Steven J. Presley
Post Doctoral Fellow
Center for Environmental Sciences and Engineering
Research Interests
My research focuses on community and population ecology of bats and arthropod ectoparasites of bats. The majority of my current research is divided into two interrelated approaches: 1) using data collected from Brazil and Peru to investigate effects of anthropogenic activities (i.e., small scale subsistence farming in the case of Iquitos, Peru and large scale reduced-impact logging in the case of Tapajós, Brazil) on bat populations and assemblages and 2) using ectoparasite populations and assemblages from bats of Paraguay as model systems to explore potential mechanism that mold patterns of abundance, species richness, and biodiversity on host populations and species. Both areas of research employ traditional (e.g., equilibrium theory of island biogeography, more individuals hypothesis, random placement theory, species-area relationships) and recent (e.g., general unified theory of gradients, neutral theory of biodiversity) ecological theories in an attempt to understand the spatial and temporal scales at which particular mechanisms drive patterns of species richness and diversity. Whereas the research involving ectoparasites is more theoretical and heuristic in nature, research on bats in the Amazon basin attempts to apply those same theories to conservation problems.
Host-parasite systems are excellent models to explore questions about factors that affect community and assemblage structure at both evolutionary and ecological scales. Data derived from host-parasite systems may powerfully address ecological questions because they provide a great number of replicates in conjunction with great variation in host or parasite characteristics, wich can be used to explore predictions of contemporary (e.g., nestedness, Neutral Theory) and traditional (e.g., Island Biogeography, More Individuals Hypothesis, species-area relationships) ecological and evolutionary theories. Traditionally, these systems have been under-utilized; however, the amount of published research using host-parasite data is increasing quickly. In part, because these systems provide a great deal of flexibility, but also because data can be collected in conjuction with other projects and a great amount of data can be collected quickly and inexpensively. I am currently working on manuscripts involving analysis of effects of host abundance and host size on ectoparasite abundance, richness and diversity. In addition, for some host-ectoparasite relationships I am analysing patterns of nestedness and co-occurence in an attempt to understand how interspecific interactions effect changes in assemblage structure at multiple scales (i.e., with focus on the host individual, host population, and host meta-population).
Considering rates of economic development and human population growth, associated timber demands likely will preclude establishment of extensive reserve systems that preserve large tracts of pristine forest. Therefore, development of a logging system capable of providing a renewable timber resource with minmal effects on biodiversity is paramount to any conservation effort in the tropics. Over the last 30 years, reduced-impact logging (RIL) practices (as opposed to conventional selective harvesting, timber liquidation or clear cutting) have become increasingly prevalent in the New World. Felling and skidding techniques used in conventional selective logging practices can kill 27 trees of ≥ 10 cm bdh for every harvested tree. In contrast, RIL minimizes damage to surrounding forest while extracting a reduced number (2-4 trees/ha) and volume (5-19 m3/ha) of commercially valuable trees. The cyclic nature and low-impact of these harvests on the physiognomy of the forest may minimize negative effects on biodiversity and provide a renewable resource of economic value.
In contrast to large-scale logging operations typical of the Brazilian Amazon, deforestation in the Peruvian Amazon, especially in the environs of Iquitos, is driven by small-scale subsistence farmers. Deforestation of small 1-2 hectare areas typically takes several days to weeks, during which the understory is removed and most of the trees are felled. The largest trees often are left where they fall. Burning is followed by 2-6 mos of cultivation that results in a plantation covering about 1 ha, which locally is called “chacra”. Chacras typically are planted with pineapple (Ananas comosus, Bromeliaceae), plantain (Musa spp., Musaceae), or manioc (Manihot esculenta, Euphorbiaceae) until the soil is no longer fertile. The influx of pioneer species into abandoned chacras during the subsequent 5 to 10 yrs results in early successional forests that locally are called “purma”. Purma differs dramatically from mature forest in terms of species composition (e.g., Cecropia spp. often dominate) and physical structure (< 10 m canopy, dense understory). Mature upland forest in the region is characterized by high tree diversity with a 30 m canopy punctuated by 50 m emergent trees. Chacra and purma typically have clearly defined boundaries and almost always occur adjacent to mature forest in the Iquitos region.
