ANGGRAINI, K., KINNAIRD, M. & O’BRIEN, T. 2000. The effects of fruit availability and habitat disturbance on an assemblage of Sumatran hornbills. Bird Conservation International 10:189–202.
AOAC 1995. Official methods of analysis of AOAC International. (Sixteenth edition). AOAC International, Gaithersburg. 1200 pp.
BARCLAY, R. 1995. Does energy or calcium availability constrain reproduction by bats? Pp. 245–258 in Racey, P. A. & Swift, S. M. (eds.). Ecology, evolution and behaviour of bats. The Zoological Society of London. Clarendon Press, London.
DATTA, A. & RAWAT, G. S. 2004. Nest-site selection and nesting success of three hornbill species in Arunachal Pradesh, north-east India: Great Hornbill Buceros bicornis, Wreathed Hornbill Aceros undulatus and Oriental Pied Hornbill Anthracoceros albirostris. Bird Conservation International 14.S1:S39–S52.
DHONDT, A. A. & HOCHACHKA, W. M. 2001. Variations in calcium use by birds during the breeding season. The Condor 103:592–598.
DIERENFELD, E. S. 1996. Nutritional wisdom: adding the science to the art. Zoo Biology 15:447–448.
DUNN, E. H. 1980. On the variability in energy allocation of nestling birds. The Auk (1980):19–27.
FOEKEN, S. G., DE VRIES, M., HUDSON, E., SHEPPARD, C. D. & DIERENFELD, E. S. 2008. Determining nitrogen requirements of Aceros and Buceros hornbills. Zoo Biology 27:282–293.
FOGIEL, M. F. 2007. An evaluation of fruit availability theory and measurement in an afrotropical rainforest. M.S. Thesis, San Francisco State University.
GARCÍA-NAVAS, V. & SANZ, J. J. 2011. The importance of a main dish: nestling diet and foraging behaviour in Mediterranean blue tits in relation to prey phenology. Oecologia 165:639–649.
GAUTIER-HION, A. & MICHALOUD, G. 1989. Are figs always keystone resources for tropical frugivorous vertebrates? A test in Gabon. Ecology 70:1826–1833.
GOERING, H. K. & VAN SOEST, P. J. 1970. Forage fiber analysis. Agricultural handbook #379. A.R.S., USDA Washington, DC. 24 pp.
GRAVELAND, J. & DRENT, R. H. 1997. Calcium availability limits breeding success of passerines on poor soils. Journal of Animal Ecology 66:279–288.
GRAVELAND, J. & VANDERWAL, R. 1996. Decline in snail abundance due to soil acidification causes eggshell defects in forest passerines. Oecologia 105:351–360.
HARDESTY, B. D. 1999. Seed rain and dispersal patterns in a lowland tropical rain forest. MA Thesis, San Francisco State University.
HARDESTY, B. D. & PARKER, V. T. 2003. Community seed rain patterns and a comparison to adult community structure in a West African tropical forest. Plant Ecology 164:49–64.
HERRERA, C. M. 1982. Seasonal variation in the quality of fruits and diffuse coevolution between plants and avian dispersers. Ecology 63:773–785.
HOBSON, K. A., SHARP, C. M., JEFFERIES, R. L., ROCKWELL, R. F. & ABRAHAM, K. F. 2011. Nutrient allocation strategies to eggs by Lesser Snow Geese (Chen caerulescens) at a sub-Arctic colony. The Auk 128:156–165.
HOLBROOK, K. M. & SMITH, T. B. 2000. Seed dispersal and movement patterns in two species of Ceratogymna hornbills in West African tropical lowland forest. Oecologia 125:249–257.
HOLBROOK, K. M., SMITH, T. B. & HARDESTY, B. D. 2002. Long-distance movements of frugivorous rainforest hornbills. Ecography 25:745–749.
KANNAN, R. & JAMES, D. A. 1999. Fruiting phenology and the conservation of the Great Pied Hornbill (Buceros bicornis) in the Western Ghats of Southern India. Biotropica 31:167–177.
