bluuebunny/crossref_metadata_2025 huggingface dataset:
Vocal repertoire of South American fur seals, Arctocephalus australis: structure, function, and context
Authors: Phillips Alana V , Stirling Ian
Published: April 2011

We describe the vocal repertoire of male and female South American fur seals (Arctocephalus australis) breeding at Punta San Juan, Peru, the first such description for any member of the genus. We distinguished 11 call types, which we grouped into four functional classes: investigative, threat, submissive, and affiliative calls. Barking is used during non-agonistic investigation of other individuals. Threat calls of South American fur seals show gradation of structure, form, and apparent meaning, and are grouped into two series: nontonal or respiratory sounds, and pulsed or guttural sounds that sometimes include a terminal tonal component. This might be adaptive in enabling display behavior to be flexible in agonistic situations, allowing participants to interpret situations on the basis of contextual cues and their own physical ability and experience. In contrast, vocal displays such as submissive, full-threat, and affiliative calls tend to have a discrete acoustic structure. Of these, full-threat, female-attraction, and pup-attraction calls share acoustic characteristics: all are long, loud calls composed of both pulsed and tonal components, and show sufficient variation to allow individual recognition. We attempt to establish a base line for standardizing nomenclature and acoustic analysis, to facilitate further comparative research on the vocal repertoire of Arctocephalus species.
Resighting and association patterns of bottlenose dolphins (Tursiops truncatus) in the Cedar Keys, Florida: insights into social organization
Authors: Quintana-Rizzo Ester , Wells Randall S
Published: April 2011

Little is known about the social organization of bottlenose dolphins (Tursiops truncatus) inhabiting open estuarine systems. Our purpose was to identify and quantify the resightings of bottlenose dolphins and associations formed among them to provide insights into the social organization of the species in the open estuarine system of the Cedar Keys, Florida. We conducted monthly photographic-identification surveys from June 1996 through May 1997. We identified a total of 233 dolphins of which 217 (93%) were classified into one of four categories based on the number of months in which they were sighted. "Rare" dolphins (sighted during 12 months) constituted more than half of these individuals (61%), followed by "occasional" (35 months; 20%), "common" (>8 months; 12%), and "frequent" (56 months; 7%) dolphins. We quantified the associations for dolphins sighted 10 times (26 common, 12 frequent, and 8 occasional) and found that individuals with different resighting patterns associate with each other but the association is mostly at a low level. The level of association among common dolphins, however, was higher within than between the sexes. Association patterns of common dolphins in the Cedar Keys resemble the associations of resident bottlenose dolphins inhabiting closed estuarine bays, suggesting that the selective pressures which induce such associations are the same in these aquatic systems.
Influence of food shortage during the summer on body composition and reproductive hormones in the red fox, Vulpes vulpes
Authors: Larivière Serge , Crête Michel , Huot Jean , Patenaude Robert , Price Christopher , Thomas Donald W
Published: April 2011

Some mammalian carnivores compensate for prey shortage during the summer by increasing their consumption of wild berries. We tested whether such prey shortage affected all body components (e.g., fat, protein, water) equally, and whether it could affect reproduction. Two groups of wild red foxes (Vulpes vulpes) were kept in captivity: the first group was fed a control diet of dog food, and the second group was fed a diet of dog food and fresh apples for 8 weeks during midsummer. The experimental diet contained 95% of the energy content of the control diet but only 55% of the protein and 46% of the fat content. Foxes fed the experimental diet simultaneously lost body fat and protein on the apple diet, but body reserves were quickly restored upon return to the control diet. We found no evidence that protein and energy deficiency during summer impaired reproduction the following spring.
Male lizards change their genital skin almost every day: squamate pan-epidermal synchrony refuted
Authors: in den Bosch Herman AJ
Published: April 2011

Lacertid lizards frequently shed the outer layers of the epidermis of the paired male intromittent organs, the hemipenes. The hemipenial sloughs so formed are saclike and reproduce all the external features of the hemipenes in great detail. Sloughs are deposited immediately after the first defecation of the day and are produced almost every morning during the breeding season. I have observed these in 48 lacertid species, including members of the genera Acanthodactylus, Adolfus, Algyroides, Gallotia, Holaspis, Lacerta s.l., Latastia, Podarcis, Psammodromus, and Takydromus. As these forms represent all three subfamilies of the Lacertidae, the phenomenon is likely to have been present in the common ancestor of the family. It may even be a general squamate feature, as it has also been observed in the distantly related varanid Varanus acanthurus. Frequent shedding of hemipenial sloughs violates pan-epidermal synchrony, the belief that the epidermis of squamates is shed simultaneously over all parts of the body, and indicates that the hemipenial epidermis is under different hormonal control from the rest of the skin. The function of frequent shedding of the hemipenial epidermis is not known for certain, but there is a wide range of possible hypotheses. Some of these are involved in increasing the efficiency of copulation and ameliorating its costs, while others emphasise the possible signalling function of the hemipenial sloughs.
Phylogeny of the genus Scathophaga (Diptera: Scathophagidae) inferred from mitochondrial DNA sequences
Authors: Bernasconi M V , Pawlowski J , Valsangiacomo C , Piffaretti J -C , Ward P I
Published: April 2011

