Maryland Winter Bird Survey
Entry ID:
BRDPWRC0009
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Summary
Purpose:
GOAL: To survey in a uniform manner the wintering bird life of Maryland.
After an initial 6-year survey period, we will develop winter range and
relative abundance maps for diurnal wintering birds. In subsequent decades this
technique will be used to monitor fluctuations, trends, and cycles in
populations. It may also serve to monitor ... emigrations of unpredictable northern
species. The Maryland winter bird survey is to provide an accurate picture of
the winter distribution of birds in a region and will work well in areas with
high volunteer labor pools.
Abstract:
A winter bird survey was conducted throughout Maryland, primarily by
volunteers, during the 6 winters of 1988 to 1993 between the dates 10 Jan and
10 Feb. The state of Maryland is covered by 1231 blocks (9.5 sq. miles each),
each comprising one-sixth of the standard U.S.G.S. 7.5 minute topographic
quadrangle, and 548 of these blocks (44.5%) were surveyed for winter birds.
Blocks were chosen in a systematic pattern with eventually almost every other
block in the state having been surveyed as of Feb, 1993. Volunteers conducted
each 4-hour survey by walking a 4-6 mile route chosen by the volunteer to
sample habitats in proportion to their availability in the block. Surveys began
around sunrise (7:30 a.m.) and all birds seen or heard during the 4 hours were
recorded on data sheets. The data were then used to create maps representing
the distribution and relative abundance of each species of wintering bird found
in at least 10 blocks in the state.
Supplementary Information:
http://www.im.nbs.gov/winter/instruct.html
Geographic Description:
Maryland For the purpose of interpreting the maps, a brief discussion of the
geography of the state and its physiographic regions (see Fig. 1a) follows.
Maryland contains parts of 3 physiographic provinces (Frese 1994): Coastal
Plain, Piedmont, and Appalachian. Elevations increase from sea level to 3360
feet, generally in an east-west progression. The Coastal Plain, part of the
Atlantic Coastal Plain, is further divided on the map into the Upper
Chesapeake, Eastern Shore, and Western Shore sections bordering the Chesapeake
Bay. Elevations there are mostly less than 100 feet, with the topography low
and flat except for the hilly country of the lower Western Shore. Major rivers
are the Patuxent, Potomac, Chester, Choptank, Nanticoke, and Pocomoke, all of
which drain into the Chesapeake Bay. Agriculture predominates, with much of the
land cleared for soybeans, corn, wheat, hay, and on the lower Western Shore,
tobacco. The Piedmont province is sandwiched between the fall line for streams
and the eastern beginnings of the Catoctin mountains. The land is rolling and
hilly, ranging in elevation from about 100 to 800 feet, and is drained mostly
by the Potomac, Monocacy, Patapsco, Gunpowder, and Susquehanna rivers.
Straddling the boundary between Coastal Plain and Piedmont are the heavily
urbanized areas of Baltimore, Maryland, and Washington, D.C., both of which are
surrounded by extensive suburban development that reaches far into both
provinces. The Appalachian Province is composed of the Ridge and Valley and the
Allegheny Mountain sections. The former section is characterized by ridges and
steep mountains running northeast to southwest separated by mostly narrow
valleys, with elevations in the 500 to 2000 feet range. The heavily forested
Allegheny Mountain section is part of the Allegheny Plateau and contains the
state's highest elevations, mostly in the range of 2000 to 3000 feet. Less than
half of the land surface in the state is forested, with oak and hickory
predominating, although Loblolly Pine prevails on the Eastern Shore. Mean
annual snowfall accumulations range from about 100 inches in extreme western
Maryland to 10 inches on the Eastern Shore. January is the coldest month, and
mean temperatures for January and February range between the upper 20's and
upper 30's degrees Fahrenheit.
Methodology:
METHODS: Maryland has been divided into a grid of approximately 1200 blocks,
each about 10 sq. mi. in size. This is the same grid system used in the
Maryland Breeding Bird Atlas project. Each surveyed block will receive 4-hours
of on-foot coverage by experienced birders. Due to the difficulties of
attempting to survey all 1200 + blocks, only the blocks will be covered, namely
a checkerboard pattern of "target" blocks. In the first year, alternate
southern blocks in each 7 minute quadrangle will be surveyed, in the second
year, middle blocks and in the third year, northern blocks. The cycle will then
repeat in the 4th, 5th, and 6th years, to complete the targeted blocks.
CHOOSING A ROUTE: It is important to cover a block in proportion to the
habitats present in the block. For example, if the block contains 40% suburbs,
10% marsh, 10% fields, and 40% woods you should spend about 1 hours in the
suburbs and in the woods and about hour in the marsh and in the fields. Most
blocks can meet this criterion with one continuous 4-hour route. However, if
the habitats present are too scattered, some driving is permitted. Do not
exceed hour of driving time and do not count birds during that time or consider
it part of the total 4 hours. It might also be necessary to retrace part of
your route to sample an important habitat. Again, the time spent retracing
should not be considered part of the 4 hours, nor should birds be counted. A
walking speed of 1-1.5 miles per hour is suggested. Hence, 4 hours of coverage
should be about 4-6 miles. This speed allows time to "work" mixed flocks of
birds, but not to dawdle or sit. Complete roadside coverage is not
recommended, but in some blocks it might be necessary. If a block dictates
largely or entirely walking on roads, it will probably be easy to cover up to 6
miles. If you complete 4 hours of coverage before you complete your proposed
route, stop counting and return to your car. If you reach your proposed end
point before the 4 hours is up, extend coverage, but not along the
already-covered route. If possible, examine the map and scout the area ahead of
time, asking permission if necessary. Plan your route before the actual day of
coverage. TIMING OF ROUTES: In order to keep the surveys comparable, a time
period of 7:30-11:30 has been chosen. This avoids the brief period of intense
bird activity at dawn, and everyone gets to sleep later. The survey can be
extended up till noon to compensate for driving time, as described above.
