bluuebunny/crossref_metadata_2025 huggingface dataset:
Body size of male Atlantic walruses (Odobenus rosmarus rosmarus) from Svalbard
Authors: Whg Ø. , Gjertz I.
Published: May 2009

Morphometric data are given for 41 adult male Atlantic walruses (Odobenus rosmarus rosmarus) immobilized at Svalbard. Total body weight ranged from 960 to 1450 kg. Standard body length ranged from 258 to 380 cm, while curvilinear tusk length ranged from 17 to 65 cm. Immobilized animals were selected for their large size. The sample is therefore biased towards larger animals. Based on regression equations developed for walruses caught in Greenland, the weights of Svalbard walruses were estimated from standard body length and axillary girth. Estimated weights ranged from 632 to 1883 kg. The present data suggest that Atlantic walruses at Svalbard can attain the same body size as Pacific (O. r. divergens) and Laptev walruses (O. r. laptevi).
Temperature and the tropical tortoise Kinixys spekii: tests of thermoregulation
Authors: Hailey A. , Coulson I. M.
Published: May 2009

The mean body temperature (Tb) of active Kinixys spekii did not vary with sex or type of activity, or between hot days (maximum ambient temperature Ta > 29°C) and cool days. On hot days, Tb increased rapidly in the morning, and was constant during the late afternoon after midday inactivity. On cool days, Tb increased more slowly in the morning, and decreased during the afternoon. The slopes of Tb on Ta overall, and on hot days, were close to one, suggesting that tortoises were thermoconformers; the slope was greater than one on cool days. In a second test of thermoregulation, Tbs were compared with temperatures of null models (Tm). Tortoises were clearly thermoregulators compared to ‘active‐all‐day’ models. ‘Activity‐time’ models had Tm more similar to Tb. Nevertheless, detailed comparison showed that tortoises were thermoregulating in the late morning, and that this was by choice of microenvironment, rather than ceasing activity when Tb reached a high level. These results are discussed in relation to E, a measure of the effectiveness of thermoregulation based on comparison of Tb and Tm with the set point range (Tset) selected in a thermal gradient. A set of three indices, which separate the variability of Tb, the difference between Tb and Tm, and between Tb and Tset, is suggested as a more generally applicable summary of thermoregulation in ectotherms.
Activity patterns and resource use by sheep and red deer grazing across a grass/heather boundary
Authors: Hester A. J. , Mitchell F. J. G. , Gordon I. J. , Baillie G. J.
Published: May 2009

Diet selection and activities of sheep and red deer grazing alone and together across a grass (primarily Lolium perenne/Agrostis capillaris) and heather (Calluna vulgaris) boundary, between July and October, are described.

Throughout the experiment, both animal species had a much higher proportion of grass than heather in their diet. Time spent grazing on each type of vegetation was similarly greater on grass, and the bite rates of the animals were also more rapid on the grass than on the heather.

Red deer spent more time grazing per 24 hours than did sheep, with sheep grazing less during darkness hours than red deer. Total grazing time of both species did not decrease with decreasing daylength from July to October.

There were no consistent differences in the diurnal patterns of activity of sheep and red deer, with both species showing 2‐3 large grazing peaks per day.

There were no consistent effects of mixing sheep and deer on their grazing behaviour and diet composition.
Distribution and population densities of seven species of bat in northern England
Authors: Jones K. E. , Altringham J. D. , Deaton R.
Published: May 2009

Distribution and minimum population densities for seven UK bat species known to be resident in northern England were calculated in an area covering 2500 km2. The species present were pipistrelle (Pipistrellus pipistrellus), brown long‐eared (Plecotus auritus), Daubenton's (Myotis daubentonii), whiskered (Myotis mystacinus), Natterer's (Myotis nattereri), noctule (Nyctalus noctula) and Brandt's (Myotis brandtii). Data were collected primarily from counts at summer roosts over the period 1983 to 1990. A total of 310 bat roosts were discovered within the study area. Of the 256 roosts at which the species present was identified, the majority, 127 (49.6%) were P. pipistrellus, with a mean maternity roost size of 69.6 bats. A minimum population density of 12.6 batskm−2 was estimated for P. pipistrellus, based on summer (maternity) roosts. The minimum population density estimate was higher than previous studies in northern England but substantially lower than those reported in Scotland (18.2 bats km‐−2). The combined density of M. mystacinus, M. brandtii, and P. pipistrellus, which have similar foraging styles (15.8 bats km−2), is comparable to Scottish P. pipistrellus densities. The density of M. duubentonii was also lower than in Scotland, although the density of P. auritus was comparable. The majority of summer roosts for all species were found in buildings, except N. noctula and M. duubentonii which used bridges/tunnels or trees.
The diet of the mountain hare (Lepus timidus hibernicus) on coastal grassland
Authors: Wolfe A. , Whelan J. , Hayden T. J.
Published: May 2009

