Theses and Dissertations at Montana State University (MSU)
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Item Space use and foraging patterns of the white-headed woodpecker in western Idaho(Montana State University - Bozeman, College of Letters & Science, 2017) Kehoe, Adam Roarke; Chairperson, Graduate Committee: Jay J. RotellaThe white-headed woodpecker (Picoides albolarvatus) is a species of conservation concern that is strongly associated with ponderosa pine (Pinus ponderosa)-dominated forests in the Inland Northwest. More information on home range size and habitat selection patterns is needed to inform conservation of the white-headed woodpecker, a focal management species for dry-forest restoration treatments. We examined whether home range size was associated with food resources and if fine-scale habitat characteristics influenced selection of foraging sites. During the post-fledging periods of 2014 and 2015, we radio-tracked 11 white-headed woodpeckers in forests of west-central Idaho. These forests were historically managed for timber harvest, resulting in removal of large-diameter, cone-producing ponderosa pine trees. We hypothesized that ponderosa pine cones would be a highly-valued food resource providing seeds and arthropods. We expected smaller home ranges to be associated with a greater availability of cones for foraging and that cone foraging would be concentrated in core use areas. We used foraging behavior to test this hypothesis, specifically, the proportion of time foraging on cones as an index of cone availability. Home range sizes ranged from 24 to 169 ha (90% fixed-kernel estimates). Consistent with our hypothesis, individuals with relatively small home ranges spent a greater proportion of foraging time on cones (Beta superscript 1 [SE] = 2.48[1.32], P = 0.096; Beta superscript 2 [SE] = -5.00[1.61], P = 0.014). Cone foraging was also higher in core use areas compared to home range peripheries for individuals exhibiting at least moderate cone foraging. We also expected foraging woodpeckers to favor larger diameter pines in sites with moderate to high canopy closure. To test this hypothesis, we analyzed foraging-site selection by comparing habitat characteristics between foraging trees and available trees, which provided support for our foraging site prediction (Beta superscript TREEDIAMETER [SE] = 3.50[0.43], P <0.001; Beta superscript CANOPY [SE] = 1.74[0.41], P <0.001; Beta superscript SPECIES [SE] = 1.43[0.33], P <0.001). Our results suggest that large diameter pines provide important foraging resources, and that landscapes with more productive cone crops could support greater numbers of white-headed woodpeckers. We recommend restoration treatments that retain high-density patches of large diameter pines while promoting mosaics of open and closed canopies at larger spatial scales.Item Demographic responses of woodpeckers in relation to a mountain pine beetle epidemic in the Elkhorn Mountains of Montana(Montana State University - Bozeman, College of Letters & Science, 2015) Dresser, Matthew Alan; Chairperson, Graduate Committee: Jay J. RotellaMountain pine beetle (Dendroctonus ponderosae; MPB) epidemics in coniferous forests of western North America have recently increased in size and severity, which affects wildlife habitat. Development of meaningful habitat-conservation strategies therefore requires information on wildlife population responses to mountain pine beetle. Over nine years (2003-2006, 2009-2013), we monitored 355 nests of 5 woodpecker species: American three-toed woodpecker (Picoides dorsalis), hairy woodpecker (P. villosus), downy woodpecker (P. pubescens), red-shafted northern flicker (Colaptes auratus cafer), and red-naped sapsucker (Sphyrapicus nuchalis) in the Elkhorn Mountains of Montana. In our study area, a MPB epidemic began in 2006 and peaked in 2008. We investigated the relationships between daily survival rate (DSR) and metrics of epidemic severity and timing (epidemic period, annual and cumulative estimates of tree-mortality, and red squirrel [Tamiasciurus hudsonicus] counts) while accounting for other potentially important covariates identified in previous studies (temperature, precipitation, time within the breeding season, nest height, diameter at breast height of the nest tree, and nest-tree species). Additionally, we examined trends in densities of hatched nests concurrent with the epidemic. In general, we found little support for a relationship between DSR and variables that described MPB epidemic timing and severity. Red-naped sapsucker was the only species to show a relationship between DSR and a MPB-related variable (cumulative tree-mortality). In contrast, densities of hatched nests for American three-toed, hairy, and downy woodpeckers increased following the epidemic, whereas, nest densities for red-naped sapsucker did not change. We found stronger support for nest survival relationships with covariates unrelated to the MPB epidemic (temperature, nest height, diameter at breast height of the cavity tree), but even these relationships were only weakly supported. As is commonly the case for cavity-nesting birds, nest survival was relatively high, leaving little room for covariate relationships. Our findings suggest that woodpecker populations tend to relate positively with MPB epidemics, although these relationships may often be the result of numerical increases in nest densities rather than functional increases in nest survival rates.Item Demography of Lewis's Woodpecker, breeding bird densities, and riparian aspen integrity in a grazed landscape(Montana State University - Bozeman, College of Letters & Science, 2005) Newlon, Karen Rachel; Chairperson, Graduate Committee: Jay J. RotellaAspen (Populus tremuloides) riparian woodlands are extremely limited in distribution throughout