Scathophaga stercoraria has been used for a large number of studies in animal ecology and evolution. Morphological phylogenetic work on the relationships among flies of the family Scathophagidae in general, and the genus Scathophaga in particular, has led to limited or incomplete conclusions. We addressed these relationships by sequencing 810 base pairs (bp) from the mitochondrial cytochrome oxidase subunit I (COI) gene and 738 bp of the mitochondrial cytochrome b (Cyt b) gene in 16 species of Scathophagidae. Phylogenetic analysis of these two protein-coding genes allows us to resolve relatively well the relationships within the genus Scathophaga, using both separate and combined (COI + Cyt b) data. Most of the phylogenetic trees generated by our data support the following relationships: (((S. analis + S. inquinata) + S. lutaria) + S. cineraria + (S. taeniopa + S. suilla + S. incola) + S. furcata + S. tropicalis). The most noteworthy findings are that (i) S. obscura and S. tinctinervis, which were formerly placed in the genus Coniosternum, form a sibling species cluster; (ii) S. taeniopa and S. suilla, which are morphologically very similar species, are clearly distinct taxa; (iii) S. analis, considered a doubtful species in the Catalogue of Palearctic Diptera, could be a synonym of S. inquinata; and (iv) the South American S. tropicalis and the Old World S. stercoraria are not sister-species.
Development of the tentacles and food groove in the jellyfish Aurelia aurita (Cnidaria: Scyphozoa)
Authors: Chapman David M
Published: April 2011

The development of the tentacle-bearing part of the rim of the jellyfish Aurelia aurita is described. The newly liberated ephyra lacks appendages at the bell rim between the rhopalial arms (null stage). The next stage (bump stage) has a subumbrellar bump near the rim. The bump then forms a tongue process (tongue stage) on its adoral side. The aboral part of the bump becomes the primordium of the tentacle. The tongue process elongates and spreads circumferentially, finally melding with the lappets of the rhopalial arms. Next the tongue process develops a groove that spreads laterally. The epithelium of the groove becomes glandular and serves as a food groove where particulate matter such as plankton is concentrated and undergoes the initial phase of digestion. The "upper" side of the split tongue process becomes the floor of the tentacle chambers, while the "lower" side becomes the pseudovelarium. The growth and differentiation zone for the medusa's rim is at the junction of the tentaculate part of the rim with the rhopalial region. It is here that tentacle buds form, followed by intertentacular lappets (partitions).
Survival in adults of the water frogRana lessonaeand its hybridogenetic associateRana esculenta
Authors: Peter Anna-Katherina Holenweg
Published: April 2011

Using recent developments in capturemarkrecapture modelling, I analysed survival rates of adults of two species of water frogs, the parent species Rana lessonae and its sexual parasite, the hybrid Rana esculenta. Frogs were caught in four different breeding ponds between 1995 and 1998 and the effects of genotype (= species), sex, pond, and time on survival rates and recapture probabilities were tested. Survival rates were consistently higher in R. lessonae than in R. esculenta. Recapture probability was higher in males than in females. In both species, survival rates were constant during spring and summer and similar in all years of the investigation, average monthly survival rates being lower than those during autumn and winter. The variation in annual survival rates (7284% for R. lessonae and 5370% for R. esculenta) is probably caused by differences in winter survival rates. Capturemarkrecapture models cannot separate mortality and emigration and hence usually underestimate survival rates. To eliminate this source of error, I quantified emigration, which ranged from 0 to 29% at the four ponds. After correcting for these emigration rates, I found no differences in survival rates among the four ponds. The overall high survival rates of adult R. lessonae compared with R. esculenta partially compensate for the hybrid's initial reproductive advantage in terms of mating, fertility, and larval development and, hence, contribute to stabilising mixed populations.
Subversion of alarm communication: Do plants habituate aphids to their own alarm signals?
Authors: Petrescu Anca S , Mondor Edward B , Roitberg Bernard D
Published: April 2011

When attacked by a predator, pea aphids, Acyrthosiphon pisum, emit an alarm pheromone, (E)-β-farnesene, which causes nearby conspecifics to disperse from the area. However, herbivore-damaged plants also emit (E)-β-farnesene. We hypothesized that plants release farnesene to habituate aphids, i.e., to disrupt their alarm-pheromone responses, perhaps to reduce herbivory by increasing parasitoid or predator efficacy. Thus, we addressed two questions: (1) Do aphids habituate to (E)-β-farnesene, and (2) Are they habituated at levels produced by aphid-infested plants? On an artificial diet devoid of farnesene, aphids were exposed to 10 ng/cm3 of (E)-β-farnesene or a hexane control over 24 h. Habituation was achieved, as dropping responses to 50 ng/cm3 of (E)-β-farnesene decreased after exposure. We then exposed aphids to 0.8 ng/cm3 of (E)-β-farnesene, a pheromone concentration emitted by plants, or a hexane control for 24 h. Their reaction to 38 ng/cm3 of (E)-β-farnesene, the maximum pheromone concentration found in aphid-cornicle droplets, was not significantly different before and after exposure. Thus, our hypothesis that plants emit farnesene to disrupt aphid alarm communication remains unsupported.
Delineating Canadian and Greenland polar bear (Ursus maritimus) populations by cluster analysis of movements
Authors: Taylor Mitchell K , Akeeagok Seeglook , Andriashek Dennis , Barbour William , Born Erik W , Calvert Wendy , Cluff H Dean , Ferguson Steve , Laake Jeff , Rosing-Asvid Aqqalu , Stirling Ian , Messier François
Published: April 2011

