During a zoological survey in north-west Madagascar (Sahamalaza Peninsula) we documented aspects of the natural history of Boophis occidentalis (formerly a subspecies of B. albilabris and here raised to species level). Individual age assessed by skeletochronology ranged from 4 to 11 years. Breeding behaviour was observed at a seasonal stream after heavy rainfalls: five choruses of eight to 90 males aggregated in shallow brook sections. The males emitted low frequency calls and engaged in scramble battles. Only two females were found. A couple laid a large number of eggs, attached as a single layer on submerged stones. Tadpoles reared from these eggs had the typical morphology of brook-breeding Boophis species with a 1:5+5/3 keratodont formula and a relatively flattened body. Adult males had an anteroventrally oriented cloaca, a morphological trait shared with B. albilabris. Advertisement calls were similar in general structure to those of B. albilabris recorded at Anjanaharibe-Sud. They were unharmonious and consisted of pulsed notes emitted at irregular intervals. Much lower pulse rates in B. albilabris (30–38 pulses/s) than in B. occidentalis (90–109 pulses/s) support the specific distinctness of these taxa. The combination of characters related to reproductive biology in B. occidentalis and B. albilabris is unique in Boophis. The acontinuous breeding behaviour and large number of eggs per clutch are traits found in the pond-breeding species of the B. tephraeomystax group, while larval morphology and habitat are characteristic of brook-breeding species. Available morphological and molecular data place B. albilabris and B. occidentalis into the brook-breeding Boophis radiation. The acontinuous timing of reproduction and large egg number may be secondary adaptations that allowed the species to colonize arid regions of western Madagascar.

One hundred and sixty-four museum specimens of the tree agama Acanthocercus a. atricollis were measured and dissected to examine sexual size dimorphism, reproduction and diet. Foraging mode and behaviour were also quantified in a wild population to obtain a broader picture of their foraging ecology and to test the hypothesis that tree agamas are ambush foragers. Males and females did not differ significantly in snout–vent length (SVL) or tail length; however, mature males had larger heads than females of the same body size. The smallest female showing sexual maturity was 96 mm SVL and the smallest male was 82 mm SVL. Mean clutch size was 11.3 and was positively correlated with female body size. Reproduction was seasonal and male and female reproductive cycles were synchronous. Testicular volume was greatest during August–September and females contained enlarged follicles during August–December and showed no evidence of multiple clutching. Tree agamas fed on a broad spectrum of arthropods (10 orders), including millipedes, which other lizard taxa have been reported to avoid. Gut contents were dominated numerically by ants (92%), followed by beetles (4%). Volumetrically, orthopterans (26.8%) were most important, followed by beetles (26.3%) and ants (17.9%). Compared to adults, juvenile diet by volume was dominated by ants and consisted of fewer large prey items (e.g. beetles and orthopterans). Seasonal effects in both prey diversity and volume were evident. Tree agamas are classic ambush foragers. They spent only 4% of their time moving and made few movements per minute (mean = 0.4). When stationary, adult tree agamas positioned themselves on tree trunks (34.7%), on lateral branches (41.8%) and occasionally, on the ground (23.4%). No evidence of trophic partitioning (intraspecific niche divergence hypothesis) was found and field observations revealed that males defend territories and engage in combat. This supports the idea that selection may be favouring larger head size in males, as an outcome of male contest competition.

Using museum specimens collected in Israel during the second half of the 20th century, no support was found for the hypothesis that body mass and tarsus length of chukar partridges Alectoris chukar has changed as a result of global warming. Body mass showed fluctuations during the year, reaching a maximum in late winter and spring and a minimum in summer. Bergmann's rule predicts that in warm-blooded animals, races from warm regions will be smaller than races from colder regions, and a wider explanation states that body size is positively related to latitude. Because of its topography and varied climate, Israel provides a unique opportunity to separate partly the effect of latitude from that of ambient temperature, thus testing if Bergmann's rule is related to latitude or to climatic variables. We found that body mass (and marginally also tarsus length) declined significantly with decreasing latitude in accordance with the wider explanation of Bergmann's rule, but ambient temperature explained a much smaller fraction of the variation in body mass than latitude. These results weaken the traditional explanation to Bergmann's rule that a heat conservation mechanism causes the latitudinal size variation.

