bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population differences in behaviour and morphology in the snailLittorina saxatilis:phenotypic plasticity or genetic differentiation?
Authors: Johannesson B. , J.ohannesson K. 
Published: May 2009

The ovoviviparousLittorina saxatilis(Olivi) can be found in many intertidal habitats. Winkles from different habitats have different morphologies and behaviours, which are usually argued to reflect adaptations. Whether the different forms are caused by genetic differentiation or due to phenotypic plasticity is, however, less discussed. Our aim was to document morphological and behavioural differences among one exposed rock poulation, one sheltered boulder population, and one mud flat population, and we reared offspring in a common laboratory environment to see if the differences persisted.We used principal component analysis (PCA), based on 19 measurements, to compare size and shape differences. We also used PCA and linear regression to study allometry and compare growth trajectories. Behavioural differences were studied in three laboratory trials.Littorina saxatillisfrom the rock were relatively small, had small aperture lips, thin shells, blunt spires, and wide columellae. They preferred to stay in cracks and to be above the water surface, and they quickly emerged out of their shells after disturbance.L. saxatillisfrom the boulder shore were relatively large, had large lips, thick shells, pointed spires, and narrow columellae. They preferred open surfaces, submergence, and after disturbance they slowly emerged out of the shell.L. Saxatilisfrom the mud flat were relatively small, had small lips, think shells, pointed spires, and narrow columellae and most behaved similarly to the boulder shore snails. Although less pronounced, most of these morphological and behavioural differences persisted in the snails that we reared in the common environment. This indicates some genetic differentiation. All groups grew allometrically, and most groups differed in growth trajectories, Despite similar ages, the reared females were generally larger than the reared males, indicating higher growth rate in females. Sexual maturation seemed to be reached at a certain size rather than at a certain age. Theories predict genetic diferentiation in intertidal snail species with low dispersal, but some investigations show results that contradict the theories, while others agree with them. Our study confirms the prediction thatL. saxatilisshould be genetically differentiated.
Activity patterns and resource use by sheep and red deer grazing across a grass/heather boundary
Authors: Hester A. J. , Mitchell F. J. G. , Gordon I. J. , Baillie G. J. 
Published: May 2009

Diet selection and activities of sheep and red deer grazing alone and together across a grass (primarily Lolium perenne/Agrostis capillaris) and heather (Calluna vulgaris) boundary, between July and October, are described.Throughout the experiment, both animal species had a much higher proportion of grass than heather in their diet. Time spent grazing on each type of vegetation was similarly greater on grass, and the bite rates of the animals were also more rapid on the grass than on the heather.Red deer spent more time grazing per 24 hours than did sheep, with sheep grazing less during darkness hours than red deer. Total grazing time of both species did not decrease with decreasing daylength from July to October.There were no consistent differences in the diurnal patterns of activity of sheep and red deer, with both species showing 2‐3 large grazing peaks per day.There were no consistent effects of mixing sheep and deer on their grazing behaviour and diet composition.
Geographical variation in the genusDendrelaphis(Serpentes: Colubridae) within the islands of south‐eastern Indonesia
Authors: How R. A. , Schmitt L. H. , Maharadatunkamsi  
Published: May 2009

The south‐eastern islands of Indonesia between Bali in the west and Timor in the east define a region that is at the interface of the Asian and Australasian biogeographic regions. Three subspecies of the colubrid snakeDendrelaphis pictushave previously been recognized from the region:Dendrelaphis pictus pictus(Bali and Lombok);D. p. inornatus(Sumba to Timor); andD. p. intermedius(Sumbawa to Alor). A re‐examination ofDendrelaphis pictusin this region uses multivariate statistics to examine the geographic variation in head‐shield and body measurements within the species. The findings re‐interpret the taxonomy, indicating thatD. pictusfrom Bali and Lombok are specifically different fromD. inornatuson the remaining islands on the Banda Arc. The populations ofD. inornatuson the islands of Sumbawa, Sumba, Sawu, Flores, and Lembata are subspecifically different from those on Roti, Semau, Timor, Alor, and Wetar.Several head‐shield measures are strongly correlated with longitude withinD. inornatus, suggesting environmentally triggered selection gradients. However, for many variables, the two subspecies differ significantly in the direction of the trends which suggests the subspecies respond differently to these environmental gradients. There is evidence thatDendrelaphisindividuals may be transported through the islands by anthropogenic agencies.
The influence of size differntial on agonistic behaviour in the freshwater crayfish, Cherax cuspidatus (Decapoda: Parastacidae)
Authors: Pavey C. R. , Fielder D. R. 
Published: May 2009

