bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of scent marking in a free‐ranging, female black‐footed cat (Felis nigripes)
Authors: Molteno A. J. , Sliwa A. , Richardson P. R. K.
Published: February 2006

A radio‐collared, female black‐footed cat (Felis nigripes) was followed for a total period of 575 hours, over seven observation periods spanning 18 months, in the Kimberley region of the Northern Cape Province, South Africa. Data on reproduction and scent marking were collected by direct observation. The predominant form of scent marking was urine‐spraying, the frequency of which fluctuated during the year and seemed to be related to changes in the reproductive cycle. Marking frequency increased dramatically approximately one and a half months before mating, and conception of the first litter of the breeding season occurred at a low frequency during pregnancy, and was entirely absent when the cat was rearing young. This strongly indicates a primary function in the advertisement of female reproductive condition, although an additional role in the maintenance of social spacing is suggested. Scent marks were not restricted to the borders of the animal's range, but corresponded to those areas used most intensely during the year.
Quaternary radiation and genetic structure of the red fox Vulpes vulpes in the Mediterranean Basin, as revealed by allozymes and mitochondrial DNA
Authors: Frati F. , Hartl G.B. , Lovari S. , Delibes M. , Markov G.
Published: February 2006

The Quaternary dispersal of the red fox Vulpes vulpes in the Mediterranean area was evaluated through the study of allelic variation at 45 enzyme loci in 120 individuals from 10 sampling sites. A 375 bp fragment of the mitochondrial cytochrome b gene was also sequenced in a total of 41 specimens from the same sampling locations. Nine allozyme loci were polymorphic. The proportion of polymorphic loci per population (P) ranged from 0 to 15.6%, and expected average heterozygosity (H) from 0 to 4.4%. A total of 18 different Cyt b haplotypes were detected. Most of them were confined to only one population. Both allozyme and mtDNA data implied that our fox populations were genetically fairly isolated from one another, suggesting low gene flow between them. This isolation should be of comparatively recent origin according to the slight differentiation among Cyt b haplotypes. Fox populations appeared to belong to two genetically distinct groups. With a mean value of Nei's D = 0.024, genetic distance between these groups was similar to that detected at subspecies level in taxa of large mammals. This pattern may have originated from different colonization waves during Quaternary glaciations and deglaciations. Red foxes from Sardinia were more closely related to the Bulgarian foxes than to the Iberian ones. However, repeated introductions to Sardinia probably also occurred from Central Italy and Spain, as suggested by the presence of haplotype A and a typical Central Italian allele, Ck‐290.
Feeding behaviour of the termite‐eating planarian Microplana termitophaga (Platyhelminthes: Turbellaria: Tricladida: Terricola) in Zimbabwe
Authors: Jones H. D. , Cumming M. S.
Published: February 2006

The predatory behaviour of the terrestrial planarian Microplana termitophaga has been studied by a series of long‐term observations, video records and photographs. The planarians feed by ‘fishing’ for termites at the open vent of the mound of Odontotermes transvaalensis, mainly for 2 or 3 hours after dawn. Locomotion (primarily by ciliary gliding) is described and a full account is given of feeding behaviour, including the stalking and selection of prey, the method of capture (termites are bodily lifted out of the vent by the adhesive front end of the planarian) and the time course of feeding and digestion (typically about 6 min). The largest meal observed by one individual was of 13 termites consecutively consumed over 3 h 14 min. Large numbers of soldiers at the rim reduce the predation rate, though planarians can capture soldiers.
Geographic variation in growth of polar bears (Ursus maritimus)
Authors: Derocher A. E. , Stirling I.
Published: February 2006

The growth patterns of body length and head size in female and male polar bears (Ursus maritimus) in western Hudson Bay were compared with those of five other populations using the von Bertalanffy equation. Our objective was to determine if differences in growth patterns could account for higher reproductive rates reported in female polar bears from western Hudson Bay compared to the other populations. Significant differences in asymptotic size and growth rate were found in body length and head size. At age of first breeding in western Hudson Bay (4.1 years old), females reached 97% of asymptotic body length, while females in other populations took between 4.5 and 5.5 years to attain the same proportion. Body length of three‐ and four‐year‐old females in western Hudson Bay declined between the 1960s and 1990s and temporal variation in growth rates makes cross‐population studies uncertain. Zygomatic breadth and head length may provide the most useful measures to compare populations because they are simple to measure, non‐varying, and growth in head length is almost complete (97–98%) by the age of first breeding in females. We conclude that higher reproductive rates in western Hudson Bay were associated with higher growth rates. However, the reason for the higher growth rates remain unknown.
Individuality in the groans of fallow deer (Dama dama) bucks
Authors: Reby D. , Joachim J. , Lauga J. , Lek S. , Aulagnier S.
Published: February 2006

