bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of supplementary feeding upon the demography of a population of woodmice Apodemus sylvaticus, living on a system of maritime sand‐dunes
Authors: Akbar Zubaid , Gorman M. L. 
Published: March 2009

The woodmouse is a characteristic rodent of deciduous woodland but it also lives on maritime sand‐dunes. The population density of woodmice on sand‐dunes is much lower than in woodland. Hue we test the hypothesis that this difference is due to the fact that woodland provides substantially more food than do sand‐dunes. Our experimental approach was to provide supplementary food (wheat grain) to a sand‐dune population for a period of 22 months and to compare demographic responses with a control population.The supplemented population increased rapidly and reached a size 6–7 times that ofthe control population. The overall annual pattern of changes in density were similar in both populations with minimum numbers in late spring, maximum numbers in autumn and a loss of individuals over the winter. The woodmice receiving supplementary food bred earlier and for longer than did the control mice.
Reproductive parameters of the grey goshawk (Accipiter novaehollandiae) and brown goshawk (Accipiter fasciatus) at Abergowrie, northern Queensland, Australia
Authors: Burton A. M. , Alford R. A. , Young J. 
Published: March 2009

Thirty‐one A. novachollandiae breeding attempts on 14 territories were located near Abergowrie, Queensland (18° 27' S, 146° 0' E) between 1986 and 1989. Twenty‐nine breeding attempts by A. fasciatus were located on 14 territories in the same study area.Both species began nest construction around the first week of September. Egg‐laying was complete by mid‐October. Mean clutch size of A. nouurhollandiue was 2.0 and of A. fusciutus was 3.0. Both species incubated for about 30 days. The nestling period of A. nouuehollundiue was 30–38 days; that of A. fusciutus was 32–37 days. Post‐fledging period for both species was 38–43 days. Neither species bred outside the ‘spring’ (August‐December) period.Both species tended to nest near the edge of large (> 50 ha) forest or woodland tracts bordering young pine P. curibueu plantations. They did not nest near sugar cane.Accipiter nozmehol/undiuc tended to nest in larger trees, which occurred in denser habitats: closed forest and tall open woodland. Nests were placed on forks at the end of major horizontal or slightly oblique branches. Accipiter, fusciutus tended to construct nests in smaller trees; nests were correspondingly closer to the trunk. Differences in the overall size of nest trees were attributed to habitat differences.Interspecific distances to nearest‐neighbour were less than intraspecific distances. Close interspecific nesting was related to habitat heterogeneity and prey availability within the study area.Ninety‐four percent of A. nouuehoNundiue nests of known outcome were successful, while the success rate of A. fusciafus was 62%. The total offspring production per pair of the species was similar, but the greater rate of nest failure for A. fusciatus meant that this species fledged fewer young per initial nest than A. nouuehollundiur. Tropical thunderstorms were responsible for most nest failure and nestling deaths. Both species used nests repeatedly only after successful nesting.
The modulation of rhythmic behaviour in the pulmonate slug Limax pseudoflavus by season and photoperiod
Authors: Ford Douglas J. G. , Cook Anthony 
Published: March 2009

Freshly caught samples of slugs were maintained at constant temperature and humidity but at day lengths (from 5 h 50 min to 16 h darkness) appropriate to the time of year at which they were collected. The duration of their feeding and crawling activities as well the total time spent active was recorded by time‐lapse cinematography.Total activity was significantly higher in autumn and spring than in summer and winter. The activity period was symmetrically disposed about the midpoint of the dark period except for two samples in autumn. At scotoperiods longer than about 12 h, activity onset was delayed relative to the start of the dark period and activity cessation was advanced relative to the end of the period, resulting in the short duration of activity seen in winter. At scotoperiods of less than 12 h the duration of activity was relatively independent of scotoperiod.In spring the total time spent crawling was composed of relatively few bouts of long duration whereas in the autumn the number of bouts was greater and their duration shorter. The winter was characterized by slugs making single journeys to and from the food. While emerged these slugs stayed in close association with the food but not necessarily feeding on it.These data are discussed in terms of comparisons with homoiothermic nocturnal animals. It is concluded that seasonal responses in poikilothermic animals are likely to be limited by the hazards of winter even when such animals are maintained in apparently non‐limiting conditions.
Morphological variation in shallow‐water octopuses (Mollusca: Cephalopoda)
Authors: Voight Janet R. 
Published: March 2009

