1,721,031 research outputs found
Wood Frog and Boreal Chorus Frog Distribution and Habitat Associations in Wapusk National Park, Cape Churchill, Manitoba: 2005 Summary Report
No full textConcern about amphibian populations at a global scale has resulted in recent efforts to establish monitoring programs for amphibians in North America (e.g., North American Amphibian Monitoring Program; Weir and Mossman 2004) and elsewhere, although these monitoring efforts have not been extended to subarctic regions. Distribution, abundance, population dynamics, and habitat relationships of anurans that inhabit subarctic regions are poorly understood, and anuran monitoring protocols developed for temperate regions may not be useful across large roadless areas of northern landscapes. Arctic and sub-arctic regions of North America are also areas predicted to experience changes in climate, and in some areas, have experienced habitat alteration due to high rates of herbivory by breeding and migrating waterfowl, especially snow geese (Chen caerulescens). Environmental and habitat changes may influence the distribution and abundance of anurans that inhabit arctic and subarctic regions (Wassersug 1992, Crump et al. 1999)Andersen, David E; Boal, Clint W; Reiter, Matthew E. (2005). Wood Frog and Boreal Chorus Frog Distribution and Habitat Associations in Wapusk National Park, Cape Churchill, Manitoba: 2005 Summary Report. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/183526
Species Composition, Distribution, and Habitat Associations of Anurans in a Subarctic Tundra Landscape Near Cape Churchill, Manitoba, Canada
No full textDistribution, abundance, and habitat relationships of anurans that inhabit subarctic regions are poorly understood, and anuran monitoring protocols developed for temperate regions may not be applicable across large roadless areas of northern landscapes. In addition, arctic and subarctic regions of North America are predicted to
experience changes in climate and, in some areas, recently have experienced habitat alteration due to high rates of herbivory by breeding and migrating waterfowl. To better understand subarctic anuran abundance, distribution, and habitat associations, we conducted anuran calling surveys in the Cape Churchill region of Wapusk National Park, Manitoba in 2004 and 2005. We conducted surveys along ~1-km transects distributed across 3 landscape types (coastal tundra, interior sedge meadow/ tundra, and boreal forest/ tundra interface) and estimated the probability of detection and density of Boreal Chorus Frogs (Pseudacris maculata) and Wood Frogs (Rana sylvatica). We detected a Wood Frog or Boreal Chorus Frog on 22 (87%) of 26 transects surveyed, and probability of detection varied between years and species and among landscape types. Estimated density of both species increased from the coastal zone inland toward the boreal forest edge. Our results suggest that anurans occur across a wide range of habitats in this subarctic tundra landscape, that there are spatial patterns in anuran abundance, and that considerations for both spatial and temporal variation need to be incorporated into surveys for subarctic anurans.Reiter, Matthew E; Boal, Clint W; Andersen, David E. (2006). Species Composition, Distribution, and Habitat Associations of Anurans in a Subarctic Tundra Landscape Near Cape Churchill, Manitoba, Canada. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/183608
FACTORS AFFECTING DISTRIBUTION AND DETECTION OF BOREAL CHORUS FROGS (Pseudacris maculata) AND WOOD FROGS (Rana sylvatica) AT CAPE CHURCHILL, MANITOBA
No full textAmphibian populations are declining globally (Jennings and Hayes 1985, Beebee
et al. 1990, Blaustein and Wake 1990). Disease, introduced predators, ultraviolet
radiation, pollution, environmental change, and habitat loss and degradation have been
suggested factors responsible for amphibian population declines (Jennings and Hayes
1985, Beebee et al. 1990, Laurance et al. 1996, Pounds et al. 2006). However, the
relative importance of each potential factor is often unknown in specific cases. Because
the processes that underlie amphibian declines are not well understood, collaborative
efforts, such as the North American Amphibian Monitoring Program (NAAMP), have
been developed to collect basic ecological data, and to systematically monitor amphibian
