Thesis (M.S.)--University of Tennessee, Knoxville, 2002. / Title from title page screen (viewed Feb. 26, 2003). Thesis advisor: Louis J. Gross. Document formatted into pages (vii, 82 p. : ill. (some col.)). Vita. Includes bibliographical references (p. 66-72).

O Cerrado é a maior, a mais rica e a mais ameaçada savana tropical do mundo, com aproximadamente 80% da sua vegetação nativa convertida em áreas modificadas, como pastagem e agricultura (Myers et al. 2000, Silva e Bates 2002, Klink e Machado 2005). É considerado um dos 25 hotspots mundiais para a conservação da biodiversidade devido à excepcional concentração de espécies endêmicas, alta riqueza de espécies e, também, por estar sofrendo uma rápida perda de vegetação nativa (Myers et al. 2000). Nele, foram registradas mais de 856 espécies de aves, das quais 4,3% são endêmicas (Cavalcanti 1999, Silva e Bates 2002, Marini e Garcia 2005, Silva e Santos 2005). O Cerrado abriga 78% das espécies de aves de campos naturais que ocorrem no Brasil, e 41% do total relacionado para a América do Sul (Vickery et al. 1999). Apesar dessa importância, grandes áreas de campos nativos foram modificadas pela expansão da agricultura mecanizada de larga escala no Cerrado (Cavalcanti 1999). O desaparecimento dos campos naturais tem causado um declínio alarmante nas populações de aves dependentes destes hábitats (Stotz et al. 1996, Cavalcanti 1999, Vickery et al.1999). A alta diversidade de aves e o considerável impacto humano demandam a priorização de pesquisas para subsidiar as ações conservacionistas no Cerrado (Cavalcanti 1999, Cavalcanti e Joly 2002, Macedo 2002). Entre elas está a geração de conhecimento sobre aspectos da história natural das espécies, informações consideradas essenciais para o desenvolvimento de medidas apropriadas para a conservação (Macedo 2002, Podulka et al. 2004, Sutherland et al. 2004, Lopes e Marini 2005). Numerosas espécies de aves que ocorrem no Cerrado ainda têm sua biologia pouco conhecida (Macedo 2002). Como exemplo têm-se Coryphaspiza melanotis e Cistothorus platensis, espécies habitantes de campos naturais no Cerrado (Tubelis e Cavalcanti 2001, Macedo 2002), esta última, inclusive, considerada espécie ameaçada de extinção (IUCN 2009). As informações disponíveis são, principalmente, de caráter geral, descritas brevemente em livros de ornitologia abrangentes, como guias de identificação de espécies (Ridgely e Tudor 1994, Stotz et al. 1996, Sick 1997, Sigrist 2006), ou em trabalhos sobre comunidades de espécies de aves (e.g. Tubelis e Cavalcanti 2001). Assim, publicações específicas e detalhadas sobre a biologia de C. melanotis e C. platensis são importantes para se compreender a biologia das espécies, assim como para disponibilizar informações importantes para estratégias de conservação e manejo (Pyke et al. 1977, Develey e Stouffer 2001, Lopes e Marini 2006). A presente pesquisa visa trazer informações pioneiras sobre a área de vida destas espécies de aves. Pesquisas sobre áreas de vida e territórios têm sido realizados em todos os continentes, principalmente com aves e mamíferos (Laver e Kelly 2008). Sherril e Case (1980) notaram que os termos área de vida e território costumam ser usados de maneira similar pela maioria dos autores, embora tenham sentidos diferentes. A área de vida é a área total na qual um indivíduo de uma espécie particular vive, buscando alimento, parceiros sexuais e abrigo (Pyke et al. 1977, Rose 1982). Por outro lado, o território é a porção da área de vida defendida contra outros indivíduos da mesma espécie (Odum e Kuenzler 1955, Podulka et al. 2004). Apesar de diversos aspectos dos estudos de áreas de vida e territórios já terem sido revisados (Schoener 1968, Worton 1987, Harris 1990, Lawson e Rodgers 1997, Powell 2000, Laver e Kelly 2008) nenhum estudo revisou publicações sobre aves de um determinado continente ou região biogeográfica. Além disso, nenhuma revisão abrangeu aspectos gerais das metodologias de estudos sobre áreas de vida e territórios de aves. Ao reunir informações de estudos de área de vida e territórios de aves realizados na região Neotropical, este trabalho pretende apontar lacunas de conhecimento e sugestões para pesquisas futuras. / In the Cerrado, native grasslands have been rapidly destroyed, leading to alarming declines in the populations of birds that rely on these habitats. Grassland species such as Coryphaspiza melanotis and Cistothorus platensis remain poorly known. The study of home ranges and territories of birds is important to understand their biology and for their conservation. The objective of this study was to study home ranges of C. melanotis and C. platensis at Parque Nacional da Chapada dos Veadeiros, central Brazil. Ten males of C. melanotis were studied between February and December 2008. The mean sizes of home ranges were 4.47 ± 1.49 ha (Minimum Convex Poligon) and 3.48 ± 1.44 ha (Kernel 95%) and varied between the studied seasons. The home ranges of all studied individuals were overlapped to those of at least three co-specifics. Small and highly overlapped home ranges can be considered a positive aspect for the conservation of C. melanotis. This is because grassland fragments and small reserves could contribute substantially for the conservation of populations through the Cerrado extension. Fourteen males of C. platensis were studied between February and December 2008. However, only five individuals were observed during all the study period. The mean sizes of their annual home ranges were 6.10 ± 2.09 ha (Minimum Convex Poligon) and 4.57 ± 1.92 ha (Kernel 95%) and varied between the seasons. These birds were quite territorial, holding territories similar to their home ranges and with low overlap with male neighbors. Our results highlight the existence of great differences between populations of C. platensis found in temperate and tropical regions. Other objective of this thesis was to review studies of home ranges and territories of birds conducted in the Neotropical region. A total of 130 scientific articles published between 1960 and 2011, with study areas in 23 countries, were revised. Home ranges were examined in 64% of the studies, while 36% of them studied territories. In 95% of the revised publications, information essential for the conduction of data collection and analyses is lacking, making impossible the replication of the studies. The study of home ranges and territories was not among the main results of numerous publications, that investigated other aspects of the biology of neotropical birds. Among the suggestions for future studies is a better description of the methodologies.

