bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil and burrow temperatures, and the resource characteristics of the social mole‐rat Cryptomys damarensis (Bathyergidae) in the Kalahari Desert
Authors: LOVEGROVE B. G. , KNIGHT‐ELOFF ANETTE
Published: March 2009

The diel temperatures of the soils and burrows of the Damara mole‐rat Cryptomys damarensis were measured during winter and summer in the Kalahari Gemsbok National Park, South Africa. Also, the subterranean resource characteristics of C. damarensis, such as food abundance, spatial dispersion patterns and quality, were measured. The mean temperatures of the primary burrows were 33.5 C and 18.8 C during summer and winter, respectively. These temperatures were higher and lower than the upper and lower limits of thermoneutrality of C. damarensis, respectively. Resource characteristics were found to be habitat‐specific. Where geophytes occurred in high densities, such as the bulbs of Dipcadi gracillimum (40–118 bulbs.m‐2), they were small (0.41–5.17 g), but represented a good quality diet. Where densities were low, such as for the tubers of Acanlhosicyos naudinianus (0.17‐0‐407 tubers.m‐2), they were considerably larger (670 g), but represented a poor quality diet. These patterns confirm a general trend with increasing aridity, of increased geophyte sizes and decreased geophyte densities. In the Bathyergidae, these trends are accompanied by increased sociality and decreased body sizes.
Anatomical and functional aspects of the nasal mucosal and ophthalmic retia of phocid seals
Authors: FOLKOW L. P. , BLIX A. S. , EIDE T. J.
Published: March 2009

The anatomy of the nasal conchae with their mucosal vasculature, as well as that of the ophthalmic retia mirabile of grey (Halichoerus grypus) and harp (Phoca groenlandica) seals were investigated by dissection, injection and histological techniques.

The highly convoluted nasal conchae had a surface area of approximately 25 cm2.kgw‐1, usually with an air space of less than 1.0 mm between the conchal lamellae. A longitudinally oriented, extensive conchal mucosal rete is supplied caudally by the sphenopalatine artery. A plexus of retial veins runs adjacent to, and in close contact with, the retial arteries. The venous plexus may be drained caudally, primarily by the sphenopalatine/descending palatine veins, and/or rostrally, by the dorsal nasal vein. Microscopical examination revealed that the arterial and venous retial vessels communicate mainly through capillaries, but some arterio‐venous anastomoses were detected in the alar fold region. The nasal conchae provide the means for efficient conservation of heat and water by nasal temporal counter‐current heat exchange. This is due to a thermal gradient, which will exist along the nasal mucosa, as long as the animal is breathing air colder than body temperature. We suggest that the blood usually runs in a counter‐current fashion in the conchal mucosal retia, whereby the temperature gradient along the mucosa may be maintained. Moreover, the steepness of this gradient may be altered by changes in nasal mucosal blood flow so as to control accurately the extent of respiratory heat and water loss. Both species possess a complex ophthalmic rete mirabile. Arterial supply to the rete is by the external ophthalmic artery, while venous drainage may occur by way of several anastomosing veins. The vascular arrangement suggests that counter‐current heat exchange may take place between arterial and venous blood. Such exchange would allow the temperature of the eye to be maintained at a lower level than that of the ophthalmic arterial blood and, hence, reduce heat loss from the large pinniped eyes.
The ontogeny of functional design: metamorphosis of feeding behaviour in the tiger salamander (Ambystoma tigrinum)
Authors: SHAFFER H. B. , LAUDER G. V.
Published: March 2009

The ontogeny of feeding behaviour was studied quantitatively in the tiger salamander, Ambystoma tigrinum, to elucidate the relative importance of morphological and environmental changes on form and function. High‐speed films of prey capture provided data for a frame‐by‐frame analysis of seven kinematic parameters of feeding behaviour. By comparing underwater feeding of larval and metamorphosed individuals, the effect of morphological changes occurring at metamorphosis on the feeding kinematic pattern was determined. By comparing metamorphosed animals feeding in the water and on land, changes in feeding kinematics associated with the environmental transition (and thus the differing physical properties of water and air) were determined. Both univariate and multivariate analyses failed to demonstrate any differences between larval and metamorphosed aquatic feedings for seven kinematic variables. However, when individuals feed on land, a radical shift in hyoid kinematics was observed. In addition, multivariate analysis showed that terrestrial feedings differed from aquatic feedings in having longer duration head movements. The lack of a kinematic difference between larval and metamorphosed individuals feeding in the water indicates that the morphological changes occurring at metamorphosis do not impose any obligatory kinematic consequences. Rather, metamorphosed Ambystoma tigrinum acquire the ability to modulate their kinematic pattern depending on the environment.
The anal gland secretion of the European badger (Meles meles) and its role in social communication
Authors: DAVIES J. M. , LACHNO D. R. , ROPER T. J.
Published: March 2009

