Reproduction and postnatal development of the southern African bush Karoo rat Otomys unisulcatus was studied in the laboratory. Fifty-one litters were obtained from 17 pairs, with a mean litter size of 2.09, reproductive effort of 0.58 and gestation period of 37 days. Neonates weighed 6.1–9.6 g and were semi-precocial. Weaning began as early as 8 days of age, and the age at first reproduction was 6 weeks in males and 5 weeks in females. Compared to its congeners, O. unisulcatus has small litters of semi-precocial young which undergo rapid postnatal development, and contrary to expectations displays several K-selected reproductive characteristics. The reproductive biology and postnatal development of the bush Karoo appears to reflect a compromise between exploiting sporadically abundant resources and the occupation of stick lodges, which may provide a favourable microclimate to buffer the harsh external climate.

Allozyme and morphometric variation was studied in two populations of moles, Talpa europaea and T. romana, in an area of sympatric occurrence (Palazzo, near Assisi, central Italy) located along the known parapatric contact boundary. The electrophoretic analysis revealed 36 moles characterized by a genome of T. europaea, and 29 moles with a genome of T. romana. The extension of the overlap zone was c. 2 km along the north–south direction. Fourteen specimens recognized as T. europaea had an Ada allele typical of T. romana, while two specimens identified as T. romana were characterized by two alleles (at the Adh and Sdh loci) previously found only in T. europaea. The skulls of the specimens with introgressed alleles showed features intermediate between those typical of T. romana and T. europaea. However, the intermediate skull shape of the introgressed specimens did not correspond to an intermediate size between T. romana and T. europaea. The occurrence of individuals with introgressed alleles, and the lack of F1 hybrids or backcrossed individuals suggest that at present free interbreeding between the two species is unlikely, but that hybridization and backcrossing has occurred, probably when the species first came into contact.

The ability of two species of African insectivorous bats (Angola free-tailed Mops condylurus and little free-tailed Chaerephon pumilus) to distinguish between males and females and roostmates from strangers in scent-choice experiments was tested. Both sexes of M. condylurus and male C. pumilus discriminated between sexes based on odours collected from the interaural and muzzle glandular areas, whereas female C. pumilus did not show any preference in either trials. Female M. condylurus from intermediate sized colonies (c. 200–600 individuals) distinguished female roostmates from strangers. There is some indication that roostmate recognition may vary inversely with the colony size of the test-subject suggesting that recognition is individually based, but further studies are necessary to determine if this is so. Histological work revealed that the interaural and muzzle area contain sebaceous glands and that the quantity of the glandular tissue is sexually dimorphic in both species for the interaural area, with males having more tissue, but not for the muzzle area. The presence of osmetrichia using SEM was also observed in the interaural area of both sexes of M. condylurus and in male C. pumilus. Their presence and association with sebaceous glands, as well as the results of the scent-choice experiments are indirect evidences of use of chemical signals, possibly pheromones, by these bats.

Satellite telemetry was used to identify the foraging distributions of three congeneric species of albatrosses that nest in the tropics/subtropics. Breeding waved albatrosses Phoebastria irrorata from the Galápagos Islands travelled to the productive upwelling near the Peruvian coast and nearby areas during the rearing period in 1996. Black-footed albatrosses P. nigripes and Laysan albatrosses P. immutabilis nesting in the Hawaiian Islands and tracked during the 1997–98 and 1998–99 breeding seasons also performed long foraging trips, to continental shelf areas of North America. In both years, breeding black-footed albatrosses made long trips to the west coast of North America (British Columbia to California). In 1997–98, breeding Laysan albatrosses travelled primarily to the north of the Hawaiian Islands and reached the waters of the Aleutian Islands and the Gulf of Alaska. In 1998–99, Laysan albatrosses had a complete breeding failure, and no long trips by breeders were tracked as a result. These three species mixed short and long trips during the chick-rearing period, but not the brooding period nor incubation period. Waved albatrosses made only long trips during the incubation period. Analysis of movement patterns showed that the core feeding areas during long trips were located over the continental shelves of North and South America. The data on foraging biology of these species have implications for assessing bycatch risk in commercial fisheries.