Across most of their range in Europe, mountain hares are usually restricted to upland areas with poor food quality. In these areas they generally feed on browse species such as heather or twigs and barks of trees. On lowland areas in Europe, with better food quality, the mountain hare is replaced by the brown hare (Lepus europaeus) which feeds predominantly on greasses. This khas led some authors to conclude that mountain hares are primarily adapted for browsing. In the absence of brown hares in Ireland, mountain hares are found on a wide variety of habitats including grassland. On grassland, their diet consists almost exclusively of grasses, up to 94% of their annual diet, which is more than has been reported for brown hares on similar habitat. Based on this evidence, and other work, it is proposed that the mountain hare in primarily a grazing animal and competitive exclusion by brown hares may underlie much of their present distribution in Europe.
Morphology of the subdermal connective tissue sheath of dolphins: a new fibre‐wound, thin‐walled, pressurized cylinder model for swimming vertebrates
Authors: Pabst D. Ann
Published: May 2009

The subdermal connective tissue sheath (SDS) of dolphins is a fibre‐reinforced membrane connected to other locomotor tissues, including blubber, axial muscles and tendons, and vertebral column. The complicated connections between the SDS and other locomotor tissues suggest that the SDS acts as a peripheral skeletal element for the axial locomotor muscles and as an anchor for a de novo dermal appendage, the dorsal fin. The morphology of the SDS suggests that the dolphin can be modelled as a fibre‐wound, thin‐walled, pressurized cylinder. Existing cylinder models predict that the SDS functions to resist torsional forces, prevent aneurysms, and limit wrinkling when the dolphin bends in locomotion. I present a new functional model that more accurately represents the morphology of the dolphin cylinder wrapped by the SDS. The new model predicts that the SDS: (1) acts as a retinaculum for the terminal tendons of the axial locomotor muscles; and (2) plays a role in maintaining the laterally flattened cross‐sectional shape of the caudal peduncle. The model is based on external morphological features of dolphins shared by other steady swimming aquatic vertebrates, such as carangiform and thunniform fishes. These features, which include a streamlined body shape and narrow necking of the caudal peduncle have been identified as adaptions to reduce drag. The new model offers insight into some of the structural features of the body wall required to maintain the hydrodynamicallytuned, external morphology of steady‐swimming vertebrates.
Phenotypic plasticity, cellular dynamics, and epithelial turnover of the intestine of Japanese quail (Coturnix coturnix japonica)
Authors: Starck J. Matthias
Published: May 2009

This paper discusses phenotypic plasticity of the avian intestine and presents data about the dynamics and mechanisms accounting for size variation of the avian intestine. Gut lengths of 56 bird species were compared for interspecific and intraspecific coefficients of variation. Intraspecific gut length variation relates to seasonal changes in quality and composition of food in some species. Such phenotypic plasticity is thought to adjust gut structure and function to seasonal differences in nutrition and to maintain optimized gut function under differing feeding regimes. Morphometry at five segments along the intestine provided basic measurements of the quail intestine. Whereas the duodenum can be separated from the rest of the intestine in almost all parameters, the small intestine, rectum, and caeca are rather uniform. Changes of circumference and length of the gut segments account for the major portion of size changes of the resorptive surface. BrdU/3H‐TdR double labelling experiments were performed to study the dynamics of cellular turnover of the intestine. The experiments revealed a constant S‐phase length of 6.5 hours along the intestine. The turnover time of the mucosa epithelium ranges between 9 and 17 days, depending on the circumference of the gut segment. Such a turnover time permits reconstruction of the intestine in short periods and its adjustment to seasonal differences in composition and quality of food. The study revealed significant differences between cell proliferation activity at day and at night. Animals labelled at night had almost twice the labelling index of those labelled during the day. These results were consistent in other tissues (liver, muscle, connective tissue, glandular stomach). Because high night‐time proliferation activity coincides with low antigen levels and high free radical scavenger concentration (e.g. melatonin),it is suggested that the circadian patterns in labelling index represent a fine tuning of DNA‐replication activity to ‘safer’periods of day.
Variation in cranial form and sexual dimorphism among five European populations of the otter Lutra lutra
Authors: Lynch J. M. , Conroy J. W. H. , Kitchener A. C. , Jefferies D. J. , Hayden T. J.
Published: May 2009

Craniometric variation between otters Lutra lutra (L.) from Ireland, Scotland, Shetland, Norway, and Czechoslovakia was examined using multivariate statistical analyses. Significant sexual dimorphism in cranial size and shape occurred in all samples, although the degree of dimorphism varied between samples, with the Irish sample exhibiting the most. Morphological differences were also observed across samples. Three groups were observed; Irish, Scottish, (Mainland and Shetland), and Mainland European, though within the two composite groups the samples were still differentiable. There was a good agreement between the patterns of variation between male and female samples, but morphological differentiation was not significantly correlated with geographic separation. These results are discussed in the light of our current knowledge of the ecology of the species in Europe. It is argued that, while there is morphological evidence for subspecific status of the Irish otter (as L. l. roensis), further investigations of morphological and genetic variation across Eurasia are clearly required.
Age and growth of the soldier, Sebastes capensis (Pisces: Scorpaenidae) at Tristan da Cunha and Gough Island, South Atlantic Ocean
Authors: Andrew T. G. , Hecht T.
Published: May 2009

