bluuebunny/crossref_metadata_2025 huggingface dataset:
Habitat use and foraging behaviour of urban merlins(Falco columbarius)in winter
Authors: Warkentin I. G. , Oliphant L. W.
Published: March 2009

Habitat use and foraging behaviour of resident merlins(Falco columbarius)wintering in Saskatoon, Canada, were studied over a five‐year period. Birds were trapped through the winter and selected individuals fitted with radio transmitters to monitor continously their location, movements and activities from roost departure until re‐entry. Merlins maintained individual home ranges in winter, with extensive overlap between neighbouring birds in some cases. Yearling home ranges were not significantly different in size from those of adults. The winter home ranges of adults were closely associated with their previous nest site. Both adults and yearlings made significantly greater use of Residential habitat in the city than expected based on the area available in their home ranges. However, while adults remained largely in the two oldest habitat types, yearlings were also found in more recently built areas of the city. Home ranges held within the city were sometimes combined with foraging areas in the adjacent countryside. The use of foraging areas in farmyards and cattle feedlots outside of the city was most notable in adults, although some yearlings apparently learned this strategy in their first year. Merlins also used Commercial‐Industrial habitat for hunting at levels much higher than expected from its availability in their home ranges. Diets in summer and winter had a high degree of overlap; house sparrows(Passer domesticus)and bohemian waxwings(Bombycilla garrulus)made up a large proportion of the diet during both seasons. Hunting activity peaked at 09:00 and 16:00 h, reflecting the replenishment of energy stores lost over‐night, and the storage of energy in preparation for the next over‐night fast.
Sexual differentiation in the grey short‐tailed opossum, Monodelphis domestica, and the effect of oestradiol benzoate on development in the male
Authors: Moore H. D. M. , Thurstan S. M.
Published: March 2009

Observations were made of the early differentiation of the gonad in the grey short‐tailed opossum, Monodelphis domestica, using light and electron microscopy. An investigation was made also of the effects of neonatal treatment with oestradiol benzoate on sexual differentiation.

Neonates were removed from the nipple at various times after birth (0‐14 days), killed and karyotyped to determine the genetic sex. Some individuals were then fixed in buffered formalin, embedded in paraffin and prepared for light microscopy. Alternatively the mesonephri and gonadal anlagen were dissected free of tissue, fixed in buffered 2.5% glutaraldehyde and prepared for electron microscopy. Twenty‐two offspring from nine litters were examined.

At birth, pups were sexually undifferentiated and had rudimentary indifferent gonadal anlagen. By three days after birth, the gonad rudiments of males exhibited the first formation of sex cords with the coalescing of presumptive Sertoli cells. The sex cords of males were well defined by six days. By contrast, the gonads of female pups failed to display defined sex cords up to two weeks after birth.

An unusual feature was the initial appearance of a scrotal bulge in males as early as two days after birth, thus preceding any obvious morphological gonadal differentiation.

In all 34 pups were coated with oestradiol (1‐2 μg per application) for various lengths of time. Some individuals were allowed to reach maturity so that growth rate and sexual behaviour could be studied.

Oestradiol treatment had a profound effect on male neonates, but no apparent effect on female neonates. Testis development was inhibited with the failure of the rudimentary gonad to form sex cords. With the exception of near‐normal scrotum development, external and internal genitalia were completely feminized. Treated males allowed to reach maturity had growth rates similar to control females and exhibited oestrous behaviour in the presence of a control male.

The results suggest that gonadal differentiation in marsupials can be profoundly influenced by exogenous hormone. The early development of a scrotal bulge, preceding morphological differentiation, and the lack of an effect of oestradiol on scrotal formation would indicate that the differentiation of this somatic tissue may not be dependent on gonadal determination.
The dentition of fallow deer (Dama dama): a scoring scheme to assess age from wear of the permanent molariform teeth
Authors: Brown W. A. B. , Chapman Norma G.
Published: March 2009

The sequence of tooth wear was determined from skulls of fallow deer of known age. A system for scoring molariform tooth wear has been devised so that small but readily recognizable wear changes of the individual cusps may be recorded and used to assess the age of animals of unknown birth dates. The technique can be readily adapted for other ruminant species with the appropriate database.
Observations on genetic diversity of Bulinus cernicus (Gastropoda: Planorbidae) from Mauritius
Authors: Rollinson D. , Kane R. A. , Warlow A. , Southgate V. R. , Gopaul A. R.
Published: March 2009

Enzyme variation has been investigated in eight populations of Bulinus cernicus from Mauritius using isoelectric focusing and starch gel electrophoresis. Of 11 loci examined for 10 enzyme systems, seven were found to be polymorphic. These were malate dehydrogenase, glucose phosphate isomerase, acid phosphatase (A and B), 3‐hydroxybutyrate dehydrogenase, 6‐phosphogluconate dehydrogenase and NADH‐dependent diaphorase. Invariant loci were phosphoglucomutase, xanthine oxidase, fructokinase and αaL‐glycerophosphate dehydrogenase. The percentage of polymorphic loci within the populations ranged from 9.1% to 54.5%. The average heterozygosity per population for all loci ranged from 0,009 to 0.203. Genetic distance values ranged from 0.01 to 0.3 with the higher values associated with comparisons of populations from the north‐west and south‐east of the island. A comparison of data sets for 1980 and 1986 revealed the allelic frequencies at five enzyme loci to be remarkably consistent.
Metamorphosis of the feeding mechanism in tiger salamanders (Ambystoma tigrinum): the ontogeny of cranial muscle mass
Authors: Lauder G. V. , Reilly S. M.
Published: March 2009

