The winter home ranges, movements and density of the jay Garrulus glandarius in the Maremma Natural Park (Tuscany, Italy) are presented, and compared with those already known for the other seasons. The movements of jays were studied for short periods over 6 years by radiotelemetric techniques (26 home ranges), direct observations of movements from vantage points, and transect counts. Summer and autumn ranges were much larger than spring and winter ones. Incremental area plots and auto-overlap analyses showed that, on average, spring ranges increased in area with time without shifting, whereas winter ranges were rather stable. In both periods, however, some birds moved as floaters since the degree of range auto-overlap decreased significantly with time. In winter and spring, range sizes of jays inhabiting different habitats were significantly different, being larger in sites with higher habitat heterogeneity. The structure of home ranges was variable in all seasons; birds showed jointed and disjointed ranges, with one or more activity centres, in all the possible combinations. In every season the average degree of range overlap between jays caught at the same site was rather high and overall actual overlap, when non-tagged birds were also considered, was even higher. No territorial behaviour was ever observed. During summer jays moved into the pinewood for the greater part of the day to collect cicadas, Cicada orni, and returned to the maquis in the evening. During autumn birds regularly moved within the maquis or from the maquis to the pinewood to cache oak (Quercus ilex) acorns. No regular long movements between habitats were observed during spring and winter. Direct observations and analyses of pellets suggested that food was abundant and highly diversified throughout the year. Thus, seasonal movements and home ranges were flexible and mainly controlled by food availability and its distribution in space and time.

The winter home ranges, movements and density of the jay Garrulus glandarius in the Maremma Natural Park (Tuscany, Italy) are presented, and compared with those already known for the other seasons. The movements of jays were studied for short periods over 6 years by radiotelemetric techniques (26 home ranges), direct observations of movements from vantage points, and transect counts. Summer and autumn ranges were much larger than spring and winter ones. Incremental area plots and auto-overlap analyses showed that, on average, spring ranges increased in area with time without shifting, whereas winter ranges were rather stable. In both periods, however, some birds moved as floaters since the degree of range auto-overlap decreased significantly with time. In winter and spring, range sizes of jays inhabiting different habitats were significantly different, being larger in sites with higher habitat heterogeneity. The structure of home ranges was variable in all seasons; birds showed jointed and disjointed ranges, with one or more activity centres, in all the possible combinations. In every season the average degree of range overlap between jays caught at the same site was rather high and overall actual overlap, when non-tagged birds were also considered, was even higher. No territorial behaviour was ever observed. During summer jays moved into the pinewood for the greater part of the day to collect cicadas, Cicada orni, and returned to the maquis in the evening. During autumn birds regularly moved within the maquis or from the maquis to the pinewood to cache oak (Quercus ilex) acorns. No regular long movements between habitats were observed during spring and winter. Direct observations and analyses of pellets suggested that food was abundant and highly diversified throughout the year. Thus, seasonal movements and home ranges were flexible and mainly controlled by food availability and its distribution in space and time.

Inter-male aggressive encounters were examined at three grey seal breeding colonies that differed in topography, adult dispersion patterns and operational sex ratios; North Rona and the Monach Isles (Scotland), and Sable Island (Nova Scotia). At North Rona, known males were observed over three successive breeding seasons, with a total of 275 males being individually identified. A single season's observations at both the Monach Isles and Sable Island provided data on 53 and 80 individual males respectively. Cardinal dominance ranks were computed for 68, 92 and 112 males on North Rona in each season respectively, 37 males on the Monach Isles and 68 males on Sable Island. All sites showed close approximation to dominance hierarchies when considering only interactions resulting in a clear outcome (wins), with less than 10% of interactions resulting in reversals. Measures of variance in male mating success showed no significant differences between colonies. These results show the existence of male dominance hierarchies in colonies from both east and west Atlantic populations and at breeding sites with widely differing habitat structure, seal dispersion patterns and levels of inter-male competition, suggesting limited plasticity in the form of grey seal mating systems and limited variation in the degree of polygyny attained at these sites.

Vestigipoda maschwitzi Disney sp. nov. is described from females and larvae collected from a colony of Aenictus gracilis in Malaysia. It is the second species in this remarkable genus, the type species being associated with a different species of Aenictus in Malaysia.

The epidermal layer of the skin of the cartilaginous fish Raja clavata taken from a suitable place on the ventral side of the head was examined by light and electron microscopy. Cells of the basal layer divide and differentiate as epithelial cells of the mid-epidermis, characterized by numerous electron-dense, membrane-bound vesicles; their content is assumed to be mucus. Cells at the superficial layer of the epidermis lose these vesicles but have a palisade of mucous vesicles below the apical membrane. A modified glycocalyx coats the outer leaflet of the apical membrane.

In addition to epithelial cells, there are epidermal cells differentiated as two kinds of mucous goblet cells, sacciform cells similar to those found in teleost fish epidermis, holocrine cells with some resemblance to the club cells of teleosts but differing in their cytology, and chemosensory cells similar to those found in the oral epithelium of Raja. Merkel cells were not found. Cells that might be interpreted as ionocytes were seen but their nature was not confirmed. The epidermis is penetrated by numerous nerve fibres; swellings contain mitochondria and glycogen granules. The nerve fibres also contain 50–70 nm vesicles with an indistinct core. Cells intrusive to the epidermis include melanocytes, lymphocytes, macrophages, and several types of granular leucocyte. The cytology of the various epidermal elements is generally similar to that known in teleost fishes.

