Some aspects of the colony and social structure of the Ghana mole-rat Cryptomys zechi were studied in a mesic Guinea savanna woodland in Ghana. Colony size ranged between one and seven (average 3.6). The mean adult body weight was 217.9 g and the colony biomass was 634 g. Responsibility for colony safety in C. zechi, as revealed from order of capture in response to damage to the burrow system, is age dependent, with sub-adults being the most frequent repairers. There are indications that male workers are more involved in colony maintenance than females and that the reproductive individuals, especially the males, perform little work. We discuss the finding that C. zechi although a social bathyergid, is close to the bottom of the sociality ladder.

The tentacled snake Erpeton tentaculatum lives its entire life in fresh water where it feeds mostly on fish. Because the tentacled snake strikes underwater, the physical demands differ from those of air, and require modified methods of prey capture compared to terrestrial snakes. To examine this, we scored the feeding behaviours of five snakes and used multiple high-speed films of two snakes striking fishes. In the pre-strike phase, the snake usually assumed a J-shaped posture with its head turned posteriorly at the neck and its body held straight. The snake waited in such a rigid posture for the fish to move into the very narrow ‘window’ between turned head and body. Tentacles remained erected, and motionless. The strike was extremely rapid, occurring typically from pre-set J-shaped postures, not from sigmoidal body coils. As the head turned and travelled to the fish, the mouth opened and water collected in the ballooning throat. Significant suction feeding was absent. The fish was secured on buccal teeth and quickly swallowed by unilateral displacements of the jaws. Prey capture and swallowing exhibited specialized modifications of the general snake predatory behaviour to address the hydrodynamic demands of such an underwater strike.

Current life-history paradigms predict that an organism's total reproductive output is determined by its intrinsic level of ‘reproductive effort’ (RE), interacting with local resource availability. In turn, RE is driven by ‘costs of reproduction’. Within the total allocation, selective forces on offspring size ultimately determine both the number and size of offspring (because of a trade-off between these two traits). Although patterns of life-history variation are broadly consistent with this scenario, the evidence is weak: it is generally difficult to measure ‘costs’ or selective forces on offspring size. To test this paradigm, we need a study organism which differs in these respects from related taxa, so that we can unequivocally generate predictions about life-history traits. A remarkable island population of Asian pit-vipers Gloydius shedaoensis was studied for which (unlike mainland conspecifics) ‘costs of reproduction’ are low, food availability is high, and there is intense selection for large offspring size. Maternal body sizes and condition, and offspring numbers and sizes were quantified for 79 litters over 2 years. As predicted, the snakes display high reproductive output per female (relative to maternal body mass, litter mass is about twice as high as in related taxa), large offspring size (about three times the mass of related taxa) and a strong trade-off between offspring size and litter size. Reproductive output was only weakly correlated with maternal body size, and output was adjusted mostly by manipulating litter size rather than offspring size. Reproductive output varied between years, but maternal body condition after parturition did not. Measures of reproductive output (such as the mass or energy content of the litter) bear little relationship to ‘costs of reproduction’ in this system.

Over 15 years (1983–97) 25 665 random encounter captures of adult sleepy lizards, Tiliqua rugosa, were made at a site near Mt Mary, in the mid-north of South Australia. The last months of winter (July and August) became warmer and drier in the later years of the study, and the spring months when lizard activity was highest (September and October) had increased rainfall. The lizards form monogamous pairs for an average of 8 weeks before mating in late October or early November. Pairing started earlier and lasted longer in later years of the study. The time when pairing ended showed no significant temporal trend, although it was earlier in years with warmer spring temperatures. These results suggest that the timing of reproductive behaviour was influenced by climatic variation.

The opportunity for selection, I, calculated as the variance in relative fitness, sets an upper limit to the amount of adaptive change that selection may produce. Therefore, it is a potentially valuable, and frequently used, measure of the potential of action of phenotypic selection. Although many different aspects of I calculation and analysis have been explored, the effect of the spatial scale chosen for calculation received little attention, notwithstanding the growing evidence that natural populations are not homogeneous and present a hierarchical spatial structure. The effect of scale on the estimation of I was examined from data collected in two populations of southern elephant seals (Mirounga leonina), an easily observable and strongly polygynous species. A significant effect of spatial scale on three important aspects of I calculation and analysis was found: dependence of I on mean fitness, between population variation of I, and effect of local demography on I.

