Amphibian and Reptile Project Proposal Yachana Reserve, Ecuador March 2009 1. Introduction One of the key drivers of worldwide species loss is habitat change; defined as habitat deforestation, fragmentation and deterioration (Urbina-Cardona, 2008). The rapid rate of forest conversion in the neotropics has been offset by large-scale expansion of secondary forest, plantation and pastureland (Wright SJ, 2005; Gardner et al. 2007b). Despite the increasingly dominant role of these degraded habitats in the tropical landscape, there is little consensus within the scientific community about the extent of its conservation value (Gardner et al. 2007c, Lo-Man-Hung1, et al. 2008). Wright & Muller-Landau (2006) predict that the future loss of primary forest will be offset by regenerating secondary forest and consequently suggest that the predicted loss of species due to habitat change may be premature. However, there is currently a lack of empirical evidence to support the theory that regenerating forests can fully support native forest species (Gardner 2007c). Two recent multiple taxa assessments, conducted on the cubraca cacao plantations of Bahia, Brazil (Pardini et al. IN PRESS) and eucalyptus plantations of the Jari forestry project, Brasil (Barlow et al. 2007), found that found that responses to structural habitat change were taxon specific. Barlow et al. (2007) found that four of the fifteen taxa analysed (trees and lianas, birds, fruit feeding butterflies, and leaf litter amphibians) were found to decrease in species richness with increasing habitat disturbance. However, five taxa (Large mammals, epigiec arachnids, lizards, dung beetles and bats) exhibit idiosyncratic responses to habitat change (Barlow et al. 2007). Both studies concluded that responses to structural habitat change will be species specific, not simply taxon specific. Analysis of a generalised taxon response is likely to hide a higher level of species specific disturbance responses which are important when designing conservation strategies (Barlow et al 2007; Pardini et al. IN PRESS). These studies highlight the importance of performing multiple taxa assessments that are species specific relating to the conservation value of secondary and plantation forests.
**We would like to conduct multiple taxa surveys within the Yachana reserve, however, I must check with my colleagues before this is confirmed. Consequently, I will now focus solely on amphibians and reptiles**
2. Problem Statement The neotropics are estimated to contain nearly 50% of the worlds amphibians (IUCN, 2007) and 32% of the worlds reptiles (Young et al. 2004), this equates to over 3000 species of each taxon. Within the continental neotropics, the 17 countries in middle and South America, there are 1685 species of amphibian and 296 species of reptiles considered endangered. Amphibians and reptiles are considered to be the most threatened groups of terrestrial vertebrates (J. Gardner 2007b). There have been many factors implicated in threatening populations of amphibians and reptiles, including habitat loss and change, the virulent Batrachochytrium dendrobatidis
pathogen, climate change (Whitfield et al. 2007), ultraviolet-B radiation (Broomhall et al. 2000), and agrochemical contaminants (Bridges et al. 2000). These threats have been classed into two types by Gardner et al. (2007); Current State of Amphibian and Reptile research Amphibians and reptiles are important primary, mid-level and top consumers in Neotropical ecosystems; therefore, it is important to understand the responses of these organisms to structural habitat change (Bell et al. 2006). Despite its apparent severity, the amount of research time given to studying the impacts of habitat change on amphibian and reptile populations is relatively low. This is especially true in the Neotropics which, despite an estimated 89% of threatened species being affected by habitat loss, has only been the subject of 10% of the world’s herpetological studies (Gardner et al 2007a). There is a general consensus amongst herpetologists that the effect of structural habitat change on determining amphibian and reptiles and distributions is limited (Pearman, 1997; Krishnamurthy, 2003; Urbina-Cardona, 2006; Gardner et al, 2007b). A recent global scale review of the state of amphibian and reptile research regarding structural habitat change highlighted several serious deficiencies: i) There is currently a strong study bias away from the Neotropics towards North America and Australia. ii) Published studies report contradictory responses of amphibian and reptile populations to habitat change. iii) There are several common limitations in study methodology and analysis (Gardner et al. 2007a). To address the Neotropical information deficit on herpetofaunal responses to we aim to compare abandoned cacao plantation with primary forest habitats on the Yachana Forestry reserve. Particular efforts will be made to address the current common limitations in herpetofaunal study methodology and analysis by Gardner et al. (2007).
