Out My Backdoor: Hummingbird Predation

Black diamond headed rat snake is curled around a red hummingbird feeder.
Rat Snake on a Hummingbird Feeder by Terry W Johnson

 

By Terry W. Johnson

Predators catch and eat prey in our backyards every day. Typically, when we witness predators catching prey, it takes the form of something like Fowler’s toads catching small moths below our outside lights, spiders scampering across their webs to subdue flies ensnared in their sticky webs or bluebirds nabbing winged termites as they emerge from a rotting stump. We usually do not find these scenes upsetting.  

However, when a Cooper’s hawk flashes across your yard and snatches a house finch at a feeder, we often tend to find this true-life drama a little unsettling.

In the minds of many, spotting a rat snake draped across a hummingbird feeder and holding a hummingbird in its mouth would be even more unnerving. Yet, after watching hummingbirds for decades, my wife Donna and I recently saw that for the first time.

One of the first things we enjoy doing each morning is watching the hummingbirds visiting our feeders and flowers. A couple of weeks ago when I stepped out the backdoor on a typical warm, humid summer morning, I spotted a dark object on the back of one of the feeders. My first impression was it was a bat.

However, when I walked closer it became apparent that the animal was a young rat snake.  In fact, the snake was so small (roughly, 3 feet long), its weight did not tilt the feeder.

I immediately called to my wife, urging here to grab a camera and come see this interloper. After she joined me, we inched closer to the snake trying to find just the right spot to better see what was going on. At first the snake remained motionless. Finally, when it moved its head away from the perch encircling the feeder’s feeding ports we saw that it had a hummingbird in its gaping mouth. All we could see of the hapless bird was a bit of its green back, one wing, and a leg. As we watched spellbound within 10 minutes or so, the bird disappeared completely.

Wow! As soon as the bird finished swallowing the hummingbird, it made no effort to leave. In fact, it even allowed me to carry it and the feeder to the far reaches of my yard where I released it.

A surprising number of animals prey on hummingbirds. It might seem odd to find that snakes do not top that list. Some hummingbird experts rank cats as the main hummingbird predator in the U.S.

If that comes as a surprise, you might raise your eyebrows a little higher when I tell you that second place goes to the Chinese mantis. This exotic species, released in Pennsylvania in 1896, is the behemoth of the mantis world, measuring up to 5 inches long.

Large dragonflies have long been suspected to be hummingbird predators. A few years ago, this theory was finally corroborated: At least one dragonfly species known as the common green darner does apparently prey on hummingbirds. It seems a birder photographed one of these large dragonflies dining on a hummingbird while perched atop a picnic table in Port Arthur, Texas.

Robber flies are among the most voracious predators that inhabit our backyards. Yet most of these insects are too small to attack a hummingbird. However, some say that larger species are capable of capturing and eating a hummer.

Hummingbirds sometimes become entangled in spider webs, particularly those fashioned by orb-weavers. The spread of the alien Joro spider throughout north Georgia has raised the concern of hummingbird fanciers that hummingbirds will become entrapped by this large spider’s huge, sticky webs. Although hummingbirds snared in webs often die, I am not aware of any evidence that suggests spiders actually eat ruby-throated hummingbirds in the Peach State. That being said, some large South American spiders are known to prey on hummingbirds.

The only fish thought to be a potential hummingbird predator is the largemouth bass. On rare occasions, hummingbirds have even been found in the stomachs of this popular game fish. (I wonder if a lure imitating a hummingbird has ever been marketed?)

Large frogs also will catch hummingbirds. In Georgia, frogs such as the bullfrog are big enough to eat a hummingbird.

Georgia’s lizards do not pose any danger to hummingbirds. But that’s not the case outside of the U.S., where lizards and snakes pose serious threats.

About a year ago, a homeowner living in southern Mexico responded to a blog that appeared in the TERN-sponsored blog backyardwildlifeconnection, which I write. The homeowner said that a large lizard named the Mexican spiny-tailed iguana eats hummingbirds at their feeders.

The person went on to say that a pair of ferruginous pigmy-owls has been living in a tree growing near their house. However, ever since the owls fledged two young from a nest in the tree, the owls had been seen taking more than 10 hummingbirds.

A number of birds prey on hummingbirds. Small hawks such as the northern kestrel and the sharp-shinned and Cooper’s hawk are the species most likely to catch a hummingbird.

Several years ago, a woman living in St. Marys told me about seeing a small hawk that she thought was an American kestrel catch a hummingbird flying across her backyard. It seems that while convalescing with a broken leg, she spent considerable time watching the hummingbirds feeding in her yard. One late-summer day, as she was enjoying the birds’ aerial acrobatics, she noticed a rotund hummingbird (apparently laden with fat to fuel its fall migration) flying near a feeder. Seemingly out of nowhere, the small hawk swooped in, grabbed the ruby-throat and quickly vanished.

Some of the more unusual avian predators include owls, grackles, blue jays, herons, tanagers, loggerhead shrikes and even gulls.

If that lineup of potential predators is not enough, the venom in bee and wasp stings can kill hummingbirds. Of course, as you might imagine, they cannot eat hummers.

Predation is going on in our yards 24-7. It is an integral part of nature. For example, biologists estimate that some 96 percent of all terrestrial birds eat insects at some time during their lives.

However, since most of it takes place out of sight, we tend to blot it out of our minds. But when you do think about it, even hummingbirds are predators: They regularly eat tiny spiders and small insects. Focusing on this fact, and the realization that snake predation on rubythroats is rare, should make it easier if you do have the rare opportunity to see a snake

Terry W. Johnson is a retired Nongame program manager with the Wildlife Resources Division and executive director of The Environmental Resources Network, or TERN, friends group of the division’s Nongame Conservation Section. (Permission is required to reprint this column.) Learn more about TERN, see previous “Out My Backdoor” columns, read Terry’s Backyard Wildlife Connection blog and check out his latest book, A Journey of Discovery: Monroe County Outdoors.”