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By Joe Robb, Refuge Operations Specialist, Big Oaks NWR
The ORVET Migratory Bird
Subgroup, which includes a variety of federal and state agency and conservation
group partners, initiated the ORVE Migratory Bird Resource Priority GAP
Metaproject to identify areas of importance to species of migratory birds. The
target bird species are mainly songbirds that winter in South America or Latin
America and breed or inhabit the Ohio River Watershed during the spring and
summer. The GAP metaproject will identify areas in the ORVE that are of
particular importance to these species of birds and present the information in
an ArcView GIS database.
Using the GIS
coverage, the group is presently:
-identifying various size
classes of forest and grassland habitat based on PIF and other reference sources
concerning theoretical minimum sizes for the identified species of concern.
-funding a two-year study
to determine the importance of reclaimed strip mine grasslands to migratory
grassland dependent birds, a species of particular concern within the ORVE.
-cooperatively working
with the Central Hardwoods Bird Conservation Region (BCR) to incorporate our
extensive GIS information on breeding birds with their development of a GIS for
the Central Hardwoods BCR.
Central Hardwoods Area
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Ball State Univ. Master
student Cindy Basile measuring cerulean warbler habitat vegetation
photo by Dr. Kamal Islam
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The ORVE team
supported a Ball State University (primary investigator, Dr. Kamal
Islam) study concerning habitat and landscape characteristics of
cerulean warbler territories in Indiana. During the 2001 field season
which extended from 1st week in May through mid-August, 39 cerulean
warbler territories were located, monitored, and mapped, and several
vegetative parameters associated with these territories were measured at
9 study sites (259 ha/site) in the Pleasant Run Unit of the Hoosier
National Forest and Yellowwood and Morgan-Monroe State Forests. In
addition, 39 random sites were selected and vegetative parameters
associated with these sites were collected. An additional 9 birds were
located on territory. However, due to time and weather constraints,
these territories were not mapped. Combining data from the year 2000, a
total of 62 territories (23 in 2000, and 39 in 2001) were located,
monitored, and mapped, and vegetative parameters associated with these
territories were measured during the two-year study. In addition,
vegetative characteristics of random sites were also collected in 2000.
Breeding behavior of cerulean warblers were observed at 5 territories in
2001 (the first year to examine breeding biology in this study) which
included food exchange, male feeding female as part of courtship
display/pair bonding, and female carrying nesting materials. However, no
nests were located at these territories. |
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The ORVE team
supported a study of Bewick's wrens in Kentucky and Tennessee concerning
their current distribution, breeding success, habitat use, and
interactions with house wrens. This was the first year of a 2-year study
by Eastern Kentucky University (EKU; primary investigator, Dr. Gary
Ritchison) funded through Region 4. From 1 May - 15 August 2001, EKU
searched for Bewick's Wrens (Thryomanes bewickii) in central
and western Kentucky and Tennessee. Four birds (one pair plus two
unpaired males) were located in Tennessee, and one unpaired male was
located in Kentucky. The lone pair, located on a farm in Rutherford
County, Tennessee, nested twice and fledged a total of five young from
these two nests. EKU located two unpaired males in an area 24 km south
of the pair. These males sang throughout the summer and defended
adjacent territories and built nests, but both remained unpaired
throughout the season. Vegetation was sampled at nest sites (both used
and unused nests; N = 5) as well as at randomly-selection locations
within the territories. Vegetation was sampled in territories occupied
by wrens in 2001 (N = 4), and vegetation was analyzed in areas known to
be used by wrens in either 1998 or 1999 (N = 7) and in random-selected
unused areas (N = 11). Previously-used locations were identified based
on responses to requests for information on birding listservs in both
Kentucky and Tennessee and on discussions with a number of birders in
both states. EKU observations along with discussions with land-owners
indicate that vegetation had been altered at all previously-used sites,
and these changes likely contributed to the abandonment of these
formerly-used areas by wrens. |
Bewick's Wren
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Bewick's Wren Nest
photos by Michael Hodge
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Other bird studies:
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Bird Banding
Photo by Ron Austing |
Henslow Sparrow Habitat
Photo by Teresa Vanosdol-Lewis |
Swallowtail
Photo by Teresa
Vanosdol-Lewis |
Several other grassland
bird studies were coordinated/reviewed by ORVE team members in the ORVE. The
Henslow's sparrow monitoring work continued at Big Oaks NWR (the former
Jefferson Proving Ground). The study at Big Oaks NWR has monitored 135 Henslow's
sparrow nests during the last 4 years. This is the largest sample of nests ever
monitored for this species. This study has indicated that Henslow's sparrows can
successfully nest in grasslands treated with prescribed fire during the
treatment year, and nesting densities are highest the season following the
prescribed fire treatment. Also some data at Big Oaks NWR indicates that mowing
could decrease nest densities and be a less desirable treatment for nesting
Henslow's sparrows.
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