In the Neotropics, bats provide critical ecosystem services associated with pollination and seed dispersal. Moreover, because they are the sole or primary agents of pollination and seed dispersal for many species of plants, the Phyllostomidae (i.e., New World fruit-eating bats) may represent a keystone taxon in Neotropical forests. Activities of some phyllostomid species promote secondary succession and regeneration of disturbed areas because they differentially disperse seeds of pioneer species of plants. Seed dispersal by animals is integral to the establishment and persistence of a seed bank that is representative of the local flora. Consequently, understanding the effects of logging regimes on bat populations is critical to designing a forest management program that maintains a high degree of natural ecosystem function in lowland Amazonian rainforests.
Currently, we have several manuscripts in preparation and review that evaluate effects of RIL (Tapajos, Brazil) and small scale subsistence (Iquitos, Peru) farming on bat abundance and diversity in the Neotropics. Because effects of logging may manifest at various scales, analyses evaluate responses at population, feeding guild, and community levels.
Education
Bachelor of Science. 1991. Western Illinois University, Macomb, Il. Dr. Jeanette A. Thomas, Advisor.
Masters of Science. 1994. Western Illinois University, Macomb, Il. Thesis Title: Small Mammals of McDonough County, Illinois. Dr. Jeanette A. Thomas, Advisor.
Doctor of Philosophy in Biology. 2004. Department of Biological Sciences, Texas Tech University, Lubbock, Texas. Dissertation Title: Ectoparasitic assemblages of Paraguayan bats: ecological and evolutionary perspectives. Dr. Michael R. Willig, Advisor. PDF
Publications
López-González, C., S. J. Presley, R. D. Owen, M. R. Willig, and Isabel Gamarra de Fox. 1998. Noteworthy records of bats (Chiroptera) from Paraguay. Mastozoología Neotropical, 5:41-45.
Presley, S. J. 2000. (Review of) Ecología de los Vertebrados de Chile by A. F. Jaksic. Journal of Mammalogy, 81:282-284.
Presley, S. J. 2000. Eira barbara. Mammalian Species Account, 636:1-6.
Willig,M. R., S. J. Presley, R. D. Owen, and C. López-González. 2000. Composition and structure of bat assemblages in Paraguay: a subtropical – temperate interface. Journal of Mammalogy, 81:386-401.
López-González, C., S. J. Presley, R. D. Owen, and M. R. Willig. 2001. The taxonomic status of Myotis (Chiroptera: Vespertilionidae) in Paraguay. Journal of Mammalogy, 82:138-160.
López-González, C., and S. J. Presley. 2001. Taxonomic status of Molossus bondae J. A. Allen (Chiroptera: Molossidae), 1904, with new records for Argentina, Brazil, and Paraguay and description of a new subspecies. Journal of Mammalogy 82:760-774.
Presley, S. J. 2005. Ectoparasitic assemblages of Paraguayan bats: ecological and evolutionary perspectives. Mastozoología Neotropical 12:103-105.
Willig, M. R., S. J. Presley, C. P. Bloch, C. L. Hice, S. P. Yanoviak, M. M. Díaz, L. Arias Chauca, V. Pacheco, and S. C. Weaver. 2007. Phyllostomid bats of lowland Amazonian: effects of habitat alteration on abundance. Biotropica 39:737-746.
Castro-Arellano, I., S. J. Presley, L. N. Saldanha, M. R. Willig, and J. M. Wunderle. 2007. Effects of low-intensity logging on bat biodiversity in terra firme forest of lowland Amazonia. Biological Conservation 138:269-285.
Presley, S. J. 2007. Streblid bat-fly assemblage structure on Noctilio leporinus (Chiroptera: Noctilionidae): nestedness and species co-occurrence. Journal of Tropical Ecology 23:409-417.
