Tuesday, March 26, 2013

Love Among the Nuthatches



The little drama below was photographed by Lisa Culp on March 24, 2013 in Somme Prairie Grove.

Many people don’t even notice them, even though you can find nuthatches year round in every good Illinois woods.  Only occasionally perching on a branch, they mostly hug tree trunks and limbs. That’s their niche; they hunt bugs and bug eggs in the tree bark.

But when it comes to love, among the nuthatches it's truly a many-splendored thing. The male is a handsome devil, with a beady eye, black cap, and elegant blue-gray, black, and white design. (You can't see his fetching chestnut under tail coverts until he's ready to flaunt them.) 


Lisa's camera was following a demure female, with a gray cap and generally more restrained 
and subtle style. Suddenly, out of nowhere, she (the person) noticed that she (bird) had company. 

Indeed, our little female stopped looking at Lisa and started looking at Mr. Big Stuff. 
It turned out that he'd arrived with a bug. 


Mrs. Hatch opens her bill with a begging gesture. That's how she indicates she's decided
 to give the guy a try. As you can see, this gesture makes him hopping excited. A courtship 
is under way, and she is saying, "Yes - yes - feed me."                                                                                                                                                                                

Now comes the nuthatch version of kissing. They are both holding the bug. 
Their bills are together in a very intimate moment. My apologies to any sensitive viewers 
for whom this may be too much. (Even more exciting, you get a hint 
of those chestnut under tail coverts. Okay, it's not much of a view, and she can't seem them at all. They must fit in to some other stage of the courtship. But there they are.)

He hands off the bug. Be my mate. He's so strong and generous. Or is he?

He flies off to find more presents. She will eat the moth in peace and happiness. 

Yes, he's proving himself to be a good provider. But generous? Research on other birds shows that a well-fed female will lay more eggs (containing her, and his, genes). So, for the male, it's not all generosity. Perhaps he's expressing love. But it benefits him too. At least he'll help her feed the chicks, which is more than the bird males of some other species do. 

Notes:

1. She will lay between 3 to 11 eggs in a hole in a tree. They'll both feed the chicks insects and spiders. In winter they also eat acorns that they "hatch" out of their shells by wedging them in a tree crevice and whacking them with their bills. 

2. They do best among mature trees with a lot of old dead limbs. Please don't cut down the dead and dying trees in places where you want nature. So many species depend on them.

3. The research on increased egg laying with males feeding females was conducted on terns (which have to be light to effectively dive for fish). The female when she's ready to lay eggs weighs 50% more than when she's not breeding. In fact, she stops feeding herself entirely; she's just too fat. According to the Birder's Handbook by Paul Ehrlich et. al., "when a male warbler, crossbill, chickadee, or tern is seen feeding a female, it seems apparent that he is increasing his own reproductive success by keeping her fat and healthy." Inspiring, isn't it?

4. Nuthatches often fly high into a tree and then descend down the trunk head first, hopping, using their feet more than their wings. No other bird does that. Creative.

5. According to Ehrlich, "Courting male carries food to female, performs bowing and singing ritual with head feathers raised, tail spread." According to Richard Pough in the Audubon Land Bird Guide, nuthatches often mate for life.   

5 comments:

Anonymous said...

Stephen,

I enjoyed your blog post. Especially, how it shows the bond between the two nuthatches.

I was also happy to hear you tell readers that dead trees should be left for wildlife. Even when a dead tree is a safety concern, I believe a large portion of the trunk of many species, like oaks, can be left as wildlife habitat. As long as the limbs and tall trunk portions are removed then the potential safety concern should be mitigated.

Reading this post did make me think about how many stewards are cutting down black cherry trees. Black cherry is a host for many species of moths and butterflies. Some insects that use black cherry as a host are certainly feed to your nuthatches. Could you please explain when it is necessary to remove black cherry trees and when it is best to leave them.

Sincerely,

James

Stephen Packard said...

James, thanks for the good comments. I surely agree that too many beautiful old dead trees get cut down for "neatness." Some old-timers call them "wildlife trees" and rightly so.
You make an especially creative point when you propose that when a dead tree has to be cut for safety near a trail, perhaps part of it could be left in many cases.
As for the wild black cherry, it supports the red-spotted purple, one of the most dramatic butterflies of the savanna. But the "Woods Audit" showed black cherry as the major canopy invader of the oak woods. Yes, leave one here and there, but most of them have to go (along with most red oaks and maples etc. etc. if the oak woods are to be rescued from the edge of oblivion. By the way, wild plum supports many of the same species, and plums increase dramatically when the shade is reduced.

Good Oak said...

Steve, Thanks for the phrase "canopy invaders"! I'm going to use that one. Its much easier than saying 'fire-intolerant, shade-tolerant mesophytic tree species'.

I think this basic topic too many trees and the wrong trees being unhealthy for a woodland would be a great topic for an upcoming blog post. Its a critical issue and something that is difficult for the general public to get their heads around.

Stephen Packard said...

Good Oak, thanks for the perceptive thoughts.

I agree that it's a critical challenge to get enough people to understand that (in the absence of fire) too many trees can wreck the ecology of a forest.

The lack of adequate words and images is the big problem, oddly enough. There is plenty of good will, and there are plenty of resources to save the oak ecosystems. But, so far, our culture mostly hasn't made that decision. A political or educational failure. Something for us to keep working on.

Rob Liva said...

A noteworthy discussion here... hrm.

Cherry trees while a shade-tolerant canopy invader in oak systems, provide important habitat for lower foodweb critters like insects and spiders.

Wild plum an associate species in the same systems, a shrub tree which harbors similar faunal associates as cherry, but becomes more common in more open canopy woods.

thanks,
R