Age and growth in the scorpaenid Sebastes capensis was studied at Tristan da Cunha and Gough Island using otoliths. The growth rate of specimens collected at Gough Island was almost twice that of specimens collected at Tristan da Cunha. The largest specimen from Tristan was aged at 18 years while similar‐sized fish from Gough were only 11 years old. Because the populations at the two localities were not considered to be genetically isolated from one another, it was hypothesized that the difference in the growth rate and longevity was related to site‐specific environmental conditions. Inshore sea temperatures were, on average. 3°C higher at Tristan than at Gough throughout the year. It is concluded that this temperature difference may affect growth rate indirectly through regulating diet and metabolic activity in S. capensis. Changes in reproductive strategy related to the level of environmental predictability at the two localities may also affect growth rate in this species.
Ploughing behaviour of Babyrousa babyrussa, (Suidae, Mammalia) suggests a scent‐marking function
Authors: Leus K. , Bland K. P. , Dhondt A. A. , Macdonald A. A.
Published: May 2009

A unique form of behaviour,‘ploughing behaviour’, was studied in experiments carried out on 13 babirusa, three adult males, two sub‐adult males, five adult females and three sub‐adult females. Ploughing behaviour was observed when individual animals were introduced singly into empty sand‐filled enclosures at Antwerp Zoo. The animal put its snout into the sand to such a depth that the sand was just in front of its eyes, whereupon it knelt and slid forward on to its chest. The head and chest of the animal were thereby pushed forward through the sand and canted left and right alternately. Ploughing behaviour was almost exclusively performed by adult males, the periods of longest duration being seen either in the enclosure of another male or in a freshly cleaned enclosure. The copious amounts of saliva which were produced as foam at the sides of the mouth prior to ploughing had disappeared by the end of this activity. This supports the idea that ploughing by the babirusa has a scent‐marking function. The adult female did not show ploughing behaviour.
Morphology and evolution of two takahe: flightless rails of New Zealand
Authors: Trewick S. A.
Published: May 2009

Two forms of a large and flightless rail (takahe) belonging to the genus Porphyrio and endemic to New Zealand have been described, although their taxonomy has been repeatedly questioned. Analyses of osteometric data from modern and Quaternary fossil material show such a degree of allometric distinctiveness that it is considered that the two forms are, indeed, different species as originally described, Porphyrio mantelli (Owen), Porphyrio hochstetteri (Meyer). It is suggested that this degree and type of difference could have resulted from the two species arising independently from similar volant ancestors.
Ototyphlonemertes correae sp. nov. and a redescription of O. duplex (Nemertea: Monostilifera: Ototyphlonemertidae), with a phylogenetic consideration of the genus
Authors: Envall Mats
Published: May 2009

The species Ototyphlonemertes correaesp. nov. and O. duplex Bürger, 1895 (Ototyphlonemertidae) are described. The new species possesses a smooth stylet, oligogranular statolith and nephridia. Phylogenetic relationships are reconstructed for 21 Ototyphlonemertes species, based on an analysis of 18 morphological characters, totalling 43 character states. The most informative characters are stylet structure, basis shape, statolith shape and nephridia. Based on the phylogeny, the subgenus Otohelicophora (Greek, helicophora meaning the spiral carriers) is separated, which is defined with reference to the synapomorphy ‘spiral stylet’.
Ecogeographic variation in body size and shape of Cape sparrows (Passer melanurus) in southern Africa
Authors: Slotow R. , Goodfriend W.
Published: May 2009

Canonical discriminant analyses were used to assess whether four populations of Cape sparrows varied in body size and shape according to predictions from Bergmann's Rule. In accordance with Bergmann's Rule, birds from two hot, arid Namib desert sites (Namib 1 and Namib 2) were smaller than birds from two cool, mesic Transvaal sites. If heat dissipation through extremities (tarsi) is important to reduce water lost from evaporative cooling, birds under hot conditions in dry environments (Namib 2) should have longer tarsi than those in more humid hot environments (Namib 1). Contrary to this, males at Namib 2 had relatively longer wings hut shorter tarsi than at Namib 1, and female relative tarsus length did not vary between desert sites
Errors associated with otter Lutra lutra faecal analysis. II. Estimating prey size distribution from bones recovered in spraints
Authors: Carss D. N. , Elston D. A.
Published: May 2009

New methods of estimating the size of salmonids Salmo spp. and eels Anguilla anguilla consumed by otters Lutra lutra are presented, based on feeding trials involving captive, tame otters. These methods involve modelling the size‐related differential recovery of key fish bones recovered in faeces (spraints) and avoid two sources of errors that may have occurred using previous techniques which relied solely on a series of correlations between fish length and the length of individual vertebrae. Sources of errors avoided are: (a) that vertebrae recovered in spraints could not always be assigned to the correct correlation equation for mean, maximum, or minimumsized bones; and (b) that the number of fish represented in a spraint was assumed to be one, in the case of similarly‐sized vertebrae, and two in the case of bones varying considerably in size. We tested the use of salmonid atlas vertebrae to determine the largest minimal numbers estimate, the length frequency distribution of salmonids consumed, and to estimate the proportions of trout and salmon in the diet. Eels do not contain an atlas which is resistant to digestion and so equivalent estimates of the minimum numbers of fish represented in spraints are not possible. A model was therefore developed to estimate the distribution of lengths of fish consumed from the lengths of thoracic vertebrae recovered in the spraints using a series of equations. For each type of prey (salmonids or eels), the proportions of identifiable bones recorded in spraints were related to the original size of ingested fish. Such models greatly enhance the value of otter spraint analyses, particularly for size‐selection studies.
Cellular substructures in the optic tectum of Antarctic and temperate fish
Authors: Kourtje K.‐H. , Aich B. , Lips K. , Rahmann H.
Published: May 2009

