The Macrostomata accounts for more than 85% of extant snakes and is characterized by increased mobility of the jaws and increased gape size. We used stomach contents of museum specimens and specific literature records to describe the food habits of a basal clade of macrostomatan snakes – the erycine boas (Erycinae) – with an emphasis on the North American Charina bottae. Mammals, lizards, birds, and squamate eggs composed 66%, 17%, 7%, and 5%, respectively, of the prey of C. bottae. Smaller C. bottae fed on squamate eggs and lizards, whereas larger snakes added mammals and birds to their diet, and ceased to take squamate eggs. Ten of 12 snakes with multiple prey had eaten nestling birds or mammals, and snakes that ate multiple prey were not significantly larger than those that had single prey. Charina trivirgata and C. reinhardtii also prey on mammals, whereas species of Eryx feed mainly on mammalian prey, but also eat lizards and occasionally birds. Evolutionarily more basal groups of snakes primarily feed on elongate prey, which suggests that innovations of the feeding apparatus of macrostomatans allowed these snakes to eat heavier and bulkier prey, particularly mammals. Erycines appeared and diversified at approximately the same geological time as rodents, suggesting that rodents perhaps constituted an abundant prey resource that favoured the diversification of early macrostomatans.

Two features have been considered apomorphic for the subfamily Limnodriloidinae (Tubificidae): the lobed prostate glands, which are broadly attached to prostatic pads inside the atrial ampullae, and the ‘modified oesophagus’ in segment IX. The homology of the modified oesophagus may be questioned, as it is not of the same kind in all taxa. In Limnodriloides, Smithsonidrilus, and Tectidrilus, there is a pair of diverticula, whereas in Thalassodrilides, Parakaketio, and Doliodrilus, the oesophagus is dilated to form a barrel-shaped portion. In a few species of Limnodriloides lacking diverticula, a short part of the corresponding oesophagus is swollen. A scrutiny of these features shows that they are morphologically different in several aspects: the thickness and the structure of the epithelium, the granulation, the shape of the cells and the length of the modifications. Moreover, a regular, semi-embedded blood plexus always occurs around the barrel-shaped portion but rarely around the diverticula (if present, plexus irregular), and never around the swollen part of the oesophagus. These different types of modifications fail the similarity test and thus should be regarded as independently evolved structures and coded as different characters in a parsimony analysis. Species from other subfamilies within the Tubificidae were also morphologically investigated, and modifications of the alimentary canal were found in a few of them: Ainudrilus lutulentus, Heronidrilus bihamis, H. fastigatus (all Rhyacodrilinae) and Clitellio arenarius (Tubificinae). The modification in segment VIII of Heronidrilus spp. resembles the barrel-shaped portion in, for example, Thalassodrilides, and should primarily be coded as the same character in a congruence test of homology.

Wing feather mite burdens on seven species of passerine birds (Carduelis carduelis – goldfinch; C. chloris – greenfinch; Serinus serinus – serin; Sylvia atricapilla – blackcap; Sylvia melanocephala – Sardinian warbler; Turdus merula – blackbird; Passer domesticus – house sparrow) from Portugal were assessed by the subjective semi-quantitative scoring system of Behnke et al. (1995) in order to evaluate more fully the accuracy and reliability of the technique. Our analysis indicated that in all species, scores allocated to flight feathers showed a significant positive relationship with mite counts as assessed through microscopical examination of the same feathers. However, there were differences between species of birds. Of the species examined, goldfinches and greenfinches showed the weakest relationships between assigned mite scores and actual mite numbers indicating that the technique was less accurate when applied to these species compared with the remaining five. No evidence was found that anything more was to be gained from scoring both wings, rather than just one. Feather mites (Proctophyllodes spp., Trouessartia incisa) were also detected on tail feathers, but the assessment of these feathers presented additional problems and it was concluded that in the interests of minimizing handling time of birds, tail scores had little more to offer. We conclude that scoring all the flight feathers (including all primary, secondary, and tertiary feathers) on one entire wing, but alternating between left and right wings of birds within a species, represents an acceptable compromise between sufficiently detailed examination and minimization of bird handling time in the field.

A new species of a dendrochirotid holothuroid, Thyone herberti, is described from the deep waters of Matigulu, KwaZulu-Natal, South Africa. The new species is distinct from other species of the genus in the form of its calcareous ring, in which the radial plates are prolonged posteriorly before bifurcating, and in the presence of non-rosette-like perforated rods and plates in the tentacles and the introvert. The new species increases to eight the number of southern African species currently classified in the genus Thyone.

