Juvenile Feeding Behavior

Miguel Landestoy's porcatus vs. skipper

Anolis porcatus juvenile stalks a skipper butterfly (Hesperidae) in Bani, Dominican Republic. Photograph by Miguel Landestoy.

Over the past 6 weeks or so, I’ve been spending a lot of time caring for  Anolis carolinensis hatchlings as part of my common garden experiment. One of the most striking things that I’ve noticed about these growing lizards is how a hatchling’s hunting behavior changes over time. Description of juvenile hunting behavior and a cool hunting video from a different species after the jump…

For the first few days after hatching, the anoles are very wary and spend nearly all their time at top of the cage huddled in between the cage and the lid. They ignore any food (typically 1/8″ crickets) I place in the cage, seeming not to realize that crickets are food and it’s time to eat.  The lizards will eat but only they are on the cage floor and only if the crickets come to them. The lizards aren’t hunters yet.

The real, lizardy hunting behavior that we all know and love starts around 2 weeks of age. The lizard at this age still directs a wary look at the human feeding it, but it quickly forgets the human once it spots a cricket moving, typically in the cage’s potted plant.  The lizard’s gaze shifts to the cricket, just noting its movement for a while. Then, the lizard begins to stalk, moving carefully through the plant until the cricket is within striking distance. A quick pounce, some chewing, and down the hatch.

I was thinking to myself the other day that I needed to get some video of this behavior. Luckily for you all, given my questionable artistic abilities, I found the following link instead. This YouTube video shows a hatchling Anolis vermiculatus stalking and catching a fly. In it, you can see the lizard become aware of the fly, take its eye off the fly to check out what I presume is the human filming, then maneuver itself into strike position, and finally, around 2:15, make the catch. And, the video is set to classical music no less. Enjoy!

http://www.youtube.com/watch?v=KclqdQ8SO2Q

PS: In light of the Glor lab’s recent posts about keeping a lizard colony, I’ll make one comment about feeding captive lizards. I like dropping feeder crickets into the potted plant. The container keeps the crickets from crawling under the cage carpet, at least for a while, and the lizards seem to be more comfortable hunting in the plant than the cage floor.

About Yoel Stuart

Yoel studies evolutionary ecology of Anolis lizards. He is a graduate student at Harvard University, in the Department of Organismic and Evolutionary Biology.
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6 Responses to Juvenile Feeding Behavior

  1. I have also noticed that my hatchlings do not eat during the first week of life outside the egg. I suspect this may be because the baby anoles still have nourishment from the egg in their digestive track. If you hold the hatchlings up to a light, you can see dark matter in their intestinal area that gradually goes away during their first 7-10 days after hatching.

    I’ve been fortunate to watch my most recent hatchling hunt her first cricket. During her first catch she wiggled her tail back and forth as she aimed–not a good idea!! She learned quickly that wiggling her tail caused the crickets to run away and does not do that anymore.

  2. marthamunoz says:

    I wonder if your hatchlings might have exhibited more hunting behavior if you had offered them Drosophila instead of crickets. Your crickets are small, but Drosophila are even smaller, no? Lots of bugs prey on anoles, and something about crickets (however small) may scream “predator” as much as “prey” to a baby anole. I wonder if a small flying insect like Drosophila, rather than a hopping insect would seem more like prey to them. However, it seems very plausible that anoles, as stated above, simply rely on yolk for nourishment the first few days, and begin hunting a little later.

  3. Yoel Stuart says:

    Pin heads and 1/8 inch crickets are about as small as Drosophila. The flightless Drosophila were climbing out of our cages anyway so our hand was forced. In general, I think lizards can handle larger food sizes than you might expect given their head size.

  4. Yoel Stuart says:

    I hadn’t thought to look for any matter in their guts. Cool.

    Interesting that your lizard changed her tail wagging behavior. Reminds me of Leal’s learning lizards!

    https://anoleannals.wordpress.com/2011/07/13/is-an-anole-smarter-than-a-fifth-grader/

  5. cybokat says:

    Anolis porcatus in the DR? Sure that it’s not chlorocyanus?

  6. Yoel Stuart says:

    Yup. Part of an invasive population. Too young to see the pink dewlap.

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