Academic literature on the topic 'Foxes – Habitat'

Decline of red fox (Vulpes vulpes) populations in Illinois has been attributed to altered geographic landscapes and the eastward expansion of the coyote. To investigate effects of habitat use and competition with coyotes on diets of foxes in intensively farmed landscapes of Illinois, we analyzed carbon and nitrogen isotope ratios (δ13C and δ15N) of foxes, coyotes (Canis latrans), and other local species. Foxes were categorized as rural (agricultural habitat, coyotes present), urban (urban habitat, coyotes absent), or from an agricultural research facility at the University of Illinois (South Farms, agricultural habitat, coyotes absent). Rural foxes had higher fur isotopic values (δ13C and δ15N) than rural coyotes, indicating that coyotes caused foxes to consume prey items from higher trophic levels and eat more C4 plants. Urban foxes had lower isotopic values (δ13C and δ15N) than South Farms foxes, suggesting that habitat use partly determined fox diets; foxes in urbanized habitats consumed prey at lower trophic levels within a largely C3 plant based food web. Models of competitive exclusion by coyotes were better predictors of fox long-term diets, including pup rearing, while habitat use models predicted fox diets on a narrower timescale. Competitive exclusion by coyotes might be an important factor explaining the decline of foxes in the intense farming areas of Illinois.

Many studies determine which habitat components are important to animals and the extent their use may overlap with competitive species. However, such studies are often undertaken after populations are in decline or under interspecific stress. Since habitat selection is not independent of interspecific stress, quantifying an animal's current landscape use could be misleading if the species distribution is suboptimal. We present an alternative approach by modeling the predicted distributions of two sympatric species on the landscape using dietary preferences and prey distribution. We compared the observed habitat use of kit foxes (Vulpes macrotis) and coyotes (Canis latrans) against their predicted distribution. Data included locations of kit foxes and coyotes, carnivore scat transects, and seasonal prey surveys. Although habitats demonstrated heterogeneity with respect to prey resources, only coyotes showed habitat use designed to maximize access to prey. In contrast, kit foxes used habitats which did not align closely with prey resources. Instead, habitat use by kit foxes represented spatial and behavioral strategies designed to minimize spatial overlap with coyotes while maximizing access to resources. Data on the distribution of prey, their dietary importance, and the species-specific disparities between predicted and observed habitat distributions supports a mechanism by which kit fox distribution is derived from intense competitive interactions with coyotes.

AbstractThere is a lack of information regarding the ecology and behaviour of red foxes that can be used to elaborate effective management programs for this species on Prince Edward Island (Canada). The main goal of this study was to provide baseline information on habitat selection and home range size of red foxes on Prince Edward Island. Data were collected from snow-tracking and radio-telemetry sessions conducted in two study sites (including one site within Prince Edward Island National Park). Our results indicated that red foxes selected for roads and human-use areas during both the breeding and the kit-rearing seasons in the park. Outside the park, however, the data failed to conclusively show that foxes have a unique preference for human-use habitats or roads. Forests were selected against in both study sites. Although roads are frequently visited by foxes during the kit-rearing season in the park, each individual fox typically stays in this habitat only for short periods of time (< 15 min). This finding suggests that foraging efficiency along the roads is very high possibly reflecting the abundance of anthropogenic food sources. Overall, we present the largest amount of data on habitat selection ever collected for red foxes in Prince Edward Island, Canada. Our results show that food sources in human-use areas and roads are altering the selection and/or use of habitats of red foxes in some areas of Prince Edward Island.

Habitat use by red fox (Vulpes vulpes) was studied during the winters of 1982 and 1983. A total of 125 km of fox trails in eastern Maine were followed during periods of snow cover to examine the influence of snow conditions on fox habitat selection and prey availability. Red foxes used all available habitats but showed preferences for softwood stands and open areas. Hardwood forests were avoided. During both winters, snow depth was greatest in hardwood and mixed stands where soft, powdery conditions prevailed. Windblown, supportive crusts were found in open barrens. Foxes showed habitat preferences for traveling and hunting. Fox sinking depths were least in all habitats when crust conditions prevailed, and during these periods travel distances were more evenly distributed among habitats. Snow influenced relative prey availability. Hunting activities shifted among habitats for small mammals during most of the second winter, when snow was shallow. Proportions of small mammals in the fox diet decreased as snow accumulated and as crusts formed. When snow was deep, foxes hunted in habitats with softwood regeneration and other dense understories that supported snowshoe hare concentrations.

