Killer hummingbirds revisited


“It’s a photo of a dead hummingbird! What do you make of it Holmes?”
“Impossible to say without additional evidence, Watson.”

Periodically over the nearly nine years since the publication of Killer hummingbirds?, I’ve received comments from people taking issue with what they believe that post says. Typically, these readers have witnessed an attack by one or more hummingbirds on another and wish to inform me that I’m wrong to say that hummingbirds never kill each other. The first problem is that I didn’t say “never,” and they would know this had they read as far as the bold black text in the middle of the post:

 “Only birds weakened by hunger, disease, or injuries… are vulnerable to injury and, in rare instances, death from other hummingbirds…”

Some of the reports clearly fit the qualification above, because, to quote more of the original post:

a healthy hummingbird will either defend itself or flee before a more aggressive individual gets the chance to do any significant damage.

Others provide few if any useful details of the event, even when prompted, and still others are just accounts of finding a dead hummingbird and assuming, because they had previously observed combat, that it was a case of trochilicide.

This brings us to the other problem with these reports, which is that they are never accompanied by any objective evidence—photos or video—that would support their accounts of the events (much like reports of yellow hummingbirds). A recent correspondent claimed to have seen a Black-chinned Hummingbird…

“…physically stick his bill deeply into another h.bird’s belly, twice! Then 2 more times into the back of the others neck.”

There are a couple of problems with this description as evidence of hummingbirds fighting to the death, even if one combatant is severely disadvantaged. The first is that poking is rather common in hummingbird combat, and the disappearance of the tip of an aggressor’s bill into the thick plumage of the “victim” would be understandably alarming to someone unfamiliar with hummingbird anatomy.


A hummingbird poking another’s body with its bill is a bit like someone poking Marie Antoinette in the bouffant with a knitting needle.

The second is that, even when the bill passes completely through the feathers and makes contact with the other bird’s body, hummingbird anatomy makes a fatal penetrating wound highly unlikely except in freak circumstances (see page 23 of A Field Guide to Hummingbirds of North America for an example).

This X-ray CT image of a Ruby-throated Hummingbird, showing its huge, deeply muscled rib cage, short skin-and-bones neck, and virtually nonexistent “belly,” demonstrates why hummingbirds are not as vulnerable to penetrating wounds as humans are (or as capable of inflicting them):

CT scan of a Ruby-throated Hummingbird. Copyright

CT scan of a Ruby-throated Hummingbird. Copyright

The issue of hummingbirds injuring one another in combat took a fascinating twist in 2014, when Alejandro Rico-Guevara of the University of Connecticut and and Marcelo Araya-Salas of New Mexico State University announced their discovery that the unusual bill shapes of adult male Long-billed Hermits make them more effective at inflicting potentially painful puncture wounds than the bills of females and juvenile males, and that males with longer, pointier bill tips were more successful at defending territories.

These revelations were newsworthy precisely because the bill shapes of the vast majority of hummingbird species, including all of the familiar North American species, show no such adaptations and confer no apparent advantages in combat. It’s also noteworthy that while the researchers observed male Long-billed Hermits poking each other during combat, they did not mention observing any serious injuries, much less fatal ones, resulting from these interactions. In fact, most of the “fighting” shown in their video consists of belligerent posturing and vocalizing with little physical contact, similar to the combat behavior of most North American hummingbirds:

(Note that the black-and-white segment depicts two non-hermit species, and the last sequence depicts courtship and mating, not fighting.)

So now we have compelling evidence that males of at least one hummingbird species have bills adapted for use as “stabbing” weapons, yet documentation of fatal encounters between healthy, normal hummingbirds is still almost as elusive as Bigfoot. I expect it will remain so, but I’m open to persuasive evidence.
Decreux LikenessesResources:

Rico-Guevara, Alejandro, and Marcelo Araya-Salasb , 2014. Bills as daggers? A test for sexually dimorphic weapons in a lekking hummingbird. Behavioral Ecology 26(1): 21-29. Archilochus colubris, Ruby-throated Hummingbird by Dr. Ronald Stearman, The University of Texas at Austin.

New post at my Web site


I’m such a bad blogger. I didn’t even post about my spectacular trip to Trinidad and Tobago last summer where I photographed this stunning White-necked Jacobin.

