Crytomys damarensis is a eusocial subterranean rodent occurring in colonies in which a sole reproductive female and one to two males are involved in procreation; the remaining colony members are non-reproductive. Within each sex the reproductive animals are usually the largest and most dominant animals.

The dominance hierarchy of a young colony consisting of a founding reproductive pair of genetically unrelated animals and the first three successive litters, comprising 12 offspring, from this pair had a non-linear dominance hierarchy, h = 0.32. Dominance was found to be correlated positively to body mass as well as to the age of the animal. A subsequent study, which followed the incorporation of two subsequent litters and growth of the first three litters, and comprised 15 offspring, revealed that the dominance hierarchy had attained linearity, h = 0.9. Dominance was again positively correlated with the age and body mass of respective colony members. In both studies there was no clear relationship between dominance and sex within the colony.

The relationship between body mass and burrow-maintenance activity revealed that frequent workers in the colony had a greater mean body mass than infrequent workers. It is suggested that in establishing colonies, the older, stronger and hence larger animals may constitute the initial workforce. In addition the colony exhibits frequency-related work determination into frequent and infrequent workers. Gender was found to play no role in the frequency of work associated with burrow maintenance.

The social organization and temporal changes with recruitment are discussed in the light of events occurring in the field.

Dragline use by an orb web spider (Nephila clavipes) was analysed by observing both intact spiders and those prevented from producing a dragline. The behaviours observed were those associated with returning to the web hub and prey capture. Upon returning to the hub, spiders resume the resting position by rotating within the hub, producing several new dragline attachment points during the rotation. The importance of the spider's use of the dragline was made clear by preventing experimental animals from producing the dragline. During resting, the permanent dragline-to-web attachment enabled the spider to maintain the correct posture. Prey capture behaviour was adversely affected in spiders prevented from using the dragline: without a dragline, all relevant components of the behaviour required more time to perform, and movements within the web (e.g. toward prey and back toward the hub) were directed less accurately. The benefit of the dragline to the spider, in terms of safety, time, energy and reduced exposure to predators, is likely to be significant.

Hair morphology has been studied and applied in several subjects, such as food quality control, archaeology, criminology, and ecology. Although medullar and scale patterns of hair structure are well known for a variety of mammal species, the effects of hazardous conditions on the internal and external morphology of hair are not known. In the present work, white-eared opossum (Didelphis albiventris) hairs were submitted to taxidermy, digestion, and putrefaction processes, and afterwards their structure was compared to control hairs, under the scanning electron microscope and light microscope. The results obtained indicate that the processes tested do not cause damage to the medullar and scale patterns of the opossum's hairs. In conclusion, based on the experiments with D. albiventris hairs, it is possible to compare hairs from museum collections or freshly collected hairs to hairs found in scats, gut contents, pellets, or other sources.

A radio-tracking study of two adjacent social groups of red foxes was conducted in a suburban residential district of greater Toronto from late July through December 1990. This was the first radio-tracking study of red foxes living completely within a large metropolitan centre in North America. The groups had non-overlapping home ranges and included both breeding and non-breeding adult females. Mean group home range size was 52 ha, toward the small end of home ranges documented for the species, and distances travelled nightly by adults of both sexes ranged from 2-20 km. The home ranges of both groups were primarily located in a bushy ravine containing golf courses and park land, but individual foxes readily utilized areas of low-density housing characterized by large, well-vegetated lots. However, the foxes avoided adjacent medium-density housing areas, indicating that this population may not be as habituated to urban life as some populations described from Great Britain and mainland Europe. Because of their constant proximity to, and frequent use of, some residential habitat types, these foxes have ample opportunity to transmit diseases such as rabies to domestic pets and humans in the vicinity.

The condition factor and fecundity of the translocated rock-dwelling cichlid fish, Cynotilapia afra, Pseudotropheus callainos, and Pseudotropheus tropheops ‘red cheek’ at Thumbi West Island, southern Lake Malawi, were compared with those at their sites of origin, in the north of the lake. The guiding hypothesis was that these species, having originated from a region of the lake which is generally poor in nutrients, and been introduced to an area richer in nutrients, would be in better condition and more fecund there than at their sites of origin. That seemed to be the case. P. callainos and P. tropheops ‘red cheek’ had significantly higher condition factors and fecundity indices at Thumbi West Island than at their sites of origin. However, both condition factor and fecundity of all the species studied fluctuated seasonally. The major peaks in condition factor coincided with either the wind-induced lake upwelling from June to August, or the rains. Major peaks in fecundity occurred at the end of the rainy season, between February and April, or at the end of the upwelling period between September and October. The translocated species began to breed at a smaller size at their sites of origin in the north than at Thumbi West Island, probably as an adaptive response to a poor nutrient regime in the north.

