Sunday, January 23, 2011

Salt on a bird's tail (Betsy)

Magnificent Frigatebird.
When my sister and I were little my mother used to tell us to go catch a bird. She said that if we approached a bird very slowly and quietly we could put a little salt on its tail and would be able to catch it. Armed with salt shakers my sister and I spent ages sneaking around the yard chasing down robins and chickadees that would quickly flit away. What my mother really wanted, and got, was a some peace and quiet without kids underfoot.

Isabela fishcamp.
We recently visited Isla Isabela, a small, rocky island off the mainland coast of Mexico that would have my mother running wild with a salt shaker. Isabela is host to an unbelievable concentration of seemingly tame birds. Other than a small fish camp and a tumble-down research station with a few birdwatching grad students, the island is undeveloped and predator-free.

Brown-footed Booby
The birds, brown- and blue-footed Boobys and Magnificent Frigatebirds, rule this roost.The boobys have got the ground covered and the frigates control the shrubs and low trees. Not to be outdone, large numbers of iguanas warm themselves each day before disappearing into rocky nooks and crannies when the sun goes down.

They might be yellow but these
are actually "Green Iguanas"
What makes this place so fascinating is just how approachable the birds and iguanas are. It's easy to get within a few feet without scaring them off. I'd happily salt and catch a booby in memory of my mother but I don't think the bird would appreciate it.

Looking for a hot chick!
Like the boobys, the frigates have an unusual mating ritual. The males have what looks like a red turkey wattle under their beaks that they inflate to attract a female. Once properly courted, the frigatebird builds its twiggy nest in low trees and shrubs and never leaves it unguarded for fear of losing its nest material to other frigatebirds.

Booby mother and chick
Walking around the shrubbery I was surprised to find the ground littered with eggs that awkward would-be parents bumped from their nests. Given the number of birds on the island I don't think the occasional lost egg will put the frigatebirds on the endangered species list any time soon. Following an elaborate courtship dance the boobys build a rough nest on the ground. After laying two eggs (the second is insurance should the first one not survive), the booby stays put for nearly a year to raise its young as well as protect the chick from an opportunistic frigatebird out for an easy meal.

Isla Isabela is an amazing place and well worth the small detour we made to get there. If you ever want a little kid-free time send your child into the garden with a salt shaker. If you want them to bring home a bird, take a trip to Isla Isabela.