The brain of Antarctic fish of the perciform suborder Notothenioidea was analysed with lightand electronmicroscopical methods. The overall organization and ultrastructure of the optic tectum is very similar to that of fish from temperate climates. However, unusual structures were observed in neurons and glial cells, sometimes in high frequencies. The structures are ovoid or elongated, about 200‐600 nm in diameter and surrounded by two layers of membranes in a uniform distance of about 30 nm. The enclosed inter‐membrane space is similar to extracellular space, both in size and in cytochemical calcium precipitation, while the interior of the structures resembles cytoplasm. These structures are sometimes connected to neuronal processes, so that they seem to originate by a sort of budding process, but most of them are isolated as can be concluded from thick sections of up to 800 nm thickness, analysed with energy‐filtering transmission electron microscopy (EFTEM). These unusual objects are present in high abundance in members of the white‐blooded Antarctic fish family Channichthyidae. These so‐called icefish lack haemoglobin and exhibit the highest degree of cold adaptation. The red‐blooded notothenoid fish had smaller amounts of these structures and they were observed even in fish from temperate climates (trout, carp, cichlid fish). In fish from temperate climates the unusual substructures were more abundant during adaptation to cold water temperatures (winter) than to warm conditions (summer). Therefore, the findings may indicate a general phenomenon of cold adaptation with unusual interactions of neurons and glial cells, but the precise function is not yet understood.
Geographical variation in the genusDendrelaphis(Serpentes: Colubridae) within the islands of south‐eastern Indonesia
Authors: How R. A. , Schmitt L. H. , Maharadatunkamsi
Published: May 2009

The south‐eastern islands of Indonesia between Bali in the west and Timor in the east define a region that is at the interface of the Asian and Australasian biogeographic regions. Three subspecies of the colubrid snakeDendrelaphis pictushave previously been recognized from the region:Dendrelaphis pictus pictus(Bali and Lombok);D. p. inornatus(Sumba to Timor); andD. p. intermedius(Sumbawa to Alor). A re‐examination ofDendrelaphis pictusin this region uses multivariate statistics to examine the geographic variation in head‐shield and body measurements within the species. The findings re‐interpret the taxonomy, indicating thatD. pictusfrom Bali and Lombok are specifically different fromD. inornatuson the remaining islands on the Banda Arc. The populations ofD. inornatuson the islands of Sumbawa, Sumba, Sawu, Flores, and Lembata are subspecifically different from those on Roti, Semau, Timor, Alor, and Wetar.

Several head‐shield measures are strongly correlated with longitude withinD. inornatus, suggesting environmentally triggered selection gradients. However, for many variables, the two subspecies differ significantly in the direction of the trends which suggests the subspecies respond differently to these environmental gradients. There is evidence thatDendrelaphisindividuals may be transported through the islands by anthropogenic agencies.
Locomotor behaviour in Plio‐Pleistocene sabre‐tooth cats: a biomechanical analysis
Authors: Anyonge William
Published: May 2009

The locomotor behaviour of some large extinct carnivores, including several species of Plio‐Pleistocene sabre‐tooth cats, is here reconstructed, based on a comparison of the cross‐sectional geometric properties and linear dimensions of their femora and humeri with those of large modern carnivores. The long bones are modelled as simple beams, thereby allowing the use of basic beam theory in assessing relevant functional parameters such as second moments of area of the diaphyses when subjected to compressive and bending stresses. Three Pleistocene carnivores, Smilodon fatalis, Homotherium serum, and Panthera atrox seem to have had ecological and functional equivalents among the late Miocene‐Early Pliocene genera, Barbourofelis, Machairodus, and Nimravides, respectively. Barbourofelis and Smilodon were ‘cat‐like’in dental morphology but some structural characteristics of their limb bones had ‘bear‐like’affinities. Machairodus and Homotherium were cursorial, whereas Nimravides and P. atrox display the limb morphology of true ambush predators. Various aspects of the postcranial skeleton of some of these extinct carnivores suggest that they may have employed locomotory gaits that lack modern analogs.
Allometry of the leg muscles of birds
Authors: Bennett M. B.
Published: May 2009

The musculoskeletal components of the hindlimbs of 20 species of birds, considered non‐runners, were examined. Allometry was used to compare these data with previously published information on the limbs of running birds. In non‐runners the digital flexor muscle and tendon areas scaled approximately isometrically, in contrast to running birds where tendon areas had a lower exponent. Non‐running birds had muscle fibre areas approximately half that of runners of equal mass. In both groups, the muscle:tendon area ratio for m. gastrocnemius increased as M0.13, suggesting factors other than elastic energy storage are important. Runners exhibited relatively longer tibiotarsi and tarsometatarsi and shorter toes. With very few exceptions, the linear dimensions of bones, tendon cross‐sectional areas, and muscle masses and fibre areas in the legs of the non‐running birds scaled closely according to the requirements for geometric similarity, but the confidence limits are often wide. Deviations from geometric similarity in birds reflect differences in locomotor behaviours and abilities.
The influence of size differntial on agonistic behaviour in the freshwater crayfish, Cherax cuspidatus (Decapoda: Parastacidae)
Authors: Pavey C. R. , Fielder D. R.
Published: May 2009

The agonistic behaviour of juvenile pairs of intermoult freshwater crayfish Cherax cuspidatus, interacting over space in experimental containers, was examined. The study investigated the effects of differences in Resource Holding Potential (RHP) on social rank, patterns of interaction initiation, and the importance of fighting during encounters between pairs of crayfish. Crayfish were paired with unfamiliar opponents at size classes of 1 : 1, 1 : 0.9, 1 : 0.8, I : 0.7 and 1 : 0.6 using standard carapace length as the RHP index.

