[en] Background and aims – Most tree species with aril-covered seeds are assumed to be dispersed by frugivores. However, the number of studied African rainforest plant species remains low. This study focused on Afzelia bipindensis, an important timber species, which produces seeds partly covered by an aril. Specifically, this study aimed to: (1) identify the dispersers and the predators of A. bipindensis seeds, (2) characterize the role of those dispersers and predators in the regeneration process, and (3) understand the role of the aril in seed germination in relation to the feeding behaviour of the identified dispersers.
Methods – The study took place in a Gabonese evergreen rainforest in 2015 and in a Cameroonian semideciduous rainforest in 2016 and 2017. We conducted more than 100 hours of direct observations, and used camera traps to monitor animal activities for 3000 hours within the canopy and 10 000 hours on the ground under fruiting trees.
Key results – Three rodent taxa (Cricetomys emini, Funisciurus isabella and an undetermined species of Muridae) were mainly observed interacting with the seeds but neither birds nor monkeys were observed. Rodents removed more than 90% of the seeds, after detaching the aril, to probably cache them in burrows or superficial caches. Seeds from which we manually removed the aril (mimicking rodent behaviour) had a higher germination rate.
Conclusions – Rodents may play a more important role than expected in the dynamics of tree species producing aril-covered seeds.
Disciplines :
Environmental sciences & ecology
Author, co-author :
Evrard, Quentin ; Université de Liège - ULiège > Gembloux Agro-Bio Tech - TERRA Teaching and Research Center > Forest is Life
Hardy, Olivier; Université Libre de Bruxelles - ULB > Evolutionary Biology and Ecology Unit
Tagg, Nikki; Royal Zoological Society of Antwerp > Centre for Research and Conservation > Projet Grands Singes
Doucet, Jean-Louis ; Université de Liège - ULiège > Département GxABT > Laboratoire de Foresterie des régions trop. et subtropicales
Language :
English
Title :
Removal and predation of aril-covered seeds: the case of Afzelia bipindensis (Fabaceae - Detarioidae)
Aliyu B., Adamu H., Moltchanova E., Forget P.-M., Chapman H. (2014) The interplay of habitat and seed type on scatterhoarding behavior in a fragmented Afromontane forest landscape. Biotropica 46(3): 264–267. https://doi.org/10.1111/btp.12110
Allaer F. (2017) Différenciation d’espèce cryptiques dans le genre Afzelia (Leguminosae – Detarioideae). Master Thesis, University of Liège – Gembloux Agro-Bio Tech, Gembloux, Belgium.
Bationo B.A., Boussim I.J., Ouédraogo S.J. (2000) Afzelia afri-cana Sm. (Caesalpiniaceae): étude de la prédation des graines dans une savane boisée du Burkina Faso. Bois et Forêts des Tropiques 264(2): 55–56.
Beaune D., Bollache L., Bretagnolle F., Fruth B. (2012) Dung beetles are critical in preventing post-dispersal seed removal by rodents in Congo rain forest. Journal of Tropical Ecology 28(5): 507–510. https://doi.org/10.1017/S0266467412000466
Beaune D., Bretagnolle F., Bollache L., Bourson C., Hohmann G., Fruth B. (2013a) Ecological services performed by the bonobo (Pan paniscus): seed dispersal effectiveness in tropical forest. Journal of Tropical Ecology 29(5): 367–380. https://doi.org/10.1017/S0266467413000515
Beaune D., Bretagnolle F., Bollache L., Hohmann G., Surbeck M., Fruth B. (2013b) Seed dispersal strategies and the threat of defaunation in a Congo forest. Biodiversity and Conservation 22(1): 225–238. https://doi.org/10.1007/s10531-012-0416-x
Beckman N.G., Rogers H.S. (2013) Consequences of seed dispersal for plant recruitment in tropical forests: interactions within the seedscape. Biotropica 45(6): 666–681. https://doi.org/10.1111/btp.12071
Boissier O., Bouiges A., Mendoza I., Feer F., Forget P.-M. (2014) Rapid assessment of seed removal and frugivore activity as a tool for monitoring the health status of tropical forests. Biotropica 46(5): 633–641. https://doi.org/10.1111/btp.12134
Bourland N., Kouadio Y. L., Lejeune P., Sonké B., Philippart J., Daïnou K., Fétéké F., Doucet J.-L. (2012) Ecology of Pericop-sis elata (Fabaceae), an endangered timber species in southeastern Cameroon. Biotropica 44(6): 840–847. https://doi. org/10.1111/j.1744-7429.2012.00874.x
Cadman M., González-Talaván A. (eds) (2014) Publishing camera trap data, a best practice guide. Contributed by Athreya V., Chavan V., Ghosh M., Hanssen F., Harihar A., Hirsch T., Lind-gaard A., Mathur V.B., Mehlum F., Pandav B., Talukdar G., Vang R. Copenhagen, Global Biodiversity Information Facility. Available at http://www.gbif.org/orc/?doc_id=6045 [accessed 16 Dec. 2018].