Vocal signatures and individual recognition are documented in a wide range of avian and mammalian species, but little is known about cervids. However, the existence of individual characteristics in cervid vocalizations is highly probable, as the individual morphology of their vocal organ determines the spectral structure of the uttered signal. Here, we report the presence of individual characteristics in the spectral structure of fallow deer groans recorded during the rutting period. We digitized 147 vocalizations from four adult males and transformed each of them into a power spectrum of 32 values in order to represent the frequency distribution of the sound power. A neural network discrimination with cross validation performed on the resulting variables allowed us correctly to identify 87.9 % of the tested vocalizations. The spectrum characteristics of an individual remained stable over the rutting period, and probably over several consecutive ruts (the vocalizations of one male recorded during a previous rutting period were also correctly classified). We therefore conclude that the groan may constitute a vocal signature. The individually structured groan may provide a valuable basis for individual recognition during the breeding season and therefore may play an important role in the social interactions observed during this period.
Sperm fertility and skewed paternity during sperm competition in the Australian long‐eared bat Nyctophilus geoffroyi (Chiroptera: Vespertilionidae)
Authors: Hosken David J.
Published: February 2006

Prolonged sperm storage, rare among mammals, is widespread among bats and may promote sperm competition, assuming stored sperm are fertile. However, while sperm storage has been documented in many bat species, there have been few investigations of the fertility of stored sperm. Related to this, and a fundamental question in the study of competition at the gametic level, is the effect of mating order on success during sperm competition. For mammals there are no clear mating order effects, in part because females do not store sperm for prolonged periods, but there have been no investigations of mating order effects during sperm competition in sperm‐storing bats. I report here on a study designed to investigate the fertility of stored sperm and the effects of mating order on success during sperm competition in a captive colony of Australian long‐eared bats Nyctophilus geoffroyi (Chiroptera: Vespertilionidae). Bats were housed in outdoor flight‐cages, under natural light and temperature regimes. Females were housed serially with two males and were separated from them at intervals throughout the year.

Blood plasma progesterone concentrations, measured using double antibody radioimmunoassay, were monitored to assess the duration of sperm storage. Paternity of offspring was assessed using genetic markers identified using gel electrophoresis of blood enzymes. Blood plasma progesterone concentrations were basal from early autumn till mid‐late winter, increased markedly during pregnancy, and generally fell back to basal 5–6 weeks post‐partum. Data indicated that females could store fertile sperm for more than 90 days, while sperm stored by males were fertile after 4–5 months' storage. Paternity was significantly biased toward one male which fathered all offspring. Results are discussed in the context of sperm competition.
Intra‐ and interspecific aggregation among dung beetles (Coleoptera: Scarabaeoidea) in an Alpine pasture
Authors: Palestrini C. , Barbero E. , Ronaldo A.
Published: February 2006

Spatial distribution of scarabeoid beetles on dung pats was studied in the Argentera Natural Park (south‐western Italian Alps) from June to September in 1994 and 1995. Artificial dung pats were distributed evenly within the study area (about 1400 m a.s.l.) and sampled at suitable dung ages (1–13 days). Two experimental tests were carried out. In the first test, experimental pats were covered with metallic nets which prevented the largest species from reaching the dung, whilst in the second test a variable number of individuals of large or relatively large species was added to the experimental pats.

The community was dominated by Aphodius species (19 out of 25 species), which usually were also the most abundant in the pats. The densities of most species were relatively low most of the time with average abundances lower than two individuals per pat. Even though some interspecific differences were observed, ecological overlap between species was rather high with regard both to seasonality and succession in the dropping. Manipulative tests suggested that small beetles were not excluded by larger beetles. Patterns of spatial distribution showed some degree of intra‐ and interspecific aggregation. Proximate mechanisms of aggregation are probably non‐specific. The ultimate cause of aggregation might be mate‐finding. Alternatively, individuals might aggregate because the very same presence of beetles within a dung pat would modify its chemical status improving its quality. Intraspecific aggregation (measured by means of the J index) was much higher than interspecific aggregation (C index) which suggests, according to the Aggregation Model, that interspecific coexistence might be facilitated. However, the data gave no evidence for intra‐ and interspecific competition between adult beetles.
Behaviour of lambs (Ovis aries) in relation to spatial patterns of defecation on a pasture
Authors: White K. A. J. , Hall S. J. G.
Published: February 2006

Twenty lambs (median body weight 37.2 kg) were kept on a paddock of 0.56 ha in England for four weeks in autumn. A 10 m grid was marked out in the paddock and from 10 of the 54 grid squares, all faeces were removed by hand at the start of each week. Faecal abundance was estimated by a point quadrat technique and observations of behaviour were made by scan sampling at intervals of 10 min during 15 h in each week. Each lamb produced on average 0.72 kg wet weight of faeces per day. Removal of faeces had no effect on grazing behaviour and the only correlation between faecal abundance and behaviour was that night lying tended to be on areas where faecal abundance was high. This was probably due to the lambs preferring certain areas for night lying and defecating heavily in these areas before starting to graze in the morning. Faecal encounter during daytime grazing was affected neither by sheep body weight nor by parasite burden. Behavioural mechanisms of avoidance of faeces are probably not detectable when behaviour is studied in the context of grid squares of 100 m2 and further study should include detailed observations on the grazing paths of individual sheep.
Helping Ethiopia's wildlife
Authors: Cotgreave Peter
Published: February 2006

