bluuebunny/crossref_metadata_2025 huggingface dataset:
Forest fire's influence on yellow hedysarum habitat and its use by grizzly bears in Banff National Park, Alberta
Authors: Hamer David
Published: April 2011

Hedysarum (Hedysarum spp.) roots are a primary food of grizzly bears (Ursus arctos) in the Front Ranges of the Canadian Rocky Mountains. I studied the effects of recent forest fire on yellow hedysarum (H. sulphurescens) habitat by comparing root density, mass, fibre content, ease of digging, and use by grizzly bears in and adjacent to two prescribed burns that were conducted in Banff National Park, Alberta, in 1986 (Cascade Valley) and 1990 (Panther Valley). Digging was 12-14% easier in burned than in forested habitat. In the Cascade burn, yellow hedysarum roots were significantly more abundant and heavier than in the adjacent forest. This burn was intensively dug by grizzly bears between 1995 and 1997, but no diggings were found in the adjacent forest. In the Panther burn, no significant differences in root quality or mass were found. Bears dug few roots in the burn and did not dig in the adjacent forest. Their use of these two burns demonstrates prescribed fire's potential to create important yellow hedysarum digging habitat for grizzly bears in Banff National Park.
Effects of a mite, Limnochares americana (Hydrachnida: Limnocharidae), on the life-history traits and grooming behaviour of its damselfly host, Enallagma ebrium (Odonata: Coenagrionidae)
Authors: Léonard N J , Forbes M R , Baker R L
Published: April 2011

We examined whether experimental parasitism by a mite Limnochares americana (Lundblad) affected survivorship and maturation of adult damselflies Enallagma ebrium (Hagen). We then tested whether differences in grooming activity between control and exposed individuals (within different age or sex categories of host) mirrored reductions in fitness that resulted from experimental parasitism. We based our choice of experimental numbers of mites on our finding that adult damselflies had between 0 and 12 mites (71% had 0 mites), and mature adults had a higher prevalence and intensity of parasitism than did prereproductive damselflies in two of three field surveys. Low numbers of mites did not affect survivorship of teneral or mature males and females; however, high numbers of mites significantly depressed survivorship of teneral males and females and mature males, and were associated with a delay in maturation of females. Of teneral individuals, only females groomed more than controls when challenged with low numbers of mites; mature individuals of both sexes groomed more than controls in response to high numbers of mites but not in response to low numbers. Our results suggest that variation in grooming behaviour partially reflects variation in fitness costs, due to mite parasitism, across age and sex categories of hosts.
Sex differences in feeding-patch choice in a megaherbivore: elephants in Chobe National Park, Botswana
Authors: Stokke Sigbjørn
Published: April 2011

Differences in diet and patch choices of African elephants (Loxodonta africana) according to sex and herd structure were examined during the dry season in a dystrophic savanna-woodland ecosystem in northern Botswana. The study revealed that female elephants with dependent young fed more selectively than the very large adult males, as indicated by the large number of woody plant species utilised, in order to minimise fibre intake, at both the woody plant species level and the feeding-patch level. Adult females fed on more woody plant species per unit area in patches containing higher numbers of such plants than adult males. Family units also browsed on more woody plant species per unit area and in total than adult males. Finally, family units discriminated between patches in their surroundings and selected patches offering the highest density of palatable species, whereas males were apparently ignorant of the distribution of resources in their environment and browsed in patches containing the same amount and combination of species as surrounding areas. This suggests that body size is a paramount factor mediating dietary differences between the sexes in African elephants at both the feeding-patch and the woody plant species level. These findings are consistent with the sexual dimorphism - body size hypothesis, which states that an increase in body size leads to a relaxation of the requirement for selectivity in feeding.
Environmental and physiological determinants of successful foraging by naive southern elephant seal pups during their first trip to sea
Authors: Hindell Mark A , McConnell Bernie J , Fedak M A , Slip David J , Burton Harry R , Reijnders Peter JH , McMahon Clive R
Published: April 2011

The ability to forage successfully during their first trip to sea is fundamental to the ultimate survival of newly weaned southern elephant seals (Mirounga leonina). However, there is considerable variation in the body mass and fat content of seal pups at weaning, which results in some individuals having larger energy and oxygen stores than others, which may confer advantages on them. The diving behaviour of 21 newly weaned seals was studied using satellite relayed data loggers. Seals were captured at Macquarie Island in December 1995 and 1996, approximately 4 weeks after weaning. Two groups of seals were specifically targeted: a heavy group from the top quartile of weaning masses (n = 6) and a light group from the lower quartile (n = 15). Most of the seals made dives in excess of 100 m depth and 5 min before final departure from the island. However, for the first 60-80 d, all of the seals exhibited behaviour quite distinct from the patterns reported for older conspecifics, and made relatively shallow (100 ± 39 m; mean ± SD) and short (5.7 ± 1.23 min) dives. During this time the seals spent 74.3 ± 12.6% of each day diving, and the depth of the dives did not follow any diurnal pattern. The diving behaviour of all seals changed abruptly when they started on their return to land. During this time their behaviour was more like that of adults: they made deeper (159 ± 9 m) and longer dives (9.01 ± 1.69 min) than previously, and the dives showed a strong diurnal pattern in depth. There is no obvious explanation for this change in behaviour, although its abrupt nature suggests that it is unlikely to have been due to physiological changes in the seals. The size of the seals at weaning was an important influence on diving behaviour. Heavy weaners made significantly deeper (130 ± 40 m) and longer dives (7.36 ± 0.55 min) than light weaners (88 ± 32 m and 5.04 ± 0.64 min, respectively). This indicates that smaller seals are constrained to some extent by their physiological capabilities, which perhaps requires some individuals to adopt different foraging strategies.
Behaviour of ringed seals tagged with satellite transmitters in the North Water polynya during fast-ice formation
Authors: Teilmann Jonas , Born Erik W , Acquarone Mario
Published: April 2011