North Atlantic harbour porpoises Phocoena phocoena (L.) face considerable energetic challenges, as they are relatively small marine mammals with an intense reproductive schedule and a cold-water habitat. Post-natal growth of these porpoises was described using ontogenetic allometry and body composition techniques. The cross-sectional sample contained robust calves, immature, and mature porpoises (n = 122) incidentally killed in commercial fishing operations between 1992 and 1998. Total mass and the mass of 26 body components were measured using a standard dissection protocol. Most body components grew similarly in female and male porpoises. Blubber, brain and skull were negatively allometric, while muscle and reproductive tissues exhibited positive allometry. Female heart, liver, intestine and mesenteric lymph node grew at significantly higher rates than in males. Male locomotor muscle and pelvic bones grew significantly faster than in females. High growth rates for visceral and reproductive organs in porpoises, relative to other mammals, may underlie their early maturation and support their intensive, annual reproductive schedule. Relative to other cetaceans, porpoises seem to allocate a larger percentage of their total body mass to blubber. This allocation to blubber, which is greatest in calves (37% of body mass), may provide harbour porpoises with the thermal insulation required to live in cold water. The factors influencing growth rates and differential investments in body composition seem to change at various stages of a porpoise's life. Energy allocation in porpoises seems to shift from an emphasis on developing an insulative blubber layer in young animals to preparing the body for annual reproduction at sexual maturity.

The Malay civet Viverra tangalunga is a relatively little known member of Borneo's carnivore community found throughout Peninsular Malaysia, Palawan, Sumatra and adjacent islands and Sulawesi. To investigate the basic ecology of this species and examine the potential impact of selective logging, a radiotelemetry study was carried out in the Ulu Segama Forest Reserve in Sabah, East Malaysia. From December 1995 to June 1997, home range, movement and activity data were collected on 12 study animals in a dipterocarp rain forest, and comparisons made between civets in a selectively logged and an unlogged site. Mean home-range size was 110 ha and did not differ between sites or gender. In areas of range overlap, radio-collared civets tended to avoid one another. Day beds were located on the ground and were associated with dense cover. Activity levels averaged 55% and were similar between forest types and gender. Most activity occurred from 18:00 to 07:00 during which mean activity was 81%. In a single day, males travelled further and covered a larger part of their home range than females. Roads and trails were used by both sexes, and roads were the only observed source of mortality resulting from vehicles. While density was higher in the unlogged forest, this species persists in both areas. The ability to survive in disturbed habitats might be influenced by the proximity of undisturbed habitat that served as a biological reservoir, or source of individuals to immigrate into the disturbed habitat.