The increase in population of some translocated species can be partly attributed to their improved condition and fecundity due to enhanced nutrient availability at the site where they have been introduced. This may have negative implications for the native taxa, more particularly as competition for breeding space is rife among the rock-dwelling cichlids of Lake Malawi.

Larvae of Lepidoptera are mainly herbivores, and only the larval stages of Bradypodicola and Cryptoses pyralid moths are known to be specialized coprophages. Here, we report coprophagy as a main feeding habit for the larvae of another pyralid moth, Aglossa pinguinalis, on the basis of observational and experimental evidence. The larvae of this moth require two years to complete development, and construct silk tubes connecting the food source with a shelter chamber. Larvae of A. pinguinalis were mostly found inside caves, where they were about 700 times more abundant than in the open field. Inside the caves, observational results indicate that 98% of the larvae fed mostly on excrement and only 2% were recorded as eating other kinds of detritus (decayed mushrooms). No larvae were recorded eating plant detritus in the censuses nor in experimental detritus patches. The larvae did not show preferences for different types of excrement in the caves. Experimental dog and sheep excrement corroborated this result, showing that the abundance of larvae did not differ between these two excrement types over the entire study. We suggest that habitat selection of A. pinguinalis is ecologically similar to the trophic specialization of Bradypodicola and Cryptoses, in spite of the differences in natural history traits among these moths. Feeding on dry excrement inside caves, or in buried sloth dung, may reflect the constraints for Lepidoptera successfully to colonize excrement: in more exposed excrement, they cannot compete with other coprophagous specialists owing to the lack of parental care (e.g. resource relocation) and slow growth rates. We hypothesize that coprophagous Lepidoptera will be restricted to competition- and predation-free habitats and resources, feeding on excrement inside caves and animal burrows.

Analysis of 904 small carnivore scats collected over a two-year period in a seasonal forest in the south-western Central African Republic yielded the remains of 732 shrews, rodents (<1 kg), and bats comprising at least 34 species. Most scats belonged to the long-nosed mongoose, Herpestes naso, the numerically dominant carnivore in the study area. Shrews were the principal small mammal prey with respect to number of individuals and frequency of occurrence. The mean monthly frequency of occurrence of shrews was 21.7% and of small rodents (<100 g) was 20.8%. Both shrews and small rodents occurred significantly more often in scats collected during dry season months, and live-trapping of rodents over a 22-month period revealed similar peaks in availability. In contrast to many mammalian carnivores, shrews did not appear to be used as an alternative prey source: not only did consumption levels of both prey types fluctuate in synchrony, but the availability of rodents apparently had no effect upon the likelihood of including shrews in the diet. Preferential use of small mammals by long-nosed mongooses was tested for the 10 rodent species for which abundance indices were calculated. Mongooses preyed selectively on several rodent species (Praomys spp., Deomys ferrugineus, Stochomys longicaudatus, and Grammomys rutilans), while the most common rodent in the study area, Hylomyscus spp., was found in scats at lower frequencies than expected. In accordance with the habitat specificities of these ‘preferred’ rodent prey, it is suggested that mongooses and perhaps other small carnivores were foraging in micro-habitats characterized by higher-than-average vegetation understorey thickness where the simultaneous rate of encounter with arthropods, their main prey, and shrews was apt to be high.

Sexual segregation reported in many wild ruminants is generally assumed to result from either different habitat choices by adult males and females or ‘social factors’. In this framework, we studied group composition and habitat use of mouflon sheep (Ovis gmelini) over an annual cycle in the low-mountain range of Caroux-Espinouse (continental France). The analysis of group composition revealed segregation outside the rut, not only between the sexes, but also between the young (2-3 years) and old rams ([ges ] 4 years). Moreover, ewes, young rams, and old rams exhibited some differences in patterns of habitat use in the mid-rutting and lambing seasons, but showed similar patterns in winter and summer. These results, juxtaposed with those of studies of interactions and proximity between individuals within groups, suggest that segregation between age-sex classes has a strong social basis in mouflon sheep.

The social structure of three sympatric bat species occupying bat boxes in woodland in southern England was studied: Pipistrellus pipistrellus (pipistrelle), Plecotus auritus (brown long-eared bat) and Myotis nattereri (Natterer's bat). Before parturition, P. pipistrellus populations were heavily skewed towards solitary males. After parturition, the sex ratio was closer to unity. Recaptures of marked bats suggested that after parturition a resident male population of P. pipistrellus is invaded by a transient female population. The sex ratios of populations of P. auritus and M. nattereri were very close to unity, both pre- and post-parturition. The numbers of recaptures of individual bats were similar for both sexes in P. auritus and slightly higher for females in M. nattereri. In the mating season (August-October), solitary male P. pipistrellus were found with small groups (1-9) of females. In contrast, in both P. auritus and M. nattereri, mixed sex groups were found pre- and post-parturition, and roosting groups in the mating season contained up to 20 females and up to 10 males. The stability of female groups in P. auritus appeared to be higher than M. nattereri and P. pipistrellus as known females were found together more frequently. These patterns are discussed with reference to the possible differences in foraging and social behaviour.