Has it really been almost a year since I last posted here? I’m still working on the second edition of A Field Guide to Hummingbirds of North America, so I haven’t been doing much writing otherwise, but I did just add a post to the News tab on my Web site about a controversy that erupted during the spring 2012 Ruby-throated Hummingbird migration. Hope you enjoy it!

P.S.: If you’d like to see more of my photos from Trinidad and Tobago, check out the album on Flickr.

Search of the Week: “what can I feed hummingbirds to get them protein”


Sugar water is a substitute for the nectars of hummingbird-pollinated flowers, which provide the birds with energy-rich sugars, water, some electrolyte salts, and little else. Almost everything else their bodies need, including protein, comes from eating insects, spiders, and other small arthropods. (Salvia sp. in my garden, copyright S. L. Williamson)

Hummingbirds do need extra protein in their diets during the nesting and molting seasons. Here are some tips for helping them meet their protein needs:

  • Don’t use broad-spectrum pesticides in your yard: Many common yard and garden pests, including aphids, whiteflies, and various annoying gnats and midges, are just the right size for hummingbirds to eat. Even if the birds don’t sicken and die from eating poisoned prey, spraying pesticides destroys an essential source of natural nutrition and makes your yard less attractive to them. Switch to targeted, low-risk remedies for specific pests, such as a hard spray of water under leaves for aphids and various forms of the natural pest pathogen “Bt” (Bacillus thuringiensis) for caterpillars and mosquitoes. Also, beware of purchasing hummingbird flowers from mainstream garden centers. Many of these plants have been unnecessarily treated with the same neonicotinoid pesticides that have been implicated in the terrifying declines of honeybees, native pollinators, and native insect-eating birds.
  • Cultivate a compost pile: Fruit flies are attracted to decaying vegetable matter, including fruit rinds and scraps. Garden experts often advise against adding fruit to compost piles/bins in part to discourage fruit flies, but these tiny insects provide excellent hummingbird food while aiding the composting process.
  • Grow your own fruit flies: There are lots of recipes on the Web. When a culture matures, just set the container in your garden and open it so the flies can escape.

The one thing you absolutely, positively should never, ever do is add protein supplements to your feeder solution. It’s unnatural, the solution will spoil much faster, and the birds will not like the taste. (Captive hummingbirds drink protein-rich liquid diets, but only because they have no choice. They’d much prefer flower nectar or sugar water for energy and water and a variety of insects and spiders for protein, amino acids, vitamins, minerals, etc.)

More on what to put (and not put) in your hummingbird feeder:

Feeder Solution Evolution, Part I: The Basics
Search of the Week: “is molasses ok to feed hummingbirds”
Feeding Hummingbirds: The dangers of red dye
Beet juice in hummingbird feeders: NO!
Search of the Week: “hummingbirds won’t eat instant nectar”
Search Roundup: Feeding hummingbirds
Keeping hummingbird feeders clean


New post at my Web site

Wire-crested Thorntail, Ecuador

Wire-crested Thorntail, Ecuador

As work progresses on the revision of A Field Guide to Hummingbirds of North America, I’ll be using the News page at my Web site to post updates, previews, and other items of interest to users of the guide and other fans of hummingbirds. The first post is about providing nesting material for hummingbirds, one of many new and expanded topics covered in the second edition of the guide.

The Life, Birds, and Everything blog will remain here at, at least for the time being, so please enjoy the archives. Thanks for following along!

“Chemical-free” sugar?

My reply to the following e-mail bounced, so I’ll answer it here:

I’ve read the first part of your article on hummingbirds about what  to make when you feed them.

Before reading the article, I just made hummingbird food with organic sugar. I am concerned about the addictive and other chemicals in white sugar. Is there any white sugar available on the market that does not contain chemicals?  or a way to transform organic sugar in white?

Thank you for your time.

In the strictest sense, there is no product of any kind on the market that doesn’t contain chemicals. I’ll need to know what specific substances you’re concerned about (other than iron) before I can answer your question, but the way it’s phrased suggests that you may have fallen victim to fear-mongering hyperbole about white sugar. In that case, this post may be helpful:

Search of the Week: “if refined sugar is so bad for us then why do we feed it to hummingbirds??”