Animal diets crucially affect fitness, yet many aspects of their ultimate determinants are unknown. The distribution and extent of herbivory in lizards, its evolutionary history, and ecological factors that may favour it are discussed. Most lizards are exclusively or primarily carnivorous, yet many species eat some plants and a few are almost exclusively herbivorous. Based on a literature survey of diets of over 450 lizard species, the distribution and degree of omnivory and herbivory are described. Some plants occur in the diets of slightly over half of lizard species, and plants formed 10% or more of the dietary volume of 12.1% of species, and 90% or more of the diet of 0.8% of species. The greatest percentage of omnivorous species (> 10% plant diet), over 30% in each, and highest mean percentage plant matter in the diet are in Iguanidae, Corytophanidae, Gerrhosauridae, Agamidae, Xantusiidae, and Tropiduridae. Numerous other omnivores occur in Lacertidae and Scincidae and fewer in several additional families. Herbivorous lizards (> 90% plant volume) tend to be folivorous and to possess adaptations for processing leaves, including specialized dentition for cutting or reducing leaves, elongated intestines, colic valves that slow passage of food, and intestinal flora that digest cellulose. Omnivorous lizards lacking such specializations may eat some leaves, but consume much more fruit, flowers, and seeds, plant parts that are easy to digest, likely to be very abundant seasonally, and may be highly nutritious. Some lizards eat nectar and pollen; even sap is eaten by at least one gecko. Ontogenetic increase in plant consumption and decrease in prey consumption is known, but its generality has been controversial. Such ontogeny has been demonstrated in three iguanid species, a skink, a lacertid, two tropidurids, a phrynosomatid, and two corytophanids, but it does not occur in some other species. The importance of specific foods may vary with age. Omnivory and/or herbivory have originated in many lizard families, with at least nine origins in Iguania and 23 in Scleroglossa. Origins have been rare in Gekkonoidea and Anguimorpha and common in Scincomorpha, especially in Lacertidae and Scincidae. Losses of omnivory have been much less frequent than gains. Only a few origins can account for all the herbivory in lizards. Concentrated changes tests show that there is a significant association in Lacertidae, Lacertiformes, Lacertoidea, Scincidae, and Scleroglossa between insularity and omnivory. Insular lizards may broaden their diets to compensate for limited availability of prey. Addition of other factors that reduce availability of prey, i.e. extreme aridity and cave-dwelling, to insularity, strengthened the relationship to omnivory in Lacertidae and Lacertoidea. We were unable to demonstrate a role of aridity independent of insularity, but present anecdotal evidence suggests that it may promote evolution of plant consumption. Large body size in lizards has long been associated with herbivory, and more recently, with omnivory in lacertid lizards. Using a conventional regression approach in which each species is considered to supply an independent data point, this relationship was confirmed for all lizards. Although larger species have diets with more plants, plant consumption accounts for only 9% of the variation in body length, which is not surprising given that other factors such as predation, competition, and sexual selection affect body size. The frequency of transitions body size associated with transitions to omnivory or carnivory was also examined. In Iguania, Scleroglossa, and all lizards, transitions supporting the hypothesis that omnivory favours increase in body size were significantly more frequent than non-supporting transitions. This suggests that substantial plant consumption favours evolution of larger size, probably because of the energetic considerations first presented by Pough (1973). Because actively foraging lizards move widely through the habitat to locate prey and tongue-flick to locate prey by chemical cues, we hypothesized that they may be more likely to evolve omnivory than ambush foragers, which wait motionless for prey and do not tongue-flick to locate or identify prey. The basis of this prediction is that the wider seaching of active foragers predisposes them to contact with a greater variety and quantity of plants and that chemosensory tongue-flicking used by omnivores to identify plant food might be easier to evolve in active foragers that already use pre-chemical discrimination. The prediction is supported by a significantly greater per species frequency of origins of omnivory by active foragers than by ambushers. A scenario for the progressive evolution of omnivory and herbivory from ancestrally carnivorous lizards is discussed.

Cerci are paired, sensory appendages extending from the terminal abdominal segment of crickets. While the cerci are acutely sensitive to air currents and thereby function in the detection of potential predators, they are also known to play a role in co-ordinating movements of males and females during copulation. The role of the male's cerci at four stages of the mating sequence (courtship, copulation, mate guarding and spermatophore removal) was examined by experimentally removing the cerci of male decorated crickets Gryllodes sigillatus and comparing their mating success with that of control males. The mating success of cercectomized males was significantly reduced relative to control males, primarily because of their greater inability to induce females to mount. Even when they succeeded in securing an initial mount, cercectomized males took significantly longer to transfer a spermatophore than did control males. Cercectomy had no influence on the efficacy of post-copulatory mate guarding by males, nor did females discriminate against cercectomized males by removing their spermatophores sooner than those of control males. We conclude that the primary function of the male's cerci in sexual interactions in G. sigillatus is to provide tactile stimuli to females that either elicit or guide their mounting response.