In the Bible, Ethiopia is known as the land of Cush – an exotic and largely unknown territory. It was almost equally unfamiliar to Alfred Russell Wallace when he divided the world's animals into groups according to their geographic origins, but the country so fascinated him that he gave the name ‘Ethiopian Region’ to the whole of Africa. Later, Ethiopia escaped the extended periods of European colonization experienced by its neighbours, and the country remains in our minds one of the more exotic and mysterious areas of the world and a place of great zoological interest.
Territorial behaviour of a rainforest dragonfly Notiothemis robertsi (Odonata: Libellulidae): proposed functions of specific behavioural patterns
Authors: Clausnitzer Viola
Published: February 2006

The behaviour of this rainforest dragonfly was studied in the Kakamega Forest, West Kenya. Seven different activities were distinguished: perching, sun‐flights, patrolling, inspection, interspecific, intraspecific, and sexual flights. Two‐act sequences of these behaviours were analysed and quantified to determine significant transition probabilities. Sun‐flights into the tree canopies were the most common flight activity and followed any other behaviour significantly more often than expected. Coming back from a sun‐flight, the males preferentially perched or patrolled; after patrolling males typically perched. Most of the time the males spent perching in their territory (32% of total time in territory). Proposed functions of these territorial behavioural activities in Notiothemis robertsi are deduced from these results.
The role of unconscious selection in the domestication of sheep and goats
Authors: Zohary D. , Tchernov E. , Horwitz L. Kolska
Published: February 2006

It is proposed that many of the morphological, physiological and behavioural traits that characterize domestic sheep and goats and distinguish them from their wild ancestors (e.g. diminished sexual dimorphism; diminution in brain, body and horn size and changes in shape of the horns; changes in pelage coloration) were shaped, to a large extent, by unconscious selection. It is argued that once founder herds had been assembled and controlled by humans, the very transfer of these animals from their wild environments into the widely different human‐made husbandry system caused automatically drastic changes in selection pressures. Several adaptations, vital for survival in the wild, lost their fitness under the new conditions and broke down. New traits (which characterize domestic caprines) were promptly and unconsciously selected for. Protection from predators, culling of young males, protection from the elements, and changes in land use and in food and water supplies are considered the main ecological factors introduced by humans at the start of caprine domestication.

We evaluate the shifts in the selection pressures brought about by each of these changes, and sketch their expected impact on the morphology, physiology and behaviour of the human‐controlled herds. We also indicate which of the domestication traits (expected to be automatically selected for under the new set of conditions) are detectable in animal remains recovered from archaeological excavations.
Growth and food requirement flexibility in captive chicks of the European barn owl (Tyto alba)
Authors: Durant J. M. , Handrich Y.
Published: February 2006

The growth and the food requirements of the European barn owl (Tyto alba) were studied in three groups of captive chicks. One group of chicks, raised in ad libitum food conditions by their parents, was used to measure body mass and linear growth of a number of structural body components at their characteristic growth rate. A second group of chicks, hand‐raised with food ad libitum until fledging, was used to measure food requirement at the characteristic growth rate. A third group, hand‐raised with restricted feeding, was used to specify the plasticity of growth and food requirements still compatible with a normal development at fledging. Chicks of both sexes of the first two groups experienced an overshoot in body mass (maximum of 391 g) when approximately 40 days old, followed by a decrease (to a mass of 314 g) until fledging at 60 days old, giving a mass distribution with age in the form of a bell‐shaped curve. The daily food intake also showed a bell‐shaped curve with a peak value of 80 ± 10 g of fresh mice/day when the body mass was maximum. The decrease of food intake preceding fledging was spontaneous. The average daily food intake was 67 ± 17 g/day between the ages of 20 and 60 days. In the restricted feeding group, however, the same timing for linear growth and fledging was achieved with a 17% reduction of daily food intake. For the same fledging body mass as the ad libitum fed group, there was a flattening of the body mass curve. The significance of the overshoot in body mass and food intake is discussed in terms of the chick's and brood's advantages and in terms of parental investment in this species with hatching asynchrony.
Do patterns of helminth parasitism differ between groups of wild‐living cats in Scotland?
Authors: Delahay R. J. , Daniels M. J. , Macdonald D. W. , McGuire K. , Balharry D.
Published: February 2006

