The effects of abiotic enrichment and predator training on the behavior, morphology, and survival of a species of conservation concern

Abstract

AbstractConservation practitioners often rely on captive breeding programs to supplement wild populations at risk of extinction. While supplementation has been successful for some taxa, the success of using hatchery fish to supplement wild populations is severely impacted by predation. Elevated predation on hatchery fish may arise because hatchery environments often differ from wild environments and constrain the ability of hatchery fish to be adapted to the environments in which they are released. We assessed the effects of abiotic enrichment on the expression of behavioral and morphological phenotypes across three populations of a species of conservation concern, the Arkansas darter (Etheostoma cragini). We also used a factorial approach to assess whether abiotic enrichment and predator training increases survival during encounters with a novel predator. We found that abiotic enrichment affected ecomorphological attributes associated with fins; generally, measures of the caudal and pectoral fin decreased in the treatment group compared to the control treatment. Behaviorally, darters reared with abiotic enrichment increased feeding and decreased movement compared to the control group. Importantly, we found that in combination with predator training, abiotic enrichment increased the probability of surviving first encounters with a predator. We therefore recommend conservation practitioners incorporate abiotic enrichment and predator training in hatchery programs. Captive breeding programs are used to supplement wild populations at risk of extinction, but hatchery‐reared fish often do not survive after release. Using the threatened Arkansas darter, we show that abiotic enrichment and predator training of hatchery populations impact behavior and morphology and increase the probability of surviving first encounters with a non‐native predator.