Until the mid 1970s only a few grey seal Halichoerus grypus pups were born each year on the Isle of May, Scotland, but 1408 pups were born there in 1994. We examined changes in overall site use, individual pupping site fidelity and success in relation to local population density and topography. The area of the island used by seals for breeding has increased as the population increased. Between 1988 and 1994 an index of the proportion of the island's northern area occupied by seals increased from 0.48 to 0.65, while the average population density in these occupied areas decreased over the same period. Although seals have begun to breed in southern parts of the island that were unused previously, other apparently suitable breeding areas on the island remain vacant. Fine scale digital elevation models were constructed using a GIS to evaluate the topographic characteristics of occupied areas and assign topographic ‘costs’ to areas used by seals for breeding on the Isle of May. Seals were associated generally with areas close to the numerous access points from the sea. New areas occupied in the later years of the study had a higher topographical ‘cost’ than the traditional sites. Thus, in an expanding colony such as the Isle of May, areas colonized early in the colony's history were those close to access points and/or standing water and at low elevations. Subsequent expansion resulted in an increase in the areas occupied by seals, but these newly colonized areas were less suitable, and their occupiers were subject to increased topographic ‘costs’. Pup mortality rates were similar in areas of high and low breeding density. Aggressive behaviour between breeding females is the likely mechanism which acts to limit local animal density. Mothers marked at the Isle of May since 1987 returned there to breed with few exceptions, and most females that returned were faithful to their previous pupping sites (median distance between sites used in consecutive breeding seasons = 25 m). Site fidelity persisted even when a previous pupping was unsuccessful and most individuals' pupping locations did not change gradually with time. Comparison with other colonies suggests that the spatial scale of site fidelity is related to the scale of topographic variation within the breeding site.

The microenvironments of decaying logs support a large invertebrate fauna, but are vulnerable to the effects of logging and land-clearing. We present an analysis of the relationship between a number of environmental variables and the occurrence and abundance of the onychophoran Euperipatoides rowelli within decomposing logs in a forest in south-eastern Australia. Aspect of slope is strongly associated with most of the environmental variables and is a good predictor of both presence and abundance of animals in logs; south-easterly slopes show higher levels of log colonization, larger populations within logs and a larger median weight of both males and females than north-westerly facing slopes. Degradation state of logs, log length, presence of termites and shrub cover are also associated with the presence of onychophorans, while log volume shows the most marked association with abundance. Euperipatoides rowelli prefers wetter logs, although there is considerable overlap between relative water content of logs with and without onychophorans. Log degradation state, an important factor in the presence of animals, is associated with years since felling, and our data indicate that logs become capable of supporting large populations of E. rowelli after a minimum of 45 years of decay. Thus future logging practices have important implications for the maintenance of suitable log environments for this species, and this result may be generalized to other log-reliant fauna.

Vocalizations of Boophis madagascariensis (Rhacophoridae) males were recorded in a mid-elevation rain forest in eastern Madagascar. Call notes made by males of this species were classified into 28 types. This represents the largest known call repertoire of any amphibian. The calls range widely in spectral characteristics from a narrowband, nearly pure-tone to broadband ‘rip’ notes, to even broader band, pulsatile ‘iambic’ notes consisting of up to 23 pulses. Even considering all ‘iambic’ notes as variants of one type, there remain eight distinct call notes produced by this species. Morphological analysis of the vocal musculature of B. madagascariensis revealed no obvious adaptations for unusual glottal flexibility or function. Playback studies using a subset of the call notes as stimuli were carried out in the animals' natural habitat to determine the functional significance of several of the call notes. At the lowest playback levels, there was a significant tendency for males to produce rip notes in immediate response to either rip or iambic note stimuli. At the higher playback levels, we identified one sequence of iambic notes that consistently evoked a significant iambic note response from males. A permutation test on call note transitions during spontaneous calling revealed that call note pairs occurred inconsistently and unpredictably. The evolutionary significance of an extended vocal repertoire, matched counter-calling and a random call note production scheme is discussed.