Differences in the prevalence and abundance of helminth parasites amongst host populations may result from variations in resistance to infection, differences in habitat preferences, diet or social behaviour. The use of helminth parasites as ‘ecological markers’ for determining differences between morphological groups of wild‐living cats in Scotland was investigated, in light of the debate over the definition of a wildcat. The prevalence and abundance of the tapeworm Taenia taeniaeformis did not differ significantly between cats designated as ‘wild’ and ‘feral’ types. The prevalence of both helminths was high (94% and 69%, respectively) and there was significant variation in worm abundance related to season and geographical area. Also, prevalence of infection with Toxocara cati was significantly higher in female cats. Cats which harboured large numbers of one worm species were also likely to harbour large numbers of the other. However, a possible relationship with cat condition was only found for T. taeniaeformis for which there was a significant negative correlation between an index of cat condition and worm abundance amongst ‘wild type’ cats, but not amongst ‘feral type’ cats. Variations in worm burdens could not be attributed to differences in the diet of the cats as there was no significant relationship between the presence of any individual prey type and either the presence or abundance of T. cati or T. taeniaeformis. There was a significant negative correlation between density and biomass of individual worms in infections of T. taeniaeformis, suggestive of a density‐dependent constraint on tapeworm growth.
Morphological differentiation in Mus spicilegus and the taxonomic status of mound‐building mice from the Adriatic coast of Yugoslavia
Authors: Krystufek B. , Macholán M.
Published: February 2006

The systematic status of a mound‐building mouse population from the Adriatic coast at Ulcinj, Montenegro (Yugoslavia), originally reported as M. hortulanus ssp., is assessed using morphological and morphometric analyses. This population was compared to other M. spicilegus samples from Ukraine & Moldavia, Voivodina (Yugoslavia) and Austria, and to M. macedonicus from Turkey, Greece, and Macedonia. Character states of selected non‐metric traits, along with the presence of a typical mound‐building behaviour, allowed classification of the study population with M. spicilegus. This was also supported by Canonical Variate Analysis on size‐adjusted dental traits. Uni‐ and multivariate morphometric studies revealed marked differentiation between the Ulcinj sample and the remaining M. spicilegus populations. The great deal of morphological divergence suggests a distinct systematic position of the Adriatic population, here described as Mus spicilegus adriaticus ssp. nova. Hypotheses about the possible origin and evolutionary history of the two eastern aboriginal mouse species are discussed.
Geographic variation of wing morphology in three Eurasian populations of the fruit fly, Drosophila lummei
Authors: Haas Heather L. , Tolley Krystal A.
Published: February 2006

Differences in wing morphology are described for three Eurasian populations of Drosophila lummei. A truss network of wing characters was used to quantify wing size and shape for 149 individuals from Japan, Sweden and Russia. Sexual dimorphism in wing size and shape was not substantial, so the sexes were pooled and multivariate analyses conducted. Both principal components analysis and discriminant analysis of wing morphology revealed significant differences among all geographic groups. These differences indicate that morphometric analysis of wing characters can reliably discriminate between geographic groups and accurately classify individuals of the three Drosophila lummei populations. Principal components analysis also revealed that characters occurring in the same section of the wing formed correlated suites which corresponded to morphologically and functionally distinct areas of the wing. This study is unique because it detects subtle morphological differences within a single species of fruit fly across an intercontinental distribution.The results corroborate genetic studies in which geographic variation was found for inversion polymorphisms among spatially separated populations of Drosophila lummei.
Evidence that minor directional asymmetry is functional in lizard hindlimbs
Authors: Seligmann Hervé
Published: February 2006

I examined directional asymmetry (DA) in the number of subdigital lamellae under the fourth toe (MDA) and in injury frequency (IDA) on the hindlimbs of eight Agamidae. In no species were MDA and IDA statistically significant, neither was there significant sexual dimorphism in MDA. But a strong, positive relationship exists between MDA and IDA, contrasting with the weak positive correlation between the side of injury and the morphologically dominant side in individual lizards. Therefore the relationship between MDA and IDA results from an evolutionary process, probably involving higher survival after injury of the morphologically dominant side. This process suggests functional importance of DA in the frame of evolution caused by unsuccessful predation.
A case of snake predation upon bats in northern Morocco: some implications for designing bat grilles
Authors: Hammer M. , Arlettaz R.
Published: February 2006

During a study of North African mouse‐eared bats in Morocco in August 1993 (Arlettaz et al., 1997) some accidental observations on chiropterophagy by the snake Coluber hippocrepis were made. This adds a new species to the list of bat‐eating serpents documented so far (for a general review see Schätti, 1984). In addition, our observations lead to some recommendations for the construction of bat grilles at underground sites to minimize predation risk by snakes or other predators upon bats.
Longevity in the European free‐tailed bat (Tadarida teniotis)
Authors: Ibáñez C. , Pérez‐Jordá J. L.
Published: February 2006

Numerous studies have documented that bats are unusually long‐lived for small mammals (Tuttle & Stevenson, 1982; Jürgens & Prothero, 1987 and references therein). In the absence of data on overall population dynamics, longevity can be an important demographic parameter for interspecific comparisons (Tuttle & Stevenson, 1982). Here, we present the first data on the longevity of a small population of Tadarida teniotis.
Habitat around maternity roosts of the 55 kHz phonic type of pipistrelle bats (Pipistrellus pipistrellus)
Authors: Oakeley S. F. , Jones G.
Published: February 2006

