Okay, this is not an official "study" but I have been experimenting with three different types of substrates for the past two years. All have their pros and cons and merits as a suitable use as a substrate. Perhaps this is a bit trivial as many of you already know the pros and cons of what I am going to say but for someone who may be new, perhaps this is useful information.
Newspaper: still, in my opinion, the best substrate for just about any herp. I still use it quite a bit at home and for many of our off display animals at the wildlife center I run (harmless and venomous alike). For one or two indigos, this is probably the best choice. Its free, parasite resistent, and does not pose a threat for ingestion.
"natural" substrate: I needed something that looked a bit more natural for my wildlife center for our indigo display and after lots of trial and error and experimentation, we found a substrate that looks great and works pretty well too. We basically combine torpedo sand/play sand/top soil/ESU Jungle Mix/Forest Humus/Dried-heat treated leaves that go on the top layer. The exact ratio is tough to say because we use a "Julia Child" approach (a little this, a little that) but in the end, it looks as natural as you can get. It is easily spot cleaned but because its a little darker, you spend more time going through the substrata looking for poop. If someone wants a super nice, naturalistic looking set up, this is not a bad way to go. This substrate, however, can get real heavy and if you are using plastic style cages, it could prove to be too much. Our exhibit indigo is in a very sturdy cherry-wood cage. My home indigos are kept in either Vision or Neodesha cages.
Aspen: I have never been a big fan of using aspen, however, for maintaining a large collection (in my opinion, anything over four by indigo standards is a pretty big collection!), I have found Aspen to be the best substrate choice. The indigos seem to like to burrow into the substrate. Because its light in color, feces is easily spotted and removed and the area can even be disinfected before putting in some additional bedding. The aspen absorbs odors very, very well (my wife doesn't call me every day at work telling me that one of the indigos just took a dump. Or, I don't come home from work and see the whole house lit up by scented candles...a subtle hint from my wife that an indigo did his doody). If you don't stay on top of spot cleaning, though, the room/cage will have a bit of an ammonia odor so it is important to keep the bedding clean and dry but this is fairly easy, even for a large collection. I haven't had any problem sheds despite the rather dry appearance (although my indigos do have access to a humidity chamber that is a sterilite box filled with 3" of slightly dampened newspaper strips or towels). Although the indigos do ingest a little when they feed, it has never caused any impaction problems and they defecate just fine. Some of my messier feeders get fed in a separate, bare floor cage. As long as the prey is completely dry after soaking/thawing, the bedding doesn't tend to stick too much.
CareFresh is another great product but due to the high costs, I don't use it that much. Cypress, though great at holding humidity and easily obtained, is very difficult to keep clean and poses a real danger for ingesting one of those big splinters which will certainly cause beaucoup problems if not death. Plus, I don't like to encourage the destruction of our cypress swamps that are vanishing at a rapid rate. Sani-Chips is one I would also highly recommend but I don't have a resource nearby for getting it on a regular basis; if I did, that would be my choice....great stuff.
You can't go wrong with any of the above choices that I talked about; a lot depends on what you are trying to accomplish as a hobbyist (exhibit to show off to your buddies, something easy to maintain, something that is cheap to maintain). Anyway, nothing earth shattering here, just thought I would share some of our observations over a 2-year period. Perhaps others have different substrates that they have used with success that they would like to share.
Rob Carmichael, Curator
The Wildlife Discovery Center at Elawa Farm
Lake Forest, IL
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Rob Carmichael, Curator
The Wildlife Discovery Center at Elawa Farm
Lake Forest, IL
