Friday, November 11, 2011

Bird Specimens

Studying birds does not solely consist of looking at them in the field or in cages in a lab, much science occurs deep in the bowels of museums in cabinets containing thousands of dead birds. The logical next question is: how does one go about storing a bird for posterity?

Grassland Yellow-finch (male), Nov 9, 2011
Carefully (the obvious answer, right?). You make a study skin, pictured above. Now, of course, there is an art to this process that I have not mastered - mine look decent, not great, and I take forever and a day to create one - I have heard that good ornithologists view the seven-minute-skin as the mark to aspire to, whereas an hour is what I generally shoot for. Basically, to make a skin, you take out all the guts, fill the bird with cotton and sew it back up. Simple as that.

Dorsal view, same specimen, thread temporarily on to hold wings in place while it dries

I was shown the ropes this past summer by a very experienced (and most importantly, very patient) coworker at the Maria Mitchell Association, Julia, who has prepared hundreds of these and who makes them all look perfect without seeming to try and generally doing two while I bumble through one mediocre attempt. So without further ado: beginning your bird. The first thing you must do, while the bird is still whole, is take measurements. Wing chord, total length, tail length and bill length are fairly normal ones, though a whole host of others could be taken, too. Take the mass and assess the molt on flight feathers, tail and body feathers.

A Chucao, thawed, ready for stuffing!

The pictures I will include from here on are of a Chucao Tapaculo, a really cool antbird. At Senda Darwin, they want to begin a collection, as they have a freezerful of birds and mammals, but no one here knows how to do it. So despite my own inexperience, I am the teacher here (and I don't speak the language well!). I prepared the finch pictured previously to show how to do it and Gabby, a veterinarian here, prepared the Chucao. This particular bird was really ratty, it is in severe molt (and molting feathers fall out really easily) and had been frozen awhile and may have beat itself up in the trap, but despite this, Gabby did a good job with it.

Molt. Notice the sheathing on the outer pirmaries (and the secondaries). Also
notice the tiny wings that this bird has for its size. 

After measurements, you must take out all the insides. This involves cutting down the sternum and peeling back the skin from the muscle. Then you must cut bones at the hips and the shoulders in order to pop the body out, which basically inverts the skin at the neck. You can then peel back the neck all the way to the back of the head and pull out the tongue. After which you cut off the back of the skull and remove the brain.

All the insides of the bird from the tail to the base of the skull (neck at right). 
Neck skin inverted, back of skull cut off, ready to take out the brain!

Fill the eyesockets in with cotton and pull the skull back through the skin (it was inside out!). Then you have a skin without any meat on it, which you can stuff with cotton and sew up.

The yellow-finch with cotton eyes. When I showed specimens to kids last summer,
they all wanted to know where the eyeballs went.  

Sounds easy, doesn't it? It isn't, but much can be learned from dead birds, and now, unlike in times past, most specimens are salvaged - from window strikes, car hits or cat kills. The Chucao died in a trap set for monitos (an rare marsupial) and the yellow-finch was found with a broken leg, bleeding, on the ground near one of the swallow nest boxes and died while I was bringing it back to the center.

You have always wondered what bird eyeballs look like, right? Blueberries.

When you are done, a specimen with proper curation should last for hundreds of years (though mine are not of that quality, surely).

Finished, pre-drying, Chauco Tapaculo - the molt made it very ratty  even before
the loss of some feathers during prep - but a damn good first specimen for Gabby.

1 comment:

  1. Nice job! I agree, the Chauco specimen is excellent for a first bird. Nothing like my catbird dart. All it takes is practice and patience. I fully expect you to be way better than me at preparing mammals when you return.