The Mockingbird Problem

We’re back from a birding/fly-fishing trip and will now finally address The Mockingbird Problem. Northern Mockingbirds – and about twenty percent of other passerine songbirds – are mimics. They steal their songs from their environments. Imagine the smartest student in class unnecessarily cheating on tests by going around the room and copying little bits of every other student’s answers.

That makes no sense. Instead of getting an “A” on the test, the student would get an “F” because her answers would be gibberish. Yet mockingbirds – obviously the star students in avian music class – do precisely that. Rather than develop their own unique songs, they just copy bits and pieces of the songs of other species.

Why?

Wouldn’t it be easier and less costly to invent their own songs and pass those down to their offspring? Less brain power would be required and learning would be simpler. Besides, the mockingbird isn’t fooling any other birds. They all recognize that the mockingbird isn’t one of them.

Nobody knows. We think we know that they sing for the same reasons as other birds: the males are seeking, stimulating, and keeping mates and they are competing with one another for mates and territories. But no one knows why they evolved singing songs of other birds. The same question can be asked about other mimics such as Common Starlings, Marsh Warblers, Australian Lyrebirds, bowerbirds, scrubbirds, and African Robin-chats.

Chihuahan Desert Mockingbird Locale (Otero Mesa)

We’ve learned a lot about Mockingbird song in the last century though. We know, for instance, that both males and females sing, although females sing only in the summer and only when their mate is off their territory. The males sing most in Spring, less in summer, still less in Autumn and hardly at all in winter. Unmated males sing more than mated males and will, in spring, sing all night long. (I’ve camped on the Chihuahuan Desert and listened to one sing all night long. That mockingbird may have been lonely, but he provided me with one of my favorite backpacking memories.) Unmated males sing in all directions, while mated males tend to sing inward toward their own territories.

Darwin's Mockingbirds

The males possess two entirely different repertoires, one for the spring and another for autumn. One had 203 songs in his mind. Somewhere between 90 and 150 seems about average. They continue to learn new songs for as long as they live. Older birds have larger repertoires than younger ones. Males with the most varied songs may get the largest territories. They may also mate earlier. And they sing all the time during breeding season, warbling away while copulating, eating, and foraging.

And probably they sing silently while dreaming. We know that Zebra Finches dream in song; no reason to suspect a bird that devotes as much of its cranial capacity to learning and remembering complex songs wouldn’t also dream in song.

They sing more during full moons.

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For more on Northern Mockingbird song see:

Derrickson, K. C. and R. Breitwisch. 1992. Northern Mockingbird (Mimus polyglottos), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/007

doi:10.2173/bna.7 (Subscription Required)

Frank Gill, Ornithology (3^rd ed.), pp 230-231 and 237.

For a sample song, try this: http://www.birdjam.com/birdsong.php?id=4

The photo of the Northern Mockingbird at the top is by Manjithkaina, used via a Creative Commons license.

Birds and the Law

Birds are seldom in lawsuits.  Like trees and other manifestations of Nature, they are not allowed into our courtrooms.  Mostly this is the result of the mental divide in our culture between “us” and “them”; between humans and the rest of the world.  This humanoid illusion of separateness prevents our legal system from paying much attention to birds, except occasionally as metaphors.

But sometimes a bird can be a key part of a lawsuit.  So it was recently with the Northern Aplomado Falcon.

Our First Aplomado

The northern Chihuahuan Desert reaches into southern Texas and New Mexico.  One of the largest remaining, and relatively undisturbed, tracts of Chihuahuan land sits in the southern-most part of New Mexico and is known as Otero Mesa.  Today, thanks to the courage and stubbornness of cattle ranchers, it is mostly over-grazed scrubland; but, if humans would ignore it long enough, it would return to those thrilling days of yesteryear when it was a rich diverse desert.  And the perfect home for the Aplomado Falcon.