population trends. Despite efforts such as the NAAMP, there are still many areas where
amphibian surveys have not been conducted and little is known about local populations.Mannan, Nicholas R; Perry, Gad; Andersen, David E; Boal, Clint W. (2006). FACTORS AFFECTING DISTRIBUTION AND DETECTION OF BOREAL CHORUS FROGS (Pseudacris maculata) AND WOOD FROGS (Rana sylvatica) AT CAPE CHURCHILL, MANITOBA. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/183533
Effects of source population and holding time on northern bobwhite translocation success
No full textNorthern bobwhites (Colinus virginianus) have become a species of great conservation priority because of widespread and ongoing population declines. Translocations of wild individuals have been readily utilized to re-establish viable populations. Long-distance translocations are becoming increasingly necessary to access a source population with densities high enough to support translocation. Two uncertainties exist regarding the efficacy of long-distance translocations: choosing a source population with adaptations that will be successful in a novel environment and mitigating the stress response common during the translocation process. I translocated bobwhites from the South Texas Plains and the Floridian Coastal Plain to a recipient site in the Floridian Coastal Plain to compare the survival and reproductive success of bobwhites translocated from two different source populations. I also evaluated how varying holding times during the translocation process and using antioxidant-enriched feed for stress mitigation influenced the success of the translocated individuals. Breeding season survival was similar between source populations; however, productivity was lower for the bobwhites translocated from the South Texas Plains. Translocated bobwhites held for 12-14 days had lower survival than those held for < 48 hours and 6-8 days. I observed high rates of mortality during the transport and holding processes, but treatment with an antioxidant-enriched feed prior to capture effectively reduced holding mortalities. Long-distance translocated bobwhites may have the adaptive capacity to be successful in novel environments, but the consequences of translocation stress are detrimental. This knowledge will ultimately inform future translocation practices to better improve ongoing bobwhite restoration efforts.Restricted until 06/2027. To request the author grant access, click on the PDF link to the left
Anti-predatory behavior of northern bobwhite in the rolling plains of Texas
No full textNorthern bobwhites (Colinus virginianus; hereafter bobwhites) are a species of great economic importance but have declining populations range-wide. As a result, bobwhites are a highly researched species. Flight behavior and cover use patterns of northern bobwhites have been examined in several studies, all of which have contributed to a large set of habitat management recommendations for the species. However, the existing data lack quantitative measures of how bobwhites respond to natural threat, not solely direct human disturbance. I examined aspects of bobwhite behavior in response to four threat categories: researcher, hunter, raptor, and mammalian. I found that bobwhite flight distance is best predicted by threat type, covey size, and wind speed. I found that bobwhites flushed by the hunter threat (P = 0.034) and the raptor threat (P < 0.0001) selected for significantly higher visual obstruction at landing sites compared to availability. Raptor-flushed bobwhites also selected for significantly higher shrub density (P < 0.0001) and lower angle of obstruction (P <0.0001) at landing points than what were randomly available. In the process of data collection I also observed bobwhite roost locations (n=24) to have lower visual height obstruction (P = 0.03), lower shrub density (P = 0.02), and higher angles of obstruction (P = 0.005) than bobwhite diurnal locations. My results verify that bobwhite escape strategies and cover use vary among threat types. These results support current management recommendations of creating a patchwork of vegetation covers for bobwhite, but also indicate the importance of understanding of bobwhite behavior to improve management and conservation strategies.
