Now that 2016 has ended, it’s time to check on the Big Year efforts. John Weigel shattered the old North American record of 749 species seen in a calendar year by finding 781 birds! Three of his species are new to North America and must be accepted by rare bird committees before their official inclusion.
Olaf Danielson did nearly as well, finding 778 species (two pending). Danielson also spent time birding in Hawaii and has set a new record of 827 species in a year in the United States.
Laura Keene ended her Big Year with 759 species and Christian Hagenlocher exceeded his goal of 700 species by documenting 750 species. I’m sure all four of these birders are glad to get a chance to rest!
On a more local level, Josh Fecteau of Kennebunkport did a Big Year in Maine in 2016 and found 305 species. An extraordinary effort! You can read about Josh’s Big Year at joshfecteau.com
The Effects of Bird Feeding
Feeding the birds is a common practice for hundreds of thousands of Americans. Over 40% of American households maintain a bird feeder. We know that bird feeding does increase the survivorship of birds and improves their physiological condition. Birds do not become dependent on our handouts. What’s the downside of feeding birds?
Jenn Malpass and two colleagues have recently published a paper describing their more nuanced perspective on impacts of bird feeding. Jenn is a Colby College alumna who recently completed her Ph.D. at Ohio State University.
Jenn’s work investigated the impact that bird feeders have on nest predators over the period of 2011 through 2014. On the one hand, if bird feeders increase the abundance of Blue Jays, American Crows or gray squirrels, other birds nesting in the area may be at a higher risk of losing their eggs or nestlings to those nest predators. On the other hand, providing food to Blue Jays may satiate them, reducing their tendency to take eggs or nestlings.
The research team used seven study areas in residential neighborhoods in Columbus, Ohio. Each neighborhood was about nine acres in area. The team got permission from most home owners to visit their yards. The team carefully canvased each area and noted the location of every American Robin and Northern Cardinal nest. The nests were checked every one to four days for evidence of nest predation. This project was an ambitious one; nearly 1,000 nests were monitored. The researchers also did visual searches for 18 different potential nest predators.
Unsurprisingly, multiple houses in each area had feeding stations. The research team placed additional bird feeders in three of the seven neighborhoods, essentially doubling the number of feeders. This supplemental food provided a direct test of the influence of bird feeding on nest predator abundance. Many of the potential nest predators could take advantage of the bird seeds (squirrels and several bird species). Others, like cats and raptors would not be directly attracted by tasty sunflower seeds, peanuts or millet.
As you can imagine, the statistical analysis is complicated. The authors first tested the effect of year-to-year variability and the amount of supplemental food available on the abundance of the various potential nest predators. Next, they tested the effect of nest predators and bird feeders on nest success.
The results showed that bird feeders do increase the abundance of American Crows and Brown-headed Cowbirds. However, this increase in nest predator abundance did not translate into reduced nesting success of robins or cardinals. The one negative effect was a reduction in robin nest success in the presence of high American Crow abundance and high bird feeder density. The main effect of bird feeders on nesting success is neither a positive or negative effect. Our joy in feeding birds, at least for two species, does not entail unintended negative consequences.