Birds of Seabrook Island



  US F&W Band


Species Acct.
NW Warblers


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How Do You Catch Birds?
  Nests and Young
  Mist Nets
  Cannon Nets
   Body Fat Index
Field Observation
Diurnal Variations
Annual Variations
History - Marking Individuals ("Ringing")
  For many years, observers have used unique features to identify and follow individual birds - a broken leg, fish line around the neck, etc. As techniques were developed to harvest native birds for food, others intentionally marked their captures and released them to follow them around their territories or to see if they returned in future years. John J. Audubon placed silver threads on the legs of nestling phoebes near Philadelphia and found two of them returned the following year. In 1902, Paul Bartsch banded Black-crowned Night Herons. However, the real pioneer was Jack Miner who banded 20,000 Canada Geese on his waterfowl sanctuary near Kingsville, Ontario, in the early 1900s. Waterfowl are particularly good candidates for marking because hunters recover a significant proportion of those banded (10-20% or more). In contrast, small passerines yield few recoveries (discovery elsewhere) and only several returns (discovery at a later time in the area where they were marked) - less than 1%.
   In 1909, the American Bird Banding Association was formed to organize banding activities ("ringing" in Europe). In 1920 The Bureau of Biological Survey (now the US Geological Survey) and the Canadian Wildlife Service took over integrated marking activities and record keeping. Click for more information.
   The scientific interests of most banders has centered on gathering information about migration and, more recently, population phenomena. In general, mensural information, mass, plumage status, parasites, and other observations of a captured individual may be more valuable than marking per se because so few individuals are recovered.
   My own studies concentrated on population energetics and adaptations for surviving the annual cycle of the physical and biological world. As a graduate student, I also banded several thousand colonial seabirds (mostly Herring Gulls, Larus argentatus). Returns from these birds facilitated subsequent studies of populations and dispersal in this species.

How Do You Catch Birds?



  Many migrants move along temperature gradients, traveling north or south between breeding and wintering grounds. When they encounter mountains or coast lines, they often move parallel to the feature (a "leading line"), concentrating in vast numbers in passes or on peninsulas that extend into an ocean or lake. In Europe, the Helgoland Bight (and the Vogelwarte Helgoland, a current research station located on the bight) is famous for focusing migration. In the United States, Point Pelee on Lake Erie has similar migratory dynamics. Cape May is especially well-known for fall migrants on the East Coast.
   In park-like areas of low vegetation, early investigators built narrowing side fences converging into a covered area where birds could be captured. Migrants wander into this trap and are be driven by beaters into narrower covered funnels where they are trapped and marked. This structure is known as a Helgoland trap and has been used at other sites, including Point Pelee.
  Many other ingenious ways were developed to capture birds - nets, snares, decoys, ... and fall traps. To the right, a simple metal structure is propped over a Killdeer nest. The settling bird is unable to get onto the nest without bumping the stick and is then trapped beneath the wire structure.

Drumlin Farm, South Lincoln, MA.

Drop Trap Killdeer nest
    Drop trap Killdeer nest with four eggs
    In winter, birds cannot be netted (they cannot maintain their body insulation with the feathers disturbed and quickly become hypothermic). There are a number of traps that have been developed to capture birds. For small birds, Potter traps (small cages with a treadle operated door, below - right) can capture individuals. Maze traps like the Mason trap (below - right) can capture a number of birds at the same time.
Window traps Ground traps  
Window feeders (New England, Massachusetts Audubon Society - Louise Ayer Hatheway School of Conservation Education) can have Potter traps placed on them. These were used to capture Black-capped Chickadees but they are good for a number of seed-eaters including Purple Finches and nuthatches. Birds can also be observed to study behavior while they are feeding from the inside if the room is darkened . Click for another view. A Mason trap (near Lewisburg, PA) has a center runway 1.5-2" wide and 2" tall that opens inside the trap area. Numbers can be captured at one time - here two Tree Sparrows and one junco are inside the trap. Note there is also a sparrow in the Potter trap. By setting Potter traps alongside the Mason trap, birds walking along the side of the trap are also directed into the Potter trop - we've even captured Loggerhead Shrikes in this way.


Nests and Young

  It is also possible to band young birds. Precocial young like gulls can be banded when about a day old (earlier and the band slips off). Altricial young (like sparrows) need to be 7-8 days old (if banded earlier, the adults mistake the band for a fecal pellet which they remove from the nest, along with the attached chick - if banded later, older young may be induced to fledge prematurely by the disturbance, leading to increased mortality..
  Embarking Herring Gull chicks Cormorant chicks

  Hans Kluijver and Peter Mott prepare transportation for getting to Milk Island, MA. (Milk Island is on the horizon.) June 1957... Two Herring Gull, Larus argentatus, chicks (4-5 days old) sheltering alongside driftwood. Milk Island. These have been banded.
Double-crested Cormorant, Phalacrocorax auritus, chicks - Milk Island. Note bands (size 8 - big ones) on one chick.
    Black-crowned Night Heron chicks Night Heron chick Petrel burrow
    Black-crowned Night Heron, Nycticorax nycticorax, chicks. About a week old but too young to band. These young are hiding from the observer at the edge of their nest. This nest was low but many may be high and difficult to reach. Also on Milk Island. An older night heron chick form the clutch to the left, ready to band. Chicks participate in their defense by urinating on potential predators and presenting them with partially digested meals.

