This study evaluates the life history responses of yellow perch to mass removal and the potential for population recovery. We removed approximately 94% of a perch population from Nepawin Lake, a 35 hectare oligotrophic lake in Algonquin Provincial Park, Ontario, as part of a study designed to enhance the recruitment success of brook trout. Several response variables were examined both before and after mass removal: (1) condition, which includes growth, diet and overall condition responses, and (2) reproduction, which includes size at maturity and fecundity. We examine the question of whether compensatory life history responses in the yellow perch will overcome brook trout predation leading to a reestablishment of a high density perch population. Results showed that prior to the manipulation, perch exhibited a narrow size distribution, high dietary overlap, and low condition, typifying a stunted population. After mass removal, the perch population remained in a narrow size distribution, exhibited decreased growth rates for older age classes, showed increased mean condition and increased consumption of zooplankton in all size classes. Perch also exhibited increased size at maturity and decreased fecundity immediately following the mass removal. A time lag is expected before compensatory recruitment is possible in the population, but it is likely that the perch will recover from the mass removal because of strong age 0+ and 1+ cohorts. However, stunting and bottlenecking may still occur in the population. Continued monitoring and management is necessary to observe further changes to the perch population dynamics in Nepawin Lake.

No description available.

<p>There have been many cases reported of amphibian populations declining. These are often due to anthropogenic factors such as habitat destruction and pollution. However, some eclines have not had an obvious cause and many of these have been investigated and found to be due to pathogenic disease. Batrachochytrium dendrobatidis is a recently described pathogen of frogs. The population declines that have been associated with chytridiomycosis have occurred in relatively undisturbed areas such as national parks. The declines tend to occur at higher altitudes or in colder climates. This is thought to be because of the frog immune system being slower at lower temperatures. This project gives an overview of chytrid infection in the Western Cape and at a small number of sites in the Northern Cape and Eastern Cape.</p>

Yellow perch, Perca flavescens, were collected by night trawling and gill netting at 5 m in a study area near Kintzele Ditch in Indiana waters of Lake Michigan during the months of June through September, 1975. Additional collections made by the Indiana Department of Natural Resources and the U.S. Fish and Wildlife Service using gill nets were included in some aspects of the study.Population characteristics were analyzed and compared to other studies. The rate of growth was significantly greater than in past Great Lakes' populations. The calculated length-weight relationships and growth rates were comparable to those reported by recent studies for southern Lake Michigan. Growth differed between males and females of the same age, and different ages were often represented in the same length interval. Nearly all male yellow perch were mature by age I and 130 mm. About half of the age II females and most at the 200 mm length interval were mature. Sex ratios were variable.Higher catch-per-unit-effort (cpe) was related to warmer water temperatures to the thermocline level. When water temperatures were mixed resulting in low inshore temperatures, cpe values were lower.There existed a great deal of sample variability within and between gear types as a result of seasonal population availability, gear characteristics, and non-random distribution of the population.Trawling, although more efficient than gill netting at sampling total numbers and widest range of lengths, was selective for smaller fish, and gill netting was selective for larger fish. Depth (from 5 m to 18.3 m) and particular gill net methods employed had little effect upon the sizes and length-percent frequency distribution sampled.Great differences between percentage age compositions compiled from trawl and gill net catches reflected the size selectivity of the gears. These results raised questions concerning the validity of management techniques involving percentage age composition and cpe index values to determine relative year class strength.The age groups I and II were represented by the proportion 8:2 (1:11) in the trawl catch which adequately sampled the sizes including the age I and II fish. Further study would be needed to determine the validity and usefulness to management considerations of this method of relative year class strength determinations. Recommendations for additional study were made.

