Posted by: Sheri | August 29, 2007

Killer hummingbirds?

Well, blogging being the inbred activity that it is, I’m starting off by tackling the well-intentioned comments of another blogger. A post to the Hummingbird Forum on Network 54 alerted me to a post at Robin’s Nesting Place in which “Robin” blames feeders for an attack on a weakened hummingbird by a healthy territorial one. She wrote:

It isn’t worth it for me to have a feeder if it causes the hummingbirds to be so violent with each other…

Using feeders is a wholly personal choice, but I hate to see someone become upset – and upset others – over a misinterpretation. In a follow-up post, Robin described hummingbirds “fighting to kill” as “unexpected behavior”:

I thought they were just cute little interesting birds and had this sweet image of them in my mind. It was a shock for me to witness such unexpected violence.

As my husband says, people who describe hummingbirds as “cute”and “sweet” haven’t been paying attention. But a lot of people share this misconception, and shedding it is a significant step in Robin’s growth as a gardener and observer of nature. Unfortunately, her horror has pushed her a bit far the opposite direction, leading her to believe that hummingbirds routinely fight to the death over feeders. As proof, she linked to another gardener’s blog with a photo of a hummingbird at a feeder, supposedly bloodied from a fight.

Hummingbirds are definitely more Taz than Tinker Bell, but (thankfully) they just don’t have what it takes to commit trochilicide. Even if that wicked-looking bill wasn’t too fragile and sensitive to be an effective weapon, its wielder couldn’t muster enough force to fatally pierce the body of another bird without risking its own life. Even the most vicious fight seldom does more than dislodge a few feathers. That photo in the other blog? A juvenile male Ruby-throated acquiring his red gorget feathers, not a bloody female. I’ve watched tens of thousands of hummingbirds feeding and fighting and never, ever seen a bloody one.

The fact is that a healthy hummingbird will either defend itself or flee before a more aggressive individual gets the chance to do any significant damage. Only birds weakened by hunger, disease, or injuries (from encounters with cats, windows, cars, and power lines, for example) are vulnerable to injury and, in rare instances, death from other hummingbirds, but these disadvantaged birds are far more at risk from cats, larger birds, and other predators. A starving, sick, or injured hummingbird is going to gravitate toward the easiest and most reliable energy source – a feeder – which makes one-sided battles such as the one Robin witnessed more likely to be observed at feeders. But it’s not the feeders’ fault, and their accessibility may mean the difference between life and death for those disadvantaged birds – a quick energy boost that gives them the strength to fight back or flee.

If feeders made hummingbirds fight to the death, imagine the carnage at our famous hummingbird feeding stations here in Arizona, some of which have dozens of feeders and host literally thousands of hummingbirds per day in migration. With one of our most combative hummingbirds, the Blue-throated, being three to four times the size of most of its rivals, the ground under the feeders would be littered with corpses. Needless to say, this doesn’t happen, despite frequent savage battles, or these feeding stations would have been closed years ago.

The implication in Robin’s original post, clarified in the comments that followed, was that hummingbirds don’t fight over flowers. Ha! If hummingbirds aren’t fighting over her flowers, she needs to plant better flowers. The richer the nectar source, the more it’s worth fighting over, so I’m guessing that Robin’s garden doesn’t include a really spectacular nectar producer. My own garden is mostly hummingbird flowers, but neither my “tame” flowers nor my feeders can compete with the wild agaves that grow nearby. Even though the numbers of migrants have been increasingly daily, our feeders have been virtually abandoned for the last couple of weeks (except following heavy rains). Instead, the birds are jousting and bickering with each other over the agave flowers.

So what can a sensitive, peace-loving soul do to foster détente in the feeder wars? Try adding more feeders and moving them further apart, preferably out of sight of one another. This won’t keep them from fighting, but it’ll give more birds a chance to feed undisturbed.


Responses

  1. I was just idly googling to see if anyone else has used the word “trochilicide” and I found this blog entry. Certainly it’s rare, but there is one apparent example: http://www.carolinabirdclub.org/gallery/trochilicide.html

  2. Actually, that’s more likely to be a case of a courtship display gone horribly wrong. Males of the “flame-throated” hummingbirds (a group of small species in which adult males have brilliantly iridescent throat patches) do spectacular aerial dive displays that function in both courtship and territoriality. Near the bottom of the arc or loop they’re pulling some serious Gs, and a collision with another bird at that point would almost certainly be mutually fatal. That’s what appears to have happened here, and there’s a photo of similar example in my field guide involving two male Broad-tailed Hummingbirds.

  3. My wife witnessed trochilicide today at one our feeders. A female rufous hummingbird was attacked by a pair of ruby throated hummingbirds. The hummer got caught in the feeder and was savaged by her attackers before my wife could intervene. We extricated the hummer from the feeder, gave her some nectar, and took her to Avian Rescue, where she expired.