The taxonomy and distribution of cephalochlamydid cestodes are reviewed. This group is primarily specific to pipid anurans and occurs naturally across sub-Saharan Africa. Paracephalochlamys gen. nov. has two large lateral testes (sometimes doubled or absent on one side) on the anterior margin of each segment, while Cephalochlamys Blanchard, 1908 has three to 23 small testes scattered in lateral fields. Paracephalochlamys papilionis sp. nov. infects Pseudhymenochirus merlini in Sierra Leone. The distribution of Cephalochlamys species is inferred from the previous literature and numerous new records. Cephalochlamys namaquensis (Cohn, 1906) occurs in Xenopus laevis laevis in Namibia, South Africa, Lesotho and Zimbabwe, X. l. poweri (new host record) in Zambia and the Democratic Republic of Congo (D.R.C.), X. l. victorianus in Kenya, Uganda, Rwanda and D.R.C., X. l. sudanensis (new host record) in Cameroon and Sudan, and the ranid anuran, Rana angolensis, in Zimbabwe. Anthropogenic dispersal of C. namaquensis, together with X. l. laevis, has occurred to localities in the south-western United States and Isle of Wight, U.K. Cephalochlamys compactus sp. nov., differentiated from C. namaquensis by a less well developed median ovarian cavity and more compact vitellarium, occurs in Xenopus muelleri in Togo, Ghana, Nigeria, Cameroon, D.R.C., Zimbabwe and South Africa, X. borealis in Kenya, X. clivii in Ethiopia, R. angolensis in Ethiopia and R. occipitalis in Nigeria. Cephalochlamys representatives of uncertain specific status have been recorded in X. gilli (new host record) in South Africa, X. pygmaeus and X. fraseri-like hosts (new host records) in the D.R.C., X. tropicalis (new host record) in Nigeria and R. occipitalis in Gabon. Despite the ability of some species to infect distantly related amphibians, the distribution of cephalochlamydid taxa amongst their principal hosts, pipids, can be related to the allopolyploid evolution of this anuran family.

Tropical seabirds have evolved a wide range of breeding regimes to fit with their local environment. The western Indian Ocean shows various oceanic situations, providing opportunities to link variations in breeding phenology with variations of the environment. The breeding seasons of seabirds at Europa Island (Mozambique Channel, western Indian Ocean) are analysed. Three oceanic, tuna-associated species (the sooty tern Sterna fuscata, the red-footed booby Sula sula, and Audubon's shearwater Puffinus lherminieri) breed during austral winter (June–October), whereas the red-tailed tropicbird Phaethon rubricauda breeds during austral summer (November–April). During winter, sea-surface temperatures are the lowest, subtropical waters are the closest to the island, and long-line catches of tunas are important. Thermal fronts occur during winter, in relation to the northward shift of subtropical waters. This is known to be favourable to tunas, and I suggest that the winter breeding of sooty terns, red-footed boobies and Audubon's shearwaters is because of an increase in the abundance of tunas. Geographic variations in the breeding phenology of sooty terns in the western Indian Ocean largely support the hypothesis that sooty terns take advantage of cool subtropical waters, when those waters are within their foraging range. The red-tailed tropicbird is a solitary forager, not associated with tunas. During the chick-rearing period, 40% of the mass of food brought to the chicks consists of dolphin-fishes Coryphaena spp. Those warm water, surface dwelling fishes are known to migrate in relation to sea-surface temperatures. Seasonal changes in the occurrence or vulnerability of dolphin-fish in the Mozambique Channel may have favoured a summer breeding regime in red-tailed tropicbirds at Europa Island. Further studies of the marine life of seabirds are needed to test these hypotheses and to learn more about the foraging ecology of tropical seabirds.

The aquatic or web-footed tenrec Limnogale mergulus is a semi-aquatic lipotyphlan insectivore known only from stream habitats of eastern Madagascar. Limnogale is considered a high conservation priority because of its rarity, suspected vulnerability to habitat degradation, and unique ecological niche on the island. However, its ecology and behaviour remain poorly understood. Quantitative faecal analysis and radio-tracking were used to study the diet and foraging activity of Limnogale in eastern Madagascar. Faecal pellet counts along forest and zero-canopy streams were also conducted to examine the response of aquatic tenrec populations to catchment deforestation. Faecal analysis indicated that the diet of Limnogale consists mainly of larval and adult aquatic insects, larval anurans and crayfishes. The most important prey were Ephemeroptera, Odonata and Trichoptera larvae. Diets did not differ substantially between forest and zero-canopy streams. Radio-tracking of two individuals indicated that Limnogale is strictly nocturnal and remains in streamside burrows during daylight. Nocturnal movement was restricted solely to stream channels and consisted of active foraging by swimming and diving. Distance travelled per night ranged from 200 to 1550 m along the stream channel (means 1067 and 860 m, respectively). The total lengths of stream channel used by the two aquatic tenrecs during each radio-tracking study were 1160 and 505 m, respectively. Faecal pellet counts along forest and zero-canopy streams suggested that Limnogale was at least as abundant in zero-canopy streams. This finding suggests that Limnogale is not an obligate forest species; however, it preys on benthic communities that are extremely vulnerable to sedimentation. Control of excessive sedimentation and maintenance of healthy benthic communities are essential to Limnogale conservation. We include an updated list of known sites for Limnogale and recommend the use of faecal pellet surveys to assess the current distribution of the species.

