My research program is aimed at understanding the origins and determinants of biological diversity in the islands of the Pacific. Hawaii is the perfect place to base this work. My research has been supported by NSF and other granting agencies and has generated numerous publications, many in top-ranked journals (e.g., Evolution, American Naturalist). I am using non-marine snails (land and freshwater) as a model. The advantages of using snails are that 1) they are diverse in the Pacific but not unmanageably so; 2) they are relatively sedentary and thus easily collected and sampled accurately; 3) much of the inter- and intra-specific variation manifested by them is readily recorded by simple methods; 4) the shell remains intact for a considerable time in the field after the animal has died; and 5) there are immense and well-documented museum collections from throughout the Pacific basin going back over a century, including alcohol preserved specimens from which DNA can be extracted.
I am investigating important questions in Pacific biodiversity and related issues from a number of different directions, as follows.
EVOLUTIONARY AND ECOLOGICAL DETERMINANTS OF NON-MARINE SNAIL DIVERSITY
The study of patterns of species diversification is developing rapidly, especially in an evolutionary context, as a complement to the seminal but over-simplistic "theory of island biogeography". Historical biogoegraphy is now at the forefront of evolutionary biology as modern phylogenetic methodologies are applied to questions of the geographic and evolutionary origins of biological diversity. My research incorporates both ecological and evolutionary approaches. Questions I am addressing are: what ecological factors influence distribution patterns; what determines numbers of species on particular islands and archipelagos; what are the geographic and phylogenetic origins of Pacific island land snails? These issues have become the central core of my research over the last few years, funded in part by NSF and USGS/BRD, and have incorporated modern molecular techniques of DNA analysis to develop phylogenies that are the necessary prerequisites for answering many of these evolutionary and ecological questions.
CONSERVATION AND ALIEN SPECIES
The fascinating diversity that has prompted the above research is, however, disappearing. Thus, conservation of the unique island faunas is of crucial importance. I am involved in three main areas addressing conservation issues, focused not only in Hawaii but covering the entire insular Pacific.
Invasion biology
Invasion biology is one of the fastest-growing and important areas of conservation biology. Much of my recent research has focused on alien species, and especially on the patterns and processes of faunal homogenization in Hawaii and throughout the islands of the Pacific, the specific impacts of certain alien species, and the worldwide pathways via which they are spread.
Apple snails
Dealing with alien species in general, led me to become involved more closely with introduced crop-damaging freshwater snails ("apple snails") in Hawaii and South-East Asia. These highly invasive snails have the potential to cause enormous ecological damage. This research is focused on two areas: 1) understanding the dynamics of the invasions, using the snails as a model to address the underlying causes of invasiveness; and 2) the systematics, phylogenetic relationships, and biogeography of the family (Ampullariidae) to which the snails belong.
Conservation ecology
One of the most fundamental questions in conservation biology is why some native species are more vulnerable to extinction (especially in the face of alien invasions) than others. Ecological characteristics of the species are obviously important and have prompted much speculation. Among the native Hawaiian and Pacific snails, some seem less vulnerable than others to the suite of threats they are faced with. In Hawaii, the Succineidae are one of the groups seemingly least in decline. We have begun to investigate reasons for the succineids' relative immunity to these threats. Questions to be asked include the following. Why are succineids in Hawaii still abundant? In fact only some of them are; others seem very rare or gone; why is that? Is life-history important? How does succineid life-history differ from that of better known but more precarious species (e.g., Achatinellinae)? What are succineid habitat and food preferences? Can they survive in non-native habitat? Probably some of them can-why? What are the food preferences of the alien predatory snail Euglandina rosea, which is one of the major scourges of other native Hawaiian and Pacific land snails? What are its ecological limits? Basic ecological research of this kind is essential for understanding the potential for conserving the native species and for directly addressing management options
SELECTED PUBLICATIONS
Cowie, R.H. & Holland B.S. 2006. Dispersal is fundamental to biogeography and the evolution of biodiversity on oceanic islands. Journal of Biogeography 33: 193-198.
Cowie, R.H. 2005. Alien non-marine molluscs in the islands of the tropical and subtropical Pacific: a review. American Malacological Bulletin 20: 95-103.
