Archive | May 2022
BACKYARD SECRET—THE RUBY-THROATED HUMMINGBIRD’S BRAIN IS BIGGER THAN YOU THINK
I am truly amazed at the ruby-throated hummingbird’s memory. For example, studies have revealed rubythroats can remember the locations of every feeder and flower they visit in our yards as well as how long it takes each flower to replenish its supply of nectar. They can even remember the locations of the feeders and flower beds that provided them with food the previous year.
Wow! It must take a truly large brain to accomplish such mental fetes. In truth, the rubythroat’s brain is smaller than a pea. While that is indeed physically very small, comparatively speaking it is larger than our brains or those of any other bird in the entire world. Let me explain.
The hummingbird brain makes up about 4.2 percent of its body weight. This makes its brain is proportionally larger than the brains of all other birds. In comparison, our brains comprise only about 2 percent of our body weight.
LOOK FOR BEGGING AT YOUR FEEDERS
At this time of the year, it is common for adult birds to appear at our feeders accompanied by their fledglings. When this happens, we are able to observe the young begging for their parents to feed them.
The fledglings’ parents have been feeding their young in the nest for quite some time. Interestingly, once their brood leaves the nest the adults will continue to feed young birds for anywhere from one to three weeks. During this time the young birds will make their first attempts to feed themselves. However, most fledglings would undoubtedly starve if their parents did not continue to feed them.
When a family of birds arrives at your feeding station the youngsters will sometimes perch atop or nearby a feeder waiting for a parent to feed it. However, it seems that more often than not a fledgling will perch alongside a parent that is dining on seeds or other foods. In an attempt to coax a parent to feed it, a fledgling will typically anxiously chirp at an adult while rapidly fluttering its wings. This usually does the trick and the parents succumb to their youngsters begging.
This morning I watched a family of house finches arrive at one of my sunflower feeders. Immediately the fluffy, drab youngsters began begging for food. Their irritating behavior worked and quickly the parents were placing food in the large, gaping mouths of their young.
As I watched this fascinating behavior, I said to myself, “Little guys, you had better enjoy the free lunch while you can as it won’t be long before you will be fending for yourselves.”
BACKYARD SECRET—ORCHARD ORIOLES OFTEN NEST CLOSE TO EASTERN KINGBIRD NESTS
For reasons that are not fully understood, some orchard orioles will nest close to the nests of eastern kingbirds. This might come as a surprise since eastern kingbirds have the reputation of aggressively defending their nests. Well, many experts believe that this is the reason why orchard orioles will choose nest sites sometimes within mere yards from the nests of eastern kingbirds.
It seems obvious that kingbirds do not feel threatened by North America’s smallest oriole. However, when kingbirds fly out to confront a crow, common grackle or other potential avian nest predator flying close to their nests, they unwittingly also defend the nearby nests of orchard orioles.
Some studies suggest that this behavior may translate into real benefits for the orchard orioles. Studies have shown that, when the nesting success of orchard orioles that nest close to eastern kingbirds was compared with the success of those that do not, they discovered the nesting success of orioles that nest some distance away from eastern kingbird nests was lower. In fact, there also seems to be a correlation between kingbird populations and orchard oriole populations. When eastern kingbird numbers are high orchard orioles are more abundant too.