species in one study site). In a stratified, random survey of the presence of hares, areas of lowland intensive agriculture had fewer positive records than expected. It is contended that L. t. hibernicus may not be able to sustain viable populations in areas of intensive agriculture, which are almost exclusively composed of ryegrass Lolium spp.

We examined data on captive multi-mammate mice (Mastomys coucha) to assess differential maternal investment, and sex-specific resource allocation. Differences in maternal size were induced through manipulation of dietary protein in three treatment groups: low (10%), medium (15%) and high (20%) protein diets. Mothers on the 20% protein diet were significantly larger than those on the lower protein diets, and produced significantly more male than female offspring. Mothers on the lower protein diets did not produce sex-biased litters. There were no sex-specific differences in body size or body tissue composition of pups at birth or at weaning within each treatment group. At weaning, pups in the 20% protein treatment group had proportionately greater amounts of lean tissue and less body lipid reserves than pups in the 10% protein treatment group. Pups in the 20% protein treatment group were also larger, and had faster growth rates, than those in the 10% protein treatment group. Weaned pups in the 15% protein treatment group had the fastest growth rates and greatest energetic reserves of all of the treatment groups. Our results suggest that larger mothers on the high (20%) protein diet show differential investment in the sexes, not by allocating more resources to individuals of that sex, but by producing more male than female offspring.

Evidence for signal coding for attributes such as age, sex or population of origin, was sought in odour profiles derived from natural secretions of the preorbital gland of red deer Cervus elaphus (n = 26), sika deer C. nippon (15), Chinese muntjac Muntiacus reevesi (23) and Chinese water deer Hydropotes inermis (53); from metatarsal secretions from red deer (n = 35), sika (30), fallow (193) and roe deer Capreolus capreolus (26); and from roe deer interdigital glands (n = 48). Volatiles were eluted from sample materials at body temperature, to restrict analysis to those elements which would occur within the natural odour profile; the different volatile elements were then separated by gas chromatography. Initial results of these analyses were strongly suggestive of some level of signal-coding for attributes of the signaller. Few secretions (species × gland) contained many volatiles which differed significantly between deer from different populations of origin and, except in the muntjac preorbital and sika deer metatarsal secretions, separation of populations was generally rather poor in formal discriminant function analyses (DFA). However, where no constraint is imposed on the number of volatiles allowed to enter the analysis, secretions from at least one gland accurately discriminated between the sexes in the original sample for most species; separation of sexes was only ineffective for Chinese water deer and fallow deer. Discrimination between deer of different age-classes was similarly effective in the original sample for red deer preorbital and roe deer metatarsal secretions and fair for preobital secretions of Chinese water deer; unbalanced age-structure of samples did not permit analysis for muntjac or sika deer. Sometimes the actual predictive power of discrimination was poor; it is notable that this was characteristically associated with small sample sizes and the evidence indicates that scent secretions from most species sampled here offer the potential for coding for at least the sex and age of the signaller. Although chromatographic analysis of odours from some glands reveals consistent differences between odour profiles characteristic of sex, age or population, this does not imply that the signal is deliberately coding for such information, or that the deer use the information available. It is possible that differences in the composition of secretions in relation to age or sex of the signaller, for example, is coincidental or of secondary significance.

Most naked mole-rats Heterocephalus glaber are countershaded, with purple-grey dorsal but pale pink ventral skin. The exceptions to this coloration pattern are uniformly pink, and include newborn pups, most queens and breeding males, and very old animals. Countershading begins to appear at 2–3 weeks of age and begins to disappear at c. 7 years of age. Countershading may provide camouflage when young naked mole-rats are above ground attempting to disperse. Therefore, reproductives and older workers may lose this coloration once they are unlikely to leave the burrow. Alternative hypotheses for pigmentation that we considered include: thermoregulation, and protection from abrasion or from damaging ultraviolet radiation. These hypotheses are not necessarily mutually exclusive, but do lead to different predictions regarding the development of pigmentation and which colony members should be countershaded.

At the end of the 1970s otter surveys were developed to study the distribution of the Eurasian otter Lutra lutra. The method was quickly adopted and expanded to include other species of otter. Different methods to estimate otter density were also used. There is some uncertainty, however, as to the significance and precision of the results. Otter surveys, radio-tracking studies and otter censuses (tracks and visual) were conducted in the same areas simultaneously. Comparison of the home ranges of otters tagged with transmitters with the results from otter surveys carried out in the same areas showed very similar otter distribution. Some 71% of those sites examined in which only one otter lived were positive, and 97% of those sites with two or more otters. Differences were found between different watercourses. In small or average sites with waterways, one single otter was capable of marking many kilometres so that it could be detected in most of the conventional 600 m sites (here 71% of sites). The data obtained by radio-tracking showed that almost all otters can be seen by experienced observers, confirming the validity of visual censuses. A high correlation was found between the number of otters seen during visual censuses and the number of otters detected by means of the length of their footprints. Using new and old tracks (2-days-old or more) the number of otters was overestimated.

