Feds suspend aerial tranquilizing pending necropsy results
Wildlife biologists have temporarily suspended their Mexican gray wolf count and capture operation after two wolves died during the annual population survey.
As part of the wolf recovery effort, wildlife managers tranquilize the wolves from the air to attach radio collars, which gather biological information, such as dispersal, territories, habitat use, and breeding.
This year, two of the wolves died shortly after being tranquilized. The U.S. Fish and Wildlife Service will conduct necropsies at an Oregon lab to determine causes of death for each wolf.
According to the USFWS, the techniques, protocol, and drugs used were the same as those used throughout this year’s count and last year’s count. F1295 was darted and processed on January 23, released back into the wild and died four days later. F1340 was captured on January 28, and died within minutes of being darted. This year, 13 male and female wolves have been successfully darted, processed, collared and released back into the wild.
Prior to these 2 deaths, no wolves have died during past annual count and capture operations, which have been occurring since 2005 – successfully capturing and releasing 110 wolves to date. But there are several studies that examine the risks of wildlife tagging.
The handling and processing of the two wolves were led by personnel permitted by the Fish and Wildlife Service. These individuals received up-to-date training in drug immobilization and wolf handling. All personnel in the helicopter during the count and capture operations are current in training in helicopter safety and aerial capture techniques. A veterinarian was involved in the processing of both wolves.
“This team of biologists is dedicated to the recovery of these wolves and the last thing they want is to have a wolf die during these operations,” said Sherry Barrett, the U.S. Fish and Wildlife Service’s Mexican Wolf Recovery Coordinator. Barrett said the count and capture protocols coould be amended based on the results of the necropsies.
The annual population count and capture operation is conducted every winter to determine the minimum number of Mexican wolves in the Mexican Wolf Experimental Population Area. The wolves are counted by air via an airplane and helicopter. The captures are made with a tranquilizer dart from the helicopter.
“We understand the risks when conducting aerial capture operations, and our team takes extraordinary measures to reduce those risks. We continually conduct pre-operation and post-operation reviews to continue to improve our methods and procedures,” Barrett said.