At the end of September, I had the opportunity to spend a couple of mornings at the Nature Center.
On both occasions, our activities were interrupted, as crystal clear songs from resident birds filled the air. Their songs were so beautiful that it was impossible to ignore them. The birds didn’t reveal themselves so that we could get visual identification, and no one in our respective groups could identify the birds from songs alone, unfortunately.
Their songs, however, reminded me of the headlines from the previous week about the overwhelming decline of songbird populations in North America over the past 50 years. According to a paper published in the journal Science by Ken Rosenberg, a conservation scientist at the Ornithology Lab at Cornell University, bird populations have declined by more than 3 billion birds since 1970. That’s a staggering number of birds – an estimate of more than 1 in 4 birds.
The report says dramatic losses have occurred in every biome, including forests, which have estimated declines of more than 1 billion birds and a 50% population loss in the grasslands. Losses have heavily affected just 12 avian families, including sparrows, finches and blackbirds. Together, these birds account for more than 90% of the decline. Habitat loss is blamed as the primary culprit for these declines, although there are other contributors as well.
The report provided some positive news, too. The populations of certain bird families, including waterfowl, raptors and turkeys, have actually increased. These particular birds have had concentrated conservation efforts in place for some time, and those efforts appear to be paying off.
This news takes an interesting twist, though. Science is a highly-regarded scientific journal and is lauded among the scientific community as a great source for studies to gain attention through common news outlets. As a result, the content of the scientific studies can often be constrained, with salient details omitted. Public relations and marketing often take higher priorities. Such was the case for this study.
Upon diving into more of the details of this study – beyond what was published in Science – there was some critical information that indicates the news about North American bird populations is not quite as apocalyptic as the headlines made it out to be. Upon review of the radar data used for the Science article, University of Maine Macroecologist Brian McGill reported on his scientific blog, Dynamic Ecology, that some of the biggest declines have come from two species, in particular – the European starling and the house sparrow. These two species are invasive birds, and there have been efforts to actually limit their populations. Apparently, those efforts have been successful, as these two species alone account for a declining population of more than 400 million birds.
McGill agrees with Rosenberg that the bird population has declined but figures that two-thirds of the 3 billion bird decline comes from 40 of the most common species of birds (out of 529 species total). No one is saying that these losses are unimportant. Rather, they are saying that framing news in a way that focuses on the sensationalist aspects rather than a complete assessment of the study skews understanding and leads to a distrust in science.
It behooves us readers to read carefully, think critically,
and educate ourselves about how to live in a way that helps sustain our feathered friends.