Christmas Bird Count increases
Last time I covered some of the species showing local, and often also national declines, as shown in the data from the annual Christmas Bird Counts. I half-heartedly promised to cover the increasing trends this week, and, against all odds, this is me remembering to do that. But before we get to the winners in the local bird world, I want to right a wrong that I committed on air recently. In reference to the National Audubon’s Christmas Bird Count website, where anyone can create trend graphs for any count or species, I said it was a bit clunky. That was before I realized that they had recently added a slick, easy tool for anyone to look at trends of select species. It’s called CBC Trends Viewer. I used it a good bit to research this two-part series – along with Mass Audubon’s excellent State of the Birds website that includes lots of trends and expert analysis.
Most of us know of the Bald Eagles meteoric rise here on the Cape and Islands, and the data certainly supports what we’ve seen with our eyes. In Massachusetts, Bald Eagles show a ridiculous 9.5 percent annual increase in the Christmas Count data. This reflects not just the local increase but a regional increase, as our local birds are joined by birds from other regions during the winter. Beyond our borders, Bald Eagles are increasing everywhere, thanks to the banning of the pesticide DDT, major national and state environmental legislation, and years of work moving chicks around to reestablish populations that had blinked out.
While many hawks have increased in our area, including Red-shouldered, Sharp-shinned, and the familiar Red-tailed, none have increased as much as Cooper’s Hawks. This bird-seeking missile of backyards and woodlots has made its peace with suburbia, and has the population increase to prove it. They show close to a 9% annual increase in the Christmas Count Data, and your feeder birds aren’t happy about it – they primarily eat birds along with a few chipmunks and squirrels for a little variety. If you keep backyard chickens you probably found out why they used to call them “chicken hawks” in the old days. Their increase has been implicated in the decline of one species I mentioned last time, the American Kestrel, because Cooper’s Hawks do directly prey on them. I think they may also be partly to blame for the puzzling decline in Mockingbirds, who like to sit at the top of a shrub, as if inviting predation.
The American Robin is the perfect example of a bird that, if they had thumbs, would give us a big “thumbs up” for how we have changed the landscape. In summer, they love to breed in the woods and suburban neighborhoods that sprouted up on all the old farmland. In winter, they love to eat the ornamental crabapples and multiflora rose hips we’ve littered the landscape with. And in spring they love the grassy golf courses and highway medians. Like Bald Eagles, they’ve been spiking a big 9% annual increase in recent years.
Warmer winters and an increase in forest explain the big increases we’ve seen in Pine Warblers, Eastern Phoebes, Ruby-crowned Kinglets, and the woodpecker known as the Yellow-bellied Sapsucker. In my lifetime, since about 1974, the average high and low temps on these winter counts have increased 5 degrees, which likely explains why we see more species overall now.
So there you go, some good news. While it may seem like we conservation types focus on the declining species to the point where we risk causing mass depression, it’s not all bad news. Just mostly bad news. Speaking of which, I’m done – time to get back to the bad news. Sorry, I guess it’s just called “the news”.