  4. Thanks for the interesting (though sad) report, Fred. Your description of this unnatural event raises several questions, some of which I realize may be difficult to answer but all of which have a bearing on evaluating the role the bird’s attackers played in her demise:

    How long was the bird trapped?

    What was her condition before she was attacked?

    What injuries did she receive in the attack? Did Avian Rescue examine the bird postmortem and document her injuries?

    How exactly did she get caught in the feeder?

    Is there a possibility her post-attack condition was complicated by human handling? I ask not in an accusatory way, but because I’ve seen even people experienced in handling small songbirds kill hummingbirds by holding them the wrong way.

    As I noted in the original post, hummingbird-on-hummingbird violence seldom results on more than a few dislodged feathers unless the victim is weak, sick, or otherwise at a disadvantage. Ultimately, the dangerous design flaw in the feeder that prevented this bird from fleeing or fighting back is what killed her, and, had she been unable to extricate herself, it would have killed her even if she hadn’t been attacked. I would recommend tossing out that feeder and reporting this incident to the manufacturer so that they can address the design flaw and keep other hummingbirds from dying.

  5. I have been feeding my little buddies for a long timeand I have never seen these duels to the death. There are some territorial spats but nothing as dramatic as what has been reported! The little guys have turned into tiny falcons. It must be the ozone !!!!!!!!!!!

  6. We’ve just found two male bodies side by side near the feeder where earlier today they were doing constant battle, even though we have two feeders, one at a bit of a distance away from the other.

  7. Is the feeder where you found the bodies near a window? Territorial behavior increases the risk of fatal window collisions by distracting both the chaser and chasee. To reduce the risk of fatal collisions, place the feeders either less than 2 feet or more than 30 feet from any window or glass door. (More window safety advice from FLAP.) To moderate the fighting, try moving the feeders far enough apart that it’s difficult for one bird to defend them both.

    • No, it’s not anywhere near a window. It’s hanging from a tree, not at all close to the house. But, I can see how that would happen.

  8. [...] Hummingbirds don’t fight to the death, at least not intentionally. Dead hummingbirds can’t mate, and that’s the whole point of this kind of territoriality. [...]

  9. My husband and myself have been hanging hummingbird feeders for decades, 5 large ones at busy times, 2 when things are slow as they have been so far this summer. We’ve witnessed all of the usual displays, etc. Today, we saw what we initially thought were 2 hummers mating on the feeder. Upon closer inspection a male ruby throated was sitting on the back of a female and he was repeatedly stabbing the back of her neck with his bill and ripping out feathers, she was a bloody mess. We went out there and the male RELUCTANTLY flew away, as we neared the hurt female she did fly off, but it was very erratic and low to the ground into the woods. I suspect she’s dead by now but it was quite disturbing to watch (as nature often is) and we had never witnessed this type of violence before. I found this blog by searching out any information on this type of behavior.

    • Thanks for sharing this very unusual (and grisly) sighting. There’s something horribly wrong with a hummingbird that doesn’t either defend itself or flee from an aggressor. Considering how deep the wounds would have to be to produce the amount of blood you describe, it’s likely that the victim (which could have been either an adult female or a juvenile of either sex) had been attacked by something else (a cat, larger bird, praying mantid, etc.) and was too weakened by its injuries to fend off the male hummingbird’s attack. As for the male’s behavior, it suggests normal territorial aggression escalating when the intruder failed to respond normally. The sight of blood is known to provoke attacks in other animals, but as far as I know this phenomenon is unknown in hummingbirds (though of course they do associate red with food sources).

  10. [...] July 18, 2010 Sick Hummingbirds Posted by Kay LittleJohn under Uncategorized Leave a Comment  We have two hummingbird feeders hanging up on our porch.  We love watching these beautiful little creators.  They are so tiny, fast, aggressive, and beautiful.  They are like little warriors at times.  Injuries are rare though.  We have never witness an injury yet and have had our feeders up for about 10 years.  There is a good blog post about the aggression (which is really the hummingbirds being territorial) in hummingbirds.  You can read this blog post at:  Killer Humming Birds.  [...]

  11. I live in Charlotte, NC and have been feeding the hummers for years. The other day I witnessed something I hope never to see again. Two hummers were following an obviously distressed hummer and pecking him/her in the back of the head. I broke up the fight several times and was even able to touch the injured little critter. Finally they left and didn’t come back that evening. The next morning I found the hummingbird dead, on the ground under the feeders with a hole in the back of its head and both eyes missing.
    I have read comments from people saying this kind of behavior doesn’t or can’t happen, that is not correct since I saw it. Their little beaks are strong enough to do serious damage and they certainly have the aggression. I seriously considered taking the feeders down after this. I have started calling them the nectar cartel in reference to the mexican drug cartels wreaking havoc along the border.