Island foxes (Urocyon littoralis) are currently listed as federally endangered on four of the six Channel Islands to which they are endemic. The Santa Rosa Island (SRI) population declined by 99% during the 1990’s due to non-native golden eagle (Aguila chrysaetos) predation and is currently the lowest fox population (~280) and density (0.86 foxes/km2) of any of the Channel Islands. The goals of this study were to assess new miniaturized GPS technology and to quantify home range and habitat use of the SRI population. This is only the second use of Global Positioning System (GPS) collars on Channel Island foxes and provides essential baseline data for the recovering population. These results can be used to guide management decisions and future habitat restoration efforts after the recent removal of non-native ungulates. In fall 2009, 14 GPS collars were deployed on male foxes on the east side of SRI. Nine collars and three remote download datasets were recovered in 2010. The collars’ battery life was 40% lower than expected at an average (±SE) of 16.5 ± 1.7 weeks but had high performance in precision and fix rate. Collars yielded an average of 347 ± 33 locations with a fix rate of 82.3% ± 2.1% and 88% of locations categorized as high precision. From these data, 95% minimum convex polygon (MCP) home ranges and 95% kernel density isopleth (KDI) home ranges were created. The average 95% MCP home range size was 3.39 ± 0.59km2 and the area of overlap with adjacent home ranges had a median of 5.3%. The average 95% KDI home range size was 3.82 ± 0.68km2 with a median overlap of 6.0%. These home range sizes are almost triple the size reported in other island fox studies, likely due to the low fox densities in the recovering SRI population. Habitat analysis was performed using KDI home ranges and a Euclidian distance analysis (EDA) method to assess habitat selection within the study area, the home range and the core area. Results showed selection for lupine within the study area, which no previous studies have documented. There was no significant habitat selection within the home ranges or core areas. Foxes selected for valley bottom topography and for bare and grassland habitat at night. One shortcoming of EDA is that its reliance on random points for determining second order selection can lead to unused areas being identified as selected habitat. The lack of significant selection within home ranges and core areas may be attributed to small sample sizes, use of male foxes only and the timing of the study in relation to fox reproductive biology. I recommend further investigation in the use of lupine habitat and associated resources through prey inventory studies to further assess these findings. When densities reach historic levels of 4 foxes/km2, follow up studies should be conducted to reassess home range size, overlap and habitat use to determine if home range sizes have decreased and overlap has increased. Future studies should incorporate spring and summer seasons and females to determine if foxes select a particular habitat within the core area during denning and pupping periods.

