Question

pets

Answer 1

These are good for measures of microhabitat. But assuming the species in quesiton has a larger 'home range' ~1km, you can easily quantify a bunch of variables in a 1km radius of the capture point using google maps and GIS. There's a lot of papers that do it. Measure area of variables such as grey space 'urban', blue space 'water' and green space 'vegetation'.

There are two main approaches in active contours based on the mathematic implementation: snakes and level sets. Snakes explicitly move predefined snake points based on an energy minimization scheme, while level set approaches movecontours implicitly as a particular level of a function.