Most previous research on metamorphosis of the musculoskeletal system in vertebrates has focused on the transformation of the skeleton. In this paper we focus on the transformation of the muscles of the head during metamorphosis in tiger salamanders (Ambystoma tigrinum) in order (1) to provide new data on changes in myology during ontogeny, and (2) to aid in interpreting previous data on the metamorphosis of function in the head of salamanders.

The physiological cross‐sectional area of nine head muscles was calculated by measuring fibre angles, fibre lengths, and muscle mass in two samples of tiger salamanders obtained just before and just after metamorphosis. The major mouth‐opening muscles (rectus cervicis and depressor mandibulae) exhibit a significant decrease in estimated maximum tetanic tension (MTT) across metamorphosis of about 36%. The jaw‐closing muscles (adductor mandibulae internus and externus) and the head‐lifting muscles (epaxials) also decrease in MTT but not significantly. The muscles associated with tongue projection during feeding on land (the subarcualis rectus I, geniohyoideus, interhyoideus and intermandibularis) all show a slight increase in MTT at metamorphosis.

Metamorphic transformation of feeding behaviour in Ambystoma tigrinum involves changes in performance, the design of skeletal elements, changes in muscle force‐generating capability, and changes in hydrodynamic design from unidirectional flow in larvae to bidirectional flow during aquatic feeding after metamorphosis. Although muscle activity patterns during aquatic feeding do not change across metamorphosis, tongue‐based terrestrial feeding involves a suite of novel muscle activity patterns, morphological characters acquired at metamorphosis, and a metamorphic increase in the masses of muscles important in tongue projection.
Annual variation in the timing of reproduction in Antarctic fur seals, Arctocephalus gazella, at Bird Island, South Georgia
Authors: Duck C. D.
Published: March 2009

The arrival of Antarctic fur seals at a breeding beach on Bird Island, South Georgia, was studied over five consecutive breeding seasons, 1983 to 1987. Experienced bulls arrived first and established breeding territories on the beaches in anticipation of the arrival of the cows. Male arrival, which is less synchronous within years than female arrival, was significantly later in 1987 than in any other year. Female arrival, estimated by pup birth date where necessary, was highly synchronous; it usually started when 80% or more of potential territory sites were occupied by males. Cows arrived significantly later in 1984 and 1987 than in 1983, 1985 or 1986. The late arrival of both males and females in 1987 is attributed to unusually severe climatic conditions during the preceding winter. The late arrival and reduced fecundity of females in 1984 is attributed to markedly reduced food availability during the austral winter and summer of 1983. Males were not affected in 1984 because they could move away from the area of reduced food availability earlier than females and because they have a more varied diet. Factors influencing the winter distribution, the timing and pattern of arrival and the breeding of male and female Antarctic fur seals are discussed.
Diet and feeding ecology of great black‐backed gulls (Laws marinus) at a southern Irish breeding colony
Authors: Buckley Neil J.
Published: March 2009

The diet of great black‐backed gulls (Larus marinus) on Cape Clear Island, Ireland consists largely offish and auks. Other foods, including mammals, crabs and goose barnacles (Lepas), represent less than 10% of the diet by weight. Most fish consumed are obtained as waste from fishing boats. The use of otoliths to determine fish dimensions and problems with the technique are discussed.
Patterns of cranial sexual dimorphism in certain groups of extant hominoids
Authors: O'Higgins P. , Moore W. J. , Johnson D. R. , McAndrew T. J. , Flinn R. M.
Published: March 2009

This paper presents a study of patterns of cranial variation within and between extant hominoids. Particular attention is paid to the relationship between sexual dimorphisms and size differences between sexes. It emerges that shape contrasts between sexes are closely linked to size differences whilst variance dimorphism appears to be relatively independent of size effects. This study demonstrates that there are differences between the hominoids in their magnitudes and patterns of sexual shape contrasts. These types of differences are also found to exist between subgroups of modern humans. It is suggested that the differences which occur between hominoid groups in their patterns of sexual dimorphism are probably the result of a mixture of time and rate hypermorphoses (in males relative to females) acting upon different ontogenetic trajectories. The findings of this study suggest the need for caution in extrapolating from the sexual dimorphisms found in living hominoids to hypothesized dimorphisms in fossils.
A can of worms
Authors: Southgate V. R. , Rollinson D. , Vercruysse J.
Published: March 2009

The Scientific Meeting of the Zoological Society of London held on 13 March 1990 consisted of three reports on different aspects of the biology of schistosomes, with particular emphasis on the interactions of schistosomes with their hosts and schistosomes with other schistosomes.
Neolepetopsidae, a new docoglossate limpet family from hydrothermal vents and its relevance to patellogastropod evolution
Authors: McLean James H.
Published: March 2009

Six new species of limpets from hydrothermal vents at spreading centres, hydrothermal vents on seamounts, or cold sulphide seeps are described in three new genera in the new family Neolepetopsidae. Anatomy is detailed separately by V. Fretter (1990). The family is considered to be a living descendant of the Palaeozoic‐Mesozoic family Lepetopsidae (proposed herein), based on Lepetopsis Whitfield, 1882. Both families are placed in the new superfamily Lepetopsacea, new suborder Lepetopsina, order Patellogastropoda.