Context. Extensive clearing and modification of habitat is likely to change many facets of the environment including climate and regional food resources. Such changes may result in changes in behaviour in highly mobile fauna, such as flying foxes. Aims.The availability of fruit resources was examined to determine whether grey-headed flying foxes (Pteropus poliocephalus) have feeding preferences related to habitat or dietary items, and whether human usage of the land around the colony site has affected the resources available. Methods. Fruit availability around a colony was monitored from December 2004 to March 2005. Night surveys and faecal analyses were undertaken to determine the distribution of feeding locations, the food species used and the food items consumed by P. poliocephalus. Key results.The amount of food available per hectare in each habitat was similar. However, we found differences in the composition of food trees and the distribution of food resources within each habitat. Ficus species were a major resource with flying foxes observed feeding in figs during every survey and figs identified in droppings over the whole period. Human-modified habitats were used throughout the study period with flying foxes observed in small patches of vegetation and in individual trees without any nearby vegetation. Conclusions. The need for maintaining vegetation, particularly Ficus species, in all areas where flying foxes are found, especially in human-modified habitats and rainforest remnants, is highlighted as this vegetation is of great importance to flying foxes. Other wildlife, such as birds and possums, may also benefit from the maintenance of this vegetation. Implications. Through management of urban resources there is the potential to prevent future conflict situations arising between humans and wildlife, such as can be seen when flying fox colonies are in close proximity to houses.

An understanding of the population dynamics and habitat of wild Red Foxes (Vulpes vulpes) and Coyotes (Canis latrans) is a prerequisite to wildlife management. This information is also important in assessing the risk these wild canids pose to the public and domestic animals. On Prince Edward Island, information on age, sex, reproductive activity, and habitat use of 271 Red Foxes and 201 Coyotes was collected in the hunting and trapping season of 2004–2005. The estimated age of Red Foxes and Coyotes ranged from 0.5 to 13.5 years. A large proportion of harvested Red Foxes and Coyotes (58% and 48%, respectively) consisted of juveniles. The sex ratio was not significantly different from 1:1 for either species. Average litter size was 5.0 and 5.2 for Red Foxes and Coyotes, respectively. Number of placental scars ranged from 0 to 7 in Red Foxes and from 0 to 11 in Coyotes. Agricultural areas were the main habitat type (52%) of harvested Red Foxes. For harvested Coyotes, forest was the main habitat (44%), followed closely by agricultural areas (43%). Urban areas were a significant part (13%) of the habitat of Red Foxes. These data can be used to monitor population dynamics over time, provide information for wildlife management, and provide information on potential risk areas for disease transmission by wild canids.

Habitat loss and alteration are two of the biggest threats facing insular flying-foxes. Altered habitats are often re-vegetated with introduced or domestic plant species on which flying-foxes may forage. However, these alien food plants may not meet the nutritional requirements of flying-foxes. The critically endangered Christmas Island flying-fox (CIFF; Pteropus natalis) is subject to habitat alteration and the introduction of alien food plants, and therefore is a good model species to evaluate the potential impact of alien plant species on insular flying-foxes. In this study, we evaluated nutritional content of native food plants to determine how flying-foxes historically met their nutritional requirements. Furthermore, we compared the nutritional content of native and alien fruits to predict possible impacts of alien plants on insular flying-foxes. Native and alien fruits and flowers, and native foliage (leaves, petals, and petioles) commonly consumed by the CIFF were collected and evaluated for soluble sugars, crude protein, non-fiber carbohydrates, and nine minerals. Evaluation of native food plants suggests that flying-foxes meet energy requirements by consuming fruit and nectar. However, fruit and nectar are low in protein and essential minerals required for demanding life periods; therefore, flying-foxes likely supplement their diets with pollen and foliage. Thus, flying-foxes require a diverse array of plants to meet their nutritional requirements. Compared to native fruits, alien fruits contained significantly higher non-fiber carbohydrates, and this may provide an important energy source, particularly from species that bear fruit year-round. Median mineral concentrations in alien fruit species, however, were deficient compared to native fruits, suggesting major (or even seasonal) shifts in the proportion of alien species in the CIFF diet could lead to nutritional imbalances. This study confirms the need to quantify nutritional parameters in addition to feeding ecology when evaluating habitat quality to inform conservation actions that can be applied both locally and globally.