Population dynamics, breeding patterns and spatial use of the garden dormouse Eliomys quercinus were studied for 3 years in a larch woodland in the Alps. Animals were caught with live-traps, once a month from May to September, and marked with transponder tags. Population density ranged from a minimum of 8.3 individuals/10 ha to a maximum of 49.4 individuals/10 ha when juveniles became trappable. The activity season of the garden dormouse lasts 5 months and allows the animals to reproduce only once a year. Birth rates fell between the middle of June and the middle of August. The dormouse population was characterized by high stability and adults continued to live in the same area from year to year. The main factor limiting the survival of individuals was winter mortality. Survival on the trapping grid through hibernation was 36–50% for adults and c. 32% for juveniles. During the mating season, males and females were aggregated and overlapped their ranges, and after the mating season, they spread out. The tendency of the reproductive females to have separate non-overlapping ranges is indicative of a probable territorial behaviour in females during gestation and lactation.

In Zimbabwe the incidence of reported jackal rabies varies predictably over the year with peaks during June to August (cold dry season) and December to May (wet season), and may be explained by the social behaviour of jackals. June to August is the mating season, at which time home ranges increase in size, and overlap between species and neighbouring conspecifics is greater. Intra-group concordance in range use decreases in association with the social stress caused by mating and mate guarding, and young adults use peripheral areas, perhaps increasing contact with neighbouring jackals. Dispersal is most likely to occur in the mating season. These factors increase the contact rate between neighbours and, therefore, rabies incidence. In the hot dry season (the whelping season), home ranges decrease in size, and the overlap of interspecific and neighbouring conspecific ranges decreases. Concordance in range use of intra-group conspecifics increases and activity focuses on the den; inter-group contact rate therefore decreases, as does rabies incidence. The addition of juveniles to the population in the wet season increases jackal density and thus contact rate and also coincides with a high rabies incidence. Taking these factors into account, we suggest that the control of jackal rabies by oral vaccination should focus on the period before the mating season and after the whelping season.

The Italian hare (Lepus corsicanus De Winton, 1898), formerly considered a subspecies of the European brown hare (L. europaeus Pallas, 1778), is an endemic species recently revalidated by genetic analyses. We performed univariate and multivariate analyses to assess morphological discrimination between L. corsicanus and L. europaeus. A clear morphological discrimination in body and skull measurements between Italian hares and European hares was evident. Our results are consistent with the morphological observations in the historical specimens and with mtDNA data. Furthermore, no morphological hybrid was found even in areas where viable populations of the two species coexist in sympatry. Despite the original distribution of the Italian hare, it is impossible to determine a clear boundary between the two species because of human introduction of L. europaeus for hunting. Populations of L. corsicanus have been recorded from central Italy to Sicily, with a fragmented distribution and sometimes in sympatry and syntopy with populations of L. europaeus. However, in Sicily the Italian hare is continuously distributed, locally abundant and no stable European hare populations have been found. Although the conservation of the Italian hare needs to be understood better, urgent conservation and management strategies are required to avoid the threat of extinction for local populations.

Fifty radio-tagged long-tailed bats Chalinolobus tuberculatus, belonging to three social groups numbering on average 72–132 bats each, ranged over an area of 11 700 ha in Nothofagus rainforest in the Eglinton Valley, Fiordland, New Zealand, during the austral summers of 1993–96. Bats were followed for 12.7 ± 6.3 (sd) days. Home-range sizes were among the largest published for Microchiroptera. Median minimum convex polygons (100% MCPs) for adult males were 1589 ha (max = 5629 ha), 1361 ha for post-lactating females, and 657 ha for non-reproductive females. Ranges of lactating females (median = 330 ha), were significantly smaller. Juveniles that were volant for < 2 weeks had the smallest ranges (median = 237 ha) but movements increased significantly after c. 2 weeks to a median of 2006 ha. Movements were frequent and rapid within the range (790 ± 471 sd m/15 min) and average range lengths were 3.3–10.9 km (max = 19 km). Despite their large home ranges, bats concentrated their activity (85% of fixes) in small core areas that represented a mean of 5.7 ± 1.5% (sd) of the 100% MCPs. Ranges of roosting sites were also small, averaging 9.4 ± 1.8% (sd) of total range size. Bats followed similar movement patterns each night but core areas only overlapped by 43 ± 14% (sd) from one night to the next. Moderately low levels of overlap of home ranges (31–68%) and of core areas (23–56%) among individuals of the same reproductive class suggest a degree of spatial segregation among bats from the same roosting group. A prediction that C. tuberculatus has large ranges to minimize overlap between foraging bats, reflecting scarcity of food, requires testing. Range sizes were probably underestimates of seasonal, annual, and life-time range requirements. Nevertheless, large range size and the degree of individual spacing implies that conservation areas designed for bats should be large and that protection of roosting areas alone would not be sufficient to protect bat populations.

