by Rausa McManus, EMGV
If you’ve heard that you need to take your hummingbird feeders down in October to let hummingbirds know when to migrate, read further for another viewpoint. The idea that the availability of nectar in man-made feeders will keep hummingbirds from migrating south is a myth. Birds are genetically programmed to migrate due to their hormones, circannual rhythms, triggered by the length of the days and the changing angle of the sun. Leaving your feeders up with fresh nectar will help the late-migrating stragglers as they travel through North Carolina and also feed some winter-hardy hummingbirds who may live here year-round.
It can be difficult to identify hummingbirds by sight in the winter. However, banders have helped confirm the identification of certain species. The most common hummingbird species seen here in the Piedmont is the ruby-throated hummingbird (Archilochus colubris) (left photo). In recent years, however, volunteer banders have recorded rufous (Selasphorus rufus) (right photo), black-chinned (Archiloches alexander), and calliope (Selasphorus calliope) hummingbirds in the Carolinas during winter migration.
In order to keep the nectar edible for these winter feeders, the water to sugar ratio should be 4:1, with no food coloring. The nectar also needs to be changed every three to five days to keep it fresh. At this concentration, the liquid will not freeze unless the temperature gets below 27 degrees. Keeping your feeder full and fresh will help the late-migrators replenish their energy stores so they need to make it to their southern destination.
There are many researchers interested in collecting data on winter-migrating hummingbirds. If you do see hummers visiting your feeders between November 1 and March 15, make a record of the type and number of the birds you see. The North Carolina Museum of Sciences is studying hummingbirds that overwinter in the Carolinas. They would like to hear from Piedmont residents who spot these little hummers and they encourage you to leave those feeders up through the cold months.
Photo Credits: Ruby-throated hummingbird (Archilochus colubris) by Bill Gordon/Great Backyard Bird Count at audobon.org. Rufous hummingbird (Selasphorus rufus) at naturalsciences.org https://creativecommons.org/licenses/by/4.0/ Other photos by R. McManus.
Resources and Further Reading