Excerpts from Summer 2009

The President's Message

by Tim Armstrong

A recent article in Refuge Update brought home the impact of nonnative species on refuges across the country. The article described efforts in Florida to slow the spread of Burmese pythons onto refuges near Everglades National Park. The park is currently estimated to have a population of 20-30,000 pythons, which are eating everything, including alligators, deer, and endangered Wood storks. Like some other nonnative species that have gotten established in the US and other countries, the pythons started off as someone's pet. When they get too big, some well-meaning people release them into the wild instead of trying to find another home for them or euthanizing them.

My first introduction to the problem with pythons in the Everglades was two years ago when my younger son Ben and I were visiting family in south Florida. We were returning to Naples from the Keys when we saw a huge road-killed snake on Alligator Alley. We stopped to look at it, but I was unable to identify it conclusively, other than to know it was certainly not a native snake. Until this recent article, however, I had no idea of the extent of the python problem.

Compared to thousands of 20' Burmese pythons, our local nonnative species problems may seem trivial. Refuges in the San Luis Valley contain a variety of nonnative plants, including Canada thistle, white top, leafy spurge, tamarisk, and Russian olive to name a few. The impacts of these species vary: some are noxious to grazing animals, others use large amounts of water that are no longer available to native plants. The biggest impact is that without the natural controls like herbivores, predators, and disease found in their native habitats, many of these plants simply out compete native plant species, which form the basis of our plant communities. For the refuge system, the biggest impact is the cost of containing nonnative species, effort that could otherwise be spent improving habitat and managing native species.

Other familiar nonnative species in the San Luis Valley include feral house cats, bullfrogs, House sparrows, and European Starlings. Many house cats, which are native to Africa, are allowed to roam free, where they prey on rodents and small birds. Some estimate that feral cats kill hundreds of thousands of small birds in the US each year. Bullfrogs, which are native to the eastern US, are thought to have been brought to Colorado as bait by anglers. House sparrows and European Starlings, both native to Europe, were released in the eastern US many years ago, and have since spread across the US. Here, they out compete many of our local cavity-nesting species like Bluebirds and Tree swallows. Interestingly, House sparrows are declining in England and conservationists there are trying to save the population. I wish we could just send them all of ours. We are most familiar with terrestrial nonnative species, but in the aquatic world, things are worse. Many species of fish with which we're familiar, including carp, rainbow, brown, and brook trout, are not native to Colorado. Again, these nonnative species have displaced native species like the Rio Grande cutthroat, chubs, and suckers, which are currently considered species of special concern by the state. The Baca refuge contains important, genetically isolated populations of Rio Grande chubs and suckers that were undiscovered until the refuge was established. Historically, popular sport fish like rainbow and brown trout were introduced widely with little concern for native fish. As recently as the 1960's, biologists were actively trying to remove native fish to make way for nonnative sport fish in the Colorado River. Today, we are doing the opposite to try to recover populations of native fishes, which may play critical roles in their native habitats.

The spread of nonnative fish is complicated by anglers who transport their favorite fish to new locations when they travel. One of the most infamous examples of this so-called "bucket brigade" resulted in the introduction of lake trout into Yellowstone Lake in Yellowstone National Park. The nonnative lake trout have decimated the local population of cutthroat trout, triggering a massive effort to remove the lake trout.

Another example of a nonnative aquatic species introduced into Colorado is the parasite that causes Whirling disease. Whirling disease originated in Europe, and was introduced into the US in the early 1900's. Since that time, the disease has spread across the US, where it has devastated native and nonnative trout populations.

You may be familiar with the recent spread of Zebra and Quagga mussels into Colorado. They are thought to have been introduced into the Great Lakes region in the ballast water of ships traveling from Asia. From the Great Lakes, they have rapidly spread across the US. The economic and ecological cost of these mussels is enormous. They reproduce so rapidly that they clog intake pipes of water treatment facilities and degrade mechanical equipment. Ecologically, they change the entire structure of lake ecosystems by removing large amounts of plankton by filter feeding.
Whether we like it or not, many of these nonnative species are here to stay. Once they are established, often times the best we can do is try to control their spread. Experiments are underway to try to find biological ways of controlling nonnative plants like importing insects from the plant's native region, but I always worry that these efforts will result in more unforeseen problems with yet another nonnative species.

