Just like human beings, some birds like to hang out in groups, while others are more solitary in nature, coming together mainly to reproduce. A prime example of the latter group are the ruby-throated hummingbirds (Archilochus colubris).
This past summer, some health and other problems led to my spending a good deal of time at home. The upside was that being a bit home-bound gave me plenty of opportunities to observe the comings and goings of these gorgeous little flyers and to learn more about their behavior towards one another.
I had at least four ruby-throats – and probably more as I couldn’t distinguish them all – visiting my feeders and yard regularly. A couple had a distinctive trait that helped me identify them, like some white feathers on top of their heads or at the bottom part of their gorgets.
I usually had three or four nectar feeders up in my back yard and two in my front yard. In addition, as the summer progressed, the gardens were filled with increasing numbers of nectar-filled flowers so my home site was a fairly well-stocked larder for them.
The ruby-throats are among the more competitive hummingbirds and don’t really like to share their feeding space with others, although a friend and I visited a birder in a nearby town who had more than a dozen feeders up and many dozens of hummers visiting his back yard every day, feeding right next to one another. At my house, I suppose guarding their food source is an instinctual imperative, since they do consume half their own weight in nectar each day.
The tiny birds were quite intent on protecting their territory from intruders. Only thing was, several of them considered my feeders THEIR territory, so there was a continual rotation of birds perched in nearby trees and shrubs to watch for “invaders”. Once spotted, the newly arrived hummers would have the current “resident” bird swoop down on them (at up to 60 miles per hour!), frequently chittering like mad as a warning to “get out of here.”
Sometimes, they would have a little “challenge flight ballet” as they confronted one another, until one gave up and flew off – sometimes across the street, sometimes to the yard on the other side of the house, and sometimes to a nearby tree or shrub at the side of the house.
There was one particular male hummer who seemed particularly aggressive – or perhaps possessive is a better term as I never saw him body slam a rival; he just made sure that the other bird would leave. I recognized him as he often chose exactly the same spots on a nearby Rose of Sharon, a willow oak and a cedar as his watching posts,
Some of those who were run off didn’t travel far, however. They would fly to a nearby tree or shrub and wait to see if Hummer No. 1 would leave.
Scientists have determined that the brain section responsible for memory and learning – the hippocampus – is five times larger in hummingbirds than in woodpeckers, seabirds and songbirds. They memorize where feeders and nectar flowers are and can remember when they last fed there. They can even estimate how long it will take each flower to fill up with nectar again.
The hummers’ memory is long-term, too – they recall not only where feeders are placed in their breeding territories but also in places along their yearly migration routes! Wouldn’t it be nice if we had such great memories making GPS and maps less of a necessity?
Another behavior I observed several times was a hummer hovering in front of me, especially when the nectar feeders were getting low. Scientists have determined that they can recognize the people who replenish their food sources, which makes for a delightful encounter as one chirps at you while suspended in front of your face with its wings flapping at 60 beats per second!
While guarding their home turf, they may stick out their tongues briefly after feeding.
However, if you see one with its tongue stuck out permanently, this can be a sign of a fungal infection (often acquired from dirty feeders). Their tongues swell with the infection and they can no longer drink with these anatomical, elastic micro-pumps.
Often death ensues, so it’s important to keep the nectar feeders clean!
Coming up in part 2: the beauty of the hummingbirds at rest and in flight