Cowie, R.H. 2004. Disappearing snails and alien invasions: the biodiversity/conservation interface in the Pacific. Journal of Conchology Special Publications 3: 23-37.
Cowie, R.H. Cazzaniga, N.J. & Glaubrecht, M. 2004. The South American Mollusca of Johann Baptist Ritter von Spix and their publication by Johann Andreas Wagner. The Nautilus 118: 71-87.
Lydeard, C., Cowie, R.H., Ponder, W.F., Bogan, A.E., Bouchet, P., Clark, S., Cummings, K.S., Frest, T.J., Gargominy, O., Herbert, D.G., Hershler, R., Perez, K., Roth, B., Seddon, M., Strong, E.E. & Thompson, F.G. 2004. The global decline of nonmarine mollusks. BioScience 54: 321-330.
Rundell, R.J., Holland, B.S. & Cowie, R.H. 2004. Molecular phylogeny and biogeography of the endemic Hawaiian Succineidae (Gastropoda: Pulmonata). Molecular Phylogenetics and Evolution 31: 246-255.
Cowie, R.H. & Robinson, A.C. 2003. The decline of native Pacific island faunas: changes in status of the land snails of Samoa through the 20th century. Biological Conservation 110: 55-65.
Cowie, R.H. & Thiengo, S.C. 2003. The apple snails of the Americas (Mollusca: Gastropoda: Ampullariidae: Asolene, Felipponea, Marisa, Pomacea, Pomella): a nomenclatural and type catalog. Malacologia 45: 41-100.
Cowie, R.H. & Robinson, D.G. 2003. Pathways of introduction of nonindigenous land and freshwater snails and slugs. In: Invasive species: vectors and management strategies (eds. Ruiz, G. & Carlton, J.T.), p. 93-122. Island Press, Washington, D.C.
Cowie, R.H. 2002. Apple snails (Ampullariidae) as agricultural pests: their biology, impacts and management. In: Molluscs as Crop Pests (ed. G.M. Barker), p. 145-192. CABI Publishing, Wallingford.
Cowie, R.H. 2001. Invertebrate invasions on Pacific islands and the replacement of unique native faunas: a synthesis of the land and freshwater snails. Biological Invasions 3: 119-136.
Cowie, R.H. 2001. Can snails ever be effective and safe biocontrol agents? International Journal of Pest Management 47: 23-40.
Cowie, R.H. & Cook, R.P. 2001. Extinction or survival: partulid tree snails in American Samoa. Biodiversity and Conservation 10: 143-159.
Staples, G.W. & Cowie, R.H. (eds.) 2001. Hawai‘i’s Invasive species. A guide to invasive plants and animals in the Hawaiian Islands. Mutual Publishing & Bishop Museum Press, Honolulu. xii + 116 p.
Asami, T., Cowie, R.H. & Ohbayashi, K. 1998. Evolution of mirror images by sexually asymmetric mating behavior in hermaphroditic snails. The American Naturalist 152: 225-236.
Cowie, R.H. 1998. Patterns of introduction of non-indigenous non-marine snails and slugs in the Hawaiian Islands. Biodiversity and Conservation 7: 349-368.
Cowie, R.H. 1996. Pacific island land snails: relationships, origins, and determinants of diversity. In: The origin and evolution of Pacific island biotas, New Guinea to eastern Polynesia: patterns and processes (Eds. Keast, A. & Miller, Scott E.), p. 347-372. SPB Academic Publishing, Amsterdam.
Cowie, R.H. 1995. Variation in species diversity and shell shape in Hawaiian land snails: in situ speciation and ecological relationships. Evolution 49: 1191-1202.
Cowie, R.H. 1992. Evolution and extinction of Partulidae, endemic Pacific island land snails. Philosophical Transactions of the Royal Society of London Series B Biological Sciences 335: 167-191.
Robert H. Cowie
Researcher in CCRT, Graduate Faculty in Zoology, Graduate Faculty in EECB
B.A. (Natural Sciences), University of Cambridge,1975; M.A. (Natural Sciences), University of Cambridge, 1979; Ph.D. (Zoology), 1982, University of Liverpool