We have tried using PVC pipe and have found that it has built-in limitations, so we are sharing our experiences. The soils in most yards within the Las Vegas Valley have been modified as a result of the construction activities or may be naturally too hard for the tortoise to dig to the proper depth. Widening or lengthening the burrow, which a tortoise would normally do as it grows, is something that you may have to do or anticipate. Keep in mind that a snug fit is important for proper insulation from the extreme heat and cold and also helps to prevent dehydration.
The burrow that we recommend is one that you dig and use plywood for the roof. That leaves the floor and the sides for the tortoise to enlarge, soil type permitting. If you use PVC pipe, the sides, as well as the top, are fixed. The second consideration is that a tortoise in a proper fitting burrow should not be able to turn around until it gets to the end where you or the tortoise has made a turnaround beyond the pipe. The fixed sides of PVC pipe mean that if the diameter of the PVC pipe is properly snug; the tortoise may not be able to turn around. You will have to replace the pipe with on of a larger diameter as the tortoise grows and at some point, before you do, the tortoise may become stuck in the pipe. You will have to remember to check it, frequently.
If the soil is so hard that the tortoise cannot dig a turnaround, you will have to do it. The edges of the turnaround must tightly overlap all edges of the PVC pipe and yet the turnaround area must be wider than the pipe. If you do not dig a turnaround, several unwanted things may happen. We have observed the following as the tortoise tries to scrape at the hard soil. The digging action includes reaching upward. The soil above the end of the pipe– the soil that you added– is relatively loose. As the tortoise tries to dig at the end of the burrow, loose soil from above falls and the tortoise will push it under him, raising the tortoise as it continues to dig. If the tortoise escapes being trapped against the top of the burrow or is buried in loose soil, it will tend to break the surface just beyond the end of the pipe. Covering the area beyond the end of the pipe with soil that will not hold its shape is as bad as soil too firm to dig.
If you dig a channel for a pipe with a diameter larger than the present width of your tortoise and can secure several smaller diameter pipes to nest in the larger ones, this will allow you to have a burrow that fits now and as the tortoise grows by withdrawing the outgrown pipe the next larger diameter will be ready to use.
Another option is to use pipe that is too wide now and fill it almost to the top with rock-free soil. Tamp it down along the center line so the tortoise just fits and does not sink into the soil. As the tortoise grows it will excavate that soil. With the diameter of the pipe so much greater than the width of the tortoise, a snug fit may not be possible. The tortoise may refuse it if it is too spacious. If you choose to install pipe that is much wider than the tortoise you should increase the length by at least half. This may partially compensate for the lack of snugness by reducing the draft which allows too much air/temperature exchange and loss of moisture.
In very hard soil or loose soil that won’t hold its shape, you may choose to build a turnaround out of wood or cinder blocks (this may be larger than your tortoise needs, now). Be sure to set the sides of wood or cinder block on a wood floor. If you set the turnaround on bare soil the tortoise will probably dig under and the turnaround, wood or cinderblocks will settle on the tortoise. There should be enough soil in the turnaround to make it snug for the present size of your tortoise. The tortoise will excavate and remove the excess soil as it grows.
If you think about boarding up the far end of the pipe, not allowing the tortoise to lengthen its burrow, this has at least two consequences. It frustrates the tortoise’s natural tendency to lengthen its burrow and your tortoise may waste a lot of energy scratching continually. Installing such a barrier so it will stay in place is difficult; tortoises are very strong and persistent. Be ready to find your tortoise stuck or partially out the back end. Check for this. If you choose this method, the diameter of the pipe must be wide enough to allow the tortoise to turn around and this brings in the challenges, mentioned above, of making such a burrow fit snugly for the tortoise. A tortoises can back up but first it may try to turn around and become wedged in the pipe.
Sources of pipe greater than 12″ in diameter may not be available locally. Most adults will eventually need 15″ to 18″ diameter if there is no turnaround beyond the end. Most pipe comes in 20′ lengths. This must be cut lengthwise and then across to the desired length. Cutting PVC pipe is very hard on wood-cutting blades.
Hatchlings and small juveniles. Because burrows for hatchlings and small juveniles are easier to dig up and remake as the tortoise grows, there is an alternative type of burrow that you might try. See Tortoise Group Information Sheet # 14, Burrows for Hatchling and Juveniles up to 31/2″ Shell Length.