Exploring a petrel burrow. No success!


Great Egret chicks

Great Egret, Ardea alba, chicks, Jenkins Point. These chicks are old enough to band but the nest is high over a lagoon and reaching them would likely destroy their nest (and the nest of others in the colony).

Golden Eagle chick

Golden Eagle, Aquilla chrysaetos. 4-5 weekEastern Bluebird, Sialia sialiss of age. Horsetooth, CO.


Song Sparrow nest

Song Sparrow, Melospiza melodia, nest. One chick hatched - too young to band. 

Eastern Bluebird eggs

Eastern Bluebird, Sialia sialis, nest with 3 eggs. Nestlings can be color banded and followed.

Patricia A. Gowaty, weighing a bluebird egg. Clemson
       Banding young requires them to be accessible in the nest. Precocial young produced by many waterfowl and galliform (chicken-pheasant-like) birds leave the nest and would need to be captured afoot. Margaret Morse Nice, a Columbus housewife, studied Song Sparrows along the Olentangy River in the 30's and produced the first really critical study of breeding biology of a passerine. When asked what she would do differently if she repeated her work, she said "use a different species!" - Song Sparrow nests are very hard to locate. Using species that will use nest boxes (bluebirds, above) makes nest access much easier. Patty Gowaty's studies, like those of Mrs. Nice, focused on development and behavior. For population studies, banding young is often rather futile - many young die and few return in future years...

Mist Nets

    In Europe and Japan, long nets were developed to capture birds in warm and dry weather. A typical Japanese mist net (shown to the right) is about 10 m long and has a fine mesh (~3/4" for small birds, other mesh sized for larger species) suspended on five strong nylon strings ("trammels") with enough slack to form pockets or bags on each side. A path some 5 - 6 feet wide is cleared through vegetation, often perpendicular to a stream, road, dune, etc. Mist nets are then hung on poles (TV antenna masts) placed in holes in the ground bisecting the net lane. Note that the mesh is hard to see (right) and birds readily fly into it and become "bagged" in the loose mesh (below) Nets Net

Removing captured bird from a mist net.
  Song Sparrow Removing captured bird Catbird
    Song Sparrow, Melospiza melodia. Bird is trapped in a net pocket. Note strengthening trammel supporting the net.
Removing the bird - feed are freed first and the bird can then be pulled from the net.

Gray Catbird, Dumetella carolinensis. Helping with his removal.

    Bird in hand Savannah Sparrow Savannah Sparrow
    Savannah Sparrow, Passerculus sandwichensis. Held by Jack P HAilman (Wisconsin). By placing the neck between the first two fingers, the bird can be manipulated to make measurements, observe fat, and apply a band.
Applying the band.

Spreading the wing for measurements.

    White-throated Sparrow Woodcock Chat
    White-throated Sparrow, Zonotrichia leucophrys. White stripe morph. American Woodcock, Scolopax minor. A surprise in the net. Yellow-breasted Chat, Icteria virens. Banded and ready for release.
    Cannon Nets  

Large numbers of shorebirds ("waders") migrate along our coasts. They can be captured using mist nets (above) but care must be taken that netted individuals not drown if the nets are in wet areas and tidal excursions must be carefully projected for success. Some shorebirds are found in large, coordinated flocks - our Red Knot is one such that gathers along our shores. The wildlife staff and volunteers on Kiawah have initiated a program to band Red Knots using cannon nets...all images are property of the Kiawah Wildlife program (© Kiawah Island Bird Banding).
    Planning involves finding even dry beach (or exposed areas above low tide) where large groups gather. Prevailing wind direction may need to be considered in placing the net. Preparation involves placing the net and anchoring the back edge. The net is then folded along this line and attached weights on the leading line are inserted into "cannons" behind the net. The net is fired when the desired number are within the field and the pathway is free of birds/people that could be injured by the weights. After deployment, birds are removed as rapidly as possible to prevent injury and to give shelter from the sun - they are then processed (measured, weighed, tagged and released)...

    Net Waiting Net firing
    The net - a soft net is pulled over a feeding or resting group by attached weighted projectiles fired using explosives or rockets Birds are entangled in the net and removed for study and tagging. This image shows a net that has been fired. Birds are being extracted... Here investigators are waiting for birds to gather before firing the net. The net has been fired and is covering a group on the beach.
Knot Knot
Adult Red Knots Non-breeding knot
Banding Band
Measuring and tagging  
    Banner - US F&W band on a Gray Catbird leg.