Within their circumpolar range, polar bears (Ursus maritimus) are not subject to absolute barriers. However, physiographic features do cause discontinuities in their movements. These discontinuities in distribution can be used to delineate population units. Based on satellite telemetry of the movements of female polar bears carried out in 19891998, we used cluster analysis to identify 6 regions within the Canadian and western Greenland Arctic in which movements appear to be restricted enough to identify distinct populations. These regions generally correspond to management units that have been previously identified as Viscount Melville Sound, Lancaster Sound, Norwegian Bay, Kane Basin, Baffin Bay, and Davis Strait. A northsouth substructure was identified for the Baffin Bay population, but it was weaker than the structure identified for the 6 primary units. The 6 units were consistent with genetic information, except for the Baffin Bay  Kane Basin separation, and with markrecapture observations and the traditional knowledge of Inuit hunters. Only 2 of 65 bears that provided telemetry information for more than 1 year were classified in different populations in different years. However, annual rates of exchange, measured as the percentage of locations outside the population boundary, ranged from 0.4 to 8.9%. Analysis of markrecapture movements indicated no difference in large-scale movements between the sexes or long-term movements with age. Although our validation criteria for demographic closure were satisfied, the observed rates of exchange between adjacent populations suggest that population dynamics in adjacent populations may not be completely independent.
On understanding variation in immune expression of the damselflies Lestes spp.
Authors: Yourth C P , Forbes M R , Smith B P
Published: April 2011

Immune ability and immune expression have been viewed as life-history traits that are influenced by such factors as the likelihood of being parasitized, intensity and costs of parasitism, and trade-offs associated with immune expression. In this paper we show that different patterns of infestation by a generalist ectoparasite, Arrenurus planus Marshall (Arrenuridae: Hydrachnida), do not fully explain the variation in immune expression across four species of sympatric damselflies (Lestidae: Zygoptera). Within species, no gender biases in immune expression were evident. Whereas both males and females of one oft-exploited species did not mount immune responses against attending larval mites, males and females of three other species showed similar immune responses, with variable expression. The immune response was melanotic encapsulation of mite feeding tubes, and was associated with dead mites. Of the three species showing immune expression, the species with the highest prevalence and intensity of infestation had a significantly higher proportion of individuals responding immunologically to mites. In conclusion, current infestation levels only partially predict immune investment; consideration of the timing of emergence of different species suggests that season may be an important predictor of immune investment.
Omnivorous lacertid lizards (Gallotia) from El Hierro, Canary Islands, can identify prey and plant food using only chemical cues
Authors: Cooper, Jr. William E , Pérez-Mellado Valentín
Published: April 2011

We studied lingual and biting responses to food chemicals by two species of omnivorous lacertid lizards, the Canary Island endemics Gallotia simonyi (the giant lizard of El Hierro) and Gallotia caesaris (Boettger's lizard), to ascertain their ability to discriminate between prey and plant food chemicals on the one hand and control stimuli on the other. We recorded frequencies of tongue-flicking and latency to bite in 60-s trials in which chemical stimuli on cotton-tipped applicators were presented to the lizards. Both species exhibited prey-chemical discrimination, as indicated by elevated tongue-flick rates and higher proportions of individuals biting in response to surface chemicals from crickets. Both species exhibited plant-chemical discrimination, as indicated by significantly greater tongue-flick rates and biting frequency in response to chemicals from tomato fruit than to the control stimuli. Juvenile G. simonyi responded much more strongly to chemical stimuli from tomato fruit than from leaves of Psoralea bituminosa, which is not a preferred food for juveniles. The findings are consistent with the hypothesis that chemosensory discrimination evolves in omnivorous lizards to permit evaluation of food quality, resulting in correspondence between plant diet and plant-chemical discrimination, both being absent in insectivores. The results are also consistent with the hypothesis that prey-chemical discrimination is retained and plant-chemical discrimination evolves in the omnivorous lizards derived from actively foraging insectivores.
Territorial defense by coyotes (Canis latrans) in Yellowstone National Park, Wyoming: who, how, where, when, and why
Authors: Gese Eric M
Published: April 2011

