The Wolf Conservation Center (WCC) participates in the Species Survival Plan (SSP) and Recovery Plan for two critically endangered wolf species, the Mexican gray wolf (Canis lupus baileyi) and the red wolf (Canis rufus). The Mexican gray wolf and the red wolf are among the rarest mammals in North America; both species at one time were completely extinct in the wild. An SSP is a breeding and management program designed to ensure the long-term sustainability of captive-based animal populations. The primary goal for the Mexican gray wolf SSP and red wolf SSP is to breed wolves for maximum genetic integrity for reintroduction into the wild. Organizations participating in the SSP are tasked with housing and caring for the wolves, collaborating in the captive breeding program, sharing observations and recommendations for release, and engaging in the sometimes unusual measures to save the species.

Because the entire existing populations of Mexican wolves and red wolves are derived from such a limited founding populations (just 7 individuals for the Mexican wolf and 14 for the red wolf), genetic health is the primary consideration governing decisions re: reproductive pairings and captive-to-wild release events. It’s also the reason that the SSP programs for both wolf species pursue an extraordinary conservation measure to save these species – gamete cryopreservation.

So last Friday WCC staff and volunteers set out to collect semen from 3 red wolves for potential future use. This is an important option when trying to maintain diversity with a species that was once extinct in the wild.

Our first task was to capture the 3 wolves. In order to do this, the WCC team herds the wolves through their spacious enclosures and into capture boxes – wooden doghouse-like structures with removable roofs. Once a wolf is contained in the box, we transfer the animal into a kennel in which we transport the wolves to the Center’s Freund Family Veterinary Facility.

Thankfully for the wolves, they won’t remember much beyond the capture. Semen collection from wolves requires anesthesia first, and then electro-ejaculation. Point Defiance Zoo & Aquarium’s Reproductive Biology Specialist, Ashley D. Franklin, Ph.D., led the procedure with the help of the WCC’s amazing volunteer veterinarian, North Westchester Veterinary Office‘s Paul Maus, DVM.

Ashley was able to determine how productive each wolf was by examining each deposit under the microscope to determine the number of sperm, the proportion of sperm moving and the quality of their movement, as well as the percentage of sperm with normal shape and an evaluation of the abnormal shapes present. Ashley then stored the samples in “pellets” to prepare for cryogenic preservation at the Point Defiance Zoo & Aquarium.

So here’s a breakdown of what the wolves produced:

• Red Wolf M1566: Weight – 49.2 lbs. Sperm present but many broken heads and tails.
• Red Wolf M1803: Weight – 74.8 lbs. Very productive collection – approximately 8.5 BILLION sperm. This was the most of the WCC males and possibly the biggest output from a wolf in Ashley’s career.
• Red Wolf M2075: Weight – 69lbs. Successful collection

Samples were frozen in pellet form in dry ice and then preserved in liquid nitrogen.

Enormous thanks to Point Defiance Zoo & Aquarium, Ashley Franklin, North Westchester Veterinary staff, Paul Maus, DVM, our family of awesome volunteers! But most of all, we owe our thanks to red wolves M1566, M1803, and M2075 for making a very personal and valuable contribution to the genetic health of their rare species!