To examine how bobwhites respond to a raptor threat, we used a trained northern goshawk (Accipiter gentilis), a bird often used for falconry. The practice of falconry is over 2000 years old. It is a form of hunting wild quarry in its natural state and habitat by means of a trained raptor. Researchers, specifically when studying wild raptors, have used techniques from falconry and at times used trained raptors for research purposes. Studies with trained raptors have investigated raptor flight characteristics and morphology, behaviors, predator ecology, and their effect on prey ecology and behavior. Despite the potential applications of falconry within the field of wildlife research, trained raptors are an under-used resource; this is 1 of only 2 studies to use a trained raptor to investigate prey species behavior in a non-captive setting. I review the methods and results for studies involving trained raptors within the field of wildlife research. I then discuss the logistical constraints and limitations of working with a raptor in a research setting. Finally, I offer suggestions for future research using trained raptors.This thesis won 1st Place in the Texas Tech University Outstanding Thesis and Dissertation Award, Biological Life Sciences, 2013.Embargo status: Restricted to TTU community only. To view, login with your eRaider (top right). Others may request access exception from the author by clicking on the PDF link to the left
Assessing the influence of wind turbines and land-use on mortality risk of avian species on the Llano Estacado with emphasis on birds of prey
No full textWind energy is a burgeoning industry on the Llano Estacado of Texas and could negatively affect the local avian community if birds collide with turbines or avoid previously occupied habitat. The purpose of my thesis was to explore the relationship between wind energy, land-use, and bird populations on the Llano Estacado. I assessed the potential effects of wind energy development on three aspects of avian ecology. First, I conducted small-scale point count surveys during the breeding season as well as broad-scale year-round point counts to compare avian diversity and species abundance one year before, and two years after, wind turbine construction. Breeding bird diversity differed significantly among my three years of study (November 2011-August 2014) but I could not attribute this variation to turbine construction. Rather, evidence suggested breeding diversity may be best explained by inter-annual variation of weather patterns on the study area. Diversity also differed significantly across years for broad scale point counts. Additionally, most species and most seasons (e.g, Winter, Spring, Summer, Fall) showed significant differences in abundance across study years, but many of these differences may also be best explained by interannual variation in weather conditions. Second, I surveyed raptors along a 154 km transect each month for one year to evaluate raptor resource selection of local land-use types (cotton, grain agriculture, rangeland, non-grazed grassland) to assess which land-use types may present higher or lower collision risk for raptors. My results indicated species-specific and season-specific patterns were apparent. Species did not use the land-use categories in proportion to availability on the study area. Generally, non-grazed grasslands were used at a greater proportion than expected and cotton agriculture was used less than expected based on availability on the landscape. Third, I studied the breeding ecology of the American Kestrel (Falco sparverius). Specifically, I assessed kestrel nest selection in relation to proximity of five wind turbines located at the Reese Technology Center in Lubbock County, Texas. American Kestrels readily accepted and successfully nested in newly installed nest boxes. Interestingly, 4 of 10 nesting pairs (40%) across two years produced double broods, which is uncommon for the species. The results from my proximity analysis suggested kestrels did not have an affinity for, or an avoidance of, recently constructed wind turbines. My results suggest that overall avian risk from small-scale turbine construction may be difficult to discern due to the effects of weather. Additionally, my results show that raptor-turbine collision risk may be higher if turbines are constructed on non-grazed grassland and lower when turbines are constructed on cotton fields
Post-breeding public information use in a ground-nesting songbird community
No full textOrganisms constantly make decisions that can strongly affect their fitness. For birds, the territory an individual chooses to breed in can have large and direct effects on their reproductive success. Birds can assess territory quality to make settlement decisions by using information obtained from social cues emitted by other organisms. Public information (PI) from performance-based social cues reveals territory quality by advertising the current inhabitants’ reproductive success. I studied PI use in the Veery (Catharus fuscescens) and its effect on avian community responses by conducting a playback experiment. I hypothesized that Veery fledgling vocalizations present during the post-breeding season are PI cues used by Veeries and other ground-nesting songbirds (i.e., Ovenbirds [Seiurus aurocapilla]) for territory establishment in subsequent breeding seasons. Moreover, I hypothesize that ground-nesters integrate multiple social cues sampled throughout the breeding season when selecting future breeding territories. To test this, I played Veery fledgling vocalizations and silent