Abstract:
The electric stunner (e-stunner) is commonly used to handle Nile crocodiles (Crocodylus
niloticus) on commercial farms in South Africa, but while it seems to improve handling and
safety for the keepers, no information regarding physiological reactions to e-stunning is currently
available. The aim of this study was therefore to compare various physiological parameters in
farmed Nile crocodiles captured either manually (noosing) or by using an e-stunner. A total of 45
crocodiles were captured at a South African farm by either e-stunning or noosing, and blood samples were taken immediately as well as four hours after capture. Parameters monitored
were serum corticosterone, lactate, glucose, as well as alanine aminotransferase, alkaline
phosphatase, aspartate aminotransferase, and creatinine kinase. Lactate concentrations were
significantly higher in noosed compared to e-stunned animals (P < 0.001). No other blood
parameter differed significantly between the two capture methods. In addition, recorded capture
time confirmed that noosing takes significantly longer compared to e-stunning (P < 0.001),
overall indicating that e-stunning seems the better option for restraint of especially large
numbers of crocodiles in a commercial setup because it is quicker, safer, and did not cause a
significant increase in any of the parameters measured.