COUNTING: Each block will be visited once by one observer. A companion may act
as recorder but should not help lure or spot birds. Pishing may be used to
attract mixed flocks but no tapes or owl imitations are permitted. The object
is not to maximize the number of birds recorded, but to survey winter birds in
a uniform manner. Use the field sheet provided, counting all individual birds
seen or heard in each of 8 half-hour segments. If you would rather not carry a
clip board, a small note pad, with a page for each hour will be satisfactory.
In blocks with water, time should not be spent scoping or waiting for birds.
Open water or other special habitats like landfills should be surveyed
following the 4 hours of foot coverage. The results from these special areas
should be written in at the bottom of the form. Waterbirds flying over or in
fields found during the walking portion of the survey should be treated like
any other species. Upon completion of your survey be sure to record all weather
information and mark the location of the route you took on the map. Also be
sure to mark the location of the end point of each hour segment. GENERIC
SPECIES: Winter birds are often difficult to identify to species. For
completeness sake, please record all birds such as crows and gulls that you are
not able to separate by species. REPORTING: After completing the count,
transfer the data to the summary sheet provided, and fill in the weather data.
Total the 8 columns and double-check the species total for each column to make
sure it agrees with the species total for each half-hour on the field sheet.
Please return your field sheets and maps. These maps are from a personal
collection and their replacement is expensive. WEATHER CODES: Please record the
percentage of ground that is covered with snow and the percentage of ice on the
water bodies in your block. Please record wind speed using the following codes:
0 - smoke rises vertically, 1 - smoke drifts, 2 - wind felt on face, 3 - light
flags extended, 4 - wind raises dust and loose paper, 5 - crested wavelets on
inland waters. Please record sky conditions using the following Weather Bureau
codes: 0 - clear or a few clouds, 1 - partly cloudy (scattered), 2 - cloudy, 4
- fog or smoke, 5 - drizzle, 7 - snow, 8 - showers. A FEW PRACTICAL HINTS: If
there is snow on the ground wear waterproof boots. Dress in layers and bring 2
more layers than you think you could possibly need. Bring Chapstick. A
pocketful of "trail mix" can keep your energy and spirits high while walking
those boring fields. Two observers can easily survey different blocks using one
car by establishing pickup locations along a road at the end of the count.
http://www.im.nbs.gov/winter/instruct.html field surveys
Geographic Coverage
Spatial coordinates
| N: 40.0 |
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S: 38.0 |
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E: -74.0 |
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W: -78.0 |
Data Set Citation
Dataset Creator:
Patuxent Wildlife Research Center, Biological Resources Division U.S. Geological Survey ;
Dataset Title:
Maryland Winter Bird Survey
Dataset Release Date:
1994
Dataset Release Place:
Laurel, MD
Dataset Publisher:
PWRC, Inventory and Monitoring Biological Resources Division USGS
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Temporal Coverage
Start Date:
1988-01-01
Stop Date:
1993-01-01
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Location Keywords
Science Keywords
ISO Topic Category
Quality
Data has been completely verified to the best of the investigators'
abilities.
Care should be taken not to over-interpret the edges of the contour
divisions on the kriged maps. The edges of boundaries often look
"busy" with lots of "squiggles" which should be ignored for the most
part. This is due to a choice made in applying the software (e.g.,
... 200-unit grid) to make the resulting surface follow the outline of
blocks, representing the true area surveyed. Thus, the dot maps should
be compared to the contour maps for questionable abundance contours on
the contour maps. The dot and contour maps each describe the data from
a different perspective and, generally, either the dot map or the
contour map is better for any given species, but it will be left to
the reader to decide which map is preferred for each species. However,
any contour map with an asterisk (*) following the figure number
indicates that this map was particularly uninformative, usually
because the species was difficult to detect and was missed in parts of
its range. For these species, the dot map should be used, not the
contour map.
Any contour map with an asterisk (*) following the figure number
indicates that this map was particularly uninformative, usually
because the species was difficult to detect and was missed in parts of
its range. For these species, the dot map should be used, not the
contour map.
Access Constraints
none
Use Constraints
none
Ancillary Keywords
Data Set Progress
Originating Center
Data Center
Personnel
JEFFREY
S.
HATFIELD
Role:
TECHNICAL CONTACT
Phone:
(301) 497-5633
Fax:
301 497-5666
Email:
jeff_hatfield at nbs.gov
Contact Address:
Patuxent Wildlife Research Center
Biological Resources Division
U.S. Geological Survey
11510 American Holly Drive
City:
Laurel
Province or State:
MD
Postal Code:
20708-4017
Country:
USA
TYLER
B.
STEVENS
Role:
DIF AUTHOR
Phone:
(301) 614-6898
Fax:
301-614-5268
Email:
Tyler.B.Stevens at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Global Change Master Directory
City:
Greenbelt
Province or State:
MD
Postal Code:
20771
Country:
USA
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Publications/References
Citation Information:
Originator: Jeffrey S. Hatfield, Sue A. Ricciardi, Greg A. Gough,
Danny Bystrak, Sam Droege, and Chandler S. Robbins
Publication Date: 1993
Title: Distribution and Abundance of Birds Wintering in Maryland 1988-1993
Series Information:
Series Name: Maryland Birdlife
Issue Identification: V. 50, nos. 1-4
Other Citation Details:
pp. 3-83
Methodology Citation Information:
Series Information:
Series Name: Maryland Birdlife
Issue Identification: V. 50, nos. 1-4
Creation and Review Dates
DIF Creation Date:
1998-11-04
Last DIF Revision Date:
2005-02-23
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