Migration
Where Have All the Robins Gone?
Q. What happened to all the robins? I’m not seeing them any more.
A.
Each year in late summer and fall, robins leave the territories where
they’ve raised their young. They spend fall and winter in flocks,
traveling to places where they can find more food. In fall, we receive
questions from people in some areas who are wondering where the robins
have gone, and questions from people elsewhere who are incredulous
because they’ve been inundated with large flocks of robins.
By
flocking, the robins benefit by having more eyes to look out for
predators and to find food. You probably won’t see individual robins
again until spring when the demands of finding and defending a
territory cause them to leave the flock and strike out on their own.
Although
robins are one of the most familiar and widespread birds in North
America, their patterns of movement are poorly understood. In fall,
their migrations are often influenced by the availability of fruit, but
in spring they move in response to the availability of soil
invertebrates, such as earthworms. Their numbers in particular places
may vary from year to year.
Robin sightings reported by
participants of the Great Backyard Bird Count show that robins tend to
avoid areas with deep snow cover. This makes sense, since they often
search for food in the soil. You can read more about these results on
the Great Backyard Bird Count web site.
You
can help scientists document the seasonal movements of robins by
participating in the Great Backyard Bird Count in February or by
reporting your sightings to eBird.
This online checklist program allows you to keep track of your own bird
lists, see the changes in numbers throughout the year, and explore maps
showing where else the birds are being seen.
For more information about robins, including a map showing their summer and winter ranges, visit our Online Bird Guide.
Hungry Hummers?
Q. I have been told that I should stop
feeding hummingbirds in the fall so that they can begin their southern
migration. Is this correct?
A. That's actually a myth. A number of factors trigger the urge for
birds to migrate, but the most significant one is day length. When the
days get shorter, the hummingbirds will move on, regardless of whether
there are still filled feeders available for them.
We do,
however, encourage people to keep their hummingbird feeders full for
several weeks after they have seen the last hummer just in case there
are stragglers in need of additional energy before they complete their
long journey south.
Learn more about feeding hummingbirds by visiting our pages on feeding and attracting birds.
Birds and Hurricanes
Q. How do hurricanes
affect migrating birds, and is there anything we can do to help the
birds that have been negatively affected?
A. Each
year, migratory birds cross the Gulf of Mexico during the hurricane
season. Birds wait for favorable winds and weather before taking
flight, so they won’t try to fly during a hurricane. If a migrant lands
at a spot that has been devastated by storms, it will continue onward
in search of better stopover areas.
Unfortunately, sometimes
migratory birds get caught in bad weather while crossing open water.
Although migrants have enough fat (fuel reserves) to make the 600-mile
Gulf crossing in favorable winds, they may not have enough energy to
survive if they have to fight against headwinds. Preserving critical
coastal habitats is important for exhausted migrants.
Resident
birds in hurricane areas also suffer when their food supplies, such as
fruits and berries, are stripped from trees and shrubs.
Birds
and hurricanes have coexisted for millennia, and given the chance,
healthy bird populations can rebound from the effects of natural
disasters. Unfortunately, humans are making this difficult for some
birds because we have destroyed so much of their original habitats.
With fewer birds and fewer places where they can live, hurricanes pose
greater threats to vulnerable bird populations. For this reason, one of
the best things we can do to protect birds from hurricanes is work to
ensure that there are enough birds and places for them so they have the
opportunity to rebound.
Homing Instinct
Q: I have a hunch that the bird singing outside my window is the same one who nested here last year. Could that be true?
A: Possibly. Many migratory songbirds return to the same territory or local area each spring after traveling thousands of miles to and from their wintering grounds. Migratory songbirds tend to have short lives (annual mortality rates are about 50 percent), so some of the birds in your yard each year are probably newcomers. Studies of banded birds show that 20-60 percent of migratory songbirds typically return to the same local area.