bluuebunny/crossref_metadata_2025 huggingface dataset:
Clutch size for Mediterranean loggerhead turtles (Caretta caretta)
Authors: Hays G. C. , Speakman J. R.
Published: March 2009

We investigated the number of eggs laid and the total clutch volume for loggerhead turtles (Caretta caretta L.) nesting on the Greek island of Cephalonia (38° 09′ N, 20° 33′ E) during 1990. Both the number of eggs laid and clutch volume were positively related to female body size, and the mean explained variation for these relationships (36·6% and 37·7%, respectively) were not significantly different. Clutch volume decreased as the season progressed because individuals laid successively smaller clutches. The inter‐nesting interval (range 15–19 days) did not significantly influence the number of eggs laid or clutch volume. For individuals seen laying more than once, female size in combination with the number of a clutch in relation to all the clutches observed for that individual, together explained 65·5% of the variation in clutch volume.
Mitochondrial DNA variation and phylogenetic relationships of Jasus spp. (Decapoda: Palinuridae)
Authors: Brasher D. J. , Ovenden J. R. , White R. W. G.
Published: March 2009

The seven species of rock lobster in the genus Jasus have a fragmented circumpolar distribution, inhabiting continental or island waters of the Southern Ocean. Gene flow between nominal species is possible as the planktonic larval stages of Jasus are widely dispersed in major oceanic gyres. Restriction endonuclease analysis of mitochondrial DNA (mtDNA) from five species (J. verreauxi, J. novaehollandiae, J. edwardsii, J. lalandii and J. tristani) was used to assess taxa previously defined only by morphological criteria. Intraspecific mtDNA nucleotide sequence diversity was generally high (0˙33–0˙99%). An absence of episodic population bottlenecks and extinctions, attributable to a teleplanic (far wandering) and prolonged pelagic stage, may be a significant factor contributing to this variation. New Zealand (J. edwardsii) and Australian (J. novaehollandiae) populations appear to be conspecific and should be referred to as J. edwardsii; however, a significant difference in the magnitude of mean sequence diversities between these populations may indicate restrictions to gene flow across the Tasman Sea. The genome of J. verreauxi is highly distinct from the genomes of the other species (nucleotide sequence diversity: 14˙92–16˙67%), supporting the existence of ‘verreauxi’ and ‘lalandii’ groups within Jasus. High sequence diversities separating J. edwardsii, J. lalandii and J. tristani (4˙41–7˙36%) indicates longterm reproductive isolation. Hypotheses for the evolution of ‘lalandii’ group Jasus, which suggest a relatively recent divergence of J. lalandii and J. tristani, are not supported by phylogenetic reconstruction. Instead, it gives systematic validity to the grouping of J. lalandii with J. edwardsii as proposed by the existing taxonomy.
Ecological correlates of small mammal community structure in the semi‐arid Karoo, South Africa
Authors: Kerley Graham I. H.
Published: March 2009

The understanding of the determinants of small mammal community structure in arid and semiarid ecosystems is of importance, both in the light of the role that small mammals play, and the impact of livestock grazing on the flora of these systems. In a study aimed at identifying these determinants, small mammal assemblages and environmental features were quantified at six localities (a gradient of floristic structure, with constant annual rainfall) across the southern Karoo, South Africa. Stepwise variable regression indicated that small mammal diversity was correlated with plant and rock cover, as well as plant cover and horizontal foliage diversity at intermediate heights (40–60 cm). Initially, small mammal diversity increased with increasing plant cover, but decreased at cover levels greater than 30%. This relationship is similar to that found in other desert systems, although the peak in diversity found here is at higher levels of plant cover than found previously. I suggest that this higher peak may be owing to the lack of reliance on granivory by these animals, which are relatively omnivorous. This model may therefore explain the conflicting reports on the impact of livestock grazing on desert small mammals, with small mammal diversity decreasing with grazing below the peak, and increasing with grazing above the peak.
The effect of varying calcium intake on calcium metabolism in wild rodent species
Authors: Shore R. F. , Balment R. J. , Yalden D. W.
Published: March 2009

Calcium is essential for mammals but distributed heterogeneously in the environment and so the calcium content of the diet of wild small mammals can vary with habitat geology. The effect of varying the calcium intake of two wild rodent species, the granivorous wood mouse Apodemus sylvaticus and the herbivorous bank vole Clethrionomys glareolus, was investigated. Wood mice were similar to laboratory rodents in their calcium metabolism. Net calcium gut absorption efficiency was 11–15% in wood mice fed either high (0˙87%) or low (0˙30%) calcium diet. No more than the equivalent of 6% of the ingested calcium load was excreted in urine but this was sufficient to eliminate the equivalent of all the extra calcium absorbed across the gut when mice were fed the high calcium diet. In contrast, mean net calcium gut absorption efficiency in bank voles was high and increased from 28% to 42% when dietary calcium content was tripled. Urine was important for excreting calcium, the equivalent of up to 23% of intake being eliminated by this route. Despite this, bank voles fed the high calcium diet assimilated three times more calcium than voles fed the low calcium diet; this was in direct proportion to the three‐fold difference in dietary calcium concentration. Possible implications for wild rodents in calcium‐rich and calcium‐poor habitats are discussed.
Laboratory experiments on the effect of light and cover on the behaviour and growth of African catfish, Clarias gariepinus (Pisces: Clariidae)
Authors: Britz P. J. , Pienaar A. G.
Published: March 2009