New genera and species are: Neolepetopsis, type species N. gordensis, from the Gorda Ridge, and three additional species: N. densata, from an active sulphide chimney near 12°N on the East Pacific Rise, N. verruca from a sulphide chimney near 21° N on the East Pacific Rise, and N. occulla from hydrothermal vents on the caldera floor of Green Seamount near 21° N; Eulepetopsis, type species E. vitrea, from hydrothermal vents at the Galapagos Rift and the East Pacific Rise near 21°, 13°and 11°N; Paralepetopsis, type species P. floridensis, from cool, hypersaline, sulphide seeps at the base of the continental slope off the west coast of Florida.

Inclusion in Patellogastropoda is indicated by plesiomorphic characters: symmetrical shell lacking coiled phase, no epipodium in adult, single dorsally arched jaw, docoglossate dentition with a licker below the tip of the radula, both left and right kidney, and gonad discharging through right kidney.

The radula differs from that of other patellogastropods in having the denticle caps delicate and non‐mineralized, the shafts articulating with shafts and cusps of adjacent teeth in the row and with those in adjacent rows, and in having some capacity for longitudinal bending. The rachidian is well developed; the first two pairs of lateral teeth are regarded as homologues of the inner lateral teeth of Patella; the third lateral tooth is larger than the others and is considered a modified pluricuspid tooth; there are two pairs of plate‐like marginals. Tooth morphology differs in each genus but all have a very long second lateral with a strong mid‐shaft nub to articulate with the overhanging edge of the pluricuspid.

The neolepetopsid radula is interpreted as close to that of the patellogastropod archetype except for its lack of mineralization and reduction in the number of marginal teeth. The radula in living docoglossate outgroups (chitons and monoplacophorans) is mineralized and the teeth are articulating. Articulating teeth are therefore regarded as plesiomorphic in patellogastropods.

I speculate that articulating teeth may have been characteristic of Palaeozoic and early Mesozoic patellogastropods and that the non‐articulating, straight‐shafted and rapidly replaced teeth of extant Patellina may have arisen in the Mesozoic, a time at which patellogastropods of modern appearance underwent a radiation in shallow‐water habitats.
Foraging behaviour of the little penguin, Eudyptula minor: initial results and assessment of instrument effect
Authors: Gales R. , Williams C. , Ritz D.
Published: March 2009

We investigated the foraging behaviour of little penguins using a new archival electronic activity recorder which simultaneously measures speed and depth against time. We present the first integrated data of foraging behaviour of two little penguins, from which we were able to distinguish between several types of travelling and foraging behaviours. The little penguins foraged mainly within 15 m of the surface and travelled at speeds between 8 and 9 km h‐1. Using attachments ranging between 1.4 and 11.8% penguin cross‐sectional area (0.1 and 6% penguin mass), and isotopic water, we also assessed the effects of carrying devices while foraging. Both water influx and metabolic rates were significantly lower in penguins carrying devices, compared to penguins foraging without devices attached. Even the relatively small attachments resulted in a decreased foraging efficiency and we suggest that there is no simple or fixed relationship between size of device and the effect on the bearer.
The function of daylight flying in British bats
Authors: Speakman J. R.
Published: March 2009

A national survey of the incidence of daylight flying of bats in mainland Britain was organized from September 1985 until March 1988. A total of 420 records of daylight flying were received by 1 May 1988. One hundred and forty‐four reports were from winter (October to March), 271 from summer (April to September) and five were undated. Peak activity occurred during April and in August/September.

Activity in both winter and summer was greatest between 12:00 and 16:00h. The numbers of bats involved in each sighting varied between 1 and 200. In summer 87% and in winter 91% of observations were of single individuals. Numbers of daylight‐flying bats, relative to roost visitor reports sent to the Nature Conservancy Council, increased with increasing latitude during both summer and winter. This means that an individual is more likely to fly in daylight the further north in Britain it lives. The effect of day‐to‐day variation in climatic variables on emergence was investigated for records from 1987. In April 1987 emergence occurred on days which followed significantly cooler nights than nights preceding days without emergence. During the remainder of the summer of 1987, however, no climatic effects were significant. During winter 1987 emergence occurred on days which were significantly warmer and sunnier.

