Theses and Dissertations at Montana State University (MSU)
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733
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Item Fatal attraction for an imperiled songbird: is cropland in the northern Great Plains an ecological trap for breeding thick-billed longspur?(Montana State University - Bozeman, College of Agriculture, 2022) Swicegood, Amber Elizabeth; Chairperson, Graduate Committee: Lance McNewThick-billed longspur (Rhynchophanes mccownii) populations have declined 4% annually during the past 50 years. This species nests in recently disturbed or sparsely vegetated patches within native mixed-grass prairie and is also known to occur in crop fields in northeastern Montana during the breeding season. Maladaptive habitat selection may result in crop fields operating as ecological traps, but information on thick-billed longspur use of and demography in crop fields are lacking. We hypothesized that crop fields provide cues for territory selection, but frequent human disturbance and increased exposure to weather and predators should result in reduced reproductive success relative to native grassland habitats. To address this hypothesis, we 1) used dynamic occupancy models to compare arrival times of territorial male longspurs using data collected with autonomous acoustic recorders, 2) used open population distance sampling models to compare trends in longspur abundance over the breeding season, 3) compared indices of nest density and number of young fledged, and 4) used nest survival models to compare survival rates of nests between crop and native sites. Arrival times were similar in both site types and occupancy ranged from 0.52 + or - 0.17SE on April 7 to 0.99 + or - 0.01 on April 30. Bird abundances appeared to be mediated by vegetation biomass and drought conditions. Standardized nest densities were 0.15 + or - 0.22SD and 0.23 + or - 0.32 nests/hour/plot in crop and native sites, respectively; the number of young fledged per successful nest was similar in crop and native sites and averaged 2.9 + or - 0.18SE. Nest survival was similar in crop and native sites and averaged 0.24 + or - 0.03 SE (n=222 nests). The data did not support our ecological trap hypothesis: longspurs did not exhibit a clear preference for crop sites and reproductive output was not significantly reduced. Our results suggest that crop fields may expand nesting opportunities for thick-billed longspur in a region where native habitat may be limited.Item Snowshoe hare habitat use and silvicultural influences in the Greater Yellowstone Ecosystem(Montana State University - Bozeman, College of Agriculture, 2019) Kurzen, Mark Daniel; Chairperson, Graduate Committee: Bok SowellSnowshoe hares (Lepus americanus) are the main prey base of the Canada lynx (Lynx canadensis) and are an important food source for many forest carnivores. Snowshoe hare research in the Greater Yellowstone Ecosystem is lacking and current research conclusions differ in regards to the types and ages of forests that snowshoe hares prefer. The US Forest Service has implemented limitations and prohibitions on silviculture in this area based on previous snowshoe hare studies. However, some research in the Greater Yellowstone Ecosystem suggests that regenerating lodgepole pine (Pinus contorta) stands that are associated with silviculture benefit snowshoe hares. We implemented three snowshoe hare use indices in southwest Montana within a portion of the Custer-Gallatin National Forest during 1999-2012 to assess snowshoe hare use of forest cover types in Greater Yellowstone Ecosystem. Our study area was located in a designated US Forest Service timber management area where a history of silviculture has resulted in a heterogeneous landscape of multiple successional stages intermingled with other old growth stands. We analyzed 11 years of snowshoe hare pellet plot surveys using linear mixed models and AIC c model selection. Our results suggested that the understory conifer species was the best predictor of use and that the youngest two classes of regenerating lodgepole pine stands had the greatest snowshoe hare use. We analyzed 13 years of snowshoe hare track counts on roads within our study area using Chi-squared goodness-of-fit tests based on proportional road segment lengths and the associated cover types. We observed the greatest snowshoe hare habitat use in the youngest two classes of regenerating lodgepole pine stands. We live-trapped snowshoe hares for one winter in our study area and observed the greatest number of hares captured per night in the youngest lodgepole pine stands. The findings from our 13 year study suggest that snowshoe hare use was greatest in early successional lodgepole pine forests that were approximately 30-60 years old and associated with clear cutting and pre-commercial thinning.Item Ecosystem pioneers: beaver dispersal and settlement site selection in the context of habitat restoration(Montana State University - Bozeman, College of Agriculture, 2018) Ritter, Torrey