Herpetofauna responses to habitat change Leaflitter herpetofauna lend themselves well to biological conservation studies as they are abundant in Neotropical forests, they are easy to sample and they are regarded as good indicators of habitat change (Faria et al. 2007). The structural habitat changes associated with secondary and plantation forests will cause microhabitat changes through both environmental factors (i.e. incident light, temperature, and relative humidity), and interspecific interactions (i.e., predation, parasitism and competition). These factors combined will influence the richness, distribution and abundance of leaflitter herpetofauna (Urbina-Cardona, 2006). The responses of individual species to these environmental and interspecific factors will undoubtedly vary. To date, several species specific responses have be documented: loss of their reproductive sites, loss of genetic diversity, changes in home ranges, population isolation due to the incapacity to cross anthropogenic matrix habitats, changes in individual growth rates and activity patterns, and changes in microhabitat use (Gibbons et al. 2000; Gardner et al. 2007a; Urbina-Cardona, 2008). Two recent studies report that the variety of microhabitats provided by secondary forest and shaded cocao plantations are sufficient to maintain up to 80% of primary forest leaflitter herpetofauna diversity (Faria et al. 2007; Dixo and Martins, 2008). However, the degree to
which these taxa and the species they contain are affected by habitat change is still relatively unknown (Urbina-Cardona, 2006; Gardner et al. 2007a). Further research into understanding the relationships between leaflitter herpetofauna and their micro habitats is vital to increase understanding of the effects of structural habitat change.
3. Objectives and significance of the research The principal goal of this project will be to use survey data to assess the ability of secondary forest (abandoned cacao plantation) to preserve leaflitter herpetofaunal richness, distribution and abundance in comparison to primary forest habitat. This data will contribute to understanding the effects of structural habitat change within the Neotropics. Further more, by mapping the habitat parameters (canopy cover, leaf litter depth, stem density, etc.) we hope to identify the responses of different herpetofaunal groups/species to structural habitat change. This information could have important consequences for the design of conservational strategies targeting specific groups/species within the Amazon region.
4. Study Site All research will be performed directly on, or in the area immediately surrounding, the Yachana Reserve (see appended map). The reserve is situated within the Napo province in the Amazonian region of Ecuador (0째5' 0"S/077째 13' 60"W; 300-350m altitude). The Yachana Reserve is a legallydesignated Bosque Protector (Protected Forest), consisting of approximately 2000 hectares of predominantly primary lowland rainforest, as well as abandoned plantations, grassland, riparian forest, regenerating forest and a road. The reserve is owned and managed by the Foundation for Integrated Education and Development (Yachana Foundation). The reserve is surrounded by large areas of pasture land, small active cacao farms and un-mapped disturbed primary forest. The road within the Yachana reserve is a large stone and gravel based road which disects the primary forest to the north and the abandoned cacao plantations to the south. Despite walking the road on a frequent basis, field staff have never come across any frogs (dead or alive) on the road itself. A growing body of research suggests that roads can have a negative impact on amphibian diversity (Cushman et al. 2006). They can decrease dispersal, reduce genetic diversity and increase mortality. It is highly likely that the amphibian populations south of the road will be have reduced access the breeding pools within the primary region. Consequently the road is likely to affect the richness, distribution and abundance of herpetofaunal assemblages in both primary and abandoned plantation habitats. These affects must be considered when interpreting any data obtained.
4. Methods Data will be collected over four seven weeks blocks from the 14th of April 2009 until the 14th March 2010. Collecting throughout the year will allow us to determine if there is any seasonal variation in herptofaunal assemblages. The herpetofauna in the Yachana Reserve exhibit different breeding and non-breeding habitats and varying vagility; therefore, no one method will be sufficient to study their populations.
Consequently, we will employ a combination of pit-fall trapping and visual encounter surveys. Using a combination of methods will allow us to describe a wider assemblage of species than the use of a single method. We will establish four 150m transects in both the primary and abandoned cacao plantations. Care will be taken to space the transects sufficiently to avoid psuedoreplication. The transects will be marked with coloured transect tape to avoid unnecessary habitat modification. Where possible, the transects will be located at least 10m from streams to avoid biases resulting from increases in species richness and abundance, which could result in confusion about the true effect of structural habitat change on amphibian and reptile diversity. Nocturnal and Diurnal Visual Encounter Surveys Visual encounter surveys have been shown to be one of the most effective methods for sampling tropical herpetofaunas (Bell et al, 2006). They have been repeatedly shown to yield greater numbers of individuals per effort than other sampling methods in recent publications (Ernst and Rodel, 2004; Donnelly et al 2005) and our own preliminary investigations. Each of the four transects in primary and secondary forest will be split into 75m sections and searched at least four times throughout the course of the sampling year. Each transect will be search by four observers (strip width = 4m, expected duration = 1h 30m). Pitfall trapping Three pitfall arrays will also be established alongside the transects in both primary and secondary forest. Each array will consist of four 35L with a 8m long by 50cm high plastic drift fence connecting them in a Y-shaped design composed of one central bucket and one bucket at the end of each arm. The three pitfalls arrays will be evenly spaced by 50m along each transect. The pitfalls will be checked at least once a day. Due to the hilly topography of the Yachana reserve, it is unlikely that the pitfall arrays will be able to be placed directly on the transect lines. Consequently, they will be located at the first suitable location directly perpendicular of 25m, 75, and 125m of each transect (see fig. 1). Particular care will be taken to ensure that sampling effort is equal for both primary and secondary habitats. This will ensure maximum comparability in the resultant data sets. Any amphibians or reptiles encountered through either method will be identified in the field using available literature, toe clipped to identify recaptures and released. Any individual which cannot be identified will be taken back to Yachana Research station for further analysis. A small proportion of the capture individuals, including those that cannot be identified, will be anaesthetised with Lidocaine and fixed with 10% formalin. All preseserved specimins will be stored at Pontificia Universidad Catolica del Ecuador (PUCE). These specimins will also be swabbed to test for the presence or absence of chytridiomycosis and skin, tissue and liver samples will be taken for genetic testing by PUCE. Surveying primary rainforest habitat is a privileged opportunity; however there is the potential to negatively affect the ecosystem by passing infections between sites and species. Good practices will be strictly adhered to so as to ensure transmissions are not possible. This will be achieved by systematic cleaning of tools, equipment, and sterile bags will be changed when handling different individuals. Under no circumstances will amphibians or reptiles come in contact with exposed human skin tissue.
