bluuebunny/crossref_metadata_2025 huggingface dataset:
Exogenous and endogenous stages of Isospora brachyrhynchi sp. n. (Protozoa: Eimeriidae) from the American crow Corvus brachyrhynchos Brehm
Authors: Cawthorn Richard J. , Wobeser Gary A.
Published: March 2009

The purpose of this study was to describe, by light microscopy, exogenous and endogenous development of Isospora brachyrhynchi sp. n. from the American crow, Corvus brachyrhynchos Brehm. Crows were intubated with varying doses of sporulated oocysts of I. brachyrhynchi from a naturally infected crow and killed for necropsy at various hours postinoculation. Tissues were fixed in Bouin's fluid and processed for light microscopy. Sporulation of I. brachyrhynchi to typical isosporoid oocysts required 48–72 h at 21 ± 2 °C. Sporulated oocysts were 20.4 × 18.9 μm, with sporocysts 16.2 × 10.6 μm and sporozoites 12.9 × 2.6 μm. There was a prominent polar granule within the oocyst and a Stieda body at the blunt end of the sporocyst. Each sporozoite had a central nucleus and two refractile granules. Isospora brachyrhynchi developed below the nuclei of epithelial cells in the small intestine. First-generation merogony occurred 24 h postinoculation in villar epithelium in the distal small intestine and occasionally in the lamina propria. Second-generation merogony occurred 72–96 h postinoculation in crypt epithelium of the distal small intestine. Gametogony occurred 96 h postinoculation, primarily in villar epithelium, throughout the length of the small intestine. The prepatent period was 5 days and the patent period was long (up to 3.5 months).
The complex song of the warbling vireo
Authors: Howes-Jones Daryl
Published: March 2009

The song of the warbling vireo (Vireo gilvus) was described as a nested hierarchy consisting of four levels: song, figure patterns, figures, and figure regions. Song appeared to be organized as a set of nested undulations or cycles of tone of between 2 and 160 Hz. The dominant feature of song is its complex rhythmic structure. The complexity of song was considered to result from flexibility in the rules which governed how undulations on the various levels were combined. The first and last three figures of song showed characteristic shape. The figure repertoire was graded in form and similar among individuals. Figure patterns gradually changed in consecutive songs and during the season, forming what appeared to be a continuously changing set of themes with variations. Despite this variation, neighbouring males shared a greater number of figure patterns in their repertoires than more distant males. Redundancy, as measured in the first half of song, increased at the onset of nest building and was greatest when the male was sitting on the nest. Characters or structures in song that potentially encode species, individual, contextual, or motivational information were described.
Juvenile hormone biosynthesis during sexual maturation and after mating in the adult male migratory grasshopper, Melanoplus sanguinipes
Authors: Couche G. A. , Gillott C. , Tobe S. S. , Feyereisen R.
Published: March 2009

Juvenile hormone III is the exclusive juvenile hormone produced by the corpora allata in adult male Melanoplus sanguinipes. For the first 5 days after adult emergence, the rate of juvenile hormone biosynthesis is low, it then increases rapidly to peak on day 7. Between days 7 and 12 the rate declines to that of newly emerged males and then increases again in 14-day insects. In males allowed a single mating on day 7, the rate of juvenile hormone biosynthesis remains elevated at least to day 12.
Neonatal growth and organ allometry of Northwest Atlantic harp seals (Phoca groenlandica)
Authors: Kovacs Kit M. , Lavigne D. M.
Published: March 2009

Growth and organ allometry of neonatal harp seals (Phoca groenlandica) were monitored during the first 6 weeks of life from 1982 to 1984. At birth, pup mass was 9.9 ± 1.7 (1 SD) kg. After their 1st day of relatively slow growth, pups gained mass rapidly, increasing 2 kg/day throughout the remainder of the ~12-day nursing period. Two-thirds of this mass gain was accumulated as a layer of subcutaneous blubber. Pups lost mass at a rate of ~0.5 kg/day during the postweaning fast, utilizing energy stores from the viscera, muscles, and limited amounts of blubber. In neonates, liver mass fluctuated in conjunction with total body mass gain and loss. The liver of adult harp seals was large relative to terrestrial mammals of similar size, but relatively small compared with other pinnipeds. The heart of harp seals grew slowly in pups and did not lose mass during fasting, and in adults it was of similar size relative to other mammals. The spleen of neonates was large and grew quickly during nursing. Spleen mass was quite variable among postweaning animals. As would be expected for a large-sized, precocially born, relatively advanced mammalian neonate, pups are born with large brains that grow very slowly. Adult brain mass, in relation to body mass, was similar to that of other mammals.
Seasonal atrophy of the visceral organs in a sea cucumber
Authors: Fankboner Peter V. , Cameron J. Lane
Published: March 2009

