Here on the Anole Annals we like to talk food. Although anoles are predominantly insectivorous creatures, we have documented some of their stranger eating habits on this blog. For example, through recent research we have learned that they are more frugivorous than previously thought. They also include other vertebrates into their diets, such as frogs. Chamaeleolis anoles, we have learned, have specialized molars to aid in crunching mollusks.
Sadly, however, anoles are often also on the receiving side of predation. Anoles are important prey items for many different animals. Sometimes, even plants get their fill on anoles.
In her recently published undergraduate thesis, Dr. Yudisleidy López Ricardo from the University of La Habana, Cuba discusses the diet of the barn owl (Tyto alba furcata) in several localities in Villa Clara and Ciego de Ávila. Dr. López Ricardo examined nearly 300 owl pellets (regurgitated bits that contain food remains) and found 69 different prey types. As expected, small mammals such as the house mouse and black rat were common prey items. A novel finding of this study, however, is that large species of anoles, namely A. equestris, A. porcatus, and even Chamaeleolis sp. lizards were found in the owl pellets. Smaller anoles, including A. jubar, A. sagrei, and A. lucius were also found in the diets of the barn owl. The authors also found that a different herp, the Cuban tree frog, Osteopilus septentrionalis, was not uncommonly found in owl pellets, but this species is nocturnal.
The finding that anoles are a small, but important, component of this species’ diet is quite interesting in light of the fact that Tyto alba, like most owls, is nocturnal. The main question for me is how they are finding and catching anoles. Owls rely heavily on sensitive hearing to locate moving prey at even great distances. But anoles are predominantly diurnal creatures, and are typically asleep and quite still by nightfall. Owls also have great vision and may be spotting anoles during crepuscular hours. Or are they opportunistically feeding on anoles? Perhaps a different predator scares an anole out of its sleeping site and owls are snatching up fleeing anoles.
Any thoughts from the Anolis community on this interesting finding?
Website: www.marthamunoz.weebly.com
- SICB 2018: Revisiting the Fitch-Hillis Hypothesis in Mexican Anoles - January 8, 2018
- Evolution 2017: Urban Anoles Sprint Faster on Smooth Substrates - June 26, 2017
- SICB 2017: New Insights into Pre- and Postcopulatory Selection in Anoles - January 10, 2017
Tony Gamble
Very interesting! Anoles are easy to spot against the foliage while sleeping at night and owls may be able to pick up on that too.
As a side note, owl pellets are not, “dried out feces that contain food remains” but instead bits of undigested material (e.g. bone and fur) that has been regurgitated.
Martha Munoz
Oops! You’re right – duly noted and updated. Thanks!
Manny Hernandez
I beleive these owls are catching the anoles during the day while roosting in dense wooded areas. The anoles move around beneath the canopy, escaping from the intense heat. I believe that If the owl is given an opportunity to get a mid day snack, it will.
Pat Shipman
Even though anoles aren’t active at night, they do have to be somewhere. The question is how do owls find them if they aren’t moving? And I don’t know the answer. I have examined deposits from a cave on Little Cayman and most of the bony contents were undoubtedly owl pellets. And they included the remains of anolises, though I haven’t yet tried to quantify the percentage that is anolis or whether it is A. sagrei or A. maynardi.
It’s a small point, but owl pellets are not dried out feces. They are the indigestible remains of meals that are regurgitated by the owls: bones, claws, feathers, fur and such. They form neat little packages and can often be found beneath a favorite roosting spot.
Miguel Landestoy
Interesting. Here in Hispaniola we have two owls in the genera (Tyto), one is endemic (T. glaucops), and what I get from field observations is that it is more of a forest dweller than the other (T. alba). Not much data on foraging or feeding behavior is available to determine how they get their prey. A published study by ornithologist James Wiley cites another paper (which I haven’t consulted) where is stated that lizards were not among common prey of T. alba (Taylor 1994). However, there is prey item data for comparison between the two species in Wiley’s paper (see tables #1 and 2). The paper shows that T. glaucops has a broader feeding niche and a higher number of herp prey. It is to be assumed that T. glaucops gets more prey variety inside forests and at its ecotones, whereas T. alba is known to inhabit open areas (mostly highly disturbed), mostly in farms, where rodents are among the commonest vertebrate items.
Alan
Here in the UK at least barn owls are often seen hunting in daylight, especially just before dusk when they have hungry chicks to feed. If the Cuban species behaves in a similar fashion they may be picking up the anoles then.