Nurturing a historic herd of bison

The bison herd at Trexler Nature Preserve owes Kelly Craig a debt of gratitude.

“I just wanted to know, why don’t we have any baby bison?” Craig said she often wondered during frequent visits to commune with the peaceful yet ferocious creatures.

She did a little research and learned the nine females — or cows — at the eastern Pennsylvania preserve were on birth control. The family planning practice prevented any bouncing baby bison surprises, but it also meant a vital link to Lehigh County’s heritage would eventually disappear.

In response to her inquiry, the county is developing a breeding program at the preserve, where fording Jordan Creek en route to the bison paddock is a favorite memory for Lehigh Valley natives.

This year also marks the 100th year — what Craig termed the “bisontennial” — since Gen. Harry C. Trexler, an avid game hunter, introduced bison to the property near the village of Schnecksville.

“We didn’t want to have the day come when there were no more bison at Trexler Nature Preserve, so we had to make a change,” County Executive Don Cunningham said. “We want a perpetual presence of the bison in Lehigh County.”

The scenic Trexler Nature Preserve, a 1,108-acre public park traversed by trails used for walking, hiking and biking, is a favorite spot for ornithologists, fishing enthusiasts and hunters.

The preserve is home to the Lehigh Valley Zoo, where an exhibit of three Mexican gray wolves opened in April; a few years ago the South African penguins were all the rage. The county contracts with the zoo for care and feeding of the bison, as well as elk and palomino horses.

Schnecksville, a suburb of Allentown, maintains its rural roots with a thriving century-old dairy farm. A country fair has been held in the community every summer for 30 years.

According to the Wildlands Conservancy, the Trexler bison have not enjoyed quite the same consistency.

In 1927 the herd grew so large that some bison were sent off to a park and two zoos. During the Great Depression, bison were the victims of poaching.

Tuberculosis hit the herd in 1955, and all 93 animals perished. Two years later, 25 bison were purchased to rebuild the herd.

On a recent morning, the bison snorted and huffed, hovering around their feeding corral. A few bolted through a chute used to keep them still for veterinarians, and thundered against the metal sides.

Around the time Trexler resettled the bison in his game preserve in North Whitehall and Lowhill townships, hunting had brought the species near extinction, with only about 1,000 of the beasts left in North America, according to the Wildlife Conservation Society.

“Hunters were the first conservationists,” said Rich Rosevear, general curator at Lehigh Valley Zoo. “They were out there seeing how fast the animals were disappearing.”

When Trexler died in 1933, there were 98 bison in the herd, making it the biggest east of the Mississippi River at that time, Rosevear said.

But breeding bison isn’t as easy as pouring the champagne and dimming the lights.

Taking the cows off contraception doesn’t guarantee they’ll be able to conceive, said Glenn Solt, the county general services director. As insurance, the zoo is looking for ranches and other zoos willing to part with two fertile cows.

Of the three bulls at the preserve, the dominant male will play papa, and the others will be traded. Zookeepers had been worried he’d soon have to fend off challenges by the two adolescent bulls anyway, Rosevear said. “Breeding behavior” didn’t stop when the females went on the pill in 2003, he said.

Now that the goal is procreation, the county is creating a 9.5-acre honeymoon suite of sorts across the road from the current 8.5-acre paddock, Parks Director Bob Stiffler said.

The herd will be rotated to take advantage of the new grasses. The paddock will be surrounded by a heavy-duty fence made for safety, not privacy — voyeurs will still have a clear view from the road.

Cue the romantic music.

jenna.portnoy@mcall.com