Monday May 14, 2012

Q:The grosbeaks came back a few days ago. I was wondering why they are such late arrivals but couldn't find an explanation in National Geographoc or Stokes so went to Wikipedia. It didn't explain much except that early May is normal for a return to the Northeast. Is it their food source that doesn't develop here until May (bugs, berries, tree buds etc.)? Or is it still really easy pickings for food down south? Wikipedia also said they are migrating north later and later. Given global warming, shouldn't that trend be the other way? Or should I just consider the source and discount it? What websites do you recommend so I don't have to bug you?

A: Where would this column be if readers did not ask questions?

It does not "bug me," but rather keeps me in business.

Printed pages, including local bird records, usually provide me with most of the information I need.

When those sources fail me, I phone my good friend Dave St. James.

When I search on-line, I most often check the Patuxent Wildlife Research Center (www.mbrpwrc. usgs.gov/infocenter) or for basic information, the Cornell website (www.allaboutbirds.org).

Some of our "summer birds" do not arrive until mid-month, so the first week of May is not especially late.

When considering the arrival date of a species in a given area, I think Grosbeaks that it is important to use the median arrival date over a number of years when possible.

Locally, some arrival dates gleaned from material in my library follows: In 1900, Faxon and Hoffman (The Birds of Berkshire County, Massachusetts) give "about May 10" as the arrival date for the RBG.

In 1955 (Birds of Massachusetts) Bailey reports "...May 8 to 10 that a widespread arrival is recorded) In 1999, Hendricks (Birds of Berkshire County) lists May 3.

Apparently, back in 1945, we may have experienced a warmer than normal period, similar to this year, when many species arrived abnormally early, " with the RBG first seen on March 29."

This species feeds primarily on insects, but also on buds, fruits, seeds and flowers. So on years with more available food along the migration route, it would seem reasonable that birds would arrive earlier, not later. I welcome an explanation of later average arrival if that be the case.

And keep in mind, more than a full belly drive birds north.

NEWS FROM A READER: It's time to put out the oriole and humming bird feeders.

I put my oriole feeder out May.

Both an oriole and a hummingbird showed up today, Friday May 4.

Ray M., Hinsdale

HUMMINGBIRD FOOD, by the way, is one part granulated white sugar to four parts water. Red coloring NOT needed. Baltimore oriole food can be the sugar water mix or better yet an orange cut in half with fastened to any surface in the open where it may be spotted.

Questions and comments for Thom Smith: Email: Naturewatch@live.com,