Parental care in animals can be costly and is shared between both parents in many bird species. Not surprisingly, most studies of how parental care is shared between the sexes are in sexually dimorphic species, and much less in known about sexually monomorphic species where sex cannot be determined in the field. This has prevented a full understanding of parental care behaviors – which are intrinsically linked to fitness – in species such as the Red-headed Woodpecker (Melanerpes erythrocephalus) that is experiencing population declines throughout much of its range. In this study we assessed whether Redheaded Woodpecker brooding time, nestling provisioning rates, and nest cleaning rates vary as a function of parent sex, habitat type (savanna and closed canopy forest), brood size, nestling age, temperature and/or date. We recorded and analyzed 128 hours of high-quality video from 21 broods at Fort A.P. Hill, Virginia where this species is relatively abundant. We captured and color-banded Red-headed Woodpeckers, taking breast feather samples for genetic sexing, and determined brood size and chick age of nests using an extendable pole camera. Using generalized linear mixed models, we found the best predictor of nestling provisioning was an interaction between chick age and date; older chicks were fed more frequently in early summer (before 7 July) compared to late summer. The seasonal reduction in provisioning could be related to a reduction in resource availability, but whether or not provisioning in later nests affects nestling survival warrants further study. We found chick age and parent sex to be the best predictors in brooding models, with females brooding more when chicks are less than 10 days old and males being the only parent to enter the cavity after 10 days. Additionally, males almost exclusively remove fecal sacs from nests, highlighting an observational method to determine sex of breeding adults in the field. Such division of reproductive roles is similar to what is known for dimorphic woodpecker species and likely indicates energetic constraints due to the need for high parental investment from both sexes. Parental care is inextricably linked with habitat quality and home range size. Parents will travel to obtain the resources necessary to provision their young, and larger home ranges during the demanding nestling provisioning stage may indicate increased effort resulting from fewer available resources near the nest. We estimated home range sizes of 25 breeding adult Red-headed Woodpeckers using PinPoint GPS tags and 95% kernel density estimates (KDEs) with plug-in smoothing factors. We modeled the effects of habitat, sex, nest stage, date, and distance to nearest neighbor on home range estimates. Red-headed Woodpecker males have larger home ranges than females, and late summer home ranges are smaller than those measured before 7 July. More study is needed to determine if sex or date is a stronger factor on home range, given our naive sampling which resulted in more females sampled in late summer and observations that did not continue to the end of the breeding season (late August). Since we found date to be an influential factor to both provisioning rate and home range size, it is possible that seasonal resource changes are an important, unstudied factor related to nationwide declines of this species.

Area used by male and female Phrynosoma mcallii (Hallowell) was studied in a population locted on the Barry M. Goldwater Aerial Gunnery Range near Yuma, Arizona. Area used by males and females shifted through time and did not fit the definition of home range. Summer male and female area used was not significantly different (F=2.625, df=1, P=0.131), but male areas used were significantly larger for 15-day time periods (F=9.67, P=0.0003). Males overlapped the area they occupied in consecutive 15-day time periods more often than did females. Female area used never overlapped within a 15-day time period. Male area used overlapped those of other males and females within a 15-day time period.