The effect of different photoperiod regimes, as well as cover in continuous light (24L/0D) and darkness (OL/24D), on the growth rate of larval Clarias gariepinus was evaluated. In addition, a behavioural study of the effect of light on larval and juvenile C. gariepinus was made. The growth rate of larvae was found to increase with shorter light periods, the highest being recorded in continuous darkness (0L/24D photoperiod). Cover was found to enhance the growth rate of larvae reared under a continuous light period, however, the presence of cover did not affect the growth rates of larvae reared in continuous darkness. The behaviour of larval and juvenile catfish differed markedly in continuous light and darkness. When subject to a continuous light period, a strong negative phototaxis, long rest periods interspersed with disturbed activity, refuge seeking behaviour, and increasing incidence of territorial aggression were observed. In continuous darkness, the fish displayed a high level of active swimming with fewer rest periods, and a lower incidence of disturbed rest activity. The level of territorial aggression among fish in continuous darkness gradually declined and became negligible. Higher levels of browsing and airbreathing activity were observed in continuous darkness than in light. The present results, interpreted together with other ecological and anatomical data, demonstrate this species to be primarily a nocturnally active, tactile feeder, with a distinct diet activity pattern. The refuge seeking behaviour observed in the light is interpreted as an adaptation to avoid predators that rely on sight to detect prey. This behaviour, however, appears to promote intraspecific competition for refuges, resulting in a high degree of territorial aggression, and probably an increase in the rate of cannibalism. With regard to fish culture, it is suggested that the rearing of larvae in conditions of continuous darkness or low light intensity is optimal owing to the higher growth rates and apparent reduction of stress observed under these conditions.
Locomotion and bone strength of the white rhinoceros, Ceratotherium simum
Authors: Alexander R. McN. , Pond C. M.
Published: March 2009

Measurements have been made, of lengths and of geometric properties of cross‐sections, of the long bones of the legs of a young white rhinoceros of about 750 kg body mass. These are considered in conjunction with data from film of white rhinoceros trotting and galloping. The stresses developed in the bones in running are rather low, in comparison with other large mammals, suggesting that rhinoceros skeletons may be built to unusually high factors of safety. The long, relatively straight legs of elephants (whose bones experience higher stresses) are contrasted with the shorter, less straight legs of the other graviportal mammals.
Activity budget and foraging behaviour of red squirrels (Sciurus vulgaris) in coniferous and deciduous habitats
Authors: Wauters L. , Swinnen C. , Dhondt A. A.
Published: March 2009

Activity pattern, activity budget and foraging behaviour are compared between radiotagged squirrels in a coniferous and a deciduous habitat. Differences between habitats are explained in terms of differences in food availability, food choice and feeding rate.
Prolonged and daily torpor in the feathertail glider, Acrobates pygmaeus (Marsupialia: Acrobatidae)
Authors: Jones Caroline J. , Geiser Fritz
Published: March 2009

Deep and prolonged torpor in marsupials is only known from the pygmy possums, family Burramyidae. We investigated the pattern of torpor in the feathertail glider Acrobates pygmaeus (Acrobatidae) to determine whether members of other marsupial families also possess the ability of remaining torpid for several days with body temperatures (Tb) approaching 0°C. At high air temperatures (Ta) of 15 and 20°C, A. pygmaeus usually exhibited daily torpor. Torpor bouts at Ta 12°C usually lasted for about 2˙5 days and at Ta 8°C up to 5˙5 days. The metabolic rate during torpor was reduced to about 1% of that in normothermic, resting individuals. The Tb during torpor was regulated at about 2°C when Ta fell below about 0˙8 °C. Arousal from torpor was rapid and the mean fastest rewarming rate was 0˙88°C/min. While A. pygmaeus exhibited deep and prolonged torpor, its pattern differed somewhat from deep hibernation. Acrobates pygmaeus did not show prehibernation fattening and a subsequent prolonged hibernation period and it appears that prolonged torpor is used only in emergency situations.
The reproductive strategies of two Antarctic rotifers
Authors: Dartnall H. J. G.
Published: March 2009

The bdelloid rotifers Philodina gregaria Murray and Adineta grandis Murray were both cultured through three generations. The results suggested the following models for calculation purposes: (1) that individual Adineta grandis live for 40 days and, at death, give rise to five offspring; (2) that individual Philodina gregaria live for 89 days, producing 18 young at three‐day intervals, the first on day 36 and the last on day 87 (the animal dying two days later).

Mathematical expressions for population growth were formulated, from these models, and used to interpret the field observations obtained from a shallow pool on Signy Island (60°43′ S, 45°38′ W) during the course of an Antarctic summer.