The potential near-shore forage fish populations were investigated by bottom trawling during the months of June through August of 1984-86 in Lake Michigan, near Michigan City, Indiana. Data were collected on the six moat common species including: yellow perch (Perca flavescens); alewife (Aloes pseudoharenqus); rainbow smelt(Osmerus mordax); bloater (Coreaonus,hovi); spottail shiner (Notroois hudsonius); and trout-perch (Perconsis omiscomavcus). Results of the 1984-86 sampling period were compared with data for 1973 in an attempt to document changes in population density, species composition, annual catch, seasonal abundance, and population structure.The total trawl catch for all species increased nearly seven-fold since 1973 even though sample methods and collection effort were unchanged. A dramatic increase in yellow perch abundance was primarily responsible for the elevated levels sampled for all species from 1984-86.The species composition of the catch shifted since 1973. In 1973, spottail shiners were the most abundant species (41%) and trout-perch and alewives were the next most abundant species comprising 20% and 17% of the catch, respectively. Yellow perch, which comprised only 12% of the catch in 1973, increased to 81% of the catch in 1986. Bloater also showed a great increase in relative importance since 1973 when they were rare in the catch. Other species, including alewife, were relatively minor components of the total catch each year from 1984-86. The trawl catch results revealed that alewife and trout-perch declined 71% and 87%, respectively, comparing 1973 with 1984-86. During the same period, yellow perch increased 72-fold and bloater over 3000-fold. By comparison, the spottail shiner population was stable with no long-term changes, but rainbow smelt populations fluctuated widely.Seasonal abundance of adult fish (age I or older) generally decreased from June to August for each fish species and year sampled with the exception of yellow perch which peaked in July of 1973, and in August of 1985-86. Young-of-the-year fish were generally captured in late July and August.Population structure changes were evaluated by examining pooled length-frequency data. Yellow perch length-frequency distributions indicated that strong year classes were produced every year from 1983 to 1986. The 1985 year class was well over twice as large as any of the other years sampled. Spottail shiner and rainbow smelt length-frequency distributions remained approximately stable since 1973, while alewife length-frequency distributions fluctuated annually. Capture of bloaters was almost entirely limited to June, and consisted primarily of age I+ fish in 1984-86.These results reveal significant changes have occurred in the potential near-shore forage fish populations in Indiana waters of Lake Michigan since the early 1970's. Although several factors may be involved in the shifts noted, the major contributing factor is likely predator-prey interactions as a result of salmonid predator density.

This study investigates the status and habitat characteristics of the Cooper's Hawk (Accipiter cooperi), the Red-shouldered Hawk (Buteo lineatus), the Broadwinged Hawk (Buteo platvpterus), and the Red-tailed Hawk (Buteo 'amaicensis) in East-central Indiana to provide information useful for the conservation of these species. Surveys of hawks were conducted using taped Great-horned Owl broadcasts at 350 points between April and July, 1995 and 1996. The relative abundance was estimated using the proportion of area occupied technique. Estimates of the proportion of area occupied by each species ranged from 4% to 34%. Red-tailed Hawks were estimated to occupy 34% of the area surveyed. Estimates of the area occupied by Cooper's Hawks was 8% and by Red-shouldered Hawks was 4%. Broad-winged Hawks only occupied two points, therefore no estimate of the area occupied was determined. Macro-habitat characteristics were quantified for each species within a 0.8-km radius of the center of each occupied area and were compared with randomly selected unoccupied areas. Large forested areas with less human development were most preferred by Red-shouldered and Broad-winged Hawks. Cooper's hawks and Red-tailed hawks were found in a wide variety of habitat types. / Department of Biology

Houses Finches became a breeding species in Indiana in 1981 and subsequently went through a rapid population increase. This study was an investigation of the growth of the House Finch population and its impact on House Sparrows, American Goldfinches and Purple Finches in Indiana. Data from the Annual Christmas Bird Counts of the National Audubon Society (CBC) were used to construct five winter range maps to show the expansion of the House Finch population since 1940. A population density map based on the CBCs of 1988 and 1989 was constructed using birds counted per party hour.CBC data collected during 1965 to 1989 at twelve locations in Indiana were used to track long-term changes in the populations of House Finches, House Sparrows, American Goldfinches and Purple Finches. The number of House Finches counted in Indiana since 1981 increased dramatically. The size of the House Sparrow population appears to have been in a long-term decline for the last 25 years. However, American Goldfinches have, in general, increased in abundance since 1979. The abundance of Purple Finches in Indiana in the winter varies erratically.Observations at backyard feeding stations frequented by House Finches and House Sparrows show that House Finches tend to displace other House Finches more often than would be expected if the displacements occurred in proportion to the frequency at which the birds appear in the population. House Sparrows were found to displace other House Sparrows at a rate which greatly exceeded the expected frequency based on their proportion of the population. Both species tend to avoid interspecific interactions.Field studies in Muncie, Indiana show that House Finches commonly nest in shrubbery and building decorations while House Sparrows often nest in crevices in old buildings and bird houses. No direct competition for nesting sites was observed.Banding studies indicate that during the fall and winter there is a constant turnover of House Finches in Muncie. Using banding data from the U. S. Fish and Wildlife Service it was found that House Finches in the Midwest tend to travel in a southern direction as the season changes from summer to winter and in a northern direction as the season changes from winter to summer. The study shows that House Finches have a strong propensity to return to the same general area each summer. / Department of Biology

