Enclosure design can improve captive husbandry of Pterinochilus murinus (Theraphosidae) by influencing defensive behaviour

Tarantulas (Theraphosidae Thorell, 1869) are typically large-bodied spiders that are frequently kept in captivity as pets in private collections, exhibits in public collections (e.g. zoos), and study animals in research collections. Nevertheless, much of the information on captive maintenance of tarantulas is based on trial-and-error approaches, such that folklore husbandry rather than evidence-based husbandry is typical. In addition to the spider's welfare, some species also impose safety considerations for keepers due to aggressive defensive behaviours that include biting, particularly many Old World tarantulas. The orange baboon tarantula (Pterinochilus murinus Pocock, 1897) is a very commonly kept African species of harpactirine tarantula which is successfully maintained in diverse enclosure designs including arboreal, terrestrial, and fossorial setups. Here, we investigated experimentally how different captive enclosure designs influence defensive behaviour in P. murinus, and whether it is possible to improve both tarantula welfare and keeper safety via husbandry methods. We show that spiders were quicker to flee when kept in arboreal enclosures, but more quickly resorted to aggressive defensive behaviours (rearing and biting) when kept in terrestrial enclosures. Keeping this species in fossorial enclosure designs resulted in a relatively low propensity to flee, rear, and bite, suggesting that this design might be optimal for captive P. murinus welfare and keeper safety.