Dispersal patterns were investigated in the common wombat Vombatus ursinus using microsatellite genetic data collected from three study sites. Two of these were within large, high-density populations in Victoria, south-eastern Australia, while the third was a small, isolated population in South Australia. Genetic assignment tests revealed that in the continuous populations, females were more likely to be immigrants into the sampling areas than were males, who were more likely to have been born locally. No such difference between the sexes was detected for the isolated population. At all three sites, pairwise relatedness estimates for males were negatively correlated with geographic distance, suggesting related males were clustered. This pattern was not observed among females, other than in the isolated population, where pairs of females showed a weak decline of relatedness with increasing geographic distance over a large spatial scale. Taken together, these data provide strong evidence that dispersal is predominantly by females. Furthermore, the observed spatial structure of relatedness suggests female breeding dispersal, a rare finding among mammalian species. Genetic variation within the isolated population was significantly reduced compared to the sites in Victoria. Our data are not sufficient to distinguish between two possible causes for this: (1) long-term small size and isolation of populations at the edge of the species' range where resources may be more patchily distributed; (2) a genetic bottleneck effect of recent isolation resulting from agricultural development.

Morphological variation was studied in the crania of seven species of kangaroos and wallabies (Macropus). How function and phylogeny interact to influence cranial form amongst adults of diverse species was considered. Thirty-six, three-dimensional landmarks were acquired on each of 65 adult Macropus specimens from Western Australia. The different species occupy a wide range of habitats and latitudes and there are well-known differences in diet among the species. Size and shape variability was examined using the methods of geometric morphometrics. Aspects of inter-specific variation explained by principal components were visualized and examined for correlations with size, latitude, and diet. The first principal component correlates strongly with inter-specific differences in latitude and it primarily contrasts species on the basis of the relative length of the snout anterior to the molar teeth, this being greater in species that live in cooler climates. Species scores on the second principal component correlate strongly with centroid size such that smaller crania have more flexed muzzles. Principal component three separates the short grass-eating, red kangaroo M. rufus, from all other species (most of which eat tough herbage from trees and shrubs). This principal component represents differences in the masticatory apparatus. Variation on the fourth principal component also seems to be functionally interpretable in terms of further differences in the masticatory apparatus of M. agilis. The relationship between phylogeny and cranial form was investigated by comparing a phenogram based on the shape distances between taxa with a consensus phylogeny drawn from the literature on Macropus genetics, ecology and morphology. The phenogram shows considerable similarity to current taxonomic views, but, our results also indicate differences that are related to function. Thus, this study serves to unravel the interaction of functional and phylogenetic influences on cranial form amongst Macropus species and raises further issues relating to ontogeny and phylogeny.

Dental polymorphism in a population of the red fox Vulpes vulpes (L.) from Poland was studied in a sample of 1453 specimens (637 males, 535 females and 281 specimens of unknown sex). Frequency distributions in 15 groups of morphotypes (A–O) were analysed and a pattern of qualitative features was constructed on the ground of frequency analysis of particular morphotypes. An increase in complication of tooth shape of the carnassial region (P4, P4, M1, M1), as well as higher morphological variation of the teeth from borders of the cheek rows (P1, P1, M2, M3) were ascertained. Almost all groups of morphotypes, excluding three, presented absence of significant sexual differences. The pattern of qualitative features was used to verify an existing model of genetic control of evolutionary changes in dental morphology of mammals. Positive, statistically significant relationships between the dental size and presence or degree of formation of the dental structures confirmed the operation of the size-related mechanism, i.e. threshold mechanism, during ontogeny.