The agonistic behaviour of juvenile pairs of intermoult freshwater crayfish Cherax cuspidatus, interacting over space in experimental containers, was examined. The study investigated the effects of differences in Resource Holding Potential (RHP) on social rank, patterns of interaction initiation, and the importance of fighting during encounters between pairs of crayfish. Crayfish were paired with unfamiliar opponents at size classes of 1 : 1, 1 : 0.9, 1 : 0.8, I : 0.7 and 1 : 0.6 using standard carapace length as the RHP index.Larger animals were dominant during significantly more than 50% of replicates at all size classes. Larger animals were dominant at all size ratios lower than 1 : 0.89. Seven smaller animals were dominant at size ratios between 1 : 0.89 and 1 : 0.99. The dominance of smaller animals could not be explained on the basis of morphological measures or age. The influence of prior experience as dominants or subordinates on the behaviour of contestants during these encounters appeared the most likely explanation.Carapace length, body length, and weight were equally reliable RHP indices. Age, number of injuries, and sex were not reliable RHP indices.The probability of initiating the first agonistic bout was independent of relative size for three of the five size classes. Larger initiators of the first bout invariably were successful, while smaller initiators rarely won. The winner of the first bout was the overall dominant during significantly more than 50% of replicates at each size class. The dominant individuals initiated the majority of bouts at all size classes, including the seven replicates where the smaller crayfish was dominant.Fighting (fight time, fight frequency, average bout length), a high intensity behaviour, was an important component of contests at the 1 : 1, 1 : 0.9, and 1 : 0.8 size classes. The significance of fighting was greatly reduced at the 1 :0.7 and 1 : 0.6 classes, indicating that fighting was correlated with the relative size of opponents.
The endocrine basis of the reproductive cycle in the king penguin (Aptenodytes patagonicus)
Authors: Jouventin P. , Mauget R. 
Published: May 2009

What is the breeding frequency of the king penguin? More than 30 years of study and five major investigations, did not answer this question owing to the length (14 months) and the spreading (four months of laying) of reproductive events.Following intensively during three consecutive years nearly 1000 tagged birds in a small colony, we obtained the individual history of a large part of the population. To these demographic and phenological studies, we have associated an endocrinological study validating blood samples and experiments in another colony.The success or failure of a breeding cycle determines the timing of the subsequent breeding attempt. At Crozet Islands, the king penguin can rear one chick every two years at best: a successful breeding is followed by unsuccessful late breeding (or by non‐breeding). So a large part of the population displays an annual periodicity of breeding attempts but with low individual breeding success.The restarting of the reproductive cycle appears basically to be annual, the pituitary responding to the photoperiod. Steroid patterns present classical variations of level according to the reproductive stage. Prolactin (PRL) and luteinizing hormone (LH) are antagonists but, in this species, PRL remains high without external stimulation. To relay after failure in the field. we have experimentally to break down endogenous PRL. So, we have demonstrated that PRL has a key role in the reproductive cycle.Paradoxically, the king penguin is an irregular breeder, quasi‐biennial, although physiologically an annual breeder. In winter, there is not enough food at sea to rear the chick and during four months, the chick fasts. So a successful breeding cycle, which can be shortened to only nine months in captivity, is extended to more than a year for ecological reasons.
Thermoregulation in two population of the Matabeleland mole‐rat (Cryptomys hottentotus nimrodi) and remarks on the general thermoregulatory trends within the genus Cryptomys (Rodentia: Bathyergidae)
Authors: Bennett N. C. , Cotterill F. P. D. , Spinks A. C. 
Published: May 2009

