Report from the Seeley Lake Banding Station

Overview of the Wings in the Wetlands Program
The Wings and the Wetlands Program was launched in the summer of 2001 when WREN initiated a bird banding station at the north end of Seeley Lake, a wetland preserve.  Through this program the public has been invited to observe, and even assist with, quality bird research.  This banding station is operated in accordance with the standardized protocol of the Monitoring Avian Productivity and Survivorship Program (MAPS), a collaborative program with a network of over 500 stations across North America.

Each summer from 2001 through 2005 we’ve captured and banded songbirds on eight banding dates between early June and early August.  The MAPS protocol has numerous measures that promote consistency among stations, such as spacing banding dates approximately 10 days apart, operating exactly 10 mist nets, and opening nets a half hour before sunrise and closing them six hours later.  For every bird captured in a mist net a biologist or trained volunteer carefully removed the bird from the net, placed it in a cloth bag, and brought it back to the banding station where we recorded as many as 18 different kinds of data.  First we placed a small, light weight aluminum band on each bird’s leg; these bands are issued by the USGS Bird Banding Lab and each has a unique number that will identify the bird the next time it is captured.  Some of the most important information collected was the species, age, sex, and whether or not it was in breeding condition. 

If you’d like to learn about some of the data we’ve collected over the past five years, just keep reading.  If you’re interested in visiting our station or helping out with data collection please check back on our website in April for our 2006 banding announcement. 

How many birds do we catch? 
During the summers of 2001-2005 we captured and banded nearly 1500 individual birds from 51 different species.  We recapture many of these birds, both within the same summer and in subsequent years, bringing our total number of station captures to 2125 (TABLE 1; download .pdf ).  For 17 species, we captured more than 20 individuals; the five most commonly captured species were the American Redstart, Yellow Warbler, Swainson’s Thrush, Common Yellowthroat, and Song Sparrow (Fig. 1). 

Why do we catch the birds we catch? 
Why is the American Redstart our most common capture?  Why don’t we catch more Dark-eyed Juncos and Western Tanagers- birds we know are abundant in Montana? 

This banding station sits at the north end of Seeley Lake where the Clearwater River flows into the lake.  Anyone who has ever floated the Clearwater Canoe trail knows how slow and meandering the river is here, and this sinuous path has the dual advantage of creating a nice relaxing canoe trip as well as a unique habitat type, a willow flat.  Willow flats are among the most productive wetland habitat types, providing both abundant nest sites and protein-rich food resources.  At least 14 species, including 10 of the most common birds we capture (e.g. American Redstarts, Yellow Warblers, Swainson’s Thrushes, & Song Sparrows), build their nests in the willow shrubs so abundant here. 

In addition, a majority of birds raise their young almost exclusively on aquatic and terrestrial insects, especially the larvae of Lepidoptera.  These kinds of insects are abundant in willow habitat, and it is likely that at least 30 different species, including all of the 17 most commonly captured species (all except Red-naped Sapsuckers), spend time foraging for insects and larvae in the willow flat habitat.  Thus, the willow habitat at Seeley Lake provides both high quality food resources and abundant nest sites for birds. 

Why do we catch such so many different kinds of birds?
Two factors contribute to both the density and diversity of birds species captured at the Seeley Lake banding station.  The first factor is simply the presence of a super-productive habitat type: the willow flat described above.  This high quality habitat provides resources for both large numbers of birds and a diversity of bird species.  The second factor is that the Seeley Lake banding station is located at the intersection of three different habitat types- willow flats, conifer forest, and mixed deciduous-conifer forest.  Each habitat provides different types of food resources and nest sites that are used by different bird species.  For example, Red-naped sapsuckers and other woodpecker species key in on the aspen trees within the mixed deciduous-conifer forest for both nest cavities and foraging.  Varied thrushes, Townsend’s warblers, and Ruby-crowned Kinglets spend most of their time foraging in the canopies of conifer forests.  By placing some of our nets within each of these three habitat types, we were able to learn about a diversity of species. 

What can we learn from capturing birds? 
Capturing birds can tell us more than just the names and relative abundances of the birds that make their summer home at Seeley Lake.  We can also get an idea of the proportion of the bird population that is breeding and how breeding condition changes across the summer and across years.  When we capture a bird, we can determine whether it is in breeding condition by looking for a brood patch (link to definition below) in females or a cloacal protuberance in males.  At the height of the breeding season, in late June through early July, over 80% of the adult birds captured at Seeley Lake are in breeding condition (Fig. 2). 

We can also learn something about the number of young birds fledged at Seeley Lake by comparing ratios of adult and juvenile birds captured throughout the season.  As you can see in figure 3, we catch very few juvenile birds before early July, but by early August juvenile birds make up greater than 50% of our captures!  This is both because there are so many juvenile birds out there (if every breeding pair successfully fledges an average of 4 young then there should be twice as many juveniles as adults) and because some migratory adults have already started to depart for wintering grounds.  Further, these ratios of adults to juveniles vary among species – for example, juvenile birds make up 36% of all Song Sparrows captured, versus only 11% of all Swainson’s Thrushes captured.  This could be because Song Sparrows are having greater reproductive success, but it could also be that juvenile Swainson’s Thrushes are less likely to be captured (e.g. they fledge later in the season, forage in different places, etc.).  Although our banding data can’t explain why we catch more juvenile Song Sparrows than Swainson’s Thrushes, it has produced an interesting result that could lead to future research. 

Stories about the birds we catch
When we capture a bird, the first thing we do is to place a small, light weight aluminum band on the bird’s leg.  This band has a unique number, so that if the bird is ever recaptured it can be identified.  The vast majority of birds that are banded are never recaptured outside of their original capture location, but on July 16, 2005 we captured Red-eyed Vireo #1561-86528, a bird that was originally banded in Elm Creek in south-central Nebraska on May 28, 2002. 
           
We do however recapture a sizable proportion (30%) of birds originally banded at our station.  Below are some stories about six different birds we have recaptured at least five times, as well as some interesting life history facts. 

Click on a bird to learn its story!