Dja Reserve — Institute of the Environment and Sustainability at UCLA

For the past 20 years, we have been conducting research in the Dja Biosphere Reserve and adjacent areas. The Dja Biosphere Reserve is a UNESCO World Heritage site located in South Central Cameroon. The reserve comprises over 500,000 hectares, making it one of Central Africa’s largest protected areas. Our research began in 1993 with the establishment of the Bouamir research camp and 25-square-kilometer study site located near the center of the reserve. Since that time, research has focused on the role of vertebrate seed dispersers-particularly birds and primates, the impacts of hunting on vertebrate populations and on the genetics of the trees they disperse, conservation genetics, mechanisms of speciation, and disease research, both in the reserve and in adjacent areas. CTR also used the Dja as a base for groundbreaking work on the long distance movement and resource use of hornbills. We work closely with indigenous tribes who live in and around the Dja Biosphere Reserve as part of our research. Community members act as guides, and share their extraordinary wealth of knowledge about the ecology of the forest.

Tracking Hornbill Movements in Cameroon

UCLA’s International Research & Training Center in Cameroon hosts researchers such as Prof. Tom Smith and his team from the Center for Tropical Research. Prof. Smith leads the IRTC and shows here how the research team captures hornbill birds and attaches a satellite tracking device in order to track their movements across the Congo Basin for the first time.

Related Publications

Declines of ebony and ivory are inextricably linked in an African rainforest

Vincent Deblauwe , Matthew Scott Luskin , Serge Désiré Assola, Olivier J. Hardy , Simon Jansen , Céline Loubières , Gaston Guy Mempong, Jean Mathurin Ntsihe, Gilbert Oum Ndjock , Eric Rostand Onguene Kwecheu , Luke L. Powell , Bonaventure Sonké , and Thomas B. Smith

Published Work 2025

Avian influenza surveillance in Central and West Africa, 2010-2014

Fuller, T. L.; Ducatez, M. F.; Njabo, K. Y.; Couancy-Hymann, E.; Chasar, T.; Aplogan, G. L.; Lao, S.; Awoume, F.; Tehou, A.; Langeois, Q.; Krauss, S.; Smith, T. B.

Published Work 2014 | Epidemiology and Infection 143(10), 2205-2212

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Evolution and conservation of Central African biodiversity: priorities for future research and education in the Congo Basin and Gulf of Guinea

Anthony, N. M.; Atteke, C.; Bruford, M. W.; Dallmeier, F.; Freedman, A.; Hardy, O.; Ibrahim, B.; Jeffery, K. J.; Johnson, M.; Lahm, S. A.; Lepengue, N.; Lowenstein, J. H.; Maisels, F.; Mboumba, J.; Mickala, P.; Morgan, K.; Ntie, S.; Smith, T. B.; Sullivan, J. P.; Verheyen, E.; Gonder, M. K.

Published Work 2014 | Biotropica 47(1), 6–17

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Spatial and temporal patterns of frugivorous hornbill movements in Central Africa and their implications for rain forest conservation

Chasar, A.; Harrigan, R. J.; Holbrook, K. M.; Dietsch, T. V.; Fuller, T. L.; Wikelski, M.; Smith, T. B.

Published Work 2014 | Biotropica 46(6), 763–770

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Diet selection is related to breeding status in two frugivorous hornbill species of Central Africa

Lamperti, A. M.; French, A. R.; Dierenfeld, E. S.; Fogiel, M. K.; Whitney, K. D.; Stauffer, D. J.; Stouffer, K. M.; Hardesty, B. D.; Clark, C. J.; Poulsen, J. R.; Wang, B.; Smith, T. B.; Parker, V. T.

Published Work 2014 | Journal of Tropical Ecology 30(4), 273–290

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Seed dispersal and movement patterns in two species of Ceratogymna hornbills in a West African tropical lowland forest

Holbrook, K. M.; Smith, T. B.