To gain insight into the use by ringed seals (Phoca hispida) of the North Water polynya (northern Baffin Bay), we monitored the movements and diving behaviour of eight ringed seals caught in the fjords of the Thule (Avernarsuaq) area in Northwest Greenland. The animals were caught in August-September 1996 and equipped with satellite transmitters. Contact with the seals was maintained for up to 146 days. Two of the seals left the study area soon after being equipped, one moved north to the Kane Basin and one moved to southeastern Baffin Island. The departure of the other six seals from the fjords was apparently related to the formation of landfast ice. After formation of the polynya, all positions were close to the edge of the fast ice in the Thule area. Of the six seals that stayed in the North Water, three females preferred areas with shallow water (<100 m), while three males with larger body mass remained mainly in areas with deeper waters (>100 m). The "shallow-water" seals dove significantly more frequently to depths of less than 50 m than the "deep-water" seals, whereas the deep-water seals made significantly more dives that were deeper than 50 m. However, all seals occasionally dove to depths of more than 250 m.
Comparative body composition strategies of breeding and nonbreeding female caribou
Authors: Chan-McLeod Ann C. Allaye , White Robert G , Russell Don E
Published: April 2011

We evaluated the effects of season and reproductive status on body fat and body protein masses of free-ranging female barren-ground caribou (Rangifer tarandus granti). Body fat mass fluctuated markedly during the year (by a factor of at least 2) in both reproductive classes, but whereas maximum fatness occurred in autumn (September-November) in nonbreeding females, it did not occur until late winter (March-April) in breeding females. Seasonal changes in dry body protein mass were relatively modest, with annual maxima averaging only 31-43% higher than annual minima. Moreover, seasonal differences between the reproductive classes were not significant except in November-December. Absolute fat deposition by both breeding and nonbreeding females was highest in summer, though fat deposition increased relative to protein deposition in autumn. Between June and September, the primary deposition of body protein in breeding females contrasted with the primary deposition of body fat in nonbreeding females. As a result, breeding females were highly compromised in their fat deposition but not in their protein deposition, which approximated levels in nonlactating females. Differences in body composition between breeding and nonbreeding females were highest in autumn and lowest in early spring because of divergence in summer and convergence in winter.
Seasonal variation in coyote feeding behaviour and mortality of white-tailed deer and mule deer
Authors: Lingle Susan
Published: April 2011

Young ungulates are considered especially susceptible to predation in the initial weeks following birth. However, the timing of mortality can vary depending on the availability of alternative prey and the type of predator, and could vary depending on antipredator defenses used by prey. I used coyote (Canis latrans) scats, observations of coyote hunting behaviour, and mortality data for deer to examine seasonal variation in coyote feeding behaviour and mortality of sympatric white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) fawns. Coyotes captured the vast majority of deer they consumed, forming groups that hunted deer from June through March. Coyotes were observed hunting deer most often in winter when ground squirrels were not available, and an inverse correlation between the amount of deer and ground squirrel in coyote scat reflected this relationship (rs = 0.77, P = 0.004). Fawns of both species had poor survival rates in 1994 (1 of 10 tagged whitetails survived to 1 year, none of 22 mule deer survived), improved survival rates in 1995 (33% of 15 whitetails, 25% of 24 mule deer), and most mortality appeared to be due to coyote predation. The season in which fawns of each species were most vulnerable differed. Tagged whitetail fawns had similar mortality rates in early summer, when they were less than 8 weeks old, as they did in winter, when they were 5-9 months old (35 and 37%, respectively, in 1995). In contrast, mule deer fawns had low mortality rates in early summer (4% in 1994, 17% in 1995), but high mortality rates in winter (100% in 1994, 53% in 1995). Changes in fawn:doe ratios and the examination of carcasses similarly indicated that coyotes captured more whitetails in summer and more mule deer in winter. The seasonal variation in mortality rates of the two species cannot be explained by physical prey characteristics, their relative abundance, or extrinsic factors, and may be due instead to species differences in antipredator behaviour.
Status of a broadly distributed endangered species: results and implications of the second International Piping Plover Census
Authors: Plissner Jonathan H , Haig Susan M
Published: April 2011