These data suggest that during summer the primary function of emergence during daylight is to feed to make good energy deficits that have accrued because of inadequate intake during nocturnal foraging. During winter, bats time their daylight emergences to coincide with good feeding conditions, as has been shown previously for winter nocturnal emergence. It is possible daylight emergence occurs during winter primarily because the endogenous cycle during hibernal torpor cannot accurately synchronize arousal with periods of darkness.
Ovarian egg size and number in relation to female size in five species of parasitoid wasps
Authors: O'Neill K. M. , Skinner S. W.
Published: March 2009

Within five species of parasitoid wasps of the families Pteromalidae (Morodora armata Gahan, Muscidifurax zaraptor K. & L., Nasonia vitripennis (Walker)), Bethylidae (Goniozus legneri Gordh), and Tiphiidae (Myzinum quinquecinctum (Fabricius)), we found significant positive correlations between female body size and both the number and the size of the mature oocytes present in the ovaries. These data are discussed with reference to current clutch size and egg size models and biological information available on these species.
Function of red axial muscles of carp (Cyprinus carpio): recruitment and normalized power output during swimming in different modes
Authors: Van Leeuwen J. L. , Lankheet M. J. M. , Akster H. A. , Osse J. W. M.
Published: March 2009

This paper offers an analysis of the recruitment and normalized power output of the slow oxidative (red) axial muscles of the carp, during swimming in two different modes. Recruitment patterns of the muscle fibres and swimming movements were measured by synchronized electromyography and cinematography. The ultrastructure of the muscle fibres along the trunk was measured by electron microscopy. Strain fluctuations and normalized power along the trunk were estimated using a model, as direct measurement was impossible. The model takes into account structural parameters of the sarcomeres, modulation of sarcomere force as a result of changing sarcomere length, modulation of cross‐bridge force owing to the force‐velocity relationship, and rate of tension rise and of tension decline as a result of fibre properties and stimulation. In continuous swimming, the amplitude of the fluctuations in the strain was constant along the trunk, owing to a remarkable coherence between the amplitude of body curvature and the position along the body of the red muscle fibres with respect to the vertebral column. However, the strain range and speed of contraction at which the fibres were active changed along the trunk in continuous swimming as well as in ‘kick and glide swimming’. During continuous swimming, the fibres along the trunk had a period of negative active power production followed by a period of positive power production. Anteriorly, the positive phase was most important, with a close to optimal power production in a plateau phase, so that net positive work was produced in a swimming cycle. Posteriorly, net negative work was done. In the anal region, the amounts of positive and negative work almost balanced each other. During the first tail strike in intermittent swimming, peak positive normalized work for an activated fibre was produced in the anal region. For this initial tail strike, fast muscle fibres were calculated to work more effectively than slow fibres. Fast fibres were needed to generate kick and glide swimming.
Environmental determinants of intraspecific variation in body weight in baboons (Papio spp.)
Authors: Dunbar R. I. M.
Published: March 2009

Mean body weights of baboons differ considerably between populations for both males and females. This paper examines possible environmental causes of these differences. Mean annual rainfall and mean annual temperature are shown to be the two main factors responsible. Mean body weights for both sexes are a quadratic function of rainfall. Possible reasons why this might be so are examined.
Morphological variation and age‐class determination in overwintering tadpoles of the tailed frog, Ascaphus truei
Authors: Brown Herbert A.
Published: March 2009

The morphological variation and development of different age classes of Ascaphus tadpoles is described for a subalpine population in the North Cascade Mountains. Adult females lay eggs in mid July, and embryos develop into hatchling tadpoles in late August. The torrent‐adapted tadpoles develop in cold waters, overwinter in ice‐covered streams and complete metamorphosis in four years. In September/October there may be five age‐classes of tadpoles: cohort 0, hatchling tadpoles (total length (ToL) = 11 mm); cohort I, one‐year tadpoles (ToL = 32 mm); cohort 2, two‐year tadpoles (ToL = 36 mm); cohort 3, three‐year tadpoles (ToL = 42 mm); and cohort 4, metamorphosing tadpoles or recently transformed frogs (ToL = 20 mm). Determination of these age‐classes is based upon total length, body weight and hind limb and forelimb differentiation. The limb buds appear in the first year of tadpole development, but the forelimbs are hidden by the body wall and branchial chamber, and the hind limbs are concealed by the anal fold.

Arguments are presented from the data of total size‐frequency and morphological differentiation and a review of the literature that the larval life period in montane populations is not two or three years, as is commonly accepted, but is approximately four years.
On the central nervous system of Smeagolidae and Rhodopidae, two families questionably allied with the Gymnomorpha (Gastropoda: Euthyneura)
Authors: Haszprunar Gerhard , Huber Georg
Published: March 2009

The central nervous systems (CNS) of Smeagol manneringi Climo, 1980 (Smeagolidae), of Rhodope veranü Kölliker, 1847, and of Rhodope transtrosa Salvini‐Plawén, 1989 are redescribed in detail. The smeagolid CNS exhibits diagnostic pulmonate characters (procerebrum, cerebral gland, dorsal bodies). Sharing a distinctly structured abdominal ganglion and other peculiarities, the Smeagolidae are closely related to the Onchidüdae, and both families are united as Onchidioidea. The consequences of this close relationship for the origin and evolution of the Gymnomorpha are discussed and the value of the pulmonate CNS for phylogenetics is reconsidered. On the basis of neural characters, which are correlated with the mode of breathing organs, the Pulmonata are divided into Basommatophora, Systellommatophora (Otinidae and Gymnomorpha) and Eupulmonata (ord. nov.: Trimusculidae, Ellobüdae, Stylommatophora).

