John. Thank you very much for the operative response to my question

Nikolay,

as John pointed already out, it is important to consider if the animals you want to assess have unique features that allows you to identify them individually. Most of the literature and methods available are dealing with more-or-less clearly identifiable species such as Felidae.

Foster and Harmsen published 2012 a critical review on the application of camera trap data (http://onlinelibrary.wiley.com/doi/10.1002/jwmg.275/full). Thereby, they pointed out that most difficulties in camera traps studies came from inadequate sample size, biased camera placement, etc. They also referred to techniques for assessing animals that cannot be recognized individually, such as the estimation method presented by Rowcliffe et al. in 2008 (http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2008.01473.x/full). As you mention the possibility to do video recording, the method of Rowcliffe et al. might give you additional chances, as it uses features such as animal speed, which might be tricky by simple photo captures.

Hope, this brings you further in your efforts.

http://onlinelibrary.wiley.com/doi/10.1002/jwmg.275/full

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2008.01473.x/full

Pascal, thank you very much for your help! 

Sincerely, Nikolay

As John said, you could use data with animal identification to make a Spatial Capture Recapture. If you can only identify a fraction of the population (or even without identification) you can use Spatial Mark Resight. In this book you can find a lot of examples and codes.

This is the Google Site:

https://sites.google.com/site/spatialcapturerecapture/

Nikolay,

as Pascal mentioned:

we used the method of rowcliffe et al 2008 with fototraps and videotraps. With videotraps you have better chances to get all animals of one group (e.g. wild boar) to estimate the mean group size.

However, you need the speed (distance traveld per 24h) of your species...

Oliver

An other source: An evaluation of camera traps for inventorying large- and medium-sized terrestrial rainforest mammals. Tobler er al. 2008. Animal Conservation 11(3): 169-178. ntl 10.1111/j.1469-1795.2008.00169.x

Nikolay,

I used camera traps to estimate bobcat density based on mark-recapture using individual coat patterns. I used known travel distances of the animals for camera station placement and trapping grid configuration.  Camera placement, height above ground, trigger speed, lens axis orientation, presence of travel corridors, trigger sensor volume, and such are all very important to consider when placing your stations. Ensure you adequetely explore these requirements to ensure you are not missing animals.

I captured many other mammals in the camera traps as well, including other carnivores and prey species. Many of which did not have characteristics that allow for mark-recapture. I created a relative index of abundance for these other mammals based on number of passes per 24 hours per species per station. If there were multiple passes of a species at a station in a 24 hour period, I only counted a single pass. For instance, a fox may have walked numerous times in front of the camera in a single night, triggering the camera multiple times. I only counted it as one pass for that 24 hour period. However, I created a separate data area called activity patterns (time when the animals were captured), so multiple pass data was not a total waste. Good luck and remain patient and persistent.

Cheers,

Charles

Colleagues, thank you very much for your help and advices! We desired transition from the indices of occurrence on the population density.

Nikolay

Colleagues, I recommend to get acquainted with the work of my colleagues Andrei and Elena Volkova. It offers an interesting index - the number of camera traps-day for one day of registration an animal.

Nikolay, it would be helpful to translate it into english. My russian is just rudimentary (half a year at school, about three decades ago)...

Oliver, good! We will translate.

Nikolay