The home range and movements of the quokka Setonix brachyurus, a medium-sized macropodid marsupial, were investigated using radio telemetry. Fifty-eight quokkas from five remnant mainland populations in the northern jarrah (Eucalyptus marginata) forest of Western Australia were radio-collared and monitored for up to 2 years between 1998 and 2000. Mean (±SE) home-range sizes were 6.39±0.77 ha and core ranges averaged 1.21±0.12 ha. Male core home ranges were larger than those of females although not when corrected for body mass. Nocturnal ranges were larger than diurnal owing to nocturnal departures from the swamp. Ranges shifted to the edge of swamps in winter, as the swamps became inundated following rain, and toward the centre in autumn as the swamps dried. Quokka populations are thought to exist below carrying capacity at all sites and this probably caused the lack of dispersal observed in this study. We hypothesize that predation is suppressing population booms which would otherwise drive dispersal and thereby maintain metapopulation dynamics. Without dispersal to rescue unpopulated patches, we conclude that the original quokka metapopulation has collapsed and ameliatory measures are required.

It is generally accepted that predation by wolves Canis lupus is one of the major factors limiting densities of woodland caribou Rangifer tarandus caribou in North America. Conversely, little is known about the role of European wild forest reindeer R. t. fennicus as wolf prey, or about the influence of wolf predation on populations of this rare subspecies. This relationship was examined in east-central Finland, where wild forest reindeer coexist with moose Alces alces at a numerical ratio of c. 1 reindeer to 1.5 moose. During the study, moose were clearly the primary prey of wolves. Reindeer were, however, an important part of wolf diet in summer, autumn and early winter, when their remains comprised roughly 20–50% of all food items identified in wolf scats. Wolves exhibited a slight preference for reindeer over moose as prey during early winter (November–December) when the reindeer were moving towards their wintering ranges. Virtually no reindeer were killed by wolves during midwinter (January–March). This held also for a pack whose territory was located in the middle of the wintering range of reindeer, where reindeer outnumbered moose during the winter months. After the approximate ratio of wolves to reindeer increased from 0.004 (1998) to 0.02 (2000), wolf predation became the most common source of mortality (50%) for reindeer. The annual net increase in the reindeer population decreased from 13% to 7% because of increased wolf predation. The results indicate that wolf predation was an important factor limiting reindeer population growth. Wolves were, however, unable to prevent entirely the number of reindeer from increasing, partly owing to behavioural traits used by reindeer during winter and calving times.

The age of 86 individuals derived from groups of female sperm whale Physeter macrocephalus involved in three mass strandings on the north and west coasts of Tasmania in 1998 was determined from the number of dentinal growth layer groups in the teeth of individuals. Dorsal total lengths were also measured. Ages of females ranged from 0.75 to 64 years, with the majority (77%) aged between 20 and 45 years. Total lengths of female sperm whales ranged from 417–1200 cm, with 68% of females 1050–1200 cm long. Constraints associated with the age structure observed in this study and the representativeness of the age structure to that of the greater population are discussed. In an effort to assess the effects of underestimation of age estimates on age-specific demographic parameters, a model simulating changes in age structure as a result of tooth wear was developed and the resulting survival rates compared to those derived from the original age structures of the samples. Survival did not change significantly between the modelled and original age structures. Also, the survival rate calculated from Australian mature female sperm whales was compared to that calculated from sperm whales caught in whaling operations from Japanese waters. Australian mature female sperm whales demonstrated significantly higher survival rates (mean=0.905±0.046 SD range: 0.856–0.986) than mature females from Japanese waters (mean=0.885±0.034 SD; range=0.859–0.970), possibly the reflection of higher fishing mortality on the Japanese whales. Growth equations using Gompertz and von Bertalanffy models were calculated for female Australian sperm whales and compared. Both models described growth in female sperm whales similarly. Changes in the demographic parameters of sperm whales with the cessation of whaling may be reflected in the growth rates of individuals and as such, these equations may provide a useful tool for monitoring continuing changes in the demographic parameters of this species. Without long-term mark–recapture studies on sperm whales in this region, the frequent stranding of sperm whales in south-eastern Australia provides an important opportunity to collect data on the life history and demography of this species.