No description available.

Chronic wasting disease (CWD) has been a known threat to Saskatchewans wild cervid populations for more than a decade. As host movements can affect the spread of a disease across the landscape, disease models and management strategies should incorporate information regarding movement patterns of the host population in question. I used radio telemetry to study mule deer (<i>Odocoileus hemionus</i>) captured between 2006 and 2008 in a CWD-endemic region of southern Saskatchewan. Using location data from 152 individuals, I investigated home range size and patterns of direct and indirect contact (measured using proximity and shared space use) in relation to sex, habitat, and landscape structure. <p>Home ranges (95% fixed kernel) of GPS-collared deer in this study averaged 21.4 km² (n = 94). Male home ranges (mean = 29.5 km², n = 56) were larger than those of females (mean = 16.1 km², n = 38), which could have implications for CWD prevalence differences between sexes. Of the landscape variables tested, topographic ruggedness was inversely related to home range size and Shannons diversity (a measure of both habitat richness and evenness) was positively related to home range size. <p>Potential direct contact events were identified when two deer were located within 25 m of each other at the same point in time. These events occurred more often between February and April, agreeing with the tendency of mule deer to aggregate into large groups during the late winter months, and suggesting that this may be an important time period for disease transmission. Contact also occurred more than expected in cropland, whereas areas of shared use occurred more than expected in grassland, shrub/wood habitat, and rugged terrain. Smaller home ranges and greater degree of shared space use within areas of rough topography may lead to greater risk of environmental contamination with the infectious CWD agent in these areas. In contrast, the relationship between cropland and probability of direct contact may imply greater risk of direct CWD transmission between deer occupying this habitat. <p>These results identify connections between particular landscape factors and risk of CWD transmission and will be used, in combination with results of related studies, to develop a model of CWD spread in Saskatchewan. This will in turn aid management agencies in developing methods to more effectively manage the disease and control its movement outside of affected regions.

Wetland density is believed to be an important determinant of home range size variation in mallards (Anas platyrhynchos), but hypothesized effects of upland habitat and female size and age have not been adequately evaluated. Thus, I investigated correlates and consequences of home range size variation using radio-tracking data for 131 female mallards studied on 12 Canadian prairie parkland sites, 1995-1998. Home range size and habitat composition varied within and among study areas; overall, home range size variation was best modeled to include effects of seasonal and semi-permanent wetlands (β = -0.06 ± 0.01 SE) and wood-shrub habitat (β = -0.03 ± 0.01 SE). Contrary to predictions, I obtained no support for a positive association between home range size and female body size or a negative relationship between home range size and female age. After controlling effects of wetland density, mean home range sizes were larger on study areas with lower mallard breeding pair densities. I suspect that individual home ranges were smaller in areas of high pair density because of increased intraspecific competition for breeding space. A higher proportion of wood-shrub habitat may have contributed to smaller individual home range sizes because of greater relative availability of preferred nesting habitat. Likewise, a high proportion of wetlands in home ranges could enhance access to important resources such as food, leading to smaller home range sizes.<p> Reproductive and survival consequences were investigated using 8 variables to distinguish between three reproductive categories (females that either did not nest, nested but failed, or nested successfully) and two survival categories (dead versus alive) with discriminant function analysis. Successful females were clearly separated from non-nesting females by having smaller home ranges (95% kernel estimate) with higher percentages of wood-shrub and habitat treatment but lower percentages of seasonal and semi-permanent wetlands. Females that did not nest were further distinguished from nesting females by being younger, structurally smaller and having larger home ranges composed of higher percentages of seasonal and semi-permanent wetlands. Date of first nesting (standardized by study area) was not associated with home range composition. Survival was also unrelated to either home range composition or female attributes. Overall, breeding performance was better described by variation in landscape characteristics than by female attributes, a finding that is consistent with other recent evidence from breeding ducks.

