Capturing elk with a net gun is not without negative impacts, said Ken Kingdon, Parks Canada project co-ordinator for the RMNP wildlife health program.
Tranquilizer darts are not used, because if the elk or deer leave the park and are later shot and eaten by hunters, drug residues in the meat may be harmful. Also, because the sedative effect may last for several hours afterwards, the animals may injure themselves, drown or fall victim to predators before it wears off.
The capture specialists first locate the animal from a helicopter, chase it into an open area, then swoop in alongside the running animal and fire the net over its antlers from a distance of about 10 feet. Its feet become tangled in the net, and it stumbles. With large bulls with huge antlers, broken necks may sometimes result.
The animal is wide awake the whole time, but it’s no different from being chased by wolves, said CFIA vet Dr. Bob Keffen.
They then quickly hobble its feet, blindfold it, take blood samples, put on a radio collar, and then release it – all in a matter of 10 to 15 minutes – with the aim of reducing capture trauma and stress.
Capturing wild animals without tranquilizers has a risk of inducing “capture myelopathy,” wherein the animal’s body releases a storm of stress hormones and acids that may kill the animal.
“In the acute phase, it may die right away on you, or two days later. In the chronic phase, three or four weeks after,” said Keffen.