Songbird Migration across the Gulf of Mexico

One of the best things about being a biologist is that “life” never ceases to amaze me.  Recently I had the opportunity to experience part of the spring migration of nearly a billion songbirds that occurs annually across the Gulf of Mexico.  I joined several remarkable bird photographers (including Alan Murphy and Brian Small) for 4 days in a photographic blind in Stevenson’s Woods on the west end of Galveston Island. Our objective was to photograph many of the 30+ species of Wood Warblers and many others of the 200+ species that migrate as a wave of nearly 1 billion birds across the nearly 700 mile span of the Gulf of Mexico.

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The Gulf Migration:

Each spring, one of the most spectacular migrations in the world occurs across the world’s largest Gulf – the Gulf of Mexico.  Over a 3-4 week period, nearly a billion birds including more than 200 species travel from their neotropical homes where they have spent months feeding, to North America where they will continue to feed and will nest and raise their chicks which will return in the fall with their parents to the tropics of Central and South America.   Migrating birds have two choices for their migratory route.  They can fly along the circum-Gulf route (yellow in diagram below) or they concentrate along the Yucatan Peninsula of Mexico and travel north along the shorter, nearly 700 mile trans-Gulf Route (red arrow)  – a non-stop trip across the open waters of the Gulf of Mexico.  A majority of the birds that make this trek elect the shorter open water direct route.
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Over the days before their spring migration north, hundreds of thousands of songbirds concentrate in areas near the tip of the Yucatan Peninsula.   They have prepared for this flight by eating a high carbohydrate diet that will provide them the energy for the 16-20 hour non-stop flight north.  As the sun sets and stars begin to appear, masses of birds ascend to the tops of trees awaiting the beginning of the flight.  As the stars brighten, the birds lift off and within 30 minutes, all begin their flight north, guided by the polarized light of the setting sun, star maps and the earth’s magnetic field.  Birds in the migration flock fly at an average speed of 30 mph and fly north throughout the night.  The radar images below show the arrival of Gulf migrants along the coasts of Louisiana (immediate below) and the coast of Texas (two following images).
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Radar image of songbird migration across the Gulf of Mexico, approaching Louisiana near Lake Charles, April 2009.

During this part of spring, winds generally push the north-flying mass of birds to west – generally bringing the birds to western Louisiana and Texas.  The first land that they encounter are the barrier islands of this coastline.  Galveston Island, one of the largest barrier island (27 miles in length) is an epicenter for the migration.
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Depending on weather and wind patterns, migrants generally do not stop in mass along the barrier islands.  Rather, many continue 30-40 miles inland where they first meet the southern edges of the North American deciduous forests.  Here they may find fresh water to drink, insects and other food items and shelter.  But some of the birds do stop along these islands and if one is lucky (and the birds are not), the migration may encounter a north wind/storm that will exhaust them during their night flight.  Survivors will literally “fall” from the sky along these islands in a phenomenon known as a migratory “fall-out”.    Probably thousands of birds are lost to sea during these difficult flights as many deceased birds are found along the shore and inland.

Stevenson Woods – Galveston Island

Thousands of songbirds stop off at Stevenson Woods, situated near  the western end of Galveston Island.  The property is owed by Jim Stevenson, an ornithologist and birding guide who has created an environment that is almost unique on the relatively barren Galveston Island.   Stevenson Woods is situated on a 14 foot hill that was made over 100 years ago to provide a hurricane refuge for cattle that otherwise would have drowned in the huge swells that can cover this part of Galveston Island during hurricanes.    The hummock is now covered with 100 year-old live oaks, old fruit trees, many native berries and other plants that provide food for visiting migrants.
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Galveston Island, Texas. Pin denotes site of Stevenson Woods. Most of the island is devoid of trees or standing fresh water.

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Stevenson Woods, Galveston Island. Pin indicates property. Notice that this grove of trees on a 14′ hummock is easily seen by birds approaching this island.