The Channel Island of Jersey is 116 km2 but has only 540 ha of woodland distributed in 237 wooded fragments with mean size of 2.5 ha. Despite this, the island supports 300 to 600 red squirrels Sciurus vulgaris, a species that is under threat in mainland Britain from habitat fragmentation, disease and the spread of the alien grey squirrel S. carolinensis. Grey squirrels are not present on Jersey. Between 1994 and 1997, using trapping and tracking techniques, we studied how red squirrels survive on Jersey by focusing on three local populations in sites B, C and S with contrasting food availability. The primary squirrel foods at site B were autumn tree seeds, at site C autumn tree seeds and summer conifer cones, and at site S autumn tree seeds and ad libitum, year-round supplementary food provided by local people. The densities of squirrels in site C (mean over 3 years 0.97 ha−1) and site S (1.21 ha−1) were more than one and a half times that of site B (0.68 ha−1), which relied on autumn seeds. Body mass and condition, and early breeding (spring litters) were not affected by food availability although conception occurred as early as November, earlier than in mainland Britain. Less than 50% of females produced summer litters, and 88% of non-breeders did not receive supplementary food. Turnover rates were lowest and most stable in site B. Annual residency was not influenced by the size of the natural tree seed crop. Cat and road kills caused two out of three reported deaths. This island population seems to remain viable as a result of an extended breeding season and increased population densities in sites with summer or supplementary food. The results emphasize the beneficial effects of extra food provided by local people. This provides a buffering effect against variations in natural food availability, and seems to be important for their long-term survival.

Aspects of the ecology of populations of the western pond turtle Clemmys marmorata were investigated in the Mojave River of the central Mojave Desert, California, U.S.A. One population occupied man-made ponds and the other occurred in natural ponds in the flood plain of the Mojave River. Both habitats are severely degraded as a result of ground water depletion from human activities along the river and one is infested with the exotic shrub saltcedar Tamarix ramosissima. Mean female carapace length (CL) was significantly greater (14.4 cm) than that of males (13.7 cm). Live juveniles were not detected during the period of study. Shelled eggs were visible in X-radiographs from 26 May to 14 July. Mean clutch size was 4.46 and ranged from 3 to 6 eggs. Clutch size did not vary between 1998 and 1999 but was significantly correlated with CL for both years combined, increasing at the rate of 0.548 eggs/cm CL. Gravid female CL ranged from 13.3–16.0 cm. Some females nested in both years. Mean X-ray egg width (21.8 mm) was not significantly correlated with CL or clutch size. X-ray egg width differed more among clutches than within, whether including CL as a co-variate or not. Nesting migrations occurred from 6 June to 8 July with minimum round trip distances ranging from 17.5–585 m with a mean of 195 m. Mean estimated time of departure as measured at the drift fence was 18:13. Most females returned to the ponds in the early morning. Nesting migrations required females to be out of the water for estimated periods of 0.83 to 86 h. The destination of nesting females was typically fluvial sand bars in the channel of the dry riverbed. Overall, the ecology of C. marmorata in the Mojave River is very similar to that reported for populations in less severe habitats along the west coast of the United States. Notable exceptions include long nesting migrations to sandbars in the dry river channel, a possible result of human modifications to the environment, and an apparent lack of terrestrial overwintering behaviour in Mojave River populations. The general similarity of desert and coastal populations is possibly a reflection of their recent geographic separation. Overall, populations in the Mojave River exhibit few obvious adaptations to living in the desert and are considered to be tenuous relicts of the Pleistocene. The small size and tenuous status of these populations suggests that immediate conservation action is needed, including establishment of satellite populations as a hedge against extirpation.

Johnstone Strait provides important summer habitat for the northern resident killer whales Orcinus orca of British Columbia. The site is also an active whale-watching area. A voluntary code of conduct requests that boats do not approach whales closer than 100 m to address perceived, rather than demonstrated, effects of boat traffic on killer whales. The purpose of the study was to test the relevance of this distance guideline. Relationships between boat traffic and whale behaviour were studied in 1995 and 1996 by shore-based theodolite tracking of 25 identifiable focal animals from the population of 209 whales. Individual killer whales were repeatedly tracked in the absence of boats and during approaches by a 5.2 m motorboat that paralleled each whale at 100 m. In addition, whales were tracked opportunistically, when no effort was made to manipulate boat traffic. Dive times, swim speeds, and surface-active behaviours such as breaching and spy-hopping were recorded. On average, male killer whales swam significantly faster than females. Whales responded to experimental approaches by adopting a less predictable path than observed during the preceding, no-boat period, although males and females used subtly different avoidance tactics. Females responded by swimming faster and increasing the angle between successive dives, whereas males maintained their speed and chose a smooth, but less direct, path. Canonical correlations between whale behaviour and vessel proximity are consistent with these conclusions, which suggest that weakening whale-watching guidelines, or not enforcing them, would result in higher levels of disturbance. High variability in whale behaviour underscores the importance of large sample size and extensive experimentation when assessing the impacts of human activity on killer whales.

