(by Rebecca Suomala, September 2023)
If your birds disappeared from your feeders at the beginning of September, you are not alone. NH Audubon has received many inquiries from people whose feeders went quiet about this time. There are no known disease outbreaks affecting songbirds at present and the disappearance of the birds is likely related to migration and natural food supplies.
In the fall, there is often a period of time when our migrant birds have left but our year-round resident birds haven’t come in to feeders yet, and migrants from farther north haven’t arrived. Species that spend the winter in the tropics such as Rose-breasted Grosbeaks are triggered to migrate by the changing day length. They begin migrating as early as the beginning of August.
For our resident birds, there’s a phenomenon called “post-breeding dispersal” which happens at this time of year, in which our breeding birds (young and adults) gather in mixed flocks (more than one species) that sort of wander around, which is wonderful when you find one, but can leave other areas relatively lacking in birds.
The rains of summer have resulted in an excellent crop of natural foods including berries and seeds. In addition, the White Pines are laden with a cone crop that is just starting to open and release the seeds which many bird species eat, such as chickadees and nuthatches. Resident birds will take advantage of this bounty of food that is just becoming available.
If you have fewer birds, please don’t worry – it has nothing to do with your feeders. The beginning of September was exceptionally warm and we’ve had no real cold weather yet. During mild weather in the fall and winter, natural food sources are more plentiful and birds spend more time in the woods, often ignoring feeders entirely. The mild weather this September combined with the excellent natural food supplies has probably exacerbated the absence of birds at feeders. When temperatures fall and natural food supplies decrease, birds will return to feeders.
In some years, poor weather during the summer makes it difficult for adult birds to successfully raise young. There may be fewer young birds around, resulting in a smaller quantity overall of our songbirds. We don’t have the data to evaluate any impacts from this summer’s rain storms but anecdotal reports indicate at least some species fared very well. There is no indication from NH Fish & Game that avian flu is impacting songbird populations. Although mortality in small birds can be difficult to detect, the recent strain of avian flu appears to have impacted colonial nesting birds such as gulls, waterfowl, and birds that feed on them.
In cold and stormy weather, the birds come to feeders more often, so be patient. We encourage you to report the activity at your feeders, or lack thereof, in our annual Backyard Winter Bird Survey in February. Check the website for more information or to be added to the mailing list and receive the survey materials email us.