    • *sigh*

      Yes, it does happen, Dewey, and in exactly the sort of situation you’re describing. I stated this very clearly in the post, which you don’t seem to have read. Quoting paragraph #5:

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

      In fairness to the “cartel,” though, it’s highly unlikely that any of them are responsible for a hole in the skull (I assume you mean the skull and not just the skin) for reasons I also outlined in the post. That long, narrow bill, with its thin sheath of keratin and core of fragile, living bone, is adapted for probing flowers, not for stabbing. In fights it can be used to poke, possibly tearing the thin skin of another hummingbird and even bruising the underlying tissues (or to damage to the eyes, though I’ve never witnessed such a thing and very rarely see eye injuries in the birds I band), but it has neither the shape nor the strength to create a mortal wound in even soft tissues, much less the skull, without serious risk of life-threatening injury to the aggressor. My confidence about this comes from handling thousands of live hummingbirds (which don’t stab or poke me in self-defense) and hundreds of museum specimens and spending thousands of hours observing their behavior.

      You admit that you didn’t witness the bird’s death, so you can’t know for certain what caused the damage to the skull (if it was the skull and not just the skin). Many other bird species that have short, strong bills adapted for making holes in things would also be likely to attack a sick or injured hummingbird. Hummingbirds dessicate quickly, and if you didn’t see bloody eye sockets the eyes were most likely simply sunken into the head (though eyes are often the first target for scavengers such as ants). The other hummingbirds could certainly be responsible for damage to the skin on the back of the head, but it would take careful measurement of a hole in the skull to determine if the wound could have been caused by another hummingbird.

      And I must strongly re-emphasize the main point of the article, too: Feeders don’t cause unnatural levels of aggression. They do tend to attract vulnerable birds, increasing the chances of someone seeing scenes such as you described, but their net impact on weak, sick birds is almost certainly positive (at least in the short term, since many of these birds have problems from which they will not be able to recover).

      If you want to take your feeders down because you don’t like hummingbirds anymore, that’s a justifiable decision, but it won’t stop the warfare or prevent any deaths. Whether you take down your feeders or not, I suggest you do some sleuthing for ways the dead bird may have gotten into that vulnerable state: a dirty feeder, an unscreened window, pesticides sprayed on your lawn or flowers, etc. Its condition may be unrelated to any hazards in your yard, but if it was it could happen there again whether you take down your feeders or not.

  12. Dewey,
    It is a horrible sight, but I wouldn’t take the feeders down. They are territorial, but they would be territorial over the flowers also. We’ve been feeding them for decades as I’ve stated and have only witnessed this behavior (for whatever reason) once. Nature is what it is. We still continue to hang the feeders, feed the little buggers and enjoy the show.

  13. [...] is attracted to your eyes, but not because it intends to puncture them with its needle-shaped bill (which is more like a straw than a stiletto). Many animals instinctively associate large, forward-facing eyes with predators, and hummingbirds, [...]

  14. [...] Killer hummingbirds? Search of the Week: “hummingbird attack eyes” [...]

  15. Lat yesterday afternoon, we witnessed one hummingbird attack another hummingbird that was feeding on some honeysuckle flowers near our back door. The victim looked like it might be a juvenile, with a lot of downy feathers on its underside. The attacker got on the back of the feeding bird, and definitely stabbed at it several times before the feeding bird finally flew away. The attacked bird then landed on the very nearby canopy over our back door and rested. Its feathers were sort of flattened out and dissheveled. After a few minutes, it flew away. It may have been sick, as we had noticed earlier that it looked like it was breathing heavily when it would stop sipping and perch. This morning we found it dead on the ground with what looked like blood on the side of its neck. Perhaps hummingbirds can’t hurt each other with their beaks, but it sure appeared like the dead bird had a bloody puncture wound on its neck, and was otherwise intact. For a few weeks, we have regularly seen a small slim hummingbird, that looks just like the attacker, perching in a small twigged tree across the walk from the honeysuckle. Do you think the dead bird accidently crashed into a hypodermic syringe, or encountered a predator that changed its mind after wounding the bird?

    • ~whoosh~ That’s the sound of this post’s point whizzing past your head, Allen. Maybe you should consider channeling some of the energy you use for sarcasm into reading comprehension.