Methods for monitoring progress toward recovery goals are highly variable and may be problematic for endangered species that are mobile and widely distributed. Recovery objectives for Piping Plovers (Charadrius melodus) include attainment of minimum population sizes within specified recovery units, as determined by two U.S. and two Canadian recovery teams. To assess progress toward these goals, complete surveys of the species' winter and breeding ranges in Canada, the United States, Mexico, the Bahamas, and the Greater Antilles are conducted every 5 years. In 1996, 1200 biologists and volunteers participated in the second International Piping Plover Census, tallying 2515 wintering birds and 5913 adults (2668 breeding pairs) during the breeding census. Winter numbers were 27% lower than those of the first international census conducted in 1991, with substantially fewer wintering birds along the Gulf of Mexico and an overall increase in numbers along the Atlantic Coast. Large numbers of wintering plovers remain undetected. In 1996, the total number of breeding adults was 7.7% higher than in 1991. Regionally, breeding numbers were 31% higher along the Atlantic Coast and 20% higher in the small Great Lakes population, but declined by 5% in the U.S. Great Plains and the Canadian Prairie. Target recovery numbers were met only for Saskatchewan but were approached in Alberta and New England. The results suggest that Piping Plover distribution and habitat use in the U.S. Great Plains/Canadian Prairie region may shift dramatically with water conditions.
Food stress, nestling growth, and fluctuating asymmetry
Authors: Hovorka Mark D , Robertson Raleigh J
Published: April 2011

It has been suggested that fluctuating asymmetry (FA) is an indicator of perturbed development. Our study tests the validity of a fundamental assumption of asymmetry theory: that environmental stress imposed during development increases FA. We deprived tree swallow (Tachycineta bicolor) nestlings of food for 3 h every morning from days 3 to 15 of brood age. We obtained 2 repeated measurements of the right and left ninth primaries, outer rectrices, and tarsi, and one measure of body mass on days 8, 12, and 16. Food-deprived nestlings had significantly smaller character sizes (all characters for all days), significantly lower wing and tail feather growth rates, and significantly higher tarsal and mass growth rates than control nestlings. However, food deprivation did not cause experimental nestlings to exhibit significantly greater FA than control nestlings. Nestling mass and FA were not associated within treatments or across broods, and brood size had no significant effect upon the character size, growth rate, or FA level in nestlings. Measurement errors were small and size scaling, antisymmetry, and directional asymmetry did not confound FA estimates. Our results suggest that the ninth primaries and outer rectrices of tree swallows are unreliable indicators of FA-stress relations because of strong stabilizing selection for symmetry in this aerially insectivorous species.
Hormonal manipulations of growth rate and its influence on predator avoidance - foraging trade-offs
Authors: Abrahams M V , Pratt T C
Published: April 2011

Theoretical investigations into the impact that predators exert on prey species suggest that two parameters, growth rate and mortality rate, should be the most influential in determining when animals should risk exposure to a predator in order to achieve higher feeding rates. While these two parameters have usually been assumed to be environmentally determined, we used thyroid hormone (3,3prime,5-triiodo-L-thyronine (T3)) to manipulate growth rates and examine the behavioural consequences associated with these manipulations. In two experiments, we examined how the growth rate of fathead minnows (Pimephales promelas) is affected by treatment with T3, and used the results from this experiment to make a priori predictions about their relative willingness to risk exposure to a predator in order to receive increased feeding rates. The first experiment demonstrated that T3 significantly reduced the growth rates of fathead minnows compared with an unmanipulated control. When groups were compared in their relative willingness to risk exposure to a predator, manipulated growth rates in the first experiment were an accurate predictor of behaviour; groups with relatively high growth rates were more willing to risk exposure to a predator. These results are consistent with the theoretical expectation that growth rates should be an important factor determining decisions that involve trade-offs.
Comparative diving behaviour and segregation of the marine habitat by breeding Royal Penguins,Eudyptes schlegeli, and eastern Rockhopper Penguins,Eudyptes chrysocome filholi, at Macquarie Island
Authors: Hull Cindy L
Published: April 2011

