social behaviour – Dynamic Behaviour Lab

Saturday, March 25 was Peacock Day at the Los Angeles Arboretum. I was looking forward to giving a talk at this event for months because it was a chance to return to my stomping grounds at the best time of year.

The event had guided peacock walks, peacock-themed art activities, sitar music, and an Indian food truck (because the species is originally from India). It was a hit – when I arrived in the afternoon there was a huge lineup at the park gates. Total attendance was over 4,400, the biggest day of the year for the Arboretum. There was even a bump in attendance the following day (2,800), because of people who missed the peacocks on Saturday.

My talk was in Ayres Hall (the same building we used to trap many of the females 7 years ago), with 170 people in the audience. I suggested that if we want to give credit where credit is due, we should really call it Peahen Day, because peahens are responsible for the evolution of the peacock’s amazing display.

I also talked about why I think the species does so well in California (and other places). I think it’s because peafowl are social (they stick together as an effective defense against most predators), because they are quick learners, and because the chicks spend a long period of time following mom – around 9 months, actually. That’s a long time for a bird! It provides many opportunities for mom to transmit skills that allow her offspring to handle new environments, like what to eat, how to hide, and even how to cross the road.

I think the main thing we’ve learned from our research on peafowl is the importance of dynamic signals during mate choice. i.e., it’s not just what a peacock has that makes him beautiful, but also how he uses it. A major theme in evolution research today is whether sexual selection speeds or hinders adaptation. Although we don’t yet know whether sexual selection has promoted adaptation in peafowl, we can say that they have spread around the world because of their sexually-selected traits. We brought peacocks to California, Hawaii, Florida, New Zealand, and many other places, because they are beautiful in our eyes as well as those of the peahen.

I woke up the other day to see this:

A little closer:

Those aren’t leaves covering the trees – they’re crows! There must have been a few thousand of them (the picture only shows part of the flock, which extended to cover several other trees and rooftops). This is the third time this winter that I’ve seen a mega-roost in downtown Ottawa. Each time it has been on days that are much colder than usual. By noon, the flock had dispersed.

We had more bird encounters in Quebec last week where we saw a partial albino black-capped chickadee:

Here’s a black-capped chickadee with regular plumage, for comparison:

In domestic birds, partial albino (pied) mutations are recessive and fairly rare. It took about 100 years of cockatiel breeding before the pied mutation was established in the US, in 1951. I can’t find published numbers for chickadees, but bird banders counting mourning doves have recorded only 1 partial albino among 10,749 individuals. So this was probably a pretty rare bird! And here’s Ada, no longer impressed by a regular old chickadee: