The tiny honey possum, Tarsipes rostratus, is the only marsupial that feeds solely upon nectar and pollen. Its daily energy expenditure is reduced by occasional short-term deep torpor but its overall nitrogen needs appear to be what would be predicted for its size (7–12 g). Tarsipes derives its nutrients from digesting the contents of pollen grains. Simultaneously, it must eliminate the large volumes of water that accompany the energy-rich sugars in nectar. We suggest that these two time-consuming processes, together with the need to harvest small amounts of nectar and pollen from a large number of flowers, limit the rate at which Tarsipes can raise young. Tarsipes has a small litter (2–4 young) compared with marsupials of similar size and its young grow only slowly, both traits that may stem from dietary constraints. However, it breeds first only 4 months after leaving the pouch and continuously thereafter, which may offset an annual adult mortality rate of 86%. Unusually in a small marsupial, the young are carried in a pouch until almost weaned, rather than deposited in a nest. This too may be a correlate of the way it harvests nutritionally rewarding plant products. Nectar and pollen are available all year from the flowers of a suite of banksias and dryandras that are Tarsipes' favoured foodplants. Only the species-rich Mediterranean-climate heathlands of south-western Australia appear able to support a small marsupial with such extremely specialized dietary habits, whose life-history traits reflect the constraints of this unusual diet.

Redbelly snakes Storeria occipitomaculata have a characteristic agonistic display involving conspicuous lip-curling and head distortion. The lip-curling and head distortion display is similar to head shape-changes during feeding. Storeria occipitomaculata produced mouth secretions while displaying. Micrographs of maxillae and observation of changes in head configuration showed that the lip-curling behaviour of S. occipitomaculata is related to the presence of carina-bearing maxillary teeth, which are protruded from the mouth during the display. I compared the behaviour and morphology of this species to other gastropod-eating snakes and suggest that these behavioural and morphological characteristics have a two-fold role: in prey capture they aid the capture, the handling, and perhaps the digestion of prey; in predator deterrence they may act as delivery agents for mouth secretions.

The composition of egg yolks and neonates of the viviparous lizard, Pseudemoia pagenstecheri, one of the most placentotrophic reptiles studied to date, are described. Neonates (43.3 ± 5.2 mg) have twice the dry mass of the initial eggs (22.0 ± 1.9 mg). The protein content of neonates (29.1 ± 1.1 mg) is more than twice that of eggs (12.2 ± 1.1 mg), while the energy content (908.1 ± 107.4 J) is 1.6 times higher than that of the egg (565.0 ± 42.9 J). The energy densities of eggs (27.5 kJ g−1) and neonates (23.1 ± 0.3 kJ g−1) are similar to the energy densities of eggs and neonates of oviparous species. The total ash per neonate (4.1 ± 0.4 mg) is three times greater than that of the egg contents (1.4 ± 0.2). Neonates contain significantly more calcium, sodium and potassium, but not magnesium, than do eggs. Thus, the placenta has a quantitatively important role in supplying nutrients for the embryo. The proportions of triacylglycerol (66%), phospholipid (19%), and free cholesterol (5%) in the eggs are similar to those in eggs of birds and crocodilians, but the proportion of cholesteryl esters (7%) is much higher in eggs of P. pagenstecheri. The proportion of docosahexaenoic acid in the egg phospholipid is relatively low (1.4%) but rises to 5.4% in the neonate. The eggs contain vitamin E (mainly in the form of α-tocopherol) and vitamin A, but no detectable carotenoids. The overall composition of the eggs is not substantially different from that of oviparous species, suggesting that the small egg size relative to neonate size is a result of a reduction in egg size rather than modification by omission of some nutrients from the yolk. The pattern of placental nutrient provision of P. pagenstecheri contains both an obligate and a facultative component suggesting that enhancement of offspring quality through facultative placentotrophy is a general characteristic of placental reptiles independent of pattern of embryonic nutrient provision.

