Voices of the Future (11) - On Reintroduction of Species

by Shelby Harkless
Wildlife and Fisheries Science major, graduating Spring 2016

In terms of policy, there are very few set guidelines when it comes to the reintroduction of a species. There are a few guidelines from the Association of Zoos and Aquariums (AZA), but these only account for animals born or held in captivity, and they are not widely enforced. The IUCN does have guidelines on the reintroduction and translocation of species, but does not touch on specifically monitoring the stress of the individuals. Since the AZA and IUCN do not hold any legal power, it is essential to form laws ensuring reintroductions are performed as appropriately as possible, with minimal stress. This is a critical topic since it is believed we are entering the next great extinction. To slow, or counteract this process, we are able to take measures to reintroduce extinct or extirpated (absent from a specific area) species back into their native environments. Every species found on Earth has a specific niche within its ecosystem. Even the smallest organism can impact all other species found around it, from bacteria to wolves, with its absence.

Regulating reintroductions is near to my heart because it is the topic of my honors thesis. Sources to reference for your own personal gain will be cited numerically in parentheses, with their accompanying information listed at the end of this post. I am researching how the stress of an individual arctic ground squirrel affects their dispersal and survival rates after being introduced into an area in Kluane National Park, Yukon Territory, Canada where the species was previously extirpated (1). The squirrels were tracked using radio telemetry to determine survival and dispersal using GPS. The new environment was also altered in one of four different ways (tall grass no artificial burrows, tall grass with artificial burrows, short grass no artificial burrows, and short grass with artificial burrows) to determine if habitat type may determine the habitat use by the animals. In previous studies, it has been shown that increased stress, determined by measuring fecal glucocorticoids, will cause higher mortality and higher dispersion (2).

If studies such as mine can show that lower stress does in fact improve survival and lower dispersion, then it would be critical to ensure lower stress in future attempts. This can be accomplished by performing several different methods of reintroduction. For example, my experiment used soft release and hard release methods to compare how they affected the stress level of the individual. In the soft release, the squirrels were placed into holding cages for approximately two weeks to acclimate to the area. Inside the cages, the squirrels were protected from all predators, provided with fresh water and food, and also provided with shelter from the elements before being released into the new area. Once released, the animals were still able to enter the cages which were now open, and were also still protected by an electric fence for an additional two weeks. On other hand, the hard release squirrels were immediately released into the new area without any acclimation period or assistance.

This comparison will be beneficial to determine if acclimation to the area can affect the outcome of the reintroduction as a whole. If an elevated stress level does hinder the success of the reintroduction, then every measure which could possibly lower the level should be taken. Future studies should take this into account. Similar to my study, others should use a variety of methods to determine which will result with the least amount of stress on the animal. At first, this should be practiced with smaller, less endangered animals at first to improve the quality of the attempts. Once this has been perfected, it can be used with more vulnerable animals which cannot afford to be lost to poor practices.

Since reintroductions are performed at the collegiate, state, and even national level, a national policy mandating stress evaluation be conducted during a reintroduction should be established. This way, all parties involved would fall under the same guidelines. There are some rather simple ways to make this happen. You can simply talk to your state legislature to educate them about the issue and solution, or bring it up to the ecology/wildlife and fisheries departments of colleges and universities. I believe educating the source of the reintroduction itself is key to ensure people are willing to abide by the new practices. Laboratories which are able to perform the stress analysis need to cooperate with this new procedure in order to ensure its success. With your help, we can help improve the success of future reintroductions of our precious species.

1. Wheeler, Helen C., and David S. Hik. "Arctic Ground Squirrels Urocitellus Parryii as Drivers and Indicators of Change in Northern Ecosystems." Mammal Review 43.3 (2013): 238-55.
2. Sheriff, M. J., et al. "Mountain‐top and valley‐bottom Experiences: The Stress Axis as an Integrator of Environmental Variability in Arctic Ground Squirrel Populations." Journal of zoology 287.1 (2012): 65-75.

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Anonymous said…
God Bless you for your excellent work and dedication. Very well done.

I sincerely mean the above and don't know if my comment is appropriate at this time but I'm a senior "Senior" and some senility should be tolerated.

Just wondering if there have been any studies done on the "Reintroduction of the Family" ?

Been hearing a lot about less people getting married. Been hearing a lot about out of Wedlock kids. Its my understanding that Family is the basis of civilization and without a family structure, individuals have no restraints and return to animal habitat and life. Believe we have had some recent examples of this.


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