The gut, gonad, respiratory trees, and circulatory system of the commercial sea cucumber Parastichopus californicus are annually lost as a result of atrophy of these organs and not, as originally supposed, through spontaneous, seasonal evisceration. Visceral loss is preceded by cessation of feeding–locomotory behaviour. Torpor ensues, and the visceral tissues are absorbed through a progressive process which includes phagocytosis by the sea cucumber's coelomocytes and, in some instances, the scavenging activities of endosymbionts. Regeneration of the viscera occurs within several weeks. Similar seasonal atrophy of the visceral organs has not been reported to occur in other coelomate organisms. We hypothesize that visceral atrophy in P. californicus is an expression of seasonal diapause induced by reduced food availability.
Variabilité génétique et morphologique de cinq populations de l'écrevisse européenne Austropotamobius pallipes (Lereboullet 1858) (Crustacea, Decapoda)
Authors: Attard Jean , Vianet Régis
Published: March 2009

Genetic and morphometric variability was compared for five populations of the European crayfish Austropotamobius pallipes. The good agreement of results leads to a pattern of differentiation consistent with the geographical distribution of the samples. The analysis of enzymatic polymorphism, using electrophoretic techniques on starch gel, shows a very small heterozygosity level. The genetic distance, established from allelic frequencies of 18 loci, distinguishes the populations of Haute-Saône and Ireland from a southern population group (Hérault, Gard, Haute-Corse). The examination of eight meristic and morphometric variables and the calculation of the coefficients of racial likeness also point out this highly distinctive southern group. The results of the discriminant analysis show that four of these variables could be used in a more complete study of the populations of Austropotamobius pallipes.
Multivariate differentiation of parapatric and allopatric populations of threespine stickleback in the Sangan River watershed, Queen Charlotte Islands
Authors: Reimchen T. E. , Stinson E. M. , Nelson J. S.
Published: March 2009

A discriminant analysis was made of 17 morphometric and 10 meristic characters in the freshwater form (leiurus) of threespine stickleback (Gasterosteus aculeatus) from 16 localities in the Sangan River System on the Queen Charlotte archipelago and in the presumed ancestral form (trachurus) from a nearby locality in marine waters. While multivariate means were significantly different between trachurus and leiurus, there was even greater differentiation between the leiurus populations found in lakes, ponds, and streams, divergence which was independent of geographical distance between localities. Statistical removal of meristics, removal of body length, log transformation and size standardization of all morphometries did not substantially alter the discrimination of the populations. Two of the leiurus populations that overlap in a narrow zone appear to have achieved reproductive isolation.
The duration of the period of hibernation of three species of vespertilionid bats. II. Laboratory studies
Authors: Twente John W. , Twente Janet , Brack Jr. Virgil
Published: March 2009

Variation in the duration of the period of hibernation of three species of vespertilionid bats under laboratory conditions was great. Durations of the period of hibernation of the big brown bat (Eptesicus fuscus) ranged from less than a day to 908 h (37.8 days) at 5 °C and to 1227 h (51.1 days) at 2 °C. Those for the little brown bat (Myotis lucifugus) ranged from less than a day to 1398 h (58.2 days) at 5 °C and to 1827 h (76.1 days) at 2 °C. Those for Pipistrellus subjlavus (eastern pipistrelle) ranged from less than a day to 649 h (27.0 days) at 5 °C and to 864 h (36.0 days) at 2 °C. It is proposed that the tendency toward great variation is an inherent characteristic of the bats and is not a laboratory-induced artifact. Despite great variation, a temperature dependency of the frequency of arousal was demonstrated for E. fuscus, P. subjlavus, and M. lucifugus. Slopes of regression for E. fuscus, P. subflavus, and M. lucifugus derived from semilogarithmic plots of durations of the period of hibernation versus temperature are similar to each other and to those of hibernating ground squirrels. The regulating effect of temperature upon hibernation suggests that the frequency of arousal is controlled metabolically.
Mass transfer from mother to pup and subsequent mass loss by the weaned pup in the hooded seal, Cystophora cristata
Authors: Bowen W. D. , Boness D. J. , Oftedal O. T.
Published: March 2009

We studied the components of mass transfer from mother to pup during the lactation period and weight loss by fasting pups postweaning in the hooded seal, Cystophora cristata. Measurements were taken from 33 mother–pup pairs and 69 weaned pups. Mean body weight of mothers declined from an average of 179 kg at the beginning of lactation to 150 kg for mothers nursing fat pups near the end of lactation. Over 80% of this weight loss was from the sculp (i.e., skin and blubber). Pup weight doubled during the 4 days of lactation, with about 70% of this weight gain in the form of blubber. Fasting pups lost 29% or 13 kg of their body weight between weaning and mid to late April when feeding begins. Sculp and core weight accounted for 51% and 49%, respectively, of total weight loss during this fasting period. Hooded seal mothers invest a smaller portion of their stored fat (33%) in their pup than do grey seals (85%) and northern elephant seals (58%). Our hooded seal data are consistent with the hypothesis that the abbreviation of lactation allows a reduction in overhead costs and more efficient transfer of nutrients from mother to pup.
The influence of an ecosystem-level manipulation on prey consumption by a lotic dragonfly
Authors: Wallace J. Bruce , Cuffney T. F. , Lay C. C. , Vogel D.
Published: March 2009