The aim of this study was to investigate the chemical profile and hence the potential biological function of anal gland secretion in the European badger (Meles meles). Samples of secretion collected from wild and captive animals were analysed using gas chromatography. Analysis of whole secretion revealed the scent profiles of all samples to be remarkably similar. No evidence was found to suggest that the secretion contained information about the individual identity or sex of its producer, although some evidence was found of group differences in odour profile. Analysis of methylated samples revealed the secretion to be of low volatility, containing a number of long‐chain (> C14) fatty acids, 15 of which were identified. The results are consistent with the idea that badger anal gland secretion functions as a long‐term territory marker.
Effects of environment on grey seal (Halichoerus grypus) pup mortality. Studies on the Isle of May
Authors: BAKER J. R. , BAKER R.
Published: March 2009

Breeding sites, including beach environment and topography, play a significant role in the causes of death of grey seal (Halichoerus grypus) pups, in particular the incidence of starvation, peritonitis/navel ill, other infectious diseases and injuries as a result of adult‐pup interactions. The bacteria involved are opportunistic invaders. A wide and differing sex ratio in dead pups was found on different beaches and this has not been satisfactorily explained.
Population ecology of Mus musculus on Mana Island, New Zealand
Authors: EFFORD M. G. , KARL B. J. , MOLLER H.
Published: March 2009

Feral house mice (Mus musculus) living on 217 ha Mana Island, New Zealand, with no mammalian predators, were snap‐trapped and autopsied. A 7‐month breeding season took the population from a spring low to extremely high density in autumn. Litters were largest in the middle of the breeding season, and significantly larger on Mana than on the New Zealand mainland. Litter size in early pregnancy was similar for young and old mice but more embryos were resorbed by old females. The breeding season ended in April when adult females stopped ovulating and young failed to mature. When the population declined over winter no animals bred, they all lost weight, and even previously mature males lost their reproductive ability. Mice continue to grow throughout life and become larger than mice in most populations on the New Zealand mainland. The regular and pronounced seasonal pulse in Mana's mouse population contrasts with longer‐term fluctuations generally seen in mainland populations at lower density in indigenous forest. These differences may be explained by absence of predators, habitat features or lack of any chance to disperse on the island.
Predation on ground‐nesting seabirds by island populations of red deer Cervus elaphus and sheep Ovis
Authors: FURNESS R. W.
Published: March 2009

On Foula, Shetland, sheep were observed biting off the legs, wings or head of unfledged young Arctic terns. Large numbers of tern chicks and a few Arctic skua chicks were found with amputations characteristic of these attacks by sheep. On Rhum, Inner Hebrides, red deer were watched biting the heads off manx shearwater chicks and occasionally also chewing the shearwaters' legs and wings to excise bone. Killing of birds and the selective ingestion of bone‐rich parts by ruminants has not previously been widely documented. It is presumably a response to mineral deficiencies in the vegetation, and it may only occur in rare situations where ruminants feed on mineral‐deficient vegetation on which there are dense colonies of ground‐nesting birds.
The distribution of faeces by the Spanish lynx (Felis pardina)
Authors: ROBINSON I. H. , DELIBES M.
Published: March 2009

The distribution of faeces of the Spanish lynx was observed in the Biological Reserve of Dofiana during October 1985. Faeces were non‐randomly distributed on tracks through the vegetation, and occurred more frequently than expected beside intersections of deer trails with the tracks.

A computer simulation showed that a randomly moving lynx was more likely to encounter faeces when they occurred at intersection points than when they occurred randomly on tracks.

I.R. would like to thank Dr J. Castroviejo for permission to work in the Biological Reserve of Dofiana. Thanks are also due to R. Laffitte for help in the field, and to A. Blom for discussions about the work. Dr M. L. Gorman provided useful comments on earlier drafts of this manuscript, as did Dr G. J. Pierce who also gave advice about the computer simulations. The investigation was supported by a grant to I.R. from the Mammal Society and the University of Aberdeen's Skene and Cran bequest funds, and by project No. 944 of CSIC‐CAICYT (Spain).
The influence of riparian vegetation on macroinvertebrate community structure in four Hong Kong streams
Authors: DUDGEON DAVID
Published: March 2009

The benthic macroinvertebrate communities of four Hong Kong streams with similar water chemistry but differing riparian conditions were investigated. Differences in chlorophylls and detritus standing stocks reflected the degree of shading by riparian vegetation; Tai Po Kau Forest Stream (TPKFS) and Bride's Pool (BP) had an allochthonous food base while autochthonous energy sources were relatively more important in Lam Tsuen River (LTR) and Pui O Stream (POS). The macrobenthos was dominated by aquatic insects and morphospecies richness (excluding Chironomidac) ranged from 70 (POS) to 94 (TPKFS). Differences in total macroinvertebrate abundance across sites were not related to chlorophylls or detritus.

Highly significant differences in the morphospecies comprising the most numerous taxa at each site were observed, and TPKS and BP were more similar to each other than to the LTR‐POS pair with respect to top‐ranked taxa. Intraspecific comparisons of the abundance of these taxa revealed significant differences for 23 out of 30 morphospecies. Multiple regression of the abundance of key morphospecies against independent variables (chlorophylls a, b and c, total chlorophyll and detritus) yielded significant best‐fit models for all taxa showing intersite differences in abundance. These data can be interpreted as reflecting the influence of riparian vegetation on stream community structure via an effect on food supply. The results were discussed with reference to the applicability of the River Continuum Concept in the tropics.
Evidence for echolocation in the common shrew, Sorex araneus
Authors: FORSMAN K. A. , MALMQUIST M. G.
Published: March 2009

In this laboratory experiment it is shown that, like four North American soricid shrew species, the European common shrew Sorex araneus L. is able to use echolocation to identify open and closed tubes at a distance of 200 mm.

