Here’s the Central Texas bird forecast for the month, courtesy of Travis Audubon. Learn more about Central Texas birds and bird-related events for all ages at travisaudubon.org or by calling 512-300-BIRD. Follow us on Facebook.
What to watch for in September: Return of the Osprey
The Osprey is a large charismatic raptor primarily seen from September through April in Austin. In the summer, most breeding Ospreys can be found in the northern U.S., Canada and Alaska. Then in the fall, they move south, with some wintering in Texas but even more moving down into Mexico, Central America and South America for the winter.
Why are there summer sightings in Austin? With the distances many of these birds travel and the demands of migration, some birds may become unfit along the way, others lost, and others delayed by weather. Some are juvenile birds that are staying on their wintering grounds here for 18 months to mature, before heading north to breed in their second spring. Some might be adult females. They start migrating south in August, a month or so before adult males, which have been observed on the breeding grounds continuing to feed young that are not quite independent.
Fun facts about Osprey migration
Many Osprey make long distance migrations, even over open water like the Caribbean Sea. The Osprey can live 15-20 years. Those from the northern part of the breeding range that winter south of the equator log a lot of air miles on those wings—at least 124,000 miles over a lifetime.
Lightweight satellite transmitter backpacks on Ospreys are giving scientists a better understanding of migration routes, timing and distance traveled. As an example, in 2008, a tagged three-month old Osprey flew from Martha’s Vineyard to French Guiana in South America, a distance of 2700 miles, in 13 days.
Migrating Ospreys, unlike some raptors like Swainson’s Hawks and Broad-winged Hawks, are generally solitary on migration. Breeding pairs don’t migrate together, nor do they migrate with their young. They don’t necessarily overwinter in the same areas. According to Birds of the World, all North American breeders are faithful to their overwintering areas.
Osprey identification
One major tip for Osprey identification is its choice of habitat. It’s tied to the water since 99% of its diet is fish. If you see a large bird flying or perched along a body of water, whether a slow moving river, lake or Gulf bayside lagoon, take a second look. The Osprey is much smaller than a Bald Eagle, another possible fish-loving contender here mainly in winter.
The Osprey has a mostly white head but with a bold brown eye stripe that runs back from its eye, unlike the adult Bald Eagle’s all white head. When seen from below the Osprey has white underparts from neck to feet, compared to the adult eagle’s brown. In flight its wing shape is narrow, in contrast to the broad wings of the eagle. If you see an all-white tail from above or below it’s an adult Bald Eagle.
The Osprey often appears to be flying with wings shaped like an M, compared to the eagle’s flat-winged look. It has a wingspan of about 63 inches compared to a Bald Eagle’s 80 inches, and weighs about a third of a Bald Eagle’s 9.9 pounds. If you see two birds tussling for a fish that one of them has caught, chances are the eagle is trying to steal the Osprey’s prey. The eagle usually wins.
Osprey behavior is fun to watch
The Osprey is a skilled angler. It likes to course over clear water looking for movement below the surface. Once it spots a fish it will hover and drop down with legs extended to hit the surface feet first, sometimes fully submerging. Then it takes off with strong wingbeats, shaking the water out of its wings as it flies, like a dog shaking its fur after a swim.
If successful, with its unusual reversible outer toe it manipulates the fish so that its head faces forward for less wind resistance. The fish is then held with two toes forward and two back. On top of that the Osprey has rear facing barbs on the soles of its feet for a better grip. It will often take its prey to a high flat-topped pole to eat it. Another fishing strategy the Osprey uses is to fly close to the water dragging its feet to spook fish up. They also will fish from a perch. A typical fish weighs 5 to 11 ounces, and is about 10 to 14 inches long.
The Osprey is very vocal. You may hear it before you see it. The most common short call heard in Austin is a “tew” which may indicate that the bird is alert or excited.
It’s not easy being an Osprey
Osprey numbers declined significantly in the 1950s due to DDT, a pesticide used to kill insects that then accumulated in Ospreys and other fish-eating birds like Bald Eagles. Its effect was to weaken egg shells so nesting success was significantly reduced. Once DDT was banned, numbers began to rebound.
Artificial nest platforms attracted birds to areas where they had disappeared. Ospreys have shown a preference for these platforms, and are tolerant of human activity around them. There are still risks to Ospreys’ continued survival like shooting, electrocution on perches, predators like coyotes getting introduced to previously predator-free islands where they impact ground-nesting Ospreys, and declining fish abundance for their offspring.
Where to see an Osprey in Austin?
Take a walk along Lady Bird Lake, visit the Colorado River at Hornsby Bend Bird Observatory, try the Roy Guerrero Colorado River Overlook by the playground, visit Lake Travis’ Windy Point or walk down by the river at Commons Ford Ranch Metro Park or Emma Long Park. Look for them flying or on a high perch like a radio tower. Celebrate this cosmopolitan species that can be seen on all continents except Antarctica!
Upcoming Travis Audubon events
Cooler weather is on the horizon. Check the events calendar for field trips and classes. New to birding? Try a beginner’s bird walk such as the ones frequently offered at Commons Ford Ranch Metro Park.
Events fill quickly, and registration is required for most. A free fun night’s out to see Chimney Swifts staging before they head down to South America occurs on Sept. 12. It’s experiential birding at its finest!
Compiled by Jane Tillman, Travis Audubon volunteer
Resources: All About Birds, Birds of the World, Handbook of Texas Birds, 2nd Edition by Lockwood and Freeman, the Travis Audubon Seasonal Distribution Checklist, The Sibley Guide to Birds by David Sibley and Peterson Field Guide to Bird Sounds of Eastern North America by Nathan Pieplow.
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