Pesticide application to a small headwater stream (treatment stream) resulted in massive invertebrate drift and altered community structure with respect to both biomasses and densities. The community changed from one dominated by insects to one of primarily noninsects. Insects represented 71 to 78% of total abundance and about 95% of total biomass in an adjacent reference stream during 2 years of study. During the initial treatment year, insects, mainly Chironomidae, composed less than 20% of total invertebrate biomass (<10% of abundance) in litterbags in the treatment stream. Within 2 years of the initial disturbance, invertebrate biomass in the treatment stream was again dominated by insects (90% of total) although insects represented only 36% of total abundance. Lanthus vernalis Carle (Odonata: Gomphidae) was among the insect taxa least affected by the treatment. Diets of larval Lanthus (gut analyses) reflected changes in community structure within the treatment stream, with insects representing only 13% of the prey during the initial treatment year and more than 82% during the 2nd year of recovery. In contrast, Lanthus in the reference stream consumed primarily insects (73 to 78%) in both years. These data indicate that generalist predators such as Lanthus can readily shift to alternative prey when confronted by massive changes in community structure. The results suggest that this disturbance reduced the abundance of the more profitable prey to a level where less profitable prey increased in the diet. Following the disturbance, Lanthus consumption reflected the recovery of more profitable prey in the environment. Secondary production of Lanthus approached 27% of average standing stock biomass of invertebrates in litterbags in each stream and, based on literature values for bioenergetic efficiencies, Lanthus consumed about 65% of the average standing stock biomass of invertebrates. Total consumption necessary to support production of all invertebrate predators may exceed the average standing stock prey biomass by 2.5 to 2.7 times. However, when prey turnover is considered, the potential impact of this predation on invertebrate community structure may be quite modest.
The rôle of fleshy macroalgae in the ecology of juvenile cod (Gadus morhua L.) in inshore waters off eastern Newfoundland
Authors: Keats D. W. , Steele D. H. , South G. R.
Published: March 2009

Juvenile cod (Gadus morhua) were more abundant in inshore areas with abundant fleshy macroalgae (Desmarestia spp.) than they were in green sea urchin dominated areas with only crustose coralline algae. Small juvenile cod (<125 mm) fed mainly on small zooplankton, while larger juveniles fed mainly on benthic organisms. The contribution of epiphytic animals obtained from the macroalgae was low. We suggest that the juvenile cod were associated with the algae mainly for cover, and to a lesser degree for food obtained from the algae.
Physical condition and blood physiology of wolves in relation to moose density
Authors: Messier François
Published: March 2009

This study examines the direct effects of moose density (0.23 and 0.37 animal/km2) on the nutritional status of wolves (N = 105). Low moose density depressed significantly growth of pups as assessed by their weights, total lengths, and shoulder heights. Similarly, weights of adults were negatively affected by low moose density. No consistent differences in values of 14 blood parameters were detected. Factors other than moose density clearly determined most of the variation in these measurements. In the absence of other ungulate species, wolves were nutritionally stressed when moose density decreased below 0.4 moose/km2. Under our conditions, a sharp decline in predation rate at this lower moose density seems attributable to the direct effects of malnutrition on wolf numbers.
Effects of transferring pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon embryos at different developmental stages to a low incubation temperature
Authors: Beacham Terry D. , Murray Clyde B.
Published: March 2009

We transferred embryos of pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon from 8 to 2 °C at five stages of development: 16-cell stage, blastula stage, completion of epiboly, early eye pigmentation, and late eye pigmentation. Survival rates of the embryos increased the later in development that they were transferred to 2 °C. All pink salmon blastulas transferred died, whereas 50% of chum salmon blastulas transferred survived until hatching. After epiboly was complete, survival rates of the embryos subsequently transferred to 2 °C were usually in excess of 75%. Chum salmon embryos had higher survival rates than did pink salmon embryos at all transfer stages. Significant differences were found in embryo survival rates among stocks within species and among families within stocks. Fry from early-spawning chum salmon took longer for exogenous yolk absorption ("button-up") than did those from late-spawning ones. Alevins and fry from early transfers were generally smaller than those from later ones. Different trends in embryo and alevin survival rates and alevin and fry size among stocks within species and among families within stocks were assumed to be indicative of adaptive variation to variable natural incubation environments.
Use of early successional, midsuccessional, and old-growth forests by breeding blue grouse (Dendragapus obscurus fuliginosus) on Hardwicke Island, British Columbia
Authors: Niederleitner Joe F.
Published: March 2009

Numbers of breeding blue grouse (Dendragapus obscurus fuliginosus) observed along standardized transects on Hardwicke Island, British Columbia, were significantly higher in early successional stages than in midsuccessional or old-growth forests. Numbers in old-growth and midsuccessional forests were not statistically different. Cover percentage of the herbaceous stratum may be an important component of the preferred habitat.
Marten use of clear-cuttings and residual forest stands in western Newfoundland
Authors: Snyder Joyce E. , Bissonette John A.
Published: March 2009