Midway through the summer, two seals crawled through the pool and upset the continuity of the field study. This natural catastrophe not only provided an interesting insight into the recovery of such habitats but provided an opportunity to test further the hypotheses formulated in the culture experiments.
Prey‐capture techniques and prey preferences of Chrysilla, Natta and Siler, ant‐eating jumping spiders (Araneae, Salticidae) from Kenya and Sri Lanka
Authors: Jackson R. R. , Olphen A. Van
Published: March 2009

The predatory behaviour of Chrysilla lauta and Sliersemiglaucus from Sri Lanka, and four species of Natta from Kenya, was studied in the laboratory for the first time. These salticids eat ants, a prey most salticids avoid. These species' specialized behaviour for catching ants is described and compared to their behaviour for catching other insects. Three different types of tests of prey preference were carried out and, in each type, ants were taken in preference to other insects. Preference for ants, and prey‐specific predatory behaviour did not depend on prior experience with ants. Results from this study are discussed in relation to recent findings on other ant‐eating salticids.
Timing of births and juvenile mortality in the South American fur seal in Peru
Authors: Majluf Patricia
Published: March 2009

In most species, synchronous, seasonal reproduction is usually associated with higher offspring survival in animals giving birth around the peak, relative to those breeding at the extremes of the reproductive season. In contrast, in the South American fur seal (Arctocephalus australis) at Punta San Juan, Peru, females pupping around the peak of births had a greater probability of losing their pups and/or tended to lose them at an earlier age than females breeding early or late in the season. However, the timing of breeding in this population varies little between years and is consistently synchronous. Individual females maintained their relative breeding times in consecutive years, regardless of whether or not they lost their pup the previous year. Thus, pup mortality seems to have no effect on the timing of reproduction in this population.

High breeding densities and the consequent high pup mortality in the S. American fur seal in Peru may have resulted from intense poaching outside protected areas and are of recent origin. The reproductive synchrony in this population could have originally evolved as a response to seasonal variations in food availability and weather conditions, differences in female or pup body condition, predation pressure, sexual selection and/or harassment avoidance, but at the present high density levels has become maladaptive.
Estimation of oxygen‐diffusing capacity in the gills of different sizes of a tilapia, Oreochromis niloticus
Authors: Kisia S. M. , Hughes G. M.
Published: March 2009

Measurements on gills of features that affect gas exchange have been studied in relation to body weight in specimens (0.0112–812.3 g) of a tilapia, Oreochromis niloticus. The data were analysed with respect to body weight by means of logarithmic transformations (log Y= log a+b log W). The slopes (b) of the log/log regression lines for the gill area, harmonic mean diffusion distance and oxygen diffusing capacity were 0.777, 0.077 and 0.700, respectively. The gill respiratory area of O. niloticus (Trewavas) increases as the fish develops because the number and bilateral area of secondary lamellae increase. The scaling value for oxygen‐diffusing capacity is less than the value for gill area because of the slight increase in harmonic mean diffusion distance with development.
Different types of photophore in the oceanic squids Octopoteuthis and Taningia (Cephalopoda: Octopoteuthidae)
Authors: Herring P. J. , Dilly P. N. , Cope Celia
Published: March 2009

The oceanic squid Octopoteuthis danue Joubin has one type of photophore on the head, body and arms, but another type on the eight arm tips. The first type has acomplexcapillary network, with elastic walls and a thick reflector. The arm tip organs have no such capillary core but a dense matrix containing paracrystalline assemblies.

Taningia danae Joubin (the only other genus in the family Octopoteuthidae) has only two large arm tip photophores. These are similar in their general organization to the arm tip photophores of Octopoteuthis, but their detailed structure is quite different.

There has evidently been independent evolution of photophores in this family of squids.
The comparative energetics of rigid endothermy: the Arvicolidae
Authors: McNab Brian K.
Published: March 2009

Rate of metabolism and body temperature were examined in 24 species of arvicolid rodents, for 15 of which data are presented here, to determine the factors that influence their level of energy expenditure. Arvicolids are characterized by a high, precisely‐regulated body temperature, a high basal rate of metabolism by general mammalian standards, and a standard thermal conductance, except at large masses, when low conductances can occur. No evidence of entrance into torpor is known for any arvicolid; its absence is associated with especially high basal rates at masses smaller than 52 g. Arvicolids that live in cold climates, i.e. at high altitudes and latitudes, have higher basal rates than species that live in other environments. Basal rates, however, appear to be independent of food habits, presumably because of the small mass of most species and possibly because all species are herbivorous. A small size in combination with herbivory has permitted arvicolids to maintain continuous endothermy, which in turn has permitted them to exploit cool‐to‐cold environments by means of a high rate of production. The use of daily or seasonal torpor might well have prevented arvicolids from attaining the pivotal position in energy transfer that they presently occupy in many high‐latitude communities.
Egg development in the octopus Eledone cirrhosa
Authors: Boyle P. R. , Chevis D.
Published: March 2009

The development of egg/follieular cell complexes is described in maturing females of the octopus Eledone cirrhosa. Follicle cells proliferate to enclose the oocyte in a single epithelial layer which becomes deeply infolded. Active cell division of the follicle cells and recruitment of cells from an outer (thecal) layer generate this expansion of follicle cell epithelium. The onset of the main phase of vitellogenesis, secretion of protein yolk, occurs when eggs reach about 2 mm in length and is marked by the columnar appearance of the follicle cells and an increased number of larger and more complex nuclei. A significant proportion of the egg population fails to develop beyond 2–3 mm in length and these eggs subsequently degenerate.
The effect of egg mass on the growth and survival of blackbirds: a field experiment
Authors: Magrath Robert D.
Published: March 2009