Several decapod groups independently colonized freshwater and terrestrial habitats and became independent from the sea. These invasions were accompanied by analogous reproductive and developmental traits such as large eggs and an abbreviated, lecithotrophic development. Here, we present the first empirical study on the evolution of reproductive and developmental traits that accompany the invasion of land by crabs. As crucial steps in the colonization, we identify the transitions of the larval nursery, first, from the marine plankton into landlocked-brackish nurseries and, second, into fresh water. During these invasions, the early life-cycle stages were facing new ecological conditions and selective agents. We test hypotheses on the evolution of egg size and the mode of development in relation to the larval ecology of recent species and draw conclusions on their evolutionary past. As a model we focus on the genus Sesarma, that colonized Jamaica relatively recently and comprises species with a larval development in marine, brackish and freshwater habitats. In addition, we compare representatives of the crab genera Armases, Sesarma and Uca that invaded brackish-nursery habitats independently. The analysis reveals that in each genus the transition from marine to brackish nurseries resulted in fewer and larger eggs, an abbreviated development and higher endotrophic potential of larvae, and a wider tolerance to physicochemical stress (salinity). Size at metamorphosis, however, did not change in brackish species, suggesting that it is constrained. Within the Sesarma-lineage, egg size increases considerably from marine to freshwater species. The duration of embryonic development, the size and endotrophic potential of larvae are positively correlated, but the duration of the larval phase is negatively correlated with egg size. Hypotheses suggesting that large eggs evolved as a response to limited food or intense predation are inadequate to explain the initial egg-size increase in brackish species. We suggest that the specific abiotic environment of the brackish nurseries ultimately selected for increased egg size. These particular larval nurseries of brackish species of Armases, Sesarma and Uca are nutrient rich but ephemeral habitats with unfavourable physicochemical conditions, which strongly favour a swift larval phase and possibly large body size and higher salinity-stress resistance of larvae. The reason for the further and substantial increase in egg size in freshwater species remains unknown. The ‘food-limitation’ hypothesis derived from laboratory experiments, however, is inadequate to explain this increase. Our results support general life-history hypotheses (‘safe harbour’ hypothesis) that predict the evolution of large eggs if post-embryonic stages face high risk of mortality, but not the predicted positive relationship between egg size and instantaneous egg stage mortality. On the contrary, we find a negative relationship, suggesting that larger eggs are a ‘safer harbour’ than smaller eggs. We outline a scenario for the invasion of land by crabs and propose a two-step model: as a first step, an instant shift of the larval development from offshore into landlocked-brackish nurseries, and, as a second step, from there into freshwater nurseries.

Any interpretation of archaeological animal bone assemblages benefits greatly from a knowledge of animal behaviour patterns and population dynamics, but there are difficulties in directly imposing modern data onto past, often non-analogue environments, and in assuming species-specific behaviour. This paper suggests that behavioural ecology – which stresses adaptation – provides a fruitful approach for predicting ethological details of past wild animal populations. The study focuses on the genus Gazella, whose remains are commonly found on archaeological sites in south-west Asia in the period 20,000–7500 before present (BP), and whose role in human societies has been much debated. Following a behavioural ecological method, selected data from 18 modern observed gazelle populations are summarized, compared, and the factors that influence and constrain the animals' behaviour are discussed. The potential for using the principles of behavioural ecology to predict factors such as gazelle social structure, reproductive strategies and mobility patterns in past environments is considered, and the value of such an approach for zooarchaeological interpretation is demonstrated.

Wood mice Apodemus sylvaticus were radio-tracked in an area covering three cereal fields, which was notionally divided into 5×5 m squares; each of these squares was classified to one of four habitat types (hedgerow, wheat, barley and oil-seed rape). From a sample of 79 radio-tracked wood mice, yielding 8500 fixes, we defined home-range boundaries and estimated for two seasons: (a) the extent to which each habitat was present in each individual's home range relative to its overall availability in the surrounding landscape; (b) the extent to which each habitat was used by the mice relative to its abundance within a home range. Hedgerow ranked highest in preference (as distinct from use) for all comparisons made in both winter and summer. In winter, home ranges contained significantly more hedgerow than barley and wheat, and significantly more rape than wheat. Animals also used the habitats within their home ranges non-randomly, with a significant preference for hedgerow. In summer, home ranges contained significantly less rape than other habitats. Habitats within home ranges were used at random. Seasonal patterns in habitat use appeared to be largely a response to seasonal disturbance and the availability of cover in the fields.

