Don’t Worry Birds Won’t Become Dependent on Your Food, OSU Study Finds | New
Researchers at Oregon State University have good news for the well-meaning masses who place bird feeders in their gardens: the small songbirds that visit feeders seem unlikely to develop an unhealthy addiction to them.
“We still don’t know much about how intentional feeding might induce changes in wild bird populations, but our study suggests that distributing food to small birds in winter will not lead to increased reliance on it. food supplied by humans, âsaid Jim Rivers, animal ecologist at OSU College of Forestry.
The research results, which looked at black-capped chickadees fitted with RFID tags, were published today in the Journal of Avian Biology.
Every year, hundreds of millions of people around the world distribute food to wildlife, including 50 million in the United States alone, resulting in a $ 4 billion industry based on food, feeders, and other accessories. But the popular pastime has long raised concerns about animals’ dependence on human-supplied food, especially during winter and other parts of the annual cycle that require animals to expend a lot of energy. .
“The extensive and widespread nature of people intentionally feeding wildlife can have unintended consequences for free-roaming animal populations, and these consequences are best documented in birds,” said Rivers. âOn the negative side, it can facilitate disease transmission, restructure local communities and change migratory behavior, for example. There is even some evidence that it can lead to changes in the structure of birds’ beaks. On the other hand, it can also have positive effects, such as improved body condition, winter survival and reproductive performance.
Bird feeding is especially popular in northern latitudes, especially during the winter, when cold, stormy weather and minimal daylight reduce the time birds have to find natural food. But not much is known, Rivers said, about whether birds become dependent on the food their human friends throw at them.
âThe only handling experience to test this, also using the black-capped chickadee, dates back 30 years,â he said. “He found no reduction in apparent survival after the removal of bird feeders that had provided supplemental food in winter for 25 years, leading to the conclusion that bird feeding did not promote addiction to feeders. “
Rivers and colleagues studied the feeder usage patterns of 67 black-capped chickadees subjected to one of three flight feather trimming treatments: heavy mowing, light mowing, or, as a control, no mowing. . Experimental removal of primary flight feathers is an established technique for altering wing loading and increasing the energy costs of flight, Rivers said.
The birds were tagged with RFID tags, and 21 bird feeders along a 2 mile riparian area were filled with sunflower seeds and fitted with chip readers to measure bird feeder visits. labeled.
Scientists chose the tit because it is a small songbird (weighs less than half an ounce) that frequents bird feeders during the winter throughout its range; has high daily energy needs; and typically takes one seed on each feeder visit, allowing a clear measure of the feeder visit rate.
“This is an ideal species for evaluating how energy challenges lead to behavioral changes in the use of feeders during winter,” said Rivers. “Our study found that experimentally disabled chickadees, those with high flight costs, did not increase their feeder visit rate.”
Instead, the cut-feathered birds actually reduced their use of the feeders for a few weeks – perhaps to reduce exposure to predation – but after that they used the feeders at levels similar to the birds. uncut control birds. The researchers looked at the number of feeder visits, the number of feeders used, and the timing of feeder visits and found little difference between cut and uncut tits.
“Cut-feathered chickadees reducing their use of feeders compared to control birds suggest that foods in the environment – like seeds, berries and small invertebrates – were available enough to offset the increased costs of flight and allowed them to reduce the use of feeders, âRivers mentioned. âIt is clear that the tits in our study did not increase their visit rate or their dependence on additional foods during a time when they could have benefited the most. “
Janel Lajoie and Lisa Ganio collaborated with Rivers on the research. Lajoie graduated from OSU College of Forestry with a Masters and Ganio heads the Statistics Department at OSU College of Science.
The study was funded by the Department of Forest Ecosystems and Society and the College of Forestry at Oregon State University, with research supplies donated by Global Harvest Foods, Kay Home Products, and Perky-Pet, Inc.