Territorial defense and maintenance are an important facet of the social ecology of most carnivore species. From January 1991 to June 1993, we observed 54 coyotes (Canis latrans) for 2507 h in Yellowstone National Park, Wyoming, during which we observed 112 instances of territory defense. The identity of the coyotes involved in challenging and evicting intruding animals was known. Alpha coyotes were most likely to be involved in territorial evictions of intruding animals, followed by beta individuals; pups participated little in territory defense. Coyotes evicting intruders generally had a numerical advantage when challenging the intruders. Territory-defense rates were highest during and immediately after the breeding season and during the time of pup emergence from the den. All chases of intruders ended at the boundary of the resident coyote pack's territory. Physical contact between the intruding animal and resident pack members occurred with no intruders being killed or seriously injured. Physical contact consisted of fighting and ritualized behaviors, with only a few instances in which fighting led to blood being drawn or minor injuries to the intruder. Most encounters resulted in a hasty retreat from the area by the intruder(s). While indirect means of territory maintenance (i.e., howling and scent-marking) were utilized by resident packs, trespassing still occurred and direct confrontation was needed to enforce boundaries and assert occupancy against other resident packs, as well as against lone intruders seeking territory vacancies. Territoriality was advantageous in that territory holders generally had higher survival rates (except pups), contributed all the reproductive effort to the population, and had greater access to food resources. In contrast, nonterritorial animals had lower survival rates, did not breed, and had reduced access to food (ungulate carcasses) during winter.
Mechanisms of truffle detection by northern flying squirrels
Authors: Pyare Sanjay , Longland William S
Published: April 2011

The objective of this study was to evaluate how northern flying squirrels (Glaucomys sabrinus) locate truffles (Gautieria monticola), a subterranean and ephemeral but primary food source. Thus, we evaluated the importance of three factors to the foraging behavior of northern flying squirrels: (i) olfactory chemicals that emanate from truffles; (ii) the presence of coarse woody debris (decaying logs), which are often associated with fungi; and (iii) we explored the potential role animal memory could play in truffle detection as well. In a foraging arena, squirrels successfully retrieved buried truffles that lacked aboveground cues in 19 of 30 trials and failed to search near treatments that lacked truffles altogether, confirming the importance of olfaction to squirrel foraging. However, squirrels also retrieved truffles that were associated most frequently with surface logs (27 of 30). In addition, the initial detection rate of the truffle + log treatment was significantly greater than the truffle-only treatment. Thus, although squirrels search for truffles primarily using olfaction, they may also benefit by searching near coarse woody debris on the forest floor as an aboveground cue to truffle locations. In addition, because 82% of Sierra Nevada truffle-fruiting locations that were marked in 1996 yielded truffles again the following 2 years, mycophagous animals like northern flying squirrels may benefit by memorizing fruiting locations and foraging at these same locations from year to year.
Evaluating body condition in small mammals
Authors: Schulte-Hostedde A I , Millar J S , Hickling G J
Published: April 2011

Body condition (energy reserves) can have important fitness consequences. Measuring condition of live animals is typically done by regressing body mass on measures of body size and using the residuals as an index of condition. The validity of this condition index was evaluated by determining whether it reflected measured fat content of five species of small mammals (yellow-pine chipmunks (Tamias amoenus Allen), bushy-tailed wood rats (Neotoma cinerea Ord), deer mice (Peromyscus maniculatus Ord), red-backed voles (Clethrionomys gapperi Vigors), and meadow voles (Microtus pennsylvanicus Ord)). We also determined whether body water could predict fat content, enabling the use of hydrogen-isotope dilution for estimating condition. For all five species, condition estimates weakly predicted fat content and more accurately predicted variation in lean dry mass and water content. The relationship between body water and fat content was inconsistent among the five species, discouraging against the general use of isotope dilution in these animals. Although ecologically important, these indices are best interpreted as explaining variation in all constituents of body composition.
Population biology of eyeflukes in fish from a large fluvial ecosystem: the importance of gulls and habitat characteristics
Authors: Marcogliese D J , Compagna S , Bergeron E , McLaughlin J D
Published: April 2011

Spottail shiners (Notropis hudsonius) were monitored for eyeflukes monthly at four sites in the St. Lawrence River, Quebec, from spring through autumn in 1997 and 1998. In general, mean abundance of Diplostomum spp. in the lens of spottail shiners was highest at sites near large ring-billed gull (Larus delawarensis) colonies and was higher in 1998 than in 1997. Population studies demonstrated a major period of recruitment in the late summer  early autumn. Mean abundance increased between November and May, when sampling was logistically not possible, reflecting late-fall or early-spring recruitment. Golden shiners (Notemigonus crysoleucas) and small yellow perch (Perca flavescens) were monitored at a single site (Île aux Ours) in 1997 and 1998. Mean abundance of Diplostomum spp. in the lens of golden shiners at Île aux Ours was higher in 1998 than in 1997. Recruitment occurred in the early summer and between November and May, suggesting late-fall or early-spring transmission. Mean abundance decreased between August and October in both years. Yellow perch at Île aux Ours were infected with four different parasite species in their eyes. Mean abundance of Diplostomum spp. in the vitreous humour or retina increased during the summer and fall and then decreased between the fall and following spring. Diplostomum spp. in the lens increased in abundance in the early summer, and then decreased during the fall. Both Tylodelphys scheuringi and Neascus spp. in the vitreous humour were more abundant in 0+ than in 1+ perch. Mean abundance of T. scheuringi increased over the summer in 1997 and then dropped to zero in the same cohort over winter, suggesting that the parasite lives for only 1 year. Neascus spp. only were found in 1998. Distributional data, together with seasonal information, suggest that habitat characteristics contribute significantly to the abundance of Diplostomum spp. along the St. Lawrence River. Proximity to gull colonies enhances abundance, but higher rates of predation at wetland sites depress abundance and restrict the accumulation of parasites.
Microgeographic variation in allozymes and mitochondrial DNA ofMicrotus richardsoni, the water vole, in the Beartooth Mountains of Montana and Wyoming, U.S.A.
Authors: Klaus Marion , Moore Robert E , Vyse Ernest
Published: April 2011