In contrast, the CNSs of the rhodopid species lack the pulmonate attributes, but show diagnostic opisthobranch characters such as a rhinophoral nerve. Accordingly, the Rhodopidae are excluded from the Pulmonata and are classified as a separate order Rhodopemorpha among the Opisthobranchia.
Regulation of primary spermatogonial proliferation in the frog (Rana esculenta): an experimental analysis
Authors: Rastogi R. K. , Di Matteo L. , Minucci S. , di Meglio M. , Iela L.
Published: March 2009

In order to study the regulation of primary spermatogonial (SPG) proliferation in the frog (Rana esculenta), mitotic and labelling indices of these cells were analysed, in vivo and in vitro, under different experimental conditions and periods of the year. Hypophysectomy, irrespective of the period of the year and independent of temperature, showed a remarkable negative influence on the mitotic or labelling index of the primary SPG. Replacement therapy with homologous pars distalis homogenate stimulated the proliferative activity, the stimulation being of significantly greater magnitude at 18°C than at 4°C. In parallel, mitotic index in vitro, in different periods of the year, after a 24‐h incubation, was significantly higher at 20°C than at 8°C. At 2°C no 3H‐thymidine labelling of the primary SPG was observed. Primary SPG labelling index in vitro increased with temperature, reaching the highest value at 15°C; it was, however, very low at 28°C. Under in vitro conditions FSH and LH stimulated primary SPG proliferation only when given together, but in vivo hypophysectomy stimulated SPG proliferation independently; GnRHa, thyroxine and prolactin were strongly stimulatory. The present in vitro data confirmed that testosterone acts synergistically with FSH‐like substances to influence SPG proliferation. Unilateral castration rapidly increased the labelling index of the primary SPG in the remaining testis and this increased proliferative activity is assumed to be responsible for increased spermatogenetic activity and augmentation of testis mass later in time. It is suggested that temperature represents the constraint which controls the primary SPG responsiveness to hormonal factors.
Sperm competition and reproductive success in the decapod Inachus phalangium (Majidae): a male ghost spider crab that seals off rivals' sperm
Authors: Diesel Rudolf
Published: March 2009

Parker's (1970a) hypothesis that the overlap of multiple mating sperm in the female's storage organs promotes sperm competition is tested here for the first time in Crustacea: specifically, the mechanisms and consequences of sperm competition are detailed for the spider crab Inachus phalangium. Females of this species store ejaculates from successive copulations with different males discretely and consecutively in sac‐like twin seminal receptacles. During copulation males transfer a large quantity of a sperm‐free seminal plasma, followed by the sperm which is stored in small spermatophores and forms a densely‐packed sperm packet. It was shown, using 3H‐thymidine‐labelled ejaculate, that the last male to mate displaces the ejaculate of his predecessors dorsally into the apex of the receptacle. Sperm of previous matings are sealed in with the hardening seminal plasma (sperm gel) and are thus prevented from being used to fertilize eggs, while the last male to mate places his sperm closest to the oviduct and vaginal openings. In experiments using the ‘sterile‐male’ method, sperm from the last male to mate gained all fertilizations in subsequent broods. The seminal plasma forms the sperm gel in ghost spider crabs which is used for displacement of previously stored sperm, whereas various other brachyuran taxa use seminal plasma to produce the sperm plug, which prevents a male's sperm from being displaced.
A new species of land planarian preying on termites in Kenya (Platyhelminthes: Turbellaria: Tricladida: Terricola)
Authors: Jones H. D. , Darlington Johanna P. E. C. , Newson R. M.
Published: March 2009

A new species of land planarian is described from Kenya. Microplana rermirophaga sp. nov. preys on termites by capturing them at the openings to their nest. The pharynx is unusually far forwards for a land planarian and this is probably related to the active nature of the prey. There is an anterior depression caused by the termination of parenchymal longitudinal muscle bundles which might act as a sucker. All specimens are immature which leads to some difficulty in assigning the species to a genus.
Behaviour, population changes and dispersal of mountain hares (Lepus timidus) in Scotland
Authors: Hewson Raymond
Published: March 2009

Mountain hares in north‐east Scotland spent the day in forms in long heather and moved downhill in the evening to feed in hill pastures. Here they grazed intensively, often in groups of 4–6 individuals. In June and July adult females, then pregnant or lactating, grazed in daylight on the pastures. Leverets spent less time grazing, and more in play and exploration. They spent the day in cover near the feeding areas, and if disturbed during grazing crouched or went into cover, while adults fled. During 1982 and 1983 males predominated in groups of grazing hares, but in 1984 both sexes were equally represented. These changes in sex ratio were reflected in the increased proportion of females trapped for marking between February and late July during 1982–86. There was a dominance order related to weight among male hares and dominant hares approached more females. There was no firm evidence of mate‐guarding. Males approached females regardless of their oestrous state and were usually rebuffed with varying degrees of intensity including striking and chasing. There were no interactions between females. Adults of both sexes chased leverets for short distances but leverets joined groups of feeding adults. Neither leverets nor first‐winter hares showed evidence of dispersal. Mountain hares avoided sheep and cattle and there were fewer hares after the arrival of sheep in May.
Mechanical analysis of the sea‐urchin lantern: the overall system in Paracentrotus lividus
Authors: Andrietti F. , Carnevali M. D. Candia , Wilkie I. C. , Lanzavecchia G. , Melone G. , Celentano F. C.
Published: March 2009

