Hi Sal - I have used our standard Jacobs' index equation based on telemetry locations. It is important to account for available habitat at the appropriate scale - if you have telemetry data then you can use available habitat within each home range; if you are looking at incidental observations (definitely follow Christian's advice and use some kind of occupancy model), then you could look at all available habitat within the survey area. These two methods will provide information on habitat selection at different scales. If you have sufficient replicates, you can test for selection using t-tests or sign tests against a mean of 0 (i.e. no selection), as we have done with the large predator prey preference work.

Cheers

Matt

Hi again Salvador. Try to use MaxLike to model habitat selection

http://www.uvm.edu/~ngotelli/manuscriptpdfs/Fitzpatrick_et_al_2013.pdf

Jose

We were faced with a similar problem for bear (and the wolves in the same area), not only difficult, but expensive and taking years. We used incidental observations, corrected for observation bias and modeled the distribution with a set of fundamental environmental variables. Attached the article with the results. Please be welcome if you need more information.

Article Where the bears roam in Majella National Park, Italy

Hello, we are using models of ocupancy with the Software PRESENCE and are trying to generate further habitat association models using the frequency of sign (tracks, feces, and photos with camera traps) in the plant associations of the places where we work, is Northern Mexico. One approach we have taken in other works are the HSI (Habitat Suitability Index), part of the evaluator expertis and spatially explicit models are generated.

An apology for my bad English, greetings

Thanks all. How do you decide on the number of surveys or points to model Habitat selection. How many replicates/kms of survey for lets say 1000 sq km area.

Hi Sal - I have used our standard Jacobs' index equation based on telemetry locations. It is important to account for available habitat at the appropriate scale - if you have telemetry data then you can use available habitat within each home range; if you are looking at incidental observations (definitely follow Christian's advice and use some kind of occupancy model), then you could look at all available habitat within the survey area. These two methods will provide information on habitat selection at different scales. If you have sufficient replicates, you can test for selection using t-tests or sign tests against a mean of 0 (i.e. no selection), as we have done with the large predator prey preference work.

Cheers

Matt

Thanks Matt!

Hi Salvador

A 1000 sqkm is a very big area to study wildlife habitat selection. If you want to model all of it I would think you would have to sample, look for signs – tracks, pellets, carcasses, scratch marks etc, while walking at least a 1,000 km of wildlife trails. With each trail section walked once.

You should than study the decay rate of pellets and carcasses so that you could compensate for that.

Then you should build a habitat model – describing the area of study, using GIS and creating layers of elevation, slope, aspect, vegetation formation, human activity influence, agriculture, grazing activity and other parameters you think might influence wolves' habitat selection.

Then using usage-availability test you can see in which habitat patches you have signs more or less than expected by patch type and size.

I hope you have a good team of trackers to help you collect the signs information in the field 

Another possibility is to build the habitat model in the GIS at the beginning and than select sampling patches according to habitats availability, spreading a number and sizes of patches that you could sample over the course of time and effort you could put into the project. Than using usage-availability test you could examine which habitat categories within habitat parameters are significant for wolves habitat selection.

Hope this helps

Arik