The dynamics of leopard seal Hydrurga leptonyx abundance and residency were investigated both within and between years at Bird Island, South Georgia, using observations of tagged and untagged individuals. Seals belonged to an open population, and were sampled outside the breeding season and during their northward winter dispersal (April–October). Seals at Bird Island were highly transient (41–63%) with only a limited number of individuals making repeat visits across years. A minimum yearly survival for resident seals was estimated to be between 0.61 and 0.85. The physical environment played an important role in leopard seal abundance, with observations following an apparent 4-year periodicity consistent with the frequency and timing of the Antarctic Circumpolar Wave. Years of low sea-surface temperature (SST) and extensive pack-ice corresponded to a higher number of seals present, earlier arrivals, and longer periods of residency. Peak leopard seal arrivals at Bird Island corresponded to periods of low SST, which was consistent with the pagophilic nature of this species.

The Namaqua dune mole-rat Bathyergus janetta breeds seasonally, producing up to two litters during the early summer in the Cape. Females exhibit elevated urinary progesterone and oestradiol-17β concentrations and males raised concentrations of testosterone, these correlate with the onset of the seasonal winter rainfall. The rains moisten the soil allowing excavation and provide the mole-rats with the opportunity not only to extend burrow systems but also to search for mates. An increased incidence of hindfoot drumming and visitations to neighbouring burrow systems occurs during this period. Plural occupancy of burrows by adult mole-rats was found during the onset of the winter, and pups, lactating and pregnant females were caught at the end of October and November (early Cape summer). Pups develop rapidly and their eyes open after c. 1 week. Pup body mass increases exponentially from birth to about 70 days. Inter-sibling aggression increases progressively and after c. 60 days captive-born pups had to be separated, suggesting that in the wild they would have dispersed.

Recent studies have revealed that calcium limitation of avian reproduction may be a widespread phenomenon, affecting both egg properties and chick development. The effect of calcium shortage on the final body size of fledglings is usually rather weak, possibly owing to compensatory growth. Achieving full skeletal size is not, however, a reliable indication of complete ossification and it is possible that chicks with similar tarsus lengths are in different stages of skeletal development. We hypothesized that measuring plasma activity of the bone alkaline phosphatase (ALP), a highly specific marker for bone calcification, may reveal subtle developmental differences in full-grown fledglings, having experienced different levels of calcium availability during growth. In two seasons, a number of pairs of great tit Parus major were provided with calcium-rich material during the nestling period, while others were not supplemented (controls). While no significant differences in size of fledglings were detected between groups, bone-ALP activity at the pre-fledging stage was lower in the calcium-provided nestlings than in the control nestlings. This may indicate that supplemented chicks had completed the rapid phase of bone formation, but this process was delayed in controls. Measuring ALP as a marker of skeletal development expands our knowledge of how delayed skeletal development of chicks can result in protraction of the nestling period, thereby reducing the breeding success of adult birds.

The Iberian Peninsula comprises two distinct biogeographic areas: a temperate Atlantic Eurosiberian (north) and a Mediterranean (centre and south), and they provide very different biotopes, landscapes and prey for carnivores. One example is an abundance of the wild rabbit Orytolagus cuniculus in the Mediterranean zone, which contrasts with the Eurosiberian zone, where the rabbit is scarce. The feeding resource partitioning among four sympatric predators (red fox Vulpes vulpes, wild cat Felis silvestris, genet Genetta genetta and stone marten Martes foina) was analysed in the Peneda-Gerês National Park (north-west Portugal), located in the Eurosiberian region. Data on the spatial distribution of three important prey species (Apodemus sylvaticus, Microtus lusitanicus and Talpa occidentalis) were also collected to investigate their possible relationships with the feeding habits of each predator. Rodents are the staple prey for this guild of carnivores. Predators are able to supplement their diets with one or two secondary prey types: rabbits and arthropods by the largest carnivores (the red fox and the wild cat); insectivores by the small predators (the genet and the stone marten). These results contrast with the characteristic Mediterranean predator–prey features, where rabbits are the main support of carnivore communities. The feeding resource partitioning revealed a complex structure characterized by a dynamic niche differentiation and overlap, according to a seasonal pattern. To explain this pattern of resource exploitation two hypotheses are discussed in the light of the body size of predators and their use of space.

