After the introduction of myxomatosis to the U.K. in 1953, the rabbit Oryctolagus cuniculus population crashed to less than 1% of its original size (Lloyd, 1970). Since that time the population has been slowly recovering, and reached about 20% of pre-myxomatosis levels by 1980 (Lloyd, 1981; Trout, Tapper & Harradine, 1986). Between 1980 and 1986 an index of rabbit abundance was produced from field surveys, which resulted in an estimated population growth rate of just under 1% per year but there has been no objective assessment of the changes nationally since 1986.

The first successful captive maintenance of living terrestrial Geonemertes nemertines is reported. Behavioural observations are described, including the first data on diet in this genus. The species G. pelaensis is found to be a predator of small molluscs. In 1907 the Seychelles population was described as a distinct species, G. arboricola, largely on the basis of its arboreal habit. Recent field data from the Seychelles islands of Mahé and Silhouette confirm the tendency towards arboreal behaviour.

When bats emerge from colonies to feed and drink their emergence patterns deviate systematically from those expected at random (Kunz, 1974; Swift, 1980; Bullock et al., 1987; Brigham & Fenton, 1986). In particular, many bats appear to group together as they emerge, and form into ‘clusters’ or ‘outbursts’ (but see McAney & Fairley, 1988; Kunz & Anthony, 1995 for exceptions). The function of this clustering behaviour has been the topic of recent debate, with some authors favouring the hypothesis that the behaviour is an artefact of large numbers of animals moving through a restricted space (Kalcounis & Brigham, 1994) and others suggesting the behaviour has a more significant biological function such as protection from predation (Leen & Novick, 1977; Speakman, Stone & Kerslake, 1995) or information transfer (Wilkinson, 1992).

This is the first description of the otoliths (sagitta, asteriscus, and lapillus) of the European barbel (Barbus sclateri, Pisces: Cyprinidae), as well as the location, the procedure for extracting them and preparing them for age and growth studies. The otoliths were observed by light and scanning electron microscopy. With this last technique each otolith had a variable external crystalline morphology which may be related to different growth rates of the crystals. When seen through reflected light, the lapillus and the asteriscus showed opaque and translucent radial bands, and those in the lapillus were more clearly defined than in the other otolith.

In ectotherms, the size of the female correlates with fecundity and thus, males prefer large more fecund females as potential mates in some species. The idea that the extent and intensity of mate guarding are also size-related was tested in the common chameleon Chamaeleo chamaeleon. Mate guarding was studied in 43 radio-tagged females during 3 years in a population in southern Spain. The extent and intensity of male guarding of their mates varied greatly. On average, the guarding started on 20 August and ended on 2 September (mean duration = 12.6 days, range 2–44 days, n = 35; six females were not guarded). Guarding continued for some days after mating (range = 0-13 days, n = 16). Guarding intensity (mean = 65.8% of net observation time with a guarding mate, range = 23–90, n = 27) and number of guarding males (mean = 1.8, range = 1–7) also varied greatly. The extent and intensity of mate guarding was strongly influenced by female size and the guarding period after mating: large females were guarded early in the season, for longer periods, and more intensively than small ones. Large females were also guarded for longer periods after mating. The overall variation in the guarding period was due to the duration of guarding before mating which was longer for large females. To my knowledge, this is the first time that prolonged mate guarding of larger females has been reported.

This paper describes the denning behaviour of 24 feral ferrets Mustela furo on farmland, East Otago, South Island, New Zealand. One hundred and ninety seven dens were located and radio-collared ferrets were found to share dens simultaneously with other ferrets on 7.4% of 706 radio-tracking events and used dens that had been previously used by other ferrets (sequential den sharing) on 44.3% of occasions. In this particular study, ferrets were exhibiting a higher degree of sociality than has been recorded in other solitary mustelid species and therefore may not be adhering to the model of intrasexual territoriality thought to apply to other mustelid species. Den sharing may be a mechanism by which bovine tuberculosis Mycobacterium bovis is transmitted within ferret populations. Over 80% of the sequential den sharing occurred within 14 days, well within the survival span of M. bovis bacilli. Denning of infected ferrets in haybarns may pose a risk of transmission of M. bovis to livestock from hay.