Comparative use of the water column by Royal Penguins, Eudyptes schlegeli, and eastern Rockhopper Penguins, Eudyptes chrysocome filholi, was examined by comparing their diving behaviour at Macquarie Island during the 1993-1994, 1994-1995, and 1995-1996 breeding seasons. Fifty-eight deployments of time-depth recorders measured depth and duration of dives, time spent submerged, bottom time, occurrence of wiggles, and descent and ascent rates. Both species dived predominantly during daylight hours (4:00-21:00 local time), with shallower dives around midday. Royal and Rockhopper penguins spent 38.9 ± 8.9 and 36.6 ± 9.3% of a 24-h period under water, respectively, but Rockhopper Penguins performed more dives (14.8 ± 9.4/h) of shorter duration (1.2 ± 0.7 min) than did Royal Penguins (11.1 ± 6.9 dives/h; 1.7 ± 0.6 min). Although both could dive to over 100 m, they rarely did so, with Royal and Rockhopper penguins making 79 ± 0.13 and 91 ± 0.08% of their dives to depths of less than 60 m, respectively. Although the difference was not significant, Royal Penguins dived in deeper water (32.9 ± 25.6 m) than did Rockhopper Penguins (27.3 ± 20.3 m). However, Royal Penguins performed wiggles (assumed foraging activity) in water significantly deeper (47.7 ± 24.3 m) than did Rockhopper Penguins (41.3 ± 19.0 m). Royal Penguins also performed more dives with wiggles than Rockhopper Penguins, suggesting differences in foraging technique. The amount of time both spent at the bottom of dives increased across the breeding season from incubation to chick rearing. As dive durations and ascent and descent rates did not change during this time, dive angles must have changed. There were no interannual differences in the diving behaviour of Royal Penguins, but Rockhopper Penguins exhibited differences in dive depths and durations and in the amount of bottom time. Royal Penguins, unlike Rockhopper Penguins, performed fewer dives on the first day of foraging trips, indicating more travelling and less foraging, which reflects differences in foraging zones between the two. The estimated foraging efficiency of Rockhopper Penguins was lower than that of Royal Penguins, probably making them more vulnerable to changes in prey availability and abundance. The two species exhibited some differences in diving behaviour but overlapped substantially in their use of the water column. Therefore, for minimising competition for resources, segregation in this aspect of their habitat is far less important than differences in diet and foraging zone.
An examination of the manipulation hypothesis to explain prevalence of Parelaphostrongylus tenuis in gastropod intermediate host populations
Authors: McCoy Karen D , Nudds Thomas D
Published: April 2011

There are many examples of parasites that manipulate intermediate host behaviour facilitating transmission to the definitive host. We examined this hypothesis as a possible explanation for the observed prevalence of Parelaphostrongylus tenuis, a nematode parasite of white-tailed deer (Odocoileus virginianus) in eastern North America. The prevalence of this parasite in deer populations is typically high compared with its prevalence in its gastropod intermediate hosts. It is unclear how high levels of prevalence are maintained, given that the transmission of this parasite to deer is considered to occur by the accidental ingestion of infected gastropods. We tested the manipulation hypothesis by comparing the vertical climbing behaviour of infected and uninfected individuals of a known intermediate host species, Mesodon sayanus. Snails climbed higher at dawn than during the rest of the day and adults climbed higher than juveniles, but no differences were found between infected and uninfected snails. These results do not explain the observed levels of prevalence, but they improve our understanding of the transmission of P. tenuis, specifically when examining the relative importance of different gastropod intermediate hosts. We review competing hypotheses that might account for the apparent discrepancy in levels of prevalence.
Helminth communities of yellow perch (Perca flavescens (Mitchill)): determinants of pattern
Authors: Carney J P , Dick T A
Published: April 2011

Twenty-eight parasite species were recorded from 504 yellow perch (Perca flavescens) collected from Dauphin Lake and Beaufort Lake, Manitoba, and Lake Winnebago, Green Bay, and Lake Michigan, Wisconsin. Four parasite species, Diplostomum spp., Urocleidus adspectus, Proteocephalus pearsei, and Raphidascaris acus, occurred in perch from all localities. Infracommunities and component communities were low in richness. The Dauphin Lake and Beaufort Lake samples had the richest parasite communities, while those in the Green Bay and Lake Michigan samples were the least rich. The effect of host size and age on parasite community structure was equivocal. A positive association between P. pearsei and Bothriocephalus cuspidatus and more multispecies infracommunities than expected provide evidence of nonrandom associations in the Manitoba samples, while the Wisconsin infracommunities were random associations. Significant infracommunity nestedness in all samples indicated nonrandom community organization and structure. Parasite faunas were richer in samples with complex invertebrate communities than in samples with complex fish communities. The trophic status of the aquatic system indirectly affected the parasite communities by limiting the variety of potential intermediate hosts. Predictions regarding relationships between parasite community structure and lake trophic status were not supported. We show that predictable patterns at the fine-scale local level of the parasite infracommunity and component communities of perch are best explained by a rich invertebrate community upon which the host feeds.
The use of visual cues for spatial orientation in the sleepy lizard (Tiliqua rugosa)
Authors: Zuri I , Bull C M
Published: April 2011

The sleepy lizard (Tiliqua rugosa) is a large, long-lived terrestrial Australian skink. In the present study we investigated the ability of sleepy lizards to use different visual cues for spatial orientation. The lizards were trained to locate shelters in certain places and then trained to certain signals associated with their shelters. In the absence of surrounding visual cues the lizards preferred familiar sites that were previously associated with their shelters. However, when presented with signals that had been associated with their shelters, they chose the vicinity of these familiar signals, even after their displacement to new sites. The lizards discriminated between black and white signals and between triangular and circular signals but not between red and green signals. Previous studies had shown that sleepy lizards exhibit home-range fidelity, raising the question of which environmental cues are important for them for spatial orientation within their home ranges. We suggest that the ability of sleepy lizards to discriminate between visual signals of different shapes and degrees of brightness enables them to "memorize" certain fixed landmarks in their large home ranges and to orient accordingly.
Monitoring vertebrate populations using observational data
Authors: Hochachka Wesley M , Martin Kathy , Doyle Frank , Krebs Charles J
Published: April 2011

