The sugar glider Petaurus breviceps is generally considered to be a polygynous, group-nesting species. However, recent captive studies have indicated that dominance hierarchies and shared codominance amongst males formed when males were housed in multiple-male, multiple-female cages with male-biased sex ratios. This study uses data from sugar glider groups in natural populations to assess the probability of male dominance hierarchies and the opportunity for codominant father–son coalitions. Nesting groups of sugar gliders were found to have female-biased sex ratios ranging from 1:1.5 to 1:2.7 males:females. The dispersing sex was male – there were four records of recruitment into the natal group, all of which were female. Only one example was found of a long-term adult male association between a father and putative son, which did not occur in the natal group of the son. The evidence suggests that though father–son associations may occur, the opportunities for male dominance hierarchies or male coalitions are rare in sugar glider nesting groups in the natural environment.

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.

Body sizes of European mink (Mustela lutreola L.), polecat (M. putorius L.) and American mink (M. vison Schreber) were studied over a 10-year period in an area of north-eastern Belarus, before and after the invasion by American mink, and data are presented on interspecific interactions. On arrival in the study area American mink males were larger than males of European mink and polecat, and American mink females were larger than females of the other species. After arrival of the American mink its mean body size decreased, whilst the resident male and female European mink and female polecat increased as measured in absolute mass, length and relative mass. The observations suggest a strong character convergence most plausibly explained as a response to the invading exotic by the residents as well as in the invading species itself, whilst a divergence had been expected. There was no evidence to show whether these differences were genetically based. The body size data are consistent with the hypothesis that European mink, and to a lesser extent polecat, are responding to direct aggression from American mink (rather than merely competing for resources), with the smaller individual European mink being more likely to disappear first. We provide direct evidence for the aggressive nature of inter-specific relations from observations using radio-tracking: all observed inter-specific interactions were aggressive, significantly more so than intraspecific encounters, causing the European mink to flee, and several left the study area altogether. Implications for niche theory and for conservation management are discussed.

The anatomy of the gut and the fine structure of the foregut and midgut of the nymphal, subimaginal and imaginal stages of C. dipterum are described. A new description is given of the nymphal foregut–midgut junction and its relationship to peritrophic membrane formation. Although the mouthparts are lost at the end of the nymphal stage, and the structure of the gut undergoes extensive and often degenerative changes both during and after each of the moults to subimago and imago, the structure of the subimaginal and imaginal gut nevertheless suggests that the gut is still performing some active function during both adult stages. This is also suggested by the persistence in subimagos and imagos of rhythmical waves of midgut contraction, an energetically expensive process for an animal which has ceased to feed. Although a very occasional uptake of fluids by imagos has been observed, it has been shown, by the use of a fluorescent stain, that fluid which disappears from the mouth region is most frequently being spread as a very thin film over the body surface rather than entering the gut. Frequency of midgut contraction has been measured in resting subimagos and imagos of C. dipterum and C. simile, in imagos of C. dipterum during and after being held in a dry atmosphere, in ovipositing imagos of C. dipterum, in ejaculating male imagos of C. simile and Ecdyonurus venosus, and after successive bouts of flying by E. venosus. Previous claims that the midgut contractions either control or affect oviposition and sperm ejaculation have not been substantiated. The possibility of a key relationship between the midgut contractions and the need for rapid transport of metabolities is discussed.

The Indian false vampire bat Megaderma lyra produces a single young under captive conditions, which is altricial at birth. Empirical growth curves were derived by measuring length of forearm, body mass and length of the total gap of the fourth metacarpal–phalangeal joint. Length of forearm and body mass followed a linear pattern of growth until day 28 and subsequently reached stability. The length of the total gap of the metacarpal–phalangeal joint initially showed a linear increase up to 4 days, followed by a linear decrease until 34 days when it closed. A quantitative method of estimation of age was derived from values of length of forearm and length of the total gap of the fourth metacarpal–phalangeal joint during the preflight (first 28 days) and postflight stages, respectively. Width of the 95% confidence level was ± 1.2 days at a mean length of forearm of 51.6 mm, and ± 0.07 days at a mean length of the total gap of the fourth metacarpal–phalangeal joint of 1.89 mm. Initiation of flight occurred 24 days after birth. At 28 days of age, young were able to forage on their own. There was no significant difference in the growth pattern of young held in captivity compared to that of young grown under natural conditions.

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.

We measured sprint performance of phrynosomatid lizards and selected outgroups (n = 27 species). Maximal sprint running speeds were obtained with a new measurement technique, a high-speed treadmill (H.S.T.). Animals were measured at their approximate field-active body temperatures once on both of 2 consecutive days. Within species, individual variation in speed measurements was consistent between trial days and repeatabilities were similar to values reported previously for photocell-timed racetrack measurements. Multiple regression with phylogenetically independent contrasts indicates that interspecific variation in maximal speed is positively correlated with hindlimb span, but not significantly related to either body mass or body temperature. Among the three phrynosomatid subclades, sand lizards (Uma, Callisaurus, Cophosaurus, Holbrookia) have the highest sprint speeds and longest hindlimbs, horned lizards (Phrynosoma) exhibit the lowest speeds and shortest limbs, and the Sceloporus group (including Uta and Urosaurus) is intermediate in both speed and hindlimb span.

