Travis Stein, CMAR, ILAM

Assistant Manager Husbandry Services

University of Michigan

Ever since I was young, I have been in love with our hoppy little, slime coated friends called frogs. My journey, pining for my goal of becoming a frog myself, has brought me to conservations, zoos, and into academia. Not once have I been allowed to give a frog a banjo, and only one time did someone let me introduce a frog to a pig, which ended in less violence than the movie, but an interaction I would still not recommend. My recommendations depends on the type of frog.

What Maketh a Frog?

Through zoos and conservations, the number of frogs, I’ve been exposed to is about 30 different frogs.  Currently there are 4 different types of frogs at my institution, Xenopus Laevis, Xenopus Tropicalus, Dwarf frogs, and Dart frogs.   These frogs have ranged from fully aquatic, deranged looking styles whose scientific name is actually alien because of how weird they look, to the type of frog that if you accidently get them wet while misting their cage, they look at you like you committed a crime. Each of these different species have different requirements for their enrichment, because as we know enriching the lives of any animal is about simulating their natural environment. Effective enrichment for frogs must take into account the frogs natural environment.  For example, if you give an aquatic frog a dome hut, it will most likely ignore it.

Close Encounters of the Frog Kind

If you have Xenopus Laevis, these little amazing hoppers can adjust to anything, they are like us after the pandemic. Change? No problem. What makes them happy though? Their natural, non-invasive environment which is in stagnant ponds. The ponds full of mosquitos that are all brown and gross looking, and you don’t let your kids swim in. These ponds are relatively devoid of higher plant life and are full of algae. They just stay there all day, scooping up the bugs, and living a relaxed life.

Many Mates in the Murk is Marvelous

Where do our laevis live? In the murk surrounded by their friends as xenopus laevis are very social creatures. It is imperative that these frogs are housed with their fellows, in simulated murky conditions. By simulated murky conditions you should have your cages tinted in some fashion. It is always easiest to see animals in clear, see-through cages in a brightly lit room, but that it is not necessarily what is best for the frogs. They live in the mud, so make sure their tanks are tinted as such. A good greyish brown tint on a tank will reduce stress and increase oocyte production, as it is a  now a simulation of their natural environment.

The most common enrichment I’ve seen in research labs are PVC pipe hiding places. The success of the PVC pipe really depends on tank density and the availability of the pipes. Territorial aggression over PVC pipes can negate the calm environment that you are trying to provide, making the pipes completely null and void. You need ample space for the xenopus to move around the tank, while also enough piping to prevent fighting over a singular piece of enrichment. Anything less than 2 adequately sized pipes per 10 frogs will causing fighting, while if your tanks are too small and they take up too much space it will also cause more aggression.

Artificial plants are not very useful as their natural environment is almost completely devoid of higher plant life. Conversely, natural plants work for xenopus species and are necessary as they use them to hold themselves up in the water. Xenopus Tropicalis, as well as most terrestrial species of frogs all benefit from the use of plants or simulated plants in their environment. For aquatic frogs, the use of fake plants are usually best, as live plants do not offer much more stimulation but require a ton more work for husbandry staff. Terrestrial froggy friends benefit the most from live plants and it is almost necessary, depending on the species, to have them in the terrarium.

These frogs have been with us in the lab for decades, yet we’ve only begun to explore what enriches their lives the best. Different styles of feed, caging, and manipulanda are there to explore. As we continue to look for new and exciting enrichment projects for cute, furry critters, it is my hope that we continue to explore this realm for our slime coated friends as well. We owe a history of environmental and developmental knowledge to these amphibious creatures, and they deserve the same kind of love our fellow mammals receive.