I’m starting out today’s post on the big picture with a little picture. The bird staring at you in this picture is a White Wagtail. This little male was present everyday on the patio of our hotel in Barcelona. Some days he was alone, some days he was joined by his children. One day, both adults were present there, too. Instead of getting into details about this particular species and what it was or was not doing in Spain, I’m going to go a different route and begin by reiterating where we saw it…on the patio of our hotel in Barcelona. Got it? Patio. Hotel. Barcelona. Patio. Building. Big city. Patio full of people. Human structure. Big city full of people. Yes! In the places where you might expect House Sparrows and Pigeons (they were out on the streets), we actually saw this little bird hopping around. Now White Wagtails are ground feeders and hole nesters, which means that they do have some specific sort of habitat needs. I can also say (to add into the mix) that I did not see Wagtails on every street corner. We found them in that one place and then sort of spottily distributed in the city. So, the question goes back to…why is it important to note where I found these birds?
Ah! That question is the big picture question! Having found the wagtails right there in the center of the city and noting the fact that they’re not just commonly found up and down every street, my brain goes towards thinking about how they got there in the first place. Clearly, birds can fly, so they could have flown there. There is, however, something amiss with that simple explanation. Birds don’t just fly anywhere. Why would a bird fly through the middle of the city and end up on a patio? To answer that question, we need to think about how birds make settlement choices. Birds don’t just randomly plop themselves in the middle of a habitat. They move from place to place slowly, generally speaking (excepting during migration events). Even then, the establish themselves in a large suitable habitat and then move around through it until they find a suitable nesting site.
Right there! Did you catch that? The answer to the question was there. Birds move through “suitable” areas. What does that mean? It means that the center of Barcelona- the center of the city, itself, is at least an area that those birds will move through. How did that happen? Well, to put that into perspective, I’ll go back to talking about one of those things that I bring up a lot- the greenway system in Charlotte. What are the greenways? Well, they’re paths of natural habitat along streams. What do the greenways do? Hmmm…They create connections between larger parks and natural areas. In conservation-speak, we call these connections ‘corridors’. The greenways are corridors that allow some species to move back and forth between larger habitats. Barcelona has a similar sort of situation. They don’t have distinct greenways along streams the way Charlotte is building. They do, however, have very distinct lines of trees and public parks that connect to each other. They have corridors built right there in the middle of a big city, too.
One researcher, Esteban Fernandez-Juricic, has published a fair bit on the functionality of tree-lined streets as a means to facilitate the spread and population stability of songbirds. Not all species respond the same way to the presence of trees on a street. Some still need larger pieces of forest, but many respond very positively to the creation of these areas as corridors.
Fernandez-Juricic, E. and J. Jokimaki. 2001. A habitat island approach to conserving birds in urban landscapes: case studies from Spain and northern Europe. Biodiversity and Conservation 10: 2023-2043.
So wagtails showing up on a patio in Barcelona lead to an appreciation of the effects that urban planning have on bird populations. Start small and think big (and go plant some trees up and down your street!).