The amphibians and reptiles of Luzon Island, Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range

Abstract

We provide the first report on the herpetological biodiversity (amphibians and reptiles) of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces), northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province), as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province), combined with all available historical museum records, suggest this region is quite diverse. Our new data indicate that at least 101 species are present (29 amphibians, 30 lizards, 35 snakes, two freshwater turtles, three marine turtles, and two crocodilians) and now represented with well-documented records and/or voucher specimens, confirmed in institutional biodiversity repositories. A high percentage of Philippine endemic species constitute the local fauna (approximately 70%). The results of this and other recent studies signify that the herpetological diversity of the northern Philippines is far more diverse than previously imagined. Thirty-eight percent of our recorded species are associated with unresolved taxonomic issues (suspected new species or species complexes in need of taxonomic partitioning). This suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study.

Amphibians and reptiles from the Mt. Hamiguitan Range of eastern Mindanao Island, Philippines: new distribution records

“…Important habitats we observed that are critical to species survival include riparian vegetation, leaf litter, tree stumps, dead logs, fallen trees, tree foliage, swamps, and creeks, all of which are found in forested areas. Our observations are consistent with those from other studies Brown et al 2001Brown et al , 2012Brown et al , 2013bMcleod et al 2011;Siler et al 2011Siler et al , 2012Gaulke 2011;Devan-Song & Brown 2012;Plaza & Sanguila 2015;Siler et al 2016), emphasizing how these habitats are among the highest priority for research and conservation value.…”

“…Repeated surveys in different seasons or times per year, focusing on variety of habitats, and systematic analysis of natural populations are necessary to determine if the species populations are increasing or declining. If these data are not available, assessment of species conservation status will be of limited value, incomplete, or much worse, providing incorrect information, which can mislead conservation planning (e.g., the case of Platymantis polillensis in the Philippines; Brown et al 2012Brown et al , 2013b.…”

“…Species habitat preference, microhabitats in particular, are important to amphibians and reptiles (Brown et al , 2013b), yet these are often neglected or overlooked in most protected areas in the Philippines, being absent or not even considered in management plans (Supsup 2014;Fauna & Flora International Philippines unpublished data). The species habitat characterizations we provided here are preliminary, but provide a general initial view of the habitats utilized by recorded species.…”

“…Figure 4c Bronchocela cristatella was previously considered to be widely distributed in Southeast Asia and the Philippines (Hallermann 2013;Grismer et al 2015Grismer et al , 2016Zug et al 2017). At present, taxonomic issues plague the understanding of Philippine populations (see Brown et al 2012Brown et al , 2013b. Brown et al (2013b) suggested that the group from Luzon could be recognized as B. marmorata, but Mindanao populations may not necessarily be associated with this name and they are likely not conspecific with B. cristatella (type locality: Sulawesi, Indonesia).…”

“…At present, taxonomic issues plague the understanding of Philippine populations (see Brown et al 2012Brown et al , 2013b. Brown et al (2013b) suggested that the group from Luzon could be recognized as B. marmorata, but Mindanao populations may not necessarily be associated with this name and they are likely not conspecific with B. cristatella (type locality: Sulawesi, Indonesia). We observed this species on degraded secondary growth forest ca.…”