A number of studies on birds have shown a positive correlation between egg mass and the growth (or survival) of chicks. However, a correlation based on non‐experimental data does not demonstrate that egg mass affects growth, because it could be confounded by parental or territory quality. One way to see if pre‐hatching attributes affect growth or survival is to swap hatchlings between nests, so that parental or territory quality do not confound correlations. I conducted such a fostering experiment on the blackbird, Turdus merula. Apart from very light eggs, that did not hatch, egg mass did not affect hatching success. Heavier eggs produced both heavier and larger nestlings. Nestlings raised by their own parents showed a positive correlation between hatchling mass and mass and size both early (day‐4) and late (day‐8) in the nestling period. The mass and size of fostered nestlings correlated with the mean mass of their natural parents' hatchlings, with higher coefficients early rather than late in the nestling period. By contrast, early in the nestling period there were no significant correlations of nestling mass or size and mean hatchling mass of the foster parents, but there were significant correlations late in the nestling period. Thus pre‐hatching attributes of the egg do affect nestling size but environmental effects, including parental or territory quality, have an affect late in the nestling period. Direct manipulations of components of egg mass are required before one can conclude that egg mass affects growth, rather than some correlated pre‐hatching attribute. There was no clear effect of egg mass on the probability that a hatching bird would survive until two weeks after fledging (shortly before nutritional independence), despite the fact that nestling mass does correlate with fledgling survival. I suggest that egg mass affects the ‘size’ component of mass and that juvenile survival depends on the ‘condition’ component of mass.
Cyathostoma lari (Nematoda) infection in birds of prey
Authors: Simpson V. R. , Harris Eileen A.
Published: March 2009

Cyathostoma lari Blanchard, 1849 is a nematode which parasitizes the orbital and nasal cavities of gulls (Laridae), the crow family (Corvidae) and occasionally other species of birds. It has not, apparently, been reported in birds of prey, although two other species, C. americana and C. brodskii, have been recorded in the air sacs of raptors in North America and the USSR.

This report describes infection by nematodes, provisionally identified as C. lari, in the orbital cavities of two kestrels (Falco unnunculus) and a common buzzard (Buteo buteo). A single specimen was also recorded in the lower eyelid of a sparrowhawk (Accipiter nisus). There was no evidence of pathogenicity in the kestrels and buzzard, but in the sparrowhawk the parasite was possibly associated with damage to the eyelid.
Phylogenetic relationships of the fox‐like canids: mitochondrial DNA restriction fragment, site and cytochrome b sequence analyses
Authors: Geffen E. , Mercure A. , Girman D. J. , Macdonald D. W. , Wayne R. K.
Published: March 2009

The fox‐like canids include taxa from the genera Alopex, Otocyon, Fennecus, Urocyon and Vulpes. Previous morphological analysis indicated that species from the latter three genera are very similar and should be included in the same genus whereas Alopex and Otocyon are sufficiently different to be included in separate genera. Using phylogenetic methods, we analyse mitochondrial DNA (mtDNA) restriction fragment and restriction site data, and 402 bp of cytochrome b sequence variation in fox‐like canids. Our results suggest that Alopex lagopus, the arctic fox, is actually a very close relative of the swift fox, a species in the genus Vulpes. Similarly, the fennec, Fennecus zerda is related to the co‐existing desert species, the Blanford's fox, Vulpes cana. The grey fox, Urocyon cinereoargenteus, and the bat‐eared fox, Otocyon megalotis, are not closely related to each other or to any of the sampled fox taxa. Our results indicate that desert adaptations have evolved independently at least twice in the Canidae, and that Pleistocene glaciations and character divergence may be important causes of morphological change in canids.
Body size, age and reproduction in the leopard toad, Bufo pardalis
Authors: Cherry M. I. , Francillon‐Vieillot Hélène
Published: March 2009

Data on the relationships between body size and age were obtained for a sample of leopard toads Bufo pardalis from a breeding population of this species from the Cape Peninsula, South Africa. Age was determined by counting the number of lines of arrested growth in histological sections of a digit clipped from each individual. In males there was a positive, but weak, correlation (explaining only 18% of the variance) between body size and age, and in females no correlation at all existed between these two variables. Males which were successful in obtaining matings were not older than unsuccessful males. Age of males at the breeding site ranged from one to three years, whereas females ranged from two to six years old. This represents both the earliest age of reproduction, as well as the greatest difference in longevity between the sexes, documented for an anuran species.
Megalopae and early postlarval stages of East African Percnon (Decapoda: Brachyura: Grapsidae)
Authors: Hartnoll Richard G.
Published: March 2009

The megalopae and first crab instars are described for three of the four Indo‐west Pacific species of the grapsid crab Percnon—P. abbreviatum, P. guinotae and P. planissimum. Keys are provided to these three species and for the Atlantic/East Pacific P. gibbesi. The validity of separating P. planissimum and P. gibbesi is discussed, as are the implications of the unusually large megalopa in Percnon.
Activity patterns of pipistrelle bats (Pipistrellus pipistrellus) in Oxfordshire
Authors: Maier Celia
Published: March 2009

A maternity colony of pipistrelle bats (Pipisfrellus pipistrellus), in Oxfordshire, was monitored between 1 March 1989 and 6 October 1989. An infra‐red ‘automatic bat counter’ was installed at the roost, to record the number of bats entering and leaving each minute throughout the night. Air temperature, light intensity at sunset, cloud cover, wind speed and rain were recorded on each night of monitoring. Insect abundance was estimated on 18 nights.

