Evolution of a Lizard Room Part I: Introduction

Anolis carolinensis hatchling and the egg from which it hatched

Breeding anoles to look at inheritance of dewlap color has been a major component of my research. It has also, however, been a major frustration. Every step of the process, from keeping the anoles happy enough to reproduce, to finding eggs, to successfully raising healthy hatchlings to adults has required much tweaking over the years. It has certainly been a work-in-progress and I am happy to say that with both minor and major changes over the years, our lab has transformed into a baby-making factory! This post is the first of a series discussing aspects of anole care, in the hope of both sharing our ideas with people in the anole community, as well as to start a discussion on other techniques people are using to breed/care for anoles.

Audrey Kelly armed with the fertilizer spray pump used to mist anole cages

While we are now focused on breeding Anolis distichus, we first started off breeding field-caught Anolis carolinensis in late 2007. Anoles were kept in mating groups of 1 male and 3 females in large KritterKeepers with Astroturf on the bottom and a pair of dowels to serve as perches. Each cage had a small deli cup filled with moist soil for anoles to lay their eggs. All eggs found were also incubated in soil-filled deli cups. To keep the humidity high in the cage, we sprayed the sides of the cages twice a day with water using a fertilizer spray pump.

With this design, we were not finding many eggs and the cages were still not retaining humidity, despite twice-daily mistings. We experimented with plastic sheets over the tops of cages (see photo below) but, as this may have affected the light the anoles were getting, and was also a pain to move when misting the cages, we have since removed the Astroturf and the plastic sheets, and now cover the bottoms of cages with organic potting mix. As the soil retains some moisture from mistings, the humidity in the cages stays over 40%.

Breeding cages with plastic sheets on top to retain humidity, circa 2008

New hatchlings used to be individually housed in large deli cups with screen-topped lids. As hatchlings are at such a vulnerable stage and are prone to desiccation, we thought that large deli cups would retain humidity better than Kritter Keepers. We, however, experienced a high mortality rate and have therefore started housing hatchlings in Kritter Keepers/large acrylic cages (more detail in a future post!), with up to 6 hatchlings in a cage. We are unsure what exactly was the cause of low hatchling survival in deli cups (perhaps air flow?), but survival has since been much higher.

We have made many more changes to various aspects of our anole breeding program, so stay tuned to future posts!

About Julienne Ng

I study the evolution of color signals. My PhD at the University of Rochester focused on the evolution of dewlap diversity in Anolis distichus. I am currently a postdoc at the University of Colorado Boulder studying the evolution of flower color.

6 thoughts on “Evolution of a Lizard Room Part I: Introduction

  1. I am curious about a couple of things. To find eggs are you sifting through all of the potting mix on the bottom of the cages? That seems more laborious than looking in the deli cups. Also, we tried something similar very briefly at Wash. Univ. and found that the soil would occasionally mold once a few crickets died or where the anoles defecated. Do you run into these problems?

    And one last comment, while breeding A. brevirostris, closely related to A .distichus, I have found that this species wouldn’t lay eggs in our potted plants unless the soil is very moist. Once the soil started to dry out all egg production ceased. While I have never quantified it, A. brevirostris seems to be more selective about the conditions necessary to their lay eggs than many of the other species that I have bred in captivity.

  2. While we’ve changed over to potting mix on the bottom of the cages, we still have containers in the cages for anoles to lay in (we’ve since changed to 32 oz yogurt containers – we’ll have another post on these, as they completely revolutionised our egg production!). We only put a thin layer of soil down the bottom to encourage anoles to lay elsewhere, and having only a thin layer means that the soil tends to dry out between sprays. So the yogurt containers remain consistently moister than the potting soil, the anoles have been happy laying their eggs in them. On occasions, we do find eggs in soil that has managed to stay moist.

    Given that the soil dries out, we don’t have too many problems with mould. However, we do also check for eggs in the containers weekly and when we do that, we usually spot clean cages which probably helps eliminate this.

    Interesting about A. brevirostris. We’ve also tried breeding them but they have never been as productive as A. distichus, and perhaps the soil moisture issue explains why. I wonder if that’s reflective of the xeric habitat that they’re typically found in, whereby brevs would need to be more selective of where they lay their eggs since desiccation risk is so high.

  3. We have substrate all over the bottom of our cages for A. ricordi and Chamaeleolis lizards about 2-4 inches deep. It is kept moist to the point that if you push in with your finger, the substrate holds the shape of that hole when you remove your finger. We, too, used to have a problem with mold. We now use coco-peat mixed into our lizard substrates which raises the acidity of the soil and keeps mold down. Another tool that seems to help the mold is using a fan to create good airflow, which will dry out the top layer of soil so that the mold will not form there.

    I would love to hear some ideas that would work for these larger anole species that would save me time during egg checks. We spray twice per day in this set up and the soil can actually get too moist if you don’t take care to avoid it.

  4. Thom, I found that mold was a problem wherever there were dead crickets and/or lizard poop. I would have to go in regularly to clear it out. I had two temperature rooms and the cold room would retain moisture much better than the hot room. While I don’t recommend you keep your lizards at 20C, it might be worthwhile to see what lowering the temperature a few degrees does. I know that at 32 (which is a tad on the hot side), my moisture problems were similar to yours. Most anoles are happy around 29C (based on thermal preference experiments). That might retard the moisture loss a bit.

Leave a Reply

Your email address will not be published. Required fields are marked *

Optionally add an image (JPEG only)