The dental apparatus or Aristotle's lantern of sea‐urchins is a complex system of interacting skeletal ossicles, joints, muscles and ligaments arranged in a rigorous geometry and involved in a variety of activities. In this paper we study the movement of the whole lantern system modelled as a rigid body. The model lantern is constrained at its apex by the peristomial membrane and its movement is controlled by five pairs of antagonistic forces (retractor and protractor muscles). The other main forces applied to the lantern are the elastic reactions of both muscles and ligamental structures (compass depressors and peristomial membrane). The lantern is allowed to perform vertical movements and lateral inclinations but cannot rotate around its main axis. The equilibrium conditions of the system have been found by means of a numerical iterative procedure for solving non‐linear equations. The results of the present analysis allow simulation of the overall mechanical activity of the lantern taking into account the experimental data regarding active and passive muscular forces and the tensile constraints due to ligaments.
Feeding ecology and foraging behaviour of the Namib Desert golden mole, Eremitalpa granti namibensis (Chrysochloridae)
Authors: Fielden L. J. , Perrin M. R. , Hickman G. C.
Published: March 2009

Eremitalpa granti namibensis is a small, blind insectivorous mole endemic to the sand dunes of the Namib Desert. Unlike most other subterranean mammals, E. g. namibensis lacks a permanent burrow system and forages for its prey on the dune surface at night. This study examines the natural dietary habits and foraging behaviour of E. g. namibensis in relation to resource abundance and distribution in the Namib dunes.

Stomach content analysis revealed termites as the major dietary item with other invertebrates being of only minor importance. Biomass of potential prey items was found to be low and food resources patchily distributed. It is suggested that desert moles opportunistically exploit a sedentary prey resource which occurs in patches of high concentrations, hence avoiding the energetic costs implicit in pursuing more mobile prey. Qualitative and quantitative descriptions of nocturnal foraging paths were undertaken so that searching behaviour could be related to the variation and distribution of food items. It is concluded that movement patterns of moles are effective in encountering localized areas of high prey concentrations and in minimizing energy expenditure in an energy‐sparse environment.
Patterns in the production of latrines by water voles (Arvicola terrestris) and their use as indices of abundance in population surveys
Authors: Woodroffe G. L. , Lawton J. H. , Davidson W. L.
Published: March 2009

Water vole latrines were studied on four of the principal rivers in the North Yorkshire Moors National Park. Water voles occupied ‘core’ and ‘peripheral’ sites on these rivers. Core sites were marked by latrines and held breeding colonies of voles; animals at core sites were readily captured. Peripheral sites were not marked by latrines, but showed erratic water vole activity as measured by activity indices (tracks m‐1 of muddy bank month‐1). It was never possible to catch voles at these peripheral sites, and there was no evidence of breeding.

Latrines on core sites were not maintained outside the breeding season. The appearance of latrines coincided with the start of the breeding season, and while they were maintained, latrines provided a useful guide to the number of animals in the area. A curvilinear response was obtained between latrine production and date, with production rising steadily from early spring until mid‐to‐late summer, which suggests that latrines signal sexual activity.

Future studies on the distribution of water voles should use a variety of techniques. Latrine surveys will only be applicable during the breeding season at core sites. Similarly, live‐trapping will only detect water voles at core sites. Tracking provides the best evidence that water voles are present at peripheral sites even though they may not be breeding or entering traps.
Behavioural osmotic control in the euryhaline diamondback terrapin Malaclemys terrapin: responses to low salinity and rainfall
Authors: Davenport J. , Macedo E.‐A.
Published: March 2009

Diamond terrapins, Malaclemys terrapin Latreille, inhabit salt marshes and estuaries where they may encounter sustained high salinities for weeks or months. Terrapins can discriminate between salinities. When salt‐loaded they avoid drinking high salinities (27.2–34.0%), drink small amounts of salinities which are a little more concentrated than the blood (13.6–20%), and drink copious quantities of lower salinities (0–10.2%). After seven days in full sea water (34%) they can rehydrate themselves in < 15 min if given access to fresh water. Terrapins are capable of drinking from the thinnest of freshwater films (1.6 mm), exploit menisci and have specific postural responses to collect small quantities of fresh water from horizontal and vertical surfaces. Specimens of Malaclemys terrapin respond to the vibration of simulated rainfall by rapid emergence followed by drinking from thin films, either on the exposed substratum or from the surface of the water column. Under simulated conditions of heavy rainfall they collect rain directly from above.
The reproductive biology of Chrysoblephus laticeps and C. cristiceps (Teleostei: Sparidae)
Authors: Buxton C. D.
Published: March 2009