Microtus richardsoni, the water vole, is listed as a sensitive species within region 2 of the USDA Forest Service. Because it is a sensitive species, the water vole's ability to disperse becomes an important management concern in terms of its population viability. Both allozyme and mitochondrial DNA analyses were used to study microgeographic population structure within a group of populations from four adjacent watersheds of the Beartooth Mountains of Montana and Wyoming. Of 31 protein loci examined, only ADH, EST-1, and SOD-1 were polymorphic. ADH and EST-1 were in HardyWeinberg equilibrium, but SOD-1 was not. Mitochondrial DNA was found to be polymorphic with 9 restriction enzymes. The size of the fragments produced by each restriction enzyme was estimated and ordered into a site map. In total, 51 sites were found with 9 restriction enzymes resulting in 29 different haplotypes from 142 individuals. Shared haplotypes were geographically contiguous except for one. There was no significant difference in genetic distance among water voles from the Beartooth Mountains, and only the outgroup from Togwotee Pass in the Absaroka Mountains of Wyoming had significant genetic distance. This suggests the possibility of dispersal between water voles from the contiguous watersheds of the Beartooth Mountains but not between the Beartooth Mountains and Togwotee Pass populations.
Enzyme activities and morphology of Japanese brown frog (Rana japonica) mitochondria in the tibialis anterior muscle during hibernation and active life
Authors: Sato Iwao , Konishi Kiyoshi , Sunohara Masataka , Mikami Akiko
Published: April 2011

Enzyme activities in the respiratory chain, as well as the structure and numbers of mitochondria of the tibialis anterior muscle, during hibernation were compared with those of normally active muscle in the Japanese brown frog (Rana japonica). Morphological examination using an electron microscope showed that during hibernation, mitochondria were larger and longer and had clearly distinguishable outer and inner membranes with developed cristae. A significantly greater number of glycogen granules was found in the tibialis anterior muscle of hibernating frogs. The average cross-sectional area (CSA) of muscle fiber was much smaller in the samples from hibernating frogs than those from active frogs. The numbers of mitochondria per CSA were also much higher during hibernation than during active life. Measurements of the enzyme activities of succinate dehydrogenase, NADH-ferricyanide reductase, and succinate-O2and NADH-O2oxidoreductases showed different profiles between hibernation and active life. That is, all four activities were significantly higher during hibernation than during active life. Taken together, the results obtained suggest that the seasonal variations in the activities of respiratory-chain systems may be related to the seasonal morphological changes in muscle mitochondria in R. japonica.
Test of the prey-base hypothesis to explain use of red squirrel midden sites by American martens
Authors: Pearson Dean E , Ruggiero Leonard F
Published: April 2011

We tested the prey-base hypothesis to determine whether selection of red squirrel (Tamiasciurus hudsonicus) midden sites (cone caches) by American martens (Martes americana) for resting and denning could be attributed to greater abundance of small-mammal prey. Five years of livetrapping at 180 sampling stations in 2 drainages showed that small mammals, particularly red-backed voles (Clethrionomys gapperi) and shrews (Sorex spp.), were more abundant at midden sites than at non-midden sites. However, logistic regression indicated that middens occurred in sprucefir (Picea engelmannii  Abies lasiocarpa) stands, being correlated with decreasing lodgepole pine (Pinus contorta) basal area, decreasing distance to water, and increasing canopy cover. Since middens were not randomly distributed, we constructed multiple linear regression models to determine the variability in small-mammal abundance and species richness attributable to structural and landscape variables. Regression models indicated that abundance of small mammals, red-backed voles, and uncommon small mammals could be predicted from structural and landscape variables, but midden presence did not significantly improve these models. Midden presence was a significant but weak predictor of small-mammal species richness. Our data do not support the prey-base hypothesis for explaining martens' selection of resting and denning sites near red squirrel middens at the scales we tested.
Diet of northern bottlenose whales inferred from fatty-acid and stable-isotope analyses of biopsy samples
Authors: Hooker Sascha K , Iverson Sara J , Ostrom Peggy , Smith Sean C
Published: April 2011

The Gully submarine canyon off eastern Canada has been designated a pilot marine protected area largely because of the northern bottlenose whales (Hyperoodon ampullatus) found there. Studies of this species' diet elsewhere in the North Atlantic Ocean have suggested specialization on the deep-sea squid Gonatus fabricii. We found a high proportion of the congener Gonatus steenstrupi in the stomachs of two bottlenose whales stranded in eastern Canada. In 1997, we collected remote biopsy samples from free-ranging bottlenose whales off Nova Scotia; fatty acids were determined from blubber samples and stable isotopes (carbon and nitrogen) from skin samples. Although fatty-acid stratification throughout the depth of the blubber layer was present (determined from blubber samples of stranded animals), the magnitude of stratification was less pronounced than in many other cetaceans, allowing some qualitative inferences to be made from shallow biopsy samples. Fatty-acid patterns and stable-isotope values from whales were compared with those in samples of G. fabricii from the Norwegian Sea. Blubber fatty acid composition was similar in characteristics to that of adult G. fabricii but was markedly distinct from that of juvenile G. fabricii and other recorded prey species. Nitrogen-isotope values implied that bottlenose whales (mean 15.3) and adult G. fabricii (mean 13.7) occupy high trophic levels. Overall, the results of these techniques concurred in suggesting that squid of the genus Gonatus may form a major part of the diet of bottlenose whales in the Gully.
Spacing behaviour, kinship, and population dynamics of grey squirrels in a newly colonized broadleaf woodland in Italy
Authors: Gurnell John , Wauters Luc A , Preatoni Damiano , Tosi Guido
Published: April 2011