Marten (Martes americana) inhabit primarily old-growth coniferous and mixed wood forest habitats. Widespread forest harvest operations have prompted inquiries into whether residual patches of forest left after harvesting, or regenerating clear-cuttings, provide adequate habitat for marten. In western Newfoundland, the primary method of tree harvest has been clear-cutting of large tracts of balsam fir (Abies balsamea) and black spruce (Picea mariana). The only remaining populations of marten in the province also are found in the western part of the island, with greatest densities near Little Grand Lake. This study was designed to determine if marten used regenerating clear-cuttings and small remnant patches of residual forest left after forest operations. Habitat use by marten was investigated by livetrapping and snow tracking. Residual stands were classified into five size categories, and clear-cuttings into three categories based on height of balsam fir regeneration. From June to December 1983, marten were trapped in 43 residual stands and 35 clear-cuttings. A total of 3587 trap nights yielded 57 captures of 10 male and 8 female marten. Six (10.5%) captures were in clear-cuttings, all <15 years old; 51 (89.5%) marten were captured in residual stands. Capture rates were 0.48 captures/100 trap nights in the clear-cuttings and 2.19 captures/100 trap nights in residual stands. Capture rates were greatest in residual stands 25 to 34.9 ha in size (4.62 captures/100 trap nights). From January to March 1984, marten tracks were followed for 29 km. Although clear-cuttings represented 41 % of the study area, only 26% of marten travel was recorded there, all in clear-cuttings <15 years old. Residual stands >25 ha and undisturbed forest composed 41.3% of the study area; 41.8% of marten travel was recorded there. Smaller residual areas (<25 ha) made up only 4.2% of the total area, but 32.4% of the marten travel was recorded in these areas. These data indicate that marten seldom used clear-cuttings and used residual stands >25 ha and undisturbed forests in proportion to their occurrence, but the use of smaller residual stands <25 ha was greater than expected.
Tooth structure and buccal pores in the chaetognath Flaccisagitta hexaptera and their relation to the capture of fish larvae and copepods
Authors: Thuesen Erik V. , Bieri Robert
Published: March 2009

The teeth of Flaccisagitta hexaptera are capable of penetrating the exoskeleton of copepods. The grasping spines, anterior, and posterior teeth are all capable of piercing the epidermis of larval fish as seen in a series of scanning electron micrographs. A new type of anterior tooth structure is observed. A chemosensory function is suggested for a new set of pores found between the sets of anterior teeth. The secretory nature of the vestibular pit is clearly seen for the first time.
Bat activity over calm and turbulent water
Authors: Frenckell Beatrix von , Barclay Robert M. R.
Published: March 2009

A comparison of the activity of the little brown bat (Myotis lucifugus) over calm pools and fast-flowing riffles was performed in southwestern Alberta. Bat activity was assessed by monitoring echolocation calls using ultrasonic detectors. Activity was higher over pools than riffles. This could be due to differences in prey abundance or accessibility in the two habitats. Alternatively, water noise at turbulent sites may interfere with the bats' echolocation abilities. Sticky traps were used to assess prey abundance, and water noise was recorded for intensity–frequency analysis. Insect abundance at the height where the bats flew (< 1 m above the water) did not differ between sites, but insects close to or at water level at calm pools may be more accessible than at fast-flowing riffles. Further, water noise at riffles may decrease the efficiency with which bats detect targets.
Helminth parasites of the alimentary tract of the hakes (Merluccius, Urophycis, Phycis: Teleostei) of the Scotian Shelf
Authors: Scott J. S.
Published: March 2009

Alimentary tracts of the five common hakes of the Scotian shelf (Urophycis chuss, Urophycis tenuis, Phycis chesteri, Merluccius bilinearis, Merluccius albida) were examined for helminth parasites. A total of 29 species was found: 17 Digenea, 4 Cestoda, 6 Nematoda, 2 Acanthocephala. The greatest numbers of species were found in the closely associated U. tenuis (25) and U. chuss (19). Phycis chesteri hosted a moderate number (14) but included 3 digeneans that are typical of deep water (Anomalotrema koiae, Lethadena profunda, Paraccacladium jamiesoni) not found in the other hakes. The merlucciids were characterized by low numbers of parasite species, particularly of digeneans, but showed high prevalence of the host-specific cestode Clestobothrium crassiceps. The effects of geographic distribution, fish length, and depth of capture on parasite prevalence were examined for those parasites that were adequately represented. There was little difference in geographical distribution except in the case of C. crassiceps, in which distribution suggested a separate population of M. bilinearis on the Scotian Shelf from that of the Gulf of Maine. Fish length and depth of capture had little effect on parasite prevalence.
Avian Haemoproteidae. 25. The haemoproteids of the avian family Pycnonotidae (bulbuls)
Authors: Rahal Ellen M. , Bishop Madonna A. , Bennett Gordon F.
Published: March 2009

The haemoproteids of the avian family Pycnonotidae (the bulbuls) are reviewed. Haemoproteus otocompsae de Mello, 1935 is redescribed; Haemoproteus sanguinis Chakravarty &Kar, 1945 is resurrected and redescribed, and Haemoproteus philippinensis n.sp. is described. The distribution and prevalence of the three species are discussed.
Effects of colour bands on male competition and sexual attractiveness in zebra finches (Poephila guttata)
Authors: Ratcliffe Laurene M. , Boag Peter T.
Published: March 2009

