Imagine you’re an albatross, a large seabird that spends months aloft over the open ocean. Now it’s the breeding season: time to head back to your favorite island, do some amusing courtship dances, and lay an egg. But you’re in the middle of the vast, featureless open ocean. How do you find your way back?
Homing pigeons, taken from their roosts and driven up to 800 km away, can fly home. (Several pigeons have received the animal version of the medal of honor for doing this while carrying messages in wartime.) Arctic shorebirds like the Red Knot will fly from the Arctic to southern South America, over 13,000 km, twice a year. Birds are very good at navigation. How do they do it?
A conference, a brief vacation, and getting back into non-field-work have conspired to keep me away from the blog for far too long; humblest apologies!
Red-breasted Nuthatch scoffs derisively at your apology!
The conference was the North American Ornithological Conference, which combined the usually-separate annual meetings of many ornithological societies into one gigantic über-meeting with 1500+ attendees, almost all of whom were presenting their research as either a talk or a poster.
Although the last month has brought nests, chicks, and all the excitement they entail, it has also seen increasingly frustrating field work. In the beginning of the field season, we caught between two and five juncos every day; now we’re down to two, one, or none.
Some of them simply don’t respond to our playback at all. Locations that we know have juncos—because we’ve seen them, darnit, we’ve banded them—appear junco-less, our Radio Shack speaker spewing junco calls with no response. Other juncos respond half-heartedly, distractedly. They sing for a minute, then resume foraging. Or, as I watched GAEL do recently, they sing back softly while preening their feathers.
GAEL ignoring us. Photo by M. LaBarbera.
We spend a lot less time handling birds now, and a lot more time muttering, “Jerk juncos.”
Melanic color-dependent antipredator behavior strategies in barn owl nestlings. By Valentin van den Brink, Vassilissa Dolivo, Xavier Falourd, Amélie N. Dreiss, and Alexandre Roulin. Behavioral Ecology, 2011.
I’ve been slacking off on the Featured Papers, since it’s the field season and I’ve been reading
almost nothing less than usual; but this paper is too crazy not to mention.
The baby crested geckos are almost three months old now. Both hatched at 1.9 grams; October now weighs 3.3 g, which isn’t bad. (Geckos have a rather different growth rate than juncos, you’ll notice: juncos hatch at about 2 g and are at 3+ the next day!)
Poor ROAR. He has good subcutaneous fat and a decent mass (18.6 g), but he looks like he’s having a rough summer.
One of birds’ most endearing qualities has to be their care of their chicks. Sparrows fly in and out of nests in the rafters of gas stations, doggedly exhausting themselves to feed their hungry offspring; ducks and geese lead lines of fuzzy yellow babies across roads and around ponds; and we humans see ourselves in this tender parental care, and say “Aww.”
But child-rearing in birds is stranger than you think.