We quantified the percentage cover of habitats and the extent of linear features within 2 km of 11 maternity roosts of the 55 kHz phonic type of pipistelles Pipistrellus pipistrellus in south‐west England, and compared these with habitats around random points. The dominant habitats around both roosts and random points were improved grassland and built‐up areas. There was significantly more water (especially water edge habitat with woodland or hedgerow on the banks), and continuous hedgerow with emergent trees, around roosts. Preference for freshwater habitats around roosts was shown in comparisons of single habitats, and in compositional analyses with and without the inclusion of urbanized random points. These habitats may be preferred by 55 kHz pipistrelles: riparian habitats support large numbers of flying insects of the types eaten by 55 kHz pipistrelles, and hedgerows may be important linear features used by bats. The conservation of continuous hedgerows and watercourses close to maternity roosts would appear to be very important for 55 kHz pipistrelles.
Ship rats Rattus rattus on the Shiant Islands, Hebrides, Scotland
Authors: Key G. , Fielding A. H. , Goulding M. J. , Holm R. S. , Stevens‐Wood B.
Published: February 2006

The ship rat Rattus rattus was once widespread throughout the U.K. It is now an endangered species with an estimated 1000 or fewer individuals present in the U.K. and the species is listed in the red data book for British mammals (Morris, 1993). However, it is listed under schedule 9 of the U.K. Wildlife and Countryside Act (1981) as a non‐native species that should not be released into the wild.
Food habits and ranging behaviour of a group of farm cats (Felis catus) in a Swiss mountainous area
Authors: Weber J.‐M. , Dailly L.
Published: February 2006

Domestic cats (Felis catus) living in rural areas – hereafter named ‘farm cats’ (Liberg & Sandell, 1988) – show a highly variable degree of dependence on man (Macdonald, 1991). They generally benefit from human presence by getting household food and shelter for resting and reproduction (Niewold, 1986). Nevertheless, despite regular food provisioning by man and as long as their movements are not controlled by their ‘owner’, most farm cats remain active hunters and still feed to a variable extent on wild prey, particularly lagomorphs, rodents and birds (Goldschmidt‐Rothschild & Lüps, 1976; Liberg, 1984; Carss, 1995, amongst others), having sometimes a significant impact on prey species (Fitzgerald, 1988).
Cyprinid prey remains in otter Lutra lutra faeces: some words of caution
Authors: Carss D. N. , Nelson K. C.
Published: February 2006

This study investigates errors associated with the recovery of cyprinid remains in otter Lutra lutra spraints. Cyprinid fishes (Cyprinidae – the carps) comprise the largest family of freshwater fishes in the world with around 2000 known species. They form the major group of freshwater fishes in Europe with a total of 80 species, 16 of which occur in Britain (Winfield & Nelson, 1991). These fishes are commonly taken by otters Lutra lutra throughout the predator's geographical range, their prevalence in the diet apparently varying in relation to their abundance. No more than three species are commonly recorded as otter prey in Britain, Ireland, and Scandinavia (e.g. Wise, Linn & Kennedy, 1981; Kyne, Smal & Fairley, 1989; Erlinge, 1967, respectively), while at least five are in eastern Poland and southern Spain (e.g. Brzezinski, Jedrzejewski & Jedrzejewska, 1993; Lopez‐Nieves & Hernando, 1984, respectively). These fishes offer an opportunity to investigate otter prey selection on relatively complex prey communities (cf. Carss et al., 1998) as they form mixed‐species assemblages (Winfield & Nelson, 1991). However, Carss (1995) concluded that if studies of otter feeding ecology were to become more than mere lists of prey items, there was an urgent need to quantify current spraint analysis techniques and their associated errors more rigorously than before. This is undoubtedly true for studies which attempt to determine the species‐ and size‐composition of cyprinids in the diet of otters.
Polymorphism, mating preferences and sexual selection in the Arctic skua
Authors: Phillips R. A. , Furness R. W.
Published: February 2006

The intensive study of the Arctic skua (Stercorarius parasiticus) population on Fair Isle has provided an example of the maintenance of a stable polymorphism by sexual selection in conjunction with assortative mating (O'Donald, 1983). We tested several of O'Donald's hypotheses using data collected from the large colony of Arctic skuas on Foula. There was some evidence for assortative mating of the phenotypes but this did not confer any short‐term fitness advantage. In contrast to the situation on Fair Isle, we found little indication that sexual selection took place for dark males since no differences in timing of breeding or productivity were evident between the two male phenotypes in new partnerships. Nor could we detect variation in adult body size, body condition, or any life‐history characteristic between melanic and pale birds of either sex. Many of the selection pressures documented on Fair Isle appear to be absent at the neighbouring Foula, despite a fair degree of gene flow between these colonies. The frequency of pale adults on Foula and in Shetland as a whole has declined since the 1970s, indicating that currently directional selection may be favouring the melanic phenotypes at the southern end of the breeding range.
Maternal investment and factors affecting offspring size in polar bears (Ursus maritimus)
Authors: Derocher A. E. , Stirling I.
Published: February 2006

