counting
There is an "easy" way of estimating deer density in woodland but many factors are in involved in other habitats.
As defined by (Mayel, 1999) DCS in 2008 with the Best practice guide the equation is simply
N (est number of deer) = (number of pellet groups per m2 x 1000,000) divided by
................................. ----------------------------------------
..............................(number of days between visits * defecation rate)
Can it be applied in anything other than a woodland habitat? maybe however accuracy will be poor unless the following conditions are observed:
Decay rate is calculated for .A) habitat type and .B) time of year (decay rate is important to know as if you dont know it you may visit your survey site and find that some of the dung has decayed before you estimate the population. If this happens then population estimates will be less than accurate)
Daily defecation rate (may vary depending on species, available food source, microbiota present, soil type etc etc needs to be factored into your model).
And ultimatley training in surveying technique. if you define a pellet group as 6 o >6 and have no value as to the mass of faeces an individual produces in a single defication event, then it is very possible that you will count a single defication or pellet group as more than 1 which will really skew your estimation ..
For example a Roe deer is likely to produce less volume of fecal matter than a Red deer due to the size difference between these species.
Current estimates recommend counting only groups with 6 pellets or more (DCS,2008) as a "pellet group". If pellet groups are separated by distance (animal is defecating while moving) then it is possible that several pellet groups are left in the survey area by a single animal during a single defecation event. If a pellet group from a single defecation event is distributed over a distance it is likely that each part of this pellet group will be counted as having been produced by either a different individual or at a different time which will lead to inaccuracies in the final calculation of population estimation (a higher number of individuals in an area).
other than the above, there is open range counting, infra red surveying or just observation ... they are all simple methods realy.
Skipp