Eastern grey squirrels, Sciurus carolinensis, introduced to Britain and northern Italy are replacing the native Eurasian red squirrel, Sciurus vulgaris. We studied the pattern of colonization of a high-quality broadleaf woodland by grey squirrels by means of livetrapping and radio-tracking. The studies started in July 1996, when six grey squirrels (four males, two females) first colonized the woodland, and lasted until November 1998, when densities exceeded those of the local red squirrel population. Grey squirrel colonization was rapid, with a high proportion of adult and yearling females breeding. Juvenile recruitment was also higher than in stable populations in Britain. Adult survival was better in 1997 (83%) than in 1998 (47%), with predation accounting for 67% of losses in 1998. This indicates the effects of local predator communities on the colonization process. Densities of grey squirrels were moderate in 1998, with a maximum of 1.9 squirrels/ha and we expect density to increase further. Adult home range sizes were three to four times larger than those of subadults, and male ranges were larger than those of females. Body mass was positively correlated with both total home range size and core-area size. Core-area size for adults was inversely correlated with food availability. Juvenile female grey squirrels were philopatric, forming female kin groups, while most juvenile males settled outside the mother's home range.
Space-use patterns by female striped skunks exposed to aggregations of simulated duck nests
Authors: Larivière Serge , Messier François
Published: April 2011

We monitored space-use patterns and behaviour of female striped skunks (Mephitis mephitis) during the spring and summer of 1995 simultaneously with the deployment of simulated duck nests (2.525/ha) in Saskatchewan, Canada. In 1995, home ranges of five female skunks averaged 2.3 km2 (SE = 0.5 km2), which was smaller (P = 0.01) than home ranges of females (n = 21) present in the same area in 19931994. Home-range overlap did not differ (P = 0.34) between 19931994 (71 ± 4%) and 1995 (75 ± 11%). Female skunks were nocturnal during all years, but were less active in 1995 than in 19931994 (P < 0.01). Patterns of habitat selection differed during the nest experiment: managed waterfowl-nesting areas were used less than wetlands in 19931994, but no significant difference in use of these two habitats was detected in 1995. Although we cannot ascertain a direct cause-and-effect relationship, owing to a possible year effect, the changes in space-use patterns of striped skunks exposed to aggregations of simulated nests are consistent with the literature on food-supplementation experiments. These results re-emphasize the importance of food in determining the space-use patterns of striped skunks.
The effects of constant and fluctuating incubation temperatures on sex determination, growth, and performance in the tortoiseGopherus polyphemus
Authors: Demuth Jeffery P
Published: April 2011

Temperature-dependent sex determination is one of the best documented yet evolutionarily enigmatic sex-determining systems. The classical theoretical framework suggests that temperature-dependent sex determination will be adaptive when males and females benefit differentially from development at certain temperatures. Empirical evidence has not provided convincing support for this "differential-fitness" hypothesis. Furthermore, since most experiments utilize constant temperature incubation treatments to explore phenotypic response to temperature, few studies have addressed the consequences of incubation under natural conditions. In this study I utilized constant-temperature laboratory incubations and natural-nest incubations to determine the effects of temperature on sex, size, growth, and locomotor performance in the tortoise Gopherus polyphemus. Constant-temperature incubations do induce substantial growth and performance variation in these tortoises. However, the data do not clearly support the differential-fitness hypothesis because (i) growth variation does not result in adult size dimorphism, (ii) performance differences are confined to a very short period after hatching, and (iii) natural incubation temperatures do not vary sufficiently to produce significant phenotypic variation in traits other than sex.
Phylogenetic relationships among megachiropteran species from the two major islands of the Philippines, deduced from DNA sequences of the cytochrome b gene
Authors: Bastian, Jr. Severo T , Tanaka Kazuaki , Anunciado Rea Victoria P , Natural Nelson G , Sumalde Augusto C , Namikawa Takao
Published: April 2011

Complete cytochrome b gene sequences (1140 base pairs) in species of Megachiroptera were ascertained in order to deduce their phylogenetic relationships, using samples of Cynopterus brachyotis, Eonycteris spelaea, Ptenochirus jagori, Pteropus vampyrus, and Rousettus amplexicaudatus collected from the islands of Luzon and Mindanao in the Philippines. Genetic divergence between samples of R. amplexicaudatus, E. spelaea, and C. brachyotis was very small. On the other hand, a large genetic distance was detected between species of Megachiroptera. The phylogenetic tree using neighbor-joining, parsimony, and maximum-likelihood methods generated similar topologies, reflecting the evolutionary associations among megachiropteran species. We estimated that Megachiroptera separated from Microchiroptera 50.2 million years ago (MYA), and split further approximately 32.4 MYA, forming three lineages: E. spelaea, R. amplexicaudatus, and P. vampyrus and the P. jagori  C. brachyotis cluster. The third lineage, composed of P. vampyrus and the P. jagori  C. brachyotis cluster, branched out 31.9 MYA. We hypothesize that R. amplexi caudatus diverged from the three members of the subfamily Pteropodinae examined, and its phylogenetic relationship with E. spelaea remains unclear.
Male phenotype and sperm number in the guppy (Poecilia reticulata)
Authors: Pitcher Trevor E , Evans Jonathan P
Published: April 2011