The pecten oculi is a highly vascularized and pigmented organ that overlies the optic disc and projects into the vitreous body in the avian eye. First reported over 300 years ago, its function(s) remains a puzzle to ornithologists, ophthalmologists and anatomists. Morphometric study of this unique organ was undertaken in birds exhibiting apparently different visual acuities, namely two species of diurnal birds (the ground-dwelling domestic fowl Gallus gallus var. domesticus and a highly active predator bird, the black kite (Milvus migrans) and a nocturnal bird (the spotted-eagle owl Bubo bubo africanus). The volume of the owl's eye was 4.8 and 2.2 times larger than that of the fowl and the kite, respectively. However, the pecten of the fowl consisted of more pleats (16–18) compared to the kite (12–13) and the owl (5–6). The volume of the pecten of the kite was 1.4 and 2.7 times larger than that of the fowl and the owl, respectively (P < 0.05). Similarly, the surface area of the pecten of the kite was 2.6 and 4 times larger than that of the fowl and owl, respectively (P < 0.05). The volume density of blood vessels (lumen and wall) in the pecten of the kite, fowl and owl comprised 67.7%, 66.9% and 62.6%, respectively, the pigmented tissue constituting the rest. Both the volume density and the volume of the blood in the pecten were higher in the diurnal birds (kite, fowl) than the owl (P < 0.05). The surface area of the capillary luminal surface was 1.7 and 5.3 times higher in the kite than in the fowl and the owl, respectively (P < 0.05). These results suggest that the functional morphology of the pecten correlates with the life-style of the bird and with functional need, and lends further support to the nutritive role of the pecten.

The Neotropical pitviper genus Bothrops comprises about 40 species, which occur in all main ecosystems of cis-Andean South America. We explored the relationships of body size and form (tail length and stoutness) with macrohabitat use in 20 forms of Bothrops. Semi-arboreal habits appeared only in forest forms. Semi-arboreals are significantly more slender and have longer tails than terrestrials; body size is not significantly different between terrestrials and semi-arboreals. Within Bothrops, independent contrasts for macrohabitat use were significantly correlated with contrasts of tail size (positively) and stoutness (negatively); thus, the more arboreal the species, the longer its tail and the more slender its body. Contrasts of adult body size seems to remain constant over the lower range of macrohabitat use, but to decrease in species of Bothrops which are more arboreal. Reconstructions of character states indicate that: (1) the ancestor of Bothrops was a small, stout, terrestrial species; (2) semi-arboreal habits appeared one to three times in the genus; (3) a decrease in stoutness and an increase in tail length occurred along with an increase in arboreality in some clades. Although macrohabitat use seems to be important in determining body form in Bothrops, our results also indicate that tail size, stoutness and body size may also be affected by selective agents other than macrohabitat use. The selective agents responsible for the shifts in macrohabitat use in Bothrops are still uncertain, although they may have included prey availability and/or predation pressure. The plasticity of macrohabitat use, morphology and body size described in this study may have been key features that facilitated the highly successful ecological diversification of Bothrops in South America.

Analysis of 141 scats of maned wolf Chrysocyon brachyurus collected in a region of upland forest and meadows of south-eastern Brazil yielded 351 food items in the wet season (60 scats) and 407 in the dry season (81 scats). Scarabaeidae and rodents were the most frequent animal food in both seasons, complemented by birds in the wet season and unidentified mammals in the dry season. Seeds revealed Solanum lycocarpum to be the most frequent plant food in the dry season and an Annonaceae and a Cactaceae the most frequent in the wet season. A total of 33 seed morphospecies were retrieved. Although our results reveal some shared and some divergent trends from dietary studies undertaken in savanna (‘cerrado’) areas, we found a very high frequency of potentially harmful tourists' garbage. This highlights the necessity for better environmental education and confirms that the maned wolf is a generalist and opportunist omnivore.

We describe the age structures of two neighbouring terrestrial salamander populations. The skeletochronological method was also used on larvae in utero and on new-born individuals. The age of adults was 8–24 years in population A, while males reached maturity at 3–5 years old and the youngest females were 6 years old in population B. Males and females from population B were also larger than those in population A. For the first time, lines of arrested growth (LAGs) were also found in the humerus of intra-uterine larvae and new-born individuals, indicating that young can spend up to 3 years in utero (population B) and up to 4 years (population A) before hatching. Growth of adults (fitted by the Bertalanffy model) also exhibited differences in growth coefficient (k) and mean asymptotic length (SVLmax) between sexes and populations. Local climatic conditions differed between the two areas of these populations and we hypothesize that the number of rainy days directly influences foraging during the short period of activity (< 3 months), leading to a delay in age at maturity, smaller length and growth rate, and increased gestation duration in the drier environment. The discussion is focused on proximate environmental influences on the variation of length and associated life-history traits in ectotherms, especially in terrestrial salamanders.