Published Work 2014 | Oecologia 125, 249–257

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Predicting bird song from space

Smith, T. B.; Harrigan, R. J.; Kirschel, A. N.; Buermann, W.; Saatchi, S.; Blumstein, D. T.; de Kort, S. R.; Slabbekoorn, H.

Published Work 2013 | Evolutionary Applications 6(6), 865–874

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Feeding habits of culicine mosquitos in the Cameroon lowland forests based on stable isotopes and blood meal analyses

Njabo, K. Y.; Smith, T. B.; Yohannes, E.

Published Work 2013 | Journal of Parasitology and Vector Biology 5, 6–12

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Nonspecific patterns of vector, host and avian malaria parasite associations in a Central African rainforest

Njabo, K. Y.; Cornel, A. J.; Bonneaud, C.; Toffelmier, E.; Sehgal, R. N.; Valkiunas, G.; Russell, A. F.; Smith, T. B.

Published Work 2010 | Molecular Ecology 20(5), 1049–1061

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Human impacts flatten rainforest-savanna gradient and reduce adaptive diversity in a rainforest bird

Freedman, A. H.; Buermann, W.; Mitchard, E. T.; DeFries, R. S.; Smith, T. B.

Published Work 2010 | PLoS ONE 5(9)

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Spatially explicit predictions of blood parasites in a widely distributed African rainforest bird

Sehgal, R. N.; Buermann, W.; Harrigan, R. J.; Bonneaud, C.; Loiseau, C.; Chasar, A.; Sepil, I.; Valkiunas, G.; Iezhova, T.; Saatchi, S.; Smith, T. B.

Published Work 2010 | Procedings of the Royal Society B 278, 1025–1033

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Genomic signals of diversification along ecological gradients in a tropical lizard

Freedman, A. H.; Thomassen, H. A.; Buermann, W.; Smith, T. B.

Published Work 2010 | Molecular Ecology 19(17), 3773–3788

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Breeding and nest site characteristics of the Black-casqued Ceratogymna atrata and White-thighed Ceratogymna cylindricus Hornbill in south-central Cameroon

Stauffer, D.; Smith, T. B.

Published Work 2009 | Ostrich 2004, 75(3), 79–88

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Prevalence and diversity patterns of avian blood parasites in degraded African rainforest habitats

Chasar, A.; Loiseau, C.; Valkiūnas, G.; Iezhova, T.; Smith, T. B.; Sehgal, R. N.

Published Work 2009 | Molecular Ecology 18(19), 4121–4133

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Coquillettidia (Culicidae, Diptera) mosquitoes as new natural vectors of avian malaria in Africa

Njabo, K. Y.; Cornel, A. J.; Sehgal, R. N.; Loiseau, C.; Buermann, W.; Harrigan, R. J.; Pollinger, J.; Valkiūnas, G.; Smith, T. B.

Published Work 2009 | Malaria Journal 8

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Birdsong tuned to the environment: green hylia song varies with elevation, tree cover, and noise

Kirschel, A. N.; Blumstein, D. T.; Cohen, R. E.; Buermann, W.; Smith, T. B.; Slabbekoorn, H.

Published Work 2009 | Behavioral Ecology 29, 1089–1095

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The prevalence of avian Plasmodium is higher in undisturbed tropical forests of Cameroon

Bonneaud, C.; Sepil, I.; Milá, B.; Buermann, W.; Pollinger, J.; Sehgal, R. N.; Valkiūnas, G.; Iezhova, T. A.; Saatchi, S.; Smith, T. B.

Published Work 2009 | Journal of Tropical Ecology 25, 439–447

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Character displacement of song and morphology in African tinkerbirds

Kirschel, A. N.; Blumstein, D. T.; Smith, T. B.

Published Work 2009 | Proceedings of the National Academy of Sciences 106, 8256–8261

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Effects of deforestation on the prevalence and diversity of blood parasites in the two African rainforest birds

Chasar, A.

Thesis 2009

Adaptive diversification and anthropogenic impacts on African rainforest biodiversity

Freedman, A.

