sentences:  Not all of sanctuaries are managed by experienced zoo professionals and staff, being able to deal with a variety of animals with different needs and requirements.Also the keeping conditions sometimes do not meet highest standards and in a number of instances the enclosures reach rather soon their carrying capacity, because it is usually very difficult if not impossible to release the animals into the wild (and also difficult to find suitable and appropriate places in zoos), making it impossible to further accept more animals.This may give rise to unjustified critique towards zoos in general in particular by some animal rights groups, which object to the keeping of wild animals (and for that matter also of domestic animals and companion animals in human care).