Some species of North American hummingbirds are in severe decline and a British Columbia research scientist says one possible cause might be the same insecticide affecting honey bees. Christine Bishop with Environment and Climate Change Canada said researchers started looking at a variety of factors that may be responsible, ranging from habitat loss to changes when plants bloom. To try and find some answers, researchers began collecting urine and feces from the birds for testing.
"No one has ever measured pesticides in hummingbirds before. So we decided to try it," she said in an interview. "It turns out, to our surprise actually, that the birds are obviously picking up pesticides in their food, which can be nectar and also insects." Christine Bishop, a research scientist with Environment and Climate Change Canada, says some species of North American hummingbirds are in severe decline. Bishop said the concentration found in the urine is relatively high at three parts per billion.
"Now what does it mean? Right now we're just understanding what the level of exposure is, and then how is it affecting the population, well that's part of the population dynamics," she said. Her research is focused in the agricultural regions in the Fraser Valley and southern B.C. — the core area for the rufous hummingbird. The rufous is a feisty, red-throated bird that weighs about as much as a nickel and spends its summers in B.C., Alaska and the Pacific Northwest states, then migrates to the southern United States and Mexico.
The testing doesn't harm the birds. Researchers hang a net over a feeder and then lower it like a drape when the bird comes to feed. Because the hummingbird is constantly processing nectar, it is also constantly expelling it, and Bishop said by the time they are banded the bird has likely expelled urine and feces to test.
Hummingbirds are birds from the Americas that constitute the family Trochilidae. For nutrition, hummingbirds eat a variety of insects, including mosquitoes, fruit flies, and gnats in flight or aphids on leaves and spiders in their webs. The annual breeding bird survey shows that between 1966 and 2013, the rufous population on the Pacific Coast dropped an average of 2.67 per cent per year. The survey says the Allen's and broad-tailed hummingbirds were also in decline.
CBC News, July 9, 2017