Three common shrews captured in Sweden were used for the experiments, which were carried out in darkness and within a sound‐proof box. The experimental set‐up eliminated orientation using sight, sound or scent from outside the experimental cage. Echolocation calls consisted of broadband ultrasonic clicks at low sound pressure. These were recorded using an ultrasound detector.

The ecological significance of echolocation in shrews is discussed. It is proposed that common shrews use echolocation to locate protective cover, thus minimizing the risk to be taken by, e.g. owls.

Echolocation may also be used for detecting obstacles in subterranean tunnels. Hence, echolocation could be of certain importance when abandoned burrows in the periphery of the tunnel system are restored during periods of increasing population densities. Since density peaks in most populations occur regularly each summer, and may reach extreme magnitudes in cyclic populations, the ecological significance of echolocation in shrews may be considerabl.
Drilling by Octopus vulgaris(Mollusca: Cephalopoda) in the Mediterranean
Authors: NIXON MARION , MACONNACHIE ELAINE
Published: March 2009

Octopus vulgaris drills holes in the shells of a variety of molluscs. The walls of the cavities drilled exhibit dissolution of mineral and organic material. The features which characterize the cavities have been described. The composition and structure of the shell itself is important in determining the size, shape and form of the cavity drilled, and not the size of the octopus. Capture, drilling the shell, and eating the occupant may take less than one hour.
Contraception, reproduction and demography of free‐ranging Etosha lions (Panthera leo)
Authors: ORFORD H. J. L. , PERRIN M. R. , BERRY H. H.
Published: March 2009

The use of long‐acting contraceptives as an effective population control mechanism for free‐ranging lions was investigated during a three‐year study in the Etosha National Park on five lion prides. Lions were immobilized with ketamine hydrochloride and xylazine hydrochloride. Following immobilization, lionesses were weighed, measured and aged, while serum steroid hormone levels were analysed and vaginal smears were obtained. Physical condition and sexual state were assessed. Individuals were used as control animals or given melengestrol acetate (contraceptive) implants, branded and released; the animals were observed for possible changes in behaviour, birth rate and mortality. Ten treated lionesses were recaptured at irregular intervals to reassess weight and steroid hormone levels, while three lionesses had their implants removed to determine if their fertility would return. The contraceptives prevented pregnancy, were reversible when removed and did not alter lion behaviour significantly, except that sexual behaviour was not recorded in treated lionesses.
Succinic dehydrogenase activity in the epidermis ofNatrix piscator during its sloughing cycle
Authors: Mittal A. K. , Singh J. P. N. , Singh S. K.
Published: March 2009

Succinic dehydrogenase activity, in the epidermis of Nairix piscutor in different stages of sloughing cycle, has been localized using a nitro‐BT technique with appropriate controls. The staining properties of different layers in scale epidermis are similar to the corresponding layers in hinge epidermis.

In the stratum germinativum, the layers of undifferentiated epidermal cells in all stages of the sloughing cycle, and in the lacunar tissue of Stages 3,4 and 5, a positive though weak reaction for SDH activity reflects the active metabolic state of the cells in these layers. Loss of SDH activity in Stage 6 indicates an inactive metabolic state of the lacunar tissue cells, corresponding with their disintegration owing to the cessation of nutrients as a result of keratinization of cells in the underlying layers.

The Oberhautchen, mesos and alpha layers in all Stages, and the clear layer cells in Stages 5 and 6 (outer epidermal generation), the presumptive Oberhautchen, presumptive mesos layer and presumptive alpha layer in all stages of their differentiation, and the presumptive beta layer in Stages 3 and 4 (inner epidermal generation) all stain purple with nitro‐BT technique even in sections incubated in the medium without the substrate‐succinate. The reaction is inhibited by prior treatment with 0.1 M N‐ethyl maleimide blocking protein‐bound ‐SH groups. This suggests that the reaction is due to the presence of protein‐bound ‐SH groups in these sites. The reduced intensity of reaction in the mature beta layer of the outer epidermal generation, and in the presumptive beta layer in Stages 5 and 6 of the inner epidermal generation, is due to simultaneous loss of their content of ‐SH groups with maturation and keratinization.
Anatomy and ultrastructure of the ventral pharyngeal organs of Saccocirrus(Saccocirridae) and Protodriloides(Protodriloidae fam. n.) with remarks on the phylogenetic relationships within the Protodrilida (Annelida: Polychaeta)
Authors: Purschke G. , Jouin C.
Published: March 2009