We examined data on live‐captured polar bears (Ursus maritimus) from western Hudson Bay relative to differential maternal investment and facultative sex ratio theory. In spring, shortly after den emergence, we found no differences in mass or body length of cubs in litters of one or two. In triplet litters captured in spring, male cubs were larger than females in both mass and body length, possibly due to sibling competition for limited maternal resources. In cubs captured during autumn, sex‐based differences in mass and body length were found only in litters of one with males larger than females. Yearling males captured in autumn were heavier and longer than females in litters of one and two. In twin litters of one male and one female cub in spring and autumn, we found no differences in mass or body length. Except singleton female cubs in spring and female and male triplets in spring, cub and yearling mass were correlated with maternal mass. Mothers with singletons in spring were more likely to have male cubs but, in general, there was little evidence to suggest that mass or age of mothers influenced offspring sex. Litter size, maternal mass, and maternal age all influenced cub and yearling size, but offspring sex was less important. Results suggest that female polar bears do not normally invest differentially between offspring of different sexes except in triplet litters in spring.
The male reproductive cycle of three species of Australian vespertilionid bat
Authors: Hosken D. J. , Blackberry M. A. , Stewart T. B. , Stucki A. F.
Published: February 2006

The male reproductive cycles of three species of vespertilionid bat (Nyctophilus geoffroyi, N. major and Vespadelus regulus) are described. Descriptions are based on the degree of testicular and cauda epididymal development estimated from field captures, and for N. geoffroyi, on histological examination of fixed specimens and assays of their testicular testosterone concentrations. All species were found to undergo a dissociated pattern of reproduction; the activity of the testes and accessory glands of reproduction were asynchronous. Spermatogenesis occurred in summer/early autumn (December–March) and testes generally regressed before mating began in autumn (March–May). Spermatozoa were stored in the cauda epididymides during the mating period. Leydig cells of N. geoffroyi involuted prior to mating but the prostate gland remained enlarged and secretory during winter (June–August), regressing in late spring (November). Testicular testosterone concentrations were greatest when Leydig cells were maximally enlarged, and concentrations were low during the mating period. The reproductive cycle of all species apparently involved asynchrony between primary and secondary sexual function, which is typical of vespertilionid bats inhabiting temperate latitudes. As mating occurs when sperm stores cannot be replenished, selection for prudent sperm allocation may be expected.
Effects of density and weather on survival of bighorn sheep lambs (Ovis canadensis)
Authors: Portier C. , Festa‐Bianchet M. , Gaillard J.‐M. , Jorgenson J. T. , Yoccoz N. G.
Published: February 2006

Density‐dependence in juvenile survival may be difficult to detect if survival is also affected by density‐independent factors. We investigated the relationships among weather parameters, population density, and lamb survival of bighorn sheep with long‐term data from a marked population where we manipulated population density. We distinguished neonatal survival and winter survival. Density interacted with weather variables to affect neonatal survival; spring and winter temperatures had a positive effect on neonatal survival only when population density was high. Neonatal survival was positively affected by spring precipitation independently of population density. Winter survival was positively correlated with temperature and precipitation during the previous spring, negatively correlated with density, and independent of winter temperature or snowfall. The effect of weather on lamb winter survival did not vary with density. Bighorn lambs are well adapted to harsh winter weather, but spring weather influenced survival of lambs at birth and during the subsequent winter, possibly through its effects on forage availability. Our study clearly demonstrates density‐dependence in lamb survival. Some of the effects of weather on lamb survival are density‐independent, others are mediated by an interaction with population density.
Optimal choice of foraging depth in divers
Authors: Mori Yoshihisa
Published: February 2006

When prey availability depends on water depth, a diver should choose an optimal depth for foraging. A model that predicts the optimal foraging depth for a diver is presented in this paper. General predictions derived from the model are: (1) optimal foraging depth is always shallower than the depth at which prey density is the highest, even if the depth of the highest prey density is within easy reach; (2) a larger diver should make deeper and longer dives and stay longer on the surface than smaller divers for optimal foraging; (3) foraging efficiency of larger divers is not always greater than smaller divers, although the larger divers forage at the depth of higher prey density. These predictions, derived from the model, are consistent with the comparative studies of diving behaviour in marine birds.
Deferred seasonal increase in testes weight under poor nutritional conditions in a sub‐Antarctic population of rabbits (Oryctolagus cuniculus)
Authors: Boussès P. , Chapuis J.‐L.
Published: February 2006

