Presentation Details
Do gray wolves mate for life? Patterns in pair bonds from Canis lupus in Yellowstone National Park, WY

Kira A Cassidy, Douglas W Smith.

Yellowstone Center for Resources, National Park Service, Yellowstone National Park, WY, USA


Gray wolf (Canis lupus) packs are generally led by a dominant male-female pair, which are often the parents of the rest of the wolves in the pack (Mech and Boitani 2003). Pair bonds are an important aspect of sociality yet the details of divorce rates and impacts on the rest of the group are rarely studied (Clutton-Brock 2016). Using observations in Yellowstone National Park, Wyoming from 1995 through 2019 we recorded 152 distinct dominant pairs in 44 packs. Pair bonds usually terminated when one or both leaders died (76.4%) or when one leader switched to a subordinate role in the pack (14.2%). Pairs rarely divorced (9.4%). Vacancies in a leadership position were generally filled quickly. Unless the remaining leader died, it nearly always re-paired with a new partner whose origin (from within pack or from an unrelated pack) differed between males and females. In addition, the loss of either leader sometimes had negative consequences for the remaining leader or the entire pack. This suggests that the loss of a leader can be a period of instability for the pack and that the establishment of a new leading pair is important to pack success.