Wetland density is believed to be an important determinant of home range size variation in mallards (Anas platyrhynchos), but hypothesized effects of upland habitat and female size and age have not been adequately evaluated. Thus, I investigated correlates and consequences of home range size variation using radio-tracking data for 131 female mallards studied on 12 Canadian prairie parkland sites, 1995-1998. Home range size and habitat composition varied within and among study areas; overall, home range size variation was best modeled to include effects of seasonal and semi-permanent wetlands (β = -0.06 ± 0.01 SE) and wood-shrub habitat (β = -0.03 ± 0.01 SE). Contrary to predictions, I obtained no support for a positive association between home range size and female body size or a negative relationship between home range size and female age. After controlling effects of wetland density, mean home range sizes were larger on study areas with lower mallard breeding pair densities. I suspect that individual home ranges were smaller in areas of high pair density because of increased intraspecific competition for breeding space. A higher proportion of wood-shrub habitat may have contributed to smaller individual home range sizes because of greater relative availability of preferred nesting habitat. Likewise, a high proportion of wetlands in home ranges could enhance access to important resources such as food, leading to smaller home range sizes.<p> Reproductive and survival consequences were investigated using 8 variables to distinguish between three reproductive categories (females that either did not nest, nested but failed, or nested successfully) and two survival categories (dead versus alive) with discriminant function analysis. Successful females were clearly separated from non-nesting females by having smaller home ranges (95% kernel estimate) with higher percentages of wood-shrub and habitat treatment but lower percentages of seasonal and semi-permanent wetlands. Females that did not nest were further distinguished from nesting females by being younger, structurally smaller and having larger home ranges composed of higher percentages of seasonal and semi-permanent wetlands. Date of first nesting (standardized by study area) was not associated with home range composition. Survival was also unrelated to either home range composition or female attributes. Overall, breeding performance was better described by variation in landscape characteristics than by female attributes, a finding that is consistent with other recent evidence from breeding ducks.

Chronic wasting disease (CWD) has been a known threat to Saskatchewans wild cervid populations for more than a decade. As host movements can affect the spread of a disease across the landscape, disease models and management strategies should incorporate information regarding movement patterns of the host population in question. I used radio telemetry to study mule deer (<i>Odocoileus hemionus</i>) captured between 2006 and 2008 in a CWD-endemic region of southern Saskatchewan. Using location data from 152 individuals, I investigated home range size and patterns of direct and indirect contact (measured using proximity and shared space use) in relation to sex, habitat, and landscape structure. <p>Home ranges (95% fixed kernel) of GPS-collared deer in this study averaged 21.4 km² (n = 94). Male home ranges (mean = 29.5 km², n = 56) were larger than those of females (mean = 16.1 km², n = 38), which could have implications for CWD prevalence differences between sexes. Of the landscape variables tested, topographic ruggedness was inversely related to home range size and Shannons diversity (a measure of both habitat richness and evenness) was positively related to home range size. <p>Potential direct contact events were identified when two deer were located within 25 m of each other at the same point in time. These events occurred more often between February and April, agreeing with the tendency of mule deer to aggregate into large groups during the late winter months, and suggesting that this may be an important time period for disease transmission. Contact also occurred more than expected in cropland, whereas areas of shared use occurred more than expected in grassland, shrub/wood habitat, and rugged terrain. Smaller home ranges and greater degree of shared space use within areas of rough topography may lead to greater risk of environmental contamination with the infectious CWD agent in these areas. In contrast, the relationship between cropland and probability of direct contact may imply greater risk of direct CWD transmission between deer occupying this habitat. <p>These results identify connections between particular landscape factors and risk of CWD transmission and will be used, in combination with results of related studies, to develop a model of CWD spread in Saskatchewan. This will in turn aid management agencies in developing methods to more effectively manage the disease and control its movement outside of affected regions.