Figure 1. Transect Layout
Figure 1. shows the planned transect layout. The distances α1,α2 and a3 will be determined by the first perpendicular location suitable for a pitfall array.
Habitat Feature mapping Each 150m transect will be divided into three 50m segments. Each segment will be subjected to vegetation mapping following the guidelines outlined by Ecuadorian Natural Science Museum (MECN) in Quito. At 15m and 50m the following parameters will be estimated; upper canopy cover, height of upper canopy, height of emergent’s, middle canopy coverage, middle canopy height, shrub density, herb density, vine density, palm density, epiphyte density and fern
density. In addition to this protocol, we will take ten leaf litter depth measurements, as standing leaf little depth has been found to be positively associated with density of leaf litter amphibians and reptiles (Whitfield et al. 2005; Urbina-Cardona 2006). Diameter at breast height (dbh) and stem density will also be measured at each site, with the assumption that the number of plants with small dbh is greater in degraded, secondary forests, whereas primary forests show increasing numbers of plants of larger dbh (Pearman, 1997; Rodel et al. 2004).
5. Research staff: Andrew Whitworth completed his MSc in Conservation Biology at Manchester Metropolitan University and currently works as a field officer for GVI. After visiting Tanzania in 2008 he developed a particular interest in the current amphibian crisis and a need for amphibian conservation and research. He now hopes to extend his knowledge towards Latin American amphibian assemblages based at the Yachana reserve. Christopher Beirne graduated in Biological Sciences from the University of Edinburgh in the summer of 2008. Having conducted research on selective logging practises in Bolivia and chameleon population dynamics in Madagascar, he is keen to apply his knowledge to amphibian conservation in the Yachana Reserve.
6. References J. Barlow, T. A. Gardner, I. S. Araujo, T. C. Avila-Pires, A. B. Bonaldo, J. E. Costa, M. C. Esposito, L. V. Ferreira, J. Hawes, M. I. M. Hernandez, M. S. Hoogmoed, R. N. Leite, N. F. Lo-Man-Hung, J. R. Malcolm, M. B. Martins, L. A. M. Mestre, R. Miranda-Santos, A. L. Nunes-Gutjahr, W. L. Overal, L. Parry, S. L. Peters, M. A. Ribeiro-Junior, M. N. F. da Silva, C. da Silva Motta, and C. A. Peres (2007) Quantifying the biodiversity value of tropical primary, secondary, and plantation forests PNAS vol. 104 no. 47 18555–18560 Beebee, T.J.C., Griffiths, R.A., (2005). The amphibian decline crisis: A watershed for conservation biology? Biological Conservation 125, 271–285. K. E. Bell and M. A. Donnelly (2006) Influence of Forest Fragmentation on Community Structure of Frogs and Lizards in Northeastern Costa Rica Conservation Biology Volume 20, No. 6, 1750–1760 Bridges, C.M., Semlitsch, R.D., (2000). Variation in pesticide tolerance of tadpoles among and within species of Ranidae and patterns of amphibian decline. Conservation Biology 14, 1490–1499. Broomhall, S.D., Osborne, W.S., Cunningham, R.B. (2000). Comparative effects of ambient ultraviolet-B radiation on two sympatric species of Australian frogs. Conservation Biology 14, 420–427. Samuel A. Cushman (2006) Effects of habitat loss and fragmentation on amphibians: A review and prospectus Biological Conservation 128; 231 –240 Donnelly, M. A., M. H. Chen, and G. C.Watkins. (2005) Sampling amphibians and reptiles in the Iwokrama Forest ecosystem. Proceedings of the Academy of Natural Sciences of Philadelphia 154:55–69. Toby A. Gardner*, Jos Barlow, Carlos A. Peres (2007a) Paradox, presumption and pitfalls in conservation biology: The importance of habitat change for amphibians and reptiles Biological Conservation 138; 166–179