Larger animals were dominant during significantly more than 50% of replicates at all size classes. Larger animals were dominant at all size ratios lower than 1 : 0.89. Seven smaller animals were dominant at size ratios between 1 : 0.89 and 1 : 0.99. The dominance of smaller animals could not be explained on the basis of morphological measures or age. The influence of prior experience as dominants or subordinates on the behaviour of contestants during these encounters appeared the most likely explanation.

Carapace length, body length, and weight were equally reliable RHP indices. Age, number of injuries, and sex were not reliable RHP indices.

The probability of initiating the first agonistic bout was independent of relative size for three of the five size classes. Larger initiators of the first bout invariably were successful, while smaller initiators rarely won. The winner of the first bout was the overall dominant during significantly more than 50% of replicates at each size class. The dominant individuals initiated the majority of bouts at all size classes, including the seven replicates where the smaller crayfish was dominant.

Fighting (fight time, fight frequency, average bout length), a high intensity behaviour, was an important component of contests at the 1 : 1, 1 : 0.9, and 1 : 0.8 size classes. The significance of fighting was greatly reduced at the 1 :0.7 and 1 : 0.6 classes, indicating that fighting was correlated with the relative size of opponents.
Physical growth of northern fur seals (Callorhinus ursinus): seasonal fluctuations and migratory influences
Authors: Trites A. W. , Bigg M. A.
Published: May 2009

Growth curves are described for males, pregnant females, and non‐pregnant females using morphometric measurements collected from over 18000 northern fur seals (Callorhinus ursinus) shot at sea between California and the Bering Sea from 1958 to 1974. Seals of all ages experience seasonal increases and decreases in body mass and length. Seasonal fluctuations of body length may be an artefact of mass displacement caused by seasonal changes in mass. Rapid growth and gain in mass occur during a brief one to three month period as the population migrates northward through the coastal waters of northern British Columbia and Alaska on their way to the Pribilof Islands. Body mass of females and immature males is gradually lost while fasting on land and wintering along the coasts of Washington, Oregon, and California. Pregnant females are both heavier and longer than non‐pregnant females of the same age. Body mass in pregnant females levels off with age in contrast with the increasing mass of non‐pregnant females. Growth of northern fur seals does not appear to stop at an upper asymptote, but continues throughout their life spans.
Studies of the behaviour of Artioposhia triangulata (Platyhelminthes; Tricladida), a predator of earthworms
Authors: Lillico S. , Cosens D. , Gibson P.
Published: May 2009

A significant negative correlation between the numbers of earthworms and the flatworm was demonstrated in fromalin‐sampled lawns. Their distributions, recorded by a transect from a shrub border where the flatworm is suspected to have been introduced, indicated that predation may lead to earthworm extinction. Two different vermarium designs demonstrated a gradation of earthworm vulmerability to the flatworm due to depth within the soil and burrow width rather than perference for specific earthworm species. A strong correlation between the level of earth worm predation and flatworm movement implied active hunting. A predation rate was found to be 0.67 of an earthworm per flatworm per week with a metabolic conversion rate of 10%.
Mechanical properties of the peristomial membrane of the cidaroid sea‐urchin Stylocidaris affinis
Authors: Wilkie I. C. , Carnevali M. D. Candia , Andrietti F.
Published: May 2009

The peristomial membrane (PM) is the area of flexible body wall which surrounds the mouth of regular sea‐urchins. In cidaroid sea‐urchins, like Stylocidaris. affnis (Phil.), it contains an extensive endoskeleton of overlapping plates. This paper describes the basic mechanical properties of the PM of S. affinis and compares them with those of the PM of the previously studied echinacean euechinoid Paracentrotus lividus. When subjected to vertical deformation, the PM of S. affinis generates J‐shaped tension‐deformation curves with an inflexion point at a deformation corresponding to about 3% of the perignathic girdle diameter. It is considerably stiffer than the P. lividus PM and, unlike the latter, it shows asymmetrical properties, i.e. greater resistance to aboral flexion (retraction) than to oral flexion (protraction). In interambulacral regions the junction between the PM endoskeleton and test of S. affinis takes the form of a wide ligament‐filled gap which acts as a compliant hinge. In marked contrast to the echinacean PM, that of S. affinis provides little evidence for the presence of mutable collagenous tissue (MCT). The cidaroid PM is interpreted as a design which maximizes mechanical defence whilst retaining the capacity for some flexibility. A possible correlation between the lantern systems and feeding habits of sea‐urchins is discussed.
Reproductive patterns of a biologically invasive species: the brown tree snake (Boiga irregularis) in eastern Australia
Authors: Whittier J. M. , Limpus D.
Published: May 2009

Boiga irregularis, a snake native to Australasia, is a biologically invasive species that has become established on Guam and threatens to spread to other Pacific Islands. In eastern Queensland, we found that the snake breeds seasonally and gonadal development of males and females is temporally dissociated in time. Although the period of mating in this snake is not known, these data suggest that obligatory sperm storage in the reproductive tract occurs during the reproductive cycle. Such sperm storage may partially explain the success of this species as a biological invader.
The endocrine basis of the reproductive cycle in the king penguin (Aptenodytes patagonicus)
Authors: Jouventin P. , Mauget R.
Published: May 2009

What is the breeding frequency of the king penguin? More than 30 years of study and five major investigations, did not answer this question owing to the length (14 months) and the spreading (four months of laying) of reproductive events.