The egg capsules and larvae of Engina armillata (Reeve) (Gastropoda: Buccinidae) are described for the first time. Its general ecology in the Cape d'Aguilar Marine Reserve, Hong Kong, is also described, the species occurring under stable boulders with a community of encrusting species, notably sedentary tubicolous polychaetes. The diet of E. armillata at Cape d'Aguilar consists of serpulid and spirobid polychaetes. Of the four commonest such species, Hydroides elegans was preferred to Pomatoleios kraussi, Simplicaria pseudomilitaris and Spirorbis foraminosus. Consumption rates by E. armillata varied considerably amongst individuals, but generally ranged between 1.2 and 6.5% of predator dry weight day-1 during conditions wherein prey quantity was maintained. Such a figure is low when compared to other boring naticid and muricid predatory gastropods which spend much time and energy accessing their prey. The ready availability of easily accessible prey may account for the low consumption rate of E. armillata (as also seen in other non-boring predatory gastropods) and explain its apparent specialist feeding habits.

Many life-history traits are allometrically tied to body size, in snakes as well as in other animals. Two problems with previous analyses on this topic for snakes are that: (i) the range of body sizes within species is generally small, so that most analyses have relied on interspecific comparisons; and (ii) available data have been heavily biased towards small, temperate-zone colubroid species. We test the generality of results from previous work with data on a species of giant tropical snake that is phylogenetically and ecologically distinctive, and encompasses such a massive size range that we can examine intraspecific allometries. We use data from >1,000 field-collected reticulated pythons from southern Sumatra to ask two questions: (i) do life-history traits show intraspecific allometries similar to those revealed by interspecific comparisons?; and (ii) are mean values for life-history traits in a giant snake consistent with allometric trends in smaller species? As predicted, strong intraspecific allometry was evident for most of the life-history traits we measured, including reproductive output (e.g. clutch size, frequency of reproduction in females, testis volume relative to body mass) and energy stores (relative size of the abdominal fat bodies). For many traits (e.g. the means and variances of clutch sizes and maternal body sizes, relative offspring size, body size at maturation relative to size at hatching and maximum adult size), these giant pythons were near or beyond the extremes reported for smaller species of snakes, supporting the importance of allometry. None the less, reticulated pythons deviate from many of these previously-documented allometries in significant ways, suggesting that current generalizations about life-history allometry in snakes may be premature.

Two species of tuco-tucos, Ctenomys talarum and C. australis, overlap geographically in south-eastern Buenos Aires Province, Argentina. C. talarum (100-180 g) occupies habitats with clayey and harder soils, while the larger C. australis (300-600 g) occupies sandy and quite friable soils. This study compares the digging apparatus and digging performance of both species, and also provides additional ecological data to describe the adaptations of both species. When confronted with sandy, friable soils, both tuco-tucos exclusively use their forelimbs (‘scratch digging’ mode) to break the soil. When confronted with harder and clayey soils, C. australis used its forelimbs and, less frequently, its incisors, but no appreciable effectiveness was observed in breaking the soil. On the other hand, C. talarum behaved as a ‘scratch’ and ‘chisel-tooth digger’ species, using both forelimbs and incisors to dig tunnels in extremely hard soils. C. talarum showed relatively larger forelimb extensors than C. australis. Moreover, I hypothesize that the structure of the ulna in C. talarum may increase the effective forces of the digital and carpal flexors, thus accounting for the enhanced digging ability in this species. Outward forces exerted by the distal elements (claws-digits-carpals) when forelimbs impact the soil appear to be a critical factor in loosening soil fragments. In addition, the increased upper incisor procumbency of C. talarum correlated with an effective chisel-tooth digging behaviour. Finally, I briefly examine phylogenetic and biogeographical factors that may account for some C. australis morphological and physiological traits. It is suggested that the digging ability of C. australis could be a by-product of its larger size, a likely adaptation to evade predation.