Thesis 2009

New malaria parasites of the subgenus Novyella in African rainforest birds, with remarks on their high prevalence, classification and diagnostics

Valkiūnas, G.; Iezhova, T. A.; Loiseau, C.; Chasar, A.; Smith, T. B.; Sehgal, R. N.

Published Work 2008 | Parasitology Research 104, 1061–1077

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Modeling the effects of anthropogenic habitat change on savanna snake invasions into African rainforest

Freedman, A. H.; Buermann, W.; LeBreton, M.; Chirio, L.; Smith, T. B.

Published Work 2008 | Conservation Biology 23(1), 81-92

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New species of haemosporidian parasites (Haemosporidia) from African rainforest birds, with remarks on their classification

Valkiūnas, G.; Iezhova, T. A.; Loiseau, C.; Chasar, A.; Smith, T. B.; Sehgal, R. N.

Published Work 2008 | Parasitology Research 103, 1213–1228

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Impacts of hunting on seed dispersal in a Central African tropical forest

Wang, B. C.

Thesis 2008

The importance of conserving evolutionary processes

Smith, T. B.; Grether, G.

Published Work 2008

Hunting of mammals reduced seed removal and dispersal of the Afrotropical tree, Antrocaryon klaineanum (Anacardiaceae).

Wang, B. C.; Sork, V. L.; Leong, M. T.; Smith, T. B.

Published Work 2007 | Biotropica 39(3), 340–347

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An evaluation of fruit availability theory and measurement in an afrotropical rainforest

Fogiel, M.

Thesis 2007

Molecular evidence for host specificity of parasitic nematode microfilariae in some African rainforest birds

Sehgal, R. N.; Jones, H. I.; Smith, T. B.

Published Work 2005 | Molecular Ecology 14(13), 3977–3988

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Comparative seed shadows of bird-, monkey-, and wind-dispersed trees in a central African tropical rain forest

Clark, C. J.; Poulsen, J. R.; Connor, E. F.; Bolker, B.; Parker, V. T.

Published Work 2005 | Ecology 86(10), 2684–2694

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Evaluating the divergence-with-gene-flow model in natural population: the importance of ecotones in rainforest speciation

Smith, T. B.; Wayne, R. K.; Girman, D.; Bruford, M. W.

Published Work 2005 | University of Chicago Press: Chicago, Chicago, USA, 148–165

Blood parasites of some West African rainforest birds

Sehgal, R. N.; Jones, H. I.; Smith, T. B.

Published Work 2005 | Journal of Veterinary Medical Science 67(3), 295–301

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Leucocytozoon (Apicomplexa: Leucocytozoide) from West African birds, with descriptions of two species

Jones, H. I.; Sehgal, R. N.; Smith, T. B.

Published Work 2005 | Journal of Parasitology 91(2), 397–401

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Importance of body size in determining dominance hierarchies among diverse tropical frugivores

French, A.; Smith, T. B.

Published Work 2005 | Biotropic 37(1), 95–100

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Fruiting trees as dispersal foci in a semi-deciduous tropical forest

Clark, C. J.; Poulsen, J. R.; Connor, E. F.; Parker, V. T.

Published Work 2004 | Oecologia 139(1), 66–75

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Hornbills in a human-disturbed rainforest: seed dispersal, habitat suitability, and conservation

Wang, B. C.

Thesis 2004

Aspects of the seed dispersal ecology of Ceratogymna hornbills in Central Africa

Lamperti, A. M.

Thesis 2004

Community seed rain patterns and a comparison to adult community structure in a West African tropical forest

Hardesty, B. D.; Parker, V. T.

Published Work 2003 | Plant Ecology 164(1), 49–64

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Long-distance movements of frugivorous rainforest hornbills

Holbrook, K. M.; Smith, T. B.; Hardesty, B. D.

Published Work 2002 | Ecography 25(6), 745–749

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Closing the seed dispersal loop

Wang, B. C.; Smith, T. B.