Following intensively during three consecutive years nearly 1000 tagged birds in a small colony, we obtained the individual history of a large part of the population. To these demographic and phenological studies, we have associated an endocrinological study validating blood samples and experiments in another colony.

The success or failure of a breeding cycle determines the timing of the subsequent breeding attempt. At Crozet Islands, the king penguin can rear one chick every two years at best: a successful breeding is followed by unsuccessful late breeding (or by non‐breeding). So a large part of the population displays an annual periodicity of breeding attempts but with low individual breeding success.

The restarting of the reproductive cycle appears basically to be annual, the pituitary responding to the photoperiod. Steroid patterns present classical variations of level according to the reproductive stage. Prolactin (PRL) and luteinizing hormone (LH) are antagonists but, in this species, PRL remains high without external stimulation. To relay after failure in the field. we have experimentally to break down endogenous PRL. So, we have demonstrated that PRL has a key role in the reproductive cycle.

Paradoxically, the king penguin is an irregular breeder, quasi‐biennial, although physiologically an annual breeder. In winter, there is not enough food at sea to rear the chick and during four months, the chick fasts. So a successful breeding cycle, which can be shortened to only nine months in captivity, is extended to more than a year for ecological reasons.
Physiological adaptation to aridity in the bushveld gerbil, Tatera leucogaster
Authors: Webb P. I. , Skinner J. D.
Published: May 2009

Oxygen consumption, rectal temperature, thermal conductance, and evaporative water loss (EWL) were determined in resting captive Tatera leucogaster at ambient temperatures of between 14 and 38 °C. Basal metabolic rate (BMR) was 0.86 ml O2. min−1 (S.D.=0.15, n= 6), 45% of that expected for a rodent of the same body mass (106.2 g). Minimum wet thermal conductance was 0.21 ml O2. min−1, °C−1 (S.D. = 0.01, n= 6), 113% of that expected for a mammal of the same body mass. Wet thermal conductance increased exponentially at temperatures greater than 32 °C. Mean rectal temperature was 35.3 °C below 35 °C (S.D. = 0.5, n= 6) and 39.3 (S.D. = 0.6, n= 5) at 38 °C. Mean resting EWL was 1.43 mg. min−1 (S.D. = 0.14, n= 6) between 15 and 32 °C and increased dramatically at temperatures above 32 °C. Combining our data with data from the literature suggests that gerbils (Family Muridae; subfamily Gerbillinae) have, on average, low BMR and average minimum wet thermal conductance when compared to other rodents and other mammals, respectively, of the same body mass. Similarly, rodents (including gerbils) from arid habitats have, on average, lower rates of EWL when at rest below thermoneutrality than do other rodents of the same body mass from mesic habitats.
Insect rope‐walkers: kinematics of walking on thin rods in a bug, Graphosoma italicum (Heteroptera, Pentatomidae)
Authors: Frantsevich L. , Mokrushov P. , Shumakova I. , Gorb S.
Published: May 2009

Leg positions during walking on a plane and on thin rods were recorded by photography, videorecording, and videokymography. Joint angles were reconstructed from the tibia‐ending position, using a 3‐D model of the body. Participation of leg joints in propulsion was analysed by calculating the partial derivatives of tibia end‐point position on different joint angles. Adjustment to walking with a narrow ground base is achieved by additional femur depression and flexion of the tibia in the stance phase. In the swing phase, the leg is raised by the same amount as when walking on a plane, but not to the same superior position, as on a plane. The contribution of the subcoxal joint to body propulsion is 64‐94% in fore‐and middle legs and 22‐49% in hind legs. The oblique alignment of the coxal pivot within the thorax helps maintain a long stride for variable ground bases. In Graphosoma, it is close to the optimal position: according to several criteria, the angle between the coxal axis and the body vertical shall be arctan π/2, or ∼ 57.5°.
Branch‐fidelity in the tree crab Sesarma leptosoma (Decapoda, Grapsidae)
Authors: Cannicci S. , Ruwa R. K. , Ritossa S. , Vannini M.
Published: May 2009

Sesarma lepzosoma is the only species of crab inhabiting the mangrove swamps of East Africa which can climb to the top of tall mature trees, where it feeds on fresh leaves. Twice daily, in the morning and evening, this crab performs mass migrations towards the canopy and spends about three hours on the tree‐tops. At dusk it descends to spend the night among the aerial roots of the tree. Two observation stations were built on a Rhizophora mucronata tree, up to 13 metres above ground level, to observe and record the feeding and spatial aspects of the behaviour of this species during its time in the canopy. Observations on the daily migrations of marked specimens showed that the crabs are faithful to a well‐defined feeding site; moreover, the migration paths of the marked specimens were exceptionally constant over the whole of the two‐month study period. S. leptosoma was observed to feed on mature fresh leaves by scraping the lower surface of the leaf with its chelae. It was also found to spend most of its time on leaf‐buds in a particular stage of development. Water which accumulates among the scales covering these buds represents an important water supply for these crabs, which they prestmably use to reduce physiological stress due to water loss. Feeding‐site fidelity in S. leptosoma seems to be related more to the chance of finding suitable leaf‐buds, which are relatively rare and patchily distributed, than finding leaves, which are abundant and uniformly distributed all over the canopy.
The morphological development of the locomotor and cardiac muscles of the migratory barnacle goose (Branta Leucopsis)
Authors: Bishop C. M. , Butler P. J. , El Haj A. J. , Egginton S. , Loonen M. J. J. E.
Published: May 2009