Whether the study of external morphology can increase our knowledge of shallow‐water octopuses and their biology is tested by multivariate morphometric analyses. The extent of morphological variation among 20 species from the Atlantic and eastern tropical Pacific Oceans is explored, and four hypotheses are addressed: (1) that octopuses show secondary sexual dimorphism; (2) that remote, ostensibly conspecific populations are morphologically distinct; (3) that morphometric characters contribute to resource partitioning among sympatric species; and (4) that morphology is predictably associated with habitat.Results of principal components analysis show most species to be very similar in shape. Arm length contributes most shape variation; other characters contribute little. Principal components and size‐free discriminant analyses refute each of the hypotheses considered. The morphological similarity of isolated Atlantic populations may be a symplesiomorphy, but information on the planktonic phase of the octopus lire cycle supports the possibility of dispersal across the Atlantic Ocean. Size, not directly treated here, may significantly affect some aspects of octopus biology. Increased female size may evolve due to selection for increased fecundity and intraspecific niche partitioning. Size may also indicate interaction within and among species. Characters of shape, deemed essential to species descriptions, do not appear to be able to identify most specimens, nor to increase our understanding of octopus biology.
Investigating the evolutionary effects of one feature on another: does muscle spread suppress caudal autotomy in lizards?
Authors: Arnold E. N. 
Published: March 2009

Hypotheses of secondary evolutionary change, where alteration in a particular feature is thought to result in change in another, can be tested in two main ways. First, phylogenies can be used to identify separate cases where one of the features changes and each case can then be examined to see whether the other change also actually takes place and if the perceived sequence of the alterations is appropriate. Secondly, the mechanism by which change in the second feature is supposed to be effected can be scrutinized and, in some cases, subjected to experimental investigation.This approach was applied to a recent hypothesis, that backward spread of the caudifemoralis longus muscle in the tail base of lizards was the primary cause of loss of capacity to autotomize the tail. Some 23 to 25 independent cases of total autotomy loss in adult lizards were identified. In all but six of these there was no substantial spread of the muscle. In two of the remainder, the muscle appears to have spread ufiev autotomy loss, and another case cannot be tested properly as information about relationships is equivocal. The final three cases exhibit extension of the caudifemoralis longus before autotomy loss, but the latter is not found in related species that also inherit muscle extension, which suggests that other causal factors may be involved. In about 15 other cases, where autotomy becomes restricted to the tail base, there is no marked spread of the caudifemoralis longus. The proposed functional link between muscle extension and autotomy loss is also discussed and discounted
Interannual variation in the breeding biology of the Antarctic prion Pachyptila desolata at Bird Island, South Georgia
Authors: Liddle G. M. 
Published: March 2009

Interannual variation in aspects of the breeding biology of Antarctic prions was studied for three summers (1989–1992) at Bird island, South Georgia. Egg size, mass and incubation period remained constant. Laying, hatching and fledging were significantly delayed and less synchronous in 1991/92 (range of laying dates 51 days compared to 10–15 days in the two other seasons). This was due to an unusually cold and protracted winter, with ice blocking burrows into the spring, restricting availability of nest sites. Brooding lasted longer in 1991/92 but the overall fledging period was unchanged. Skeletal growth rates did not vary amongst years; growth in mass was slower in 1989/90 but fledging mass was similar in all three years. In 1989/90 and 1991/ 92 later hatched chicks grew (in mass) faster. The survival of chicks from hatching to fledging did not vary amongst years or with hatching date. Feeding frequency was similar between years, once allowance had been made for starlit nights. Thus late and asynchronous breeding in 1991/92 did not result in reduced breeding success either through predation or starvation.Crustaceans formed 98–99% of the mass of the identifiable portion of regurgitated food samples. Significant annual variation was found within these crustaceans with the presence of krill (least in 1990/91) being inversely related to that of amphipods and copepods. There was no relationship between diet composition and chick growth or survival. Other seabird species, lacking the morphological specialization for feeding on copepods and amphipods, had very low breeding success in 1990/91, when krill was scarce.
Intraspecific variation in the dolphinsLagenorhynchus albirostrisandL. acutus(Mammalia: Cetacea) in metrical and non‐metrical skull characters, with remarks on occurrence
Authors: Mikkelsen Anna Maria Hill , Lund Anders 
Published: March 2009