Recent work suggests that coloured plastic leg bands may alter the sexual attractiveness and reproductive success of zebra finches (Poephila guttata). For example, males wearing red bands are more attractive to females and have enhanced reproductive success compared with males that have light green bands. Colour bands have been widely used in studies of avian behaviour and therefore could introduce bias if they regularly have a significant impact on social interactions among individuals. We carried out an experiment to assess the proximate effects of colour bands on zebra finch behaviour. Male zebra finches maintained in a large indoor aviary were given either red or light green bands and then scored for their ability to compete for a limited number of nest boxes and to attract females. The same males were randomly reassigned either red or light green bands and tested for their ability to regain boxes and attract new females. We found no correlation between band colour and a male's ability to gain either a nest or female. However, there was an association between male activity level and success. Also, those males that attracted a female in the first part of the experiment were more likely to do so in the second part of the experiment. We conclude that any immediate advantages conferred by attractive band colours may be masked under conditions of strong intermale competition for nests and mates.
Observations on body proportions and egg production in the female parasitic copepod (Salmincola salmoneus) from the gills of Atlantic salmon (Salmo salar) kelts exposed to different temperatures and photoperiods
Authors: Johnston C. E. , Dykeman D.
Published: March 2009

A total of 651 adult female Salmincola salmoneus were removed from the gills of Atlantic salmon kelts exposed to four temperature and photoperiod regimes. A comparative analysis of body proportions and egg production was undertaken on copepod samples. Mean trunk lengths were significantly different between regimes, but trunk widths were only significantly different between low temperature and 12 °C regimes. Mean egg sac lengths, widths, egg numbers, and egg diameters were significantly different between low temperature and 12 °C regimes, but not between 12 °C regimes with different photoperiods. Photoperiod may have had an effect on trunk length, but not on any other morphometric measurements. Cool water temperatures significantly reduced body size and numbers of eggs and this may account for some of the differences in body proportions observed by other investigators.
Labrocibarial sensilla in the female of the black fly Simulium damnosum s.l. (Diptera: Simuliidae)
Authors: Jefferies D.
Published: March 2009

Five types of sensilla were identified at the entrance to or within the food canal in female Simulium damnosum s.l., four on the labrum and one in the cibarium. The external morphology of these sense organs was investigated using scanning electron microscopy. Other cuticular projections present do not appear to be sensory in nature. No differences were found in the number, position, or fine structure of the mouthpart sensilla in two different cytospecies of S. damnosum, S. sanctipauli Vajime &Dunbar and S. sirbanum Vajime &Dunbar.
Interaction of trace metals Zn, Cd, and Mn, with Ca concretions in the gills of freshwater unionid mussels
Authors: Silverman Harold , McNeil James W. , Dietz Thomas H.
Published: March 2009

The interaction of Zn, Mn, and Cd with Ca concretions in the gills of unionid mussels was investigated. Raising blood levels of these ions to twice their normal values for a week does not result in significant deposition of these metals into gill concretions. The interaction of Zn with the concretions was examined in more detail both in vivo and in vitro. Isolated concretions bind Zn as rapidly as Ca. However short-term in vivo labelling studies using radiolabeled Zn and Ca verify that Zn is not added to concretions while Ca is being rapidly accumulated. These studies demonstrate that calcium concretions from the gills of unionid mussels do not indiscriminately bind divalent cations, but precisely regulate the species of divalent cation incorporated. This is further evidenced by the lack of relationship between blood or pond water cation levels and the levels of specific cations found in the concretions. Since the concretions are mobilized during the reproductive period, and serve as a source of glochidial calcium, it would be disadvantageous for these concretions to bind divalent cations for detoxification purposes.
The effect of locomotor activity on the growth of brook charr, Salvelinus fontinalis Mitchill
Authors: East Pierre , Magnan Pierre
Published: March 2009

Yearling hatchery-reared brook charr, Salvelinus fontinalis Mitchill, were trained during a 20-day period at different water velocities: 0.00, 0.85, 1.72, and 2.50 body lengths/s (bl/s). Our results indicate that growth (wet weight), food conversion efficiency, and the deposition of lipids on the digestive tract were maximized at 0.85 bl/s. The individual growth (wet weight) was also more homogeneous at this water speed. The storage of lipids in the white muscles was significantly lower in still water (0.00 bl/s) while the increase in length, the increase in the dry weight of the carcass (whole fish less internal organs), and the relative water content of the muscle showed no significant differences between the tested water velocities. Behavioural observations indicated that the frequency of agonistic behaviours between individuals was important in still water, but decreased significantly in the presence of a water current.
Social organization of sperm whales off the Galapagos Islands, February–April 1985
Authors: Whitehead Hal , Arnbom Tom
Published: March 2009

Between February and April 1985 sperm whales (Physeter macrocephalus) were tracked visually and acoustically in the waters west of the Galapagos Islands. Individuals were identified and measured photographically. Using statistical criteria the female and immature whales encountered were clustered into 13 groups with closed membership during the study period. These groups had a median estimated population of 19.5 animals each, and associated with one another at different times. The groups showed no significant immigration into or emigration from the study area during the study. Seven large males were identified. These associated with each other and the groups of females and immatures for periods lasting approximately 6 h. Individual males were found with different groups of females and immatures at different times. A simple model suggests that a male employing a "searching" strategy should encounter more oestrous females than the traditionally accepted "harem" holder when the interval between encountering groups of females is less than the duration of the females' oestrus. Neither the groups of females nor the mature males appeared to possess territories or preferred ranges within the study area. The number of large males encountered was considerably less than that expected if all large males were present on the breeding grounds, suggesting that males may not breed every year.
Denning and winter range of the porcupine
Authors: Roze Uldis
Published: March 2009