Stevens, R. D., C. López-González, and S. J. Presley. 2007. Geographical ecology of Paraguayan bats: spatial integration and metacommunity structure of interacting assemblages. Journal of Animal Ecology 76:1086-1093.
Presley, S. J., M. R. Willig, J. M. Wunderle, and L. N. Saldanha. 2008. Effects of reduced-impact logging and forest physiognomy on bat populations of lowland Amazonian forest. Journal of Applied Ecology 45:14-25.
Presley, S. J., and M. R. Willig. 2008. Intraspecific patterns of ectoparasite abundances on Paraguayan bats: effects of host sex and body size. Journal of Tropical Ecology 24:75-83.
M. R. Willig, S. J. Presley, C. P. Bloch, and H. H. Genoways. 2008. Macroecology of Caribbean bats: effects of area, elevation, latitude, and hurricane-induced disturbance. Evolution, ecology, and conservation of island bats (T. Fleming, and P. Racey, Eds.). University of Chicago Press (in press).
Presley, S. J., and M. R. Willig. 2008. Composition and structure of Caribbean bat (Chiroptera) assemblages: effects of inter-island distance, area, elevation, and hurricane-induced disturbance. Global Ecology and Biogeography 17:(in press).
Presley, S. J., M. R. Willig, I. Castro-Arellano, and S. C. Weaver. 2009. Effects of habitat conversion on activity patterns of phyllostomid bats in lowland Amazonian rainforest. Journal of Mammalogy 90:(in press).
Presley, S. J., C. L. Higgins, C. López-González, and R. D. Stevens. Elements of metacommunity structure of Paraguayan bats: multiple gradients require analysis of multiple axes of variation. Oecologia (in review).
Presley, S. J. Interspecific aggregation of ectoparasites on bats: importance of hosts as habitats supercedes interspecific interactions. Oikos (in review).
Presley, S. J., M. R. Willig, L. N. Saldanha, J. M. Wunderle, and I.Castro-Arellano. Reduced-impact logging has little effect on temporal activity of frugivorous bats (Chiroptera) in lowland Amazonia.. Biotropica (in review).
Presley, S. J., and M. R. Willig. Patterns of bat species distribution in the Caribbean: an analysis of elements of metacommunity structure. (in prep).
Willig, M. R., S. J. Presley, and C. P. Bloch. The context-dependent response of walking sticks to disturbance in the Luquillo Experimental Forest in Puerto Rico. (in prep).
Presentations
Presley, Steven J. 1994. Small Mammals of McDonough County, Illinois. American Society of Mammalogists, Washington, D. C.
López-González, Celia, Steven. J. Presley, Robert D. Owen, and Michael R. Willig. 1997. The bat fauna of Paraguay: an updated assessment with comments on the taxonomic status of Artibeus and Myotis. American Society of Mammalogists. Stillwater, Oklahoma.
Galliher, M. H., Michael R. Willig, Robert D. Owen, Steven. J. Presley, and Celia López-González. 1998. Geographic variation and sexual dimorphism in Artibeus lituratus from Paraguay. Southwestern Association of Naturalists, Albuquerque, New Mexico.
Presley, Steven J., Michael R. Willig, Robert D. Owen, and Celia López-González. 1998. Patterns in the composition of bat assemblages from Paraguay. Southwestern Association of Naturalists, Albuquerque, New Mexico.
Pellegrini, Wendy R., Michael R. Willig, Robert D. Owen, Celia López-González, and Steven. J. Presley. 1998. Sexual dimorphism and geographic variation in Sturnira lilium from Paraguay. Southwestern Association of Naturalists, Albuquerque, New Mexico.
Presley, Steven J., Michael R. Willig, Robert D. Owen, and Celia López-González. 1998. Geographic variation in the composition of bat assemblages from Paraguay: a quantitative assessment. American Society of Mammalogists, Blacksburg, Virginia.