Distribution, habitat use and selection, ranging behaviour, diet and food supply of the stone curlew Burhinus oedicnemus were studied in a small, fragmented population at the north-western edge of its world range. Stone curlews bred on short semi-natural grassland and spring-sown arable farmland in areas with sandy soils with stones or rubble. They were most active at night and travelled up to about 3 km from the nest to forage. Individuals used a fragmented home range comprising an average of 30 ha of short semi-natural grassland, short improved pasture and spring-sown crops for foraging. Earthworms, soil-surface arthropods and molluscs were the main prey; the proportion of earthworms being lowest when the soil was dry. Breeding densities were highest on short semi-natural grassland. Stone curlews were most likely to breed on a spring-sown arable field if the crop was of a type that became tall and dense relatively late in the summer and if the field was close to short semi-natural grassland or sheep pasture and distant (> 3 km) from the nearest major road. Sparse vegetation and bare ground were the most obvious characteristics of habitats preferred for nesting and foraging.

We demonstrate that the males of the peripatopsid Euperipatoides rowelli secrete a pheromone from crural papillae, which acts as an attractant to both males and females of the species. Patterns of colonization of decomposing logs and differences in sex ratio between incipient vs established populations indicate that males are the initial dispersers and colonizers, finding suitable log habitats in an exploratory fashion, while females subsequently colonize logs. This results in a disproportionately high frequency of males in newly colonized logs, followed by a gradual increase in female proportion. We argue that females use the aggregating pheromone secreted by males to target appropriate rotting log microhabitats, resulting in a clumped distribution of females compared to a more random distribution for males among recently colonized logs. This mode of colonization reduces the time that animals, especially females, spend outside the safety of suitable logs, and the risk-taking strategy of male exploration may explain the marked sex ratio bias in favour of females in the population. Rapid and non-random dispersal may also account for the contradictory evidence of unexpectedly high rates of colonization of new logs, yet a paucity of animals in leaf litter samples. The possibility that pheromone trails play a part in the dispersal process is discussed.

Forty-eight wood mice Apodemus sylvaticus were radio-tracked over an estimated 1500 h yielding 9000 fixes. The mice were living in three contiguous arable fields, and showed that they respond to weedy microhabitat patches within superficially homogeneous crops. Plant species' abundance and the composition of the seed bank were assessed in quadrats taken in areas in which (a) mice foraged, (b) through which mice travelled, or (c) at random within each home range. Wood mice avoided foraging in areas with a high abundance of bare earth, and selected areas with a high abundance of Alopecurus myosuroides, Stellaria media, Avena fatua, Galium aparine or Bromus sterilis. The food plants apparently selected by wood mice differed markedly between months and between sexes. This may relate to the energetic and nutritional demands incurred by the contrasting reproductive tactics of male and female wood mice. There were no differences between seed bank samples taken from quadrats where the mice foraged, travelled through, or which were selected at random. Our study, the first large-scale analysis of wood mouse microhabitat preference using radio-tracking, reveals that whereas the mice do not react to heterogeneity on the scale of the mosaic of crop fields, they are greatly influenced by the dispersion of food plants within the superficially homogeneous crop itself.

