Sometimes there are just too many birds
Can you have too much of a good thing? When you’re banding birds you can. I remember one cold morning in Denali National Park, Alaska. Unexpectedly, a huge push of migrating Wilson’s Warblers and Ruby-crowned Kinglets had come through, with seemingly dozens of birds in each net on every check. Since it was cold, we had to untangle the birds and get them banded as quickly as possible to ensure they didn’t lose too much weight or freeze to death. So my two colleagues and I ran around and around our set of 12 nets like madmen (and women) the whole day. By the time we closed our nets that afternoon we were all exhausted and wondering why we ever wished for days with lots of birds.
The same thing can happen in cannon netting. Because our goal is to keep captured birds for as short a time as possible – hopefully never longer than a few hours – on some big catches we sometimes end up with so many birds that we have to immediately release some before we can even put a band on their legs. This is always heartbreaking, especially because the first thing they teach you in “How To Be a Scientist 101” is never to throw away data. Better safe than sorry though.
On our last day on Chiloé with a full crew, we had an even more unusual problem: we had so many birds that we couldn’t even catch them. That’s right, they were just sitting there, all in front of the net, but we couldn’t catch them.
We had decided to return to Bahía Pullao for one last shot at a “big catch.” We had caught about 50 birds there the day before, but we thought we could get many more if we moved the net to the edge of a tidal creek on the other side of the bay.
We set up there the next day and sure enough, as the tide began to rise, birds piled in front of our net. First 500, and then as the tide rose even higher, 800 birds – mostly godwits – nearly standing on top of each other, crammed in between the tide line and our net. This was just too good to be true, we thought.
But then, before pulling the trigger, we thought a bit more. With the water just barely eight yards below our net, many birds would be pushed into the water as the net launched over them. And with so many birds, there was nowhere for the cannon projectiles to fall without harming some of the birds. All things considered, we felt there was too high a chance that birds would get injured. Very reluctantly, we decided to wait for the tide to crest and begin to recede, hopefully allowing the birds to spread back out a bit and giving us a more manageable catch.
The godwits had other ideas though. Shortly after high tide came and went, so did the godwits. In one mass they picked up and took off for other parts of the bay, leaving behind only a few stragglers aligned perfectly around the perimeter of the capture area. No amount of twinkling or bobbing polystyrene foam could get those birds back into the catch area. Maybe God felt we had already caught enough birds. Maybe the godwits were just playing a joke on us. Whatever the reason, we could do nothing but dejectedly pack up the nets and head back to Castro, to be consoled by some seafood and a couple of bottles of wine.
The next day, Larry Niles and his crew flew back to the U.S., carrying their nets and cannons with them. The rest of us spread across the island, looking for some of our newly banded birds. My group found three in the northwest corner of the island at Bahía Quetalmahue, about 100 miles from where we had banded them. Jim Johnson of U.S. Fish and Wildlife and his crew stayed on in Castro for another week to check up on the birds at Bahías Pullao and Chullec and to make sure that all is ready permit-wise for our return next year.
We cannot call our campaign anything other than a success though. We caught 204 godwits, 66 Whimbrels, and one Red Knot, and, because of decisions like the one that we made at Bahía Pullao, we released all of them as healthy as when we first caught them. We placed a satellite transmitter on a Whimbrel (maps will be posted on the Internet shortly, stay tuned) and resighted hundreds of birds that we had banded in the past couple of years and that have already made multiple 9,000-mile trips back and forth to the Arctic, each time returning to this same island.
We met with school children from around Chiloé, made the front page of the local paper, and told our story to readers like you. Undoubtedly the disappointment of this last day will soon fade and we’ll get to work analyzing our data and raising awareness about shorebird conservation. And, with any luck, we’ll be back on Chiloé again next winter to search for our birds, continue to help our Chilean colleagues – and maybe even place satellite transmitters on some Hudsonian Godwits. Until then, ¡Hasta luego y buena suerte! (That’s “See you later, and good luck.”)
All About Birds
is a free resource
Available for everyone,
funded by donors like you