The annual cycle of testes weight of adult male rabbits (Oryctolagus cuniculus) was studied in three populations on the sub‐Antarctic Kerguelen archipelago during 1984–85. This study was completed in April 1987 with an analysis of differences in diet quality between populations, assessed by the proportion of nitrogen and lignin in stomach contents. A marked annual cycle of testes weight was observed in all populations, with a rapid fall in testes weight from February to March. As in most rabbit populations studied elsewhere, testes growth resumed immediately in two populations (called Morne and Molloy). In contrast, testes growth was deferred by five to six months in the third population (Armor), subject to harsher environmental conditions. Moreover, a larger proportion of the Armor males had inactive testes during the reproductive season. The diet of the Armor population was characterized by low nitrogen and high lignin content, suggesting poor‐quality diet as an immediate cause of deferred testes growth. We propose that reduced testes size during adverse conditions might be adaptive by increasing survival probability through reduction of basal metabolism and limitation of agonistic and reproductive activities, behaviours which are costly in terms of high energetic expenditure. However, at the population level, the timing of the breeding season was not related to the cycle of male testes weight and thus seems to depend on females' condition.
A new species of Prosorhochmus (Hoplonemertea, Monostilifera) from the Chafarinas Islands (western Mediterranean)
Authors: Frutos I. , Montalvo S. , Junoy J.
Published: February 2006

A viviparous hoplonemertean, Prosorhochmus chafarinensissp. nov., is described from the Chafarinas Islands (western Mediterranean). The species lives in the low eulittoral under the encrusting alga Lithophyllum lichenoides. Prosorhochmus chafarinensis is compared and contrasted in detail with the other valid members of the genus, P. claparedii from European waters, P. americanus from South Carolina, and P. adriatica from Italy.
The influence of molar occlusal surface area on the voluntary intake, digestion, chewing behaviour and diet selection of red deer (Cervus elaphus)
Authors: Pérez‐Barbería F. J. , Gordon I. J.
Published: February 2006

The loss of tooth effectiveness due to molar wear has been proposed as an important cause of mortality in ungulate populations. Voluntary intakes, digestibility, mean retention times, chewing behaviour (during eating and rumination), and diet selection (physical selection: short vs long particles in hay; and botanical selection: leaf vs stem) were compared in two groups of female red deer (Cervus elaphus) which differed in molar occlusal surface area, in order to test the hypothesis that behavioural and physiological mechanisms can be used to maintain assimilation efficiency in the presence of low functional tooth effectiveness. The group with lower values for first lower molar occlusal surface area (OSA) corrected for body weight had lower voluntary food intakes (P= 0.0126). The low OSA group had a greater number of chews per g DM of food ingested (P= 0.0167), a greater time spent chewing (P= 0.0476) but a lower number of chews per min than did those with a high OSA (P= 0.0484). The total number of chews per day was similar for both groups (P= 0.2011). The number of ruminating chews per day was less for the low OSA group (P= 0.0377). The group with low OSA values had a larger average particle size in their faeces (P= 0.0346). No differences were detected between groups in the physical or botanical composition of the diet selected (P= 0.3030, P= 0.3056, respectively) or in total digestibility and mean retention times (P= 0.1357, P= 0.3464, respectively). As a consequence of the lower voluntary intake the low OSA group had a lower digestible dry matter intake (P= 0.0170). This study supports the view that intake modification and the time invested in chewing during eating are the main mechanisms used to compensate for reduced chewing effectiveness associated with changes in tooth morphology, although the compensation is not total.
Morphological and genetic differentiation of Patella granularis (Gastropoda: Patellidae): recognition of two sibling species along the coast of southern Africa
Authors: Ridgway Tyrone M. , Stewart Barbara A. , Branch George M. , Hodgson Alan N.
Published: February 2006

Morphological and isozyme variations between 13 populations of the species hitherto named Patella granularis were investigated to see whether differences in shell structure between the west coast versus the south and east coasts of southern Africa are supported by other morphological features or by genetic differences. The shells showed a definite decrease in size from west to east, but this is correlated with productivity and is of no diagnostic use in distinguishing between populations. Discriminant functions analysis based on shell morphometrics failed to separate populations from the three coastal regions. Shells from the northern east coast do, however, have shell nodules with a dark pigmentation, distinctly separating them from those further south and west. No differences in radular or soft part morphology were detected between the populations, but the four northernmost populations on the east coast have a significantly shorter Z looping of the gut than the other populations along the coast. Significant microstructural differences in the sperm were also detected between these two groups of populations. Electrophoretic analysis of 16 enzyme loci failed to detect any significant differences between the west and south coast populations, but revealed a genetic identity (Nei) of 0.528 as well as four diagnostic alleles between the four northernmost populations from the east coast compared with those to the south and west. The two genetically distinct forms occurred sympatrically at one of the study sites on the east coast (Coffee Bay). It was concluded the two groupings were sufficiently different to warrant the recognition of a separate species, which is centred in KwaZulu‐Natal on the east coast and extends south to Coffee Bay, from where it is replaced by P. granularis. There is, however, no evidence at all that the west coast populations are in any way separable from the remaining populations of P. granularis on the south coast.
Variation in the onset of incubation in the pied flycatcher (Ficedula hypoleuca): fitness consequences and constraints
Authors: Potti Jaime
Published: February 2006