Morphology of statoliths and anatomy of statocysts were studied in five species of Gonatidae, Moroteuthis robusta (Onychoteuthidae) and Galiteuthis phyllura (Cranchiidae) from the northern Bering Sea, and Todarodes pacificus (Ommastrephidae) from the Pacific waters near Japan. A special experiment was carried out in order to observe statolith mobility on the macula statica and possible endolymph flows within the statocyst in freshly caught gonatid squid Berryteuthis magister. It was found that the statolith may deviate at small acute angles around three axes running through its centre of rotation (located near the spur) without any visual damage of its attachment area to the macula. This finding enabled us to re-consider previous theories and to create a new model of the squid statocyst functioning with the statolith as detector of multidimensional movement. Two types of statolith morphology are distinguished: demersal type statoliths characteristic of near-bottom decapods, and pelagic type statoliths characteristic of all pelagic squids and not dependent on their systematic position. Phylogenetic and ecological features of the statocyst and statolith structure are established. Possible evolutionary trends in development of different types of statocysts in decapods are discussed.

The reproductive biology of the ovoviviparous peripatus Euperipatoides rowelli was investigated from field collections and laboratory cultures. The sexes have different demographics. The frequency distribution of individual weight is essentially L-shaped in females, but closer to normality for males: thus the sexes must exhibit different patterns of growth and/or mortality. Males are generally much smaller and rarer than females. The primary sex ratio seems to be 1:1 with equal investment in the sexes, while the tertiary ratio is highly female-biased. Logs with fewer individuals tend to be male-biased while well-populated logs tend to be female-biased. Males mature at 15–30% of the bodyweight of mature females. The weight frequency distribution of males without developed sperm in their tracts is strongly skewed to the lower weights, while that of males with sperm is more normally distributed, indicating that sperm production occurs as soon in life as possible. Males mature in their first year of life, if growth rates in culture may be extrapolated to the wild. In contrast to this rapid maturity in males, females may mature as late as their second or third years. Most mature females, and many prior to maturity, carry sperm in their spermathecae. After maturity, there is an approximately linear relationship between body mass and number of developing embryos. Reproduction in E. rowelli is significantly seasonal despite high individual variance, with a major bout of parturition in November–December (summer). A female can harbour one developed and one undeveloped batch of embryos in each uterus. Excesses of developed embryos in one uterus are counterbalanced by deficits of undeveloped ones, indicating that females can use their paired reproductive tracts independently. Individual females in culture can experience episodes of parturition approx. 6 months apart without re-mating, thus gestation may be 6 months or more. Sperm in spermathecae remain capable of vigorous swimming for at least 9.5 months.

This study is the first attempt to use both independent contrasts and cross-genera correlation for the family Accipitridae to see if population density and body weight are associated with other ecological or morphological variables. Using literature data on nine variables for 189 species of 35 genera, significant associations between contrasts in population density and reproductive rate and hunting method were found. Cross-genera correlation results differed because all morphological variables were negatively correlated with population density while none of these correlations was significant using independent contrasts. Contrasts in body weight were positively correlated with mean prey weight and negatively with range size. Overall, reproductive rate had the highest correlations with population density.

A small mammal survey of the Lipotyphla (Tenrecidae and Soricidae) was conducted in the montane forest of the Réserve Spéciale d'Ambohitantely, Central High Plateau, Madagascar. Species richness of this group was assessed using standardized pit-fall trap techniques in a control site of 1250 ha and four smaller forest fragments (136, 30, 12 and 0.64 ha). The forests of this reserve are highly fragmented, isolated for many decades and about 90 km from the nearest large forest block. On the basis of pit-fall captures, lipotyphlan diversity was highest in the control site with nine species, including eight endemic taxa. The number of species declined progressively with diminishing forest size. The species richness found in the control site, the largest remaining block within the reserve, is comparable to other much more extensive forest blocks at parallel elevations and with similar botanical communities. Thus, it seems that the lipotyphlan community within the control site has not experienced notable local extinctions. The introduced Soricidae, Suncus murinus, has colonized the Ambohitantely forests. However, there is no evidence of competition between this species and members of the family Tenrecidae, particularly Microgale, as has been postulated in the literature.