KARR, J. R. 1976. Seasonality, resource availability, and community diversity in tropical bird communities. American Naturalist 110:973–994.
KEMP, A. C. 2001. Family Bucerotidae (Hornbills). Pp. 436–523 in del Hoyo, J., Elliott, A., & Sargatal, J. (eds.). Handbook of the birds of the World. Vol. 6. Mousebirds to hornbills. Lynx Edicions, Barcelona.
KINNAIRD, M. F. & O’BRIEN, T. G. 1999. Breeding ecology of the Sulawesi Red-Knobbed Hornbill Aceros cassidix. Ibis 141:60–69.
KINNAIRD, M. F. & O’BRIEN, T. G. 2005. Fast foods of the forest: the influence of figs on primates and hornbills across Wallace's line. Pp. 155–184 in Dew, J. L. & Boubli, J. P. (eds.). Tropical fruits and frugivores. Springer, the Netherlands.
KINNAIRD, M. F. & O’BRIEN, T. G. 2008. The ecology and conservation of Asian hornbills: farmers of the forest. University of Chicago Press, Chicago. 315 pp.
KITAMURA, S., THONG-AREE, S., MADSRI, S. & POONSWAD, P. 2011. Characteristics of hornbill-dispersed fruits in lowland dipterocarp forests of southern Thailand. The Raffles Bulletin of Zoology 24:137–147.
LAMBERT, F. R. & MARSHALL, A. G. 1991. Keystone characteristics of bird-dispersed Ficus in a Malaysian lowland rain forest. Journal of Ecology 79:793–809.
LAMPERTI, A. M. 2004. Aspects of the seed dispersal ecology of Ceratogymna hornbills in the Dja Reserve, Cameroon. MA Thesis, San Francisco State University.
LEIGHTON, M. & LEIGHTON, D. R. 1983. Vertebrate responses to fruiting seasonality within a Bornean rain forest. Pp. 181–196 in Sutton, S. L., Whitmore, T. C. & Chadwick, A. C. (eds.). Tropical rain forest: ecology and management. Blackwell Scientific Publications, Oxford.
MARTIN, T. E. 1987. Food as a limit on breeding birds: a life-history perspective. Annual Review of Ecology and Systematics 18:453–487.
MARTIN, T. E. 1993. Nest predation and nest sites. BioScience 43:523–532.
MCDOWELL, L. R. 2003. Minerals in animal and human nutrition. (Second edition). Elsevier, Amsterdam. 660 pp.
MCKEY, D. 1975. The ecology of coevolved seed dispersal systems. Pp. 159–191 in Gilbert, L. E. & Austin, P. H. (eds.). Coevolution of animals and plants. University of Texas Press, Austin.
MUCHAAL, P. K. & NGANDJUI, G. 1995. Wildlife populations in the western Dja Reserve (Cameroon): an assessment of the impact of village hunting and alternatives for sustainable utilization. Republic of Cameroon Ministry of Environment and Forests and ECOFAC (Conservation and Sustainable Utilization of Forest Ecosystems in Central Africa). Yaoundé, Cameroon.
MUCHAAL, P. K. & NGANDJUI, G. 1999. Impact of village hunting on wildlife populations in the Western Dja Reserve, Cameroon. Conservation Biology 13:385–396.
MURPHY, M. E. 1996. Nutrition and metabolism. Pp. 31–60 in Carey, C. (ed.). Avian energetics and nutritional ecology. Chapman & Hall, New York.
NAGER, R. G. 2006. The challenges of making eggs. Ardea-Wageningen 94.3:323.
O’BRIEN, T. G., KINNAIRD, M. F., DIERENFELD, E. S., CONKLIN-BRITTAIN, N. L., WRANGHAM, R. W. & SILVER, S. C. 1998. What's so special about figs? Nature 392:668.
OTTEN, B. A., OROSZ, S. E., AUGE, S. & FRAZIER, D. L. 2001. Mineral content of food items commonly ingested by keel-billed toucans (Ramphastos sulfuratus). Journal of Avian Medicine and Surgery 15:194–196.
