scholarly journals Sex Differences in Space Use of Breeding Common Ravens in Western Marin County, California

The Condor ◽  
2004 ◽  
Vol 106 (3) ◽  
pp. 529-539 ◽  
Author(s):  
Jennifer E. Roth ◽  
John P. Kelly ◽  
William J. Sydeman ◽  
Mark A. Colwell

Abstract We estimated core areas and home-range sizes and evaluated sex differences in home-range size, seasonal variation in movements, and space use for breeding Common Ravens (Corvus corax) in western Marin County, California. There were no significant interannual differences in average core area or average home-range size for either sex, although there were small-scale shifts in home-range use for 67% of females and 63% of males. There was no significant difference in home-range size between the sexes. Home-range size was positively correlated with distance to food source. Ravens traveled shorter distances from the nest during the incubation + nestling stage compared to other stages of the breeding season. Core areas were centered around nest sites and food sources, with significantly aggregated locations for 83% and 100% of females in 2000 and 2001, respectively. Males were more variable in their use of space, with significantly aggregated locations for 38% and 44% of males in 2000 and 2001, respectively. Individual variation in home-range size, movements, and space use was likely due to differences in the distribution of important food sources in the area. Diferencias Sexuales en la Utilización del Espacio en Corvus corax en el Oeste del Condado Marin, California Resumen. Estimamos los tamaños del área núcleo y rango de hogar y evaluamos las diferencias entre sexos en el tamaño del rango de hogar, variaciones estacionales de los movimientos y utilización del espacio en Corvus corax en el oeste del condado Marin, California. No hubo diferencias interanuales significativas en el área núcleo promedio ni en el rango de hogar promedio para ninguno de los sexos, aunque para el 67% de las hembras y el 63% de los machos hubo cambios de pequeña escala en el uso del rango de hogar. No hubo diferencias significativas en el tamaño de los rangos de hogar entre sexos. El tamaño del rango de hogar estuvo positivamente correlacionado con la distancia a la fuente de alimento. Los cuervos viajaron distancias más cortas desde el nido durante los períodos de incubación y de cría de polluelos en comparación con otros períodos durante la época reproductiva. Las áreas núcleo se centraron en los sitios de nidificación y las fuentes de alimento, con posiciones significativamente agregadas para el 83% y 100% de las hembras en 2000 y 2001, respectivamente. Los machos presentaron mayor variabilidad en la utilización del espacio, con posiciones significativamente agregadas para un 38% y 44% de los machos en el 2000 y 2001, respectivamente. Las variaciones individuales en el tamaño de los ámbitos de hogar, movimientos y uso del espacio fueron probablemente dadas por las diferencias en la distribución de los recursos alimenticios importantes en el área.

2012 ◽  
Vol 90 (3) ◽  
pp. 337-344 ◽  
Author(s):  
Amariah A. Lebsock ◽  
Christopher L. Burdett ◽  
Safi K. Darden ◽  
Torben Dabelsteen ◽  
Michael F. Antolin ◽  
...  

Space use is a fundamental characteristic that informs our knowledge of social relationships and the degree to which individuals are territorial. Until recently, relatively little was known about the spatial ecology and social organization of swift foxes ( Vulpes velox (Say, 1823)). We investigated space use of swift foxes on shortgrass prairie in northeastern Colorado. Our first objective was to evaluate sizes of seasonal and annual home ranges and core areas of 13 radio-collared swift foxes monitored continuously for 2 years. Our second objective was to compare home-range and core-area overlap of breeding pairs to that of neighboring foxes, including male–male, female–female, and nonbreeding female–male dyads. Home-range size in our study population was among the smallest previously reported for swift foxes. Males tended to have slightly larger home ranges and core areas than females, and home-range size was significantly larger in the breeding season than in both the pup-rearing and the dispersal seasons; sizes of core areas did not differ seasonally. Spatial overlap between breeding pairs was substantial, whereas spatial overlap between neighbors, particularly males, was low, suggesting territoriality.


2005 ◽  
Vol 83 (11) ◽  
pp. 1431-1437 ◽  
Author(s):  
Christian Dussault ◽  
Réhaume Courtois ◽  
Jean-Pierre Ouellet ◽  
Irène Girard

We assessed the influence of temporal and spatial changes in food availability on home-range size and movements of moose (Alces alces (L., 1758)). Ten adult moose were radio-collared and monitored with GPS telemetry collars during two contrasting time periods based on food quality and availability: summer (growing period) and winter (dormant and snowy period). According to the habitat productivity – home-range size hypothesis, we expected home-range size and movement rate to be negatively correlated with the proportion of food-rich habitat types in home ranges. Food availability influenced space use, but the effect was more pronounced at the small scale (i.e., movement rates) than at the large scale (i.e., home-range sizes) and during winter than summer. The negative relationship between food availability and home-range size only existed in winter, but movement rates were lower in food-rich habitat types in both time periods. Our results suggested that body size was not the primary factor governing sex-related differences in space use which were likely more related to specific needs of females with regard to the feeding and protection of calves. We suggest that the habitat productivity – home-range size hypothesis may not always be supported when forage is widely distributed and that movement rates can be a better index of forage availability than home-range sizes in such situations.


2011 ◽  
Vol 77 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Silvia S. Costa ◽  
Rui Andrade ◽  
Luis A. Carneiro ◽  
Emanuel J. Gonçalves ◽  
Kurt Kotrschal ◽  
...  