The social Matabeleland mole‐rat Cryptomys hottentotus nimrodi occurs in both the high‐and lowveld of Zimbabwe. The population in the highveld has a mean (± S. D.) resting metabolic rate (RMR) when acclimated for three months in the laboratory of 0.83 ± 0.04cm3 O2 g‐l h‐l (n=12) within the thermoneutral zone (TNZ) of 31‐32°.The body temperature (Tb) within the thermoneutral zone is low 34.4 ± 0.18 (n= 12) and remains stable at ambient temperatures (Ta s) from 25‐32°. Above 32°, Tb increases albeit slightly to 36.6 ± 1.46° (n= 12). The conductance is high 0.17 0.02cm3 O2 g‐1 h‐°‐1 (n= 24) at the lower limit of thermoneutrality. The mean RMR at 18° (the lowest Ta tested) was 2.29 ± 0.11 cm3 O2 g‐1 h‐1, which is 2.75 times that of the RMR in the TNZ.The population in the lowveld has a mean (± S.D.) resting metabolic rate (RMR) when acclimated for three months in the laboratory of 0.95 ± 0.07 cm3 O2 g‐1 h‐1 (n= 12) within the themoneutral zone (TNZ) of 28‐30 °.The body temperature within the thermoneutral zone is low 34.0 ± 0.23 (n= 12) and remains stable at Tas from 25‐30 °. Above 32 °, Tb increases, albeit slightly, to 37.8 ± 1.14 ° (n= 12).The conductance is high 0.14 ± 0.09cm3 O2 g‐1 h‐1°‐1 (n= 24) at the lower limit of thermoneutrality. The mean RMR at 18 ° (the lowest Ta tested) was 1.96 ± 0.12cm3 O2 g‐1 h‐1, which is 2.0 times that of the RMR in the TNZ.These thermoregulatory parameters are compared with published data on other species of Cryptomys from Southern and Central Africa.
Enduring social relationships in a population of crab‐eating zorros, Cerdocyon thous, in Amazonian Brazil (Carnivora, Canidae)
Authors: Macdonald D. W. , Courtenay O. 
Published: May 2009

Crab‐eating zorros, Cerdocyon thous, in Amazonian Brazil weighed 5.2 kg (S.D. 0.6, n= 19), exhibited no sexual dimorphism, lived in social units of 2‐5 adults of > 1 year old, and occupied territories (restricted polygons) of 532 ha (range 48‐1042 ha, n= 21).
The zorros were omnivorous, fruit being the most frequent food (occurring in 57% of 72 faeces in the dry season) comprising 26.4% by volume of undigested faecal remains. Insects were frequently eaten (86%), and vertebrates rarely (15.2%).
Zorros were territorial. The ranges of neighbours overlapped minimally and were very stable in configuration, both from month to month and between dry and wet seasons. Members of each social unit shared on average 88.3% of 200 × 200m grid cells within their territory. Members of male‐female breeding pairs were within 100 m of each other for 63% of the activity period, their proximity being greatest during the mating season (July‐August). Parents travelled in close company with their adult‐sized offspring, and stayed within 100 m for up to 93.3% of the activity period.
Territories differed in habitat composition. Overall, zorros spent most time in wooded savanna (33.9%) and scrub (30.5%). They did not utilize habitats in direct proportion to their availability, using some more (e.g. scrub) and some less (e.g. open savanna) than expected. Habitat preferences differed between wet and dry seasons, with elevated habitats being favoured during the wet season.
Individuals differed in their habitat utilization, and parents had different habitat usage to their yearling offspring; this difference was exaggerated in the dry season when the yearlings used lowlying habitats apparently disfavoured by the parents. Differences in habitat utilization between group members were least in the wet season, when widespread flooding forced the shared use of higher ground.
Each of two social units larger than two individuals comprised a pair and their three adult‐sized offspring (totalling five males and one female). In three cases, a yearling daughter was present in the breeding season, but none of these bred. Non‐breeding offspring were seen frequently in the whelping area and in close company with the breeding pair's cubs. This is the first proof of group‐living in South American zorros.
Five dispersal events were monitored, and revealed a ‘good neighbour’strategy in which newly formed pairs set up their territories adjoining their natal territories. In each case individuals returned intermittently to their original territory where they were in close and amicable company with their parents. One male, having dispersed, returned home frequently without his mate to tend the next generation of his parents’cubs. Of four dispersing males, two subsequently returned to their natal group following the deaths of their mates at least 3‐13 months after their initial dispersal, in one case after breeding elsewhere.
Behavioural and ecological aspects of nuptial flights of the termitophilous phorids Termitophilomyia zimbraunsi and Mesopathusa modesta (Diptera: Phoridae) in Zimbabwe
Authors: Cumming Meg S. 
Published: May 2009