The nightly activity pattern was found to be unimodal in pregnancy, bimodal during lactation and unimodal post‐weaning. The mean time that each bat spent outside the roost ranged from 103–483 min, with a mean of 321 min.

Ambient air temperature and length of night were significant factors affecting mean time spent outside the roost. The percentage of the night which the bats spent away from the roost ranged from 22 to 88%, with a mean of 64%. There was a significant positive correlation between ambient air temperature and percentage of the night spent away from the roost. Insect abundance showed no significant correlation with the time that bats spent outside the roost. Wind and rain had no apparent effect on time spent outside the roost.
The ecology of three communities of small mammals at different altitudes in Malawi, Central Africa
Authors: Happold D. C. D. , Happold M.
Published: March 2009

This study compares the results of three studies and assesses the effects of seasonal changes in the environment on populations of small mammals at three altitudes in Malawi (Zomba Plateau [1900 m], Liwonde National Park [550 m] and Lengwe National Park [100 m]). Zomba Plateau had a higher annual rainfall (mean 2244 mm), longer wet season, shorter dry season, cooler temperatures and smaller water deficit than either Liwonde NP or Lengwe NP (which had similar climates). Maximum grass biomass (and fluctuation index) was 814 g/m2 (1.7) on Zomba Plateau, 1066 g/m2 (2.7) at Liwonde, and 854 g/m2 (30.5) at Lengwe. Sixteen species of rodents were recorded, 7–9 at each study area; the species on Zomba Plateau did not occur at the lower altitudes, and the lower altitude species did not occur on Zomba Plateau. Percentage Similarity and Coefficients of Community showed that there was considerable similarity between Liwonde and Lengwe, but no similarity between either of them and Zomba Plateau. Mean population densities of small rodents (range, fluctuation index) were 23/ha (15–35, 2.3) on Zomba Plateau, 12.6 (2.7–19.1, 7.1) at Liwonde, and 14.5 (0.9–30.9, 33.9) at Lengwe. Stability of the environment tends to confer stability in demographic characteristics. Reproduction was mainly confined to the wet season (December to April) at all altitudes. Comparison of the proportion of new individuals each month, and the duration of residence by individuals, suggests that turnover of the population was slowest on Zomba Plateau and fastest at Lengwe. There was no evidence for reduced litter size, reduced opportunity for reproduction, or increased age to maturity at the highest altitude compared with the lower altitudes as has been recorded in temperate environments.
The testicular cycle of Gambusia affinis holbrooki (Teleostei: Poeciliidae)
Authors: Fraile B. , Sáez F. J. , Vicentini C. A. , Miguel M. P. de , Paniagua R.
Published: March 2009

Fifteen male mosquito fish (Gambusia affinis holbrooki) were collected in 1989 on the 15th of each month to perform a quantitative histologic study of the annual testicular cycle including a calculation of the gonadosomatic index, testicular volume, and the total volume per testis occupied by each germ cell type. The cycle comprises two periods: spermatogenesis and quiescence. The spermatogenic period begins in April with the development of primary spermatogonia into secondary spermatogonia, spermatocytes and round spermatids. In May, the first spermatogenic wave is completed and the testicular volume begins to increase up to June when the maximum testicular volume and gonadosomatic index are reached. Germ cell proliferation with successive spermatogenetic waves continues until August. In September germ cell proliferation ceases and neither secondary spermatogonia nor spermatocytes are observed. However, spermiogenesis continues until October. In November, spermiogenesis has stopped and the testis enters the quiescent period up to April. During this period only primary spermatogonia and spermatozoa are present in the testis. In addition, a few spermatids whose spermiogenesis was arrested in November are observed. Testicular release of spermatozoa is continuous during the entire spermatogenesis period. The spermatozoa formed at the end of this period (September‐October) remain in the testis during the quiescent period and are released at the beginning of the next spermatogenesis period in April. Developed Leydig cells appear all year long in the testicular interstitium, mainly around both efferent ducts and the testicular tubule sections showing S4 spermatids.
The mating system and male mating success of the Virginia opossum (Didelphis virginiana) in Florida
Authors: Ryser Jan
Published: March 2009

The mating system of the Virginia opossum, a solitary, nocturnal marsupial, was studied over a period of two years in north–central Florida. There were two mating seasons each year, both lasting about four weeks and starting in mid‐January and late April, respectively. Radio‐tracking males and females revealed that, independent of body size, males doubled their home ranges during these periods to include an average of 5.9 females within their new ranges. Females were visited regularly and, on the night of oestrus, males directly competed for access to the female. Dominance and hence mating success was strongly related to body mass but not age. Dominant males weighed on average 3.18 kg (N = 20) compared to 2.65 kg of unsuccessful males. The largest of the competing males was successful in 20 of 23 cases involving at least two competitors. Individual male mating success varied from zero to three matings during a breeding season, but the range was probably underestimated. Mate searching activities were costly, as most males lost weight during both mating seasons. Weight changes were a function of body mass, with males over 2.2 kg losing up to 23% in weight and smaller males gaining weight. There was also evidence that male breeding activities entailed a survival cost.
The period of sexual maturation and the age at mating in Iridomyrmex humilis, an ant with intranidal mating
Authors: Passera L. , Keller L.
Published: March 2009