The feeding habits and foraging modes of six species of shrew (Insectivora, Soricidae) coexisting in the forests of the Russian Far East were investigated in order to quantify levels of niche overlap and elucidate the role of body size in ecological separation. Overlap in numbers of shared prey taxa was high and Lithobiomorpha, one of the most abundant macro-invertebrates in field samples, was a major prey item of all species. The composition of different prey taxa in the diet of Sorex unguiculatus and the abundance of these taxa in field samples were positively correlated. Major differences in dietary composition and foraging mode reflected body size of shrews. While the niches of individual species were not exclusive, small species fed only on arthropods, were epigeal, and had relatively narrow niche breadths. Large species fed extensively on lumbricids and other soil-dwelling invertebrates, and were hypogeal. There were significant negative correlations between niche overlap in terms of prey composition, prey size and prey location, and increasing body-length ratios in pair-wise comparisons. Combined niche overlap was reduced with increasing divergence of body size. Adjacent species-pairs in the size series had a mean combined niche overlap of 88% compared with non-adjacent pairs of 67%. The most significant areas of ecological separation between species as a function of body size were in the dietary occurrence of small versus large prey and in the foraging mode (epigeal versus hypogeal). These findings confirm that body size has an important role in effecting ecological separation in multi-species communities where a high degree of morphological and ecological similarity occurs between members.

We tested the hypothesis that echolocating bats use landscape elements as acoustic landmarks. We predicted that bats should be able to perceive distant landscape elements using echolocation and hence change their echolocation behaviour in relation to these elements. Echolocation parameters of commuting pond bats Myotis dasycneme (Boie, 1825) were related to the bats' distance from banks of different sized canals. Pulse durations emitted while bats flew over canals of 13, 19, and 25 m wide increased successively. Interpulse intervals were equally long at 13, 19, and 25 m wide canals, but significantly longer at a 30 m wide canal. The mean interpulse interval used by bats flying along the midline of the 30 m wide canal was just sufficiently long to prevent overlap of an echo from the canal bank and a new outgoing pulse. The results indicate that pond bats perceive the canal banks by gradually adapting their pulse emissions to the distance to the banks. This suggests a role for the banks as acoustic landmarks.

We summarize the information on the diet of roe deer Capreolus capreolus found in 33 European studies. After giving a short overview of the differences between the existing studies, we compare the information for each season. We submit the information, summarized in a matrix of 83 cases on 10 food groups, to a detrended correspondence analysis (DCA) and a two-way indicator species analysis (TWINSPAN). We calculate weighted averages grouping the information by season, habitat, research method and their cross-products. The weighted averages are also used as input for a multivariate ratio analysis. Since the available food items dictate the possible diet composition we further investigate the influence of the habitat on the reported food selection. The influence of season on the diet composition is compared with the effect of the habitat, and other factors such as research method and geographical location of the study site. The review shows that there is relatively little seasonal variation in the diet composition, which is more closely correlated to the habitat than to the season.

Ball rolling in dung beetles is an energy expensive activity associated with elevated thoracic temperatures. The ability of individuals to engage in such energetically costly behaviour may be dependent on their body condition. Bilateral asymmetries arising from the interaction between an individual's genes and its environment have been hypothesized to reflect an organism's quality. A number of studies have shown that individuals with elevated levels of asymmetry perform less well under stress. We tested this hypothesis by measuring correlates of dung ball rolling speed in males and females of Kheper nigroaeneus (Coleoptera: Scarabaeidae). We found that larger beetles produced larger dung balls and rolled them faster along an experimental track. However, there was no relationship between ball rolling speed and the asymmetry of fore and hind tibia. There was also no relationship between the asymmetry of the beetle or the number of mites that it carried, and the level of mite infestation did not influence ball rolling speed.

Sequences of a mtDNA gene, cytochrome b, were used to generate a phylogenetic hypothesis for the evolution of Iberian archaeobatrachian frogs of the genus Discoglossus. Results from the inferred phylogenetic branching pattern and the sequence divergence among species and populations support the following: (1) the two endemic species from Iberia, D. galganoi and D. jeanneae are sister taxa and are reciprocally monophyletic with respect to their mtDNA; (2) the geographic distribution of these two morphologically cryptic species differs considerably from previous expectations. D. galganoi is limited to the metamorphic granitic and shale substrates of western Spain and Portugal, while D. jeanneae extends over the limestone and gypsum substrates of most of eastern Spain from the Strait of Gibraltar to the Pyrenees; (3) sequence divergence between D. galganoi and D. jeanneae averages 8.6%, suggesting that the two lineages diverged before the Mio–Pliocene boundary. We suggest that these lineages were isolated by the opening of the Betic Strait and that isolation has been maintained until recently by the Guadalquivir River Basin; (4) all specimens of D. jeanneae, from the central Pyrenees in the north to the southern end of the Iberian Peninsula have nearly identical cytochrome b haplotypes, clear evidence of a rapid relatively recent (Late Pleistocene–Quaternary) expansion of the species; (5) populations of D. pictus from northeastern Spain are highly divergent from all other Discoglossus studied and do not fall within the Iberian clade.

