Readers of this blog will know that inbreeding in constricted wild animal populations is a threat to many species. Inbreeding has many negative results and can easily lead to local extinction. Now, University of California researchers are considering genetic rescue as a tool in the battle.
The focus of the genetic rescue effort is a very small population of red foxes in California. The montane red fox. The red fox (Vulpes vulpes linn) is common and may number over 1 million in the United States. The montane or Sierra Nevada red fox (Vulpes vulpes necator) is a different story. Their numbers may be under 50. Several other small pockets exist in California mountains.
According to UC scietists:
“Genomic research led by the University of California, Davis, reveals clues about montane red foxes’ distant past that may prove critical to their future survival. The study, published in the journal Molecular Biology and Evolution, examines the potential for genetic rescue to help restore populations of these mountain-dwelling red foxes. The research is especially relevant for the estimated 30 or fewer native red foxes living in the Lassen Peak region of California.
The study found that inbreeding is impacting the Lassen red fox population. Thousands of years ago — long before unregulated trapping and poison knocked back their populations in the 1890s and early 1900s — red foxes were not only abundant in these mountains, they were also more connected to neighboring foxes in Oregon, the Rocky Mountains and Washington Cascades than they are today. This positions them well for genetic rescue should managers decide to pursue it and reconnect the populations.”
Modern genetic advances make it possible to study changes in a population dating back thousands of years. UC researchers can then make recommendations about how and when to introduce foxes from different populations in order to re-invigorate the subject population. Although red foxes as a whole are abundant there are a number of isolated populations in California and increasing their diversity is a goal.
Other animals, including California mountain lions (Puma concolar) and Indian tigers (Panthera tigris) are also at risk for inbreeding and may need some form of genetic rescue.
Cougars in the Santa Monica Mountains are showing signs of inbreeding. Some of the obvious signs include kinked tails. Tigers in India and jaguars (Panthera onca) also show troubling signs. In all these cases genetic rescue may be attained by finding ways to bridge gaps between isolated populations. A freeway overcrossing above the 101 Freeway is being built. That should help bring isolated Santa Monica mountains cougars into contact with others. Similar efforts are taking place for jaguars in South America.
India is also looking at wildlife corridors to aid tigers.