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 (which is excluded from North American counts), and set a 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. I’m sure all four of these birders are glad to get a chance to rest.

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.

EFFECTS OF BIRD FEEDING

Feeding birds is a common practice for hundreds of thousands of Americans. Over 40 percent 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 recently published a paper describing their nuanced perspective on the impacts of bird feeding. Malpass is a Colby College graduate who recently completed her Ph.D. at Ohio State.

Malpass’ work investigated the impact bird feeders had on nest predators from 2011 to 2014. On 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 carefully canvassed 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 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 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 nor negative effect. Our joy in feeding birds, at least for two species, does not entail unintended negative consequences.

Herb Wilson teaches ornithology and other biology courses at Colby College. He welcomes reader comments and questions at

whwilson@colby.edu

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