a leaf warbler's gleanings

I've noted the so-called "luxury effect" in the distribution of biodiversity in urban areas on this blog before, as seen in the pattern of higher bird diversity in the more affluent areas of Fresno-Clovis, and in cities as far removed as Phoenix, Arizona and Leipzig, Germany. Well, another piece of evidence supporting this pattern was published yesterday in the letters section of The Fresno Bee! Radley Reep, a local birder who rang me up just a week or so ago to talk about potential collaboration with the Fresno Bird Count, wrote the following letter based on his own independent survey of ponding basins in Fresno. Now this is real citizen science! Here's the letter in its entirety:

I'm an avid birder. Recently I conducted an inventory of birdlife in Fresno's 130 ponding basins. The result surprised me.

For example, I would not have guessed that some waterfowl prefer inundated ponding basins north of Shields three to one over those farther south. This called to mind many differences between north and south Fresno.

The north is far more prosperous. There you can find more facilities for higher education, a greater number of well-known chain stores and a plethora of fast food restaurants. There are gas stations everywhere and much newer cars traveling much better roads.

The north is cleaner and greener. The sidewalks at ponding basins have less graffiti, the basins themselves much less trash. There are more curbs and gutters, more manicured lawns, larger wooded areas and open spaces.

While birds vote with their wings, people can't always vote with their feet. Some waterfowl have chosen north Fresno, but some south-Fresno residents may not have the resources needed to participate in that bounty.

Perhaps, one day, Fresno leaders will fashion an equally pleasant environment in south Fresno. Should that happen, then a simple inventory of birdlife may be the best measure of their success.

Radley Reep

Clovis

What's interesting about this result is that we are not talking about private ponds, but mostly public ones used for flood control. Which means that it is not only what people can afford to do on their own properties that can attract or repel more species of birds, as found in the previous studies. These waterfowl are preferentially selecting ponds in more affluent neighborhoods even though the ponds should be under the management of a single public agency - the county flood control district! So does the differential selection of ponds by neighborhood income indicate differences in how the ponds are managed? Reep already points out how graffiti-/trash-free ponds are in richer parts of town - although that explanation may not satisfy many birders whose first stop in a new city may well be the city dump or sewage treatment plant because that's where many cool waterbirds are! Or is the surrounding matrix of residential areas influencing habitat selection by the waterfowl? Or is it a combination of these and other factors acting in concert? Something to look into there, eh?

And I'm with Reep entirely in urging city leaders to take note of these socioeconomic disparities in access to nature and biodiversity as another dimension of environmental injustice - but one they can do something about especially in their planning for urban green spaces and ponds!

References:

Ann P. Kinzig, Paige Warren, Chris Martin, Diane Hope, & Madhusudan Katti (2005). The Effects of Human Socioeconomic Status and Cultural Characteristics on Urban Patterns of BiodiversityEcology and Society, 10 (1)

Michael W. Strohbach, Dagmar Haase, & Nadja Kabisch (2009). Birds and the City: Urban Biodiversity, Land Use, and Socioeconomics Ecology and Society, 14 (2)