Methods for monitoring temporal changes in population size vary from intensive and potentially expensive to less intensive and more easily implemented techniques. In this paper we evaluate the utility of a monitoring technique that can be used to follow many vertebrate species simultaneously at low cost and requires little training of personnel. Observers record the number of individuals seen per hour in the field and these rates of encounter are used as an index of population size. We examine whether encounter rates reflect population size by comparing them with independent censuses of three species over a 7-year period in the boreal forest near Kluane Lake in the southern Yukon Territory. Encounter rates were generally an accurate reflection of variation in population size. In our study system, inter-observer variability did not influence our ability to detect fluctuations in population size: the underlying fluctuations were detected whether data from all or only a group of "high-quality" observers were used. In our study, the benefit of using all available data outweighed the cost of variation among observers because sample sizes were large (averaging over 1200 data points from 33 observers per year). Variation in the length of observation periods did not affect the chance of detecting animals in our study. Encounter rates provide a reasonable index of variation in population size, although caution should be used with species that are uncommon or difficult to detect.
A histological examination of the holding sacs and glandular scent organs of some bat species (Emballonuridae, Hipposideridae, Phyllostomidae, Vespertilionidae, and Molossidae)
Authors: Scully William MR , Fenton M B , Saleuddin A SM
Published: April 2011

Using histological techniques at the light-microscope level, we examined and compared structure and sexual dimorphism of the wing sacs and integumentary glandular scent organs of 11 species of microchiropteran bats. The antebrachial wing sacs of the Neotropical emballonurids Peropteryx macrotis, Saccopteryx bilineata, and Saccopteryx leptura differed in size and location but lacked sudoriferous and sebaceous glands, confirming that they were holding sacs rather than glandular scent organs. Glandular scent organs from 11 species consisted of sebaceous and (or) sudoriferous glands in emballonurids (P. macrotis, S. bilineata, S. leptura, Taphozous melanopogon, Taphozous nudiventris), hipposiderids (Hipposiderous fulvus, Hipposiderous ater), the phyllostomid Sturnira lilium, the vespertilionid Rhogeessa anaeus, and molossids (Molossus ater and Molossus sinaloe). Glandular scent organs were located on the face (H. fulvus, H. ater), gular region (S. bilineata, P. macrotis, T. melanopogon, M. ater, M. sinaloe), chest (T. nudiventris), shoulder (S. lilium), or ears (R. anaeus). Glandular scent organs showed greater similarities within than between families, and typically were rudimentary or lacking in females. Scanning electron microscope examination revealed that the hairs associated with glandular areas of male T. melanopogon were larger and had a different cuticular-scale pattern than body hairs. These were osmetrichia, hairs specialized for holding and dispersing glandular products. In S. lilium, hairs associated with the shoulder scent-gland area were larger than body hairs but similar in cuticular-scale pattern.
Stable-isotope and electron-microscopic evidence that cyamids (Crustacea: Amphipoda) feed on whale skin
Authors: Schell Donald M , Rowntree Victoria J , Pfeiffer Carl J
Published: April 2011

Cyamids (Crustacea: Amphipoda) are found only on whales. Observational evidence and the morphology of the mouthparts have indicated that whale skin is the primary food for these organisms. It has also been suggested, however, that the cyamids may be feeding on epidermal diatoms and meiofauna associated with the skin or using the whales as transport to regions of high zooplankton densities, where small pelagic organisms are captured while the whales feed. Here we report electron-microscopic and isotopic evidence that whale skin was ingested and assimilated by cyamids. Stable carbon and nitrogen isotope ratios of cyamids and whale skin from six species of whales were compared with those of zooplankton from the regions through which the whales migrate, to infer the most likely food sources. In all cases, cyamid isotope ratios closely matched those of the whale skin and not those of the zooplankton, again indicating that whale skin was the predominant food source. Unlike most other carnivorous organisms, cyamids do not show a trophic enrichment of δ15N, a trait also found in other species of Amphipoda.
A helminth community in breeding Yellow-legged Gulls (Larus cachinnans): pattern of association and its effect on host fitness
Authors: Bosch Marc , Torres Jordi , Figuerola Jordi
Published: April 2011