So what can be done? On a personal level, we can reduce the spread of nonnative species by not releasing pets into the wild, not using nonnative plant species for landscaping, not transporting fish or bait between lakes, and cleaning or disinfecting our boats, shoes, and fishing equipment after each use. On a national level, we can lobby our representatives to pass legislation that would reduce the number of nonnative species entering the country, and for money to help control the spread of nonnative species already present. We may have to live with many of the nonnative species already established, but we certainly don't need any more.

Results of 2009 Spring Bird Count

By John Rawinski

The 19th annual San Luis Valley, Colorado spring bird count held on Saturday, May 9th, 2009 found some rare and unusual bird species. The count was done as part of the International Migratory Bird Day celebration, a cooperative effort between State and Federal agencies. The count tallied a total of 148 species, which was the fourth highest count in the 19 years of spring counts. Total numbers of birds counted, however, was lower than average with 7,182 individual birds being counted. Last years count produced 151 species and 18,458 individual birds. Lower total numbers may be due to spring storms that delayed some bird arrivals.

A Pectoral Sandpiper was found, which is rare in the San Luis Valley. It was a count-first, a first spring record, and one of four records for the San Luis Valley. The Pectoral Sandpiper is a migrant through our area as they migrate toward breeding grounds in the arctic. A male Summer Tanager at the Alamosa River was only the 10th record for the Valley. A Black-and-white Warbler found in Saguache is only the 11th record for this species in the valley. A male Lazuli Bunting was found at feeders in Blanca and this species is considered unusual in the Valley. Other unusual species included Northern Waterthrush, Red-necked Phalarope, Burrowing Owl, Canyon Wren, Lewis's Woodpecker, a dark phase of Ruddy Duck, and Gray Jay.

Count-organizer John Rawinski, volunteering for the Rio Grande National Forest, said "The Pectoral Sandpiper is not a big bird by stature (about 9 inches), but is a "big bird" to find in this Valley". This bird is likely feeding and recharging its energy reserves before it resumes the migration marathon back to the arctic. "One of yesterday's gems was the male Lazuli Bunting, a beautiful blue bird with a reddish brown breast that fed at a feeder in Blanca … we just don't see those birds very often," said Rawinski. Another astonishing trend was the lack of birds in the local heronries. "Where in many years we have had hundreds of nesting White-faced Ibis, Snowy Egrets, and Cattle Egrets, we had less than 10 birds present" said Rawinski. "This sudden downward trend is a concern and could be due to a number of factors, such as late arrivals, water, and environmental conditions" said Rawinski. Fifteen persons participated in this year's count, which was about average for the count

Annual Eagle Survey

by Scott Miller, Refuge Biologist

The 2009 mid-winter eagle count took place in the SLV on January 9 and 10. This year, a total of 67 eagles were counted along 958 miles of survey route. Of the 67 total eagles counted there were 52 adult bald eagles, 6 immature bald eagles, 6 adult golden eagles, and 3 were of unknown species or age.

The majority of the bald eagles counted were found south of the Monte Vista NWR in the Carmel area, along the Alamosa, San Antonio, and Conejos Rivers and near the Peterson Springs area (about 4 miles west of La Jara). Most of the golden eagles were found in the north eastern portion of the SLV along the Closed Basin Canal. Interestingly, no eagles were counted on the Alamosa NWR along the Rio Grande River this year.
Compared to the last few years, the major rivers in the SLV and the Closed Basin Canal were more ice-free over larger sections of the rivers due to milder temperatures. Overall, the total count was higher than last year but a bit lower than the long term average (approx 120 eagles).
The San Luis Valley NWR Complex would like to extend their appreciation to Michael D'Errico, Cary Aloia, Jenny Nehring, Lisa Rawinski, and Jacob Truetken for helping with this year's survey. Scott Miller (Refuge Biologist) and Floyed Truetken (Refuge Manager) from the SLV NWR Refuge Complex staff also helped with the survey.