Development of the sensory lines, dermal skull bones, neurocranium, quadrate, mandible and hyoid apparatus of the Holocene Australian lungfish Neoceratodus forsteri is described, beginning at stage 40, before the formation of any skeletal elements, until skull development is complete in the sub-adult fish. The sequence of the initial development of skeletal structures of the head and shoulder girdle reflects the need to feed and to acquire efficient gill respiration. The appearance of the neurocranium and dermal bones of the skull follows the formation of teeth, jaw bones and the cartilaginous quadrate, and the opercular bones, the skeletal elements directly associated with these functions. Dermal skull elements are closely related to the distribution of the sensory line system of the head. Each bone of the normal developing skull roof arises from a single centre of ossification, forming in a collagenous template secreted by mesenchymal cells. The numbers and arrangement of the skull bones found in the adult N. forsteri is the same as the pattern of bones laid down in the hatchling and juvenile, and the structures develop in an ordered and functional sequence.

The mite Parasitellus fucorum (De Geer) (Mesostigmata: Parasitidae) lives and reproduces in the nests of bumblebees. Despite its abundance on European bumblebees and its occasional invasion of honeybee nests, little is known about its basic life-history traits and dietary requirements. This paper describes the mating behaviour, oviposition and development of P. fucorum under controlled laboratory conditions, and provides observations on the dietary preferences of its life-cycle stages.

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: iczn@nhm.ac.uk).

Nutrient use by the red panda Ailurus fulgens was measured in animals fed only on their natural bamboo Bashania spanostachya diet. The project was carried out at the field observation station of Yele Natural Reserve in Sichuan, China. Two-week long trials were conducted at monthly intervals from May to November 1995. Results showed that dry matter digestibility differed significantly among seasons and between diets. Digestibilities of dry matter and key nutrients were high in summer–autumn, intermediate in spring and low in winter. Shoots were more easily digested than leaves and exhibited the highest digestibility. These variations were positively correlated with nutrient contents in bamboo. The results also indicated that the red panda poorly processed its bamboo food. This was demonstrated by the lower digestion coefficients of dry matter and nutrients, especially that of cell wall constituents. This implied that microbial digestion only played a minor role in its digestive strategy, similar to the giant panda Ailuropoda melanoleuca, another herbivorous carnivore. In addition, the transit of bamboo through the red panda gut was very rapid (2–4 h). In order to survive on this poor-quality diet, it seems that the red panda has to select high-quality items of bamboo such as tender leaves and shoots. These are ingested in large quantities (over 1.5 kg of fresh leaves and 4 kg of fresh shoots daily) that pass through the digestive tract fairly rapidly so as to maximize nutrient intake.

The small population of wild dog Lycaon pictus (n = 3 to 30) in Hluhluwe-Umfolozi Park (HUP) has declined since 1992. The survival of dogs in HUP is dependent on the reintroduction of more dogs; however, wild dog reintroduction programmes are fraught with problems and many have failed. In this paper the diet and capture success of the wild dog pack in the Hluhluwe Section, and the influence of dietary considerations on the success of the future reintroduction of wild dogs in this reserve, are investigated. Diet choice was determined from scat analysis, personal observation and field staff records. Eight ungulate prey species were identified from scat analysis: nyala Tragelaphus angasi and impala Aepyceros melampus were the most abundant ungulate species in HUP and accounted for 77% of the diet. On the whole, wild dogs included prey types in the diet consistent with a rate-maximizing foraging approach, although some prey were clearly taken opportunistically. The dogs preyed mostly on small- (> 25 kg) to medium-sized (40–90 kg) prey, while the young of large (< 90 kg) prey species or scavenged carcasses supplemented the diet during the dry season. Adult nyala were taken more frequently than other age classes, but wild dog preyed on juvenile impala more than expected. Female prey were taken more frequently than males but selection did not differ from prey population sex ratios. Prey capture success was similar to that of previous studies from both open and densely wooded habitats and the wild dogs successfully caught 48% of all prey species pursued. Results suggest that wild dogs are quite capable of adapting both their diet choice and foraging technique to the dense vegetation in HUP. We conclude that prey type, prey availability and habitat constraints on prey capture success, will not affect the reintroduction of more wild dogs into HUP.

Body size is often considered to be an important trait affecting individual fitness. In arthropods, females commonly benefit from larger size directly through increased fecundity (Roff, 1992), and males through increased mating success (Andersson, 1994). It has also been suggested that larger individuals may in general have a better survival than smaller individuals (Calder, 1983; Peters, 1983). From this suggestion it may be predicted that during stressful environmental conditions larger individuals should do better than smaller individuals.

Throughout Europe there is considerable concern about the potential impact of sawbill ducks Mergus spp. and great cormorant Phalacrocorax carbo on catches of commercial fish (reviews by Marquiss & Carss, 1994; Russell et al., 1996). A prerequisite to estimating impact is to quantify the consumption of commercially important fish by birds. This requires site-specific data on (1) bird numbers, (2) their daily food intake and (3) diet. Considerable effort has been directed at quantifying (2) and (3) and exploring the biases associated with different methods (see Carss et al., 1997 for review).

This topic formed the basis of a joint meeting with the Society for the History of Natural History on 8 December 1998.