Intraspecific multivariate data analyses of 27 metrical and 20 non‐metrical characters were performed on skulls ofL. albirostris(Gray, 1846) andL. acutus(Gray, 1826) to distinguish between possible populations from the eastern and the western North Atlantic.The results from principal component (PC) analysis and partial least square (PLS) analysis suggest that the skulls ofL. albirostriswere taken from separate populations, whereas those ofL. acutuswere not.A difference in the occurrence‐patterns of the two species was found, indicating that the degree of intraspecific variation may be linked to the water‐depth related distribution.
The breeding ecology of Cancer gracilis (Crustacea: Decapoda: Cancridae) and the mating systems of cancrid crabs
Authors: Orensanz J. M. , Parma A. M. , Armstrong D. A. , Armstrong J. , Wardrup P. 
Published: March 2009

Brachyuran crabs in the family Cancridae are found in a variety of habitats, ranging from ‘open’ sandy or muddy grounds to ‘structured’ rocky bottoms rich in refuge space. Cancer gracilis Dana inhabits shallow open habitats in the north‐east Pacific Ocean. Females in all reproductive conditions aggregate in relatively small areas, where mating activity appears most intense. Maximum mating activity was observed towards the end of the spawning/hatching season (August). Females play an active role in mating, often initiating interactions with the prospective male partner. Mating in the field was non‐assortative with respect to size. There was no indication of direct mate choice by either males or females; resolution of male‐male competitive interactions was size‐based. Males below minimum mating size (77 mm carapace width) had spermatophores in the vas deferens but did not react to receptive females.Sperm competition is likely because sperm can be retained across moults and multiple copulations are possible within a receptive period. Female spermathecae are of the ‘ventral’ type (contrary to what has been indicated for cancrids), and during intercourse are beyond the reach of male gonopods. Mechanisms to exclude competing sperm include male‐produced sperm plugs and post‐copulatory mate guarding.Results are discussed in the context of the ‘structured‐to‐open’ habitat gradient, which may underlay much of the diversity in cancrid reproductive ecology. We argue that, by comparison with C. magister (a larger size sympatric species also found in open habitats), (1) reproductive asynchrony and female gregariousness in C. gracilis increase the environmental potential for polygyny, resulting in a female defence polygynous mating system, and (2) reproductive asynchrony inflates the operational sex ratio, leading to stronger sexual selection.
Systematics, speciation and biogeography of the dwarf chameleons (Brookesia; Reptilia, Squamata, Chamaeleontidae) of northern Madagascar
Authors: Raxworthy C. J. , Nussbaum R. A. 
Published: March 2009

Brookesia dwarf chameleons, endemic to Madagascar, were surveyed at the following localities in northern Madagascar (north of 16°S): Montagne d'Ambre, Ankarana, Manongarivo, Tsaratanana, Marojejy and Masoala. A total of 15 species occur in this region. Six new species are described and five new synonyms are identified. The genus Brookesia, the most speciose chamaeleontid genus in Madagascar, contains 23 species.Almost all the northern Brookesia species are restricted to rainforest and occupy a relatively narrow elevational range. Although the northern rainforests represent just one‐third of the total rainforest and about 5% of the total island area, 65% of the Brookesia species occur in this region, and 52% are endemic to the northern rainforest. Five new biogeographic regions of the northern rainforest are identified based on centres of Brookesia endemicity: Montagne d'Ambre, Northwest, Tsaratanana, Northeast and East. Speciation is thought to have been facilitated in the north through geographic isolation, with the Tsaratanana mountain range and the dry forests south of Montagne d'Ambre forming barriers to dispersal, and the Tsaratanana mountains acting as a centre of isolation. The fragmented distribution of several Brookesia species of low altitude rainforest suggests a period in Madagascar's history when the climate was wetter and low altitude rainforest much more widespread.
Pre‐ and post‐maturation survival in adults of the damselfly Pyrrhosoma nymphula (Zygoptera: Coenagrionidae)
Authors: Bennett S. , Mill P. J. 
Published: March 2009

