Small urban colonies HAVE established but we did not know who was using them. Now it looks like they may be used by some individuals that have dropped their yearly migration when they urbanized. That is not surprising, but it is cool to see it happen!

I had been told that ibises traditionally migrate to vast Everglades colonies to breed. Even when they winter in urban parks!

But this map suggests some urban birds may now complete their entire breeding cycle in urban habitats.

The idea started with a paper indicating that bill color in american White Ibises is a good predictor for breeding state:

🔴 Bright red = breeding ready
⬛ Black patches = eggs laid/chicks hatched

With each shift in color, we can track the ibis life cycle—no nest disturbance required.

and apply that transformation to patches taken from their bill. It has been helpful but I did have to go a bit further and normalize brightness and saturation as well. I have also been measuring the proportion of their bill that is black.

I have ran into issues since all photos are taken using different devices and under different light conditions. But I have taken advantage of ibise's white plumage to normalize their color. Very simply, I look at how white is their white, turn that into actual white (R255, G255, B255)

As their nesting progresses, eggs are laid and chicks grow up, their bill slowly develops and black patch and slowly becomes duller. Thus, how their bills look tell us a lot about their breeding activities! I have been working on using community scientists' photos to estimate breeding state.

That's where the community scientists' submissions come into play: likely because of their asynchronous breeding, ibises have developed a mean to communicate to potential partners about their status. Individuals that are ready to mingle develop a vivid red bill.

We do see a stark reduction in urban ibis populations at their urban "wintering" grounds in the summer, but they're not necessarily all gone. Plus some urban colonies have started emerging, which bids the question: do these urban breeders stick around urban parks in the summer?

For instance, a big factor that explains movement and distribution is whether or not they are currently BREEDING. Ibises presumably have a long breeding season (march-october though we'll get back to that later). When they do, they are thought to join big colonies in the Everglades (2/n)

Sharing an article I wrote about vertebrate scavengers, the topic of my Master's thesis. I worked in Madhya Pradesh in Central India, studying vertebrate scavenger communities in two different protected areas - one with an abundance of vulture, one without.
roundglasssustain.com/wild-vault/s...