Nuptial flights of Termitophilomyia zimbraunsi were observed over three years (1990‐1993) near the open chimney of an Odontotermes transvaalensis mound in Harare, Zimbabwe. Copulating phoretic pairs landed on the chimney; males quickly disengaged and flew away whilst females ran inside the vent and tore off their wing membranes. Agitated termite workers and soldiers swarmed the rim in a partially successful physical attempt to expel the phorids; the termites appeared to anticipate the threat of invasion. After acquiring the scent of the nest, female phorids ran underground to lay their large single eggs, probably in the hosts’fungus gardens. Nuptial flights occurred throughout the year but only in the early mornings, peaking in the hot dry season and being least in the hot wet season. The flights were highly temperature dependent (15.0‐17.9 °), usually occurring at relatively low light intensities but across a wide range of humidities. Phoresy and sexual dimorphism in wings, mouthparts, food and division of labour in T. zimbraunsi are discussed, as is its termitophilous habit and the responses of termites to it.Although the females of Mesopathusa modesta are apterous, nuptial flight behaviour is very similar to that of T. zimbraunsi. Neither phorid is host‐specific, both species having been found on both Odontotermes latericius and O. transvaalensis mounds, although M. modesta is more common on O. latericius mounds.
Energy allocation in reproducing and non‐reproducing guinea pig (Cavia porcellus) females and young under ad libitum conditions
Authors: Raffel M. , Trillmich F. , Houner A. 
Published: May 2009

Increase in body mass is an overall measure of growth which hides the dynamics of changes in body components. A study of the allocation of resources to growth versus reproduction is particularly interesting in guinea pigs (Cavia porcellus) where females mature early in the growth phase and produce highly precocial young while still growing rapidly.In order to get information on energy allocation in guinea pigs, fat‐free mass (FFM) of young (1‐30 days) and adult females (reproducing vs. non‐reproducing) was determined by measuring TOtal Body Electrical Conductivity (TOBEC; indexed by TOBEC#) which was calibrated by Soxhlet extraction.FFM was predictable from body length alone, but was best predicted as a function of (TOBEC#*length)0.5. Prediction was further improved by separating the data into two sets, for animals of 23 cm and of > 23 cm body length. Fat and total body water (TBW) can also be determined from TOBEC#, but the reliability of fat determinations is low unless samples of 5‐10 equally treated animals can be averaged. The formula developed by Pace & Rathbun (1945) for the estimation of TBW has frequently been used for all kinds of mammals, but is shown consistently to underestimate TBW even in guinea pigs.Using our calibrations, we studied the development of FFM and body fat in young guinea pigs from birth to 30 days, and the development of FFM and fat stores in reproducing, primiparous, and non‐reproducing females of equal age.Young were born with about 11% fat. Young in large litters (3‐5) had relatively and absolutely less fat reserves than young in small litters. In eight young measured on days 1, 3, and 5, fat declined until day 3 and returned to the mass at birth on day 5. Fat mass increased slowly during the lactation period, until day 20, and faster thereafter in weaned young. Relative to body mass, fat decreased from 11.2% at birth to 9.3% on day 30, with a minimum of 6.6% on day 20. Mass of fat on day 30 was independent of litter size. FFM began to grow linearly from day 5 onwards. Body water in FFM varied with age in an inverted U‐shaped pattern.Reproducing females grew in FFM at equal rates to non‐reproducing females, but deposited less than half as much fat until day 210, by which time they had had two litters. Under ad libitum food conditions and a mild thermal regime, reproducing females allocated as much of the available resources to growth in FFM as non‐reproducing females, but reduced storage of fat, instead producing biomass of precocial young.
Associations of testate rhizopods (Protozoa) in the plankton of a Malaysian estuary and two nearby ponds
Authors: Green J. 
Published: May 2009