2012 ◽  
Vol 62 (4) ◽  
pp. 381-396 ◽  
Author(s):  
Florencia Bonatto ◽  
Daniela Gomez ◽  
Andrea Steinmann ◽  
José Priotto

Patterns of space use and sexual dimorphism are frequently used to infer mating systems. We examined body size and home range size and intra- and intersexual overlap degree in order to elucidate mating strategy of Akodon azarae males. We studied spacing patterns using 113 and 129 home ranges established by males and females, respectively, in four 0.25 ha enclosures during the breeding season. Significant differences between sexes in home range size and overlap degree were found. Male home ranges were always larger than those of females. We observed exclusive space use among males and among females. Considering only those males that shared their home ranges with females, average intersexual overlap value was about 50%. Males mainly overlap their home ranges with home ranges of two or three females. Significant differences in body size were found between males and females, with males being larger. We concluded that space use and sexual dimorphism in this species is consistent with patterns characteristic of polygynous rodents, and we propose a polygynous system in A. azarae.


Animals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 275 ◽  
Author(s):  
Julie Young ◽  
Julie Golla ◽  
John Draper ◽  
Derek Broman ◽  
Terry Blankenship ◽  
...  

Global urbanization is rapidly changing the landscape for wildlife species that must learn to persist in declining wild spacing, adapt, or risk extinction. Many mesopredators have successfully exploited urban niches, and research on these species in an urban setting offers insights into the traits that facilitate their success. In this study, we examined space use and activity patterns from GPS-collared bobcats (Lynx rufus) in the Dallas–Fort Worth metroplex, Texas, USA. We found that bobcats select for natural/agricultural features, creeks, and water ways and there is greater home-range overlap in these habitats. They avoid roads and are less likely to have home-range overlap in habitats with more roads. Home-range size is relatively small and overlap relatively high, with older animals showing both greater home-range size and overlap. Simultaneous locations suggest bobcats are neither avoiding nor attracted to one another, despite the high overlap across home ranges. Finally, bobcats are active at all times of day and night. These results suggest that access to natural features and behavioral plasticity may enable bobcats to live in highly developed landscapes.


2008 ◽  
Vol 122 (1) ◽  
pp. 61 ◽  
Author(s):  
Matthew Schuler ◽  
Richard P. Thiel

Most studies of home ranges occur over short time periods and may not represent the spacial requirements of long-lived organisms such as turtles. Home ranges of 18 individual Blanding’s Turtles (Emydoidea blandingii) were measured using minimum convex polygons. Annual space use was compared to multi-year space use by individual turtles. We found a significant difference between annual home range size (25.5 hectares) and multi-year (two to six years) home range size (65.7 hectares; n = 18, P = 0.016). Caution should be employed when making management decisions based on short-term studies of long lived species.


2014 ◽  
Vol 60 (5) ◽  
pp. 616-621
Author(s):  
Tsewang Namgail ◽  
John Y. Takekawa ◽  
Sivananinthaperumal Bala-Chandran ◽  
Ponnusamy Sathiyaselvam ◽  
Taej Mundkur ◽  
...  

Abstract Relationship between species’ home range and their other biological traits remains poorly understood, especially in migratory birds due to the difficulty associated with tracking them. Advances in satellite telemetry and remote sensing techniques have proved instrumental in overcoming such challenges. We studied the space use of migratory ducks through satellite telemetry with an objective of understanding the influence of body mass and feeding habits on their home-range sizes. We marked 26 individuals, representing five species of migratory ducks, with satellite transmitters during two consecutive winters in three Indian states. We used kernel methods to estimate home ranges and core use areas of these waterfowl, and assessed the influence of body mass and feeding habits on home-range size. Feeding habits influenced the home-range size of the migratory ducks. Carnivorous ducks had the largest home ranges, herbivorous ducks the smallest, while omnivorous species had intermediate home-ranges. Body mass did not explain variation in home-range size. To our knowledge, this is the first study of its kind on migratory ducks, and it has important implications for their conservation and management.


Author(s):  
Ivan V. Seryodkin ◽  
Yuriy K. Kostyria ◽  
John M. Goodrich ◽  
Yuriy K. Petrunenko

Proper management of brown bear populations (Ursus arctos) requires knowledge of their ecology, including space use. Brown bear spatial patterns are particularly poorly understood in the Russian Far East, due to lack of telemetry studies. The aim of this work was to study space use by brown bears in the Sikhote-Alin region. From 1993 to 2002, we used VHF radiocollars to collect spatial data from nine males (eight adults and one juvenile) and six females (five adults and one juvenile) in the Middle Sikhote-Alin. Fixed Kernel home range size estimates were larger for males (891.34 ± 346.99 km2) than for females (349.94 ± 543.06 km2). The juvenile home range sizes were 237.24 and 333.64 km2 for the male and female, respectively. The maximum home range size was for the two-year area of one male (9217.36 km2). The core area sizes varied over a wide range (6.12–358.45 km2). The structure and location of home ranges and their core areas depended upon the seasonal habitat selection of bears, as well as the distribution, abundance, and accessibility of foraging resources. Bears’ home ranges overlapped between males and females, as well as between same sex individuals. The results of this work are important for the management of the brown bear population in the Sikhote-Alin


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