The process of sexual maturation was studied in the ant Iridomyrmex humilis. Spermatogenesis starts during the pupal stage and sperm is transferred to the seminal vesicles during the first four days after emergence. The testes start to degenerate early in the pupal stage and totally shrivel up during the first days after emergence. Males therefore have a fixed amount of sperm. Both males and females reach sexual maturity only 2–3 days after emergence; some of them mate as early as the first day after emergence. Overall, it appears that the length of time needed to reach sexual maturity in ants is highly correlated with the mode of colony founding. The maturation period is much longer in those species in which young queens initiate colonies without the help of workers (independent founding) than in those where young queens need the help of workers (dependent founding). This is probably associated with the fact that independent founding queens require large amounts of energy reserves in order to found colonies; these energy reserves are accumulated after emergence. In contrast, dependent founding queens do not accumulate as many energy reserves and are therefore sexually receptive at a younger age.
Water flux and mass gain during lactation in free‐living ringed seal (Phoca hispida) pups
Authors: Lydersen C. , Hammill M. O. , Ryg M. S.
Published: March 2009

Three ringed seal (Phoca hispida) pups were used to calculate water flux and milk intake, based on mass increase and dilution of injected tritiated water. Biological half life of tritium in ringed seal pups was 130 ± 17 h (mean ± S.D.). The plateau level of the isotope indicating equilibrium with the body water was, in all cases (N = 8), reached before the first blood sample was collected after 0·5 h. Daily water flux in the pups was 62·9 ± 21·5 ml kg‐1. Estimated daily milk intake of 1103 ± 388 ml milk resulted in a mass increase of 386 ± 104 g. Neonates had a fat content of 4·75%, and a water content of 70·1% (N = 3). Corresponding figures for a pup close to weaning were 36·5% and 46·3%. Isotope dilution calculations of body water gave an overestimate of 1·6% compared with body water content from desiccation. Ringed seal milk was found to contain 38·1% fat, 9·9% protein, 2·3% lactose and 1% ash.
Stridulatory behaviour in a New Zealand weta, Hemideina crassidens
Authors: Field L. H. , Rind F. C.
Published: March 2009

Using a femoral‐abdominal stridulatory mechanism, wetas produce the following stridulatory behaviours: aggression, mating, calling, defence and disturbance. Syllable period, rather than number of syllables/echeme or syllable duration, was the most stereotyped temporal parameter for aggression, mating and calling stridulation. Coefficients of variation of the above parameters were large and overlapped considerably for aggression and mating stridulation. We concluded that, for these two behaviours, a basic sound pattern is used to convey different messages to female and male receiver wetas, respectively, but the syllable period of the pattern decreases with increased excitation of males in aggressive encounters. In adult male combat, winners stridulated last in a bout, and produced significantly more aggression sounds than losers.
Functional analysis of the feeding apparatus and digestive tract anatomy of the aardwolf Proteles cristatus
Authors: Anderson M. D. , Richardson P. R. K. , Woodall P. F.
Published: March 2009

The aardwolf is unique amongst the myrmecophagous mammals in that it feeds almost exclusively on one genus of termite, Trinervitermes, yet it possesses none of the obvious external physical features (elongated snout, powerful limbs and claws) characteristic of this feeding style. Externally it looks simply like a diminutive hyaena. Behaviourally the aardwolf differs from the other typical ‘anteaters’, in that it does not dig for its prey, but licks them off the soil surface. Nevertheless, the aardwolf does have a number of anatomical features which are clearly adaptations to this diet. The most obvious of these are a broad spatulate tongue covered with large, hardened papillae, a broad palate, large mandibular salivary glands, and a muscular pyloric region in the stomach. A relatively short small intestine facilitates the rapid processing of large volumes of termites, while a distensible large intestine allows for the accumulation of faecal material. Some of these features associated with feeding and digestion are compared with those of the domestic dog Canis familiaris, the bat‐eared fox Otocyon megalotis and the black‐backed jackal Canis mesomelas.
The structure of the mandibular corpus and its relationship to feeding behaviours in extant carnivorans
Authors: Biknevicius A. R. , Ruff C. B.
Published: March 2009

Assuming some optimization of bone structure to applied mechanical loadings in vivo, different killing and feeding behaviours in carnivores should be reflected in observed differences in cross‐sectional shape of their mandibular corpora. Section moduli are used to gauge the magnitudes of bending moments in the mandibular corpus and, when dentary length is controlled, the magnitudes of forces applied to the corpus. Comparisons are made of section moduli at the P3P4 and P4M1 interdental gaps among canids, felids and hyaenids; in canids only, the M1M2 interdental gap was also studied. Local variations in loadings are identified by comparing the section moduli at adjacent loci along the corpus within each family.

