Fig 1.
Wolf pack territory map before and after displacement.
95% minimum convex polygons of the home ranges of the Wapiti Lake pack and the Mollie’s pack prior (2014–2016) to the displacement of the Wapiti Lake breeding male 755M (left) and post (2016 to present) displacement (right) in Yellowstone National Park. Proximity of the two packs’ territories likely contributed to the displacement of breeding male 755M, as described in this writing. However, wolf packs in Yellowstone National Park frequently have territories that abut or even overlap significantly. As breeding displacement has been fairly rare, it is unlikely that territory proximity explains the trigger for this event, rather it contributed to the ease of contact between packs.
Fig 2.
Notable wolves involved in the displacement.
Notable wolves involved in the displacement of Wapiti Lake breeding male 755M by males from the Mollie’s pack in the summer of 2016. Note the age differences between the males from the Mollie’s pack and 755M. Adult wolves were individually-identifiable. Graphics by Kira Cassidy.
Fig 3.
Coefficients of relatedness for genetically sampled wolves involved in the displacement of Wapiti Lake dominant male 755M in Yellowstone National Park.
Cell colors range from white (relatedness value of 0, indicating a pair is completely unrelated) to red (highest relatedness value of 0.5669, belonging to the sibling pair of 1014M and 1015M). Relatedness of approximately 0.5 is indicative of either full sibling or parent/offspring relationships. The uncollared black male from the Mollie’s pack was later captured and assigned the number 1155M. The gray female yearling was also later captured and assigned the number 1091F. The Yellowstone Wolf Project has not genetically sampled the Wapiti Lake dominant breeding female, so her parents’ (712M and 1093F) coefficients of relatedness are included here. See vonHoldt et al. 2020 for genotyping methods used to estimate relatedness [27].
Table 1.
Weight of notable male wolves.
Table 2.
Aggressive encounters between 755M and the intruding male from the Mollie’s pack.
Fig 4.
Gray wolf packs in the Greater Yellowstone Ecosystem with breeding individuals descended from the Wapiti Lake pack after the displacement of dominant male 755M in the summer of 2016. As of 2021, at least four packs in the ecosystem had dominant breeding individuals that were descended from one of the Wapiti Lake females and one of the Mollie’s males. Pups produced post-displacement are listed in parenthesis below pack names. These numbers are cumulative pups from five years of reproductive effort (2017–2021).