We studied the community of helminths parasitizing adult Yellow-legged Gulls (Larus cachinnans) sampled during three consecutive breeding seasons in a western Mediterranean colony. The helminth community was depauperate, probably because of the high trophic dependence of the gullery on waste food from refuse dumps. The prevalences of two helminth species varied both among years and between the sexes of gulls, while the intensity of parasitism did not vary significantly for any helminth species. No clear pattern of association between helminth species was detected, showing an unstructured helminth community in which the occurrence of any species was not restricted or favoured by the occurrence of any other species. The lack of associations might be influenced by the fact that only one core species occurred in the helminth community. Negative relationships were found between occurrence of certain helminths and body condition of hosts. Gulls infected by Tetrabothrius (Tetrabothrius) erostris were leaner than uninfected gulls; interestingly this negative relationship varied with the presence/absence of Cosmocephalus obvelatus. Moreover, body condition of gulls infected by C. obvelatus varied according to the year of sampling, while that of uninfected individuals showed no variability. High intensities of the parasites Eucoleus contortus and Brachylaima sp. were associated with poorer body condition of the host. In the case of E. contortus, this negative relationship with gulls' body condition was more pronounced in male than in female gulls. The results show that helminth pathogenicity can be affected by helminth community structure, environmental factors, and traits of the host.
Elevated numbers of flying insects and insectivorous birds in riparian buffer strips
Authors: Whitaker Darroch M , Carroll Allan L , Montevecchi William A
Published: April 2011

We compared the abundances of flying insects along undisturbed lakeshores and riparian buffer strips in balsam fir (Abies balsamea) forests in western Newfoundland. Insects were collected in pan traps placed on the forest floor and tanglefoot (sticky) traps suspended within the live canopy. Significantly greater numbers of insects were captured in riparian buffer strips than in undisturbed shorelines for four of five size classes in the canopy and two of five size classes in the understory. Collections were dominated by adult Diptera and Hymenoptera. Mean capture rates along buffer strips were 120-200% of the mean capture rates along undisturbed shorelines. This increase was greatest for large-bodied insects. A likely explanation for our observations is that buffer strips act as windbreaks, collecting airborne insects blown in from adjacent clearcuts and lakes. This phenomenon has been widely documented in agricultural landscapes. Understory wind speed was generally greater along buffer strips than controls, which is a reflection of increased exposure caused by clear-cutting. A concurrent parallel study conducted at the same sites investigated the effects of riparian buffering on breeding bird assemblages. Ubiquitous insectivorous birds, including the yellow-rumped warbler (Dendroica coronata) and blackpoll warbler (Dendroica striata), were more abundant along buffer strips than undisturbed shorelines, possibly in response to increased prey availability. Increased food availability may in part explain the high numbers of insectivorous birds typically observed in riparian buffer strips in boreal forests.
Reproductive response of Great Tits, Parus major, in a naturally base-poor forest habitat to calcium supplementation
Authors: Mänd Raivo , Tilgar Vallo , Leivits Agu
Published: April 2011

Recent studies have revealed that some forest passerines have difficulty obtaining sufficient calcium (Ca) for their eggshells in heavily acidified areas. However, the effect of Ca limitation on breeding success in non-acidified but naturally base-poor breeding habitats is not yet clear. The issue itself is important, insofar as the cost of egg formation in a certain habitat depends on the availability not only of energy and proteins but also of shell-formation material. We studied the effect of experimental supplementation with extra Ca on the reproductive output of Great Tits, Parus major, breeding in base-poor pine forests in Estonia. Pairs provided with Ca started egg laying earlier than control pairs, and clutch volume was larger in Ca-supplemented nests. There was also a positive effect of Ca supplementation on fledglings' tarsus length and body mass in the year when breeding conditions were the most unfavorable. However, no significant differences were found between the experimental and control groups in hatching success or number of fledglings. We suggest that Ca deficiency is a less limiting factor in naturally base-poor forests than in highly acidified areas, and that birds are able to adjust their breeding efforts to conditions of Ca deficiency. Great Tits, for instance, may respond to Ca shortage by postponing egg laying until their body condition and rate of food intake reach a critical threshold for producing viable eggs and young.
Parr-smolt transformation in Atlantic salmon: thyroid hormone deiodination in liver and brain and endocrine correlates of change in rheotactic behavior
Authors: Specker Jennifer L , Eales J Geoffrey , Tagawa Masatomo , Tyler, III William A
Published: April 2011

We tested the hypothesis that metabolism of thyroid hormones by the brain of Atlantic salmon (Salmo salar) changes when rheotactic behavior reverses during parr-smolt transformation (PST). We measured brain and liver thyroxine (T4) and 3,5,3'-triiodo-L-thyronine (T3) outer-ring deiodination (ORD) and inner-ring deiodination (IRD) activities and plasma T4and T3levels in Atlantic salmon held under natural photoperiod in fresh water at 10°C in the spring of 1993 and 1994. We also measured changes in T4, T3, and cortisol levels during the change in rheotactic behavior. Condition factor decreased while salinity tolerance improved from mid-March to late April. The turbidity-induced transition from upstream to downstream swimming occurred in mid to late April. The main changes in brain deiodination were reduced T3IRD (1993 study) and elevated T4ORD (1994 study). In both years, a high ratio of T4ORD/T3IRD activities in the brain indicated an increased potential for T3production in the brain during advanced PST. Liver deiodination profiles differed between years, but during advanced PST the low T4ORD activity and low T4ORD/T3IRD activity ratio suggested a low potential for hepatic, and hence systemic, T3production. However, plasma T4was increased in downstream swimmers at 1 d (1993) and 4 h (1994) after the turbidity increase. Since at this time brain deiodination pathways were poised towards T3production, the surge in plasma T4would likely increase local T3formation in brain. We conclude that during PST there is no major change in hepatic deiodination and hence probably no major change in systemic T3availability. But deiodination properties in brain during late PST indicate the potential for local T3formation. This may be significant when plasma T4increases at the time of downstream migration.
Adapted Interactive Writing Instruction With Kindergarten Children Who Are Deaf or Hard of Hearing
Authors: Williams Cheri
Published: April 2011

