Rehabilitate and release injured or accidentally caught individuals: Crocodilians
Overall effectiveness category Awaiting assessment
Number of studies: 1
Background information and definitions
Reptiles that are injured, sick or found in a weak condition are sometimes taken in by wildlife rehabilitators, to be treated and released back into the wild. Animals may be injured or weakened due to direct interactions with human threats, for example entanglement in fishing gear, or due to natural threats such as extremes of weather caused by climate change (for example sea turtles may become ‘cold-shocked’ due to sudden severe cold weather). Often rehabilitation is carried out more for animal welfare reasons than for species conservation. However, for rare species it may be essential to preserve populations and release of such animals may provide opportunities for choosing where to augment populations. The success of such programmes can be difficult to judge without benchmark data for survival of wild-reared reptiles. It is also important to note that some of the studies summarized below have small sample sizes, and that unsuccessful attempts are less likely to have been reported.
Due to the number of studies found, this action has been split by species group, though no studies were found for amphisbaenians. See here for: Sea turtles; Tortoises, terrapins, side-necked & softshell turtles; Snakes & lizards or Tuatara.
For studies evaluating the effect of releasing reptiles that were accidentally caught in fishing gear, see Threat: Biological resource use – Establish handling and release procedures for accidentally captured or entangled (‘bycatch’) reptiles and Release accidentally caught (‘bycatch’) reptiles.
Supporting evidence from individual studies
A study in 1977–1981 in a river with a series of pools in Andhra Pradesh, India (Choudhury & Bustard 1982) found that accidentally captured mugger crocodiles Crocodylus palustris that were raised in captivity before being released survived for at least 1-4 years following release. At least seven of eight released crocodiles survived for at least 1–4 years after release. All crocodiles were re-sighted at the release site, or within 100–3,000 m away. Authors reported that the first breeding took place four years after the first release. In 1977–1980, eight mugger crocodiles (5 females and 3 males) were released following rearing in captivity. Crocodiles were between 1.1–1.9 m in length at the time of release. Prior to the release, grazing of cattle and goats along the river bank, fishing and use of the area for swimming and bathing were banned. After release, crocodiles were monitored by both research staff and by staff who were there to protect the release site.Study and other actions tested