General anatomy and ultrastructure of the ventral pharyngeal organs were investigated in Succocirrus krusudensis, Protodriloides chaetifer and P. symbioticus. Succocirrus papillocercus, a species without a ventral pharyngeal organ, was included for comparison. The two genera show homologous similarities in their pharynges: bulbus muscle composed of transverse muscle fibres and interstitial cells, those cells with small cell bodies and processes containing prominent tonofilaments which are orientated dorsoventrally and connect the bulbus epithelium with the investing muscle; bulbus muscle fibres circomyarian with nuclei and mitochondria located basally, investing muscle also with interstitial cells, which lack tonofilaments; oesophagus surrounded by gland cells opening into the pharynx. Most likely, a ventral pharynx with these characters was already present in the stem species of Saccocirridae, Protodriloidae fam. n. and Protodrilidae and evolutionary processes led to several changes: a tongue‐like organ with a prominent tip and supporting elements is a synapomorphic character of Protodrilus and Succocirrus; the pharyngeal organ is reduced to stomodeal pouches and salivary glands in S. papillocercus and completely lost in Asromus raenioides. These results and data from previous studies are summarized in a tentative phylogenetic dendrogram and allow the introduction of a new family, Protodriloidae.
The reproductive cycle of male tomb bats, Taphozous hildegardeae (Chiroptera: Emballonuridae), in a seasonal environment of the African tropics
Authors: McWilliam Andrew N.
Published: March 2009

Two cave populations of Hildegarde's tomb bat had a reproductive cycle that corresponded closely to the rainfall‐induced seasonality of coastal Kenya (4s). Males had pronounced bimodal cycles of body weight due to the deposition of fat during periods of relative food abundance in both rainy seasons, and fat depletion during competitive mating and the dry seasons, when numbers of moths were lowest. The main period of sexual regeneration coincided with the increase in body weight experienced during the ‘long rains’ [April‐June) and led to mating. A secondary peak in the weights of male sexual glands, associated with the increase in body weight that occurred in the ‘short rains’ (October‐December), did not result in reproduction. It is suggested that this latter period of sexual activity was related to the maintenance of year‐round harems, and may represent the male response to a vestigial, bimodally polyoestrous, reproductive cycle.
Energy requirements of fat sand rats (Psammomys obesus) and their efficiency of utilization of the saltbush Atriplex halimus for maintenance
Authors: Degen A. Allan , Kam M. , Jurgrau Debbie
Published: March 2009

The fat sand rat (Psammomys obesus; Gerbillinae), a diurnal gerbillid rodent, is herbivorous and able to thrive while consuming only the saltbush Atriplex halimus (Chenopodiaceae), a plant relatively low in energy content and high in ash and water. We measured the basal metabolic rate offat sand rats, their energy requirements in captivity when they were offered only A. halimus, and their efficiency of utilization of this diet for maintenance.

Before consuming A. halimus leaves, the fat sand rats scraped off the surface layers with their teeth. This behavioural activity removed 6.4% to 8.5% of the dry matter of the leaf, but increased the gross energy and organic matter content of the leaf by only approximately 3.1%. Basal metabolic rate of the fat sand rats was 167.9 kJ.kg‐O 7s d‐′, approximately 57% of that expected for an eutherian mammal of its body mass, and energy requirements for maintenance, or average daily metabolic rate, were 498.7 kJ.kg‐0′7s d‐′, approximately 90% of that expected for a rodent of its body mass. Dry matter digestibility of the consumed A. halimus averaged 67% and apparent digestible energy and apparent metabolizable energy averaged 65.3% and 63.4% of the gross energy, respectively. The efficiency of utilization of A . halimus for maintenance energy (k,) by the fat sand rats was 0.32 and the heat increment of feeding (HIF) was 0.68. The k, of A. halimus appeared to be low compared to other feeds, and this characteristic plus its low energy value and high water content forced the fat sand rats to consume large quantities of forage for maintenance.

It was concluded that although A. halimus has a low energy and high ash content, there are several advantages for fat sand rats consuming mainly this diet. Among them are: (1) it provides a more stable diet throughout the year than do seeds; (2) fat sand rats have no competition for this food resource from other rodents; and (3) their burrows are at the base of the
Morphological characteristics of the masseter muscle of 22 ruminant species
Authors: Axmacher H. , Hofmann R. R.
Published: March 2009

The bilateral masseter muscle was dissected from formalin preserved heads of 41 ruminants belonging to 22 species and three feeding types. Topographic relations of the masseter portions were reexamined in relation to mandibular shape. In contrast to earlier observations, masseter weight is significantly correlated with body weight irrespective of body size and feeding type, amounting in all ruminants to approximately 0.20% of body weight. Morphophysiological differences in masseter attachment and leverage are due to the different arrangements of masseter muscle tissue.
Chemical signalling and monopolization of nectar resources by territorial Pachymelus limbatus (Hymenoptera Anthophoridae) male bees in Madagascar
Authors: Nilsson L. Anders , Rabakonandrianina Elisabeth
Published: March 2009