Daniel; Chairperson, Graduate Committee: Lance McNewThe activities of beavers (Castor canadensis) provide a variety of benefits to stream systems by capturing and storing water and sediment, expanding riparian areas, and increasing habitat heterogeneity. Understandably, land and wildlife managers are interested in using beavers as a habitat restoration tool. However, streams targeted for restoration are often degraded and lack recent beaver activity, and therefore represent suboptimal habitat. The habitat selection process for beavers in suboptimal and unmodified habitats provides a natural analogue to beaver restoration, but the process is not well-understood. I radio-marked juvenile beavers and conducted beaver-use surveys in tributary streams of the Gallatin and Madison River drainages in southwest Montana to investigate dispersal, survival, and settlement site selection by beavers colonizing novel areas. My objective was to study beaver ecology in the context of beaver restoration to improve identification of suitable project locations. Beaver colony densities in the study area were low or average, though colony densities in suitable habitat were generally high. There was evidence of delayed dispersal, and as the density of active beaver colonies increased the probability of dispersal decreased. Radio-marked beavers that dispersed settled quickly and dispersal distances were highly variable. Most beavers settled in active colonies or other beaver-modified habitats, and colonization of unmodified stream segments was rare. My top habitat selection models indicated new settlement sites were located in stream segments characterized by low gradients, dense woody riparian vegetation close to the stream, and relatively narrow stream channels. Stream channels at new settlement sites were more variable both in cross-sectional and longitudinal depth and were more heavily influenced by secondary channels than unsettled sites. My results suggest beavers select for pre-engineered habitat over unoccupied stream segments, and in novel areas habitat conditions that facilitate stable dam construction appear most important. When choosing project locations, restoration practitioners should consider local beaver colony locations and densities to assess the potential for dispersers to reach the restoration site. Stream segments that provide dam resiliency and hiding cover should be targeted for initial restoration efforts, and pre-engineering of habitat prior to beaver occupancy may increase the probability of successful colony establishment.Item Red squirrel (Tamiasciurus hudsonicus) midden site selection and the influence of conifer species compositions on midden occurrence in the Cooke City Basin of Montana(Montana State University - Bozeman, College of Agriculture, 2017) Elkins, Eric Kyle; Chairperson, Graduate Committee: Bok SowellThroughout the Greater Yellowstone Ecosystem (GYE), whitebark pine (WBP: Pinus albicaulis) seeds serve as an important fall food source for threatened Yellowstone grizzly bears (Ursus arctos). Grizzly bears depend on red squirrel (Tamiasciurus hudsonicus) midden sites to obtain WBP seeds. In light of recent WBP population declines, managers are concerned about the negative effects that loss of WBP may have on grizzly bears. Therefore, managing WBP for grizzly bears is facilitated by understanding red squirrel habitat requirements and identifying areas that are most likely to contain middens. Previous studies indicate that red squirrel middens are most prevalent in subalpine mixed conifer forests with interspersed WBP, but a critical gap remains in identifying a conifer species composition that is ideal for midden sites. We studied red squirrel habitat selection in the Cooke City Basin (CCB) of Montana to identify variables associated with midden sites and midden area. We also examined conifer species compositions to identify a composition where middens are most likely to occur. Habitat variables, midden counts, and midden area measurements were collected in 810, 30 meter diameter circular plots equally spaced along 27 transect lines in the CCB. General linear mixed models (GLMM) were used to assess variables associated with red squirrel midden site selection, and linear mixed models (LMM) were used to assess variables associated with midden area. Results of the GLMM indicated that red squirrel midden occurrence probability is positively associated with the amount of hillshade (light) and canopy cover in a conifer stand. Additionally, midden occurrence increased as the percent WBP in a stand increased up to 44 percent, but decreased thereafter. Results of the LMM indicated that midden area is positively associated with total canopy cover. We identified that a conifer species composition of approximately 44 percent WBP and a 56 percent mixture of subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmannii) is ideal for midden sites. We concluded that managing for areas within subalpine zone mixed conifer forests containing similar compositions should be a priority to