The study describes an adapted form of interactive writing (McCarrier, Pinnell, & Fountas, 2000) and examines its effectiveness as an approach to beginning writing instruction for young children who are deaf or hard of hearing. Systematic videotape analysis was used to document the content of 45 adapted interactive writing lessons across an academic year. Findings of the study suggest that interactive writing has the potential to support early writing development in young deaf and hard of hearing children, if supplemented by techniques that make the phonology of English visible.
Faculty Needs, Doctoral Preparation, and the Future of Teacher Preparation Programs in the Education of Deaf and Hard of Hearing Students
Authors: Benedict Kendra M. , Johnson Harold , Antia Shirin D.
Published: April 2011

The purposes of the study were to obtain and analyze data on the need for, and desired characteristics of, faculty in deaf education at American institutions of higher education (IHEs), and to assess the present and projected status of doctoral-level teacher preparation programs in deaf education at American IHEs. Program directors and coordinators provided information on current and projected faculty openings, the number of active doctoral students, faculty research interests, program strengths, and needs in the field. Results indicated a pending shortage due to faculty retirements and a paucity of doctoral-level graduates. Most faculty listed literacy and language as a primary research interest as well as a program strength. The ability to generate new knowledge through research was found to be less desirable for future faculty than teaching ability. Suggestions for improving doctoral preparation and moving the field to evidence-based practices are provided.
How Is It Then with the Whale? : Using Scientific Data to Explore Textual Embodiment
Authors: Calkins Jennifer
Published: April 2011

According to Glen Love in Practical Ecocriticism , ecocriticism's primary challenge is the engagement of the nonhuman world in critical analysis. To engage one aspect of the nonhuman world, the animal "other" and its role in literature, ecocritics must consult scientific studies of the sensory, cognitive, and behavioral worlds of animals. Current studies are upending previously held scientific and cultural assumptions about many animals, and the idea of "animal" itself. This essay presents examples of such research in the study of the avian brain and visual system, then goes on to examine the iconic embodiment of the sperm whale in Melville's Moby-Dick .
Lost Dogs, Last Birds, and Listed Species: Cultures of Extinction
Authors: Heise Ursula K.
Published: April 2011

Humankind is currently confronted with what some biologists call the sixth mass extinction of species in the history of life on Earth, and the first one triggered by humans. This essay places the narrative that usually accompanies scientific accounts of biodiversity loss in relation to the long tradition of environmentalist stories about the decline of nature. It demonstrates how elegiac and tragic story templates turn accounts of the decline of a particular species into tools for a broader critique of modernization processes, and explores an alternative, comedic narrative template that approaches extinction in the context of evolution, contingency, and experiment.
Transcendental Idealism and the Problem of the External World
Authors: Fincham Richard Mark
Published: April 2011

Kantian transcendental idealism has often been praised for resolving dialectical conflicts and attacked for "representationalism." This paper defends Kant against "representationalism" by suggesting that pre-critical attempts to prove the reality of external objects lead to a dialectical conflict, which, while not explicitly outlined in the Kritik , the Kritik nonetheless resolves. That the Kritik resolves dialectical conflicts in addition to those which it explicitly describes is suggested by Reinhold's Briefe , which Kant himself endorsed. For Reinhold, attempts to justify religious belief produce a dialectical conflict between metaphysical appeals to speculative reason and hyperphysical appeals to "blind faith," which Kant resolves by reconciling both opposed claims. The dialectical conflict concerning the external world takes a similar form: The thesis describes Descartes's claim to know that representations correspond to real things by rational inference; the antithesis describes Hume's claim that conviction in the reality of the external world is merely the pre-rational "belief" that representations immediately correspond with external objects. Transcendental idealism resolves this conflict by demonstrating that conviction in the identity of representation and object is rationally justifiable. Therefore, far from reducing empirical reality to a mere veil of ideas, Kant actually rationally demonstrates the reality of the external world.
Intelligible Species in the Mature Thought of Henry of Ghent
Authors: Rombeiro Michael E.
Published: April 2011

Henry of Ghent (1217?–93), a prominent theologian at the University of Paris during the last quarter of the thirteenth century, was a central figure on the issue of cognition and one of the first to reject intelligible species as mediating representations in the intellect's act of understanding. Scholars disagree, however, on some key elements of his alternative account. This paper clarifies Henry's doctrine on intelligible species, as well as other forms of mental representation, like the concept or mental word. In breaking with the standard Aristotelian account of Thomas Aquinas, Henry offered a unique and innovative view on species, which had a significant influence on subsequent medieval thinkers.
"Bad Men and Angels from Hell": The Discourse of Universalism in Early National Philadelphia
Authors: Lindman Janet Moore
Published: April 2011

