Is the RRBO banding program in jeopardy?
As noted in a previous post, this was a challenging season. Due to funding shortfalls, we cannot maintain the banding area as needed, and more importantly our hours have been cut. On banding days, all attention has to be devoted to tending the nets and the birds. We also had to spend time doing vegetation surveys when plants were fruiting throughout the season. As a result, time did not allow me to keep up with all my usual activities. Among things that went by the wayside were posting more regular updates to this blog and social media (I apologize!), and doing data analysis or writing the paper I am currently on, the results of our thrush diet study.
My obligation as a bander and researcher is to interpret and disseminate data we have already gathered; we need to make this a top priority. I have been tasked with raising at least $20,000 this year to maintain our current (reduced) schedule without further cuts. If we face more reductions in hours, we certainly will not be able to band next year. If we can top our goal, I hope we can resolve some of our time and resource issues and band at least part-time next fall.
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| Will there be nets in the net lanes next year? |
The fall 2014 banding summary, part 1: the birds
On to the birds. RRBO banded on 17 days between 18 August and 30 October. We utilized only about two-thirds of the number of nets we usually do, arranging them to avoid the most deer-prone areas to minimize destruction of nets and harm to birds. We still lost some nets but the damage occurred when they were closed and no injuries to birds resulted.
We captured 317 birds of 46 species. Since we tried to band on days when we hoped to maximize our captures of target species (this year, catbirds and robins), our capture rate* was 50.6 birds per 100 net-hours, the highest since 2006. However, cherry-picking days for good conditions, versus banding every day, means that we can't really compare these results with previous years.
We did succeed with our modest goal, as catbirds and robins were the top two species banded. In fact, despite the very limited schedule, our 38 new catbirds banded was a higher total than the past two years, which were dismal record lows. And we got over 40 seed samples from catbirds (more on that in the next post).
The highlight of the season was the Marsh Wren banded on October 9 described and shown in the previous post. A Blue-gray Gnatcatcher on September 15 and a Yellow-bellied Sapsucker on September 29 were other less-common species in the nets. While it's hard to judge without daily banding or surveys, all thrushes, but especially Hermit Thrushes, seemed scarce this fall, as were sparrows such as Lincoln's, Swamp, and even White-throats.
Although on my own time, I thought I would mention that I also banded at a Washtenaw County site previously used for the catbird project. Although using fewer nets than RRBO in 12 sessions for about half the number of hours, the capture rate was higher at 59.6 birds per 100 net-hours, a great result given that we did not choose our banding days based on conditions. We captured 167 birds of 27 species, with American Goldfinch and White-throated Sparrow being the top species. I am experimenting with this site for several reasons: to test the potential as a back-up for RRBO's campus site, to collect fecal samples to determine diet at a site less-invaded by non-native species to compare with RRBO's data, and to train an enthusiastic future scientist, Aspen Ellis.
Aspen is a UM-Ann Arbor student who has already accumulated a lot of varied ornithological experience: for many years she has prepared bird specimens at the University of Michigan's Museum of Zoology, and she has worked on Audubon's long-running Project Puffin as a research assistant the past two summers in the Gulf of Maine. Aspen's dedication to birds and science has been recognized by the Tim Schantz Memorial Foundation with a scholarship to Alaska to present her puffin experience, and the American Birding Association in their Young Birder of the Year contest. Read about her experiences and goals in her own words here at the eBird website.
Banding in Dearborn wasn't very practical for Aspen around her school schedule (and that of the family's cars!). But her clear commitment to bird conservation and science and her maturity spoke to me, and using the Washtenaw County site -- very near her home -- was the answer. It was a pleasure working with her. She is a fast learner and was mastering the basics as the season drew to an end; I hope we can continue the process next year.
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| Aspen and a female Eastern Towhee. |
Part 2: the fruit data
The paper I am working on now is looking at seeds from fruits in the diets of over 300 Hermit and Swainson's Thrushes. I began with them because my previously published paper documented weight gains in these species. Meanwhile, we are still collecting data on other bird species. We have good samples sizes from catbirds (over 200), and a great data set for robins (well over 1000 from the fall seasons alone). Since catbirds and robins nest here, we would like to see if the fruit in their diets differs from the thrushes, which are only here during migration. Since we also have data for robins from summer and winter, we can also look at how their diets change throughout the year. We have also collected over 1000 specimens at the Washtenaw County site for comparison.
I will summarize a very demanding and interesting season of data on fruit availability and diet sampling in my next post.
A huge thank you to two people. First, Dana Wloch returned for yet another year of banding and seed processing. This year, measuring fruits and their seeds was added to her repertoire. In past years, she has been supported by grant money. This year, she came in several days a week as a volunteer. Truly, I would have gone insane without her. At the Washtenaw site, my husband Darrin O'Brien forfeited his Sundays to help out banding and training Aspen. Darrin is a talented bander...and every new bander should get more than one perspective!
*In order to compare different locations or years that may operate the same number of hours but with more or fewer nets, capture rate is calculated by "net-hours." One net hour is one 12-meter net open one hour, or two 6-meter nets open one hour, etc. This rate is often expressed per 100 net-hours for more manageable numbers.
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