Populations of the Central American spiny rat Proechimys semispinosus isolated on eight small islands in Panama were sampled monthly for 1 year to examine the relationships of demography to tree species composition and forest structure. Demography was characterized by calculating seven variables from the monthly census data. Tree species composition was determined by marking, measuring and identifying all trees ð 10 cm in diameter at breast height (dbh) on each island. Forest structure (tree stature, density and species richness) was quantified by measuring seven variables at each of the 470 sampling stations. Bivariate correlations were computed between spiny rat demography and tree species composition and forest structure. To examine whether islands with more similar tree species composition or forest structure supported P. semispinosus populations with more similar demography, dendrograms based on complete-linkage cluster analysis were constructed. Spiny rat densities were correlated positively with the density of large-fruited fig trees and non-linearly to an index of forest age based on tree species composition. Spiny rat densities were not related to any structural variable. Dendrograms based on cluster analysis showed that spiny rat demography did not map onto forest structure, overall tree species composition or any group of selected tree species except figs Ficus spp. Thus, islands with more similar fig tree composition contained spiny rat populations with more similar demography. Tree species composition, which partly determines resource abundance, is apparently more important than forest structure in influencing spiny rat demography. Proechimys semispinosus has a temporally and spatially variable demography, and this flexible demography, in concert with an ability to use diverse resources, presumably promotes abundance and persistence in heterogeneous tropical forests and may contribute to the ubiquity of this rodent.

We investigated the effects of crop type on numbers and movements of wood mice Apodemus sylvaticus in field edges and in arable fields containing either winter wheat, winter barley or oil-seed rape, grown on a 3-year rotation. We also investigated the effect of habitat (field centre vs edge), and of season and year. This was done at the individual level using radio-tracking, and at the population level using live-trapping. Wood mouse population size (estimated as minimum number alive) was significantly affected by season. Wood mouse numbers also differed between crop types. Rape field centres and edges had significantly lower numbers than did barley or wheat field centres and edges. Populations were largest from April to July, when the crop was tall. In winter, significantly more mice were found in field edges compared with field centres. The patterns of movement of individual mice also showed differences between habitats and between seasons. Mice were found to move more quickly when they were tracked through rape compared with the other crops. When the crop was growing, they moved faster through field edges bordered with hedgerow than they did through wood. This pattern was reversed later in the year when the crop was tall. The distances moved during a session of tracking showed differences which paralleled those for speed of movement. Also, males tended to move faster than females. Differences between the sexes in movement patterns were affected by season; when the crop was down (in winter) females moved further than males during a session of tracking, but when the crop was growing and tall, this was reversed.

The Mongolian gerbil has been used as laboratory animal since 1935. Breeding gerbils as an isolated laboratory population for decades may have led to a domestication process whose effects include changes in brain size. Quantitative changes in testicular activity could be assumed. Comparative intraspecific measurements were performed in 34 adult males of the laboratory strain (LAB) and in males raised as offspring of wild Mongolian gerbils (WILD) caught in central Mongolia (F1, n = 16; F2, n = 17). LAB and WILD were examined in January. Testicular spermatozoa were counted, proportions of different cell types were analysed using DNA flow cytometry, and mitotic and meiotic activity was calculated from DNA histograms. Intratesticular testosterone concentrations were measured with an enzyme immunoassay. In the WILD, testicular activity was lower and varied more. The overall weight, the efficiency of spermatogenesis (sperm/g testis) and resulting total sperm per testis were significantly less in offspring of wild gerbils. This corresponded with lower levels of haploid cells, total germ cell transformation of diploid cells to spermatids and meiotic transformation of spermatocytes to spermatids. The most profound difference was found in testicular testosterone concentration: the mean level was 405.7 ± 41.2 ng/g testis in LAB vs 6.4 ± 2.0 ng/g in WILD F1. All parameters changed in WILD F2 generation compared with F1 and diminished the differences with LAB. Differences between F1 and F2 were significant for testis mass, testis/body weight ratio, percentages of haploid cells and cells in G2/M phase, both germ cell transformations and testosterone concentration. The results suggest rapid, adaptive changes of male reproductive physiology in the early offspring generations from wild populations under laboratory breeding conditions. The breeding of Mongolian gerbils in the laboratory has influenced the testicular function resulting in increased spermatogenic activity and highly stimulated testosterone production.