Between 2000 and 2002 the home range, habitat selection and diet of foxes were examined in the Dandenong Creek Valley, Melbourne, Australia. The mean home range was 44.6 ha (range 19.2–152.6 ha). A significant selection towards blackberry and gorse used as diurnal shelter was found during the day with an active avoidance of less structurally complex vegetation types. Although there was obvious selection of certain habitats, the diet of the foxes was highly general and opportunistic and thus offers little potential as a factor to manipulate in order to reduce fox abundance. Given the strong preference for blackberry and gorse as a shelter resource, a habitat-manipulation strategy is suggested whereby patches of blackberry and gorse are removed and replaced with less structurally complex vegetation. Such a strategy has the potential to influence the density of foxes in semi-urban riparian environments such as those discussed in this study.

The activity patterns, home-range use, and habitat utilization of sympatric South American grey fox (Dusicyon griseus) and culpeo fox (Dusicyon culpaeus) in eastern Torres del Paine National Park, Chile, were studied to determine how the two species were distributed. Both species were primarily nocturnal. Mean percent daily activity did not differ between species or among seasons, but the grey fox had a greater daily activity rate in summer and fall and the culpeo fox in winter and spring. Seasonal and annual home ranges of culpeo foxes were larger than those of grey foxes, but did not differ between sexes or among seasons. Home ranges of grey and culpeo foxes were interspersed in a mosaic-like arrangement and did not overlap. Grey foxes were located more often in upland shrub transition habitat and in areas of medium cover density. Culpeo foxes were found more often in thickets of trees and in areas of high cover density. Within their home range, matorral shrubland or Nothofagus thicket habitat was selected by all culpeo foxes and by 60% of grey foxes monitored. Interference competition by the culpeo fox may have been important in determining fox distribution.

Abstract The Sacramento Valley red fox Vulpes vulpes patwin of California is a newly named subspecies recently found to be distinct both from other native red foxes and nearby introduced populations. The Sacramento Valley red fox experienced a historical demographic bottleneck resulting in a critically small genetic effective population size, causing concern over its current status and management requirements, yet little is known about its contemporary abundance, demographic trajectory, or habitat use. The hot, arid Sacramento Valley contrasts starkly in climate and physiography with the boreal habitats of other indigenous red foxes in western North America, indicating the need to obtain information specifically on the habitat requirements of this subspecies. A 3-y effort to locate reproductive den sites throughout the Sacramento Valley resulted in 42 independent dens, which we used to obtain preliminary information on habitat use and to develop a distribution model for this subspecies, and 28 Sacramento Valley red foxes killed by vehicles, which we used as independent data to test the models. Foxes were present significantly more than expected in grasslands and less than expected in wetlands and flooded agriculture and also tended to occur in proximity to human development, potentially as refuges from coyotes Canis latrans. We used Maxent to build predictive models. The best model, which incorporated vegetation/land-use classes and proximity to human development, identified 24% of the study area as predicted-presence habitat, which contained 76% of the den sites used to construct the model and 89% of independent locations used to test the model. Our model greatly narrowed the area over which foxes are predicted to occur and will facilitate future surveys to assess occupancy and ultimately abundance and population trends.

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.