Interspecific comparisons of mammals and primates suggest that the major determinants of gregarious behaviour are the distribution of food resources in space and time, predation pressure and infanticide avoidance. This study of gregarious behaviour in the spectral tarsier Tarsius spectrum at Tangkoko Nature Reserve, Sulawesi Indonesia suggests that all three may be important in understanding the relatively gregarious nature of spectral tarsiers. To test whether predation pressure was the major determinant of sociality for this species, I mimicked predation pressure by using predator models and playback predator vocalizations. In response to increased predation pressure from rubber models of snakes, the family group was observed mobbing the ‘predator’. On the other hand, when plastic bird of prey models were placed throughout the tarsier's territory the adult group members often increased their distance from one another. No significant response was made by the spectral tarsiers in response to playbacks of predator vocalizations. To test whether infanticide avoidance was the major determinant of sociality for this species, I compared the distance between adult males and females for three reproductive phases. When adult females were lactating, adult males were observed to decrease the distance between themselves and the adult female, while the female often attempted to increase the distance. However, groups containing either a pregnant female or a non-reproductive (cycling) female did not differ in their gregariousness. To explore whether the temporal distribution of resources was the major determinant of sociality in spectral tarsiers I collected insects hourly. The diet of spectral tarsiers is restricted to insects. Distance between group members closely followed hourly and monthly changes in insect abundance. During hours when abundance was high, distance between group members decreased and vice versa. Additional long-term and more fine-grained data need to be collected to ascertain the relative importance of resources, predators and infanticide in determining sociality in the spectral tarsier.

Female Cape ground squirrels Xerus inauris live in matrilineal kin groups in which the number of reproductive positions is limited to three females. Field observations on a population in Namibia revealed that the mechanisms by which group size was limited were reproductive suppression and group fission. Sub-adult females attained sexual maturity at 8 months of age when only a single adult female was present in their social group, whereas sub-adult females in groups with more than one adult female matured at 12 months of age. Social groups with more than three breeding females subsequently split into smaller groups. Several hypotheses for limiting group size were considered. There was no evidence of higher ectoparasite loads on females in larger groups, nor was survival of adult females affected by group size. Although adult females have lower body masses and higher mortality during the winter when food is more scarce, feeding competition alone does not seem to limit group size. Groups that split continued to overlap in their feeding ranges and there was no seasonal difference in juvenile survival. However, juvenile survival was affected by group size. The greatest cost of being in a larger group was lower juvenile survival. Larger groups use larger feeding ranges, and because squirrels return to their sleeping burrow when threatened, not just to the nearest refuge, slower juveniles have greater exposure to predators. Thus, although competition for food resources may be important, predation seems to be a major constraint on female group size as well as the primary selective force leading to female group formation.

Winter attendance patterns of lactating Steller sea lions Eumetopias jubatus and their offspring were recorded during the late stages of nursing when the young were expected to move from milk to independent foraging. Trip duration and nursing visits to shore by 24 mothers with pups (7–9 months old) and six mothers with yearlings (19–21 months old) were noted during 600 h of observations (from 22 January to 1 April 1996) at a non-breeding haulout site in south-eastern Alaska. Pups and yearlings tended to stay on or near the haulout while their mothers were away and showed no signs of weaning during winter. Their average trips to sea were 43% shorter in duration than those of lactating females, suggesting that pups and yearlings make independent trips away from the haulout while their mothers forage. The winter attendance cycle of lactating females (consisting of one trip to sea and one visit on land) averaged about 3 days, with the mothers of pups spending an average of 15 h of this time onshore with their offspring. The winter attendance cycle of pups and yearlings averaged just over 2 days, with the immature sea lions spending an average of 22 h on shore. Foraging trips by mothers of yearlings were significantly longer than those by mothers of pups. However, there was no significant difference in the foraging times of mothers of male and female pups. Lactating females spent more time at sea during winter than during summer. The probability of sighting an individual on the winter haulout during daylight hours was 15% for lactating females and 40% for immature animals.

