A few days ago I enjoyed observing a diverse array of different species of birds at my backyard feeding station. The collection of species reminded me of the terms I learned many years ago in my university studies about biology and wildlife management—species diversity versus species richness. Whereas species diversity relates to the number of the different species plus the number of individuals of each species in an area, species richness is simply the number of species in an area. With the latter term, the more different species present in a sample, the “richer” the area is.
Though I have no idea what each of these specific avian wintertime population measurements might actually be in my neck of the woods, I can confirm that at least in one tiny Becida area subplot (my backyard!), species richness is alive and well. For on that one bitter cold morning I counted no fewer than a dozen different species assembled together at one time: some feeding on the ground, some on the suet, some in the feeders and some in the trees above waiting their turns.
The species rundown included these happy dozen: black-billed magpie, black-capped chickadee, common red poll, blue jay, downy woodpecker, European starling, hairy woodpecker, pine grosbeak, pine siskin, red-bellied woodpecker, rock dove (domestic pigeon), and white-breasted nuthatch. Had I stood at my window for a longer period of time, I might’ve seen more.
As pleasurable as observing these dozen species was, it’s very possible that I’d observe more individuals of these different species of birds, plus perhaps observing a few more different species, if I introduced more diversity in the types of foods and other things that attract wild birds into my backyard feeding station. In fact, I can go out on a limb here and predict that species diversity and species richness would increase if I did so.
I frequently talk about wild birds with a woman I work with. She’s enthusiastic about watching and feeding birds and observing wildlife of all kinds. Our lunchtime conversations are often filled with stories about what kinds of wildlife each of us have recently observed. The two of us are a lot alike in our appreciation of nature, yet we seemingly part ways slightly in our approach and management of our backyard bird feeding stations.
Her bird reports generally include species I don’t often observe. Habitat certainly has a lot to do with this, but what she feeds and provides wild birds visiting her feeding stations contributes greatly to the differences. While I have always kept it simple by feeding just two types of foods—black-oil sunflower seed and suet—my friend feeds different seeds, suet, AND water. She maintains a heated bird bath that her birds use on a daily basis.
Indeed, bird diversity is generally enhanced in environments that provide all the essential elements that all species of wildlife depend upon for survival: food, water, shelter and space. Remove just one of these four critical components, species diversity and species richness will not be as great.
Another friend of mine who lives in Bertha, Minn., recently reported to me that two pairs of northern cardinals are visiting his feeders. Excited about the discovery, he soon purchased seed mixes that contain bits of fruit and other favorite cardinal foods. He also feeds thistle seed, both striped and black-oil sunflower seed, as well as suet and millet seed and other mixed birdseed that includes corn and other food. As a result of the diverse foods he feeds to his wild birds, he reports more pine siskins, American goldfinches, and, now, northern cardinals.
So what’s the bottom line in attracting more and/or different wild birds to our backyard feeding stations? It’s simple: to attract more wild birds and more different species of wild birds, the key is to think diversity in our approach to how and what we feed our wild feathered friends as we get out and enjoy the great outdoors.