Reintroducing a keystone burrowing rodent to restore an arid North American grassland: challenges and successes

Abstract

Prairie dogs (Cynomys spp.) are important ecosystem engineers in North America's central grasslands, and are a key prey base for numerous predators. Prairie dogs have declined dramatically across their former range, prompting reintroduction efforts to restore their populations and ecosystem functions, but the success of these reintroductions is rarely monitored rigorously. Here, we reintroduced 2,400 Gunnison's prairie dogs (C. gunnisoni) over a period of 6 years to the Sevilleta National Wildlife Refuge, in central New Mexico, U.S.A., a semi‐arid grassland ecosystem at the southern edge of their range. We evaluated the population dynamics of prairie dogs following their reintroduction, and their consequent effects on grassland vertebrates. We found postrelease survival of prairie dogs stabilized at levels typical for the species (ca. 50%) after approximately 1 month, while average annual recruitment was ca. 0.35 juveniles per female, well below what was required for a self‐sustaining, stable population. Extreme drought conditions during much of the study period may have contributed to low recruitment. However, recruitment increased steadily over time, indicating that the reintroduced colony may simply need more time to establish in this arid system. We also found well‐known associates of prairie dog colonies, such as American badgers (Taxidea taxus) and burrowing owls (Athene cunicularia), were significantly more common on the colonies than off. After 7 years, we have yet to meet our goal of establishing a self‐sustaining population of Gunnison's prairie dogs in this semi‐arid grassland. But despite the uncertainty and challenges, our work shows that reestablishing keystone species can promote ecosystem restoration.

The functional roles of mammals in ecosystems

“…Because ecosystem engineers and keystone species play such large roles in ecosystems, their restoration often lies at the core of conservation efforts (Davidson et al 2018). Restoring mammals that play critical ecological roles, whether as top predators like wolves or ecosystem engineers like American beavers, has the benefit of restoring entire suites of associated species and ecosystem functions (Ripple and Beschta 2012;Beschta and Ripple 2016;Bouwes et al 2016).…”

Improving Ecological Restoration to Curb Biotic Invasion—A Practical Guide

“…Most restoration efforts to date have focused on species at the same trophic level and the possible consequences for species at different trophic levels have been largely ignored, although pollinators are increasingly a target of restoration. In other words, when reintroducing particular species of animals and planting plants, practitioners should carefully consider what invasive plants or pests might be accompanying the restored species, using information from lessons learned about the plant–animal interactions from nearby species pools (Davidson et al 2018).…”

Translocations of digging mammals and their potential for ecosystem restoration: a review of goals and monitoring programmes

“…Digging mammals can have both positive and negative impacts within ecosystems (Coggan et al 2016, Hennessy et al 2016). For example, the reintroduction of Gunnison’s prairie dogs Cynomys gunnisoni had positive effects on other vertebrate species in New Mexico, USA (Davidson et al 2018), but an existing, urban population of black‐tailed prairie dogs Cynomys ludovicianus in Colorado, USA, facilitated the growth of exotic plant species (Beals et al 2014).…”