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Estuaries are highly productive environments susceptible to environmental variables, and important to the life cycle of various species, to waterfowl serve as a point of rest, feeding and nesting. These sites also receive migratory birds seeking the accumulation of energy required for the return to the reproductive areas. These species, as well as residents, have their distribution, occurrence, abundance and behavior influenced by environmental variables, seasonality and human presence. Thus this study aimed to characterize the structure of the community of waterfowl, as well as behavioral pattern, relationship with environmental variables and habitat use by them in the mouths of the rivers Tijucas and Inferninho. The Tijucas’ Bay where this study was conducted, presents sediment deposition and formation of extensive muddy plans. To collect the data length of 1.1 km was covered in each mouth, from June 2015 to May 2016, sampling occurred every two hours, from 08 hours to 16 hours. The data collected were species, average number, activity and micro-habitat. five microhabitats were considered, based on different faces found in two locations, and analyzed environmental variables were: wind speed, tide height, precipitation and temperature. The curve of rarefaction and Jackknife 2 were used to determine the sample sufficiency, Shannon index was used to estimate the annual and monthly diversity and similarity among the studied areas was calculated using the Jaccard index. Analysis of Variance (ANOVA) and Kruskal-Wallis test were used to determine the differences between species richness, average number and behavior of the species for hours and months of sampling. The behavior relative frequency was grouped by similarity of Bray-Curtis, the Indicator Species Analysis was used to determine the association of species with micro-habitats, and used Canonical Correlation Analysis (CCA) to determine the correlation between the variables environmental and behavior and between species. Were recorded 44 species of waterfowl in the voices of the two rivers, 10 migratory. The similarity between the two areas was 75%, indicating high similarity of microhabitats between areas. The diversity at the mouth of the river Tijucas was higher than the mouth of the river Inferninho, this difference is related to river discharge of rivers, hence the nutrient input. The difference in species richness, abundance was significant only between the months of observation, and the months with the highest diversity occurred in the late spring, summer and early fall, probably due to the life cycle and arrival of migratory species. The rest was the most frequent activity, followed by foraging, this was negatively related to temperature variation, it suggests that the higher the temperature, the lower the foraging, avoiding waste of energy and water. Foraging was negatively correlated with the height of the tide as the low tide provides a food resource. The indicator species analysis showed that most of the species was associated with only one micro-habitats, this can be explained by the abundance of available resource, since rich environments allow specialization of species.
Os estuários são ambientes de elevada produtividade, suscetíveis a variáveis ambientais, e importantes para o ciclo de vida de diversas espécies, para as aves aquáticas servem como ponto de descanso, alimentação e nidificação. Esses locais ainda recebem aves migratórias que buscam o acúmulo de energia necessário para o regresso às áreas reprodutivas. Essas espécies, assim como as residentes, têm suas distribuição, ocorrência, abundância e comportamento influenciados pelas variáveis ambientais, sazonalidade e presença humana. Dessa forma esse estudo teve o objetivo de caracterizar a estrutura da comunidade de aves aquáticas, bem como padrão comportamental, relação com variáveis ambientais e uso de hábitat pelas mesmas nas fozes dos rios Tijucas e Inferninho. A Baía de Tijucas, onde esse trabalho foi realizado, apresenta deposição de sedimento e formação de extensos planos lamosos. Para coletar os dados a extensão de 1,1 km foi percorrida em cada foz, de junho de 2015 a maio de 2016, as amostragens ocorreram a cada duas horas, das 08 horas às 16 horas. Os dados coletados foram: espécie, número médio, atividade realizada e micro-habitat ocupado. Foram considerados cinco micro-hábitats, baseado nas diferentes fisionomias encontradas nos dois locais, e as variáveis ambientais analisadas foram: velocidade do vento, altura da maré, precipitação e temperatura. A curva de rarefação e Jackknife 2 foram usados para determinara a suficiência amostral, o índice de Shannon foi usado para estimar a diversidade anual e mensal, e a similaridade entre as áreas estudadas foi calculado através do índice de Jaccard. Análise de Variância (ANOVA) e teste de Kruskal-Wallis foram usados para determinar as diferenças entre riqueza, número médio e comportamento das espécies por horário e meses de amostragem. A frequência relativa de comportamentos foi agrupada pela similaridade de Bray-Curtis, a Análise de Espécie foi usada para determinar a associação das espécies com os micro-habitats, e usou-se Análise de Correlação Canônica (CCA) para determinar a correlação entre as variáveis ambientais e comportamentos e entre espécies. Foram registradas 44 espécies de aves aquáticas nas fozes dos dois rios, sendo 10 migratórias. A similaridade entre as duas áreas foi de 75%, indicando alta semelhança de micro-habitats entre as mesmas. A diversidade na foz do rio Tijucas foi maior que a foz do rio Inferninho, essa diferença está relacionada a descarga fluvial dos rios, consequentemente ao aporte de nutrientes. A diferença de riqueza, abundancia foi significativa apenas entre os meses de observação, e os meses com maiores diversidades ocorreram no final da primavera, verão e começo do outono, provavelmente devido ao ciclo de vida e chegada das espécies migratórias. O descanso foi a atividade mais frequente, seguido de forrageio, este esteve negativamente relacionada a variação de temperatura, sugere que quanto maior a temperatura, menor o forrageio, evitando dispêndio de energia e água. O forrageio esteve negativamente relacionado com a altura da maré, já que a maré baixa disponibiliza recurso alimentar. A análise de espécies indicadoras apontou que a maior parte das espécies esteve associada a apenas um micro-habitat, isso pode ser explicado pela abundância de recurso disponível, já que ambientes ricos permitem a especialização das espécies.