We explored predator specialization by examining dietary variation in the widespread North American long-nosed snake, Rhinocheilus lecontei. We examined the stomach contents of more than 800 museum specimens, and supplemented our findings with published dietary records. Sixty-six percent of 135 prey eaten by R. lecontei were lizards, 26% were mammals, and 7% were squamate eggs; teiid lizards of the genus Cnemidophorus comprised 72% (64 of 89) of all lizard prey. Ninety-four percent of specimens with food contained a single item, and all 79 prey for which we determined direction of ingestion were swallowed head-first. Among those specimens containing food, long-nosed snakes from Mexico were significantly larger, and ate a higher percentage of mammals, than specimens from the United States. Larger R. lecontei sometimes fed on larger prey, and perhaps excluded smaller prey from their diet. To assess relative trophic niche breadth for R. lecontei, we compared the percentage of lizards and of Cnemidophorus in the diet of long-nosed snakes with the percentage with which other terrestrial snakes consumed lizards as their modal prey, and with which these same snakes ate members of their preferred lizard prey genus. Although we uncovered no statistical basis for labelling R. lecontei a specialist, its diet may often be restricted to lizards and even to Cnemidophorus, and therefore recognizing long-nosed snakes as specialist predators remains a subjective decision. Our study also demonstrates that quantitative natural history can place related species in a resource use continuum, and thereby can help to elucidate the evolutionary basis for specialization.

On morphological and chromosomal grounds Pipistrellus (Arielulus) subgenus is elevated to generic rank and the recently described genus Thainycteris has been synonymized with Arielulus. Besides this taxonomic revision, a new species of bat Arielulus torquatus is described from the central mountains of Taiwan which differs from its congeners chiefly by its size and colouration.

A distinctive and geographically isolated population of red colobus monkey Procolobus badius has been discovered in the Niger Delta within what was previously believed to be a discontinuity in the distribution of the species some 1200 km across. This Delta red colobus represents a new subspecies, P. b. epieni, most closely resembling the taxon on Bioko (P. b. pennantii) in such features as black hands and feet, and lack of orange-brown tones on head and neck, but differing in having whitish arms and hair whorls above the ears. It is less similar to subspecies on the mainland to the west or east (P. b. waldroni in Ghana and P. b. preussi in Cameroon, respectively), implying a complex zoogeographical history for the species. The Delta red colobus occupies an exceptionally low lying habitat of marsh forest, and its range lies within an area that had been independently identified as a centre of primate endemism, so it may have survived climatic vicissitudes of the Pleistocene in a Delta refuge. As it is confined to an area of about 1500 km2, it is now vulnerable to increasing human pressures.

Most New World leaf-nosed bats (Phyllostomidae) are frugivores. Many of these species are sympatric and mechanisms of resource partitioning including vertical stratification and divergent foraging strategies have been described. This study investigates a previously unexplored but potentially significant factor in resource partitioning: the relationship between feeding behaviour and fruit hardness. Data summarizing ingestive and fruit processing behaviours were collected during feeding experiments from five sympatric frugivorous phyllostomid species: Artibeus jamaicensis, Dermanura phaeotis, Sturnira lilium, Carollia perspicillata, and Glossophaga soricina. Individuals were the subjects of feeding experiments that consisted of eating hard and soft fruits of similar size, shape, and mass. Variables analysed from videotapes of the experiments describe how fruits are placed in the mouth during ingestion, the frequency of head movements during biting, the number of bites used to remove a piece of fruit, and the number of chews used to process each mouthful of fruit. Results of chi-square, log-linear, R×C, and Kruskal–Wallis tests demonstrate that feeding behaviours vary significantly with fruit hardness both within and between species. Artibeus, Dermanura, and Sturnira are behaviourally specialized for feeding on relatively hard fruits. However, Carollia, and probably Glossophaga, lack these behavioural specializations. Both mechanical and ecological implications of intra- and interspecific behavioural variation are discussed. Differences in fruit handling behaviour are also used to make explicit predictions regarding interspecific variation in masticatory morphology. This study demonstrates that the relationship between fruit hardness and feeding behaviour may be an integral part of frugivore ecology. Overall, resource partitioning among phyllostomid frugivores is a result of complex interactions among and between bats and their food plants. Controlled experimental studies such as this one provide a crucial means of dissecting these complex interactions and gaining insight into the basis of frugivore diversity.