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Stevenson Woods, Galveston Island, Texas. The back bay water separating this barrier island from the mainland lies immediately behind the property.

Birds approaching Galveston Island are flying at an altitude of 1000-4000+ feet in a highly mixed flock.  The strong flyers such as the Chimney Swifts are the first to arrive in the morning followed shortly after by Hummingbirds.  This is usually around 9 -11 AM.  After this, the parade of songbirds follow led by strong-fliers such as thrushes, tanagers, and mockingbirds.  In the late morning and early afternoon, the Wood Warblers begin to arrive.  As birds arrive at Stevenson Woods, they  announce their arrival vocally as they literally drop vertically out of the sky – almost magically appearing on the branches of the woods.
Many of these birds are exhausted and seek out water before food.  Some fall asleep on the ground immediately upon landing.  By providing a simple shallow bird bath with a drip of water to attract the birds, hundreds of birds were lured to photogenic branches that we had set up for them to land on before and after their baths. This means of attracting birds was particularly effective on warm afternoons (see
for reference in setting up this bird attractant).
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Low platform bird bath provides a place for birds to drink and refresh by bathing. A drip line slowly dripped water into the shallow pond to attract birds. Simple tripods were used to hold branches for landing perches for the birds.

By late in the day, few birds remain in Stevenson Woods.  After resting, feeding and drinking, they returned to the sky flying north to the North American deciduous forest destinations.  As they continued their journey north, we all spent the night downloading and processing images and preparing for the next wave to arrive at our watering hole the following day.

Here are a few of the birds that dropped in to have their picture taken.  Most of the Wood Warblers (18 species) were photographed in a single day – following a night of north winds that slowed the migration and caused a “fall out” over this area of Texas.  Go to the Bird Taxonomy Gallery to see more pictures of these and other species.  Please note that images are copyright protected
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Acadian Warbler #15. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

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Eastern Wood Pewee #2. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

Eastern-Kingbird-3

Eastern Kingbird #3. Stevenson Woods, Galveston Island. Part of  migratory flock “fall-out”. April, 2013.

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Philadelphia Vireo #7. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

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Warbling Vireo  #4. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

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Yellow-throated #1. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

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Swainson’s Thrush #2. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

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Gray-cheeked Thrush #11. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

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Gray Catbird #8. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

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Northern Mockingbird #1. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

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Cedar Waxwing #5. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Northern Parula #1. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Yellow Warbler #43. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Yellow Warbler #45. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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American Redstart #3. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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American Redstart #22. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Blue-winged Warbler #7. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Golden-winged Warbler #3. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

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Magnolia Warbler #2. Stevenson Woods, Galveston Island. Part of large migratory “fall-out”. April, 2013.

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Chestnut-sided Warbler #4. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Black-throated Green Warbler #1. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Blackburnian Warbler #11. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Worm-eating Warbler #10. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Ovenbird #2. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Northern Watherthrush #9. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Kentucky Warbler #5. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Kentucky Warbler #8. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Yellow-billed Cuckoo #6. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Yellow-breasted Chat #3. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Summer Tanager #7. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Summer Tanager #23. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Scarlet Tanager #4. Male. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Scarlet tanager #8. Male. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Blue Grosbeak #1. Male. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Indigo Bunting #37. Male. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Northern Cardinal #204. Female. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Northern Cardinal #201. Male. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Painted Bunting #33. Female. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Painted Bunting #27. Male. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Rose-breasted Grosbeak #88. Male. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Baltimore Oriole #42. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Bronzed Cowbird #1. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Eastern Meadowlark #3. Stevenson Woods, Galveston Island. April, 2013.

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Orchard Oriole #20. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

First spring male

Orchard Oriole #19. First spring male. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

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Orchard Oriole #44-2. Female in peach tree. Stevenson Woods, Galveston Island. Part of spring migratory “fall-out”. April, 2013.

Thanks for reading this blog.  I hope some of you may someday experience the wonder of this migration and meet some of its members in person!  Happy birding. 
– Lynda J. Goff
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