The lungs of the naked mole-rat Heterocephalus glaber were morphologically (qualitatively) and morphometrically (quantitatively) investigated in adult captive in-burrow body-temperature-maintained (CBTMA) and captive cold-exposed animals (CCEA). The observations were compared with those of field (burrow-dwelling) animals (FA) examined in an earlier study. The lungs of the captive animals were morphologically (qualitatively) similar to those of the field mole-rats. Conspicuous paedomorphic features, i.e. a preponderant double pulmonary capillary arrangement, incomplete differentiation of alveolar pneumocytes, and extension of a cuboidal epithelium to the immediate vicinity of the alveoli, were observed. The prevalent pulmonary underdevelopment was attributed to the relatively low metabolic rate of the poikilothermic naked mole-rat, a species that has evolved in a thermally stable environment. Measurable differences and similarities were found between the lungs of the captive naked mole-rats themselves (i.e. the CBTMA and the CCEA) and between the captive and the field ones. Genetic factors may help explain the conserved pulmonary structural features while environmental (gaseous) change from a hypoxic–hypercapneic (an oxygen deficient–high carbon dioxide concentration) to a normoxic–normocapnic atmosphere and the thermal shift respectively may have enforced pulmonary transformations between the CBTMA and the FA and between the CCEA and the CBTMA. Paradoxically, the CCEA had a significantly lower mass-specific total morphometric pulmonary diffusing capacity of 0.024 compared with that of 0.102 mlO2.s−1.mbar−1.kg−1 in the CBTMA. The observed morphometric differences indicate that the lung of the naked mole-rat, though morphologically unchanged, is intrinsically tractable to environmental shifts in its habitat. Studies on captive naked mole-rats should not be indiscriminately taken to be representative of the species.

Genetic variability in three species of Pimelodidae catfish (Iheringichthys labrosus, Pimelodus maculatus and Pimelodus cf. absconditus), collected at four sites in the Tibagi river-basin: Sertaneja, Londrina (lower Tibagi), Sapopema (middle Tibagi) and Tibagi (upper Tibagi) was analysed using RAPD and isoenzymatic techniques. Iheringichthys labrosus had the greatest genetic variability showing a proportion of mean polymorphic loci (P¯m) of 53.7%. The dendrogram showed that the individuals from the locations were clustered together, supporting the hypothesis that I. labrosus has a sedentary or localized geographical distribution. Pimelodus maculatus is the only species studied that is considered to be highly migratory. The P¯m obtained for this species was 30.2%. Their genetic dendrogram showed that the individuals were not clustered, based on the place of collection. P. cf. absconditus had a P¯m value of 47.4%, and the external morphology of this species is similar to that of I. labrosus, which hindered differentiation of individuals from the two species. RAPD and isoenzyme analysis, however, provided differential patterns for P. cf. absconditus from I. labrosus.

Distributions of flying-fox (Pteropus alecto and P. scapulatus) were examined in relation to use of habitat in the essentially natural landscape of northern Australia. There were differences between the species in terms of the vegetation used for roosting and foraging, which were related to the reproductive cycle and seasonal variation in temperature, rainfall and the availability of preferred foods. Important habitats of P. alecto varied seasonally and included floodplain, mangrove, monsoon rainforest, Melaleuca open-forest, and Eucalyptus miniata/E. tetrodonta open-forest and woodland. The minimum scale at which conservation of P. alecto should be attempted is in the order of 5000 km2, based on seasonal patterns of habitat use. The size of this area will make conservation via traditional reserves difficult and conservation of important habitats outside reserves will be needed. Habitats protected for the benefit of P. alecto will also benefit P. scapulatus but because P. scapulatus is more mobile, displays greater yearly variation in distribution and is less well understood than P. alecto, appropriate conservation actions are less certain.