controls at plots during the post-breeding season in 2009 and 2010. I also played chipmunk vocalizations (nest predators, i.e., social cues indicating lower quality territory options) at half of these plots during the pre-breeding season. Response data (nest distances to nearest plot, nest counts at each plot, and nest initiation dates) were collected during the following breeding seasons as well as breeding songbird abundance for both ground- and canopy-nesters. My results show that both Veeries and Ovenbirds were more likely to settle in fledgling treatment plots compared to silent controls. Similarly, both ground- and canopy-nesters were more abundant at fledgling treatment plots relative to silent controls. Ovenbirds appeared to assess territory quality by integrating multiple social cues for territory establishment, but Veeries did not. My study demonstrates that post-breeding PI reaches heterospecifics by influencing territory establishment among both ground- and canopy-nesters. This study is the first to test if songbirds integrate social information from multiple sources throughout the breeding season for territory selection
The structural impacts of wildfire and defoliation on Mexican spotted owl (Strix occidentalis lucida) nesting habitat
Full text linkDisturbance plays a major role in shaping forest structure and composition, but disturbance regimes across the globe are changing because of human activities. Structure-altering disturbances, including defoliating insect outbreaks and fire, historically occurred in southwestern forest systems, but anthropogenically driven disturbance regime change is rapidly reshaping spatial and temporal patterns of these historical disturbances. These forests are trending towards increased defoliator outbreaks and stand-replacing wildfire due to fuel accumulation and/or climate change. Despite the increasingly prominent presence of defoliation and fire in Mexican spotted owl (Strix occidentalis lucida) forest habitat, there is little understanding of how these disturbances effect the threatened subspecies through altered forest structure. No studies to date have examined how defoliation affects the owls, and in comparison to the two other spotted owl subspecies, the relationship between fire and the Mexican spotted owl is poorly studied, despite its range being projected to experience the largest increase in percent burned area of the three subspecies by the 2080s. To help fill these knowledge gaps, I addressed the impacts of both fire (at varying severity and time since fire—up to 99 years) and defoliation (via Janet’s looper; Nepytia janetae) on forest structure in mixed-conifer forest of the Sacramento Mountains, South-Central New Mexico. I quantified the structural response in burned, defoliated, and control areas, comparing the forest structure in these areas to structural thresholds defined as desired for Mexican spotted owl nesting habitat, and I analyzed spatial patterns of successful nest locations in response to a 2007 Janet’s looper outbreak. In line with the evolutionary history of this landscape, forest that burned at low to moderate severity provides and maintains adequate Mexican spotted owl nesting habitat structure soon after fire, but high severity fire would take greater than 100 years to recover to desired levels for nesting. Structure in a recently (13 years) defoliated area was suitable for nesting, but the spatial patterning of nest locations 1-4 years after the defoliation event demonstrated an immediate negative response to the disturbance—a possible result of temporal discrepancy between nest site data and forest structure data, a sampling bias against more severely defoliated areas, or a response to other disturbance. Ultimately, forest structure that is understood to support Mexican spotted owl nesting will be promoted by the restoration of frequent, low-to-moderate severity fire and minimal activities that incur large structural changes, such as stand-replacing fire and logging.Embargo status: Restricted until September 2022. To request an access exception, click on the PDF link to the left
An assessment of survey methodology, calling activity, and habitat associations of wood frogs (rana sylvatica) and boreal chorus frogs (pseudacris maculata) in a tundra biome
No full textThe tundra biome near Cape Churchill, Manitoba is being influenced by global climate change and herbivory from an increasing population of light geese. These environmental changes may impact anuran populations, although little is known about population trends in anurans in the region. The isolation of the region may render traditional anuran survey methods ineffective. I tested two methods of surveying for two anuran species, boreal chorus frogs (Pseudacris maculata) and wood frogs (Rana sylvatica). I solicited calls from non-calling anurans by manually broadcasting conspecific advertisement calls, and I used automated audio recorders to increase survey coverage. I detected 0.38 additional wood frogs per survey when broadcast calls were employed, compared to surveys without broadcasts. I was unable to detect additional boreal chorus frogs by broadcasting conspecific advertisement calls. Using automated audio recorders, I was able to identify anuran presence in a radius of 100 m, but detections of wood frogs were low compared to manual surveys. I suggest that broadcasts of wood frog advertisement calls be implemented into surveys for wood frogs in the tundra biome, and that additional research is necessary to determine whether solicitation can be used to increase detection of other anuran species.