Genetic variation in the pulmonate land snail Zonitoides nitidus was examined by means of allozyme electrophoresis in 17 European populations. We observed no heterozygotes, indicating that Z. nitidus consists of several homozygous multilocus genotypes (strains) probably produced by self-fertilization. Nine strains were detected. Strains appeared not to be equally distributed over the regions considered. One strain was strongly differentiated from the others, which is suggestive of a taxonomic differentiation. Anatomically, two major phally types were distinguished: euphallics, with well-developed male reproductive organs, and hemiphallics, with weakly developed male reproductive organs. Both phally types were found together in natural populations, but euphally ratios were very low (0–19%; overall mean = 7.79%) and differed between geographical regions (Belgium, Germany, and Sweden). In some populations, hemiphallic individuals were smaller compared to euphallic individuals although the difference is small and its biological significance remains to be established. We found no clear relation between phally type and allozyme data.

The European colonists of Tasmania named the thylacine Thylacinus cynocephalus a ‘marsupial wolf’ or the ‘Tasmanian tiger’ or ‘hyena’, in reference to its resemblance to large canids and the bold stripes on its rump. The largest marsupial carnivore in historic times, it was persecuted for alleged sheep killing and became extinct before its ecology was documented. We have reconstructed the likely prey size and the hunting and killing methods of the thylacine by comparing canine tooth strength and limb bone length ratios with those of extant marsupial and placental carnivores. The thylacine was probably a pounce–pursuit predator of fairly open habitats, which killed medium-sized prey (1–5 kg) that were small relative to its body size (15–30 kg), with a crushing, penetrating bite. The trophic niche of the thylacine was similar to that of smaller canids such as the coyote Canis latrans (rather than the wolf C. lupus), but ecomorphological convergence of the thylacine with canids was superficial. Phylogenetic constraint has resulted in unique patterns of tooth eruption, molar tooth and jaw geometry, calcaneum architecture, and perhaps FMT/running speed relationships in the Dasyuroidea.

Are British animals and plants being threatened by the invasion of alien species? This was the question addressed at a Scientific Meeting of the Zoological Society of London on 10 March 1998 in three talks exploring the potential impacts of invading Chinese mitten crabs in the Thames catchment (Paul Clark and Philip Rainbow, The Natural History Museum), introduced foreign crayfish (David Holdich, University of Nottingham) and alien terrestrial flatworms (Hugh Jones, University of Manchester).

The caching of fungi by red squirrels Sciurus vulgaris was investigated in commercial conifer plantations by walking transects in Kielder Forest, Cumbria and Wauchope Forest, Scotland. In 11 transects, a total of 58 fungal fruiting bodies were observed on branches in trees, consisting of four different species (49 Russula ochroleuca, seven R. metica, one R. vesca, one Colybia maculata). Fungal stores were found to be short lived and most fruiting bodies cached were gone after 2 weeks. Based on the survey findings we estimate that within an average red squirrel home range there would be a minimum of 42 cached fruiting bodies, constituting a food store of approx. 525–714 kJ.