The masses of the locomotor and acardiac muscles of wild barncale goose gollings, from migratory population, were examined systematically during development and their values compared to those of pre‐migratory geese. Pre‐flight development was typified by approximately linear increases of body, leg, and heart ventricular mass with respect to age. Flight muscle showed an exponential increase in mass. Pectoralis muscle mass was 14.2 ± 0.3% of body mass (1297 ± 73g, n=7) in early flying goslings compared to 16.6 ± 0.3% of body mass (2318 ± 109g, n=8) in pre‐migratory geese. Post‐flight development was typified by stasis of leg muscle mass but hypertrophy of Ventricular and pectoralis muscle mass in proportion to body mass. Ventricular mass relative to body mass showed the lowest values at 5 weeks of age (0.62 ± 0.01%) with peak values at 1 week of age (10.4 ± 0.04%). The latter may be associated with both requirements of thermoregualation in these precocial, arctic breeding geese and the need to forage approximately 24 hours post‐hatch. Peak values for leg muscle mass, relative to body mass, were found at 3 weeks of age (12.7 ± 0.36%), with lowest values in the pre‐migratory geese (6.7 ± 0.21%), while peak values for pectoralis muscle mass were expressed in the premigratory geese with lowest values at 1 week of age (0.94 ± 0.07%). Ventricular mass was proportional to leg muscle mass up to 5 weeks of age (Mv= 0.38Mt0.68, r2=0.95), but subsequent increase in ventricular mass was proportional to pectoralis muscle mass (Mv= 0.25Mp0.73, r2= 0.81).
Thermoregulation in two population of the Matabeleland mole‐rat (Cryptomys hottentotus nimrodi) and remarks on the general thermoregulatory trends within the genus Cryptomys (Rodentia: Bathyergidae)
Authors: Bennett N. C. , Cotterill F. P. D. , Spinks A. C.
Published: May 2009

The social Matabeleland mole‐rat Cryptomys hottentotus nimrodi occurs in both the high‐and lowveld of Zimbabwe. The population in the highveld has a mean (± S. D.) resting metabolic rate (RMR) when acclimated for three months in the laboratory of 0.83 ± 0.04cm3 O2 g‐l h‐l (n=12) within the thermoneutral zone (TNZ) of 31‐32°.

The body temperature (Tb) within the thermoneutral zone is low 34.4 ± 0.18 (n= 12) and remains stable at ambient temperatures (Ta s) from 25‐32°. Above 32°, Tb increases albeit slightly to 36.6 ± 1.46° (n= 12). The conductance is high 0.17 0.02cm3 O2 g‐1 h‐°‐1 (n= 24) at the lower limit of thermoneutrality. The mean RMR at 18° (the lowest Ta tested) was 2.29 ± 0.11 cm3 O2 g‐1 h‐1, which is 2.75 times that of the RMR in the TNZ.

The population in the lowveld has a mean (± S.D.) resting metabolic rate (RMR) when acclimated for three months in the laboratory of 0.95 ± 0.07 cm3 O2 g‐1 h‐1 (n= 12) within the themoneutral zone (TNZ) of 28‐30 °.

The body temperature within the thermoneutral zone is low 34.0 ± 0.23 (n= 12) and remains stable at Tas from 25‐30 °. Above 32 °, Tb increases, albeit slightly, to 37.8 ± 1.14 ° (n= 12).

The conductance is high 0.14 ± 0.09cm3 O2 g‐1 h‐1°‐1 (n= 24) at the lower limit of thermoneutrality. The mean RMR at 18 ° (the lowest Ta tested) was 1.96 ± 0.12cm3 O2 g‐1 h‐1, which is 2.0 times that of the RMR in the TNZ.

These thermoregulatory parameters are compared with published data on other species of Cryptomys from Southern and Central Africa.
Age and size structure of populations of small marbled newts (Triturus marmoratus pygmaeus) from Doñana National Park (SW Spain). A case of dwarfism among dwarfs
Authors: Diaz‐Paniagua C. , Mateo J. A. , Andreu A. C.
Published: May 2009

The body size of specimens of Triturus marmoratus pygmaeus from Doñana is the smallest recorded for this subspecies. Snout‐vent length averages 42.3 mm in males, and 43.9 mm in females. Mean body mass in males is 2.04 g and 2.29 g in females. The age of newts was estimated by means of skeletochronological methods. The maximum longevity recorded was 10 years in females and nine years in males, with one or two years being the age at maturity. As in other newts, body size is not a good predictor of age, since a wide range of body length was found within each age class. Growth in females was substantial in subsequent years, showing an overall positive tendency. However, males showed slight or even negative growth. Newts from Doñana are different from other nearby localities with similar climatic characteristics. This is mainly due to their short juvenile and terrestrial phase.
Reproductive seasonality in Kafue lechwe antelope
Authors: Nefdt Rory J. C.
Published: May 2009

