A camera trap assessment of the terrestrial mammals in Machalilla National Park, West Ecuador
Key words: mammals, regional list, west Ecuador, conservation, human‐modified landscapes, protected area
Evaluating the abundance and distribution of terrestrial mammal communities is vital to promote efficient management plans and targeted conservation actions (Jenkins 2013). Yet, we first need up-to-date, accurate and rigorously recorded data of the species present in an area to provide the basis of further analysis (Antos 2014). This is especially important for medium and large sized mammals inhabiting tropical forests, as they are excellent indicators of ecosystem health, present high levels of diversity, and yet they are highly threatened mainly by human activities such as hunting, natural resource extraction, expansion of the agricultural and cattle frontier, and habitat loss and fragmentation (Carrillo 2000, Schipper 2008, Rodrigues 2009). The western lowlands of Ecuador compromise part of the Tumbes-Chocó-Magdalena hotspot (Myers 2000), which presents the highest population growth rate within the world hostpots (Cincotta 2000). An increase of the population size translates into an increase of the demand of goods, resources and infrastructure, which can potentially represent a major risk for the native flora and fauna of the region.
The most commonly used methods to study the mammals present in an area include line transects (direct and indirect observation), the use of traps and interviews (Plumptre 2000, Silveira 2003, Agostini 2015). Yet, most of the time these methods are hard to replicate, standardize and are likely to present some degree of bias (Ahumada 2013). Camera traps provide an alternative tool for improving data recording of medium and large mammal species (Tobler 2008). Several factors have led to an increase of this method over the last decades, which include the opportunity to maximize encounter rate of mammals, especially the cryptic ones, they are relatively inexpensive, efficient and easy to provide the basis for a standardized methodology (Carbone 2001, Tobler 2008, Rovero 2009, Ahumada 2013).
Although Ecuador is among the most biologically diverse countries of the world (Myers 2000), accurate data on the distribution and abundance of terrestrial mammals inhabiting the Pacific lowlands forests remains incomplete (Parker 1992). An example is the Machalilla National Park, with more than 50,000 ha and only one mammal inventory report published, conducted in 1992 (Parker 1992). Several factors account for the Machalilla NP uniqueness. First, it is one of the largest protected areas of the Ecuadorian coast, creating the opportunity of protecting a large area of highly threatened habitats. Second, it presents high levels of flora and fauna abundance and endemism (citation not found: Linares_Palomino_2009) (citation not found: aguirre2006especies) Espinosa 2012). In 1998, Zambrano and Vargas registered 150 endemic plant species in the area. And more recent reports,…(VIOLETA) The literature reports 81 mammal species registered, 69 of them terrestrial, yet this numbers come from a study conducted XXX more than XXX years ago. The high diversity present in the area and the vast threats the species are facing, make this region an ideal location to apply standardized methods to collect information on the mammal communities and their adaptation to human modified landscapes.
Thus, we identified the need to conduct a study in the Machalilla NP applying a randomized study design with camera traps to provide an up-to-date regional list of medium and large sized mammals and evaluate the conservation status of the species present. In addition to providing baseline data on the species present in this protected area, we considered important to compare our results with a similar study conducted in 1992 (Parker 1992) to evaluate possible changes in species distribution.
MATERIALS AND METHODS
Field work was carried out from September 2014 to January 2015 in the Machalilla National Park (1º 32’ S, 80º 40’ O) and its boundaries (Fig. 1). The Machalilla National Park was created in 1979, and is located in the province of Manabí, south-west Ecuador. The area encompasses more than 70.000 ha, where 56.184 ha are terrestrial and 14.430 ha are marine. CLIMA And mean annual temperature is 24ºC (Fiallo & Jacobson 1995). Mean annual precipitation is 424mm, yet it varies greatly, with an average of 300mm between December and May (rainy season), and 20mm between June and November (dry season) (Cisneros-heredia 2000).
Vegetation types in the Machalilla National Park vary drastically in relation to the altitudinal and moisture ranges, and include coastal dry scrub in the lowlands; tropical dry forest, between approximately 150 and 300 m; transitional forest, in a small strip between approximately 300 and 350 m; and tropical fog forest, from 350 to the upper height of 840 m (Parker 1992, Cerón 1997, INEFAN-GEF 1998). Although the vegetation presents a high degree of endemic species, specially in the tropical dry forest, with a 20% rate of endemic species, there is an important lack of ecological and structural information of these forests and, moreover, there is a strong anthropogenic pressure related to urbanism, agriculture, cattle and timber extraction, that endangers the Machalilla National Park ecosystems and, thus, its fauna (Aguirre 2006, Espinosa 2012, Parker 1992, Cerón 1997).