ELMER, PERKIN. 1982. Analytical methods for atomic absorption spectrophotometry. Perkin Elmer, Norwalk. 300 pp.
POONSWAD, P., TSUJI, A. & JIRAWATKAVI, N. 2004. Estimation of nutrients delivered to nest inmates by four sympatric species of hornbills in Khao Yai National Park, Thailand. Ornithological Science 3:99–112.
POULIN, B., LEFEBVRE, G. & MCNEIL, R. 1992. Tropical avian phenology in relation to abundance and exploitation of food resources. Ecology 73:2295–2309.
POULSEN, J. R., CLARK, C. J. & SMITH, T. B. 2001. Seed dispersal by a diurnal primate community in the Dja Reserve, Cameroon. Journal of Tropical Ecology 17:787–808.
POULSEN, J. R., CLARK, C. J., CONNOR, E. F. & SMITH, T. B. 2002. Differential resource use by primates and hornbills: implications for seed dispersal. Ecology 83:228–240.
ROBBINS, C. T. 1993. Wildlife feeding and nutrition. Academic Press, New York. 352 pp.
RENDELL, W. B. & ROBERTSON, R. J. 1994. Cavity-entrance orientation and nest-site use by secondary hole-nesting birds. Journal of Field Ornithology 65:27–35.
RUBY, J., NATHAN, P. T., BALASINGH, J. & KUNZ, T. H. 2000. Chemical composition of fruits and leaves eaten by short-nosed fruit bat, Cynopterus sphinx. Journal of Chemical Ecology 26:2825–2841.
SCHOENER, T. W. 1968. The Anolis lizards of Bimini: resource partitioning in a complex fauna. Ecology 49:704–726.
SHANAHAN, M., SO, S., COMPTON, S. G. & CORLETT, R. 2001. Fig-eating by vertebrate frugivores: a global review. Biological Reviews 76:529–572.
SIBLY, R. M., WITT, C. C., WRIGHT, N. A., VENDITTI, C., JETZ, W. & BROWN, J. H. 2012. Energetics, lifestyle, and reproduction in birds. Proceedings of the National Academy of Sciences, USA 109:10937–10941.
STAUFFER, D. & SMITH, T. B. 2004. Breeding and nest site characteristics of the Black-casqued Hornbill Ceratogymna atrata and White-thighed Hornbill Ceratogymna cylindricus in south-central Cameroon. Ostrich 75:79–88.
STILES, E. W. 1993. The influence of pulp lipids on fruit preference by birds. Vegetatio 107/108:227–235.
STRICKLAND, J. D. H. & PARSON, T. R. 1972. A practical handbook of seawater analysis. Fisheries Board of Canada, Ottawa. 310 pp.
TERBORGH, J. 1986. Keystone plant resources in the tropical forest. Pp. 330–344 in Soulé, M. E. (ed.). Conservation biology: the science of scarcity and diversity. Sinauer, Sunderland.
TILGAR, V., MÄND, R. & MÄGI, M. 2002. Calcium shortage as a constraint on reproduction in great tits Parus major: a field experiment. Journal of Avian Biology 33:407–413.
WENDELN, M. C., RUNKLE, J. R. & KALKO, E. K. V. 2000. Nutritional values of 14 fig species and bat feeding preferences in Panama. Biotropica 32:489–501.
WHITNEY, K. D. & SMITH, T. B. 1998. Habitat use and resource tracking by African Ceratogymna hornbills: implications for seed dispersal and forest conservation. Animal Conservaton 1:107–117.
WHITNEY, K. D., FOGIEL, M. K., SMITH, T. B., PARKER, V. T. & STAUFFER, D. J. 1996. Dja Hornbill Project. EEP Hornbill Taxon Advisory Group Newsletter 2:25.
WHITNEY, K. D., FOGIEL, M. K., LAMPERTI, A. M., HOLBROOK, K. M., STAUFFER, D. J., HARDESTY, B. D., PARKER, V. T. & SMITH, T. B. 1998. Seed dispersal by Ceratogymna hornbills in the Dja Reserve, Cameroon. Journal of Tropical Ecology 14:351–371.