The timing and duration of activity and foraging behaviour of mahogany gliders Petaurus gracilis was studied every 2 months over 2 years by direct observation. The amount of time spent active each night throughout the year ranged from 8 to 10.1 h (or 63–80% of the dark phase) and did not change significantly between the wet and dry seasons. Although gliders generally had one continuous period of activity, they were observed on eight occasions to return to their dens during the night for a mean of 85 min, with a mean entrance and exit being 22:59 and 00:25, respectively. The amount of time spent foraging (i.e. feeding and travelling) ranged from 40% of the time outside the den in January to 77% in September. The overall mean was 61.1%, with the remainder of the night spent either stationary (mean 24.3%), grooming (mean 11.8%), in the den and then re-emerging (mean 2.5%) or vocalizing (mean 0.3%). Activity comprised mostly the behaviours associated with foraging: feeding (44.9%), climbing (13.2%) and gliding (3.0%). The amount of time spent active and feeding was similar to that observed for other petaurid marsupials such as yellow-bellied glider P. australis, sugar glider P. breviceps and squirrel glider P. norfolcensis. There is a general relationship between diet, body size and amount of time spent feeding among the exudivorous gliders and folivorous possums, with feeding time increasing with increasing body mass in exudivorous possums and decreasing with increasing body mass in folivorous possums.

Food habits of tigers Panthera tigris and population attributes of prey species (population structure, density and biomass) were studied in the tropical dry deciduous forest of Pench National Park, Central India, from November 1998 to April 1999. Scat analysis and line transect method were used to estimate tiger food habits and density of major prey species, respectively. The 61.1 km2 intensive study area was found to have very high ungulate density (90.3 animals km−2) with chital Axis axis being the most common species (80.7 animals km−2), followed by sambar Cervus unicolor (6.1 animals km−2). Common langur Presbytis entellus was the most abundant (77.2 animals km−2) primate species. When the density figures were multiplied by the average weight of each prey species, a high biomass density of 6013.25 kg km−2 was obtained for the intensive study area. Chital (47.3%) along with sambar (14.5%) and wild pig Sus scrofa (10.9%) constituted the major part of the tiger's diet. If there is food choice, tigers seem to kill medium- and large-sized species more often. Wild pig and sambar were consumed more than their availability, whereas chital were taken in proportion to their availability. Gaur Bos gaurus and nilgai Bosephalus tragocamelus were not represented in the tiger's diet. Common langur was consumed in lesser proportion by tigers than expected by estimates of its density. The average weight of animals consumed by tigers in the intensive study area was 82.1 kg. The analyses revealed that Pench harbours very high prey density and tigers are mostly dependent on the wild ungulates rather than on domestic livestock as is the case in many other areas in the Indian subcontinent. These two factors thus make Pench National Park a potential area for long-term conservation of tigers.

The following Applications were published on 28 September 2001 in Volume 58, Part 3 of the Bulletin of Zoological Nomenclature. Comment or advice on any of these Applications is invited for publication (subject to editing) in the Bulletin and should be sent to the Executive Secretary, International Commission on Zoological Nomenclature, c/o The Natural History Museum, Cromwell Road, London SW7 5BD, U.K. (e-mail: iczn@nhm.ac.uk).

Between 1987 and 1996 the numbers of badgers Meles meles in Wytham Woods rose from 60 to 228 adults. The area occupied by the population has not changed and thus density has also risen from 10 adult badgers/km2 to 38/km2. This rise parallels an increase in badger abundance seen across Britain in recent years. The hypothesis that this increase is either the consequence of improved badger protection or of changes in habitat can be rejected for this site. Instead, a link between increasing numbers and changing weather patterns, possibly resulting from climate change, is investigated. In particular, attention is drawn to a correlation between mild winters and heavier body weights of badgers in January. Furthermore socio-spatial restructuring within the population may be the mechanism that has permitted high density to be sustainable. The increase in badger numbers at Wytham has not affected population sex ratio, which has remained relatively constant at parity throughout the study.

INTERNATIONAL COMMISSION ON ZOOLOGICAL NOMENCLATURE

The following Applications were published on 29 June 2001 in Volume 58, Part 2 of the Bulletin of Zoological Nomenclature. Comment or advice on any of these Applications is invited for publication (subject to editing) in the Bulletin and should be sent to the Executive Secretary, International Commission on Zoological Nomenclature, c/o The Natural History Museum, Cromwell Road, London SW7 5BD, U.K. (e-mail: iczn@nhm.ac.uk).