the western U.S., yet these habitats have a disproportionate value to breeding birds. Aspen habitats are also considered prime sheep and cattle summer range, particularly in the semiarid Intermountain West. Such concentrated use has raised concern about the effects of sheep and cattle grazing on these habitats. We examined the influences of sheep and cattle grazing on aspen riparian woodlands and the associated breeding bird community. We had two objectives: 1) to determine how habitats grazed by sheep and cattle influenced the reproductive biology of Lewis's Woodpecker (Melanerpes lewis), and 2) to determine how vegetation differed between sheep and cattle-grazed aspen riparian woodlands and how these differences influenced breeding birds densities. To examine what factors influenced nest-site selection in Lewis's Woodpecker and whether these factors influenced nest survival, we quantified nest-site characteristics and monitored nests to determine nest fate. Lewis's Woodpecker nest-site selection was positively influenced by nest tree diameter and tree density and negatively influenced by increasing amounts of bare ground and woody stems. However, these characteristics were not strong predictors of nest survival. Instead, nest initiation date and daily average temperature had the strongest influence. We then compared several vegetation characteristics between grazing treatments, conducted point transect surveys and used distance sampling techniques to estimate breeding bird densities. Cattle-grazed sites had more bare ground, less herbaceous cover, lower willow (Salix spp.) densities, and lower aspen densities than sheep-grazed sites. Differences in breeding bird densities between these grazing treatments reflected these vegetation differences, as ground-nesting species and riparian specialists had lower densities in cattle-grazed areas. Data from this study provide landowners and land managers with information on the habitat requirements of sensitive bird species needed to implement compatible grazing strategies in aspen riparian woodlands.Item Influence of postfire salvage logging on Black-backed woodpecker nest-site selection and nest survival(Montana State University - Bozeman, College of Letters & Science, 2009) Forristal, Christopher David; Chairperson, Graduate Committee: Jay J. Rotella; Vicki Saab (co-chair)Post-fire timber harvest practices (i.e. post-fire salvage logging) on public lands are a highly contentious issue in the western United States. Harvest of burned trees impacts a number of species, particularly those specialized for using post-wildfire habitats. We assessed the effects of post-fire salvage logging on black-backed woodpecker (Picoides arcticus) nest-site selection and nest survival within burned, mixed conifer forests of south-central Oregon. Multiple treatment and control plots were surveyed two years pre-logging (2003-04) and two years post-logging (2005-06). Our objectives were to (a) examine the effects of salvage logging on black-backed woodpecker nest site selection and nest survival at coarse and fine spatial scales (b) elucidate additional habitat and abiotic factors predicting black-back nest occurrence and survival, and (c) determine if those habitat covariates influencing nest site selection coincide with those influencing nest survival. A total of 210 black-backed woodpecker nests were monitored during the four year postfire period. Postfire salvage logging did not significantly reduce snag numbers or diameters within treatment units. Based upon our best nest-site selection model, black-backed woodpecker nest locations were different from non-nest points in habitat characteristics at both fine and coarse spatial scales, with variables related to surrounding snag density being the strongest predictors. Black-backed woodpeckers exhibited high overall nest survival (78.5%; 95% CL = 0.6996, 0.8495). Nest survival models containing temporal predictors (i.e. Julian date) received more support than those related to salvage harvest or other habitat features. Factors influencing black-backed woodpecker nest-site selection were not same as those affecting nest survival, suggesting a lack of adaptive nest-site choice in terms of nest survival. Our results correspond with past studies outlining the importance of high-density snag areas for woodpecker nesting. Maintaining complete snag species composition and high snag densities will help conserve black-backed woodpecker nesting habitat in the early years following stand-replacement wildfire.Item Nest-site selection and nest survival of two woodpecker species in ponderosa-pine dominated forests(Montana State University - Bozeman, College of Letters & Science, 2007) Story, Scott Joseph; Chairperson, Graduate Committee: Andrew J. Hansen; Victoria Saab (co-chair)Management of woodpecker populations requires knowledge of nesting habitat and vital rates in different forest conditions. We examined nest-site selection and nest survival for two woodpeckers, northern flicker (Colaptes auratus) and hairy woodpecker (Picoides villosus) at three locations in ponderosa-pine forests of the interior Columbia River Basin. Our goals were to: (1) characterize the range of habitat conditions available to nesting woodpeckers in our study area; (2) determine which habitat features best discriminated between nest and non-nest plots, and (3) establish which habitat features most influenced daily nest survival. Northern flickers and hairy woodpeckers were more likely to choose snags than live trees. Both species used larger diameter snags than those available at random. Nest snags tended to be in plots that had higher snag densities and lower live tree densities. For northern flickers, a model of constant daily survival received more support than any model containing habitat covariates.