276 research outputs found

    Winter Ecology of Cooper’s Hawks on Ames Plantation, Tennessee

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    Cooper’s hawks (Accipiter cooperii) were listed by Ganier (1933) as fairly common permanent residents of western Tennessee during the early 1900’s, but populations declined during the 20th Century presumably because of habitat changes, shooting, and effects of pesticides on reproduction (Newton 1979). Breeding bird survey data for Tennessee suggest that Cooper’s hawk populations are increasing (+4.6% increase/year, 1966-2000), although sample sizes are too small for significant trends (P = 0.39, Sauer et al. 2001). Nicholson (1997), in the Tennessee Breeding Bird Atlas completed during the early 1990\u27s, still described Cooper’s hawks as uncommon permanent residents. At the same time Cooper’s hawk populations appeared to be increasing, northern bobwhite (Colinus virginianus) populations were declining precipitously (-3.7 % decrease/year in Tennessee, 1966-2000; Sauer et al. 2001). Many quail biologists have suggested that the decline in quail populations may in part be linked to increasing avian mortality from increasing raptor populations (Hurst et al. 1996, De Maso et al. 1997, Rollins and Carroll 2001). The objectives of the hawk project on Ames Plantation were to describe Cooper’s hawk winter ecology, to describe seasonal patterns of raptor abundance and to gain breeding season data for Cooper’s hawks. The study area was Ames Plantation, Tennessee located in southwestern Tennessee. Ames Plantation is comprised of a variety of covertypes including hardwood forests, mixed forests, pine forests, crop fields, old fields, native warm season grasslands, hardwood conversion areas (areas consisting of savannahs where hardwood forests had been recently harvested, cleared of treetops and trunks, with only a few live trees remaining/ha), and fencerows. We trapped Cooper’s hawks with bal chatri traps baited with house sparrows(Passer domesticus) and fitted hawks with radio transmitters. Using radio telemetry, Global Positioning Systems (GPS), and Geographical Information System (GIS) procedures, diurnal and roost locations were obtained for 5 Cooper’s hawks. To account for telemetry locational errors, diurnal habitat use was determined by delineating covertypes within 50-m-radius circles around each daytime location. The composition of available habitat was also described within 50- m circles delineated around a systematic grid of random points. Habitat use was examined with compositional analysis (Aebischer et al. 1993) and chi-squared analysis (Neu et al. 1974). Logistic regression models were developed to identify the key habitat features that discriminated between roost locations and random sites. A 40-km raptor survey was conducted weekly during winters 1999/2000 and 2000/2001 to determine relative raptor abundance and species composition on Ames Plantation. All species seen or heard at each point and between points were recorded. Nonparametric statistics (Kruskal-Wallace H Tests) were used to compare the winters of 1999/2000 and 2000/2001, leaf-on and leaf-off surveys, and surveys on and off the field trial area. Nest observations and measurements were taken at 4 Cooper’s hawk nests, 4 redtailed hawk (Buteo jamaicensis) nests, and 1 red-shouldered hawk (Buteo lineatus) nest over two breeding seasons (2000 and 2001). A nest camera was set up at 1 red-tailed hawk nest for 2 days and 1 Cooper’s hawk nest for 2 days. We trapped for 533 trap hours on 34 days in winter 1999/2000 and 1,729 trap hours on 53 trap days in winter 2000/2001. We captured 35 raptors, including Cooper’s hawks, American kestrels (Falco sparverius), barred owls (Strix varia), northern harriers (Circus cyaneus), red-tailed hawks, red-shouldered hawks, and sharp-shinned hawks (Accipiter striatus). Nine Cooper’s hawks were trapped in winter 1999/2000 (59 h/capture) and 2 Cooper’s hawks in winter 2000/2001 (865 h/capture). Based on capture success, Cooper’s hawk abundance appeared to be much lower in winter 2000/2001 than in winter 