Wednesday, February 06, 2013

Sparrow Banding

Between January 26th and January 29th, we were banding sparrow species in a variety of habitats.  Mark LaBarr, Audubon Vermont and a federally certified bird bander, flew down to coordinate the proceedings and band the captured sparrows.

In the eastern United States, grassland habitat continues to disappear and consequently bird species that prefer that habitat are also in decline.  Previously, we have reported on our efforts to restore grassland habitats within the Francis Beidler Forest.

The four days of banding began at the recently burned Spring Branch grassland restoration site.

Unburned and burned Spring Branch - Mark Musselman
Lex Glover removing sparrow - Mark Musselman
Other certified banders, Lex Glover of the South Carolina Department of Natural Resources (SCDNR) and Aaron Given of the Town of Kiawah, were on site to assist with the banding and data collection, but the significant help came from the Summerville High School Navy Junior ROTC volunteers.  The effort to capture and band sparrow species is not like some netting stations which are situated to be in the flight paths of birds conducting their normal activities.  Sparrows spend the majority of their time on or quite close to the ground, so they need to be flushed from their cover towards the mist nets.  That is where the extra bodies proved to be invaluable.

Purple line shows track of Mark Musselman during the day of banding
The middle of the three sections shown above in orange was the only section not burned.  The nets were initially set along the fire break to the west and set later along the fire break to the east.
Summerville HS NJROTC volunteers - Mark Musselman
With the large grassland habitat and small coverage area of the mist nets, the sparrows would have had no trouble leaking around the three banders and three Audubon staff members trying to drive the birds towards the nets.  However, with the quantity of high school volunteers joining the effort, we were able to cover a wide swath of the grassland and curl in the ends of the line to keep the birds moving directly away from the noise and humans and towards the waiting nets

The majority of the approximately 60 sparrows captured were Song Sparrows and Swamp Sparrows.  However, there were also several Savannah Sparrows and one Grasshopper Sparrow as well as an overly curious Northern Mockingbird.  The mockingbird was shown to the students and released without any bands, but all sparrows were given an official United State Geologic Survey (USGS) band.  You can read more about the North American bird banding program here.

Mark LaBarr with Northern Mockingbird - Mark Musselman
Savannah Sparrow - Mark Musselman
Grasshopper Sparrow - Mark Musselman
Grasshopper Sparrow - Mark Musselman
The second day of banding include a shut-out at the Longleaf Pine restoration site.  The emerging pine habitat still has a significant number of short oaks and wiregrass ground cover, which is clumpy and not nearly as dense as the grassland habitat at Spring Branch.  A return to Spring Branch later in the day resulted in additional sparrows being captured and banded, but without the large number of volunteers, we did not capture anything close to the numbers we saw flying over and around the nets and the six humans.
Clark tract - Longleaf Pine restoration
Days three and four were spent at the Oakridge landfill in Dorchester County and the Bees Ferry landfill in Charleston County.  Although landfills seldom, if ever, evoke images of wildlife habitat, they can be beneficial to some species once portions or the entire landfill have been closed.  Once a section or cell of the landfill has been capped, grasses are encouraged to grow on top and on the sloped sides in order to prevent erosion of the capping material.  Trees, however, are no allowed to grow as their roots would penetrate the capping material, which would allow water in and pollutants out of the waste cell.  Driving the mist net poles in to the ground would have the same effect as tree roots, so the poles needed to be set in buckets of sand.  This sounds good in principle, but the occasional gust of wind would topple at least one pole, which would in turn pull down several others.  Valuable time was then spent picking grass, twigs, and blackberry stems from the delicate nets.
Oakridge Landfill
Oakridge landfill has the distinction of having the highest point in Dorchester County at an elevation of 255 feet.  The small grassy lump in the left half of the panorama below is that high point.

Panoramic view from top of Oakridge landfill - Mark Musselman

Methane capture - Mark Musselman
Mark LaBarr removing sparrow - Mark Musselman
Setting mist nets - Mark Musselman
House Wren - Mark Musselman
Although we did not take pictures of the second site closer to the top of the landfill (see panorama above) was much more like an open grassland.  The site was full of sparrows, but we were again plagued with a limited number of bird drivers.  Additionally, the steep slope worked in the birds' favor.  When flushed from their cover, the birds flew straight out before diving back down for cover.  Unfortunately, straight out put them over the top of the mist nets running parallel to the contour of the hill.  The sparrows were not captured and banded, but their presence was noted and the habitat deemed suitable for grassland sparrow species.

Bees Ferry landfill was the site of the final day of banding.
Bees Ferry Landfill
Help from a variety of volunteers made it possible to set the poles and nets on an increasingly windy day.  Like the Oakridge landfill, poles could not be set into the ground to avoid puncturing the cap and or lining material.  Now, with an ample force of volunteer bird drivers, we lacked the bird numbers we had seen on previous days!

Mark LaBarr removing sparrow - Mark Musselman
Mark LaBarr setting nets - Mark Musselman
Volunteers helping set nets - Mark Musselman
First for Mark LaBarr, Le Conte's Sparrow - Mark Musselman
The day began with a breeze and the winds continued to increase in advance of the approaching cold front.  Setting the nets, already difficult with the sand-in-bucket system, was all the more frustrating due to the random gusts of wind.  However, Mark LaBarr was able to band his first Le Conte's Sparrow and landfill supervisor, Ron Tibbetts, was able to release one of the banded sparrows.
Mark LaBarr helps Ron Tibbetts release sparrow - Mark Musselman
Setting net at second site - Mark Musselman
Although wind and manpower prevented all of the observed sparrows from being captured and banded, we were successful in determining the general usefulness of a variety of grassland habitats to support wintering sparrow species.  In the end, sites like the landfills might mow less, which would save them money (salaries, fuel, maintenance) and provide better habitat for bird species in search of a winter home.

The birds banded over the four days will soon be heading north to establish breeding territories.  It's a long shot, but it is possible that Mark LaBarr could capture in his springtime nets a bird he first met here in South Carolina!

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