Wolves, coyotes, and hybrids, oh my! And I'm not talking about werewolves.
Hybridization is the interbreeding of two different species making fertile offspring. It can
occur naturally in many plant, insect, fish, bird, and other organisms. It is thought to be
an important aspect of evolution. However, hybridization can also be a big cause of
endangerment to many species. (Fredrickson & Hedrick, 2005) If extensive,
hybridization can threaten the survival of any animal. (Hailer & Leonard, 2009) It can
lead to the extinction of one or both of the parental species when there are no genetically
pure individuals. (Fredrickson & Hedrick, 2005) Hybridization with coyotes continues to
threaten the recovery of endangered red wolves in the north. (Adams et al., 2006) Some
say it might be the greatest biological threat to them. (Fredrickson & Hedrick, 2005) The
question is: is there a way to locate and remove coyotes and hybrids so that the
endangered wolves can multiply and prosper?
Global warming isn't the only environmental threat that humans caused over the
years. The spread of farming has thought to facilitate coyote expansion. As humans
started industrializing and building new cities, coyotes and wolves started migrating. As
they migrated, their paths intersected causing the coyotes and wolves to mingle with each
other. As the different species hybridized, naturally the hybrids took characteristics from
both parents. For example coyotes originating in the Great Plains, moved eastward over
the past 90 years into a mix of forests and fields well suited for the deer and small prey
these animals thrive on. Northeastern coyotes are not just larger but they also have wolflike features. These coyotes have wider mouths, with bigger skulls where chewing
muscles attach, giving them a stronger bite for killing bigger prey. They eat more deer
and they are comfortable in forests, much like wolves. This has allowed the hybrid
coyotes to move more rapidly and capture deer, where as normal coyotes would eat
smaller animals (Kays et al., 2009). Hybridization is making these hybrid coyotes
stronger, quicker and larger but has sent the wolves straight to the endangered animals
list.
If reintroduced populations of wolves are to be self sufficient, it’s population size
must increase. If the population remains this small, the individual wolves will be unable
to find a wolf to mate with and may have to find a mate in a different species or may stop
breeding altogether (Hailer & Leonard, 2009). For species already threatened by
hybridization, increasing population numbers will not work if there is nothing preventing
hybridization in the future. In these cases, preventing or stopping contact between the
hybridizing species is the only course of action likely to prevent their loss. Sterilization
can also be an effective, but short-term way to lessen the likelihood of red wolf and
coyote interbreeding (Fredrickson & Hedrick, 2005). The key to preventing hybridization
in populations of endangered species is the detection and removal of hybrids. This can be
challenging for species that are wide-ranging and difficult to capture. Noninvasive
genetic sampling, by collecting faecal DNA (also known as poop), is a promising
alternative for locating hybrids within a population. Non-invasive techniques are
beneficial because individuals do not need to be captured and sampling can occur over a
large area. When this is combined with GIS technology (geographic information system)
exact locations of hybrids can be found, permitting an easier approach to hybrid removal.
This has been used to detect hybrids of endangered red wolves and coyotes (Adams et al,
2007).
Hybridization occurs all over the world in all organisms. In some cases, like those
of plants and in this case of the coyotes, hybridization can be a great factor of evolution.
In other cases, like those similar to the red wolves, hybridization can lead to
endangerment or even extinction. Efforts are being made to find ways for determining
when hybridization is becoming a problem and how to stop it from becoming extensive to
a point where it can become dangerous to one or both of the parental species. The
collection of faecies is a way to obtain DNA without having to capture any animals. It
also allows for a large range of sampling. This in addition to GIS technology will make
identifying hybrids more efficient. New ways of preventing any more hybridization is
still being researched and will continue to be researched until it is no longer a problem.