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Visualizing the Pitayal Pt. 3 – Birds in the Hand


Thanks for visiting Wingtrip. This post is a part of a project called Visualizing the Pitayal. Click here for an explanation of the project. Click here for a complete listing of all the posts in the project so far, to start at the beginning. And if you are impressed by what you learn and see, consider supporting the Alamos Wildlands Alliance. Thanks again and enjoy!

Waking up in Navopatia after days on the road is immersion into a magical place. Especially because we’d previously writhed out of our sleeping bags and groggily listened to the sounds of urban Tucson. Now with a new day, new voices signaled dawn.

There’s a good reason so many people find themselves enamored with birds; it’s because of their diversity and their obviousness. Their sounds dominate dawn in practically every terrestrial habitat on earth, creating the often profound dawn chorus. The desert, is no different in this regard.

In the northernmost Neotropics, February is most assuredly spring, but vastly different from the temperate spring. There’s no predictable rains, but birds are breeding or preparing to. Some territories are being established in anticipation of burgeoning food and some parents are already incubating.

Despite being travel weary, this dawn was sleepless for the excitement of familiar desert sounds painted across the canvas tent. During the night my eyes had cracked open in a confusion of light, not knowing where I was. The moon filtered over the mangroves, shining off the estuary in spectral rays through the columns of cacti; the monochrome of darkest morning in full moon. When the chorus hit my ears, I woke again in confusion, but found myself exactly where I wanted.

Every morning, the cacophony of waterbirds in the estuary always mixes with the elegant singing onshore. As the double notes of Curve-billed Thrashers sounded from the tops of the pitaya, herons croaked in the shallows, jostling for the best feeding grounds. A Bell’s Vireo, effervescent, yet monotonously vocal, passed nearby. A Caspian Tern matched with squawking tones. Cardinals, Verdin, Costa’s Hummingbirds, Northern Mockingbirds, Gila Woodpeckers, and more continued their dawn greeting as the rising sun finally rousted me.

Passerines and other terrestrial species, are typically most obvious and active during early, cooler hours of the day. Thus, if you are an ornithologist focusing on terrestrial, desert ecosystems, you rise early and work till the day is hot. Of the many early morning efforts at the field station, banding is definitely the most fun to observe.

What exactly is banding? Broadly it’s catching birds in mist nets, placing a small metal band with unique numbers on one of their legs, taking a series of measurements, and then releasing them to go about their lives. Count based field methods, where people survey an area for presence and abundance of bird species with sight and sound for detection, give good baseline data for conservation and land management. However, they don’t tell the entire story. Counts provide little or no data to understand bird survival rates, morphology, where they migrate to and from, and much more of their general natural history. Bird banding informs demographics and can guide effective conservation efforts.

Adam Hannuksela is the Director of Research of the Alamos Wildlands Alliance and has a constant assortment of projects on his hands. The first morning at the field station, Adam was banding with two interns, a visiting friend and biologist, Aaron Holmes, and the indispensable field assistant (amongst many things) and resident, Tino Mendivil. When we arrived at the banding table at relatively late hour of 7AM on the first morning and things were in full swing.

The field station participates in the Institute for Bird Population’s Monitoreo de Sobrevivencia Invernal, also known as MOSI. Translated into English, the program does as its name suggests, monitoring the winter survival of birds. This program aggregates data from participating banding stations all across the Northern neotropics. Navopatia is one of the more northerly stations contributing. This data is used in conjunction with Monitoring Avian Productivity and Survivorship (MAPS) data, a project North of the border in the US and Canada. MOSI fills the gap for studying many neotropical migrants, because most that breed in Canada and the US, spend up to half their year in the tropics. MAPS has many well-funded stations, and while MOSI is growing, it’s severely underfunded. The reality is that wintering grounds are a sizeable chunk of the equation for migratory birds, so the work stations like Navopatia are doing is vital.

Spend enough time with some nature nerds and you’ll probably end up holding a wild animal. These situations may, or may not, be respectful, despite the learning opportunity they can provide (many of the lizards, amphibians, small mammals, and birds I’ve held didn’t contribute data to science). I get a strong satisfaction out of simply holding a bird, observing details, and yes, taking close pictures, science aside. However, I would never shade bird banding beneath this umbrella; it has a purpose.

Over the course of the two days I spent at the table, several birds were banded but not masses. This is good for the interns, because most of them are beginning banders. The point of banding is to efficiently and safely collect data on the captured bird with correct identification, precise measurements, assessment of a variety of scales, and through process hopefully determine age and/or sex of the bird. This sounds complicated and it is; a huge part of banding is ensuring precise data, so the stress on the birds is not in vain. Trained professionals are extremely fast because of practice, beginners less so. Add more birds to the equation and the stress of trying to get the birds on their way encourages mistakes. Thankfully there were fewer birds and therefore fewer mistakes.

Often times a minute is needed to study certain feather groups, to grapple with a particularly active bird, or often, to stare vacantly at the “Identification Guide to North American Birds, Part I” by Peter Pyle. Banders call it the Pyle Guide for short. This black book is a wonderful resource, but is equally full of dreadful, cryptic jargonism. Washing all North American passerines (and some closely related non-passerines) with broad enough strokes to generalize molt, coloration, age, and a myriad other details wasn’t an easy task, but that doesn’t alleviate the frustrations with it. For the uninitiated, it looks like a jumble of nonsense; for the initiated, it can still appear so. A good degree of certainty can be attained by it’s use, as an essential work achieved only by admirable dedication. Most banding operations would be lost or taking much less data without it.

Of course, these birds don’t just fly to the table. Mist nets are placed in strategic locations through the pitayal near Navopatia. These nets are fine, nearly invisible walls of fabric, held up by lines suspended between two poles to create rows of pockets to entangle birds. All the nets are in lanes, cut out of the scrub, set within walking distance of each other, but well concealed. Birds fly through the landscape, not seeing nets nor anticipating impact. Every 30 minutes or so, a “net run” happens to check for captures. Birds are extracted and put into small cotton bags (to allow free hands for extracting more). The extraction can be time intensive for beginners because of the delicacy of the birds, their struggling, and the net’s fine mesh.

The variety of birds banded at Navopatia are a flurry of size and color. They caught birds like Streak-backed Orioles, which are gaudy tropical residents. Orange-crowned Warblers are common here, a tiny, familiar bird to US birders, that flies hundreds, if not thousands of miles South to winter here (without banding data, an explanation of this is another story, there would be less knowledge of how orange-crowned warblers distribute in winter. We know that all three subspecies intermingle in Mexico, but that the two more Western forms are more common on the Pacific Slope. Who cares? In terms of conservation, knowing what species, and subspecies, are using which habitats throughout the year is vital information.). Others are more distinct desert residents, but also backyard birds for people stateside, like hefty Cactus Wrens. Noisy Gila Woodpeckers and startled Common Ground-doves were also nabbed. All were quite novel to people who’ve banded primarily in the temperate zone, but I could have seen these birds thousands of times in hand and I’m fairly certain I’d still find their closeness thrilling. Besides, I have to admit that half the fun is holding them.

As the banding slowed, the MOSI schedule for the month was over and the field station staff needed to move on to other work. We set about taking the mist nets down, as they are both fragile and valuable, but the net lanes remain in tact for future banding efforts. The birds will be there too, and hopefully because of the data, for a long time to come.

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