1999/2000. The home range of the 1 male Cooper’s hawk tracked in the winter was 331 ha (95% minimum convex polygon) and the mean size of female home ranges was 836 ha and ranged from 8 ha to 2,529 ha. Diurnal winter habitats used by Cooper’s hawks were ranked in order of most preferred to least preferred as follows: Forests \u3e Edge \u3e Field \u3e Other, based on the compositional analysis (l=0.0722, F=12.84, P=0.0322; MANOVA). Cooper’s hawks used forests more than expected and fields less than expected compared to their availability (N=458, c2=68.76, df=8, P\u3c0.0001; Neu et al. 1974). Twenty-two roost sites were located in 1999/2000 and 34 roost sites were located in 2000/2001. Some of the roost sites were used repeatedly. Vertical cover (P=0.0332), canopy cover (P=0.0030), and canopy cover variance (P=0.0353) were greater in roost sites than random sites, whereas the height of the overstory (P=0.0674) was (marginally) lower in roosts than in random sites. Edges, fencerows, and pines were used more than expected for roosting, while hardwood stands and hardwood conversion areas were used less than expected (c2=30.27, P=0.0001). Radio-tagged Cooper’s hawks emerged from the roost site on average 38 min before sunrise and changed roost sites during the night 12.5% of the time. Cooper’s hawks roosted in dense honeysuckle (Lonicera japonica), briar (Rubus alleghaniensis), and cedar thickets (Juniperus virginiana) near the ground under canopies that were highly variable. A total of 1,671 individual raptors were recorded during 47 surveys (31 winter surveys). Red-tailed hawks (on average 4 - 14.5 birds were detected per survey by month) were the most abundant species while American kestrels (0 - 2.3), northern harriers (0 - 1.5), and red-shouldered hawks (0 - 4.3) were detected less. Cooper’s hawk (0 - 1) and sharp-shinned hawks (0 - 0.5) were detected the least. Total raptor abundance (all species) and red-tailed hawk abundance were greater in the second year (winter 2000/2001) than the first year (winter 1999/2000). Greater red-tail abundance the second winter likely occurred in response to the colder winter temperatures. Total raptor abundance, northern harriers, and red-tailed hawks were detected more on the field trial course, while American kestrels and red-shouldered hawks were detected more off the field trial course. The detection rate of Cooper’s hawks and sharp-shinned hawks averaged about 0.5 hawks per survey- too low to detect differences between years or on/off the field trial area. Visible areas along the 40-km survey route totaled 258 ha. Out of 4 Cooper’s hawk nests, 2 were confirmed to have failed while the other 2 have an unknown fate, but activity at late dates in the breeding season suggest a successful nesting effort. Out of 4 red-tailed hawk nests, 1 was confirmed successful, 1 was confirmed to have failed, 1 was probably successful, and 1 had an unknown fate. The success of the red-shouldered hawk nest is also unknown. The averages for the 4 Cooper’s hawk nests are as follows; nest height, 16.55 m; nest tree diameter, 53.08 cm; vertical cover, 6.06%; canopy cover, 48.8%; and basal area 30.58 m2/ha. The averages for the 4 red-tailed hawk nests are as follows; nest height, 18.7 m; nest tree diameter, 49.83 cm; vertical cover, 11.94 %; canopy cover, 62.73 %; and basal area 19.06 m2/ha. The measurements for the red-shouldered nest are as follows; nest height, 15 m; nest tree diameter, 53.75 cm; vertical cover, 12.5 %; canopy cover, 49.22 %; and basal area 34.39 m2/ha. Cooper’s hawks were found to primarily use forests in the winter at Ames Plantation. However, Cooper’s hawks and northern bobwhites occupied similar habitats (old fields and forest edges with a dense understory of honeysuckle and briars) a significant portion of each day. Prey remains (n = 19) from Cooper’s hawks were primarily passerines (n = 10), morning doves (Zenaida macroura) (n = 4), and northern bobwhite (n = 4). In both winters, radio-tagged Cooper’s hawks moved from Ames to a nearby plantation to prey on pen-reared quail that were released for weekend hunts