The Brazilian tree-frog Corythomantis greeningi inhabits the Caatinga, a semi-arid habitat. This species exhibits putative adaptations to a dry environment, including a flat head, co-ossification of the cranial skin, and phragmotic behaviour (retreat to crevices using the head to seal the entrance). Real frogs were compared with agar models to study water balance under simulated Caatinga conditions and to investigate the ability of C. greeningi to find small water sources. The benefits of skin co-ossification were also studied by comparing agar models with and without nail polish on the head. Tree-frogs repeatedly preferred a humid test tube out of 10 possible choices, and adopted phragmotic behaviour inside it. In both agar models and tree-frogs, total water evaporation increased with body size, but relative water loss was higher in smaller individuals. The presence of nail polish on agar models barely reduced water loss, suggesting that cranial skin co-ossification has a small role in water economy. Although both models and tree-frogs evaporated about 90% more water when exposed than when phragmotic, tree-frogs evaporated about 50% less water than agar models at any test condition. We conclude that reduced skin permeability, phragmotic behaviour and a keen capacity to identify humid crevices, explain the success of this species in a semi-arid habitat.

The fatty acid compositions of yolk lipids of eggs collected in the wild from five species of ducks (Anatidae) showing a range of dietary preferences, the king eider Somateria spectabilis, the lesser scaup Aythya affinis, the mallard Anas platyrhynchos, the green-winged teal Anas crecca and the gadwall Anas streperi, are reported. For all five species, the fatty acid profiles conformed to a similar pattern, characterized by relatively balanced proportions (w/w) of arachidonic (6.7–9.1%) and docosahexaenoic (5.9–7.0%) acids in yolk phospholipid. This contrasts markedly with the yolk phospholipid of current commercially-reared ducks where the proportion of arachidonic acid can be 10 times greater than that of docosahexaenoic acid. It was most notable that the similarities in yolk fatty acid profiles among the different species of wild ducks were achieved despite the considerable interspecies variation in dietary modes. It seems that, in this instance, genetic factors deriving from a common phylogeny may be more important than dietary differences in determining the fatty acid composition of yolk.

From what is known about the discovery of the gerenuk Litocranius walleri, the type locality is here restricted to the vicinity of Chisimaio, Somalia. Two discrete subspecies can be recognized. The smaller L. w. walleri occurs in north-east Tanzania, Kenya, southern Somalia and southern Ethiopia. The larger L. w. sclateri is restricted to Djibouti, northern Somalia and adjacent parts of northern Ethiopia and is present in very few protected areas.

Living individuals of the bivalve ‘watering pot’ superfamily Clavagelloidea were collected from Withnell Bay, Burrup Peninsula, Dampier Archipelago, Western Australia. Details of the anatomy suggest that, in most respects, Brechites vaginiferus is a typical filter-feeding bivalve, albeit encased in a tube of its own secretion. The true shell is tiny (≈ 4 mm long) and surrounded by a ‘saddle’ of initially-secreted adult shell. To this is fused, by an internally produced layer of calcium carbonate, the adventitious tube which comprises a single layer, confirming that it is produced only once. Posteriorly, however, it can be added to internally as ‘plaited ruffles’ creating a multi-layered structure. The anterior watering pot comprises a perforated plate fringed by tubules, with a small pedal aperture. Brechites vaginiferus pumps interstitial water into the mantle cavity via the watering pot, at least principally, not out of it as previously thought. In this way, the animal is either tapping an interstitial source of accessory food, or aerating the anterior end of its burrow (or both). It has also been demonstrated, however, that pumping interstitial water into the mantle cavity via the pedal gape results in hydraulic pressures being built up that extend the siphons. The pedal disc pump, therefore, acts in this amyarian bivalve in the same way as the adductor muscles do in more typical species. The ctenidia collect suspended material in the usual way from seawater and from interstitial water: they do not, however, possess chemoautotrophic sulphur-oxidizing bacteria, and the species is thus not using sulphur as an energy source. Pedal gape feeding is considered to be the ancestral condition not only in the earliest anomalodesmatans, e.g. the Pholadomyidae, but also the autobranchs in general. This has been refined in the Clavagelloidea to create the unique form of the adventitious tube, its watering pot and a wholly surprising lifestyle. Tube form in B. vaginiferus varies in relation to habitat occupied. Its major habitat on Withnell Bay, however, is the riffles of a high-salinity stream draining down the mangrove-fringed shore from the semi-arid land behind. Although much more is now known about B. vaginiferus and ‘watering pot’ shells, no pre-tube juvenile is known and awaits discovery to confirm hypothesized life-history details.