Observations on territoriality and the associated odour‐marking and foraging behaviours in male Pachymelus limbarus Saussure, a Malagasy endemic anthophorid bee, are reported. Data indicated a monandrous mating system where virgin females are attracted, probably by pheromonal cues, to male‐patrolled territories associated with flowering, nectariferous Plectran‐ rhussensu lato species (Lamiaceae). One male observed in detail applied odour marks every 30–80 minutes on twigs around a food‐resource area that contained c. 850 flowers. This marking behaviour always preceded territory residence. The male spent c. 80% of his time patrolling. Meanwhile, any intruding flying insect was inspected or chased, which caused conspecific males, as well as often females, to leave the site. The resident male fed frequently on flowers within his territory (c. 3,600 flower‐visits on fine days), except immediately following odour‐marking bouts. His flower‐visiting was often released by interactions with intruding insects entering the territory. The observations provide the first example of male territoriality based on resource defence polygyny in the bee family Anthophoridae. The importance of resource distribution in the evolution of male territoriality in bees is discussed.
Tooth wear in eastern grey kangaroos (Macropus giganteus) and western grey kangaroos (Macropus fuliginosus), and its potential influence on diet selection, digestion and population parameters
Authors: McArthur Clare , Sanson G. D.
Published: March 2009

As teeth wear in eastern and western grey kangaroos, the pattern of enamel ridges changes. This affects the amount of available cutting edges and consequently the masticatory efficiency. These kangaroos also have molar progression. There is evidence for the independence of rates of tooth wear and molar progression, and variation is found in the maximum amount of wear attained by teeth both within and between populations. This variation has the potential to affect diet selection, digestion and population parameters.
The chemosensory behaviour of Lithobius forficatus (Myriapoda: Chilopoda). 2. Bioassay and chemistry of the coxal pheromone
Authors: Littlewood P. M. H.
Published: March 2009

The common brown centipede, Lithobius jorJcatus (L.), releases a sex‐specific pheromone which emanates from distinctive cuticular openings on the coxae of the hind legs‐the coxal pores (Littlewood & Blower, 1987). The pheromone can be isolated from tissue extracts of the coxal organs (surrounding the coxal pores) and from substrata which have been 'marked by male or female L. forjcatus and presented to centipedes in the form of a behavioural bio‐assay.

In this paper, further evidence is presented for a centipede pheromone, the chemical components of male and female secretions are separated using Gas Layer Chromatography (GLC), a qualitative chemical analysis is described and the nature of the pheromone is discussed.
Morphometric analysis of the gills of the European eel, Anguilla anguilla
Authors: Bennett M. B.
Published: March 2009

The gills of the European eel, Anguilla unguilla L. were analysed morphometrically. Fresh (unfixed) gills and resin‐replica casts of the branchial vascular system were examined. The total gill surface area was found to be proportional to (body mas)0‐715 for fish of between 60 and 1 160 g. This relationship between gill surfxe area and body mass was maintained irrespective of a reduction in body mass produced by fasting. Vessel dimensions were obtained from the vascular casts. Calculations made using these values suggest that the major sites of gill vascular resistance lie at the level of the afferent lamellar arterioles and the secondary lamellae.
Effects of egg size and composition on the size, quality and survival of lapwing Vanellus vanellus chicks
Authors: Galbraith H.
Published: March 2009

The influence of egg size and composition on the size, quality and survival of lapwing chicks was examined on two farmland study sites in the Midland Valley of Scotland. Eggs comprised 33.1% yolk, 61.3% albumen and 5.6% shell. Whereas the yolk and shell proportions decreased with increasing egg size, the albumen proportion increased. Most variation in egg size was attributable to differences between females but was also influenced by clutch number (eggs in replacement clutches on the rough grazing, but not the arable, site were smaller), clutch size (eggs were smaller in smaller clutches), maternal body condition (females in good condition produced larger eggs) and habitat (since females on the arable site fed more successfully, they were in better condition and laid larger eggs). Chick size, weight and survival were all influenced by egg size. The incubation period varied between 21 and 28 days (mean = 25.2) and was shorter in clutches laid later in the season.
Haematological studies on wild black rhinoceros (Diceros bicornis)‐evidence of an unstable haemoglobin
Authors: Paul Beverley , Toit R. Du , Lloyd Shän , Mandisodza A.
Published: March 2009

Baseline haematological data were obtained through routine analyses of blood samples from 31 wild black rhinoceroses captured in the Mana Pools National Park, Zimbabwe. Additional tests showed that the haemoglobin of this population is unstable; this observation helps explain the attacks of acute intravascular haemolysis documented in captive animals.
A study of home range and movements in the hedgehog (Erinaceus europaeus)
Authors: Morris P. A.
Published: March 2009

Radio‐tagged hedgehogs were studied on an area of traditionally managed farmland to obtain information about distances travelled and range areas used per night in this habitat. Data from five animals were obtained on 62 hedgehog/nights. Twelve of the data sets were eliminated owing to their incompleteness; observations of three animals (totalling 45 hedgehog/nights of acceptable data) were critically examined to establish basic procedures for future comparative studies. The concept of ‘home range’ is discussed in relation to the duration of study periods.
The vascularization of the choroid plexus of the lateral ventricle of the turtle Pseudemys scripta elegans (Reptilia)
Authors: Weiger T. , Lametschwandtner A.
Published: March 2009