The findings of this study show that the precarnassial corpora of canids and hyaenids have greater strength in bending than the corpora of felids of similar body weight. This is taken to reflect relatively greater bending moments under loading in the corpora of canids and hyaenids due, in part, to their elongate dentaries (relative to body weight). Relative to dentary length, however, the precarnassial corpora of felids and hyaenids have much greater strength in bending than the corpora of canids. These scaling relationships appear to reflect the high customary forces (i.e. not moments) applied to the precarnassial corpora of felids and hyaenids with sustained canine killing bites and with bone ingestion using the premolars, respectively. An increase in bending strength of the corpus caudal to the camassial blade in canids is interpreted to be an adaptation for bone‐crushing with the postcarnassial molars.
Seasonal and sex differences in the structure and chemical composition of adipose tissue in wild polar bears (Ursus maritimus)
Authors: Ramsay Malcolm A. , Mattacks Christine A. , Pond Caroline M.
Published: March 2009

Biopsy samples of adipose tissue from the upper thigh were collected in spring and in late summer/autumn from 370 wild polar bears (Ursus maritimus), including adult females with and without cubs, adult males and juveniles. Mean adipocyte volume was measured from all samples and chemical assays of the lipid, total protein and collagen were also performed on samples from 53 bears. Mean adipocyte volume was smaller in all specimens in spring than in late summer/autumn, but the differences were greatest for solitary adult females. The range of adipocyte volumes was much greater for adult females than for adult males, and in females only, mean adipocyte volume correlated significantly with total body mass. Therefore, adipocyte volume measurements from biopsy samples provide some information about fatness in adult females, but are worthless as an indicator of body composition in males and juveniles. In juveniles and females, but not adult males, the lipid content of the adipose tissue was up to 18% lower in autumn than in spring. The collagen content was significantly higher in autumn than in spring in all bears except females with cubs. We suggest that these differences in chemical composition arise from accumulation of water within and between the adipocytes, which would minimize tissue shrinkage, and from changes in the vascularization of the adipose tissue. These properties may be adaptations to rapid fattening and prolonged fasting and the sex differences may reflect the contrasting reproductive strategy of female and male polar bears.
Moult energetics of the northern elephant seal (Mirounga angustirostris)
Authors: Worthy G. A. J. , Morris P. A. , Costa D. P. , Boeuf B. J. Le
Published: March 2009

Northern elephant seals, Mirounga angustirostris, undergo an annual moult during which they shed all of their pelage and underlying epidermis. Moulting takes place on land and lasts a mean of 32.0±6.6 days. During this time the mean mass loss of adult females was 24.7±6.1%. Mean body composition at arrival (25.6±4.8%fat) did not differ significantly from that at departure (24.9±3.2%fat). Fat catabolism accounted for 93.6%of derived energy and 41%of mass lost. Approximately 3.5%of total mass loss was associated with the shedding of the pelage and epidermis. Moulting female northern elephant seals express an average daily metabolic rate of 2.0±0.6 times that predicted for adult terrestrial mammals. This energy demand was met by losing 3.0 kg d‐1 of total body mass. These energy expenditures suggest that, similar to data for harbour seals, the moult period is a time of relatively low energy expenditure.
Deep‐sea cephalopods of the north‐western Mediterranean: indications of up‐slope ontogenetic migration in two bathybenthic species
Authors: Villanueva Roger
Published: March 2009

The cephalopod fauna collected during six surveys carried out in the bathyal basin of the north‐western Mediterranean is discussed. Samples were taken at depths mainly between 1000 and 2000 m. Ten species were identified. Bathypolypus sponsalis and Neorossia caroli were the commonest species. Small individuals of both these species occurred at greater depths than did larger individuals, suggesting up‐slope ontogenetic migration. The depth ranges recorded for all species collected are discussed and compared to the results of previous studies found in the literature.
Egg size, first instar behaviour and the ecology of Lepidoptera
Authors: Reavey Duncan
Published: March 2009

There is striking variation in egg size among Lepidoptera. Part of the explanation could be a link between egg size and larval feeding ecology.

The relationship between absolute egg size and aspects of feeding ecology for different Lepidoptera families from different temperate regions is examined. Species that overwinter in the egg stage have larger eggs. There are significant differences in egg size with respect to feeding specificity but different families show different patterns. Woody plant feeders have larger eggs than herb feeders. There is little effect of proximity of the egg to the plant part that is eaten.

Patterns in the behaviour and survival of newly hatched larvae of 42 spp. of British Lepidoptera and their relationship to egg and larval size and to food plant characteristics are examined. Patterns in egg size with respect to feeding ecology are similar to those described above. There is a strong correlation between egg size and the size of newly hatched larvae. Newly hatched larvae survived for a mean of 1–20 days without food. Survival is not correlated with larval weight. Grass feeders survive longer than herb and woody plant feeders; the species surviving the longest feeds on lichens. Newly hatched larvae moved at a mean speed of 0.7‐267.8 cm h‐1. Speed is not correlated with larval weight or survival time. Grass feeders move faster than woody plant feeders which, in turn, move faster than herb feeders. Woody plant feeders tend to move upwards, grass feeders downwards and herb feeders both upwards and downwards. The proportion of larvae silking is negatively correlated with larval weight.