Goniosoma longipes is a neotropical cavernicolous harvestman that exhibits parental care. Reproductive activity in G. longipes is more intense during the wet season. Mating lasts up to 3 min, and the whole oviposition process may take over 5 h. During oviposition the female may be reinseminated once or twice by the mating male. Females oviposit 60–210 eggs on the cave wall and guard egg batches for nearly 2 months, until the 1st-instar nymphs disperse. Four main factors can affect egg survival in G. longipes: dehydration, fungal attack, cannibalism, and interspecific predation. Frequency of fungal attack on egg batches was greater in the wet season and more intense near the river inside the study cave. Although egg-guarding by females failed to prevent fungal attack on eggs in G. longipes, the choice of a suitable oviposition site by the gravid female can reduce fungal attack within the cave habitat of this species. Guarding females successfully repel conspecific egg predators, but unguarded eggs are frequently consumed by adult and juvenile G. longipes, as well as cave crickets Strinatia sp. Field experiments in which females were removed from egg batches demonstrated that egg-guarding by the mother has an anti-predator role in G. longipes, with a significant positive effect on egg survival. Male G. longipes actively patrol their egg-guarding mates, and take over brood care for up to 2 weeks if the latter are experimentally removed. The degree to which male assistance can play a relevant role in parental care is still unclear for this species. Damage to the brood is regarded as a major force favouring the evolution of parental care in harvestman species. This field study provides the first experimental demonstration that egg-guarding by females affords protection against egg predation in a harvestman species.

A system of secondary vessels emerging from the primary vessels as numerous coiled capillaries has been described in numerous teleost and holost fishes. The systemic secondary vessels of the teleost Tandanus tandanus are typical of this system and are described in this study. The existence of a secondary vessel system has been postulated in the elasmobranch group. No secondary vessel origins, as seen in the teleosts, are present in the elasmobranchs Rhinobatos typus and Carcharhinus melanopterus. Vessels with a similar distribution to secondary arteries are observed but these are venous rather than arterial in nature and do not connect with the primary arteries. Like the secondary veins in teleosts, the cutaneous veins in R. typus contain blood with a low haematocrit. There is no morphological evidence for a secondary vessel system in the dipnoan Neoceratodus forsteri.

An artificial gizzard was developed to investigate the functional basis of the asymmetry of the gizzard muscles of herbivorous birds, such as the domestic goose (Anser anser). Two types of gizzard muscle morphology were modelled: asymmetric muscles that generated a translational movement; and symmetric muscles that generated a compressional movement. The extent of breakdown of grass in the artificial gizzard was estimated by measuring nitrogen loss from blades of wheat (Triticum aestivum). The effect of grit and its interaction with the two types of gizzard muscle movement were also explored. In the artificial gizzard, translational movements caused more damage to grass than compressional movements and the damaging effect of grit was greatest when there was a translational movement. This type of movement was found to be particularly important as it prepares plant material for subsequent processing by stripping the matrix cells from the fibre bundles. Without such preparation, the breakdown of grass is limited.

The theoretically optimal shape of a bat's wing changes with flight mode (Norberg, 1987; Norberg & Rayner, 1987) and several studies have shown this theory to be largely born out in practise (Aldridge & Rautenbach, 1987; Norberg & Rayner, 1987; Crome & Richards, 1988). For instance, bats with wings of relatively low surface area (high wing loading) that are also relatively long and thin (high aspect ratio) tend to be fast, straight fliers spending most of their flying time foraging or commuting in open areas such as pasture or above the forest canopy (Norberg & Rayner, 1987). In such bats manoeuvrability is improved by the possession of small, pointed wing tips to reduce drag. In contrast bats with wings of relatively high surface area that are also relatively short and wide with large, rounded wing tips tend to be slow, highly manoeuvrable fliers foraging in cluttered habitats such as woodland (Norberg & Rayner, 1987).

The following Applications were published on 30 June 1998 in Vol. 55, Part 2 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 (ICZN), c/o The Natural History Museum, Cromwell Road, London SW7 5BD, UK (e-mail: iczn@nhm.ac.uk)

