As the largest carnivore in Iran, the brown bear has been less studied across its vast distribution in the country, composing of Zagros and Alborz Mountains. Central Alborz Protected Area has been hosting the longest ever conducted investigation on the species in the country since 2005 by the Iranian Cheetah Society (ICS) funded by DZCF. During this period, 13 different families of the bears were detected in the area which resulted an average litter size of 2. Comparing to other bear populations in the world, it is one of the smallest means for the bears which is speculated that low occurrence of meat in food items of the bears in the area explains this relatively small litter size. We hypothesize that the north-central portion of the Alborz Protected Area is a female core area which supports surrounding sink populations and needs to be protected more effectively. Results of the study has been published recently by the ICS experts in Ursus journal.
Moreover, intensive studies on the species in the Europe have shown that mother age can affect productivity in the brown bears, so older moms normally have more cubs. Therefore, litter size can serve as an indication for healthy status of the bear populations as in high-poaching areas; they are expected to have less number of cubs. The Iranian Cheetah Society (ICS) is now working on another research project through funds from Alertis Foundation in western Iran to explore more about it.
You can download the paper here.