The pink land iguana from Galápagos: sources of risk

Conolophus marthae (Gentile and Snell, 2009) is endemic to Galápagos islands and is restricted to a single location (Volcan Wolf, Isabela Island), where it lives in sympatry with a population of C. subcristatus. Based on our data and from reports of the Galápagos National Park since 1986, the species has never been observed outside an area larger than 25 Km2. In recent works (Fulvo, 2010; Gentile and Fulvo, 2011), C. marthae’s effective population size has been estimated as large as 41.21 (30.71-67.97; min/max95%) by using microsatellite data. Mark-recapture data, by applying the Lincoln-Petersen method from two contiguous temporal samples in 2009 and 2010, would indicate 192 adult individuals left (155-260; min/max95%). Although rare and with no evidence of F1 hybrids, hybridization may occur (Gentile et al., 2009; Fulvo, 2010), generating introgression between C. marthae and C. subcristatus in volcano Wolf. Hybridization and introgression have not been fully evaluated, yet. In addition to the Galápagos hawk (Buteo galapagoensis), natural predator in volcano Wolf, black rats and feral cats play as introduced predators. In particular, feral cats prey on land iguanas up to three to four years old and are ineradicable from islands as large as Isabela (Nogales et al., 2004). Feral cats could pose a serious threat to C. marthae population recruitment. Further sources of risk, recommendations, and research needs are discussed.