This research studied not only the Millennial Generation teachers who have entered the workforce in recent years, but it also compared the perceptions of Black Millennial Generation teachers to those of White Millennial Generation teachers. The intent of this study was to discover whether Black and White Millennial Generation teachers feel prepared to work with diverse groups of students and to reveal additional factors influencing their decisions to remain in education. This study also examined whether there were differences between the perceptions of Black and White Millennial Generation teachers regarding their work/life balance, the amount of support they receive from their administrative team, professional learning opportunities, and other components of their teaching careers. This agenda is relevant because the impact of Millennials on the field of education has only begun to be realized and the percentage of Millennials in the classroom continues to rise. Interviewing six Millennial Generation teachers utilizing a semi-structured interview protocol allowed the researcher to gather data about their perceptions of their ability to work with diverse groups of students and the teaching profession. To make sense of the raw data, a prior-research-driven method was used for data analysis. The Millennial Generation is touted to be the most diverse generation to date. This study found that both Black and White Millennial Generation teachers feel they are able to successfully reach ethnically and socioeconomically diverse groups of students. The subjects for this study reported a high tolerance for and appreciation of ethnic, socioeconomic, and religious diversity.

Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 79-92). / x, 92 leaves, bound ill. (some col.) 29 cm

Nototodarus sloanii is an important component of the Southern Ocean fauna, and the basis of a large commercial fishery. Despite this, much is unknown about the biology of this species. This study examines some aspects of the biology of N. sloanii. Stomach contents analysis identified no significant differences in diet between male and female squid. Sixteen putative species, including 12 identifiable teleosts, 2 crustaceans, and 2 cephalopods were identified in the diet of this species. The euphausid, Nyctiphanes australis was the most important prey item, Lanternfish, Lampanyctodes hectoris, and Pearlside, Maurolicus muelleri, were of secondary importance. Squid were aged using counts of statolith micro-increments and back-calculation from the date of capture showed that hatching occurred between August and February, with a peak in the austral winter/spring and another smaller peak in the austral summer. Growth rate for male squid differed depending on whether squid were hatched in the winter/spring or summer. Growth rates were more variable in the winter/spring-hatched individuals, and they attained larger size than summer-hatched squid. This was not the case for female squid. Mean age for immature winter/spring-hatched squid was significantly higher than for summer-hatched squid, although there was no significant difference in mean mantle length or body mass. No significant differences between mean age, mantle length, or body mass for same-gender mature squid, regardless of hatch season, were apparent. However, mature female squid hatched in the winter/spring season were significantly longer (ML) than mature male squid hatched in winter/spring. No squid was found to be older than 211 days. All squid had started to mature by 91-120 days old and all were fully mature at 180 days. Validation experiments run on juvenile squid using calcein markers were inconclusive, however the increments in the statoliths were very similar to those found in other validated species of ommastrephid squid, thus for the purposes of this study they were assumed to be of daily periodicity. Gladius increments identify a gender difference in growth rate, with female squid having a shorter initial slow growth phase than male squid. Gonadosomatic indices (GSIs) were calculated for male and female squid. These were low (7.12%�0.3% for females and 1.9%�0.2% for males) suggesting that these squid are intermittent spawners. This is further supported by a histological examination, which found germinal cells of different stages present in the same gonad. Lack of mature individuals in this study means that these results are suggestive rather than definitive; more examination of the reproductive process of this squid is required. Histological examination was also used to validate the Lipinski maturity scale for use with this species, while some misidentification occurred the scale is useful to place squid into the broad categories of immature, maturing, or mature. New maturity scales were created for N. sloanii utilising these broad categories. Finer-scale identification is not possible using this scale, as maturation appears to be a continuous process. Morphometric measurements were taken from both hard and soft tissues and were analysed using non-metric multidimensional scaling and analysis of similarity. Divisions were only apparent in the hard structure measurements. They did not appear to be age, dietary or reproductive differences.