Tuesday, January 6, 2009

The more things change...

In the spring of last year, I devoted an entire week of my time to learning the gritty details of the sex life of one pair of Northern Rough-winged Swallows. This endeavor involved me sitting in a dirty creek channel for hours and hours without break, glued to a camera screen. It was a trying experience, but wonderful in that I got to see a lot of wildlife I otherwise would not have encountered.

A lot has happened since then. I graduated from Cornell, for one. I spent most of the summer in the lab finishing a big phylogeography project. Then in the fall I said goodbye to Ithaca and departed for Venezuela. Then a month and a half into my job in Venezuela... I found myself sitting around in uncomfortable places, glued to a camera screen for hours and hours. Funny how life works sometimes.

May 2008

October 2008
If you've been following my posts on the Forpus project, you'll know that I spend a lot of time tracking individual parrotlets by identifying their individual color band combinations. This involves a lot of sitting and waiting for a pair to show up at their nest box, then a lot of squinting through old scopes trying to read faded colors in the harsh sun. Early in the season, this is easy. If we don't get the identity of a pair before they begin nesting, it gets more difficult.


Green-rumped Parrotlets (Forpus passerinus) are asynchronous hatchers, meaning they begin incubation upon laying the first egg. They lay huge clutches, up to eight or nine eggs, so that egg-laying is spread over 10 days or more. Incubating this whole time means the chicks also hatch out staggered, so there is a great discrepancy in chick size.

The downside for us parrotlet biologists is of course that, once a pair begins a nest, the female starts incubating... and stays inside the nest box for the majority of her time. This makes it very difficult to resight her color band combos. I've sat for hours while a female sits around inside her nest out of sight, climbs up and peers out of her nest box, sits contentedly at her entrance (with legs hidden) for an hour, then suddenly goes bursting away in flight when the male arrives and they fly off together, come back fifteen minutes later when the male perches on the nest in plain view and the female zooms down inside the nest like a rocket, without even a glimpse of her bands showing. It's quite frustrating.


Things improve over time. The eggs hatch, and both parents have spend time gathering food for the rapidly growing mass of baby parrotlets inhabiting the nest box, meaning lots of opportunities to read bands on entering and exiting birds. Any unsighted color combos are read by now. However, another fun sit-and-wait activity replaces band resighting at this point - video sits.


I won't go into the details of Karl's research other than to say it involves recording the vocalizations of adults and nestlings in the nest. This involves rigging cameras and microphones inside and outside the box so we not only record the calls of the parents on the perch and the calls of the family inside the box, but we can synch it to the video so we know who it was actually calling at any given point. To help with this we mark the chicks on the top of their heads. After marking, we retreat to the limit of our cables and wait. We wait for hours to record several feeding visits by the parents and the nestling's begging calls.


The time in between feeding visits can vary from half an hour to an hour and a half (we call those ones the bad parents!). This means a lot of downtime, confined to my folding chair, waiting for the pair to show up. I can't really wander or not pay attention so I can be ready to hit record and not miss a second of the feeding visit. It's a good time to watch the thunderstorms swell and approach.


Long periods of time spent sitting still (sometimes in the shade, but even more so out in the open searing sun) seems to attract the Black Vultures (Coragyps atratus), abundant on this cattle ranch. This group seemed to think I was dying in my chair as they slowly approached from behind.


Finally, after weeks of work and stress reaching its peak, we broke down and took a more direct approach to recording parrotlet nestling vocalizations. Problem solved!*


* - Not really. We kept filming every day until every last chick fledged. We were practically shooing the last few out... fly! fly! you can do it! Git going!

4 comments:

  1. A commendable effort to be sure! I hope your research goes well.

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  2. Thanks for the good pics and field notes that allow us to "virtually" visit another ecosystem.

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  3. Thanks guys! I'll try to keep up the efforts :)

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  4. What a cool little bird in the last shot.

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