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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Northern bobwhite (Colinus virginianus) breeding season calling behavior and roost site selection in a working agricultural landscape in Clay County, Mississippi

Lappin, Olivia A 12 May 2023 (has links) (PDF)
Research on northern bobwhite calling behavior and roosting ecology during the breeding season has received limited attention. However, variability in calling rate in response to conspecifics and environmental factors may affect avian monitoring strategies. We conducted 10-minute breeding season surveys (April-August) on B. Bryan Farms, Mississippi, from 2021-2022 to evaluate the impact of conspecifics and environmental covariates on male bobwhite calling rate. We observed a positive linear effect of conspecifics and temperature on calling rate. We did not find sufficient evidence to support a relationship between calling rate and cloud cover or barometric pressure. We also analyzed breeding season third-order roost site selection and found selection against bare ground and a quadratic relationship with litter and average vegetation height during roosting activity. It is also important for managers to consider all conditions of the environment and habitat requirements during every season for population persistence, including breeding season roost cover.
2

Feeding strategies of Bewick's swans (Cygnus columbianus bewickii) in winter

Bowler, Jonathan Mark January 1996 (has links)
No description available.
3

The life history of the American crow Corvus brachyrynchos Brehm

Good, Ernest Eugene January 1952 (has links)
No description available.
4

Spatial distribution in a turkey vulture roost

Nauman, Lyle Edward January 1965 (has links)
No description available.
5

The role of energy expenditure in roost selection by bats

Marroquin, Cynthia Maria January 2020 (has links)
No description available.
6

Estimating Distribution and Abundance of Rio Grande Wild Turkeys in South Texas

Caveny, Robert J. 2009 August 1900 (has links)
Sustainable management of wildlife populations relies on accurate estimates of population size as harvest recommendations are dependent on estimates of sustainable surplus. Techniques for surveying wild turkey populations in Texas are constrained by land access issues, requiring that new methods be developed for population monitoring. I evaluated a combined approach using patch-occupancy modeling at broad spatial scales and intensive double observer roost surveys at local scales to estimate Rio Grande wild turkey (Meleagris gallapavo intermedia) distribution and abundance. I flew replicated aerial surveys during 2007 and 2008 to evaluate distribution of Rio Grande wild turkeys in the south Texas Coastal Sand Plains. I used a double observer approach to estimate local scale abundance. I used a single observer approach to estimate temporal variation in roost use. Detection probabilities from aerial surveys ranged between 0.24 (SE = 0.031) and 0.30 (SE = 0.083). Spatial parameters that influenced distribution of wild turkeys included size of suitable roosting habitat patches and distance to the nearest suitable roosting habitat. I conducted 100 inter-patch double observer roost counts, with counts ranging between 0 to 183 individuals. Average detection probabilities for observers were ~0.90. Roost level occupancy was ~0.84 with detection probabilities between 0.69 (SE = 0.107) and 0.79 (SE = 0.091). Based on my results, aerial surveys combined with local abundance estimation may be one viable alternative to monitor turkey populations over large spatial scales, by reducing overall survey effort without loss of estimated precision.
7

Causes and Consequences of Fission-Fusion Dynamics in Female Northern Long-Eared Bats, Myotis septentrionalis

Patriquin, Krista 23 May 2012 (has links)
Individual costs and benefits of living in groups vary with group size, stability, and composition. Investigations of these features of group living have lead to the recognition of a variety of social structures. Although many studies have examined social structure in animals with long-term, stable groups, little is known about groups with highly variable group size and composition, such as fission-fusion dynamics. In this thesis I examined the causes and consequences of fission-fusion dynamics by exploring the socioecology of female northern long-eared bats, Myotis septentrionalis. Like many temperate bats, female northern long-eared bats show natal philopatry to summer areas. During this time, they live in groups with fission-fusion dynamics as individuals move among a network of roosts and roost-groups. To examine the causes of fission-fusion dynamics, I examined why females switch roosts. To address the consequences of these dynamics, I asked whether females could form stable relationships, and what factors might explain these relationships. I was able to identify the possible causes and consequences of fission-fusion dynamics that had not yet been explored in bats. I demonstrated that fission-fusion dynamics may be explained, at least in part, by changes in ambient conditions that prompt frequent roost-switching. Despite the highly dynamic nature of these groups, females formed long-term social relationships that were based in part on age and genetic relatedness. These findings have potential consequences for the evolution of social behaviour within groups, such as cooperation and nepotism. My work also raised several questions that require further examination to fully understand the evolution of fission-fusion dynamics. For example, the question remains whether species or sympatric groups of conspecifics with different degrees of roost-switching show the same social structure. By answering these questions, we can gain a better understanding of the causes and consequences of fission-fusion dynamics across species of bats. Once this is achieved, we can then look for parallels with other taxa to answer questions about the evolution of these dynamic systems.
8

