Dear Bird Folks:

Last week I had both orioles and hummingbirds still coming to my feeders. Suddenly, I don’t see either one. Do you think that it is the threat of this hurricane that has made both birds leave so quickly? Also, I’m worried what this big storm will do to all of the birds that are moving south this time of year. Are they in trouble?

-Joyce, Barnstable

You’re Sweet Joyce,

With everyone running around buying batteries, masking tape and bottled water in preparation for this storm, you are thoughtful to be worrying about the birds. And you should be worried; hurricanes can be tough on just about everything in their path. Hummingbirds and orioles are no match for a storm that can flatten full-sized buildings.

However, the reason that your hummingbird’s and orioles have moved on has nothing to do with the weather report. Unless you are one of those people who watch TV and the Weather Channel real loud, the birds in your yard have no idea about any big storm coming. Yes, birds are sensitive to certain climatic changes, but right now the storm that you and everyone else is worried about is several hundred miles away. Only people and creatures that have expanded basic cable have knowledge about this storm.

Your hummers and orioles have left because it’s time for them to go. Even though the Cape is still warm, there is plenty of food around and most of the traffic has thinned out, they must leave. Central America is where these birds call home in the off-season, and there is no way they want to experience a New England winter like last year.

Many environmental clues tell migrating birds that it’s time to head south, but by far the most important clue is the length of day. As the hours of daylight get shorter, the birds know that it’s time to pack up and go. In fact, you might not realize it, but “your” hummingbirds and orioles have probably moved out weeks ago. The birds that have been at your feeders recently are more than likely birds that were hatched out up in northern New England or Canada. They are using your feeders as a refueling stop on the long trip south.

As noted above, birds can sense climatic changes. After refueling they wait for favorable weather conditions. Most like to ride the leading edge of cold fronts, which often provide the proper tail winds needed for long flights. Moving fronts at night are especially beneficial to songbirds. Night time air is often less turbulent than air that has been heated up by the sun. That is why your birds seem to be here one day and gone the next, because that is exactly what happens.

Hurricanes or any kind of bad weather do cause big problems for migrating birds. Birds that are flying over land can settle down and ride out the storm huddled up, but birds caught over open ocean are in big trouble. If they are unable to fly above or around the storm, they will soon become exhausted and headed for a date with Sponge Bob.

Although it is sad to think about birds being lost at sea, it’s important to remember that not all birds migrate at the same time. Any given storm will only stop a small percentage of migrating birds. The real problem with hurricanes is the damage they cause to environmentally sensitive areas. Tidal surges wash over barrier beaches that can take years to recover. Flooding rains can dilute brackish marshes, wiping out critical feeding areas. And the wind damage to trees, shrubs and other vegetation can eliminate thousands of acres of nesting habitat.

It’s kind of creepy writing about big storms with Isabel, a category four hurricane, bearing down on this part of the world. By the time you read this we’ll probably know just how bad Isabel turned out to be. Hopefully we’ll all be okay.

I’m glad you are concerned about the birds’ safety Joyce. I’d write more about this subject but I need to run out for some batteries, masking tape and bottled water.