The idea that female mate choice might be adaptive is relatively easy to understand in species with resource-based mating systems in which females gain access to a territory, food, or other forms of parental care from the males with whom they mate. In contrast, the evolution of female mate choice in species exhibiting resource-free mating systems remains controversial. One such species in which males contribute nothing but sperm during mating is the guppy (Poecilia reticulata). Here, we examined whether female guppies can obtain information on male fertility (i.e., direct fertility benefits) via cues used during mate choice. Specifically, we examined whether male guppy colour patterns, body size, and mating behaviour signal their functional fertility, that is, their ability to supply a large number of sperm at copulation. We found significant correlations between male phenotype parameters and the number of sperm in male guppies originating from two wild Trinidadian populations. There were, however, significant interpopulation differences with respect to which traits were good predictors of sperm load. In the low-predation Paria River population, larger males and males with relatively more carotenoid colouration had significantly larger sperm loads, but mating behaviour (i.e., sigmoids) and melanin colouration were not good predictors of sperm load. In the high-predation Tacarigua River population, larger males, males that displayed more, and males with less yellow colouration had significantly more sperm, but other colour pattern components (area of orange and black colouration) were not good predictors of sperm load. Overall, our results suggest that there is the potential for direct fertility benefits through mate choice in the promiscuous, non-resource-based mating system of the guppy.
Using caddisfly (Trichoptera) case-building behaviour in higher level phylogeny reconstruction
Authors: Stuart Alison E , Currie Douglas C
Published: April 2011

Higher level phylogenetic analyses rarely include behavioural data, predominantly because such groups seldom have complex behaviours that are susceptible to analysis. Even when broad groups do share a complex behaviour, there is skepticism about the appropriateness of using behavioural traits in higher level phylogenetic analyses. The Integripalpia is a suborder of caddisflies and is an appropriate group to investigate the use of behaviour in higher level analyses because all larvae use a complex suite of behaviours to build portable cases. A thorough investigation of case-building in 10 families (19 exemplar genera) yielded 24 behavioural characters. A parsimony analysis produced 87 equally parsimonious trees (length = 56 steps, consistency index (CI) = 0.84, retention index (RI) = 0.88) that supported the monophyly of the integripalpian families, except for the Limnephilidae. Interfamilial relationships, although resolved, were not well supported with behaviour. Certain interfamilial relationships have also been difficult to establish reliably with morphological information, indicating a need for more characters (e.g., molecular) at this taxonomic level. This study indicates that if taxa share a complex behaviour (e.g., case building), then regardless of taxonomic level, one is likely to find shared derived behavioural characters that are useful for phylogeny reconstruction.
Seasonal decline in health status of Great Tit (Parus major) nestlings
Authors: Dubiec Anna , Cichoñ Mariusz
Published: April 2011

Seasonal variation in offspring survival and recruitment rates in birds may be mediated by immune function, as it defines the ability of individuals to protect themselves against parasites and infectious diseases. To investigate the relationship between hatching date and health status of Great Tit (Parus major) nestlings, two blood parameters (leukocyte level and haematocrit) were estimated. Leukocyte level decreased as the season progressed within first but not second broods, while haematocrit showed no seasonal variation within either brood type. However, nestlings from first broods had both higher leukocyte levels and higher haematocrit than nestlings from second broods. Nestling body condition (defined as the residual of body mass on tarsus length calculated from linear regression) was not related to hatching date within brood type, while a significant difference between brood types was found. We suggest that the commonly observed decline in juvenile survival rate as the season progresses may be at least partly attributed to seasonal changes in health status.
Spatial structure of harbour seal populations and the implications thereof
Authors: Härkönen T , Harding K C
Published: April 2011

A long-term study of freeze-branded harbour seals (Phoca vitulina) revealed explicit site fidelity. Individuals were followed up to 14 years of age and none of the 163 branded animals were observed to haul out beyond a 32-km distance from the site where they were branded as pups. Within this range, striking spatial segregation by age and sex prevailed. While females' site fidelity increased with age, males spent less time at their natal site with increasing age. These findings have consequences for understanding the population dynamics of harbour seals, since single "colonies" will act as partly isolated "subpopulations" in some contexts but not in others. The differing migration tendencies of the population segments lead to spatially segregated sex and age ratios of subpopulations and create a complex pattern of connectivity among these subpopulations. Ignoring the spatial scale will lead to severe misinterpretations of analyses of basic population-dynamic processes, especially rates of population increase, rates of gene flow, and the dynamics of the spread of diseases. We suggest that when studies have different aims, these should be addressed by encompassing different numbers of subpopulations.
Twenty-four-hour feeding and lying patterns of wild reindeer Rangifer tarandus tarandus in summer
Authors: Colman Jonathan E , Pedersen Christian , Hjermann Dag Ø. , Holand Øystein , Moe Stein R , Reimers Eigil
Published: April 2011