Chapman H.M., Goldson S.L., Beck J. (2010) Postdispersal removal and germination of seed dispersed by Cercopithecus nic-titans in a West African montane forest. Folia Primatologica; International Journal of Primatology 81(1): 41–50. https://doi. org/10.1159/000283309
Chudnoff M. (1980) Tropical timbers of the world. Agricultural Handbook No 607. Washington D.C., USDA Forest Service.
CTFT (Centre Technique Forestier Tropical) (1980) Doussié. Bois et Forêts des Tropiques 189: 37–54.
Davies S.J., Ashton P.S. (1999) Phenology and fecundity in 11 sympatric pioneer species of Macaranga (Euphorbiaceae) in Borneo. American Journal of Botany 86(12): 1786–1795. https://doi.org/10.2307/2656675
De Steven D., Putz F.E. (1984) Impact of mammals on early recruitment of a tropical canopy tree, Dipteryx panamensis, in Panama. Oikos 43(2): 207–216. https://doi.org/10.2307/3544770
Demarquez B., Jeanmart P. (2004) Plan d’aménagement de la Concession Forestière sous Aménagement Durable de la société Thanry-CEB 2000–2025. Lastoursville, Gabon
Donkpegan A., Hardy O.J., Lejeune P., Oumorou M., Daïnou K., Doucet J.-L. (2014) Un complexe d’espèces d’Afzelia des forêts africaines d’intérêt économique et écologique (synthèse biblio-graphique). Biotechnology, Agronomy, Society and Environment 18(2): 233–246.
Donkpegan A. (2017) Histoire Evolutive du complexe Afzelia Smith (Leguminosae – Caesalpinioidae) dans les ecosystèmes forestiers et savanicoles d’Afrique tropicale. PhD Thesis, Université de Liège – Gembloux Agro-Bio Tech, Gembloux, Belgium.
Doucet J.-L. (2003) L’alliance délicate de la gestion forestière et de la biodiversité dans les forêts du centre du Gabon. PhD Thesis, FUSAGx, Gembloux, Belgium.
Douh C., Daïnou K., Loumeto J. J., Moutsambote J.-M., Fayolle A., Tosso F., Forni E., Gourlet-Fleury S., Doucet J.-L. (2018) Soil seed bank characteristics in two central African forest types and implications for forest restoration. Forest Ecology and Management 409(1): 766–776. https://doi.org/10.1016/j. foreco.2017.12.012
Evrard Q., Haurez B., Doucet J.-L. (2017) Le rôle des rongeurs dans la dispersion des diaspores en milieu forestier (synthèse biblio-graphique). Biotechnologie, Agronomie, Société et Environnement 21(1): 66–79. https://doi.org/10.25518/1780-4507.13448
Fonteyn D. (2017) Impacts comparés de trois régimes fonciers sur la biodiversité et la biomasse forestière au sud-est du Cameroun. Master Thesis, Université de Liège – Gembloux Agro-Bio Tech, Gembloux, Belgium.
Forget P.-M., Milleron T. (1991) Evidence for secondary seed dispersal by rodents in Panama. Oecologia 87(4): 596–599. https://doi.org/10.1007/BF00320426
Gálvez D., Kranstauber B., Kays R.W., Jansen P.A. (2009) Scatter-hoarding by the Central American agouti: a test of optimal cache spacing theory. Animal Behaviour 78(6): 1327–1333. https://doi.org/10.1016/j.anbehav.2009.08.015
Gartlan J.S., Struhsaker T.T. (1972) Polyspecific associations and niche separation of rain-forest anthropoids in Cameroon, West Africa. Journal of Zoology 168(2): 221–266. https://doi. org/10.1111/j.1469-7998.1972.tb01348.x
Gathua M. (1992) The importance of animals in the survival of a canopy tree, pod mahogany (Afzelia quanzensis Welw) in the Arabuko-Sokoke forest, Kenya. Master Thesis, University of Nairobi, Nairobi, Kenya.
Gathua M. (2000) The effects of primates and squirrels on seed survival of a canopy tree, Afzelia quanzensis, in Arabuko-Sokoke Forest, Kenya. Biotropica 32(1): 127–132. https://doi. org/10.1111/j.1744-7429.2000.tb00455.x
Gauthier-Hion A., Duplantier J.-M., Quris R., Feer F., Sourd C., Decoux J.-P., Dubost G., Emmons L., Erard C., Hecketsweiler P., Moungazi A., Roussilhon C., Thiollay J.-M. (1985) Fruit characters as a basis of fruit choice and seed dispersal in a tropical forest vertebrate community. Oecologia 65(3): 324–337. https://doi.org/10.1007/BF00378906
Gérard J., Louppe D. (2011) Afzelia bipindensis Harms. [Inter-net] Record from PROTA4U. Lemmens R.H.M.J., Louppe D., Oteng-Amoako A.A. (Editors). PROTA (Plant Resources of Tropical Africa/Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Available at http://www.prota4u.org/search.asp [accessed 1 Sep. 2018].
