Alsodes vanzolinii (Donoso-Barros, 1974): a new locality in a disturbed habitat for a Critically Endangered species

We report the presence of Alsodes vanzolinii (Donoso-Barros, 1974) in the Maule Region, Chile extending its known geographic distribution 160 km north of its type locality. The species was recorded in exotic young plantations of Pinus radiata D. Don 1836.


Introduction
Alsodes vanzolinii (Donoso-Barros, 1974) is one of the 18 Alsodes species present in Chile (Frost 2017).At the time of its description, by the mid-1970s, A. vanzolinii was regarded as scarce in the temperate forest of the Nahuelbuta Range, Bio Bío Region (Donoso-Barros 1974).Currently this species is considered Critically Endangered presumably due to massive forest replacement by human settlements and Monterey pine (Pinus radiata D. Don, 1836) plantations (Veloso et al. 2010).
During field sampling at Tregualemu (35°58ʹ S, 072°44ʹ W), Maule Region, conducted on a monthly basis from 2014 to 2016, we recorded a total of 5 individuals of A. vanzolinii (Fig. 2), extending its known geographic range 160 km north of the type locality.

Methods
We recorded 1 juvenile and 1 adult within a 15 year old P. radiata plantation (Fig. 3A) and 3 adults at 2-4 year old pine plantations (Fig. 3B).On average, recorded individuals were located at 237 ± 65 m (mean and standard error) from patches of native forests and 72 ± 32 m from mature plantations of P. radiata.These new records expand the geographic distribution of A. vanzolinii and are the first documented records outside the Nahuelbuta Range, supporting claims of its presence in Tregualemu (Celis-Diez et al. 2011).Individuals were assigned to Alsodes vanzolinii according to diagnostic features, such as rounded snout and head, and head depicting a marked light-yellow triangle which contrast with the face dark brown (Donoso-Barros 1974, Rabanal and Nuñez 2008; identification corroborated by senior herpetologist J.J. Nuñez, Universidad Austral de Chile).Specimens were not collected but photographed for species determination.

Discussion
Records at Tregualemu and those of Rabanal and Alarcón (2010) near Ramadillas confirm that A. vanzolinii can use pine plantations as non-native habitat.Whether they are using it for dispersal or as reproductive ground is yet to be assessed.Preliminary evidence suggests that A. vanzolinii might use pine plantations as feeding ground.Stomach content reveals that A. vanzolinii preys upon a diverse suite of invertebrates including Valdivium sp.(Tenebrionidae), a beetle found in mature and young pine plantations (Mansilla 2017).
Although there is no information about the fitness of A. vanzolinii in young pine plantations, its presence in these perturbed environments will require forest managers to adopt practices that favor survival of this endangered species such as enhancing understory vegetation within young pine plantations.

Figure 2 .
Figure 2. Individuals of Alsodes vanzolinii (not collected) found in Tregualemu, Maule Region, Chile. A. Juvenile individual found in mature pine plantation.B. Adult individual found in young pine plantation.