Long-term radiotelemetry was used to study patterns of den use and winter movement in porcupines (Erethizon dorsatum) in New York. Six of eight animals used dens regularly; the rest spent most of their winters in the shelter of hemlock stands (Tsuga canadensis). Animals entered dens in October–November after minimum daily temperatures had fallen below 0 °C for 6.8 days. Before this period, animals used temporary dens in response to rain or cold weather. Dens were abandoned in April when minimum daily temperatures rose above 0 °C and snow cover melted. Animals that left dens early typically sought the shelter of hemlock stands. Animals changed dens, on average, every 23 days. A single den-using adult male changed dens every 9.3 days. Den change was stimulated by disturbance. Animals showed strong year to year den fidelity. Animals shared dens 12% of the time. In all cases where sharing animals could be identified, they constituted a male–female pair that had previously shared a summer territory. Animals denned only in ready-made cavities such as rock outcrops, live hollow trees, outbuildings, and hollow logs. Heat-conserving features of such dens and of hemlock shelters are discussed. For three of four winters of the study, winter range averaged 7.4 ha, 11.4% of the nonwinter range. During the fourth winter, when snowfall was only 40% of normal, winter range did not differ significantly from nonwinter range.
Variation and heritability in egg size of the northern pintail
Authors: Duncan David C.
Published: March 2009

Sources of variation in the egg size of wild and captive northern pintails (Anas acuta) were examined in southern Alberta. Egg size, estimated by volume index (length × breadth2), was strongly correlated with weight of the fresh egg (r2 = 0.89) and weight of the 1-day-old duckling (r2 = 0.89). The body weight of pintail hens was weakly correlated with their egg size in the wild (r2 = 0.11) but was not correlated with egg size in captivity. Captive birds fed a 29% protein diet laid larger eggs than did those fed a 14% protein diet and egg size increased from first to second clutches in birds maintained on a constant diet. Egg size was not related to laying date or clutch size, and did not differ between adults and yearlings. Individual hens tended to lay eggs of a consistent size but there was no significant heritability for egg size.
Sources of phenotypic variation in the separation call of Northern Bobwhite (Colinus virginianus)
Authors: Baker James A. , Bailey Edward D.
Published: March 2009

We examined sources of phenotypic variation (genetic, cultural, or an interaction of genetic and cultural factors) among separation calls of a game farm population of Northern Bobwhite (Colinus virginianus). F1 subjects were cross-fostered at hatching and placed with adult male tutors. F2 subjects were isolated without a tutor, with a related tutor, or with an unrelated tutor. Calls of subjects were compared for differences between those subjects from different sets of parents tutored by the same adult and between groups of siblings tutored by different adults. Calls of both F1 and F2 subjects were different (P < 0.05) between familial lines at all ages examined, demonstrating that genetic factors are the major source of phenotypic variation. The implication of these results is discussed with reference to variation in calls among bobwhite populations.
Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area
Authors: Lydersen Christian , Gjertz Ian
Published: March 2009

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.
Bergmann's rule is invalid
Authors: Geist Valerius
Published: March 2009

Bergmann's rule, claiming that in homeotherms body size increases inversely with temperature so that, intraspecifically, body size increases latitudinally, is not valid, nor is the explanation of this rule. In large mammals body size at first increases with latitude, but then reverses between 53 and 65° N, so that small body sizes occur at the lowest and highest latitudes. This is predicted by the hypothesis that body size follows the duration of the annual productivity pulse, so that body size is a function of availability of nutrients and energy during periods of growth. Correlations between body size and temperature are shown to be spurious. If reduction in relative surface area is indeed an adaptation to conserve heat, then mammals should increase in size from south to north at rates two orders of magnitude greater than they do. Bergmann's rule has no basis in fact or theory.
Lemdana wernaarti n.sp. and other filarioid nematodes from Bubo virginianus and Asio otus (Strigiformes) in Ontario, Canada, with a revision of Lemdana and a key to avian filarioid genera
Authors: Bartlett Cheryl M. , Anderson Roy C.
Published: March 2009

