Non-native species can be harmful to resident critters' health

Refuge Notebook

Posted: Friday, May 28, 2004

The recent discovery of crawfish in a local stream stirred quite a reaction from concerned citizens. It exposed how easily threats can occur to the fish and wildlife that populate our watersheds. The crawfish story follows a disturbing pattern along with the illegal introduction of yellow perch and northern pike into local waters. The threat of such exotic fish to anadromous and resident fish species is well known and often discussed among fishers.

The crawfish story brings to mind an often-overlooked problem that is very prevalent in Alaska and specifically on the Kenai Peninsula. Much of the attention on invasive species focuses on fish, plants, and insects, but invasive bird species are rarely seen as a threat to wildlife in our area. Only rock doves (pigeons) and European starlings are listed as invasive species by various state and federal agencies.

Though pigeons and starlings do pose significant threats, there are many other introduced bird species on the Kenai that pose a risk to native birds, other wildlife and even humans. Since the Kenai National Wildlife Refuge initiated the rare bird hotline in February, I have received numerous reports of birds that are not native to our area and in some cases not even native to North America. I recently had a pair of chukar land in my yard briefly and then fly off. There have also been sightings of turkey, California quail, ring-necked pheasant, bobwhite and various ducks and geese.

I would like to believe that these birds have simply escaped from their pens and their release was a total accident. Unfortunately, it is more likely a case of well-meaning people buying and releasing the birds in an attempt to have them breeding in the wild. What is baffling to me is that we jump at the first sight of crawfish, yet we don't even bat an eye when an introduced bird walks across our yard. We still allow groups to purposefully introduce game birds into the local environment with little regard for possible problems that may arise down the road.

The introduction of starlings into North America started with around 100 birds released in Central Park in New York City in 1890 and 1891. Europeans had recently settled in the New World and wanted to establish all of the birds mentioned by Shakespeare to bring a little flavor of home with them. This is not too dissimilar from people originating in the Midwest bringing a few yellow perch with them or Oregonians wanting a few chukar running around in their backyard.

There are conservative estimates that the starling population has reached over 200 million birds since that initial release approximately 100 years ago. These birds out-compete native birds for food and nest sites. Large flocks can devastate food crops grown for livestock and do considerable damage to fruit crops grown for human consumption. They also are vectors or hosts for a multitude of diseases.

At least 50 different human and livestock viruses and diseases have been documented in the droppings of rock dove and starlings in North America.

The list of viral diseases is especially disturbing. Viral diseases like yellow fever, dengue fever and many types of encephalitis have been isolated from starlings. Starlings are also one of the many bird species documented as vectors for West Nile virus. Starlings now range as far north as Fairbanks and south through most of Mexico.

This is just an example of how well-meaning folks re-lease a few birds into the wild and the results can be devastating. There was no way to predict the harmful effects starlings would have on our continent when those first birds were released.

So, is it worth the risk to plant a few rabbits or quail in your back yard if they could potentially eliminate native species from the enjoyment of our descendants?

There are some simple steps to stop non-native species from getting established. Don't be tempted when the local pet store has a sale on mallard chicks to buy and release them into the wild. We also should make a concerted effort to remove these birds from the wild when we see them. Give birds the same attention that we give to crawfish or northern pike. We may not know the exact risks they pose, but why wait until they are uncontrollable to react to the threat?

Todd Eskelin is a biological technician at the Kenai National Wildlife Refuge. He specializes in birds and has conducted research on songbirds in many areas of the state.

Previous Refuge Notebook articles can be viewed on the refuge Web site at http://kenai. You can check on new bird arrivals or report your bird sighting on the Kenai National Wildlife Refuge Birding Hotline at (907) 262-2300.

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