He concluded that the project failed because the number of fledged whooper chicks that survived to breeding age was not adequate.  And, among those that did survive, they showed little interest in pairing with their own species. His hypothesis was that they had imprinted on the sandhills that raised them rather than on their own species.  No one had tried cross-fostering before and  he did not know if imprinting issues would cause a problem.

Rod’s blood pressure would soar when talked about how he could not reduce the mortality of the chicks that did make it to fledging.  I’ll never forget his photo of a recently fledged dead whooper chick that had become entangled in one of the many Refuge barbed wire fences on one of it’s first flights.  That incindent led to removal of a many miles of Refuge barbed wire fences in the pastures  and modifications of their grazing system.     Rod was always emphatic that grazing on the NWR, which many conservationists opposed, was essential to substitute for bison grazing.  Cranes need large amounts of short grass habitat in the marsh system for foraging and evolved with large grazers.  Flipping over cow pies to eat the insects beneath is also an important food source of protein.

But Rod could not overcome the vulnerability of cranes to collisions with wires, be they powerlines or fences. Some apparently learn to avoid them, many die in their first collision.

I contacted Rod’s long-term project assistant Wendy Brown who is now retired from USFWS and asked her if there were any data regarding eagles killing whooping cranes.

Her reply:

.