An animal’s home-range can be expected to encompass the resources it requires for surviving or reproducing. Thus, animals inhabiting a heterogeneous landscape, where resource patches vary in size, shape and distribution, will naturally have home-ranges of varied sizes, so that each home-range encompasses a minimum required amount of a resource. Home-range size can be estimated from telemetry data, and often key resources, or proxies for them such as the areas of important habitat types, can be mapped. We propose a new method, Resource-Area-Dependence Analysis (RADA), which uses a sample of tracked animals and a categorical map to i) infer in which map categories important resources are accessible, ii) within which home range cores they are found, and iii) estimate the mean minimum areas of these map categories required for such resource provision. We provide three examples of applying RADA to datasets of radio-tracked animals from southern England: 15 red squirrels Sciurus vulgaris, 17 gray squirrels S. carolinensis and 114 common buzzards Buteo buteo. The analyses showed that each red squirrel required a mean (95% CL) of 0.48 ha (0.24-0.97) of pine wood within the outermost home-range, each gray squirrel needed 0.34 ha (0.11-1.12) ha of mature deciduous woodland and 0.035-0.046 ha of wheat, also within the outermost home-range, while each buzzard required 0.54 ha (0.35-0.82) of rough ground close to the home-range center and 14 ha (11-17) of meadow within an intermediate core, with 52% of them also relying on 0.41 ha (0.29-0.59) of suburban land near the home-range center. RADA thus provides a useful tool to infer key animal resource requirements during studies of animal movement and habitat use.
Kenward-et-al_RADA_Buzzard_radio-tracking_data
Data used to infer the resource needs of common buzzards (Buteo buteo) Dorset, southern UK. Inference was made by applying Resource-Area-Dependence Analysis (RADA) to a sample of 114 buzzard home ranges and a thematic map depicting resource distribution. The compressed archive contains the radio-tracking dataset, which consists of standardized 30 locations per home range obtained via VHF telemetry between 1990 and 1995. The thematic map, formed by using knowledge about buzzards to group 25 land-cover types of the Land Cover Map of Great Britain into 16 map classes, is available against permission at public site http://www.ceh.ac.uk/services/land-cover-map-1990. All coordinates are in UK National Grid format (EPSG 27700). The radio-tracking dataset is provided as: (i) .txt and (ii) .loc. The format in (ii) is native to the Ranges suite of software (http://www.anatrack.com/home.php) for the analysis of animal home ranging and habitat use. Since its first release in 1990, Ranges has been used in analyses underpinning dozens of publications in scientific journals (ex. http://www.anatrack.com/publications.php). The release of the latest version, Ranges 9, was used for RADA outputs in this paper. A DEMO of Ranges 9, which allows for opening and visualizing the data files provided herein, is available for download without charge (http://www.anatrack.com/try_ranges.php). RADA itself is available in the full Ranges 9 version (http://www.anatrack.com/ranges_compare_versions.php).
Kenward-et-al_RADA_Gray-squirrels_Elton
Data used to infer the resource needs of gray squirrels (Sciurus carolinensis) in Elton Estate, southern UK. Inference was made by applying Resource-Area-Dependence Analysis (RADA) to a sample of 17 gray squirrel home ranges and a thematic map depicting resource distribution. The compressed archive contains the two datasets: i) standardized 30 locations per home range obtained via VHF telemetry during July 1989 and 2) the thematic map containing six classes digitized from aerial photography. All coordinates are in UK National Grid format (EPSG 27700). Each dataset is provided as: (i) .txt (locations) and .shp (vector map) and (ii) .loc (locations) and .ves (vector map). Formats in (ii) are native to the Ranges suite of software (http://www.anatrack.com/home.php) for the analysis of animal home ranging and habitat use. Since its first release in 1990, Ranges has been used in analyses underpinning dozens of publications in scientific journals (ex. http://www.anatrack.com/publications.php). The release of the latest version, Ranges 9, was used for RADA outputs in this paper. A DEMO of Ranges 9, which allows for opening and visualizing the data files provided herein, is available for download without charge (http://www.anatrack.com/try_ranges.php). RADA itself is available in the full Ranges 9 version (http://www.anatrack.com/ranges_compare_versions.php).
Kenward-et-al_RADA_Red-squirrels_Furzey-Island
Data used to infer the resource needs of red squirrels (Sciurus vulgaris) in Furzey Island, southern UK. Inference was made by applying Resource-Area-Dependence Analysis (RADA) to a sample of 15 red squirrel home ranges and a thematic map depicting resource distribution. The compressed archive contains the two datasets: i) standardized 30 locations per home range obtained via VHF telemetry between October 1991 and January 1992 and 2) the thematic map containing two map classes digitized from aerial photography. All coordinates are in UK National Grid format (EPSG 27700). Each dataset is provided as: (i) .txt (locations) and .shp (vector map) and (ii) .loc (locations) and .ves (vector map). Formats in (ii) are native to the Ranges suite of software (http://www.anatrack.com/home.php) for the analysis of animal home ranging and habitat use. Since its first release in 1990, Ranges has been used in analyses underpinning dozens of publications in scientific journals (ex. http://www.anatrack.com/publications.php). The release of the latest version, Ranges 9, was used for RADA outputs in this paper. A DEMO of Ranges 9, which allows for opening and visualizing the data files provided herein, is available for download without charge (http://www.anatrack.com/try_ranges.php). RADA itself is available in the full Ranges 9 version (http://www.anatrack.com/ranges_compare_versions.php).