Field work, fall 2014

We have been dividing our time here at RRBO censusing and measuring fruit, and banding birds in order to collect the seeds of fruit eaten by the birds.

I know you want me to show you bird stuff first!

Bird of the season so far goes to this Marsh Wren, only the second ever banded by RRBO; the other one was in 1999. Since there are essentially no marshes in Dearborn, this is not a common species here, and this is only the 7th record. Probably the coolest thing was the amazing sound this bird made. I took a short recording -  click here to listen (it's a m4a file, but I can play it with Windows Media Player).

One of the most interesting warblers I've banded lately was this adult female Black-throated Blue Warbler. In dimorphic species, sometimes older females can have relatively male-like plumage. This gal had a lot of blue tones in her feathers, a darkish face, and a very large white "hanky."

Orange-crowned Warblers are always nice -- one of the treats of late fall.

We catch very few Yellow-bellied Sapsuckers -- this is the 6th in over 20 years -- so this youngster was fun to see. Woodpeckers tend to hammer on your fingers, and the very fine, chisel point of a sapsucker bill is an effective weapon...

 

...although nowhere near as formidable as the powerful bill of a Rose-breasted Grosbeak. We always give grosbeaks a lot of respect!

One thing we always look at when trying to determine the age of birds is whether there is contrast between old and new feathers. In the photo above, it's easy to see the four paler, more worn wing feathers, which she has not replaced this year, and how they contrast with the new, fresher, darker wing feathers. The new feather in the middle that is a bit shorter is still growing in.

Onto the fruit. Our analyses of seeds found in the fecal samples of birds requires context: some sort of compilation and rank abundance of all the ripe fruit available to birds to eat when they are present in the area. Each year, we estimate the percent of ripe fruit on the common species once a week or so throughout the season. This year we are making sure we have complete data on all fleshy fruits available, even if they have not shown up in fecal samples -- all together around two dozen species. For less-common fruits, we have tried to locate and count all individual fruit, once a week. For abundant species, we cut down branches, counted all the fruit, and came up with an average for a "representative" branch. Then we go out and count the number of representative branches each week in a 200 meter circle centered on our banding area.

I can tell you that this work falls under both "tedious" and "easier said than done." It is not precision work (and it varies annually depending on fruit crop), so what we'll end up with is a list in approximate rank abundance, based in categories that increase by orders of magnitude. Even with that crude ranking, it's not easy and very time consuming. Much of our counting is done along a busy public bike path. People are intrigued when they see one of us standing and staring at the vegetation for long periods of time; they inevitably ask us what I am looking at. I know I have become much more adept at writing down my fruit counts and keeping track of where I am so that I can stop and explain what I'm doing.

How many ripe multiflora rose hips are just
in this one bush?

We also take various measurements of the fruits of each species throughout the season: the diameter of individual fruits, how many seeds they contain, and the diameter of the seeds. This can help us understand what size fruits are favored by different bird species, if they prefer fruits with a few large seeds or more small seeds, etc. Some fruits are simple: the shrub dogwoods are typically 5 to 8 mm, and have one seed. Then there are fruits like Climbing Nightshade (Solanum dulcamara), which have around three dozen, 2 mm seeds each! All get dutifully counted and measured. 

We start on Monday, spend at least one full day just working on fruit, and finish as best we can on days we band. Due to our funding shortfall, our days have been cut back so we are cramming as much work in as possible.

These tasks would not be possible without the help of Dana Wloch, who first started with RRBO as an undergrad, then under several grants, including one where she helped develop our seed identification website, and now is back as a volunteer. Thank you, Dana! We are the dynamic fruit duo of Dearborn.

RRBO update

It's been awhile since I've posted an update due to some changes here at RRBO.

As has been the case with many non-profits, fundraising has been particularly challenging over the past five years or so since the recession. While things have improved recently, RRBO's funding shortfall has forced us to reduce our operations. We're doing our best to try to prioritize research activities on our curtailed schedule. One goal is to finish a solid version of a major paper on the diet of Hermit and Swainson's Thrushes on fall migration. Most of the analyses and a big chunk of the writing is done, and this fall we are working on the last of our fruit crop surveys and fruit/seed morphology work (more on that in another post) which is both time-sensitive and time-consuming! Our fall banding has been focused on catbirds and robins, as these can be the subject of another paper.

Two things have further limited our banding program this fall. After 7 years, the plastic deer fencing that we found necessary to install around the banding site has finally deteriorated so that we are no longer able to repair it. Given the current circumstances, we don't have the resources to replace it. The deer herd has grown substantially since the fence was put up, and due to major construction on the other end of campus, many deer are in and around the banding site. We're using fewer nets and reconfigured them to (hopefully) minimize potential damage, conserve our equipment, and provide a safer situation for birds.

Second, in early August we discovered that someone had dumped 10 or more cats around the Environmental Interpretive Center, and had also been feeding them. This is a tragedy for both the cats and the wildlife. We cannot band birds when there are free-roaming cats in the area, and it takes considerable effort for us to trap these cats, if we can at all.

Therefore, we are doing limited banding here on campus as well as at the Washtenaw County site we used last year for the catbird study. Speaking of which, while we did see a number of catbirds banded in previous years this spring and summer, we only saw one returning bird with a geolocator, and many attempts to recapture it were unsuccessful. Many of our catbirds return multiple years, and the batteries last on the geolocators for two years (and even if dead, the data can still be accessed). We may still get one this fall; otherwise we will have to see what happens next year.

Somewhere in the mix, I have to squeeze in our annual fundraising campaign. The goal is to increase support by 30% in order to avoid further cuts and furloughs. But you don't have to wait -- visit this page on the RRBO web site to learn how to make a gift today!