Monday, January 28, 2013

Hunting effort and game vulnerability studies


Hunting effort and game vulnerability studies on a small scale: a new technique combining radio-telemetry, GPS and GIS

For centuries hunting has existed as a popular pastime (for both recreation and subsistence purposes) around the world. Yet, this practice affects the distribution, population, and behavior of game animals in many different areas. With respects to game management, it is important to understand the ways in which various harvesting strategies impact animal populations. Thus, it is important to have techniques that enable provide spatial data pertaining to both hunters and hunted populations. Recent technological advancements allow for the unique combination of GPS and GIS data in order to study special and temporal relations between hunters and game animals.

In this particular study, Brøseth and Pedersen combine GPS data from ptarmigan hunters in Norway with data from radio-tagged willow ptarmigan to identify factors affecting the bird's probability of survival in within an area of 30 square km. Hunts were conducted by 9 experiences hunters from the tenth through the twenty-second of September in 1997. GPS units were attached to the hunter's backpacks, tracking their movement throughout the hunting grounds. Each hunter marked the positions of harvested ptarmigans throughout each hunt. Those conducting the study captured ptarmigan within the hunting area during March and April prior to the hunts. They fitted the birds with necklace radio transmitters, which revealed valuable information about the birds and their habits (home ranges, etc.).





























*The image on the left depicts the lines taken by the hunters during this study, while the image on the right displays polygons revealing the home range of ptarmigans within the hunting area paired with lines used by hunters within these given ranges. It should also be noted that the circle indicates the lodge housing the hunters during this study.
            
During the 50 hunter-days hunters traveled a total of 818 km and harvested 135 birds (roughly 20% of the population). Logistic regression indicated that the birds that resided closer to the cabin experience higher hunting pressures and lower rates of survival (and vice versa). Although these results might seem obvious, the methods utilized in obtaining and analyzing data are fascinating to say the least. The combination of GIS, GPS and radio telemetry provides detailed visual information, which can greatly assist hunting and conservation efforts on a global scale.

Source:

Brøseth, H., & Pedersen, H. r. (2000). Hunting effort and game vulnerability studies on a small scale: a new technique combining radio-telemetry, GPS and GIS. Journal Of Applied Ecology, 37(1), 182-190. doi:10.1046/j.1365-2664.2000.00477.x

1 comment:

  1. I personally thought that ptarmigans that lived closest to the cabins would be safer. Most hunters usually go out from their cabins a decent distance before they start hunting. It is advanced to use the combination of GIS, GPS, and radio in order to do a study like this. Usually, they just use one of the technologies and track simpler questions. Using all three of these technologies would be useful in many studies besides hunting as well.

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