The vascularization of the choroid plexus of the lateral ventricle of the turtle (Pseudemys scripta elegans) has been studied by means of vascular corrosion casts and transmission electron microscopy (TEM). A single arterial supply via the choroidal artery and a two‐fold venous drainage was found. By its form the plexus was subdivided into two parts: the body, and numerous villi projecting out of the body. The body consists of large convoluted arteries and veins which are covered by a network of vessels always greater than 15 μm in diameter. The villi are composed of a head consisting of vessels with a diameter of 16–50 μm and a stalk represented by one arteriole and one or two veins, which unite at the base of the stalk. An arteriovenous shunt occurs occasionally at the base of the stalk. By their angioarchitecture, six types of villi can be discerned: simple, club‐shaped, flat, wrinkled, glomus‐like and basket‐like villi. Garland vessels were present around arteries only. In ultrathin sections the vessels of the head of a villus possess a thin endothelium with tentacle‐like flaps which protrude into the lumen and many pinocytotic vesicles. These vessels were surrounded by a very fragmentary basement membrane and a dense layer of collagen fibrils.

It is suggested that the different areas in the plexus, i.e. the various villi and the body, represent areas with different physiological functions
Food resources of the wild Barbary macaque (Macaca sylvanus) in high‐altitude fir forest, Ghomaran Rif, Morocco
Authors: Mehlman P. T.
Published: March 2009

A small geographically isolated population of the Barbary macaque inhabits a high‐altitude fir forest habitat (Abies pinsapo) in the Ghomaran region of the Rif mountains of northern Morocco. The climate of this region is Mediterranean, but the altitude (1600–2100 m) causes winters to be cold (as low as ‐8.0 d̀C) with snow occurring from November to May (snowfall as deep as 1.5 m). The primary winter feeding adaptation is the ability to ingest high quantities of fir foliage; in spring, the macaques took a high diversity of leafy food items from all vegetation layers; in summer, the macaques foraged terrestrially for a high diversity of food items including seeds, small fruits, bulbous geophytes, and animal foods (including tadpoles from small streams); in autumn, the macaques returned to arboreal foraging, primarily feeding on oak acorns (Quercus ilex), fir seeds and yew fruit (Taxus baccata). The macaques were capable of ingesting 100 of 195 (51%) of all identified plant species in the region, although during the four‐month winter, the macaques only averaged 12.5 common food items. A comparison of the study area with the prime habitat of the Barbary macaque‐the high‐altitude cedar forests of the Moroccan Moyen Atlas‐indicates that climate and vegetation physiognomy are highly similar in both regions. Correspondingly, there is a high degree of similarity in macaque diet in both regions in terms of feeding behaviour by season, food diversity and specific feeding techniques. In the Ghomara, the winter feeding adaptation of fir foliage eating parallels that of the Barbary macaque in cedar forest (winter foraging for cedar foliage). This enables the Barbary macaque to exploit the Ghomaran fir forest habitat during the cold, snowy winters much the same as it does cedar forest habitat throughout a major portion of its geographical range.
Scrota1 melanins in bats (Chiroptera): description, distribution and function
Authors: Kermott L. H. , Timm R. M.
Published: March 2009

Several species of bats contain pigment granules within the scrotal skin, tunica vaginalis, or tunica albuginea surrounding the testis and/or epididymis. Seventy‐two species of bats, representing 49 genera were examined for the presence of such pigmentation. Histological, chemical and spectrophotometric tests were performed and confirmed the pigment as melanin. Melanin was found only in the families Pteropidae, Megadermatidae, Myzopodidae and Vespertilionidae. A strong correlation exists between scrotal pigmentation and roosting in locations where the bats are exposed to solar radiation. Melanin pigmentation in the scrotal region appears to be an adaption protecting male germinal tissue from the harmful effects of ultraviolet radiation. In one species, Laoiu frons, melanin deposited within the scrotal skin appears to have a social/reproductive communication function.
Field observations of the sexual behaviour of the smooth newt, Triturus vulgaris vulgaris (Amphibia: Salamandridae)
Authors: Verrell P. , McCabe Norah
Published: March 2009

This study reports observations of smooth newts, Triturus vulgaris vulgaris, breeding in a pond in southern England. Efforts were made to collect data on the timing of oviposition and on sexual behaviour during the breeding seasons of 1985 and 1986. Despite some between‐year differences in the timing of certain events, the qualitative pattern of reproduction was similar in both years. Courtship interactions were seen most frequently during a relatively short period of time before females began laying their eggs, which occurred in a highly synchronized manner. It seems likely that the probability of any one courtship encounter resulting in spermatophore transfer was low. Males competed for mates by chasing females and by interfering with one another's courtships, but no overt aggression was seen. Females appeared to find such male‐male interactions ‘aversive’. Scramble competition between males was most intense when the majority of females in the population were laying their eggs and were unresponsive to courtship. The mating system of the smooth newt most closely resembles a lek in which the intensity of sexual selection among males varies as a function of female availability.
Mechanics of locomotion and jumping in the horse (Equus): in vivo stress in the tibia and metatarsus
Authors: Biewener A. A. , Thomason J. J. , Lanyon L. E.
Published: March 2009