Chapter II
Little information exists regarding wood frogs (Rana sylvatica) and boreal chorus frogs (Pseudacris maculata) in the tundra biome, where environmental conditions differ from most of the rest of their breeding ranges. Understanding anuran calling patterns is essential to most anuran survey methodology. During the summer of 2007, I placed automated audio recorders at anuran breeding locations and recorded number of calling anurans near Cape Churchill, Manitoba. I used data loggers and automated call recorders to document date, time of day, temperature, and relative humidity. Automated recorders detected wood frogs between 30 May and 2 July 2007, and boreal chorus frogs between 11 June and 5 July 2007. Calling activity of both wood frogs and boreal chorus frogs was influenced by temperature and day of the year (DOY). Calling activity of boreal chorus frogs was also influenced by time of day and relative humidity. Understanding calling patterns with respect to weather patterns will facilitate future monitoring.
Chapter III
Anuran populations in the subarctic tundra biome in northern Manitoba are being impacted by multiple factors, including vegetation changes resulting from foraging pressure by an increasing population of light geese. During the summers of 2006 and 2007, I surveyed 204 potential anuran breeding locations in two study plots in the tundra biome within Wapusk National Park, Manitoba, Canada to assess anuran habitat associations. I examined habitat selection and associations of wood frogs (Rana sylvatica) and boreal chorus frogs (Pseudacris maculata) with regard to vegetation and water quality. Both wood frogs and boreal chorus frogs selected sites where vegetation was taller and had a higher composition of sedge (Carex spp.) and willow (Salix spp.). Both species also selected sites with relatively low pH and conductivity (TDS). An index of goose herbivory was negatively correlated with vegetation height and cover by sedge and willow and positively correlated with pH and conductivity. Both wood frogs and boreal chorus frogs were found more commonly in sites with less evidence of recent goose herbivory
Analysis of motion-captured pictures located on man-made water sources in the Southern High Plains of West Texas
No full textMan-made water sources that harvest rainwater or provide water by using different varieties of pumping methods, have been widely used for managing wildlife in the arid United States since the 1940’s. One major concern with man-made water sources is that they are a known location to both predator and prey species and may cause increased mortality of prey species. Although a highly contested topic, predation at man-made water sources remains a minimally studied subject. I monitored 13 man-made water sources with motion sensing cameras over a 4 year period in the sand-shinnery oak/sand sagebrush ecosystem on the High Plains of Texas to investigate temporal patterns of visits by predator and prey species. I collected 1,887,902 digital images over 4,572 trap days. I recorded all species detected, but only conducted analysis for select species of interest. These included all raptors, mesocarnivores, mule deer (Odocoileus hemionus), pronghorn (Antilocapra americana), and the lesser prairie-chicken (Tympanuchus pallidicinctus). I conducted a cluster analysis to identify biologically relevant time frames of water source visits and, within each time frame, I assessed species visit rates and overlap among predator and prey species. I found evidence of predator avoidance by the prey species based on time of water source visit, except for mule deer. To scrutinize the data closer and find further evidence, I used a non-linear quantile regression analysis on the data to use in tandem with the cluster analysis. I used the 99th quantile to examine the extreme values and found evidence of predator avoidance by all three prey species at man-made water sources.
The main species of concern on the site is the lesser-prairie chicken and, therefore, more research was conducted to investigate temporal patterns of visitation and to identify factors influencing their visitation. This region of my study area is predicted to have increased frequency of drought conditions through time concluding in less precipitation and higher temperatures on average. The only reliable surface water in the study area is provided by man-made water sources, mainly used for livestock production. Three life stages were created a priori and were defined as 4 month blocks: breeding, post-breeding, and winter. I examined patterns of lesser prairie-chicken visits to man-made water sources in context to temperature, precipitation, dew point, year, and life stage. An analysis of covariance was used to assess the influence of categorical and continuous variables as drivers of use. Dew point was the single variable that best predicted water use by lesser prairie-chickens. However, dew point was also highly correlated with life stage
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