Published Work 2002 | Trends in Ecology and Evolution 17(8), 379–386

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A comparative analysis of PCR-based detection methods for avian malaria

Richard, F. A.; Sehgal, R. N.; Jones, H. I.; Smith, T. B.

Published Work 2002 | Journal of Parasitology 88(4), 819–822

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Aspects of foraging in a diverse tropical frugivore guild: behavioral and nutritional patterns

French, A. R.

Thesis 2002

Differential resource use by primates and hornbills: implications for seed dispersal

Poulsen, J. R.; Clark, C. J.; Conner, E. F.; Smith, T. B.

Published Work 2002 | Ecology 83(1), 228–240

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The role of arboreal seed dispersal groups on the seed rain of a lowland tropical forest

Clark, C. J.; Poulsen, J. R.; Smith, T. B.

Published Work 2001 | Biotropica 33(4), 606–620

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Seed dispersal by a primate community in the Dja Reserve, Cameroon

Poulsen, J. R.; Clark, C. J.; Smith, T. B.

Published Work 2001 | Journal of Tropical Ecology 17(6), 787–808

Host specificity and prevalence of Trypanosoma in the African avifauna: a molecular approach

Sehgal, R. N.; Jones, H. I.; Smith, T. B.

Published Work 2001 | Molecular Ecology 10(9), 2319–2327

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Seasonal variation in the feeding ecology of the grey-cheeked mangabay (Lophecebus albigena) in Cameroon

Poulsen, J. R.; Clark, C. J.; Smith, T. B.

Published Work 2001 | American Journal of Primatology 54(2), 91–105

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Frugivore influence on patterns of seed rain, seed shadows, and forest structure

Clark, C. J.

Thesis 2001 |

Resource use, seed dispersal, and feeding ecology of primates in Cameroon

Poulsen, J. R.

Thesis 2000

A test of alternative models of diversification in tropical rainforest: ecological gradients vs. rainforest refugia

Schneider, C.; Smith, T. B.; Larison, B.; Moritz, C.

Published Work 1999 | roceedings of the National Academy of Sciences 96(24), 13869–13873

Seed dispersal movement patterns of Ceratogymna hornbills in Cameroon

Holbrook, K. M.

Thesis 1999

Seed rain in a West African tropical forest

Hardesty, B. D.

Thesis 1999

Seed dispersal by Ceratogymna hornbills in the Dja Reserve of Cameroon

Whitney, K.; Fogiel, M.; Lamperti, A.; Holbrook, K.; Stauffer, D.; Hardesty, B.D.; Parker, V.; Smith, T. B.

Published Work 1998 | Journal of Tropical Ecology 14(3), 351–371

Habitat use and resource tracking by African Ceratogymna hornbills: implications for seed dispersal and forest conservation

Whitney, K.; Smith, T. B.

Published Work 1998 | American Conservation 1(2), 107–117

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Dja Hornbill Project/Projet Calao, 1994-1998

Whitney, K.; Stauffer, D.; Holbrook, K.; French, A.; Poulsen, J.; Smith, T. B.; Fogiel, M.; Lamperti, A.; Hardesty, B.; Wang, B.; Clark, C.; Parker, V.T.

Progress Report 1998

A role for ecotones in generating rainforest biodiversity

Smith, T. B.; Wayne, R. K.; Girman, D.; Bruford, M. W.

Published Work 1997 | Science 276(5320), 1855–1857

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Adaptive significance of the mega-billed form in the polymorphic finch Black-bellied Seedcracker Pyrenestes ostinus

Smith, T. B.

Published Work 1997 | Ibis 139(2), 382–387

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Ecology of Ceratogymna hornbills: seed dispersal, habitat use, and resource training.

Whitney, K. D.

Thesis 1996

Comparative breeding biology of the two bill morphs of the Black-bellied Seedcracker (Pyrenestes ostrinus)

Smith, T. B.

Published Work 1990 | The Auk 107(1), 153–160

Bill size polymorphism and interspecific niche utilization in an African finch

Smith, T. B.

Published Work 1987 | Nature 329, 717-719

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