Bird Surveys at The Teller: Who's In and Who's Out at the Riparian Exclosure

By Sharon Ritter, Volunteer

Wanted:  Birds. Room and Board Provided.

That's right, Teller has hung out the sign that they are open for business and hoping the birds will notice-if not today, then soon. In 2007, staff and volunteers at Teller cleared a perimeter around a patch of cottonwood river-bottom forest and installed an electric fence. The goal of the fence is to keep browse-munching deer away until existing and planted shrubs and seedling trees have a chance to grow beyond their reach.

The Teller is interested in monitoring the response of the vegetation and how that relates to birds. The Teller recently set up photo points to document vegetative changes over time. Teller staff asked me if I'd like to do seasonal bird surveys on study plots inside and outside of the exclosure to document birds using both areas.

Sam Lawry and I visited the site and looked for an area similar in size (4 acres) and habitat to what was in the exclosure. The only possibility was immediately next to it. This is unfortunate, because it means that birds are likely to have territories that overlap the two study plots, making it hard to detect any differences in use over time. I then set up a survey protocol to use each time I visit. Prominent at the top of the protocol is the instruction that before I head into the exclosure, I need to turn off that electric fence!

I'm doing four surveys a year, one in September to capture fall-migrating birds, one in December or January for winter residents, one in April to be sure I detect woodpeckers, and one in June for breeding birds. I had to skip the winter one this year, so the results I'm reporting are for September, April, and June counts.  This is not a scientifically designed study, but we hope the results of the monitoring will, over time, show the advantages of allowing the riparian habitat understory to recover without pressure from deer.

So far, I've recorded 23 species on both study plots combined and an additional 12 species that were nearby but not on either plot. Several of these nearby species are ones I predict will show up within the exclosure once there's a better understory of shrubs, such as Cassin's Vireo, Common Yellowthroat, Gray Catbird, and Black-headed Grosbeak. Of course, they may already be visiting the plots but just not while I was there.

Of the 23 species, 18 occurred on the plot outside the exclosure and 18 inside. Five just occurred outside the exclosure and five just occurred inside. Even the numbers of individuals were close, with 54 outside and 59 inside. Because the plots currently are pretty similar, I don't expect to see many differences yet. Eventually, after I have more data, I'll look more closely at which species are where, especially which species are taking advantage of the understory as it develops inside the exclosure.

This is a fun project for me. I've been volunteering at Teller for almost 10 years, and am excited over recent habitat improvement efforts like those at the wetlands and deer exclosure. I'm glad I can lend my birding expertise to this monitoring work.

Here are all of the species I've seen so far on the study plots.

Species observed September 2007, and April and June 2008