Lemdana wernaarti n.sp. from connective tissue around the lower trachea of Bubo virginianus and Asio otus in Ontario, Canada, is distinguished by a single pair of caudal papillae, a preanal swelling, and a spicular length ratio of 4:1. The generic diagnosis of Lemdana Seurat, 1917 is emended and Singhfilaria Rasheed, 1960, Ameeria Ali, 1961, and Lemdanella Sonin, 1963, are placed in its synonymy. Eight valid species are recognized, including Lemdana pavonica (Rasheed, 1960) n.comb., Lemdana sultanae (Ali, 1961) n.comb., and Lemdana hayesi (Anderson and Prestwood, 1969) n.comb. Four additional species (Lemdana subspirallis (Diesing, 1851); Lemdana behningi Levashov, 1929; Lemdana lomonti Desportes, 1947; and Lemdana dartevellei Ezzat and Tadros, 1958) are considered species incertae sedis, and Eulimdana cypseli (Annett, Dutton, and Elliott, 1901) n.comb. is proposed for Lemdana cypseli (Annett, Dutton, and Elliot, 1901) Bartlett and Anderson, 1980. Splendidofilaria caperata Hibler, 1964 and a bossate Splendidofilaria sp. were also found in Asio otus; this is the first report of S. caperata in nonpasseriform birds. A key is given to the 16 genera containing filarioids parasitizing birds. Literature references to recent generic reviews and subsequent species descriptions are given and the following are proposed: Aproctella thahari (Gupta and Kumar, 1977) n.comb. for Carinema thahari Gupta and Kumar, 1977; Chandlerella hepatica (Schmidt and Kuntz, 1970) n.comb. for Parornithofilaria hepatica Schmidt and Kuntz, 1970; Aprocta pitangi (Vicente, Pinto, and Noronha, 1981) n.comb. for Ornithofilaria pitangi Vicente, Pinto, and Noronha, 1981; and Aprocta longispiculum (Ilyas, 1980) n.comb. for Splendidofilaria longispiculum Ilyas, 1981. The number of valid species in each genus is also indicated; only six genera have more than 10 species and five genera are monotypic.
Seasonal changes in body composition of mature female caribou and calves (Rangifer tarandus groenlandicus) on an arctic island with limited winter resources
Authors: Adamczewski J. Z. , Gates C. C. , Hudson R. J. , Price M. A.
Published: March 2009

Twelve collections of mature female caribou and calves (Rangifer tarandus groenlandicus) were conducted between June 1982 and June 1984 on Coats Island, Northwest Territories, Canada, to study seasonal changes in body composition in this winter mortality limited population. Mature females depleted reserves of dissectible fat and muscle considerably during both winters of the study, particularly the second, when nearly all dissectible fat and 32% of estimated fall muscle mass were lost. Recovery of fat and muscle was rapid during the two summers, because of good quality forage and little environmental disturbance. Lactation appeared to slow fattening in early summer 1983, but by October females achieved fatness similar to that in 1982, when a majority of females in summer and fall were nonlactating. Low rumen fill and consistently high fat and muscle levels in fall 1982 and 1983 suggested that mature females then approached "set points" in body fat and muscle content. Calves grew rapidly in summer; most of this growth was lean tissue, and their losses of body fat and muscle were severe during winter. Mature females and calves increased rumen fill substantially over winter to compensate for highly fibrous food. This made total body weight a much poorer predictor of condition than carcass weight. The liver, kidneys, and empty rumen were heaviest in summer in response to high forage quality. Poor condition of females was associated with light fetuses in May 1984.
Diet and foraging ecology of Black Guillemots in northeastern Hudson Bay
Authors: Cairns D. K.
Published: March 2009

I examined diet and foraging habitat selection by Black Guillemots (Cepphus grylle) in the eastern Canadian arctic. Birds fed on fish (Boreogadus saida, Stichaeus punctatus, Eumesogrammus praecisus) and mysid, amphipod, and decapod crustaceans. Guillemots concentrated at landfast ice edges early in the breeding season. Open-water foraging occurred principally in waters 10–30 m deep within 13 km of breeding colonies. Guillemots were aggregated on the water, but their distributions were not correlated with those of schooling prey. Guillemots feeding in open water obtained much of their food on the bottom, but some prey was likely taken during transit to and from the bottom.
Oversampling by great tits? A critique of Krebs, Kacelnik, and Taylor's (1978) "Test of optimal sampling by great tits"
Authors: Plowright C. M. S. , Plowright R. C.
Published: March 2009

The report by Krebs, Kacelnik, and Taylor (Krebs, J. R., Kacelniuk, A., and Taylor, P. 1978. Nature (London), 275: 27–31) that great tits foraging in two patches of unknown profitability behave as "optimal samplers" is reexamined. It is shown that the theoretical points of switching from "sampling" to "exploitation" were miscalculated, and that the animals in fact oversampled according to the model.
Metabolism and growth of young harp and grey seals
Authors: Worthy Graham A. J.
Published: March 2009

Metabolic rates and growth rates of juvenile harp and grey seals were monitored during the postweaning period after the onset of feeding. Growth rates varied from 0.03 to 0.32 kg d−1, depending on the level of energy intake and absolute body mass of the seal. Measurements of sculp mass (blubber with attached skin), as a percentage of total mass, indicated low rates of growth in the sculp and preferential growth in the core. When feeding started there was a 1.3- to 2.3-fold increase in standard metabolic rate, which was independent of the heat increment of feeding. Metabolic requirements of feeding seals, measured by indirect calorimetry, were between 1.2 and 7.2 W kg−1 in water and between 1.2 and 6.0 W kg−1 in air, similar to average daily metabolic rates calculated from net energy intake.
Foraging patterns of Water Pipits (Anthus spinoletta) with nestlings
Authors: Hendricks Paul
Published: March 2009