Galliher, M. H., Michael R. Willig, Robert D. Owen, Steven. J. Presley, and Celia López-González. 1998. A morphometric analysis of Artibeus lituratus from Paraguay: geographic variation and sexual dimorphism. American Society of Mammalogists, Blacksburg, Virginia.
Pellegrini, Wendy R., Michael R. Willig, Robert D. Owen, Celia López-González, and Steven. J. Presley. 1998. A morphometric analysis of Sturnira lilium from Paraguay: sexual dimorphism and geographic variation. American Society of Mammalogists, Blacksburg, Virginia.
Owen, Robert D., Michael R. Willig, Steven J. Presley, and Celia López-González. 1998. A multivariate assessment of geographic variation in Paraguay bat species assemblages. Eleventh International Bat Research Congress, Brasilia, Brazil.
Owen, R. D., C. López-Gonález, M. R. Willig, and S. J. Presley. 1999. Bat communities in a transitional landscape-what we know from paraguay.. European Bat Research Symposium, Cracow, Poland. August 23-27.
S. J. Presley, M. R. Willig, C. P. Bloch, C. L. Hice, S. P. Yanoviak, M. M. Díaz, L. Arias Chauca, and V. Pacheco. 2005. Anthropogenic effects of bat biodiversity in the Amazon. American Society of Mammalogists, Springfield, Missouri.
S. J. Presley, S. P. Yanoviak, S. C. Weaver, and M. R. Willig. 2005. Effects of human-induced habitat conversion on Arbovirus Ecology in the Amazon. Ecology of Infection Disease, Washington D.C.
S. J. Presley, M. R. Willig, and J. M. Wunderle. 2006. Population level responses of phyllostomid bats to forest management and physiognomy in lowland Amazonia. American Society of Mammalogists, Springfield, Massachusetts.
Willig, M. R., I. Castro-Arellano, S. J. Presley, L. N. Saldanha, and J.M. Wunderle. 2007. Effects of reduced impact logging on bat biodiversity in terra firme forest of lowland Amazonia. American Society of Mammalogists, Albuquerque, New Mexico.
Castro-Arellano, I., S. J. Presley, T. Rangel, L. N. Saldanha, M. R. Willig, and J.M. Wunderle. 2007. Temporal niche overlap in a diverse Amazonian bat community. American Society of Mammalogists, Albuquerque, New Mexico.
Presley, S. J., M. R. Willig, I. Castro-Arellano, and S. C. Weaver. 2008. Effects of habitat conversion on temporal activity patterns of phyllostomid bats in lowland Amazonia. American Society of Mammalogists, Brookings, South Dakota.
Research Grants
1990. Kibbe Life Science Station of Western Illinois University. $200.00.
1995. Department of Energy via Oak Ridge Associated Universities. $1,639.00.
1995. Department of Energy via Oak Ridge Associated Universities. $1,491.50.
1995. Department of Biological Sciences, Texas Tech University. $750.00.
1995. Department of Energy via Oak Ridge Associated Universities. $1580.80.
1998. The Graduate School, Texas Tech University, Junction Summer Scholarship. $500.00.
1998. The Graduate School, Texas Tech University, Summer Research Award. $2,000.00.
1998. American Society of Mammalogists, Grants-in-Aid of Research. $1,000.00.
1998. Department of Biological Sciences, Texas Tech University, Summer Research Award. $3,000.00.
1999. The Graduate School, Texas Tech University, Summer Research Award. $2,000.00.
1999. Department of Biological Sciences, Texas Tech University, Summer Research Award. $500.00.
1999. The Graduate School, Texas Tech University, Junction Summer Scholarship. $500.00.
Professional Organizations
American Society of Mammalogists. 1993-Present.
Resolutions Committee (2006-Present)
American Society of Naturalists. 1995-1998.
Southwestern Association of Naturalists. 1998-2000.
The Association of Biologists, Texas Tech University, 1995-2000.
Constitution Committee (1995)
Faculty Relations Committee (1998)
Budget Committee (1998)