In September 2024, the Lehigh Valley Zoo and Trexler Nature Preserve announced the passing of Big Boy, the patriarch of their bison herd. He was born at the Preserve and served as the leader of the herd for most of his life, fathering over a dozen offspring.
Five months after his passing, animal care staff have determined the need to intervene in the herd and split the group in half, due to a “shift in herd dynamics” as the males attempt to determine a new leader.
Bison are led by one bull who maintains group social structure and keeps the other males in a hierarchical structure. Animal care staff believe intervention and management is necessary to ensure the health and safety of each herd member. The group of fourteen will be split into two groups of seven and cared for in pastures on either side of the road.
Separating herd animals that are being cared for by humans is common. This often provides each animal with better care in cases of illness or injury. It also simplifies breeding. Most separations are done to ease tension between members who don’t get along.
Lehigh County has tasked the Lehigh Valley Zoo with caring for the Trexler Nature Preserve’s bison and elk for more than two decades. They hope to eventually return to one herd of bison. Plans are being made to move the current adult male bison and to bring in a new bull who can lead the full herd. This will require that new homes are found for the dispositioned bison in other zoo facilities, state or national parks, or preserves. Because of the LV Zoo’s accreditation by the Association of Zoos and Aquariums, they only plan to send the animals to approved locations.
Visitors are reminded that although the animals they’re viewing may seem docile, they are still wild animals. Guests should never reach through fences or attempt to feed the animals.