Survival of juvenile Weddell seals Leptonychotes weddellii in McMurdo Sound, Antarctica was examined using 25 years of tagging and resighting data. Using mark–recapture models, we estimated age- and sex-specific apparent survival (survival confounded with emigration) rates of Weddell seals from birth to 6 years of age for 17 cohorts (1973–89). Survival in the first 2 years of life (0.429 and 0.635 for the first and second years, respectively) was lower than annual survival after 2 years of age (0.806), and was significantly lower for males than for females. First-year survival of the 1978 and 1983 cohorts was significantly lower than average first-year survival across cohorts. Reproductive rate of adult females was significantly correlated with first-year survival in concurrent years, but not when first-year survival lagged reproductive rate by 1 year nor with annual survival after 1 year of age. This correlation, however, was only significant in male first-year survival, possibly indicating that survival of males is more dependent on maternal or environmental conditions than survival of females. Average weaning mass varied significantly among cohorts and was nearly correlated to reproductive rate of adult females. This may indicate that maternal condition is reduced in years of low reproduction although more data are needed to test this conclusively.

This study investigated the reproductive biology of a captive population of brush-tailed phascogales Phascogale tapoatafa. A ‘round robin’ mating system was established in which seven adult male animals were rotated through seven adult females. Changes in vaginal cytology and peripheral plasma progesterone and oestradiol levels were monitored to determine features of the female reproductive cycle. Regular measurement of scrotal diameter, collection of testicular biopsies and monitoring of plasma testosterone levels was used to assess male reproductive activity. Oestrous cycle length was estimated as 40 ± 5 days (n = 7) and gestation length as 27 ± 5 days (n = 7). Plasma progesterone levels showed no significant variation. This negative result is attributed to the small sample size (n = 4). Plasma oestradiol levels however, followed the predicted pattern, with an increase in peripheral concentration occurring prior to the breeding season. Oestradiol concentration peaked at 246.9 ± 169.2 pg ml−1 (mean ± SE) just before mating and declined to 24.3 ± 12.0 pg ml−1 after mating. Histological studies of testicular biopsies revealed that spermatogenesis does not cease until after the breeding season has begun, in contrast to Antechinus species, in which spermatogenesis ceases before breeding. Plasma testosterone levels increased at the onset of the breeding season, peaking at 6.3 ± 0.60 ng ml−1. Testosterone concentrations remained high until approximately 3 weeks after breeding, followed by a decline to pre-breeding levels. Litter size and sex ratio did not vary significantly between first- and second-year females. Females did not undergo a second oestrous cycle when pouch young were removed 15 and 17 days after parturition.

Wing feather mite burdens on seven species of passerine birds (Carduelis carduelis – goldfinch; C. chloris – greenfinch; Serinus serinus – serin; Sylvia atricapilla – blackcap; Sylvia melanocephala – Sardinian warbler; Turdus merula – blackbird; Passer domesticus – house sparrow) from Portugal were assessed by the subjective semi-quantitative scoring system of Behnke et al. (1995) in order to evaluate more fully the accuracy and reliability of the technique. Our analysis indicated that in all species, scores allocated to flight feathers showed a significant positive relationship with mite counts as assessed through microscopical examination of the same feathers. However, there were differences between species of birds. Of the species examined, goldfinches and greenfinches showed the weakest relationships between assigned mite scores and actual mite numbers indicating that the technique was less accurate when applied to these species compared with the remaining five. No evidence was found that anything more was to be gained from scoring both wings, rather than just one. Feather mites (Proctophyllodes spp., Trouessartia incisa) were also detected on tail feathers, but the assessment of these feathers presented additional problems and it was concluded that in the interests of minimizing handling time of birds, tail scores had little more to offer. We conclude that scoring all the flight feathers (including all primary, secondary, and tertiary feathers) on one entire wing, but alternating between left and right wings of birds within a species, represents an acceptable compromise between sufficiently detailed examination and minimization of bird handling time in the field.