Plankton samples were collected from the Chukai‐Kemaman estuary in Malaysia in order to determine the distribution of testate rhizopods in relation to salinity. Two nearby freshwater ponds were sampled for comparison.In the ponds, 35 species of testate rhizopods were found, 13 of which were not found in the estuary. From the estuary 53 species were found, of which 31 were not found in the ponds. Some species appeared to have been lifted into the plankton by the rising tide. At a generic level, the Arcella species were very similar in both ponds and estuary (Sorensen Index 80), the Difflugia species were moderately similar (Sorensen Index 47), while Nebela and Quadrullela were present in the estuarine samples, but absent from the pond samples.The salinity gradient ranged from sea water down to a conductivity of 27 μS. All the estuarine stations were tidal. The first freshwater testate rhizopods were found in a region where the conductivity was between 3000 and 4000 μS at high tide. Where the conductivity was below 1000 μS at high tide the number of species rapidly increased, and reached a maximum of 25 in the samples from the lowest conductivities. The flowering tree, Hibiscus tiliaceus, appears to be an indicator of the region where the first freshwater testate rhizopods might be encountered upstream from the sea.
Behavioural manifestation of conception 12 hours after mating in an asocial African rodent, Saccostomus campestris
Authors: Westlin Lilian M. 
Published: May 2009

The pouched mouse, Saccostomus campestris (Cricetidae), is an African rodent, known to lead a solitary life, where the female is overtly aggressive towards all conspecifics, except during the very short time of sexual receptivity, when she will tolerate the presence of a male and mate with him. In the present study, males were introduced to sexually receptive females to study their behaviour after mating and correlate that to the endocrine status of the female at that time.The present paper demonstrates that c. 12 hours after mating (and ovulation), the behaviour of female pouched mice reflects whether conception has occurred or not; conceived females became aggressive towards the male at that time, while non‐conceived females continued to be amicable towards the male during the subsequent phases of that and the following cycle(s), until conception occurred.Aggressive behaviour was not associated with measurable plasma levels of testosterone, and owing to large intra‐ and inter‐individual differences, no relationship was confirmed between plasma levels of oestradiol‐17β and levels of aggression during the oestrous cycle.Approximately 12 hours after mating, plasma concentration of progesterone was significantly higher in females that had conceived than in those that had not. This could not be correlated with the occurrence of aggression in these females, however, as there were no differences in progesterone levels between single, cycling females and mated non‐pregnant females at any stage during the cycle.The presence of a male, vaginal stimulation, and prolactin are not presumed to be involved in suppression of aggression in female pouched mice.
THE ZOOLOGICAL SOCIETY OF LONDON STAMFORD RAFFLES LECTURE 1996 From Gaia to Noah: human responsibilities in nature
Authors: Tickell Sir Crispin 
Published: May 2009

Sir Crispin Tickell is Warden of Green College, Oxford; Chancellor of the University of Kent at Canterbury; Chairman of the Climate Institute of Washington, DC; Director of the Green College Centre for Environmental Policy and Understanding; Chairman of the Government's Advisory Committee on the Darwin Initiative; and Convenor of the Government Panel on Sustainable Development.Sir Crispin was a member of the Diplomatic Service. He was Chef de Cabinet to the President of the European Commission (1977–80), Ambassador to Mexico (1981–83), Permanent Secretary of the Overseas Development Administration (1984–87), and British Permanent Representative to the United Nations (1987–90). He was also President of the Royal Geographical Society (1990–93), and Chairman of the International Institute for Environment and Development (1990–94).He is the author of Climatic Change and World Affairs (1977 and 1986), and Mary Anning of Lyme Regis (1996). He has contributed to many other books on environmental issues (including human population increase and biodiversity). His interests go very wide, and include business and charities. More personally he cherishes mountains, pre‐Colombian art, and palaeo‐history.