Foraging patterns of pairs of Water Pipits (Anthus spinoletta) nesting in alpine habitat in Wyoming were examined for sex-specific differences in division of space, how foraging behavior changes with nestling age, and how foraging behavior is modified to reduce the risk of nest detection by predators. Parental investment (measured by number of deliveries to nestlings, fecal sac removal, and time spent incubating and brooding) was not useful in predicting patterns of sexual niche partitioning of foraging space. There were no consistent patterns as to which sex foraged farthest from the nest. Distribution of the orientation of trip departures from nests, however, was significantly different between pair members in all cases. The mechanism(s) maintaining this pattern of spatial segregation is not known, but it may be the result of female dominance during the breeding season. Delivery rate of food to nestlings was positively correlated to nestling age. There was a concurrent positive correlation between delivery rate and percentage of foraging trips less than 50 m from the nest. Adult pipits flew significantly longer distances from nests when departing with fecal sacs. This is probably an adaptation to reduce the probability of nest detection by predators, and represents a trade-off between energy-efficient foraging and reproductive success.
Temperature preferences of three sympatric sticklebacks (Gasterosteidae)
Authors: Lachance Stephanie , Magnan Pierre , FitzGerald Gerard J.
Published: March 2009

We determined the temperature preferences of three sympatric species of sticklebacks in the laboratory to see if differences in preferences could explain variation in times of reproductive migration to and from salt marsh tide pools along the southern shore of the St. Lawrence estuary, Quebec. The preferred temperatures were 9–12 °C for Gasterosteus aculeatus (form trachurus) and 11–14 °C for G. wheatlandi, while Pungitius pungitius showed a bimodal preference of 9–10 °C and 15–16 °C. In the field, G. aculeatus and G. wheatlandi left the tide pools earlier in the season than P. pungitius. Our results suggest that temperature preference may play a role in habitat partitioning among these species, hence facilitating their coexistence at high densities in the pools.
Survivorship of adult females in a northern population of common snapping turtles, Chelydra serpentina
Authors: Galbraith David A. , Brooks Ronald J.
Published: March 2009

Survivorship of adult female snapping turtles (Chelydra serpentina) in a marked population in Algonquin Provincial Park, Ontario, was estimated using recapture records and catch-curve analysis of age structure. Known mortality was less than 1% per year, and a 13-year average of survivorship was 96.6% per year. Even the conservatively biased catch-curve estimate (92.9% per year) was among the highest yet reported for any turtle population. We compared two hypotheses to account for these high values. Although not at variance with our results, we rejected Rubner's proximal "rate of living" hypothesis because of lack of any other evidence that this process operates in reptiles. The second hypothesis was that high survivorship was the consequence of specific demographic features in a bet-hedging life-history strategy. Females would be more successful, given the high and stochastic clutch mortality and lack of predation on adults in this northern population, if they produced smaller clutches over many years than if they produced larger clutches over fewer years. This suite of characteristics may have allowed for the establishment of this northern population, or the high survivorship of adult females in this population may be an evolved response in the direction predicted by bet-hedging theory.
Ecological relationships between Common Murres, Uria aalge, and Thick-billed Murres, Uria lomvia, at the Gannet Islands, Labrador. II. Breeding success and site characteristics
Authors: Birkhead T. R. , Nettleship D. N.
Published: March 2009

At the Gannet Islands, Labrador, the proportion of Thick-billed Murres (Uria lomvia) that successfully reared a chick that left the colony was significantly lower (mean = 63%) than that of Common Murres (Uria aalge; 82%) in each of 3 years of study. The physical and social features of the breeding site were the only factors known to influence breeding success. For both murre species, breeding success increased with ledge width, and whereas most Common Murres bred on the widest ledges, relatively few Thick-billed Murres did so. The success of each species did not differ significantly on ledges of the same width. We suggest that Common and Thick-billed murres competed for breeding sites and that Common Murres obtained a disproportionate share of the "best" sites. This occurred because Common Murres outnumbered Thick-billed Murres by about 40:1 and because cliff habitat was in short supply. Whereas Thick-billed Murres bred only on cliffs, Common Murres were able to breed on cliffs and flat ground nearer sea level. Additional circumstantial evidence supports the idea that Common and Thick-billed murres at the Gannet Islands compete for breeding sites.
Changes in counts of haemocytes and in their physicochemical properties during the moult cycle in Porcellio spinicornis Say (Porcellionidae, Isopoda)
Authors: Alikhan M. A. , Naich M.
Published: March 2009

Total haemocyte counts in seventh and eighth growth-stage intermoult Porcellio spinicornis ranged, on average, from 3663.7 haemocytes/mm3 (61.70% hyalinocytes, 10.97% hemigranulocytes, and 27.31% granulocytes) in the male (mean wet weight = 0.051 g) to 4888.1 haemocytes/mm3 (58.36% hyalinocytes, 13.0% hemigranulocytes, and 28.63% granulocytes) in the female (mean wet weight = 0.054 g). Hyalinocyte count decreased by 59.75% following circumferential ecdysial split but gradually increased during anterior moult to peak at postecdysis. However, redox and surface potentials of hyalinocytes remained elevated during the moult (beginning with circumferential ecdysial split to anterior ecdysis). Granulocyte redox and surface potentials were high during the postmoult and intermoult periods, but were low during the moult. No significant changes in the hemigranulocyte and granulocyte counts were observed during the moult cycle. The significance of these findings is discussed.