T. A. Gardner, M.A.Ribeiro-Junior, J. Barlow, T. S. Avila-Pires, M.S. Hoogmeod and C. A. Peres (2007b) The Value of Primary, Secondary, and Plantation Forests for a Neotropical Herpetofauna Conservation Biology Vol 21, 3; 775–787 T. A. Gardner, J. Barlow, L. W. Parry, and C. A. Peres (2007c) Predicting the Uncertain Future of Tropical Forest Species in a Data Vacuum BIOTROPICA 39(1): 25–30 2007 Gibbons, J. W., Scott, D. E., Ryan, T. J., Buhlmann, K. A., Tuberville, T. D., Metts, B. S., Greene, J. L., Mills, T., Leiden, Y., Poppy, S. and C. T. Winne. 2000. The global decline of reptiles, deja-vu amphibians. Bioscience 50: 653–667. S.V. Krishnamurthy (2003) Amphibian assemblages in undisturbed and disturbed areas of Kudremukh National Park, central Western Ghats, India Environmental Conservation 30 (3): 274–282 P. B. Pearman (1997) Correlates of Amphibian Diversity in an Altered Landscape of Amazonian Ecuador Conservation Biology, Volume 11, No. 5 Pages 1211–1225 R. Pardini, D. Faria, G. M. Accacio, R. R. Laps, E. Mariano-Neto, M. L.B. Paciencia, M. Dixo, Julio Baumgarten (IN PRESS) The challenge of maintaining Atlantic forest biodiversity: A multi-taxa conservation assessment of specialist and generalist species in an agroforestry mosaic in southern Bahia Biological Conservation xxx (2009) xxx–xxx M. Rödel & R. Ernst (2004) MEASURING AND MONITORING AMPHIBIAN DIVERSITY IN TROPICAL FORESTS. I. AN EVALUATION OF METHODS WITH RECOMMENDATIONS FOR STANDARDIZATION Ecotropica 10: 1–14, Sala, O.E., Chapin, F.S.I., Armesto, J.J., Berlow, E., Bloomfield, J., Dirzo, R., Huber-Sanwald, E., Huenneke, L.F., Jackson, R.B., Kinzig, A., Leemans, R., Lodge, D.M., Mooney, H.A., Oesterheld, M., Poff, N.L., Sykes, M.T., Walker, B.H., Walker, M., Wall, D.H., (2000). Global biodiversity scenarios for the year 2100. Science 287, 1770–1774.
Stuart, S.N., Chanson, J.S., Cox, N.A., Young, B.E., Rodrigues, A.S.L., Fischman, D.L. and Waller, R.W. (2004). Status and trends of amphibians declines and extinctions worldwide. Science 306: 1783-1786. J. N. Urbina-Cardona, M. Olivares-Pe´rez, V. H. Reynoso (2006) Herpetofauna diversity and microenvironment correlates across a pasture–edge–interior ecotone in tropical rainforest fragments in the Los Tuxtlas Biosphere Reserve of Veracruz, Mexico Biological Conservation 132; 61–75 J. N. Urbina-Cardona (2008) Conservation of Neotropical Herpetofauna: Research Trends and Challenges Tropical Conservation Science Vol.1(4):359-375 Wright SJ (2005) Tropical forests in a changing environment Trends Ecol Evol 20:553–560. Whitfield SM, Pierce MSF (2005) Tree buttress microhabitat use by a neotropical leaf-litter herpetofauna. Journal of Herpetology 39:192-198. Whitfield SM, Bell KE, Philippi T, Sasa M, Bolanos F, Chaves G, Savage JM, DonnellyMA (2007) Amphibian and reptile declines over 35 years at La Selva, Costa Rica Proc Natl Acad Sci 104:8352–8356. Young, B.E., Stuart, S.N., Chanson, J.S., Cox, N.A., Boucher, T.M., 2004. Disappearing Jewels: The Status of New World Amphibians. Natureserve, Arlington, VA.
Yachana Reserve, Napo
Columbia
Laguna
Stream 1
Caimencocha Laguna
Frontier
Green Inferno
Stream 1 Bloop PC17 Bloop Swamp
Inca Stream 1
Cascada
Road
Cascada Stream
Stream 1
Ficus
Agua Santa
Ridge and Road
N
- Ridge trail
Access Routes
Ridge
Rio Napo
GVI Base Camp