Reproductive correlates and fitness consequences (survival, recruitment) of variation in the incubation onset of pied flycatchers (Ficedula hypoleuca) were studied across 4 years in a southern European population, where between 36 and 89% of the females started to incubate with the penultimate egg or earlier. Females started to incubate up to 3 days before completing their clutches, this being accompanied by hatching spread. Females who advanced incubation before completing the clutch tended to be in better condition and to lay larger clutches than those that postponed incubation until the clutch was complete. Although laying date had no effect on onset of incubation, the effect of clutch size was much more marked when the influence of laying date on clutch size was controlled. Females who started to incubate earlier fledged more young than females delaying incubation but their higher fledgling success was unrelated to recruitment. Females starting to incubate with the last egg had fewer fledglings but of larger size, higher mass, and in better condition than females who advanced the incubation. Female survival to the next breeding season did not differ between those that started incubation before clutch completion and those that did not do so, but an advanced onset of incubation by females was related to higher mortality of their pair mates. Females that increased the size of the clutch with respect to the previous year tended to incubate their eggs earlier, while those whose clutch size did not change or was lower started incubation at about the same stage they did the year before. This trend was apparently influenced by improvements in body condition. Clutch size may constrain onset of incubation through environmental or genetic correlations, which are likely to be mediated by hormones. It is proposed that, in this population, an early onset of incubation in pied flycatchers does not affect reproductive fitness in most circumstances.
Spatial organization of mountain gazelles Gazella gazella reintroduced to central Arabia
Authors: Dunham Kevin M.
Published: February 2006

Captive‐born mountain gazelles (Gazella gazella), including 28 radio‐collared and 54 tagged animals, were freed in Hawtah Reserve, Saudi Arabia, during 1991–95. The size (as minimum‐area convex polygons) and spatial distribution of their individual ranges were determined from daytime radiotracking and sightings. Some adult males were territorial and territorial fidelity was >94%. Territories were maintained year‐round and were arranged linearly along the wadi floor. Initially, the size of territories decreased as their density increased, but after density stabilized, median territory area was 0.6 km2. The ranges of up to four released females were centred on each territory and female core areas were arranged in clusters along the wadi. Female ranges became smaller as the density of territories increased. After females had dispersed, their annual range averaged about 1 km2 during both 1993 and 1994 in wadis without domestic livestock and where, consequently, plant standing crop was high. Where camels foraged and plant standing crop was low, female ranges averaged 4.6 and 1.6 km2 during these two years. Some females shifted their core area, and their annual range was twice as large. The range area of non‐territorial males averaged 6.7 km2 and extensively overlapped the ranges of other bachelors. Bachelor males occasionally passed through territories, but some wadi sections were used often by bachelors and seldom by females. The size and spatial distribution of gazelle ranges did not change seasonally, despite the temporal variation in rainfall. Runoff concentrated in wadis and the consistent food supply there allowed gazelles to occupy small ranges, even though annual rainfall was low (<150 mm).
Feeding ecology of the neotropical river otter Lontra longicaudis in an Atlantic Forest stream, south‐eastern Brazil
Authors: Pardini Renata
Published: February 2006

The feeding habits of the neotropical river otter Lontra longicaudis were studied in a headwater stream of the Atlantic Forest, south‐eastern Brazil, for 17 months. The otters fed mainly on fish (93% of the scats), but invertebrates were also frequent items in the diet (78.9% of the scats), as observed for the same species in lentic habitats and for other species of Lontra as well. It is suggested that the high proportion of invertebrates in the diet in comparison to Lutra is related to differences in the dentition of the two genera. The observed seasonal variation in the diet of L. longicaudis was probably a result of fluctuations in the abundance of a main prey item, a megalopteran larva (Corydalus sp.). Prey selection, regarded as differences between rates of predation and relative abundance of food items, was demonstrated for the two most important groups of otter prey: fish and crustaceans. Although they are able to capture mobile prey, otters seem to prefer feeding on prey showing lower escape ability – among fish they select armoured catfish, and among crustaceans they select crabs.
The early life of Sepia officinalis, and the contrast with that of Octopus vulgaris (Cephalopoda)
Authors: Nixon Marion , Mangold Katharina
Published: February 2006

The egg and hatchling of Sepia officinalis L. is relatively large, compared with those of other cephalopods. We review the information on growth, chromatophores, behaviour, prey capture, colour and body patterns of this sepiid, for correlation with changes in morphology and development of its central nervous system. We compare the early life of S. officinalis with that of the common octopod, Octopus vulgaris, Cuvier 1797. Sepia officinalis is initially benthopelagic but subsequently is mostly benthic in habit. Octopus vulgaris enters the plankton immediately after hatching and spends several weeks there before it settles to a life spent mostly on the bottom.