Annual counts of endangered Mexican gray wolves in New Mexico and Arizona began in 2005. The counts provide an update on the species' recovery in the Southwest, while also giving biologists a chance to collect valuable information on certain animals that are temporarily captured. Biologists fit those animals with tracking collars, draw blood samples and measure them, all of which aid research and management of the population.
Being able to track the canids is key to figuring out appropriate areas for future releases of captive wolves into the wild because those new additions can’t be put into territory already claimed by another pack, said Sherry Barrett, Mexican wolf recovery coordinator for the U.S. Fish and Wildlife Service.
The successful release into the wild of adults raised in captivity is fundamental to maintaining the diversity of the Mexican gray wolf population and preventing detrimental impacts of inbreeding, Barrett said. If animals that are too closely related begin mating, it can result in outcomes like birth defects or smaller litter sizes, she said.
GPS tracking collars being put on the wolves also provide data for a long term study on the rate of wild ungulate and livestock killings by wolves. In the study, biologists analyze wolf location information transmitted by the collars several times per day. If two or more data points show up in one place, it could indicate that was the site of a kill because multiple wolves were at that spot, said Julia Smith, a biologist with the Arizona Game and Fish Department. If they do suspect that was the case, biologists go out to those locations to confirm if the wolves did make a kill.
The project aims to gather solid data on the number of wild ungulates and livestock taken down by the wolves, giving federal and state agencies solid information about the predators’ impact on those animals and informing policy decisions about Mexican gray wolf management in the future, Smith said. So far, neither New Mexico nor Arizona have been able to record that wolves have had an impact on wild ungulate populations, said Jeff Humphrey, spokesman for the U.S. Fish and Wildlife Service.
Blood samples collected from the animals are used to scan for diseases and for genetics tracking. Some samples also are sent to the University of New Mexico’s Museum of Southwestern Biology for use on future projects and research, said Susan Dicks, a staff veterinarian and biologist with the U.S. Fish and Wildlife Service.
Teeth measurements help wildlife managers identify whether a wolf was responsible for an ungulate killing while paw measurements are useful in answering questions about tracks left in the sand or snow, Dicks said. Knowing the body size and weight of the animals is useful for tracking trends in the population over time, she said.
While the information collected from the wolves is certainly useful, biologists have to find a balance between the need and desire to gather data from the animal and the time crunch to get it back into the wild, Barrett said.
“When you’re doing research like this and taking measurements, there is always that tradeoff between how much time you want to hold an animal down and get measurements versus getting the information that you may need or want in the future,” she said.