Herpetology Notes, volume 13: 753-767 (2020) (published online on 21 September 2020) Herpetofauna of the Santa Cruz Forest Reserve in the Peruvian Amazon Basin Matthew F. Metcalf1,*, Alexander Marsh1, Emerson Torres Pacaya2, Devon Graham2, and Charles W. Gunnels IV1 Abstract. The Amazon is the largest rainforest on the planet and is known for its biodiversity despite growing deforestation from agricultural development, urbanisation, wildfires, and unregulated mining. It is increasingly important to better understand regionalised biodiversity through fauna inventories because of these anthropogenic pressures. We conducted this study between May 2019 and August 2019 to identify herpetofauna biodiversity at the Santa Cruz Forest Reserve in Loreto, Peru. During the study period, we recorded amphibians and reptiles via visual encounter surveys and opportunistic encounters. We further supplemented these sightings by secondary data compiled from previous observations. In total, we recorded 200 species of herpetofauna at this reserve: 15 families of amphibian comprising 106 species, and 21 families of reptiles comprising 94 species. The visual encounter surveys adequately sampled the diversity of amphibians that would have been expected given this protocol and the timeframe of the study. In contrast, this procedure did not sample reptiles as well in terms of both species richness and diversity; more reptile species would be expected given additional sampling. The combined approach of this study, however, provided a robust inventory of the Santa Cruz Forest Reserve, which can be used to support future on-site studies and management plans throughout the region. Keywords. Amphibians, Reptiles, Amazon, Peru, Inventory, Reserve Introduction cattle ranching (Veiga et al., 2002) are major ecological concerns. These industries require large swaths of The Amazon Basin is one of the most complex and disturbed landscapes, which negatively affects wildlife biodiverse regions on the planet (Kauffmann-Zeh, 1999; populations and, therefore, the existence of species and Myers et al., 2000). The extent of this biodiversity is so whole communities that live in the basin (Barlow et pronounced that new species across different taxonomic al., 2016). For example, oil palm plantations fragment groups are discovered each year within the basin (e.g., habitats, which support less diverse communities of ferns: Cárdenas et al., 2016; insects: Perry et al., 2016; wildlife and contribute to polluted waterways (Vijay et fish: Oberdorff et al., 2019). Much of this biodiversity is al., 2016). To mitigate these effects, conservation areas imperiled, however, because of anthropogenic activities such as national forests and ecological stations must (Barlow et al., 2016). Deforestation and habitat degradation as a result of increased mining and oil drilling be established and maintained throughout the Amazon (Finer et al., 2008; Espejo et al., 2018), agricultural because of the extensive endemism that occurs across practices (Glinskis and Gutiérrez-Vélez, 2019), and different areas of the basin (da Silva et al., 2005; Peres, 2005; Freitas et al., 2017). In order to best conserve this rich biodiversity through the further establishment of conservation priorities, we must first understand community compositions within the different regions that make up the Amazon Basin. Amphibians and reptiles make up a significant 1 Department of Biological Sciences, Florida Gulf Coast proportion of tetrapods in the Amazon and are, University, 10501 FGCU Blvd S., Fort Myers, Florida therefore, of significant conservation interest, although 33965, USA. 2 Project Amazonas, 701 E. Commercial Blvd, #200, Fort their presence can be obscured by their small size and/or Lauderdale, Florida 33334, USA. cryptic behavioural patterns. Data on the biogeography, * Corresponding author. E-mail: [email protected] conservation status, and general life history of many 754 Matthew F. Metcalf et al. Amazonian herpetofauna are severely lacking, despite 2019). In addition, the Peruvian Amazon is expected to the fact that amphibians and reptiles are key indicators have among the world’s most diverse species richness of of environmental disruptions (Stuart et al., 2004). amphibian and reptile communities (Vasconcelos et al., For example, these taxa have highlighted the effect 2012; Roll et al., 2017). This is also a rapidly developing of globally infectious diseases such as chytrid fungus area. For example, the human population in the province (Skerratt et al., 2007; Russell et al., 2019) and the of Loreto has grown by 28.6% from 1993 to 2017 and direct biodiversity loss in frogs (Scheele et al., 2019), the urban core of Iquitos, an otherwise isolated city in as well as the indirect biodiversity collapse in tropical the eastern Peruvian Amazon, has grown by 26.4% from snakes (Zipkin et al., 2020). As industrialisation and 2000 to 2015 (INEI, 2020). To add to a growing list of agricultural activities advance throughout the Amazon, herpetofaunal inventories throughout Loreto (see Table reductions and complete losses of amphibian and 1), this study describes the composition of herpetofauna reptile populations are expected (Nobre et al., 2016). in the Santa Cruz Forest Reserve in Loreto, Peru. These Consequently, biodiversity inventories are crucial valuable insights into amphibian and reptile community to evaluate conservation status of herpetofauna structures will provide baseline data for future studies, as communities (Oliveira et al., 2017; Shaney et al., 2017), well as detail the ecological and geographic importance identify regional endemism and new species (da Silva of the Santa Cruz Forest Reserve. et al., 2005; Treurnicht et al., 2017; de Oliveira et al., 2020), and develop proactive conservation management Materials and Methods strategies that mitigate the most destructive effects of Study site.