The feeding habits and foraging modes of six species of shrew (Insectivora, Soricidae) coexisting in the forests of the Russian Far East were investigated in order to quantify levels of niche overlap and elucidate the role of body size in ecological separation. Overlap in numbers of shared prey taxa was high and Lithobiomorpha, one of the most abundant macro-invertebrates in field samples, was a major prey item of all species. The composition of different prey taxa in the diet of Sorex unguiculatus and the abundance of these taxa in field samples were positively correlated. Major differences in dietary composition and foraging mode reflected body size of shrews. While the niches of individual species were not exclusive, small species fed only on arthropods, were epigeal, and had relatively narrow niche breadths. Large species fed extensively on lumbricids and other soil-dwelling invertebrates, and were hypogeal. There were significant negative correlations between niche overlap in terms of prey composition, prey size and prey location, and increasing body-length ratios in pair-wise comparisons. Combined niche overlap was reduced with increasing divergence of body size. Adjacent species-pairs in the size series had a mean combined niche overlap of 88% compared with non-adjacent pairs of 67%. The most significant areas of ecological separation between species as a function of body size were in the dietary occurrence of small versus large prey and in the foraging mode (epigeal versus hypogeal). These findings confirm that body size has an important role in effecting ecological separation in multi-species communities where a high degree of morphological and ecological similarity occurs between members.

On morphological and chromosomal grounds Pipistrellus (Arielulus) subgenus is elevated to generic rank and the recently described genus Thainycteris has been synonymized with Arielulus. Besides this taxonomic revision, a new species of bat Arielulus torquatus is described from the central mountains of Taiwan which differs from its congeners chiefly by its size and colouration.

Natural nest-site selection was investigated in 50 radiocollared southern flying squirrels Glaucomys volans during spring and summer, 1994–1996, in the Ouachita National Forest of Arkansas. Squirrels nested in 226 trees in a variety of habitats at five study areas. Contrary to previous reports describing southern flying squirrels as habitat generalists, in this study squirrels showed selection in both the habitat and tree type in which nests were placed. Where it was available, mature pine–hardwood forest was selected for nesting. Young (< 15 years old) and immature (15–40 years old) pine plantations and harvested areas were avoided as nesting habitats. At harvested study areas, squirrels nested in protected riparian mature forest strips (greenbelt) along, and 10–20 m either side of, intermittent creeks and in adjacent mature forests. Squirrels constructed only outside nests in pine trees. In mature pine–hardwood forest, pines were used for outside nests more frequently than hardwoods; in greenbelt habitat, pines and hardwoods were chosen equally for outside nests. Both outside and cavity nests were found in hardwoods; standing dead trees (snags) contained only cavity nests. Snags were selected over hardwoods for cavity nesting in both mature pine–hardwood forest and greenbelt habitat. All hardwood species and all decay classes of snags were used for diurnal nesting in greater frequency than expected. Considering both cavity and outside nest-site selection, pines were used less than expected. Results suggest that mature forests are optimal flying squirrel nesting habitats and should be retained adjacent to harvested areas to provide resources to squirrels abandoning stands after disturbance. Within harvested areas, nesting habitat can be substantially improved through the retention of overstory hardwoods and snags, as well as protection of mature forest strips along drainages.

Seventeen populations of T. hermanni in Greece differed substantially in mean adult body size, over a range of about one and a half times in length and three times in mass. Females were the larger sex in all populations; the degree of sexual size dimorphism did not vary with mean body size. The proximate cause of the variation of body size among populations was differences in the duration of growth, rather than egg or hatchling size or the growth rates of juveniles. The age at maturity (α) increased with body size in the 17 populations, while the Bertalanffy growth constant (k) decreased with body size. The quantities αM and M/k (where M is the instantaneous mortality rate) were invariant with body size, suggesting that differences between populations were adaptive rather than the result of short-term disturbance. Body size was greater in cooler areas, and increased with both latitude and altitude. This pattern is opposite to that found in most ectotherms (the reverse Bergmann's rule), and to that which occurs between tortoise species. Several hypotheses about the possible ultimate causes of variation of body size were rejected, including adaptation to long-term habitat disturbance (land use), character displacement, social factors, energetics, thermoregulation, r-K selection, the length of the season available for incubation, or differences in juvenile mortality. The most likely ultimate cause of size variation between sites is differences in adult mortality, the correlation with environmental temperature being through the frequency of fires.