The compactness of bone tissue was measured in the shaft of the femur, tibia and fibula in 390 male and female Nile monitors Varanus niloticus from three distinct regions of Sahelian Africa. In males, bone compactness increases during ontogeny in the three bones. Conversely, in females, it tends to decrease in the femur and, to a lesser extent, the tibia, but not in the fibula. In addition to this long-term trend, gravid females have lower femoral compactness than mature non-gravid ones. Moreover, important differences are noticeable between local samples, indicating that the variation in bone compactness during ontogeny is a flexible or even a facultative process. Histological observations reveal the existence of an extensive remodelling by resorption and reconstruction on the walls of the marrow cavity in the femur and tibia, and the complete absence of Haversian substitution. It is concluded from these data that: (1) during ovogenesis, female Nile monitors recycle skeletal calcium through cortical resorption in certain bones, if the calcium supply from food is not enough; (2) this remodelling process is not balanced, which creates a long-term tendency towards a deficit in reconstructive bone, and a consecutive decrease in the compactness of the skeletal elements involved. The comparative and functional aspects of these results are discussed.

We studied the postnatal body weight gain and development of 11 male and nine female giant panda Ailuropoda melanoleuca cubs born at Beijing Zoo from 1985 to 1998. Growth rates of the cubs appeared to be sexually dimorphic from the fourth month after birth; the male grew slightly faster than the female cubs. Growth rates between artificially fed and naturally fed cubs were significantly different from the fourth month after birth. The growth rate of the artificially fed cubs was slightly higher than that of the cubs fed by their mothers, indicating that the substitute milk satisfied the nutrient needs of the cubs. The body length of the cubs increased rapidly after birth; 8-month-old cubs were three times longer than newborn cubs. Chest circumferences of 8-month-old cubs also increased to twice that of newborn cubs. Tail length relative to body length was reduced from 14.9% at birth to about 8.6% in 8-month-old cubs. Cubs started to grow teeth when they were 3 months old. By the age of 1 year, the cubs had fully grown deciduous teeth. The teeth formula of one 1-year-old cub was 2·1·3·0/2·1·3·0=24. We recorded the changes in fur colour, development of the sense organs and limbs of the giant panda cubs. Finally, we compared the body weight and life-history parameters of giant pandas with those of bears and raccoons and discussed the management regime for the care of captive-born giant panda cubs.

Lactating New Zealand sea lions (Phocarctos hookeri) have recently been reported to be the longest and deepest-diving otariid. An unusually large proportion of dives exceeded a theoretical aerobic dive limit, predicted from estimated oxygen stores and measurements of diving metabolic rate. We investigated swimming speed, a key variable in both the management of oxygen stores and foraging strategies, and its relation to diving behaviour in New Zealand sea lions. Diving behaviour was nearly continuous with short inter-dive intervals. Mean diving swimming speeds ranged from 1.6 to 2.4 m/s. Mean surface swimming speeds ranged from 0.9 to 1.8 m/s and were significantly lower than diving speeds in all subjects. New Zealand sea lions spend significant but variable amounts of time resting at the surface. Diving and swimming speed patterns were consistent with foraging on the benthos. Time in the foraging zone was maintained in deeper dives by increasing dive duration. This increased duration cannot be accounted for by a decreased metabolic rate resulting from slower swimming speeds, as speeds increased with the maximum depth of dives. Patterns of swimming speed and acceleration suggest the use of a gliding phase during descent. For most females, the extended duration of deeper dives did not impact on surface times, suggesting the use of aerobic metabolism. Females exhibited significantly slower swim speeds during the bottom segments of foraging dives than during descent or ascent. These findings suggest that swimming behaviour should be considered a critical component when modelling energetic costs for diving animals.

A feral population of African clawed frogs Xenopus laevis from a small pond in South Wales was sampled continuously for 2 years to assess morphometric growth. Toe-clips taken at intervals over a 4-year period were found to contain lines of arrested growth (LAG) which corresponded to each consecutive winter. The first toe-clips revealed a population structure within the pond consisting of a dominant cohort of frogs with one LAG that metamorphosed in 1993, and a few older individuals. Subsequent toe-clips in 1996 and 1998 gave two and four more LAG, respectively. Morphometric growth was found to be restricted to a short growing season, significant differences in the growth rates of males and females being first detected in their third growth season. Reproductively active frogs were still within their initial period of growth, suggesting that Xenopus laevis does not conform to the standard energy resource allocation mechanisms of typical ectotherms.