In the winter of 1780, a disagreement over Universalism broke out in the Philadelphia Baptist Church. Led by their minister Elhanan Winchester, many church members adopted Universalism, while others resisted giving up their Calvinist belief in particular salvation. Opponents condemned this new tenet as perilous to orthodox Christianity; the salvation of all humans meant that even "bad men and angels from hell" would attain saving grace. The Anti-Universalists used discourse that played on fears of Catholicism, immorality and atheism to confront this threat. Winchester and the proponents of Universalism utilized democratic language to expand Protestant identity by advocating one religion for all. The inclusiveness of Universalism appealed to some of the Revolutionary generation who wished for an efficacious faith that was both rational and spiritual. Universalists endorsed a religion that fit the social and political context of the new nation. Their compassionate theology would benefit Americans by enhancing personal piety, promoting spiritual community, and uniting all Protestants. The argument over Universalism in Philadelphia started as a local event and became part of a national discussion about the nature of deliverance. The controversy spawned in Pennsylvania occurred in a locality familiar with religious interaction but intensified through the burgeoning print and denominational networks of the late eighteenth century. Instigated by an active laity, dissemination of this debate relied upon connections among denominational leaders. Though the rift over Universalism in the Philadelphia Baptist Church transpired at the micro level, it was linked to an ongoing religious dialogue among Protestants in the Atlantic world.
Homer's Odyssey : Penelope and The Case for Early Recognition
Authors: Vlahos John B.
Published: April 2011

In 1950 Philip Whaley Harsh suggested tht Penelope in book 19 of the Odyssey first suspected that the stranger in the palace was her husband. The standard interpretaion of Penelope's recognition of Odysseus would have us believe that she does not recognize him until book 23. The time of Penelope's recognition, however, can only be determined in how the Odyssey is read. Is the Odyssey a straightforward story or does it have subtlety and sophistication that requires reading between the lines to determine the actors' motives for their actions? Why does Penelope suddenly desire to show herself before her hated suitors in book 18? Why does Penelope fail to ask the stranger what he knows about her husband's whereabouts in book 19 when that was the purpose of the interview? Why does she ask the stranger to interpret a dream that she supposedly had when the dream is self-interpreting? Why does she decide to hold a contest with the bow with her as the marriage prize when she has been told that her husband is near? These are some of the questions the present paper attempts to answer while suggesting that Penelope suspects that her husband may have returned in disguise as early as book 17 and confirms his identity in book 19.
Penelope's "Early Recognition" of Odysseus from a Neoanalytic and Oral Perspective
Authors: Reece Steve
Published: April 2011

Many details in the narrative and dialogue of the Odyssey depict a Penelope who is oblivious to, or at least unsure of, Odysseus's identity until he has successfully passed her test of the marriage bed in book 23. But several other details depict a Penelope who seems to have at least a premonition, if not actual knowledge, of Odysseus's identity much earlier in the tale. This tension in our inherited text of the Odyssey has been variously explained for some two millennia. I favor an explanation based on an approach that I call "neoanalysis with an oral twist." In short, it assumes that lying behind the particular instantiation of the return tale that we know as Homer's Odyssey there existed various other versions of the tale in which the plot developed somewhat differently: in which, for example, Penelope recognized Odysseus much earlier in the narrative and colluded with him in the destruction of the suitors. These other versions lingered in the mind of the poet, as well as of his audience, during the composition and performance of the Odyssey and have therefore left vestiges in our surviving text.
The Case for the Defense
Authors: Richardson Scott
Published: April 2011

John Vlahos's bold and confident assertion that Penelope recognizes Odysseus well before book 23 will be controversial among readers who follow the party line established by the literal-minded Eustathius. Once we accept the likelihood, however, provided by evidence quite clear once it is pointed out, that the narrator is not as blatant and upfront as we generally assume, Vlahos's case becomes quite plausible. In fact, the traditional view that Penelope is clueless until she performs the bed-trick starts to sound rather naïve and does not do justice to Homer's talent for indirection and subtlety. The argument for early recognition makes better sense of the final third of the epic than the usual assumption of her ignorance.
The Conservative Avant-Garde
Authors: Schechner Richard
Published: April 2011

The avant-garde, regarded as “radical” or “new,” is conservative. To understand what and why this is, we must not only understand what “conservative” is, but also look at the historical circumstances of the epoch 1960s-present. The avant-garde is conservative in the “reduce, recycle, re-use” sense, not in the Tea Party sense. The avant-garde is a brand, a niche, a circulating stasis. Far from being the domain of youth, today’s avant-garde includes many older artists whose work has been around for decades. Today’s avant-garde is of superior quality but it is not innovative. When innovation is low, quality of execution is high; and vice-versa. The causes for this situation include the emergence of “restoration of behavior” and poststructuralism as dominant theories and the emergence of colleges and universities as primary training for artists.