Saturday, March 21, 2009

Wooing Mrs. Nuthatch

Bird watching can be a lot more than just identifying what shows up in the yard. A good bird watcher also notices what the birds are doing.

Nine-year-old Blythe Filaski of Ridgefield is a good bird watcher. “Recently, I spotted two nuthatches on my pear tree,” Blythe writes. “The nuthatches must have been mates, because their bills were together, almost as if they were kissing. I think they were sharing seed.”

Blythe was lucky enough to observe an interesting courtship behavior of the White-breasted Nuthatch. Here is how Arthur C. Bent described a pair of nuthatches 60 years ago:

“All through the winter the pair has lived not far apart, feeding within hearing of each other, but the male has paid little attention to his mate; in fact, on the food shelf, he has shown dominance over her; but now in the lengthening, warmer days of spring, he becomes actively engaged over her comfort.

“A real courtship begins: He carries food to her and places it in her bill, he stores bits of nut in crevices of bark for her convenience, and he often addresses his singing directly to her. Standing back to her, he bows slowly downward as he sings, then in the interval before another song he straightens up, then bows as he sings again. The songs come with perfect regularity over and over again and can thus be recognized even in the distance as the courtship song.”

Ornithologists have been fascinated by this behavior in many species, including cardinals and hawks. Of course, on the simplest level, it can be taken as a way of wooing a mate by making her happy – just as men often take women out to dinner on dates.

However, scientists see more in the behavior. The food exchange not only develops pair bonding, but may also help convince the female that her mate will be a good provider during the forthcoming nesting period.

“Increasing evidence suggests that females who receive more food from their mates lay larger clutches” of eggs, wrote David W. Winkler, in Handbook of Bird Biology (Cornell Lab of Ornithology, 2004). “Mate feeding probably makes it possible for a female to raise more young, by keeping her in good condition and allowing her to put more energy into feeding the young.”

In other words, a nice dinner now may mean more and healthier kids later.
So, for the nuthatch and many other species, “the way to a woman’s heart is through her stomach.”

1 comment:

NiƱo Miguel said...

it's very nice to know that there are people appreciating the nature especially birds.