We tested whether sunlight and insect harassment were important proximate factors (Zeitgebers) controlling feeding and lying patterns of wild reindeer (Rangifer tarandus tarandus) in summer. With no insect harassment, feeding and lying each exhibited a polycyclic rhythm with, on average, 4 bouts at equal intervals during each 24-h period (unit-sum constraints in a polycyclic rhythm). When insects were absent, the activity percentages were 50 ± 4% feeding (mean ± SE) and 33 ± 4% lying for daytime and 44 ± 3% feeding and 47 ± 4% lying for nighttime, i.e., the percentage of time spent feeding was equal for daytime and nighttime (nychthemeral), while for lying it was not. With insects present, percentages of time spent feeding and lying were 18 ± 3 and 13 ± 3% for daytime and 45 ± 8 and 41 ± 8% for nighttime, respectively, i.e., neither feeding nor lying exhibited a nychthemeral pattern. During periods of insect harassment, 24-h feeding patterns had no cyclic rhythm, whereas lying remained cyclic, but the percentages of time spent lying during peak bouts (amplitude) and at peak duration (period) were unequal between night and day. Reindeer did not attune their activity to the set points of sunrise and sunset (not crepuscular), demonstrating that daylight is most likely not a powerful Zeitgeber for reindeer during summer.
Sticking ability in Spix's disk-winged bat,Thyroptera tricolor(Microchiroptera: Thyropteridae)
Authors: Riskin Daniel K , Fenton M Brock
Published: April 2011

Roosting Spix's disk-winged bats, Thyroptera tricolor, use disks on their wrists and ankles to cling to smooth leaves. In 584 trials we tested the ability of 31 T. tricolor and 121 other bats lacking disks (461 trials with 18 species from three families) to adhere to (i) medium-grade sandpaper, (ii) Lexan polycarbonate, (iii) solid sheet aluminum, and (iv) porous sheet aluminum. While T. tricolor readily adhered to smooth surfaces, the other species did not. Thyroptera tricolor did not show the same ability to adhere to rough surfaces as the other species that were tested. As was demonstrated by their performance on porous aluminum and sandpaper, the disks of T. tricolor worked by suction and sometimes by wet adhesion. In the course of adapting to adhere to smooth surfaces, T. tricolor appear to have lost some ability to roost on rough ones, although one adult T. tricolor climbed on a screen covering the inside walls of the polycarbonate cage by interlocking its thumb claws with the surface.
Changes in the diet of free-ranging black bears in years of contrasting food availability revealed through milk fatty acids
Authors: Iverson S J , McDonald, Jr. J E , Smith L K
Published: April 2011

We studied patterns of fatty acid signatures in milks and major foods of free-ranging lactating black bears (Ursus americanus) in western Massachusetts to examine the degree to which changes in milk fatty acids could be related to measured changes in food availability and scat analysis, and to assess whether fatty acids could be used to infer aspects of the diets of individuals. Milk samples (n = 45) were obtained from 17 individual bears during years of contrasting hard-mast abundance. Paired winter-den and spring-foraging samples were obtained from females in 1994 (n = 10), 1995 (n = 2), and 1996 (n = 8). In seven of these females, paired den and foraging samples were collected in both 1994 and 1996, representing two consecutive lactation periods. Milk fatty acid patterns indicated that the diet of individuals responded strongly to food availability both prior to denning and during spring foraging. During spring foraging, although females likely continued to mobilize stored fat, the greatest contribution to milk fatty acids appeared to be from dietary fat intake. Hence, qualitative changes in spring diets of individual bears could be reasonably inferred from milk fatty acid signatures. During the year of lowest hard-mast abundance, milk fatty acid patterns suggested that females relied predominantly on a diet of skunk cabbage, although this varied among individuals. This study demonstrates that milk fatty acid signatures can be used to provide insight into the nutritional ecology of bears at the level of the individual.
STUDIES ON THE DEVELOPMENT OF THE KIDNEY OF THE PACIFIC PINK SALMON, (ONCORHYNCHUS GORBUSCHA (WALBAUM)): I. THE DEVELOPMENT OF THE PRONEPHROS
Authors: Ford P. , Newstead J. D.
Published: April 2011

The literature relating to pronephros development in fishes is discussed and the course of development in the pink salmon described. The vascularization of the kidney is described and the histological differentiation of the elements of the kidney listed with special respect to the epithelia of the tubules. The appearance of the myeloid tissue is noted.
STUDIES ON THE DEVELOPMENT OF THE KIDNEY OF THE PACIFIC PINK SALMON (ONCHORYNCHUS GORBUSCHA (WALBAUM)): II. VARIATION IN GLOMERULAR COUNT OF THE KIDNEY OF THE PACIFIC PINK SALMON
Authors: Ford Peter
Published: April 2011

Counts of the glomeruli of pink salmon fry raised in fresh water were compared with those of fry raised in sea water. A significant increase in the count was observed in fry of the same fork length raised in fresh water.