Publishing their work in the Journal of Animal Ecology, American researchers studied the ecology of the wolf in Yellowstone Park and established that the weight of the she-wolf and the size of the pack are decisive parameters in obtaining viable litters of cubs.
Using data collected over 14 years of field studies, Bridgett von Holdt of Princeton University and Dan Stahler, a biologist at Yellowstone Park, have carried out a genetic and ethological analysis of more than 300 grey wolves in this Wyoming national park, where the species was reintroduced in the 1990s. They assessed the animals’ reproductive success and survival rates, as well as the factors that influence them.
The weight, age and coat colour (grey or black) of the mother, the size of the pack and the size of the overall wolf population were all assessed. But some showed a greater impact than others. « Each of these factors affects reproduction, but overwhelmingly the body weight of the mother and the size of the pack are the main drivers of litter size and pup survival« , said Dan Stahler, lead author of the study, quoted by Science Daily.
« Large females produce larger litters, and large packs are better equipped to hunt and defend cubs and [food] resources against competing [packs] », explains Stahler. « A female’s body weight is the key to the survival of her offspring, and cooperation [between individuals] for the protection and feeding of cubs [also] bears fruit« , confirms Robert Wayne. confirms Robert Wayne, co-author of the study.
Artificial intelligence translation of an original text by MaxiSciences
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