The technique of mark‐release‐recapture was used to study survival before and after sexual maturity in adults of the damselfly Pyrrhosoma nymphula (Sulzer). Fewer females were recaptured upon return to water to breed despite no differences in dispersal or daily survival rate between the sexes over the immature period. Because females took longer to mature than males, their poorer recapture rate was attributed to greater overall mortality during their longer maturation phase. Survivorship curves for tenerals marked at emergence suggested that overall survival of immature adults was similar to, if not better than, that of mature adults. The reasons for this are discussed.Jolly's model was used to estimate daily survival rates for mature adults. The assumptions of the model were tested rigorously. Estimates for females were statistically less reliable than those for males. Mean reproductive spans for males and females were 6.8 and 6.6 days, respectively, giving mean total adult lifespans of 19.4 days and 21.6 days for individuals surviving the maturation period.Because neither sex visited the breeding site every day, sampling exclusively at water resulted in underestimation of mean reproductive spans for both sexes. Female reproductive spans were underestimated to a greater extent; because females remain away from water longer between visits, there is a greater chance that they will die before being recaptured.Mean reproductive spans were also underestimated when only a sub‐section of the habitat was sampled. Females were significantly more mobile than males and this increased the likelihood that they would move out of the study area, resulting in more severe underestimation. The importance of obtaining accurate estimates of mature lifespan for females is discussed.
The effects of sex, season and habitat availability on patterns of habitat use by fallow deer (Dama dama)
Authors: Thirgood S. J. 
Published: March 2009

Diurnal habitat use by fallow deer Dama dama was studied between 1986–9 by direct observations from transects of eight populations in sites of differing environmental structure and composition. Sites chosen differed in the overall proportion of woodland cover, and ranged from virtually continuous woodland areas in the New Forest, southern England, to open agricultural sites with only scattered woodland copses.Within both New Forest and agricultural areas, individuals in male groups and female groups showed similar patterns of habitat use. In the New Forest, the habitat used most overall by both sexes was open woodland, with extensive use also made of grassland, woodland clearings and closed woodland. In agricultural areas, most extensive use was made of closed woodland, with open woodland, arable land and grassland used to a lesser extent. Individuals in mixed‐sex groups in the New Forest but not in agricultural areas made more extensive use of grasslands than those in single‐sex groups.Individuals in female groups in the New Forest showed pronounced seasonal variation in habitat use with utilization of open woodland higher in autumn and winter and grassland higher in spring and summer. Individuals in female groups in agricultural areas showed little seasonal variation in habitat use. There were insufficient data to investigate seasonal variation in habitat use by individuals in male and mixed‐sex groups.Availability of habitat types varied widely between study sites. Use of either open or closed woodland remained high in each site reflecting increased selection for woodland resources when they were of limited availability. Fallow deer appeared able to satisfy their ecological and behavioural requirements from a variety of environments through: (i) changing strength of selection of particular habitats to compensate for differing availability; and (ii) substitution of one habitat in one area for a different habitat in another area which offered the same effective resources. This flexibility in resource use parallels observed plasticity in other aspects of fallow behavioural ecology.
The biology, life cycle and ecophysiology of the Antarctic miteAlaskozetes antarcticus
Authors: Block W. , Convey P. 
Published: March 2009

