The Birds

So although I've explained that I am here in Peru to study birds, I haven't really explained how we go about doing so. The majority of what we do in the field is called "constant-effort mist-netting." This mean that we set up mist nets in specific locations and leave them there for a certain amount of time, and process whatever birds we happen to capture in them. As you can guess, this means that we rarely catch canopy birds that spend most of their time at high altitudes (like macaws and hawks). There are other types of mist-netting, including "target netting," which we haven't done yet but we may do in the future. Target netting involves identifying where a target species or a specific bird is and bringing a net to that area to try and capture that bird. Since I haven't ever seen this I'm not really sure how effective it is.

Birds obviously get really stressed out when caught in the nets and being handled by humans, so we do net checks every 20-40 minutes, depending on the weather conditions (more often if it is sunny, really hot, or raining). Detangling birds from nets is very similar to detangling bats, in my opinion. I think it might even be trickier because birds tend to clutch at the nets with their claws, so once you free their legs, if you happen to let them go (this happens to me all the time) they will just tangle themselves up again.

Once the bird is freed, we stick it into a small cloth bag (less likely for them to escape and much more calming for them) and bring it back to the banding station, which is always located a little ways away from the nets so we don't scare away the birds. Then the bird is processed! The first thing we do is band the birds on their legs. All birds get aluminum metal bands on their tarsus. Some birds also get color bands too, although this depends on the bird and the species. We don't color band birds if we can't tell whether they are juvenile or adult (with many species there is no way to tell), or if they never perch in such a way that we would be able to see the bands (certain types of woodcreepers).

One of the first days - I am probably confused.

Second, we cover the bird in an ectoparasite powder to remove all their ectoparasites for analysis. Then we take a lot of data from each individual. We quantify the amount of muscle, fat, molt and feather wear, whether they have a brood patch or cloacal protuberance, take measurements of their culmen, gape, and tarsus, record the colors of the eye, the skin around the eye, and the tarsus, and take their weight, a photo, and blood sample. As you can tell, this takes a while, especially when you are first learning! It's also easy to let a bird escape (even Judit does it sometimes), so you have to pay attention the whole time. Sometimes the birds get really tired or stressed when being handled, so you just collect as much information as you think is safe (probably no blood sample) and let the bird go. We've had an unfortunately large number of bird deaths so far this year. :[

We catch quite a few hummingbirds (maybe 1-2 a day at the last site), which get a little bit different treatment because they are more frail and have basically no tarsus. Instead of banding them, we clip one of their tail-feathers at a diagonal to show that it is a recapture for the future. We also don't take blood or ectoparasite samples from them. I like the hummingbirds a lot, they are very cute, but they escape easily because they are so quick!

If we recapture a bird that we have just banded at that site (from the same day to two days before), we just double-check that we have all the information and let it go. If we recapture a bird from a previous year, we process it fully. Some birds learn very quickly about the nets, and once they are captured you never see them again. But other birds aren't so lucky (or smart) - at least once we caught the same bird 3 times in one day.

I'll update the name of this one later!

This one also!

Saffron-crested Tyrant-Manakin (Neopelma chrysocephalum) - one of our focal species!