    Strengthening Civic Commitment at Winona State University: Evaluating the Past and Celebrating the Future

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    Upon arriving at the American Democracy Project National Meeting Concurrent Session in San Antonio Texas, Laura Lake, Courtney Juelicj and Alexandra Griffin will be presenting along side Dr. Kara Lindaman, on the topic of Stengthening Civic Commitment at Winona State University: Evaluating the Past and Celebrating the future. In addition to the twenty-minuet presentation, students will be Leading the National Issure Forum delebrative dialogue, Shaping our Future: How should Higher Education Help Us Create the Society We Want? This session is a presentation on the National Information Forum that these students organized and moderated for in April 2012, in honor of President Judith Ramaley\u27s retirement. The students will also be attending sessions to enhance their education and experience in democratic processes and participatiion and to have the opportunity to network and learn from professionals in many different fields of their interests. Our faculty sponsor did not require a final repor

    Growing Social Inequalities in Youth Civic Engagement? Evidence from the National Election Study

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    Social class differences in civic engagement persist for both youth and adults. Although empirical evidence is mixed, several recent social changes pertaining to youth suggest that social inequalities in civic engagement may be growing over time for young people. Using data from the National Election Study, we compared trends for youth and older adults of varying education levels and tested the hypothesis of an increasing educational disparity in youth political participation. Results for voting supported our expectations: declines over time were found for less-educated youth only. Unexpectedly, participation in other political activities for more-educated youth declined more over time compared to other groups. Our findings highlight the need to create equal opportunities for youth civic engagement across social groups

    Exploring the Tensions Between Narrative Imagination and Official Knowledge Through The Life of Pi

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    This presentation was given during the Curriculum Studies Summer Collaborative

    Dark Matter Disc Enhanced Neutrino Fluxes from the Sun and Earth

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    As disc galaxies form in a hierarchical cosmology, massive merging satellites are preferentially dragged towards the disc plane. The material accreted from these satellites forms a dark matter disc that contributes 0.25 - 1.5 times the non-rotating halo density at the solar position. Here, we show the importance of the dark disc for indirect dark matter detection in neutrino telescopes. Previous predictions of the neutrino flux from WIMP annihilation in the Earth and the Sun have assumed that Galactic dark matter is spherically distributed with a Gaussian velocity distribution, the standard halo model. Although the dark disc has a local density comparable to the dark halo, its higher phase space density at low velocities greatly enhances capture rates in the Sun and Earth. For typical dark disc properties, the resulting muon flux from the Earth is increased by three orders of magnitude over the SHM, while for the Sun the increase is an order of magnitude. This significantly increases the sensitivity of neutrino telescopes to fix or constrain parameters in WIMP models. The flux from the Earth is extremely sensitive to the detailed properties of the dark disc, while the flux from the Sun is more robust. The enhancement of the muon flux from the dark disc puts the search for WIMP annihilation in the Earth on the same level as the Sun for WIMP masses < 100 GeV.Comment: 7 pages, 4 figures, added a short paragraph to the discussion section, conclusions unchanged, published versio

    The Effects of Adolescent Heavy Drinking on the Timing and Stability of Cohabitation and Marriage

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    Based on prospective British Cohort Study data, adolescent alcohol use predicted the timing and stability of committed partnerships between 16 and 34 years (n = 3278; 59% female). Propensity score methods balanced age 16 heavy drinkers (32.4%) and nonheavy drinkers on a range of relevant risk factors assessed in infancy and childhood. Adolescent heavy drinking predicted having ever cohabited, earlier transitions into cohabiting and marital relationships, more breakups, and an increased likelihood of divorce. Gender and social class moderated these relationships; heavy-drinking working-class males were especially likely to cohabit and to experience early entry into cohabitation and marriage. Implications for practitioners focus on the benefits of reducing adolescent heavy drinking and precocious transitions to committed partnerships
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