A detailed histological study showed that in two protogynous sparids, Chrysoblephus laticeps (Cuvier) and C. cristiceps (Cuvier), gametogenesis follows a pattern typical of temperate sparids and marine teleosts in general. Fertilization is external and both species produce numerous small eggs which are pelagic. They have a restricted summer breeding season and gonadal recrudescence is well correlated with temperature and photoperiod. Behavioural observations showed that C. laticeps are pair‐spawners, releasing their gametes well above the substratum after an elaborate courtship routine. The testes of these fishes are small in relation to those of other sparids and are thought to reflect basic differences in the mating systems of sex‐changing and gonochoristic species.
Tests on the locomotion of the elongate and limbless reptile Ophisaurus apodus (Sauna: Anguidae)
Authors: Gans Carl , Gasc J.‐P.
Published: March 2009

A series of Ophisaurus apodus was filmed while traversing plane surfaces, fields of nails and pins at different spacings, and channels of different diameter. Small individuals can practise slow lateral undulation on very rough surfaces, but with increased speed, all shift to slide‐pushing, using either constrained bends of the body or very wide swings of the tail. In fields of closely‐spaced pins, they travel by undulation, often pushing at a limited number of sites and pulling and pushing the trunk among these. Amid pins of wider spacing, the undulation involves some repositioning of curves. In channels, they utilize continuous bend concertina movement with the initial bend formed anteriorly and subsequent ones added, either to the level of the cloaca or on to the tail as well. The cloacal region cannot be established on the basis of locomotor pattern, as the propulsive waves pass smoothly from head to tail. Maximum voluntary velocities (of the centre of gravity) were 13 cm/s for slide‐pushing, 55 cm/s for lateral undulation, and 3 cm/s for concertina movement. Propulsion is entirely effected by bending of the trunk; tests gave no evidence that the dorsal and ventral portions of the integumentary armour show significant anteroposterior displacement relative to each other.
A fossil earthworm embryo (Oligochaeta) from beneath a Late Bronze Age midden at Potterne, Wiltshire, UK
Authors: Piearce T. G. , Oates K. , Carruthers W. J.
Published: March 2009

An embryonic earthworm (Oligochaeta: Lumbricidae), preserved with part of its cocoon wall by calcium phosphate mineralization, has been extracted from a deposit beneath a Late Bronze Age midden in southern England. The structure, possible identity and significance of the specimen are discussed.
Food capture, appetite, digestion rate and efficiency in hatchling and juvenile Crocodylus porosus
Authors: Davenport J. , Grove D. J. , Cannon J. , Ellis T. R. , Stables R.
Published: March 2009

Juvenile estuarine crocodiles captured insects and crabs at or above the water surface by leaps and lunges powered by the hind limbs and tail. The mouth opened as the head cleared the water; most prey were held by sidesnaps of the jaws. Such prey capture was accurate, deliberate and preceded by stalking. In contrast, submerged prey (e.g. prawns) appeared to be detected mainly by touch and detection was followed by undirected, inaccurate ‘snapping frenzies’ which were usually ineffective. Small prey items were swallowed whole under water. Large dense prey (e.g. crabs) were handled and swallowed on land or in very shallow water; large less dense prey (e.g. cockroaches) were swallowed during vigorous water‐treading in deep water, the head being maintained above the water surface.

Young crocodiles ate satiation meals of 9–10% body weight (on a fresh food weight basis) at 30°C, and appetite returned over about 40 h as the stomach emptied. Total gut clearance time for a meal was 4–5 d. Evidence was obtained which demonstrated that young Crocodylus porosus Schneider deliberately eat gastroliths from an early stage. Such gastroliths are retained within the stomach (as were barium/polystyrene spheroids of 1 mm diameter) presumably by the action of the well‐developed pyloric sphincter. X‐radiographs demonstrated that gastroliths are dispersed throughout the stomach contents after a meal and presumably aid digestion.

Assimilation rates for dry mass (77.5%), energy (85.2%) and protein‐N (97.4%) were high in normal juveniles. Animals exhibiting ‘runt syndrome’ showed strong appetite but slow food processing by the gut, together with poor assimilation, especially of protein (35.7%).
Wing movements in the bush‐cricket Tettigonia viridissima and the mantis Ameles spallanziana during natural leaping
Authors: Brackenbury John
Published: March 2009

The movements of the wings during natural jumps made by Tettigonia viridissima and Ameles spallanziana were analysed by means of high‐speed flash photography. Additional data were obtained from the bush‐cricket Oecanthus pellucens. In all cases the wings were usually extended before the hind tarsi had left the ground. In most jumps the first downstroke of the wings was completed before take‐off and the wings probably contributed directly to initial propulsion. All species showed a ‘peel’ variation of the ‘clap and fling’ mechanism in the hind wing downstroke. There was evidence of strong ventral flexure in the forewing at the start of the upstroke in Tettigonia. The implications of the use of the wings in the energetics of jumping are discussed.
A new type of gastropod proboscis: the foregut of Hastula bacillus (Gastropoda: Terebridae)
Authors: Taylor J. D. , Miller J. A.
Published: March 2009