African clawed frogs (Xenopus laevis) in a South Wales pond ate a wide variety and size range of prey. Zoobenthos and zooplankton made the greatest contribution to diets, both numerically and by weight. Terrestrial invertebrates made up a small proportion of the diet numerically but a large proportion of the diet mass during the spring and summer. Nektonic prey were present throughout the year but made up a very small proportion of diet. Cannibalism was important when eggs and larvae were present in the pond. Electivity values were consistently positive for chironomids (larvae and pupae) and daphnids but were consistently negative for tubificids. In addition, electivity increased for larger sizes and pupae of Chironomus plumosus, but was low for the largest size class (> 12 mm). Electivity of other taxa showed an increase when densities of chironomids and daphnids were reduced. Mean sizes of daphnids and cyclopods were consistently larger in frog stomach contents than in the water column, indicating that predation on zooplankton by Xenopus laevis is size-selective.

Many small mammals inhabiting vegetation habitats where food resources are scattered have large home ranges with limited overlap. One way that they may effectively defend large territories is to establish dominance over the limited number of sites that provide good protection from predators, since displacement from these sites could have a very high cost to intruders. To examine this hypothesis we studied the fine-scale use of habitat and spatial dispersion of all adult male Mus spretus inhabiting a 1.1 ha grassland study site near Lisbon, Portugal, by radio telemetry, at the start of the breeding season. The location of each of the 10 males was mapped every hour, 24 h/day for up to seven days. Microhabitat characteristics were compared between a random sample of points in the study site and those where mice were found. Individual ranges did not overlap, despite the close proximity of their borders and the occupation of almost all suitable habitat, suggesting that individual dispersion was strongly influenced by the presence of neighbours; mean range size was 343 ± 95 m2. Residents covered less than one-third of their total range over 24 h, though neighbours did not intrude despite the apparent opportunities. Each male territory overlapped the territory of at least two females. Mice were neither nocturnal nor crepuscular, moving around mostly during the morning and evening. They avoided open woodland or pathways, preferring grassland sites with tall vegetation and sites where shrubs, bramble, or dead wood provided additional cover. Most fixes per male (70%) were located in one to four core areas, which represented only a tiny proportion of each range (6.9 ± 0.9%). Although exclusive defence of large complex ranges is likely to be impracticable, defence of core areas seems much more feasible. Our results thus support our hypothesis that mice may be able to maintain large exclusive ranges due to a combination of high predation pressure and a limited number of sites with sufficient ground and overhead cover. This will result in a very high risk to mice entering areas where competitors have priority of access to protected sites.

Variation was studied at 13 electrophoretically detected allozyme loci for samples of six populations of the polytypic snail Neotricula aperta; this was the first time that topotypic material from southern Laos and material from Kampuchea had been so examined. In addition, samples of all three strains of N. aperta from North East Thailand were examined and the findings compared with those of Staub et al. (1990). The samples were taken from the Mekong and Mul rivers of the Lower Mekong Basin. A small sample was also included from a γ-strain population in the Xé-Bang-Fai (XBF) river of central Laos. The γ-strain population of southern Laos and of Kampuchea has been shown to act as an intermediate host for Schistosoma mekongi.

In contrast to the work of Staub et al. (1990) significant multilocus genetic differences (Nei's D, DN = 0.6–1.2) were detected between the three strains from Thailand and no cryptic taxon, that included both α- and γ-strains could be demonstrated. However, there was agreement with the 1990 report in that the β-strain was divisible into two new taxa, with a reduction in heterozygote deficiency, although the genetic distance was not marked (DN= 0.12). Significant genetic distances were found between γ-strain snails from the type locality and β- and γ-strain samples from North East Thailand (DN = 2.0 and 1.5, respectively). On the basis of genetic distance measures, the Β-strain is probably a sibling species of N. aperta and the γ-strain of North East Thailand may also be a separate species. The population at XBF appears to be N. aperta s.s. The public health implications of the findings are discussed, particularly in the context of Mekong river water resource development.

The impact of food competition from the red fox Vulpes vulpes on the breeding density of the goshawk Accipiter gentilis was studied in a 650 km2 area in southern Norway by investigating the density of goshawks and their grouse prey before, during, and after a period when the red fox population was low because of an epizootic of sarcoptic mange Sarcoptes scabiei. The number of goshawk pairs per 100 km2 was approximately nine/year in the 1950s, three/year in 1972–75 and in 1980–85, and four/year in 1988–91. In each of these periods, nesting territories of goshawks were regularly spaced. There was a positive correlation between the breeding density of goshawk and the population size of grouse. Both grouse numbers and goshawk breeding density increased at the same time that fox populations declined in the 1980s, while the re-establishment of the fox population in the 1990s was associated with decreases in grouse and goshawk numbers. During the partial absence of red foxes, there was a continuously high grouse population. It is concluded that the red fox may influence the goshawk breeding density negatively by limiting the numbers of grouse.

Yellow-bellied marmots Marmota flaviventris in the East River Valley of Colorado were live-trapped and individually marked annually from 1962 through 1993. These pooled data were used to produce a demography and life table for these years. Females had significantly better survivorship than males beyond the first-year age class, and the sex ratio became progressively female biased. The major mortality factors of predation and unsuccessful hibernation acted evenly on all age classes as shown by the constant rates of survivorship. The rate of senescence indicated that the probability of mortality did not increase with age. Females produced litters from ages 2 to 10 years. Mean litter size was 4.1 and did not differ among age classes. The female generation length of 4.49 years was 2.4 times the life expectancy and the median survivorship. The net reproductive rate (Ro) was 0.67, yet the population did not continually decline; adjustments to these data increased Ro to 0.85. Reproductive values (Vx) were approximately equal across the reproductive age classes. The polygynous mating system is both cause and effect of the demography. Marmot population size is affected by weather factors that influence reproduction and survival, by predation, and by movement into and out of the study area.

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.

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.

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.

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: [email protected])