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Mexico Part 2 – Desert Banding

Once I’ve found a routine for early mornings, I happily adhere to them, especially to see some birds close!  Bird banding dictates early mornings for several reasons.  Birds are more active on cool mornings in hot clines.  Setting up nets at daybreak means birds don’t see nets being set up by loud clumsy apes and can avoid them. Finally banding birds in the heat of the day is dangerous for them because they are put in a stressful situation without food or water.  This final reason is the calculated risk taken to gather important data and responsible banders will cancel readily.

Our first foggy morning the crew was supposed to be out netting birds near the road into Navopatia.  But heavy fog soddens nets, which will soak birds.  Deserts aren’t even vaguely warm before the sun is of sufficient height and this combination can kill.  Nothing makes a bander more upset than losing birds unnecessarily (except maybe cows walking through your expensive mist nets).  Life is always in the balance and I’m not unduly sentimental about natural death.  But being the hand that dealt or even a part of any operation where a mistake happens (this is very rare) is devastating.

Some people might have objections to handling birds, suggesting that it’s an unnecessary stress on birds and that we can learn through passive observation.  While I agree there is still plenty of extrapolation from point counts and area searches to be had, banding provides a massively in-depth look into the life of birds and accurate population samples.  According to USGS and the National Bird Banding Laboratory approximately 1.1 million birds were banded in 2001, with 689,019 being non-game birds.  Of those birds only 8057 were recovered and reported (ie found dead, collected for a museum, etc.).

Now I’m not saying 8,057 dead birds is completely trivial especially when they were all banded but this is only .1% of the total caught.  This also doesn’t mean banding was the  source of mortality.  More birds than that probably die but I’ve never seen any good evidence that responsible operations are a major stress on avian survivorship.  On the contrary the research of the Monitoring Avian Productivity and Survivorship (MAPS) and Monitoreo de Sobrevivencia Invernal (MoSI, the program AWA bands for) lead to significant knowledge on population health.

Although I wanted to see some good banding action, vacation was still on the forefront of my mind.  Rising at a late 7:30AM and strolling to the banding site was just fine for me.  Because the capture rates were typically low, I wasn’t going to band anything myself anyway.  The experience of handling birds is magical and since it was at a premium, I knew the students/field workers were eager for as much as possible.  I decided I’d just join the bird paparazzi, photographing birds in the hand is tons of fun.

Simone and Oliver had gotten in late the night before, having traveled down with Oliver’s parents separately.  We weaved down the road, distracted by every little thing along the way.  It was already starting to heat up.

When we got to the banding tent, Mandy, one of the interns, already had a Streak-backed Oriole.  This was a bird I’d actually never seen before and although it was beautiful, it made me anxious to try to find one out of the hand (I’d eventually see a pair of them auspiciously close while sitting on the open air toilet in camp!).  Like many birds, you get a real grasp of actual size when their necks are clasped between your middle and pointer fingers.  Such colorful animals appear literally larger than life when they are drinking nectar from a Pitaya bloom.

A female Northern Cardinal came in shortly after, along with its cousin a female Pyrrhuloxia.  For congeners, their resemblance close up isn’t cut and dry.  A Pyrrhuloxia has its parrot-like orangish bill, giving them a subdued expression.  Cardinals (forgetting the obvious difference that males are painfully crimson in comparison to the only red highlighted male Pyrrholoxia) have a broader and longer pointed red bill.  The difference in bill size and shape eludes me because I know both are well adapted to crushing seeds and both have similar feeding habits.  A guess might be that the Pyrrhuloxia due to arid obligation uses the likely more fierce leverage of a parrot-like bill on thicker husked desert seeds and more heavily armored desert insects (making an assumption that desert seeds and insects layer against desiccation).  And maybe I am just exaggerating the differences of their bills.  I admit that in silhouette, these birds are almost inseparable.

More birds continued to come in.  It looked like this wasn’t a slow morning.  Another potential lifer, a Black-capped Gnatcatcher was quickly processed.  A bird that couldn’t be banded with AWA’s federal bands (because each state separately administers their populations), a female Gambel’s Quail got caught in the net.  Offering a unique looks at it’s captivating blood-red eye and extensive patterning a Cactus Wren was brought in.

The final bird before I decided to head back for breakfast (I’d already been feasting on leftover tamales from the night before) was a male Gila Woodpecker.  You could hear this bird from moment it came into earshot and the screaming didn’t cease till we released it.  Most people thought Adam was joking when he said he hated them but having banded plenty of talkative woodpeckers, I could relate.  Still I couldn’t help but admire the smooth cream-colored head and underside in comparison to a heavily pied topside.  A tarantula-hawk that had been following me around unnervingly had thankfully switched interest to this hysterical bird as it buzzed close.

In retrospect I am kicking myself for not joining the banding operations everyday during the trip. The MoSI program isn’t run like MAPS, whose banding stations I have worked in since high school.  They run pulses of 2-3 days in a row, with 16 nets set.  MAPS will typically make regular single day samples of various regional sites or a continuous period of banding in one location.  MoSI is essential because it connects data from breeding grounds in the US and Canada with wintering sites in the Neotropics.  Not understanding winter grounds would be very short-sighted considering that half of the bird the bread in temperate North America winter in Mexico and beyond.  This was a great opportunity to see birds I’d never handled before or even seen in the hand.  As soon as I left they caught a male Varied Bunting a bird exhibiting a glory of both structural and pigmented coloration.  The next day they had a Greater Roadrunner and Black and White Warblers!

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