Indexes are really only useful for monitoring trends over long time scales. For instance, one could do a coyote index by walking the same transects (ie. a road) and counting coyote scats or driving the same routes and howling and listening for two minutes afterwards for howl responses. This would be done year after year to produce a large data set that over time the trends of abundance could be teased out. The data is hard to utilize because you can’t really quantify the numbers, you wouldn’t know of all the scars are from the same coyote or from 20 different coyotes. To do it correctly you would need to replicate how your are collecting data, same roads, same howl recording, same time frame of listening for responses etc. A common index that is conducted annually is grouse drumming counts in the spring where someone would sit at the same location and listen for grouse drums for a predetermined amount of time and go to those same locations year after year. over the course of time one could say that there is 20% more drumming observed than in previous years but that is about all that it is useful for. Indexes are often used with other data gathering techniques like hunter collected grouse wings to determine an age structure from year to year. Utilizing multiple data collection techniques will build a better picture of the population. For furbearers, some index techniques are scat and track counts, muskrat hut or beaver lodge counts, even badger hole counts. These are often complimented by things like bobcat and otter check-ins where a genetic sample is taken and a tooth for aging. From the teeth they can get an age strucure (more younger critters indicates good reproduction) and genetics can now find a lot of things out about population numbers, migration etc. Some states even request carcasses to be turned in (pine marten is a good example) so they can look at the uterine scars to determine how many litters they have had. As the data set builds they can see long term trends that show good or poor reproduction in a species that people are concerned about. Trail camera bait stations are also utilized a lot any more, they can determine presence of a species, which habitats they prefer and some even are rigged where the bait is hanging off the ground so the critter has to stand up to eat and they can see the sex on the picture, and they rig some barbed wire to collect hair to get a genetic sample without having to have the critter in hand. That technique is used for wolverine monitoring in several western states. Probably more than you wanted to know but those are a few ideas. If the property that you want to index is small you probably won’t find much for useful information on a species that has a large range like a coyote though.