We characterized the day roost sites of four pairs and one solitary tawny frogmouth Podargus strigoides in a woodland in south-eastern Australia. The birds were equipped with radio transmitters which enabled us to locate them daily from autumn 1997 to late summer 1998. Tree species, tree size, roost height and orientation of the roosting bird were recorded. Over the study period tawny frogmouths frequented a large number of day roosts (up to 71 per pair). Birds rarely used the same roost over extended time periods and most roosts were used for less than 3 days. Mature trees with a girth of more than 0.5 m were preferred as day roosts. Tawny frogmouths exhibited a significant preference for the coarse and dark-barked stringybark trees, but other tree species such as the smooth-barked, light-coloured gums were also frequented. However, when roosting in gum trees, dead branches were preferred, presumably as these have a coarser appearance than living branches and therefore provided better camouflaging. Especially during winter, the birds showed a significant selection of branches on the northern side of roost trees presumably to maximize sun exposure. During summer, two pairs maintained a significant northerly preference, whereas the others used roosts with random orientations. Small-scale seasonal movements in the area used for day roosting were also observed, with two pairs selecting a distinct area with a south-westerly aspect during summer which appeared to have less sun exposure. Our study suggests that tawny frogmouths select roosts to (1) minimize visibility from day predators and (2) to facilitate passive thermoregulation by sun-basking.

The mammalian spleen consists of white and red pulp and serves at least the dual purpose of immunological functions and filtration, and subsequent lysis of abnormal red blood cells (RBCs) from the blood. Seals are known to have very large spleens with a mass that, when fully dilated, amounts to about 2–4% of body mass. The red pulp in these animals serves as a temporary store for large amounts of (oxygenated) RBCs, which may be released during diving. In the present study the spleens of four hooded seals, which are known to be able to stay submerged for almost 1 h and reach depths in excess of 1000 m, were examined histologically. The hooded seal red pulp was found to contain perforated arterioles that communicate with interconnected fenestrated venous sinuses through which the blood commutes with an extravascular room. It is proposed that this extravascular room is engorged with blood in response to withdrawal of alpha-adrenergic nervous tone to the splenic capsular smooth muscle, concomitant with dilatation of the splenic artery and increased splenic venous resistance. This will result in capsular dilatation and increased inflow of blood to the extravascular room, where RBCs may adhere reversibly to a mesh of reticular fibres, while the plasma fraction can escape back into circulation by way of the fenestrations. In preparation for the release of the RBCs, the opposite will happen – the capsula and the splenic artery constrict gradually, while the splenic veins dilate, and the RBCs are washed out. It is suggested that the release of the RBCs from the reticular fibres is facilitated by the release of a hitherto unknown substance, in response to beta-adrenergic nervous stimulation.

Natural nest-site selection was investigated in 50 radiocollared southern flying squirrels Glaucomys volans during spring and summer, 1994–1996, in the Ouachita National Forest of Arkansas. Squirrels nested in 226 trees in a variety of habitats at five study areas. Contrary to previous reports describing southern flying squirrels as habitat generalists, in this study squirrels showed selection in both the habitat and tree type in which nests were placed. Where it was available, mature pine–hardwood forest was selected for nesting. Young (< 15 years old) and immature (15–40 years old) pine plantations and harvested areas were avoided as nesting habitats. At harvested study areas, squirrels nested in protected riparian mature forest strips (greenbelt) along, and 10–20 m either side of, intermittent creeks and in adjacent mature forests. Squirrels constructed only outside nests in pine trees. In mature pine–hardwood forest, pines were used for outside nests more frequently than hardwoods; in greenbelt habitat, pines and hardwoods were chosen equally for outside nests. Both outside and cavity nests were found in hardwoods; standing dead trees (snags) contained only cavity nests. Snags were selected over hardwoods for cavity nesting in both mature pine–hardwood forest and greenbelt habitat. All hardwood species and all decay classes of snags were used for diurnal nesting in greater frequency than expected. Considering both cavity and outside nest-site selection, pines were used less than expected. Results suggest that mature forests are optimal flying squirrel nesting habitats and should be retained adjacent to harvested areas to provide resources to squirrels abandoning stands after disturbance. Within harvested areas, nesting habitat can be substantially improved through the retention of overstory hardwoods and snags, as well as protection of mature forest strips along drainages.