Spectral and temporal characteristics of echolocation calls in pregnant and lactating big brown bats / Echolocation in pregnant and lactating big brown bats

Clarke, Alexa January 2023 (has links)
While they are pregnant and rearing pups, bats continue to leave their roosts to forage for food. Many bats use echolocation vocalizations as part of this process. Other mammalian species including primates experience changes in vocal characteristics during pregnancy and lactation. As echolocation is a vital tool for spatial navigation and prey detection in most bats, investigating echolocation characteristics during pregnancy through lactation may provide new insight into how reproduction, pregnancy and pup rearing influence vocalizations. We measured changes in mass and recorded echolocation calls of pregnant (n = 21) and non-pregnant (n = 2) female wild-caught big brown bats (Eptesicus fuscus) released by hand into roost emergence-like flight. Recording began ~15 days prepartum and ended when the last bat reached 34 days postpartum, when pups were expected to be weaned. Analyses were completed using MATLAB and R, primarily with repeated measures ANOVAs focused on echolocation calls present in the ~562 ms before and ~562 ms after take-off. Based on vocal changes experienced by humans during pregnancy and post-birth, correlations found between bat echolocation call characteristics and the effects of differences in mass on bat echolocation, we predicted that female bats in late-stage pregnancy would emit calls of shorter duration, longer pulse interval, narrower bandwidth, and lower centroid frequency compared to calls emitted by the same bat post-parturition and compared to non-pregnant bats, while source level remained unchanged. We found that pulse interval and source level did not change while pregnant/lactating or control bats were in flight, and that increases in call duration and decreases in centroid frequency and bandwidth in flight began in pregnancy and continued through the lactation period while remaining unchanged for the control bats. / Thesis / Master of Science (MSc) / The goals of this study were to see if big brown bats change the way that they echolocate while they are pregnant and/or nursing pups, and what changes occur. We did this by recording the vocal sounds bats made while they were pregnant and after they had given birth, and looking to see if there were any changes in the duration of echolocation calls, the time between individual sounds, the range of sound frequencies in each call, the central sound frequency in each call, and each call’s sound pressure level over this time and compared to non-pregnant/nursing female big brown bats. We found that echolocation call duration increases over pregnancy and nursing pups, while frequency range and the centre frequency decreases.
9

Bat Habitat Use and Roost Tree Selection for Northern Long-eared Myotis (Myotis septentrionalis) in North-Central Ohio

Krynak, Timothy J. 02 September 2010 (has links)
No description available.
10

Day-roosting Social Ecology of the Northern Long-eared Bat (Myotis septentrionalis) and the Endangered Indiana Bat (Myotis sodalis)

Silvis, Alexander 08 December 2014 (has links)
Day-roost use by northern long-eared bat (Myotis septentrionalis) maternity colonies on the Fort Knox military reservation, Kentucky, USA, resulted in formation of non-random networks of roosts that exhibited a trend toward centralization. Centralization of day-roost networks was reflected in the social structure of colonies, which were characterized by dense associations among individuals within colonies. Social structure varied among colonies and appeared to be related to reproductive condition; colonies exhibited greater cohesiveness during parturition and lactation. Northern long-eared bat maternity colonies appeared to be exclusive, occupying distinct roosting areas with one or several areas receiving intense use. Day-roost removal simulations suggested a linear relationship between colony fragmentation and roost loss, and that loss of >20% of roosts is required to initiate colony fragmentation. Experimental hierarchical removal of day-roosts yielded results consistent with simulations, as removal of the single most-central (primary) roost had no impact on colony fragmentation, whereas removal of 24% of less-central (secondary) roosts resulted in partial network fragmentation. Patterns of colony day-roost and space use were similar pre- and post-removal treatments. Day-roost removal did not alter the number of roosts used by individual bats, but distances moved between roosts were greater in the secondary roost-removal treatment group. Day-roost characteristics largely were consistent pre-post treatment for both treatment groups. Historical data from an Indiana bat (Myotis sodalis) maternity colony revealed that this species also exhibits a non-random social assorting dynamic. Non-random social assortment resulted in a closely connected centralized network of day-roosts. Individuals within the Indiana bat maternity colony exhibited close social connections with colony members, but subgroups likely existed within the colony. Indiana bat day-roosting ecology appears flexible, as patterns of roost and space use differed substantially between years. Development of specific, but tactical, management approaches for individual colonies of both northern long-eared and Indiana bats may be possible. Such approaches would allow land managers to manage for both northern long-eared bat habitat and other objectives. However, the nature of targeted management approaches employed likely will depend on the unique forest context and dynamic within which individual colonies reside. / Ph. D.

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