The diet of the brown skua (Catharacta skua lönnbergi) was studied at Mayes Island, Kerguelen archipelago, by collection of prey remains on 11 territories during the complete breeding cycle of the species there. In nine territories, collections were daily or every two days for a quantitative investigation of the diet. The blue petrel (Halobaena caerulea) and thin-billed prion (Pachyptila belcheri) accounted for, respectively, 72.9 and 19% of the remains. Differences in diet and prey capture rate were analysed according to territory size, local abundance of prey inferred from the vegetation cover of territories, colony attendance patterns of prey, and according to the breeding timing and success of skuas. Skuas holding large territories caught more prey, and especially more blue petrels than those with small territories. Diet reflected local abundance of blue petrel and thin-billed prion but the blue petrel was apparently preferred to other available prey. Failure to breed was not significantly related to hunting performance of the skua or to food availability, but sample size was small. Variations over time of prey capture rates reflected the colony attendance patterns of the main prey. Captures of blue petrel and thin-billed prion were most numerous during their respective laying, incubation and hatching periods, decreasing during chick-rearing. Prey capture rates were greatest when brown skuas were hatching, and decreased during chick-rearing to a minimum when young skuas were fledged. Capture rate patterns differed according to laying date of skuas: early breeding skuas caught more prey and were well synchronized with the breeding cycle of the blue petrel and late breeders exhibited more dependence on the thin-billed prion for some periods. Finally, this study has allowed us to assess the impact of the brown skuas upon the burrowing petrels on this locality.

Pipistrellus pipistrellus, Eptesicus serotinus, Nyctalus noctula, N. leisleri, Myotis daubentonii, M. myotis, unidentified small Myotis spp. and Plecotus spp. were recorded during bat detector transects within a central European city of 350,000 inhabitants. Bats were recorded in all seven habitat types under study, the levels of activity for each species and habitat type were significantly different. The relative activity of the whole bat community was highest in old outskirts (low density housing) and at the river, and lowest in the city centre and new housing estates (high density housing). Significant differences were found in the timing of bat activity during the night and the season. Within the first two hours after sunset, relative activity of P. pipistrellus and E. serotinus was highest in the first 0.5 h and decreased thereafter. In N. noctula, it was highest during the second and third 0.5 h and in Myotis spp. it was low in the first 0.5 h and increased till the end of monitoring. Flying bats were recorded from March till October; the lunar cycle had no significant effect on the amount of flight activity. The relative activity of E. serotinus was positively correlated with temperature. No significant correlation was found between the activity of bats and the number of trees and streetlamps per transect. Comparison with the results of an earlier visual census showed that more bats were recorded acoustically than visually except in the city centre. This is attributed to the effect of white streetlamps during the visual census. During the acoustic census, most white lamps were replaced by yellow lamps which biased the impact of lamps on bat traffic. Nevertheless, bat species known to benefit from white streetlamps remained the most common foragers within the city.

The vertebral column of Scutisorex somereni (the hero shrew), and its size and morphology, is probably the most modified among the vertebrates (Kingdon, 1974). We examined the scaling of diameter versus length in the long bones and ribs, and spine mass versus body mass of this species, in comparison to 19 other mammalian taxa (including fossorial species). The ribs of Scutisorex are significantly more robust than any genus examined, and the spine of this species, relative to its body mass, is four times more robust than that reported for any other vertebrate. Paradoxically, the long bones of the limbs of Scutisorex demonstrate no difference in robustness from that predicted for an animal of its body mass. There is no satisfactory ecological, behavioural, or functional explanation for this unique spinal morphology.

The spine of Scutisorex somereni, the hero shrew, is probably the most highly modified among the vertebrates (Kingdon, 1974), yet no description of the accompanying spinal musculature has been published. This paper describes the anatomy and proposed functions of the major epaxial and hypaxial muscle groups of Scutisorex. The unusual vertebral morphology of this species is accompanied by major modifications in some of the spinal muscle groups. The transverse spinalis muscles are the most modified, and this is probably related to the presence of bony interdigitating tubercles on the vertebrae. The longissimus muscles possess long tendons that share attachment with the iliocostalis muscles. The iliopsoas muscles and their sites of attachment are greatly enlarged in comparison to those of Blarina and Rattus. Much of the spinal musculature reflects the highly modified state of the Scutisorex vertebrae. The unique behavioural function of the Scutisorex spinal modification, if any exists, is not known

The phylogenetic relationships of eight genera within the Calappidae H. Milne Edwards, 1837 (Crustacea: Brachyura) were examined based on a cladistic analysis of 55 adult morphological characters. A single tree was produced (CI=0.833, RCI=0.717). The data revealed two major lineages within the Calappidae: the ‘calappine’ clade, consisting of Calappa, Cryptosoma, Cycloes, Paracyclois and Cyclozodion, and the ‘mursiine’ clade, consisting of Acanthocarpus, Mursia and Platymera. Analyses of the fossil record and biogeographic patterns point to vicariance events associated with Gondwanan fragmentation. Optimization of depth distributions on the cladogram suggests that the family had a deep-water origin with only a single lineage moving into shallow waters.