Green toads from Sardinia are on average 30% longer and twice as heavy as those from the Italian Peninsula. The skeletochronological analysis of an island and a mainland population showed that differences of size were not a consequence of a longer lifespan of island toads, but of their higher growth rate in the pre-adult stages of life. The effects of these differences of size on the acoustic communication system of the species were analysed. Significant differences were observed in both spectral and temporal properties of the calls. The longer size of insular toads resulted in a reduction of 0.24 kHz of the fundamental frequency. Differences of temporal properties were mostly due to the different thermal conditions of calling males: with respect to mainland toads, island green toads were generally active at lower water temperatures and, at the same water temperature, they had proportionally lower body temperatures.

Seventeen populations of T. hermanni in Greece differed substantially in mean adult body size, over a range of about one and a half times in length and three times in mass. Females were the larger sex in all populations; the degree of sexual size dimorphism did not vary with mean body size. The proximate cause of the variation of body size among populations was differences in the duration of growth, rather than egg or hatchling size or the growth rates of juveniles. The age at maturity (α) increased with body size in the 17 populations, while the Bertalanffy growth constant (k) decreased with body size. The quantities αM and M/k (where M is the instantaneous mortality rate) were invariant with body size, suggesting that differences between populations were adaptive rather than the result of short-term disturbance. Body size was greater in cooler areas, and increased with both latitude and altitude. This pattern is opposite to that found in most ectotherms (the reverse Bergmann's rule), and to that which occurs between tortoise species. Several hypotheses about the possible ultimate causes of variation of body size were rejected, including adaptation to long-term habitat disturbance (land use), character displacement, social factors, energetics, thermoregulation, r-K selection, the length of the season available for incubation, or differences in juvenile mortality. The most likely ultimate cause of size variation between sites is differences in adult mortality, the correlation with environmental temperature being through the frequency of fires.

The fossil of a second primitive snake from Cretaceous marine sediments is identified and redescribed: Pachyophis woodwardi Nopcsa. This snake was similar to Pachyrhachis in having pachyostotic vertebrae, a slender neck and a small head. However, Pachyophis differed from Pachyrhachis in being even more aquatically adapted: the mid-dorsal vertebrae and ribs are more swollen (pachyostotic), the body was more laterally compressed, and the dentary contains more teeth. The hindlimb (well developed in Pachyrhachis) cannot be confirmed as present or absent in Pachyophis. A cladistic analysis demonstrates that Pachyophis and Pachyrhachis form a clade. This grouping, here termed the Pachyophiidae, forms the most basal group of snakes so far known and is the sister group to all other well-known snakes.

Constraints on time and energy suggest that animals often will have to forgo one activity in favour of another. In the field, gravid garter snakes, Thamnophis elegans, eat little or nothing, especially late in pregnancy. In addition, they spend considerable time basking, presumably to aid development of their progeny. Apparently, therefore, a conflict exists between feeding and behaviours related to gestation. Alternatively, low feeding levels in the field might reflect reduced ability to catch food while gravid, or anorexia, attributable either to reduced space in the gut or to physiological suppression of appetite. In this study, by supplying abundant food in the laboratory, we test the hypothesis that gravid females are anorexic; we also examine the interactions among feeding, thermoregulation and reproductive condition. Typically, gravid females, whether fed or not, spent most of their time at the warm end of a gradient, as did fed non-gravid snakes; unfed non-gravid females spent significantly less time at the warm end. However, gravid snakes, even when presented with food ad libitum, ate less than non-gravid snakes, suggesting that they are anorexic while pregnant. Feeding and thermoregulatory behaviours of gravid females changed around the time of parturition (increased feeding, reduced warming rate). Comparable changes are seen in animals in the field, and are correlated with changes in movement pattern. Evidently, the tendency to eat little food is carried over into the laboratory, even when apparent proximate causes of the behaviour are removed. Although we cannot distinguish clearly between the two potential causes of anorexia, the evidence slightly favours physiological suppression of appetite. Physiological suppression of appetite while gravid would ensure that the urge to forage rather than thermoregulate does not diminish the chances of present reproductive success. By contrast, non-gravid snakes, faced with a shortage of food, lower their body temperature and reduce their metabolic costs.