This paper is dedicated to the late Nigel Bonner, who as Head of the Life Sciences Division at British Antarctic Survey, encouraged and supported this research with his characteristic enthusiasm.The cryptostigmatid miteAlaskozetes antarcticus(Michael) is a dominant member of many terrestrial communities in the maritime Antarctic, where it survives extreme temperatures, short cold summers, numerous freeze‐thaw cycles, desiccating conditions and a limited season for growth and reproduction. However, examination of features of its biology, from morphology, through life‐history strategy to physiology, indicate very little specialization to the Antarctic environment.Alaskozetes antarcticusis a herbivore/detritivore, typical of the Cryptostigmata in general, with low feeding and growth rates, long life span and low reproductive output. Physiological specializations exist in the form of low enzyme activation energies and elevated metabolic rates at low temperatures when compared with temperate species, and associated low optimum temperatures for activity, feeding and growth. Growth rates comparable with temperate species are achieved in the field, with an extended life cycle of five years or more as a result of the short growing season, and the ability of all life stages to overwinter equally successfully. Overwintering survival, involving supercooling enhanced by the use of antifreezes such as glycerol, although initially described in Antarctic species, is now known to be characteristic of many temperate relatives, so it is not a specific adaptation to the polar environment. The obvious success ofA. antarcticusin maritime Antarctic terrestrial environments must be attributed to a combination of several features characteristic of the Cryptostigmata in general, rather than to specific polar adaptations.
Life histories, secondary production and microdistribution of Psephenidae (Coleoptera: Insecta) in a tropical forest stream
Authors: Dudgeon David 
Published: March 2009

The ecology of four species of Psephenidae (water penny beetles) was investigated in Tai Po Kau Forest Stream (TPKFS), New Territories, Hong Kong, over a two‐year period. Quantitative benthic samples were taken from different microhabitats in the stream on 47 occasions and, in combination with light‐trap catches of adult beetles, were used as a basis for investigating life‐history patterns and estimating secondary production. Total psephenid annual production over the period 1977–79 was 930–5 mg AFDW (ash‐free dry weight) 0.5 m‐2, but was more than twice as high in 1977–78 (1381–6mg AFDW 0.5m‐2) than in 1978–79 (562.6mg AFDW 0.5m‐2). Sinopsephenus chinensis and Eubrianax sp. were the most abundant psephenids in TPKFS, but the larger S. chinensis contributed most to total psephenid secondary production. Eubrianax sp. made the second largest contribution to production, while the contribution of the two remaining species (Psephenoides sp. and Mataeopsephus sp.) was minor. Eubrianax sp. production was generally constant between years, but production (and population densities) of the other three psephenids declined in 1978–79. Sinopsephenus chinensis was clearly bivoltine in TPKFS, but Eubrianax sp. and Psephenoides sp. showed asynchronous growth and almost continuous recruitment. Accurate estimates of production: biomass ratio (P: B) ratio were possible for S. chinensis only, and varied between 12.8 and 19.4 over the two years of the study. Eubrianax sp. and (especially) S. chinensis were most abundant in midstream microhabitats but Psephenoides sp. was more numerous close to the stream banks. Mataeopsephus sp. was relatively rare and lacked an obvious microdistribution pattern. Multivariate statistics (principal components analysis followed by multiple regression) were used to investigate the relationship between psephenid densities in each benthic sample and the sediment characteristics, detrital standing stocks and algal biomass in the environment where the sample was taken. The analysis revealed that psephenid microdistribution was influenced by sediment grain‐size characteristics rather than by algae or detritus, but the proportion of variation in the abundance of psephenid species accounted for by sediment characteristics was rather low.
Thermoregulation and metabolism in the Cape golden mole (Insectivora: Chrysochloris asiatica)
Authors: Bennett N. C. , Spinks A. C. 
Published: March 2009

The Cape golden mole, Chrysochloris asiatica is an insectivore which excavates superficial foraging burrows as it searches for its food. It has a mean (±S.D.) resting metabolic rate (RMR) when newly captured of 1–17±0.17 cm3 O2g‐1 h‐1 (n= 14), within the thermoneutral zone (TNZ) of 30–32°C.The body temperature (Tb) of the mole in the TNZ is low 32.9 ± 0.36 (n= 14) and remains stable at ambient temperatures (Tas) from 28–32°C. Above 32°C (range 34–37°C), Tb increases albeit slightly to 36 ± 1.75°C (n= 14). The conductance is high 0.27 ± 006cm3 O2g‐1 h‐l°C‐1 (n= 46) at the lower limit of thermoneutrality. The mean RMR at 9°C (the lowest Ta tested) was 4.82±11 cm3 O2g‐1h‐1, which is 4.1 times that of the RMR in the TNZ.At an ambient temperature of 9°C, three of the golden moles entered a state of torpor where the RMR was reduced from 5.9±0.56 to 10 1.0 ± 0.69cm3O2g‐1h‐1.