Examination of recent pennatulacean material collected during several cruises off the Atlantic coast of Africa has allowed the taxonomic reassessment of several taxa of veretillid sea pens that were previously poorly known. The holotype of Cavernularia elegans (Herklots, 1858) is redescribed with the result that all previous records of the species from western Africa should be considered incorrect, as the taxon is here considered to be limited in distribution to Japan. A new species of the genus Cavernularia is described and compared with its congeners and a new veretillid genus and species are described. New taxa are based on specimens from western Africa.

All 20 of the Bulwer's petrels Bulweria bulwerii of Selvagem Grande (30°09′N, 15°52′W) equipped with maximum depth gauges had dived during the feeding trips performed during the incubation period, the mean maximum depth being 2.4 ± 1.0 m (range: 1.0–5.3 m). The depth reached showed no correlation with the breeding experience of the birds, with the length of their trip or with their body size and there were no differences between males and females. Thus, the Bulwer's petrel are among the numerous Procellariiformes which perform regular but comparatively shallow dives, unlike shearwaters (Puffinus) and diving petrels (Pelecanoides) which can reach depths of several tens of metres.

Information on the biology of ‘primitive’ blind snakes can help clarify the origin of ecological traits typical of ‘higher’ snakes. We examined and dissected 360 museum specimens to obtain information on morphology, dietary habits, and reproduction of two subspecies of an African thread snake, Leptotyphlops s. scutifrons and L. s. conjunctus. These small (to 225 mm long), slender-bodied (body diameters < 5 mm) burrowing snakes are common throughout southern Africa. In both subspecies, females grow larger than males and have relatively shorter tails. Reproduction is seasonal, with vitellogenesis in spring (October), oviposition in summer (December–February), and hatching in autumn (April–May). Clutch sizes are small (1–3 eggs), and hatchling thread snakes are large relative to maternal body size. Despite the abundance of termites on the African continent, L. scutifrons feeds almost entirely on the larvae and pupae of small ants. Both races fed infrequently, and took large numbers of prey (up to 350 items) in a single meal. A shift from ‘lizard-like’ to ‘snake-like’ trophic biology is evident within the Scolecophidia: two species of North American thread snake feed frequently on a taxonomically diverse array of small prey; African L. scutifrons feed infrequently on small prey, but take large meals composed of numerous prey items; and one highly derived Melanesian typhlopid (Acutyphlops subocularis) feeds infrequently on large elongate prey. In contrast to popular theory, our data suggest that the evolutionary shift to infrequent feeding among snakes did not initially require a change from small to large prey.

Use of roosts by the golden-tipped bat Kerivoula papuensis was investigated principally in the Richmond Range National Park, north-eastern New South Wales and Mt Baldy State Forest in north-eastern Queensland, Australia. Roosts were located primarily using radiotelemetry; although others were found by light tagging, visual location and nest searching techniques. In the main study site in the Richmond Range a total of 54 K. papuensis diurnal roosts were located, 96.5% occurring in the suspended nests of the yellow-throated scrubwren Sericornis citreogularis (Pardalotidae) (93%) and the brown gerygone Gerygone mouki (Pardalotidae) (3.5%). At Mt Baldy, K. papuensis displayed greater variation in day roost selection, although 73% were in S. citreogularis nests. In both sites, day roosts were confined to the lower stratum of rainforest with a small proportion in eucalypt tall open forest with a rainforest subcanopy. Diurnal roosts were located at distances varying from 20 to 1200 m to the nearest major vegetation ecotone, ranging from along watercourses upslope to ridgelines. Diurnal roosts were predominantly occupied by single bats, with a maximum group size of eight individuals. All roosts in hanging nests were modified by the presence of a basal hole. Strong circumstantial evidence was provided that K. papuensis modified these roost structures in a manner allied to tent-making bats. A single maternity roost was located in the hollow of a rainforest canopy tree, Flindersia australis (Rutaceae).