A few years ago I asked an ornithologist friend of mine what urban birds such as starlings and house sparrows ate. His answer was that it was probably a mix of bottle caps, cigarette butts, and McDonald’s French fries. I’m only partially satisfied with that answer, and so try to keep an eye on what urban birds eat wherever I go.
Since moving to Miami four years ago, I’ve observed several cases of birds consuming anoles. After watching a Common Grackle feed an anole to a fledgling a few days ago, I thought I’d compile and share these observations with AA readers.
Non – passerines
American Kestrels (Falco sparverius)
Red-shouldered Hawk (Buteo lineatus)
White Ibis (Eudocimus albus)
Great Egret (Ardea alba)
Cattle Egret (Bubulcus ibis)
Passerines
Loggerhead Shrike (Lanius ludovicianus)
Boat-tailed Grackle (Quiscalus major)
Common Grackle (Quiscalus quiscula)
Many of these birds might be considered expected predators of anoles (esp. Kestrels & Great Egrets), but others are perhaps more notable, given the species of birds involved. The non-passerine predators seem unsurprising. These predators forage conspicuously along open, weedy edges, and highway medians for small vertebrates and invertebrates. For example, I’ve seen a Red-shouldered Hawk pick off a nice male A. sagrei from the landscaping in a Target parking lot. And I’ve seen hundreds of Great Egrets and Cattle Egrets devour brown anoles at a rate that would make the most adept anole catchers swoon. It’s hard to estimate this rate from casual observation, but on a recent visit to Fairchild Botanical Gardens, a particularly bold cattle egret followed me around for about half an hour, during which time it caught and consumed over a dozen Anolis cristatellus and A. sagrei (estimated rate ~ 24 anoles/hour!). There was no outward sign of satiation or fatigue in this particular individual and I’ve heard similar stories from other Fairchild visitors suggesting that egret predation can be a significant source of mortality for urban anoles.
But what I find more interesting are the passerine predators. Among the species I’ve noted here, the shrikes, while common in some areas, don’t seem to be terribly abundant and their importance as anole predators is unclear. However, both species of grackle are terribly abundant in urban and suburban areas of south Florida year-round (parking under a choice roosting tree will convince you). To be clear, I’ve only witnessed two grackle predation events during my tenure in S. Florida, however given their active foraging along side-walks, in backyard gardens, and parking lots (prime habitats for urban anoles), I suspect that the importance of these passerine predators might be easily overlooked. Other passerines such as Blue Jays, crows (American and Fish), and possibly Mockingbirds might also be overlooked predators of anoles, but I just don’t know.
On a final note, to get a photo to accompany this post, I followed the female Boat-tailed Grackle pictured above for about five minutes as she wound her way around, under, and atop Ficus and Bougainvillea hedges in what seemed like an obvious search for anoles. I didn’t see her catch anything, but seemingly annoyed by my shadowing she flew over to a dumpster, disappeared for a moment, and emerged with a French fry.
- Knight Anoles Eat Fruit and Pass Viable Seeds - June 21, 2017
- Winter Activity in North Carolina Green Anoles - February 1, 2015
- Are Bark Anoles (Anolis distichus) Native to Abaco Island, Bahamas? - January 23, 2014
James Stroud
Great report, I really enjoyed reading it. Just to add – I have also seen peacocks taking brown anoles, and I imagine it’s just a factor of relative abundance as to why I haven’t seen them catching anything else. That cattle egret sounded wild.
Sean Giery
I totally overlooked peacocks as a predator, thanks! It also seems likely that feral chickens consume a large number of neonates and eggs.
Skip (James) Lazell
My wife, entomologist Dr. Wenhua Lu, observed Pearly-eyed Thrasher predation on an anole in the BVI. She published. Zap me an eddress and I’ll send you the reference:
hq@theconservationagency.org — Skip
Jonathan Losos
How about telling all of us the reference?
James Stroud
Jonathan, the reference was listed just below:
Lu, W. 2009. Anolis cristatellus (Crested Anole). Avian predation. Herp. Review 40(2): 219-220.
Pearly-eyed Thrasher on Guana Island, BVI. Sent to Lisa already…. Skip
Sandy Echternacht
Thanks for the list and observations! It’s not like the anoles aren’t aware of at least some of these predators. Watch for a forthcoming paper in JHerp by Lisa Cantwell reporting research she carried out at UNC-Asheville as an undergraduate comparing the responses of Anolis sagrei to the calls of red-shouldered hawk and kestrels versus cardinals and a sparrows versus Pearly-eyed Thrashers. Lisa now has two summer seasons of field bird call playback experiments of these responses to add to her undergraduate lab study.
In the Cayman Islands we’ve noted early on that Antillean Grackles in the trees above us seemed to be doing exactly what we were doing: looking for lizards. They would walk along a branch, looking on top and under. They had been repoprted as anole predators but it caught us off guard when we found one eating a Osteopilus septentrionalis. It had pinned it on its back and was eating out the belly where, presumably, there are no poison glands.
Rob Heathcote
The burrowing owls that nest in residential areas in Florida seem to take a lot of sagrei. Especially during the spring/summer when the owls sit next to their burrow entrances during the day and seem to make good use of any exposed lizards. I once saw a mockingbird take a neonate as well!