      The post emphatically states, and the reply to Dewey Kiley’s similar comment reiterates: “Only birds weakened by hunger, disease, or injuries… are vulnerable to injury and, in rare instances, death from other hummingbirds…” My pinkies are too fragile and sensitive to be effective weapons, but that doesn’t mean I couldn’t poke someone’s eyeballs out with them under the right circumstances—say, if the victim was weakened by hunger, disease, or injuries or stupefied by one too many appletinis. In some freakishly rare instance, I might even be able to kill someone with my pinkies. If the encounter you observed actually resulted in the death of the bird you found later, you can chalk it up to one of those rare instances prominently mentioned in the post. It is by no means certain that it did, however.

      Among the 6000+ hummingbirds I’ve handled as a bander, I’ve seen a variety of injuries suggestive of combat (missing clusters of body feathers, bruises) and others suggestive of attempted predation (missing tail feathers, dislocated legs). Skin punctures and abrasions could result from either of those causes or from collisions with sharp objects (e.g., plant thorns/spines). Even relatively fresh wounds seldom show any significant blood, because the skin of hummingbirds isn’t highly vascularized like ours (and if you didn’t spend your childhood in a bubble I’m sure you’re aware that puncture wounds may not bleed externally even in humans).

      What I don’t see on hummingbirds in hand are the sort of broad, deep puncture wound that could have been inflicted by another hummingbird’s bill (they’re not as sharp as you think they are), missing eyes (birds that do stab in combat or self-defense, such as herons and cranes, frequently go for their opponents’ eyes), or bills stained with blood suggesting infliction of penetrating wounds. Over thousands of hours spent watching hummingbirds, I’ve seen a few aggressive individuals pin down others and “stab” (poke) them, in one case repeatedly over more than a minute, but in each case the “victim” flew off a little disheveled but otherwise unimpaired, with no sign of blood on either party. See also “Fawn-breasted Brilliants in combat.”

      The one hummingbird I’ve ever seen with a bloody neck wound similar to your description was dead and being chewed on by a Chinese mantid, an extremely common predator in gardens across North America. A predator doesn’t “change its mind” about eating a kill unless it discovers that it’s unpalatable, but small ones in particular may abandon unconsumed or partially consumed prey out of fear, satiation, or fatigue. Put yourself in the place of a mantid or shrew and I’m sure your vivid imagination will provide you with at least one reasonable alternative to death by hummingbird.

      • Please pardon the sarcasm and thanks for your thorough and detailed reply. I know that wildlife, no matter how charismatic, have a precarious existence, and that I shouldn’t be shocked or angry when I encounter evidence of that.

  16. I live in Oregon and have never whitnesed a fight to injury or even death. Yes the little bird is agresive come feeding time. But have you ever watched a horse in a pasture of horses come feeding time, an animal of considerable size compared to a hummingbird But noon the less agresive at feeding time. I been feeding Hummingbirds for 20 years and neve whitnessed a bloody battle yet. Matter of fact we were blessed with lots of babies at our feeders this year :)

    • Thanks for commenting. Please note that your commercial link has been removed in accordance with this blog’s zero-tolerance policy for spam.

  17. My wife and I just witnessed a fight to the death between two male Anna’s hummingbirds near our feeder( we have had one for about six years). It was a brutal sight. I tried to break it up but then noticed that the losers eyes were already gone. I video taped this beating for about 10 minutes. I was thinking about putting it on youtube but think it might be too strong for kids. It took about 2 hours for the winner to finish him off. He would not leave until that bird was dead. Later on in the battle, the winner would take feeding breaks.

    • It’s hard to say what was wrong with the “loser” without seeing the start of fight, but a healthy hummingbird would have broken away and fled before a stronger competitor could injure it to this degree. Window collision is a very common cause of disability in developed areas, and other cases of stunned birds being attacked by healthy ones have been reported.

  18. I recently observed two hummingbirds on the ground under one of my feeders. I stopped to watch what I presummed to be mating. One bird was standing on top of the other. It took me awhile to realize the weren’t mating but fighting.

    By the time I got to the door, the antagonizer had flown back to his favorite spot, and the poor little male on the ground was near death.

    It was raining, so I picked up the injured bird and took him in to the warm house in a small box. Before long he started coming around, but the lower part of his bill was slanted about 45 degrees off to the left. He kept trying to move his mouth, but the bill wouldn’t align with this top bill. He started trying to fly, so I took him outside where he made a feeble attempt to leave. He crashed on the ground again and sat for 5 minutes or so and then took off to the neighbors yard.

    The other hummer didn’t kill him outright, but injured him so badly I’m sure he couldn’t survive. I was sad, but it’s the way nature works. I wish I had been able to get this guy to a rescue center, but we are in Palm Springs and the only place I know would be the living desert facility and they were closed.

    • I wouldn’t be too sure about that, Dave. Hummingbirds are incredibly tough, though whatever problem prevented the bird from fleeing or fighting back would also be likely to compromise its recovery.


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