Maximum likelihood (ML) and Bayesian inference (BI) analyses of the complete nucleotide sequences of the cytochrome b gene (cytb) were used to examine the phylogenetic position of the rare snake Xenophidionschaeferi within the alethinophidian snakes. The cytochrome b sequence of this representative of the poorly known family Xenophiidae was compared with those of a large and comprehensive suite of alethinophidian taxa. The research presented here represents the first time all families of alethinophidian and caenophidian snakes have been included in a single molecular phylogenetic study. Results from ML and BI analyses suggest a possible sister taxon relationship between Xenophidion schaeferi and the Bolyeridae. Moreover, strong statistical support also indicates that Xenophiidae is a member of a clade that contains Pythonidae, Loxocemidae, Uropeltidae, Xenopeltidae and Bolyeriidae. Additionally, maximum parsimony and BI analyses of previously published morphological data revealed that these anatomical character states and potentially low taxonomic sampling produced little phylogenetic information valuable to understanding the relationship of Xenophiidae among the Alethinophidia.

Habitat use by the boto, or Amazon river dolphin Inia geoffrensis, was investigated in and around the Mamirauá Reserve, Brazil. Largely forested with numerous channels and lakes, Mamirauá comprises a variety of seasonal floodplain habitats known collectively as várzea. The annual cycle of flooding in this region (amplitude 11–15 m) dominates all life. Profound seasonal differences in dolphin density between habitats were consistent with known fish movements, in turn dictated by changes in water level and dissolved oxygen. An exodus of botos from floodplain to river at low water prevents dolphins being trapped in areas that become entirely dry. Densities of botos in floodplain channels were seasonally higher (up to 18 km−2) than reported for any cetacean worldwide. Adults were largely segregated by sex except at low water. Females and calves dominated in chavascal habitat–the areas most remote from rivers, which were preferred by males. Probable causes of this segregation are the energetic requirements of calves and the safety of females and/or calves from male harassment. Some 80% of botos occurring on rivers were within 150 m of the margins. The reliance of adult females and calves on várzea in a region with exceptional dolphin densities demonstrates the importance of floodplain habitats for the boto, and may be the key determinant of this species‘ distribution.

Aristiform spines of the rodents Niviventer fulvescens, Maxomys surifer, Hoplomys gymnurus and 17 species of Proechimys (representing both recognized subgenera and all nine species groups) were studied qualitatively using scanning electron microscopy (SEM) and quantitatively by measuring seven linear dimensions. SEM was used to examine spine tips, bases, longitudinal furrows and cross sections. Spines of the murid rodents N. fulvescens and M. surifer differed from those of the echimyid rodents H. gymnurus and Proechimys spp. in possessing a smaller base with a longer, narrower neck, scaled rather than ridged longitudinal furrows, and a solid internal core and large lacunae at the spine margins. Spines of H. gymnurus differed from those of Proechimys spp. in being considerably more robust with a stout neck at the base, an abruptly-tapering tip and a dense inner layer with a series of smaller lacunae at the spine margins. A factor analysis of spine measurements revealed major differences among N. fulvescens, M. surifer, H. gymnurus, the Proechimys subgenus Trinomys and the nine Proechimys species groups within the subgenus Proechimys. However, all Proechimys species groups clustered closely together. A discriminant function analysis of the nine Proechimys species groups provided generally limited discriminatory power. Although spines are distinct at the generic and subgeneric levels, spines may possess limited diagnostic structure at the level of species within the subgenus Proechimys.

Secondary flightlessness has evolved independently many times in birds. Morphological changes in the pectoral girdle and flight feathers and changes in body size have been associated with the evolution of flightlessness, and it has also been suggested that flightless birds have relatively small brains. We therefore tested whether flightlessness is related to changes in relative brain size. Relative brain size was compared between volant and flightless species using both conventional statistics and modern comparative methods within nine taxonomic groups. No significant difference was found between flightless and volant species in six of these groups, regardless of whether body mass or tibiotarsal measurements were used as estimates of body size. Species with relatively smaller brains compared with their volant relatives were the great auk Pinguinus impennis, the kakapo Strigops habroptilus and some species of penguin. Thus, we found no evidence of a general correlation between the evolution of secondary flightlessness and the evolution of relatively small brains in birds. This suggests that neural requirements are not significantly different between flightless and volant species, although our methods may have overlooked subtle neurological changes that do not result in markedly different endocranial volumes.