Principal stresses acting in the midshaft cortices of the tibia and metatarsus of the horse were determined from in vivo rosette strain gauge recordings for overground locomotion at different gaits, as well as for jumping and acceleration. Bone stresses were correlated with limb kinematics and ground reaction forces. The results for these two hind limb bones were compared to earlier determinations of locomotor stress in the forelimb radius and metacarpus (Biewener, Thomason & Lanyon, 1983b). Peak stresses generally increased with increasing speed; however, because of greater bending, stresses in the tibia were substantially higher (45%) than in the metatarsus over the range of steady state speeds. Bending of the tibia resulted from significant off‐axis loading by the ground reaction force. In contrast, the metatarsus was loaded in compression due to its close alignment with the ground reaction force. Peak stresses as high as ‐ 53 MPa (caudal cortex) in the tibia and ‐38 MPa (plantar cortex) in the metatarsus acted at a canter. Increased skeletal stress was matched by a corresponding increase in ground reaction force and a decrease in hind limb duty factor. In both bones, peak stresses were significantly greater and differed in their distribution during jumping and acceleration, compared to peak stresses during steady speed locomotion. Maximal values of ‐ 126 MPa (cranial cortex) in the tibia and ‐ 117 MPa (dorsal cortex) in the metatarsus were developed during jumping. These stresses are similar in magnitude to those reported for a range of different sized mammals during strenuous activity and correspond to a safety factor to yield failure of 1.5 to 3. Though generally consistent within an individual bone, the distribution and magnitude of stresses varied about 20% among individuals. This variation was greater for the metatarsus because of its lesser curvature, which diminishes the bone's ability to control for bending in a fixed direction.
Dental identification and age determination in Elephas maximus
Authors: Roth V. L. , Shoshani J.
Published: March 2009

The dentition of an elephant (fossil or extant) can yield clues to the animal's age species identity, provided the teeth are correctly identified. Identifying the serial category of elephant teeth is difficult because the size, shape and position of each tooth changes throughout life, as the teeth form, erupt, wear and move throught the jaw. In the present study, teeth from over 100 museum specimens of the Asian elephant (Elephas maximus) were the basis for establishing size ranges for cheek teeth in six serial categories (designated by Roman numerals I to VI). Although the teeth vary greatly and overlap in their dimensions, reliable identifications (as well as estimates of an individual's age in years) can be obtained using three or more measurements. An appreciation for dental variability in Elephas maximus will demand a re‐evaluastion of frequently‐cited examples of macroevolutionary patterns within the Elephantidae.
Injuries to jackass penguins (Spheniscus demersus): evidence for shark involvement
Authors: Randall B. M. , Randall R. M. , Compagno L. J. V.
Published: March 2009

An analysis is presented of records of injuries and the types of injuries to jackass penguins in Algoa Bay, South Africa, over a 10‐year‐period. Sharks are implicated in causing most of the injuries, but other possible agents are discussed. The types of injuries were categorized and compared to the dentition of sharks known to occur in the area. Using a life‐size model of a jackass penguin and preserved jaws of sharks, bites were simulated to establish the types of injury inflicted by different species. Certain injuries indicate attack by great white sharks, while others cannot be ascribed to any particular species. Most shark injuries show single jaw involvement, and range from small cuts across the feathers to the bird being cut in two. Sharks accounted for the highest number of identifiable natural causes of death, but the significance of shark attack as a mortality factor in jackass penguins is difficult to assess.
Reproductive biology and ecology of female polar bears (Ursus maritimus)
Authors: Ramsay M. A. , Stirling Ian
Published: March 2009

Data on age‐specific natality rates, litter size, interbirth interval, age of first reproduction, reproductive senescence, age of weaning and cub survival were determined for a free‐ranging population of polar bears inhabiting Hudson Bay, Canada, near the southern limit of the species range. Serum progesterone levels were also determined for females at different stages of their reproductive cycle to provide corroborative support for the reproductive parameters described. Animals were live captured using immobilizing drugs and each animal uniquely marked for future identification. First parturition occurred at four or five years of age and the age‐specific natality rate increased with age until approximately 20 years, after which it dropped markedly. At least 40% of adult females displayed two‐year interbirth intervals and 55% of cubs in their second year were independent of their mother. Mean size of cub litters in spring was 1.9 and 13% of litters had three or more cubs. The natality rate for 5–20‐year‐old females was estimated as 0.9, higher than that reported for any more northerly polar bear populations where two‐year interbirth intervals are rare, fewer than 5% of yearling cubs are weaned and triplet litters occur with less than 1% frequency. Cub mortality was initially high and declined with age. Although cubs in western Hudson Bay were weaned at a younger age and a lighter weight than their counterparts in more northern populations, cub mortality rates were similar. The reason for the marked differences in reproductive parameters in the western Hudson Bay population is not known. We speculate that sea‐ice conditions may be sufficiently different to allow weaned bears at a lighter body weight to hunt seals more successfully there than further north.
Overwintering strategies of the badger, Meles meles, at 57 °N
Authors: Fowler P. A. , Racey P. A.
Published: March 2009

Over two eight‐month periods (October/November‐May) during successive winters (1983/4 and 1984/5), the body temperatures and activity patterns of captive badgers, Meles meles, living under semi‐natural conditions, were studied at 57 d̀N in Scotland. Temperature‐sensitive radio transmitters and automated telemetry systems provided long‐term records of body temperatures and times badgers were absent from an artificial sett.