Hastula bacillus (Deshayes) is a small terebrid gastropod which inhabits sandy surf beaches in southern Thailand, where it feeds upon spionid polychaetes. It possesses a foregut anatomy unlike that of any other gastropod. An elongate arborescent muscular organ, known as the accessory proboscis structure, is extended through the mouth during foraging. When retracted, it is folded into an ‘s’ shape in the permanent rhynchodeum. The accessory proboscis structure bears numerous tufts of short, stiff cilia which are associated with pairs or triplets of dome‐like structures. It is suggested that the structures may be chemosensory and concerned with prey location. Hastula bacillus also possesses a retractable labial tube, a long proboscis and buccal tube, dart‐shaped radular teeth, an odontophore, an accessory salivary gland, a pair of salivary glands and a well‐developed venom gland with muscular bulb. A comparison with other terebrid species suggests that H. bacillus is the most plesiomorphic taxon yet described from the family.
Seasonal dynamics of invertebrate drift in a Hong Kong stream
Authors: DUDGEON DAVID
Published: March 2009

Drift samples were taken with paired nets on 19 occasions over a 12‐month period in Tai Po Kau Forest Stream (TPKFS), Hong Kong. Mean drift density (±1 S.E.) was 277·9 ± 25·0 individuals 100 m‐3; peaks in density were apparent during autumn and spring. One hundred and two taxa were recovered from the drift, and the total number of taxa drifting was positively related to water temperatures. Over 99% of the aquatic animals collected in drift samples were insects, 10 taxa of which constituted 67·3% of the entire catch. Baetid mayflies dominated the composition of the drift, comprising 40·4% of individuals caught.

Seasonal changes in the drift of individual taxa were evident, reflecting significant relationships between drift densities and water temperature: Simulium T1 (Diptera). Anisocentropus maculatus (Trichoptera) and Amphinemura chui (Plecoptera) drifted most in winter, whereas Chimarra T1, Polymorphanisus astictus (Trichoptera), Helodes#1 and cf. Rhantus sp. (Coleoptera) were most numerous in summer. Drifting mayflies showed spring (Indobaetis sp., Cinygmina T1, Serratella T2), autumn (Baetiella sp., Pseudocloeon T2), or spring and autumn (Baetis nr pseudofrequentus) peaks which were not clearly related to water temperature. In only two cases (A. maculatus and P. astictus) was TPKFS drift seasonality associated with life‐cycle events. Overall, there was no evidence of community‐level trends in the periodicity of stream drift in this seasonal tropical habitat.
Growth of nestling black kites Milvus migrans: effects of hatching order, weather and season
Authors: HlRALDO F. , VEIGA J. P. , MÁÑEZ M.
Published: March 2009

The growth of black kites Milvus migrans was studied in 1981, 1982 and 1984 at the Doñana Biological Reserve (south‐west Spain). Fifteen variables were submitted to a principal component analysis in order to characterize the growth pattern of the young. In general, in the nestlings that fledged, rapid weight gain corresponded to rapid growth of the tarsus and feathers. For nestlings that starved, tarsus growth took priority over weight gain. Within the same brood, the last‐hatched sibling grew more slowly than its older sibling and the differences between them increased in proportion to the hatching asynchrony. Brood size did not affect growth as clearly as hatching order and hatching asynchrony. Increased rainfall and lower maximum temperature, factors that seem to make the search for food more difficult, had negative effects on the youngest sibling in a multiple brood and on single nestlings. The only environmental variable that had an effect on all of the nestlings was the hatching date.
Annual variation in breeding biology of gentoo penguins, Pygoscelis papua, at Bird Island, South Georgia
Authors: WILLIAMS T. D.
Published: March 2009

The breeding biology of the gentoo penguin, Pygoscelis papua, was studied over a three‐year period (1986–1988) at Bird Island, South Georgia, with particular reference to birds of known age or breeding experience. Laying date varied significantly between all three years, being three weeks later in 1987, when the breeding population decreased markedly. Factors involved in the timing of breeding are discussed. Within years egg‐laying was highly synchronous: 95% of clutches were initiated in 14·5 days or less. The incubation period was 35 days and the laying interval, between the two eggs, 3·3–3·4 days. Chicks creched when 25–30 days old, and this varied between years, possibly related to food supply and chick growth. Chicks left the colony for the first time between 75 and 85 days of age. The breeding population at Bird Island decreased by 20% and increased by 84% in successive years during the study period. Breeding success (chicks fledged per egg laid) varied between 0·33 and 0·65 within colonies, but for the whole island was very consistent over the three years: 0·45, 0·51 and 0·47. Overall, colony differences were not correlated between years. Disturbance from Antarctic fur seals, Arctocephalus gazella, is suggested as the cause of consistently lower breeding success at one colony. Mean egg weight varied annually, and with age of the breeding bird, nest location and, in one year, with laying date. Young, first‐time breeders laid smaller eggs and had lower breeding success compared to older, experienced birds, similar to other seabirds. However, they differed from other species in laying on average earlier than older birds. The relationship between age, egg weight, laying date and breeding success is discussed in relation to predation and seasonal food supply.
The effects of red fox Vulpes vulpes faecal odours on the feeding behaviour of Orkney voles Microtus arvalis
Authors: Calder C. J. , Gorman M. L.
Published: March 2009

Orkney voles Microtus arvalis show avoidance of red fox Vulpes vulpes faecal odours, both in the laboratory and in the wild. Since these voles have been isolated from foxes since Neolithic times it is likely that these responses are innate rather than learned.

When applied to young Scots pine saplings, the fox odour inhibited feeding by voles when alternative foods were available.