Kafue lechwe antelope (Kobus leche kufuensis) inhabit a wetland area of the Kafue Flats in southern Zambia and have seasonal peaks in mating and calving. The construction of a hydroelectric scheme has recently altered the time of year when flooding starts, and there has been a corresponding change in peak mating and calving dates. In this study, Kafue lechwe mated mainly during the dry part of the year when grass quality and quantity was at its lowest and when water levels were increasing and thus inundating any potential food. As rising water levels corresponded with increases in numbers of oestrous females on leks (both before and after dam impoundment), and with increased mating rates in two other subspecies of lechwe (the black and red lechwe), floods appear to act as a proximate cue for the initiation of mating. Mating during rises in water levels results in most calving occurring seven months later (the gestation period) when the floodwaters are receding and exposing optimal forage, irrespective of the time of year, and this increases the survival of the lactating mothers and their calves.
The temporal ligaments and their bearing on cranial kinesis in lizards
Authors: Iordansky Nikolai N.
Published: May 2009

In the lateral temporal opening of the lacertilian skull there are three main types of ligaments: quadratojugal, jugomandibular, and quadratopostfrontal. The quadratojugal and ventral jugomandibular ligaments transmit the retraction force from the lower jaw to the rhinal unit of the maxillary segment. The dorsal jugomandibular ligament causes the coupled kinesis, that results in the protraction of the whole maxillary segment (in the amphikinetic skull with simple streptostyly) or in the protraction of the quadrate‐mandibular complex (in the hyperstreptostylic skull), when opening the mouth.
Phenology of migration and use of wintering sites by the increasing population of dark‐bellied brent geese Branta bernicla bernicla
Authors: Summers R. W. , Underhill L. G. , Howells R. J. , Vickery J. A. , Prycs‐Jones R. P.
Published: May 2009

During the recovery of the population of dark‐bellied brent geese Branta bernicla bernicla, traditional wintering sites in Britain have experienced increases in numbers and new sites have been colonized. Goose counts were used to describe the migration phenology and winter use of Scolt Head, north Norfolk (a traditional site) and the Burry Inlet, South Wales (a relatively new site) over the period of re‐colonization and colonization, respectively. During the 1950s, only a few hundred birds wintered at Scolt Head, and most stayed for only a short period. By the late 1980s/early 1990s, numbers had reached several thousands, their period of stay was longer and there was little variation between years in median arrival (28 October) and departure (11 March) dates. A similar process was observed during the entire colonization phase at the Burry Inlet; initially birds arrived late and departed early, but arrived progressively earlier and departed later as wintering numbers increased. The autumn arrival rates at both sites were slower than the spring departure rates. During years of good breeding productivity, those adults with young arrived slightly later in Norfolk than failed breeders and non‐breeders, and a higher proportion of young birds remained in spring after the main departure. However, the overall pattern of arrival and departure did not vary according to whether there had been a good or poor breeding season. Some adults of breeding age also remained until May. The effects of food depletion and use of novel feeding habitats in relation to migration phenology and winter use of sites are discussed.
A neglected life‐history trait: clutch‐size variance in snakes
Authors: Shine R. , Seigel R. A.
Published: May 2009

Most analyses of life‐history traits have focused on mean values rather than their associated variance. We review published and original data on snakes, including records gathered over many years on single populations, to examine patterns in clutch‐size variability in these animals. Within single populations, the coefficient of variation of clutch size did not vary significantly with maternal body size, or among years. The stability of clutch‐size variance through time is consistent with experimental studies showing no significant influence of food intake rates on this characteristic. Clutch‐size variances did not differ between viviparous and oviparous snakes, but were dependent upon allometric relationships involving maternal body size and the relationship between clutch size and body size. Clutch‐size variability was highest in species with relatively variable female sizes, and with a high rate of increase in clutch size with increasing body size. These two factors acted to magnify the extent of clutch‐size variability engendered by variability in maternal body sizes. The relationships among these variables were similar in the two squamate Suborders, but the larger body sizes and mean clutch sizes of snakes resulted in clutch‐size variances being higher in snakes than in lizards.
Growth in early life and relative body size among adult polar bears (Ursus maritimus)
Authors: Atkinson S. N. , Stirling I. , Ramsay M. A.
Published: May 2009

Data on the body length (cm) of polar bear (Ursus maritimus), collected as part of a long‐term ecological study in the Hudson Bay region of Canada, were examined to test the hypothesis that growth early in life influences adult body size. Data for 42 females and 30 males that were captured as two‐year‐olds (2.6‐2.9 years), after the period of maternal care, and later recaptured as adults were analysed. On average, females increased in length by 11.2% and males by 23.1 % between captures. Relative adult body length was significantly correlated with relative length as a two‐year‐old in females but not in males. Thus, body length attained by two‐year‐olds is a weaker determinant of adult body length in males than in females. We suggest that, in comparison with females, prolonged growth beyond the period of maternal care may predispose the growth and eventual adult body size of male offspring to a greater degree of environmentally mediated variation. Furthermore, while data on maternal investment strategies in polar bears are lacking, variation in the allocation of maternal resources to cubs, within and among litters, may have a limited impact on the eventual adult body size of any surviving male offspring.