Badger body temperatures of 28–34 d̀C, significantly below euthermic levels, were recorded between October/November and March each winter, with differences between mean daily maxima and minima varying from 1.6 to 8.9 d̀C. This was associated with a reduction, by up to 90%, in the time that the badgers spent outside their sett in mid‐winter. Body temperatures did not show circadian cyclicity, but from February onwards most locomotor activity occurred between 22:00 and 02:00 GMT. The extent to which activity was concentrated around midnight increased with decreasing night length in spring.

The body temperatures of one female badger fell to a nadir of 28 d̀C immediately prior to ovo‐implantation. During post‐implantation gestation, the body temperature of this female rose steadily, but had reached only 34.6 d̀C at parturition.

Photoperiod correlated closely with seasonal changes in body temperatures and activity levels, and is suggested as the primary synchronizer of seasonal activity and body temperature cycles. Other environmental variables, particularly ambient temperature and snow‐cover, appeared to act as modulating influences on these cycles.

It is postulated that during the winter, when climatic conditions are responsible for a shortage of food and an increase in heat loss, winter lethargy is an adaptation which enables the European badger to maintain energy balance. Reduced activity and confinement within sheltered setts, together with reduced body temperatures, enable the badgers to rely heavily on energy stored in adipose tissue during the autumn.
Birthdate and survival in bighorn lambs (Ovis canadensis)
Authors: Festa‐Bianchet Marco
Published: March 2009

The relationship between parturition date and lamb survival was investigated among individually marked bighorn ewes in south‐western Alberta, Canada. Lambs were born from 17 May to 21 July. Most births occurred in the first two weeks of the lambing period. Lambs born in May enjoyed greater survival than lambs born in June and July. The viability of lambs born after 10 June was extremely low. Inadequate nutrition is suggested as the cause of greater mortality of lateborn lambs. Ewes that give birth late are at an earlier stage of lactation when forage quality declines and may not produce sufficient milk to ensure lamb survival. Their lambs have access to high‐quality forage for a shortened period. The proportion of late lambs appeared to be correlated with ewe density in the winter range.
Food‐habitat relationship of harbour seals and black cormorants in Skagerrak and Kattegat
Authors: Härkönen Tero J.
Published: March 2009

Comparative studies on the food of the black cormorant Phalacrocorax carbo and the harbour seal Phoca vitulina were carried out in two contrasting habitat types. Both species feed predominantly on bottom‐dwelling fish. Black cormorants are able to utilize fish found both on vegetation‐covered and naked sea beds at a water depth of less than 10 m, while harbour seals feed mainly on soft sea bottoms above 30 m where vegetation is scarce or lacking. The food overlap of the two piscivores is large in environments where large shallow sea bottoms are available, and small in areas where sea bottoms of soft material is found at greater depth. In areas where the shallow bottoms are covered by vegetation only, cormorants are able to feed on the fish species inhabiting this kind of environment. There is no evidence that these predators make a choice regarding prey species.
Survival of released pheasants, Phasianus colchicus, in Ireland
Authors: Robertson Peter A.
Published: March 2009

The survival of 250 hand‐reared pheasants was assessed by resightings of tagged individuals following their release into an open‐roofed pen on an estate in Ireland. The death rates per 10 days after release were approximated as 5.5% during the first 30 days, 11.6% between 31–70 days, 6.0% between 70–240 days and 2.3% between 241–365 days. The birds suffered their highest rate of loss (48.2%) during their first 10 days after leaving the release pen. This emergence‐related mortality was the major factor influencing changes in the observed death rate following release. Predators, mainly foxes, were initially attracted to the area by the presence of inaccessible prey. Males suffered a higher rate of loss following their emergence from the release pen than did the females, possibly associated with the greater proportion of time thereafter spent outside the pen and hence at risk. The factors affecting the survival of hand‐reared pheasants are discussed. It is suggested that reducing densities of birds within pens may increase subsequent survival without resorting to predator control.
The intrinsic rate of natural increase and reproductive effort in primates
Authors: Ross Caroline
Published: March 2009

The intrinsic rate of natural increase (rmax) is calculated for 58 primate species. It is found that this parameter is negatively correlated with body weight, so that larger primate species consistently have a lower rmax than do smaller species. Although there is no apparent link between the raw value of rmax and environmental predictability, a relationship between a high rmax, relative to body weight, and an unpredictable environment is found to exist. However, there is no relationship between a predictable environment and either the raw value of rmax, or the relative rmax. After body size effects are removed, rmax is not correlated with basal metabolic rate (BMR). Pre‐natal maternal investment (MI) is found to correlate highly with BMR, even after the removal of body weight effects. MI does not correlate either with rmax or with environmental predictability. Diet appears to have little influence either on rmax on MI, but there is some indication that folivores have both a high relative rmax and a high relative MI. These results are discussed in the light of theories of life‐history strategy evolution.