Analyses of mitochondrial (mt) DNA control region sequences from 175 leatherback turtles Dermochelys coriacea from 10 nesting colonies revealed shallow phylogenetic structuring of maternal lineages on a global scale. Eleven haplotypes were observed, and mean estimated sequence divergence, p = 0.00581, is much lower than the deepest nodes reported in global mtDNA surveys of the green turtle Chelonia mydas, loggerhead Caretta caretta, and ridley turtles Lepidochelys spp. The leatherback turtle is the product of an evolutionary trajectory originating at least 100 million years ago, yet the intraspecific phylogeny recorded in mitochondrial lineages may trace back less than 900 000 years. The gene genealogy and global distribution of mtDNA haplotypes indicate that leatherbacks may have radiated from a narrow refugium, possibly in the Indian–Pacific during the early Pleistocene glaciation. Analysis of haplotype frequencies revealed that nesting populations are strongly subdivided globally (FST = 0.415), and within ocean basins (FST = 0.203–0.253), despite the leatherback's highly migratory nature. Within the Atlantic significant differences in haplotype frequency distributions and Nm values < 2 are observed in pairwise comparisons between St. Croix (U.S. Virgin Islands) and mainland Caribbean populations, and between Trinidad and the same mainland populations. These findings provisionally support the natal homing hypothesis for leatherback turtles, although several proximal nesting populations were indistinguishable, suggesting recent colonization or less precise natal homing behaviour than documented for other marine turtle species. The evidence of natal homing, manifested on ecological time scales, may be erased in some populations by rapid rookery turnover resulting from climatic fluctuation and the ephemeral nature of nesting habitat on a geological time scale. The evolutionary effective population size (Ne) is estimated from mtDNA data to be between 45 000 and 60 000, a value that exceeds current global census estimates of 26 000 to 43 000 adult females.

The relationship between reproductive status and reproductive physiology was investigated in male Damaraland mole-rats Cryptomys damarensis, an eusocial rodent that exhibits a marked reproductive division of labour. Testicular anatomical and histological morphometrics, selected sperm motion parameters and measurements of circulating plasma testosterone were studied in 44 males (17 reproductive and 27 non-reproductive). Reproductive males were significantly larger than non-reproductive males. Testicular mass of reproductive males, corrected for body mass, was significantly larger than in non-reproductives. However, corrected testicular volume did not vary significantly between the two groups. Circulating plasma testosterone concentrations of reproductives and non-reproductives were not significantly different (reproductive males 201.5 ± 56.5 pg/l vs 187.5 + 91 pg/l for non-reproductive males). The quality of sperm was measured by the percentage of spermatozoa produced and the amount of immature sperm, and differed between the two groups. Reproductive males produced a greater proportion of motile sperm (77.8%) than non-reproductives (56.3%). Non-reproductive males were characterized by a greater proportion of immature sperm in the epididymis (79%) than the reproductives (25%). Interestingly, the spermatozoa of reproductive males were characterized by a greater percentage of head and tail defects. Oligospermia may be the result of a reduction in circulating follicle stimulating hormone, which acts upon the Sertoli cells of the seminiferous tubules, that in turn may be due to a lack of an opportunity to mate while in the confines of the colony in this obligate outbreeder.

The following Applications were published on 31 March 1999 in Vol. 56, Part 1 of the Bulletin of Zoological Nomenclature. Comment or advice on any of these applications is invited for publication in the Bulletin and should be sent to the Executive Secretary (I.C.Z.N.), c/o The Natural History Museum, Cromwell Road, London SW7 5BD, U.K. (e-mail: [email protected]).