But underneath it lie pockets of natural gas which a human wants to drill and sell. He is a well-connected human too.  He is the Chairman of the New Mexico Republican Party.  In the past, Steven Griles, former number 2 man at the Department of the Interior and associate of Jack Abramoff, was his lobbyist.  (That was before Griles pleaded guilty to obstruction of justice and went to prison for lying about his conduct while at Interior.) The Department of Interior operates the Bureau of Land Management (BLM), which manages Otero Mesa and which granted the human drilling rights during the Bush Administration — while Griles worked at Interior and was doing favors for energy companies that contributed to Abramoff’s operations.  I don’t know if the drilling company on Otero Mesa made such contributions or not, but it got the permit from BLM anyway.

Otero Mesa

That decision landed the BLM in court.  Environmental groups sued, as did the State of New Mexico.  (Although it is a desert, a huge aquifer of drinkable water flows deep underneath Otero Mesa and natural gas and oil drilling operations can pollute underground water. New Mexico doesn’t have much water, so it tries to protect what it does have.  Besides, the well-connected oilman who got the permit to drill is a Republican and New Mexico’s governor was a Democrat.  Not that politics ever enters into land use decisions.)

A part of the lawsuit swirled around Northern Aplomado Falcons.  Northern Aplomados are an endangered species.  They live nowhere in the world except Chihuahuan Desert grassland.  Their habitat, both in the United States and Mexico has been carved up for the benefit of the human species with no regard for the bird.  Not long ago the only place in the United States where you had any chance at all of seeing one was the Laguna Atascosa Wildlife Refuge in South Texas where they were introduced in the 1980s.

Because the falcons are an endangered species, the job of protecting them in the United States falls to the Fish and Wildlife Service (FWS), another agency of the Department of Interior.  In Jume, 2003, the BLM concluded that allowing gas drilling on Otero Mesa would adversely affect the falcons.  That meant it had to bring in the FWS for a lengthy consultation process that might result in a conclusion that the drilling should not happen.  Three months later, BLM reversed itself and decided that drilling would not hurt the falcons. That same decision also doubled, to 600,000 acres, the land available for drilling.  Mr. Griles was still number two at Interior.  (He resigned on December 7, 2004. After that he returned to lobbying until early 2007.)

In 2006, the FWS decided to attempt reintroducing the falcon to Otero Mesa and changed the bird’s status from “endangered” to “experimental.”  That decision effectively ended the environmentalists claim that BLM illegally ignored the falcon when it granted the drilling permits.  (Another lawsuit is pending about that decision.)[1]

A Reintroduced Juvenile Aplomado Meets Raven

But, on the other hand, the FWS gave The Peregrine Fund almost $300,000 to attempt to bring the Northern Aplomado back.  As of this writing about 100 have been reintroduced and at least 50 have achieved independence and may reproduce.

Last month the federal Tenth Circuit Court of Appeals ruled that the BLM acted illegally when it approved the drilling. Now, the agency must start over and comply with environmental laws if it wants to approve drilling on Otero Mesa.

It’s a double win for the Northern Aplomado Falcons; 100 more of them now live on the mesa or in its vicinity and — for the moment, at least — nobody is drilling for natural gas or oil.

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[1] Forgive me a personal aside. Some years ago, before the reintroduction program started, I traveled with a backpacking buddy to Otero Mesa. At that time, I had never seen an Aplomado. Before we went, we stopped by the local BLM office to get a map and talk with the BLM officer overseeing Otero Mesa. He was friendly and helpful as he showed us the places where we were allowed to camp and which roads were passable and which not. (Otero Mesa is largely roadless but is intersected by a few dirt roads.) He became much less helpful when I told him that I wanted to see an Aplomado. In fact, it was only in the face of my withering cross-examination that he even conceded one had been seen on the mesa. Finally he waved his finger at the map and said, “Maybe there.” I promised to call if we saw one. We didn’t. I suspected then and still suspect, that sightings of an endangered species were complicating the gas drilling lease.

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You can read the unanimous opinion of the Court here. Interestingly, the three judge panel consisted of one judge appointed by President Reagan, one by President Clinton and one by President George W.Bush.  The BLM, the wannabe driller, or the petroleum industry can ask the full court to hear the case and it also can petition the Supreme Court to hear it.

You can read more about the falcon and the experimental reintroduction program at this link:

“Aplomado Falcon Reintroductions”