Philip M. Fortman
Large loud animals or machines do not unnerve Cattle Egrets while feeding; whether among the legs of elephants or behind tractor mowers along highways. They have adapted their feeding technique to new continents and environments.
The latest observation occurred while stopped in traffic here in Fort Lauderdale. A Cattle Egret was walking atop the corrugated guardrails just a few feet outside my passenger side window. Low wooden posts support the guardrails. As the Cattle Egret approached each post it went into stalking mode carefully peering over the far side to catch an unwary anoles. Then the bird sprints to the next post and again goes into stalking mode. Since I frequently see this behavior, I hope to get a chance to photograph the technique.
Skip (James) Lazell
Lu, W. 2009. Anolis cristatellus (Crested Anole). Avian predation. Herp. Review 40(2): 219-220.
Pearly-eyed Thrasher on Guana Island, BVI. Sent to Lisa already…. Skip
James Stroud
Hi, I’d really appreciate an electronic copy of this if you have it to hand! jamesTstroud [at] gmail [dot] com, thanks!
Robert Powell
See Powell & Henderson (2008. Iguana 15(1):8–11) for a list of birds observed or recorded as predators on West Indian reptiles (mainly but not exclusively anoles).
Nathan Turnbough
Thanks for sharing your observations! I’ve observed several bird species consuming brown anoles further north in Florida, at a marina (and surrounding environs) in a rural area near Titusville. I was never fortunate enough to witness the actual predation event, only the apparent aftermath – a bird with a limp anole in its mouth, followed by consumption in half the cases. Here’s the list:
– Boat-tailed grackles, two instances involving adult anoles (at least one a good-sized male). I frequently observed this species to exhibit foraging behavior that appeared to be, as noted by others above, directed towards finding anoles, and they often did so in pairs. This included swooping down to the base of a small tree, then quickly hopping or peering around to the opposite side of the trunk (they appeared to be searching the trunk itself, not the ground); if present, the other grackle in a pair would go around or stand watch over the other side. They also would forage among dead, trimmed cabbage palm petiole bases where brown anoles would take refuge, inspecting the crevices as they moved around the palm trunk. Grackle foraging pressure seemed to be greatest in spring.
– Northern mockingbird, with juvenile or small adult anole. Scared it away before it consumed the anole while trying to get pictures
– European starling, juvenile anole. A group of probably 5-10 (not checking my field notes right now) was foraging in a small lawn next to some shrubs when one of them flew up to a telephone wire holding a juvenile anole, which it consumed
– Northern cardinal, female cardinal observed with juvenile or small adult anole in beak in dense scrubby forest on a small island near the marina. I didn’t get a close or long enough look to completely rule out the possibility that it was a green anole, but browns were common on the island and greens comparatively rare. I didn’t get a close or long enough look to completely rule out the possibility that it was a green anole, but browns were common on the island and greens comparatively rare. Flew further into the forest and I did not observe it consuming the anole.
– Barred owl, bird startled from side of road while road hunting further inland in disturbed forest/pasture habitat. Only had a glimpse of it in the headlights before it flew away, but it had a lizard in its beak, almost certainly an anole (small chance it could have been a gecko, but definitely not one of the native lizards). Could have been a green or brown anole.
Sean Giery
Thanks Nathan,
That’s a great set of observations. It looks like passerines could be a pretty important predators. And thanks to everyone for sharing your comments and references. They definitely enriched my understanding.
James Stroud
Incredible observation notes! Thanks for sharing them!
Was the barred owl foraging during the day?
Nathan Turnbough
Thanks! No, the barred owl was at night, while I was road cruising for herps on a dirt road. Unfortunately, when I spotlighted him with my flashlight out the window he took off, and I didn’t get a good enough look at the lizard to determine the species. It looked like an anole.
James Stroud
Wow, that’s really cool in that case then – one would expect the anole to be asleep, so it must have been detected by search image (difficult I imagine?) over any movement or audio cues. Great spot!
Matt Brady
The other day I was observing a migration event on Grand Isle, LA, where hundreds upon hundreds of migrant birds, exhausted after crossing the Gulf of Mexico, were falling out of the sky into coastal woodlots. While watching one particularly bright adult male Scarlet Tanager, a companion directed my attention to a Yellow-throated Vireo that had caught and (apparently) killed a Green Anole. We watched the bird for about a minute as it wrestled with the anole, attempting to wrestle it into a position where it could eat it. Unfortunately, the vireo dropped the anole before it was able to work its way through the skin. We did watch the vireo hammer on the anole several times, as it pinned it down with its foot. We were astounded to see such a small bird take on prey of that size, but given vireo’s taxonomic position, perhaps it’s not that surprising.
Laurel Robertson
I live in Port Saint Lucie, Florida and have observed groups of White Ibis working together to catch anoles. There are often 20-30 and occasionally as many as 50 birds on my neighborhood lawns. My property is bordered by hedges. One or two Ibis will fly up and land on the top of the hedge while 3-5 rush the base of the plant. The geckos are trapped in between and rush back and forth, the birds snap them up greedily and progress down the length of the hedge.
Margaret
What can I do to attract ibis? I’m not fond of the brown black anole population in my treed courtyards and decks.