—The Santa Cruz Forest Reserve deforestation (Groves et al., 2002; Guralnick et al., (-3.5214ºS, -73.1803ºW; 115.82 m a.s.l.) is owned 2018). Herpetofauna surveys in the Amazon Basin are and operated by Project Amazonas, which purchased critical to create community baseline structures to assist the first parcel in 2008 (Fig. 1). Additional plots of future research and identify conservation management primary and secondary forest and agricultural lands priorities (Fonseca et al., 2019). were gradually incorporated to create 232 hectares The Peruvian Amazon is one of the most biologically of contiguous protected area. The reserve is located diverse regions within Amazonia (Rodríguez and approximately 22 km northeast of the city of Iquitos. Knell, 2004; Finer et al., 2008). Peru has among the Bordering the reserve is an agricultural property used for highest number of newly discovered amphibian species cattle ranching and yuca (cassava) and plantain farming. globally (Catenazzi and Bustamante, 2007; Wake and There are also three adjacent community reserves which Vredenburg, 2008; Lehr et al., 2017; Santa-Cruz et al., increase the forest continuity outside of the Santa Cruz Table 1. Herpetofauna observed in selected rapid biological inventories from nearby regions within Loreto, Peru, including observationsTable 1. Herpetofauna from the Santa observed Cruz in Forest selected Reserve. rapid biological inventories from nearby regions within Loreto, Peru, including observations from the Santa Cruz Forest Reserve. LOCATION Ns An Ca Gy Ch Cr Lz Am Sn SOURCE Ampiyacu, Apayacu, Yaguas, 104 62 1 1 3 3 19 - 15 Rodríguez and Knell (2004) Medio Putumayo Sierra del Divisor 109 67 1 – 2 1 17 – 21 Barbosa de Souza and Rivera (2006) Mastés 109 74 – – 2 2 18 – 13 Gordo et al. (2006) Nanay-Mazán-Arabela 93 53 1 – 2 2 23 – 12 Catenazzi and Bustamante (2007) Cuyabeno-Güeppí 107 59 – – 3 3 22 1 19 Yánez-Muñoz and Venegas (2008) Maijuna 108 63 1 2 1 1 22 – 18 von May and Venegas (2010) Yaguas-Cotuhé 128 73 1 1 4 3 21 – 25 von May and Mueses-Cisneros (2011) Ere-Campuya-Algodón 128 68 – – 4 2 22 1 31 Venegas and Gagliardi-Urrautia (2013) Medio Putumayo-Algodón 142 89 1 – 4 3 20 – 25 Chávez and Mueses-Cisneros (2016) Santa Cruz Forest Reserve 200 102 1 3 3 2 34 1 54 This study Abbreviations: Ns – number of species; An – Anuran; Ca – Caudata; Gy – Gymnophiona; Ch – Chelonian; Cr – Crocodylian; Lz – Lizard; Am – Amphisbaenian; Sn – Snake. Herpetofauna of the Santa Cruz Forest Reserve in the Peruvian Amazon Basin 755 Forest Reserve boundaries. Much of the reserve is Sampling.—Sampling of herpetofauna occurred primary forest (~60%) and the rest is secondary forest, between May 2019 and August 2019 using visual which is being actively restored through the planting of encounter surveys (VES) along nine different 250- native primary forest vegetation. meter transects throughout the reserve. We conducted VES similarly to methods used by Doan (2003), which did not include time constraints. Observers walked at a reasonable pace but used as much time as necessary to sufficiently sample each transect. VES transects served to sample amphibians and reptiles found on the ground and within the lower canopy. We then conducted transects during multiple time periods to best capture herpetofauna across varying activity patterns. We aggregated diurnal surveys into four time slots: 06:00 – 08:00 h, 08:00 – 10:00 h, 10:00 – 12:00 h, and 12:00 – 14:00 h. Similarly, we conducted nocturnal surveys across four time slots: 18:00 – 20:00 h, 20:00 – 22:00 h, 22:00 – 24:00 h, and 24:00 – 02:00 h. We conducted transects across habitat types found at the reserve and adjacent pasture lands with three replicate sampling transects for each habitat type (primary forest, secondary forest, and pasture lands), resulting in nine unique transects. Over the entire research period, we sampled each transect once per diurnal and nocturnal time slot so that every replicate transect was sampled across all four diurnal and all four nocturnal time slots. Our data include species collected by opportunistic encounters (OE) during the timeframe of this study in 2019. This sampling type represents any species found during the overall stay at Santa Cruz (May to August 2019) but outside of the organised transects. For example, we captured one Drymarchon corais while hiking an unused trail.