ensure availability of prime habitat for midden sites and associated WBP seeds for grizzly bears.Item The influence of mine reclamation and highway reconstruction activities on grizzly bear habitat selection in the Cooke City basin, Montana(Montana State University - Bozeman, College of Agriculture, 2016) Rossi, Joao Luiz; Chairperson, Graduate Committee: Bok SowellThe grizzly bear (Ursus arctos) population of the Greater Yellowstone Ecosystem is increasing in numbers and expanding its range. In this scenario, the number of conflicts between humans and grizzly bears is likely to increase. Understanding how grizzly bear habitat selection is affected by concentrated high human use, such as construction projects, plays a major role in management decisions for this species. In this research, we combined bear sign data collected in 27 permanent transects during 11 years (1990-91, 1996-97, 2003-04, and 2007-11) with food habits analysis to provide a description of grizzly bear habitat use in 91km 2 of the Cooke City Basin, Montana. Data were collected during years of mine reclamation (2003-04), highway reconstruction (2007-09), and years when no major human activities occurred (1990-91, 1996-97, and 2010-11). The main objectives of this study were to quantify grizzly bear spatial avoidance to mine reclamation and highway reconstruction activities and provide knowledge about environmental factors influencing grizzly bear habitat in the Basin. Resource selection functions were used to address these goals. Results showed that, in the Cooke City Basin, grizzly bears selected for mid-high elevation, forested, south-west facing slopes (areas where whitebark pine seeds are most abundant) and avoided areas of high tertiary road density. Mine reclamation occurred near whitebark pine forests. The estimated grizzly bear use of areas within 1 km and 2 km of reclamation epicenters decreased 83% and 52%, respectively, in years of mine reclamation. Grizzly bears did not avoid areas beyond 2 km of mine reclamation or areas within 4 km of highway reconstruction in years when these activities occurred. The lack of avoidance associated with highway reconstruction is likely explained by the fact that this occurred in the lowest elevation areas (below 2500 m) that are used less by grizzly bears. Grizzly bears use in the Cooke City Basin were mostly uninterrupted by two major construction projects. However, temporary and localized habitat loss occurred when construction was focused near whitebark forests with high bear use. Temporary habitat loss was not observed when construction occurred in areas distant from whitebark forests and used less by bears.Item Habitat requirements of molting Canada geese at Lima Reservoir, Montana(Montana State University - Bozeman, College of Agriculture, 1979) Hildebrand, Bernard DeweyItem Predicting feeding site selection of mule deer on foothill and mountain rangelands(Montana State University - Bozeman, College of Agriculture, 2008) Bilbao, Joshua Vicente; Chairperson, Graduate Committee: Jeffrey C. Mosley.Determining areas on the landscape selected by mule deer (Odocoileus hemionus) for foraging and the characteristics of selected feeding sites is a crucial step in managing mule deer and its habitat. Mule deer populations in much of western North America have been declining since the early 1990's, making management of mule deer increasingly difficult. Limited research has examined the characteristics of mule deer habitat that influence feeding site selection in foothill and mountain rangeland habitats during the winter and spring. The purpose of the study was to develop and validate models that incorporate the effects of important habitat variables that influence feeding sites chosen by mule deer in the winter and spring, including aspect, distance to forested cover, distance to hiding cover, distance to agricultural fields, distance to improved roads, distance to ranch roads, elevation, previous cattle grazing, and slope. Data collected in northwestern Wyoming between the summer of 1999 and spring of 2001 were used for model development, and data collected between summer 2001 and spring 2003 were used for temporal validation. Additionally, data collected in west-central Montana between summer 2001 and spring 2003 were used for temporospatial validation. Logistic regression was used to develop models for the winter, spring, and winter-spring seasons. Akaike's Information Criterion was used to determine the best models for each season. Models were validated on both a temporal and temporospatial scale. Six habitat variables (distance to improved roads, distance to ranch roads, distance to security cover, aspect, slope, and previous summer's cattle grazing) were included in model development after collinearity tests. Four models had a model sensitivity > or equal to 75% in both temporal and temporospatial validation. These models can be used to identify preferred mule deer feeding sites and assess potential impacts of land management practices on mule deer foraging habitat.