In general, if populations are founded by very small numbers of individuals, low levels of genetic diversity amongst subsequent generations known as founder effects, can be predicted to occur as a result of genetic drift (Franklin, 1980; Lacy, 1997). A loss of genetic variation has been reported in several species that have experienced genetic bottlenecks because of habitat fragmentation, geographic isolation or inbreeding depression (Gilbert et al., 1990; Hoelzel & Dover, 1991; Ellegren et al., 1993; Timms et al., 1993; Wauters, Casale & Dhondt, 1994; Wauters, 1997). This loss of genetic diversity can have deleterious effects on reproductive output. For example, laboratory and captive breeding programmes provide extensive evidence of both decreased fecundity and reduced juvenile survival (Ralls & Ballon, 1982, 1986; Du Bois, Dhondt & Van Puijenbroek, 1990; Brock & White, 1992), and research conducted on natural populations of common shrews Sorex araneus has reported similar findings (Stockley et al., 1994). However, genetic evidence from some wild populations shows that highly inbred populations can survive and thrive despite low levels of genetic variability (Gilbert et al., 1990; Wayne et al., 1991; Ellegren et al., 1993). Grey squirrels Sciurus carolinensis, were introduced into Britain from eastern North America on several occasions between 1876 and 1910. Furthermore, between 1906 and 1937 grey squirrels were translocated to a variety of different locations within Britain (Middleton, 1931; Shorten, 1954). From the 1930s it rapidly expanded its range and is now ubiquitous to almost all of central and southern England, Wales and some lowland areas of Scotland (Lloyd, 1962, 1983; Gurnell &; Pepper, 1993). In view of this highly successful colonization by an invading species the grey squirrel appears to have been unaffected by any loss of genetic diversity as a result of recent population bottlenecks. We have used DNA fingerprinting (Jeffreys, Wilson & Thein, 1985a), a technique which provides a good indication of genome variability (Jeffreys et al., 1985b; Kuhnlein et al., 1990; Kunieda et al., 1993) to assess overall levels of genetic diversity in two British grey squirrel populations; Alice Holt Forest on the borders of Hampshire and Surrey in southern England and Thetford Forest in East Anglia.

How geese break down food in their gizzards was investigated using an artificial gizzard that was loaded with grass (blades of wheat Triticum aestivum) and different quantities of four types of grit; large and small quartzite particles and large and small glass beads. Measuring nitrogen loss from the grass indicated the extent of damage to the grass. It was found that grass breakdown in the gizzard was most effective when it contained a small quantity of quartzite particles. In contrast, glass beads in the gizzard often resulted in less damage to grass than if they were absent. This suggests that there is a trade-off between the damaging effect of grit on grass and the damaging translational movement of the gizzard lumen walls generated as the gizzard contracts. The damaging force produced by the gizzard is distributed across the gizzard contents. Thus with an increase in grit quantity in the gizzard, the force experienced by each grass particle will be reduced, resulting in reduced breakdown.

Many nocturnal small- to medium-sized forest mammals can be surveyed only by directly sighting or hearing each individual. This is particularly so in tropical regions. Signs (footprints, dung scratch-marks, etc.) are often not identifiable to species (similar species frequently occur together); villagers' identifications are rarely clear enough for research purposes, and the provenance of specimens in markets can rarely be established to satisfactory precision. Assessments of animal status from brief surveys are becoming increasingly important for many conservation purposes. A repeatable methodology for field assessment of the status of nocturnal mammals is needed to allow comparisons, particularly between sites.

The impact of public rights of way on badger setts was examined in the Bradford area of West Yorkshire using comparisons of 38 setts surveyed in 1985–1996 and again in 1992–1993. Badger setts were compared on the basis of whether they were still in use or not, and on the number of illegal disturbance events recorded over the study period. The number of, and distance from, public accesses did not influence sett persistence, and the least frequently disturbed setts (i.e. those with an average of one or less disturbance incidents every 2 years) were closer to a larger number of accesses. Frequency of poaching was high near to heavily disturbed setts and those no longer occupied at the later survey. Less frequently disturbed setts were associated with landowners who were unsupportive of badger conservation: it is possible that such landowners are highly protective of their land and thus incidentally reduce the frequency of poaching and other forms of disturbance. Setts in areas with formal authorized shooting were less disturbed. Setts still in use tended to be in open habitats and visible from roads and nearby dwellings. Setts in open areas were less often disturbed than those in wooded sites. Since public access may not reduce sett persistence and may even be beneficial in an area of high wilful persecution, there are implications for the management of public access.