The strong links between egg size and larval feeding ecology and between feeding ecology and larval behaviour are discussed. It is surprising that larval body size does not appear to constrain the speed of movement, nor tolerance to starvation.
Poikilothermic traits and thermoregulation in the Afrotropical social subterranean Mashona mole‐rat (Cryptomys hottentotus darlingi) (Rodentia: Bathyergidae)
Authors: Bennett N. C. , Jarvis J. U. M. , Cotterili F. P. D.
Published: March 2009

When acclaimated for two months at 26 C the social Mashona mole‐rat Cryptomys hottentotus darlingi (±S.D.) resting metabolic rate (RMR) of 0·98±0.·14cm2O2g ‐1 h‐1 (n=21), within a thermal neutral zone (TNZ) of 28 31·5 C ambient temperature (Ta). The body temperature (Tb) of the mole‐rat is very low. 33·3±0·5 C, and remained stable between 25 31·5 C (n=28). Above 33 C. Tb increased to a mean of 34·±0· C (n=28) (Ta range 33 39 C). Below Ta 25 C. Tb showed strong poikilothermic tendencies, with Tb dropping to a mean of 26·8±1·16 C. whereas above Ta25 C. Tb varied in a typically endothermic pattern. The conductance is high 0·19±0·03 cm2 O2g1 C 1 (n=28) at the lower limit of thermoneutrality. The mean RMR at 18 C (the lowest Ta tested) was 2·63 ± 0·55 cm3 O2g 1 h 1 (n=7) which is 2·6 times that of the resting metabolic rate in the TNZ.
Morphology of the antennary gland exit duct in ecological and phylogenetic series of talitroid Amphipoda (Crustacea)
Authors: Moore P. G. , Morritt D. , Stevenson T. D. I.
Published: March 2009

The form of the proximal segments of antenna two peduncle and of the antennary gland exit duct on peduncle article two has been examined in 16 species of amphipod crustaceans (including 14 species of Talitridae). Gammarus duebeni(Gammaridae), regarded as exemplifying the norm for aquatic amphipods, has a very distinctive fluted exit duct emanating from a pronounced gland cone. The talitroid Hyale nilssoni was regarded as a typical representative of the hyalid‐like ancestors of the Talitridae. It also has a gland cone, but the exit duct of the antennary gland is a thin‐walled, collapsible cone. The two proximal articles of antenna two peduncle are much reduced in Talitridae. Only the second may retain a degree of mobility. No gland cone remains. The structure of the urinary exit duct in seven species of simplidactylate landhoppers (Bousfield's Gp IVa) was very similar to the hyalid condition. Beachfleas (Gp II) have strengthened, often sculpted ducts. whilst sandhoppers (Gp III) have no protruding exit duct at all. Only one species of Gp IVb (cuspidactylate) landhopper (Tasmanorchestia sp.) was investigated and it has an exit duct similar in form to that of the beachfleas (Gp II). Neorchestia plicibranchiata (a Gp IVa species), however, already known to be an anomalous species, has unusually elongate urinary ducts (for a Gp IVa species). These observations lend support to the notion that the landhoppers are a polyphyletic grouping and that the sandhoppers are a very isolated ecomorphological grouping within the family.
Mating system correlates of tarsal spurs in the Phasianidae
Authors: Sullivan M. S. , Hillgarth Nigella
Published: March 2009

Two methods for the analysis of cross‐species data are used to investigate whether tarsal spur length or number are correlated with mating system in three phasianid subfamilies. One method, the phylogenetic regression. suggests that polygamous species have relatively longer and fewer spurs than monogamous species. hut this relationship is not found when a matched‐pairwise comparison is used. These ambiguous results suggest that at the moment it is not possible to conclude either way whether spurs are under any selective pressure related to mating system, and that previously published conclusions are not supported.
Utilization, diet and diet selection by brent geese Branta bernicla bernicla on salt‐marshes in Norfolk
Authors: Summers Ron W. , Stansfield Julia , Perry Sue , Atkins Clare , Bishop Julie
Published: March 2009

The diet and utilization by brent geese of two plant communities (Limonium/Armeria marsh—a short sward community in the upper mid salt‐marsh and composed of several species, and Salicornia marsh—a community of the lower salt‐marsh dominated by Salicornia europuea agg. and Aster tripolium) were studied on the north Norfolk coast. The biomass on these communities was highest in autumn and declined markedly in November owing to the senescence and die‐off of the succulent species. This decline was not significantly precipitated by the grazing of the geese but coincided with their switch to inland habitats where the biomass m‐2 and total food available on fields of winter wheat and grassland within the population's home range was 20–30 times greater. Brent geese continued to graze salt‐marsh at a low intensity through the winter, feeding largely on Puccinellia maritima. In spring they returned largely to Limonium/Armeria marsh where they significantly reduced the regrowth of Puccinellia maritima.

The main plant species ealen was Puccinellia maritima, especially in mid winter. Salicornia maritima agg. leaves and seeds formed much of the diet in autumn, whereas Triglochin maritima, Plantago maritima and Aster tripolium were important foods on Limonium/Armeria marsh in spring. All these species were selected at some part of the year. Selection was related to the proline (an imino acid used by salt‐marsh plants as an osmoregulator) and chloride content and avoidance related to tannins. Two species which contained condensed tannins. Limonium vulgare and Armeria maritima, were rarely eaten. As well as being a nutrient, proline may help to neutralize the effects of tannins in the diet if incorporated into proline‐rich proteins.