One feederful of organic sugar isn’t going to kill hummingbirds because the iron concentration is very low. It’s chronic exposure to excess iron over weeks, months, or years that may cause illness and death. Unfortunately, there is no simple home remedy for removing the residual iron from organic/”raw”/turbinado sugar.

Search of the Week: “it is september why am i only getting female hummingbirds at my feeders…”

In juvenile plumage, young male hummingbirds like this Ruby-throated usually look a lot like their mothers. They also seem to leave the nest with chips on their shoulders.

In juvenile plumage, young male hummingbirds like this Ruby-throated usually look a lot like their mothers. They also seem to leave the nest with chips on their shoulders.

The full search was: “it is september why am i only getting female hummingbirds at my feeders and she is very aggressive”

By September, most of the migratory hummingbirds remaining at northern latitudes will be young birds of both sexes, which look like adult females except for variable amounts of pale fringing on the iridescent feathers of their backs and heads (plus a few other subtle differences, depending on species). Young males often show lines of dark spots on the throat, a pattern hummingbirders call “five-o’clock shadow.” Some young males will show bright flashes of color in their gorgets as adult feathers replace drab juvenile ones.

Though females of any age can be very aggressive and territorial, especially in migration, it’s the young males that seem to be the biggest troublemakers (as though they think they have something to prove). As long as there are still good numbers of hummingbirds around, expect the screeching, chasing, grappling, and chest-bumping to continue.

Keeping hummingbird feeders clean

Hummingbird Feeder Cleaning Kit

Brushtech Hummingbird Feeder Cleaning Kit at (click image)

If you’re like me, you’ve got a collection of toothbrushes, baby bottle brushes, and even well-washed mascara brushes sitting next to your kitchen sink for cleaning hummingbird feeders. The problem is that tools made for other cleaning jobs don’t always work as well for such a specialized task, so it’s nice to see a set of brushes made especially to reach the nooks and crannies of typical hummingbird feeders. The big brush in this set could even get into the enclosed bases of some of the cheapo feeder models to remove crud you can’t see.

Of all the nasties that grow on hummingbird feeders, the nastiest and hardest to control is black mold. A 15-minute soak in a dilute solution of chlorine bleach*⇓ (1 part bleach in 10 or more parts water) is very effective at killing black mold on non-porous surfaces, but an hour-long soak in white vinegar is a less toxic alternative (NEVER use bleach and vinegar together: you could kill yourself!). In either case, follow up the soak with a thorough brushing to remove dead mold colonies and other organic growths, then rinse well and let the feeder dry before refilling to allow the odor to dissipate.

An even safer mold killer that’s much kinder to your nose than bleach or vinegar is 3% hydrogen peroxide, the medicinal kind you can buy in any drug or grocery store. The downside is that it’s much more expensive than bleach or vinegar. A frugal alternative to traditional soaking is to add a couple of ounces to the feeder bottle, screw on the base, invert the feeder and swirl gently over a sink or bucket to make sure the peroxide covers all inside surfaces, then allow it to stand for at least 10 minutes. While the peroxide is doing its work from the inside, spray the outside with more peroxide to kill any mold growing there. Follow the treatment with a good scrub, including the ports. and rinse well to remove any debris. No drying needed; the peroxide will leave no odor, and the only residues are water and oxygen.

This advice applies mainly to bottle-style feeders. Saucer feeders such as the Aspects Hummzingers can be cleaned by hand using dish detergent and the small port brush in the kit above or washed on the top rack of the dishwasher. If any stubborn debris accumulates in the built-in ant moat, the little ball-shaped brush in the Brushtech set will swish it away.

Regardless of what type of feeder you have, it will need cleaning and refilling every 1 to 3 days in hot, windy, and/or rainy weather and every 4 to 6 days in cooler, calmer, drier weather, whether the birds have emptied it or not. If you can’t make a commitment to good feeder hygiene, it’s best to plant flowers instead.

* There’s a persistent myth that using chlorine bleach to clean feeders will kill hummingbirds. It won’t as long as you rinse the feeder well, just as you would if using bleach to disinfect your own dishes or your pets’ dishes. Any minute traces of chlorine residue will be rendered harmless by reacting with the sugar in the feeder solution (the same thing happens when you mix sugar with chlorinated tap water).