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.

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.

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.

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.

This paper reports the capture of seven adult Pipistrellus nathusii including a lactating female mist-netted in July 1997 in Varese province (northern Italy). This record represents the first identification of a breeding female Nathusius' pipistrelle in the south part of the Alps. Other data on the reproduction of this species in Europe are discussed in order to reconsider its distribution and breeding sites.

Seasonal regression of testes and epididymides is described for 161 mature harbour porpoises Phocoena phocoena, L. from the Bay of Fundy and Gulf of Maine from June to December 1984–1995. Based on histological appearance and size of gonads, testes are fully active from late June until at least the end of July, spanning the estimated period of conceptions. During testicular regression, spermatocytes and round spermatids disappeared first from the lumina of seminiferous tubules, followed by the gradual disappearance of spermatozoa. Ultimately, all signs of spermatogenesis were absent, but tubules retained an alternating lining of Sertoli cells and spermatogonia. Testicular and epididymal mass, testicular length and seminiferous tubular diameter decreased approximately 3.5, 1.5 and 1.5 times, respectively, from peak production to full regression and this decrease was best described by a quadratic function. During early July when most females are ovulating, all males had active testes; variation in the degree of regression among males increased as the season progressed. This may reflect a trade-off between the costs of maintaining active testes at 4% body mass and the probability of successful fertilization. Testes are completely regressed during the winter, suggesting that few reproductive opportunities exist during this season. Unlike some other odontocete species, testicular mass of porpoises is a good indicator of breeding season.

We examined intra- and inter-litter variation in larval life-history traits in relation to maternal weight and date of larval deposition in a population of fire salamanders Salamandra salamandra terrestris in north-western Switzerland. We also examined whether the timing of larval deposition by female fire salamanders is an adaptive strategy to the changing conditions of a temporary brook. Litters differed in mean weight at birth, weight at metamorphosis, and duration of the larval period. Mean weight at birth tended to be larger in litters deposited later in the season than in those deposited earlier. Large neonates reached metamorphosis more rapidly than small ones. A short larval period resulted in a small size at metamorphosis, indicating a fitness trade-off between duration of the larval period and size at metamorphosis. Within litters, successively-born larvae tend to decrease in body size, especially in litters with a relatively large variation in weight at birth. The results suggest that environmental factors such as floods or drying out of the brook may influence the timing of larval deposition.

In this study 529 fallow deer fawns were captured and weighed at Doñana National Park, Spain. An annual index of male-biased maternal investment (MBMI) was calculated, and this index was found to vary in relation to environmental factors. Thus, the level of MBMI was sensitive to fluctuations of autumn rainfall and the male-biased maternal investment carried out by mothers in the previous year (MBMIP). Our results reveal that those factors related to the female's body condition at the beginning of gestation have a high contribution to the variation of differential pre-natal maternal investment. It has been hypothesized by other authors that male-biased maternal investment is limited by the level of total maternal expenditure and these authors classified the fallow deer as a species near to its maximum reproductive effort, in which no sex-biased maternal investment exists. Our study reveals that male-biased maternal investment in fallow deer does exist and supports the hypothesis that sensitivity of maternal investment to environmental conditions could be expected to occur in species with high reproductive effort and sex-biased maternal investment.

An alternative to the cold-climate model for the evolution of viviparity is that the impetus for the initial transition from oviparity to viviparity is not an increase in the duration of egg retention but a shift in the location of nests to more superficial and thus warmer locations in the soil profile as temperature declines with increasing altitude or latitude. Shallower nest placement, however, would lead to increased egg mortality as a result of physiological stress or predation, and enhanced egg mortality would thus provide the initial benefit of extended egg retention. To test this hypothesis, I examined the thermal biology of three species of Sceloporus lizards living at high altitudes: S. virgatus (1800 m), S. aeneus (2800 m), and S. bicanthalis (3200 m). The oviparous S. virgatus and S. aeneus females laid eggs at depths of 6 and 2 cm, and mean body/nest temperatures were 24.6/25.2 °C and 19.9/20.8 °C, respectively. Because the initial increment in the duration of egg retention is presumably short, females of these oviparous species cannot initially keep their eggs appreciably warmer than they would be in nests. In contrast, mean temperatures of simulated nests (17.6 °C) of the viviparous S. bicanthalis were similar to the 17 °C low temperature threshold for development, and temperatures in some nests fell below freezing at night and rose to lethal levels during the day. Mean body temperatures of S. bicanthalis females were 20.1 °C; eggs retained during the entire developmental period would hatch 17 days sooner than they would if laid in a nest. Extended egg retention at the highest elevation site would thus provide two benefits: reduced mortality of eggs and accelerated development relative to that in a nest. These benefits, however, accrue because of the initial shift of nests from deeper to more superficial depths in the soil profile.

Behavioural factors that are likely to contribute to the coexistence of tiger Panthera tigris, leopard P. pardus and dhole Cuon alpinus, were investigated in the tropical forests of Nagarahole, southern India, during 1986–1992. Examination of predator scats and kills were combined with radiotracking of four tigers, three leopards, and visual observations of a pack of dhole. The three predators selectively killed different prey types in terms of species, size and age-sex classes, facilitating their coexistence through ecological separation. There was no temporal separation of predatory activities between tigers and leopards. Hunting activities of dholes were temporally separated from those of the two felids to some extent. Rate of movement per unit time was higher for leopards compared to tigers during day and night. In general, the activity patterns of predators appeared to be largely related to the activities of their principal prey, rather than to mutual avoidance. The three predator species used the same areas and hunted in similar habitats, although tigers attacked their prey in slightly denser cover than leopards. Both cats attacked their prey close to habitat features that attracted ungulates. There was no evidence for inter-specific spatial exclusion among predators, resulting either from habitat specificity or social dominance behaviours. Our results suggest that ecological factors, such as adequate availability of appropriate-sized prey, dense cover and high tree densities may be the primary factors in structuring the predator communities of tropical forests. Behavioural factors such as differential habitat selection or inter-specific social dominance, which are of crucial importance in savanna habitats, might play a relatively minor role in shaping the predator communities of tropical forests.

Toe-pad development in Phyllomedusa trinitatis is described using light microscopy, SEM and TEM. Pad development in forelimbs was slightly in advance of hindlimbs. The first sign of a difference between pad (ventral) skin and dorsal skin occurred at Gosner stage 37 as a convolution of the basal side of the epidermis. By stage 39, pad basal cells were elongated in shape, with highly convoluted basal sides, whereas the dorsal epidermis had a basal layer of cuboidal cells with relatively straight bases. Mucous glands developed from pad epidermis earlier than at the dorsal side, and penetrated deeply into a matrix-rich dermis with a sparse cell population. Specialization of digit tip shape first became apparent at stage 38, with appearance of the distal circumferal groove. Widening of toe tips occurred at stage 39. Surface cells of the digital pads began to be shed by stage 40, in advance of epidermis elsewhere. Specialized pad surface cells were fully developed by stage 46, the end of metamorphic climax. During growth to adulthood, pads increased in overall area, but pad surface cells did not alter their dimensions. However, pad epidermis did become several cell layers thicker, much more so than in most other species described so far. Pad cells also had a surface area higher than in many other described species. The value of developmental studies in aiding our understanding of the multiple origins of adhesive pads in different anuran lineages is discussed.