Gilbert G.S., Webb C.O. (2007) Phylogenetic signal in plant path-ogen-host range. Proceedings of the National Academy of Sciences of the United States of America 104(12): 4979–4983. https://doi.org/10.1073/pnas.0607968104
Goodwin R.M. (2007) Behavior and ecology of the Mona Monkey in the seasonally dry Lama Forest, Republic of Bénin. New York, University of New York.
Harrison M.J.S. (1983) Optimal Foraging Strategies in the Diet of the green monkey, Cercopithecus sabaeus, at Mt. Assirik, Senegal. International Journal of Primatology 5(5): 435–471. https://doi.org/10.1007/BF02692269
Haugaasen J.M.T., Haugaasen T., Peres C.A., Gribel R., Wegge P. (2010) Seed dispersal of the Brazil nut tree (Bertholletia ex-celsa) by scatter-hoarding rodents in a central Amazonian forest. Journal of Tropical Ecology 26(3): 251–262. https://doi. org/10.1017/S0266467410000027
Haurez B., Petre C.-A., Doucet J.-L. (2013) Impacts of logging and hunting on western lowland gorilla (Gorilla gorilla gorilla) populations and consequences for forest regeneration. A review. Biotechnology, Agronomy, Society and Environment 17(2): 364–372.
Haurez B., Dainou K., Tagg N., Petre C.A., Doucet J.-L. (2015) The role of great apes in seed dispersal of the tropical forest tree species Dacryodes normandii (Burseraceae) in Gabon. Journal of Tropical Ecology 31(5): 395–402. https://doi.org/10.1017/S0266467415000322
Haurez B., Tagg N., Petre C.-A., Brostaux Y., Boubady A., Doucet J.-L. (2017) Seed dispersal effectiveness of the western lowland gorilla (Gorilla gorilla gorilla) in Gabon. African Journal of Ecology 56(2): 185–193. https://doi.org/10.1111/aje.12449
Hirsch B.T., Kays R., Pereira V.E., Jansen P.A. (2012) Directed seed dispersal towards areas with low conspecific tree density by a scatter-hoarding rodent. Ecology Letters 15(12): 1423–1429. https://doi.org/10.1111/ele.12000
Jansen P.A., Bartholomeus M., Bongers F., Elzinga J.A., den Ouden J., Van Wieren S.E. (2002) The role of seed size in dispersal by scatter-hoarding rodent. In: Levey D.J., Silva W.R., Galetti M. (eds) Seed dispersal and frugivory: ecology, evolution and conservation. Third International Symposium-Workshop on Frugivores and Seed Dispersal, São Pedro, Brazil, 6–11 August 2000: 209–225. New York, CABI Publishing. https://doi. org/10.1079/9780851995250.0209
Jansen P.A., Bongers F., Hemerik L. (2004) Seed mass and mast seeding enhance dispersal by a neotropical scatter-hoarding rodent. Ecological Monographs 74(4): 569–589. https://doi. org/10.1890/03-4042
Jansen P.A., Hirsch B.T., Emsens W.-J., Zamora-Gutierrez V., Wikelski M., Kays R. (2012) Thieving rodents as substitute dispersers of megafaunal seeds. Proceedings of the National Academy of Sciences of the United States of America 109(31): 12610–12615. https://doi.org/10.1073/pnas.1205184109
Jansen P.A., Ahumada J.A., Fegraus E.H., O’Brien T.G. (2014) TEAM: a standardized camera trap survey to monitor terrestrial vertebrate communities in tropical forests. In: Meek P.D., Ballard A.G., Banks P.B., Claridge A.W., Fleming P.J.S., Sanderson J.G., Swann D.E. (eds) Camera trapping: wildlife research and management: 263–270. Melbourne, CSIRO Publishing.
Janzen D.H. (1971) Seed predation by animals. Annual Review of Ecology and Systematics 2: 465–492. https://doi.org/10.1146/annurev.es.02.110171.002341
Janzen D.H., Fellows L.E., Waterman P.G. (1990) What protects Lonchocarpus (Leguminosae) seeds in a Costa Rican dry forest? Biotropica 22(3): 272–285. https://doi.org/10.2307/2388538
Kankam B.O., Oduro W. (2009) Frugivores and fruit removal of Antiaris toxicaria (Moraceae) at Bia Biosphere Reserve, Ghana. Journal of Tropical Ecology 25(2): 201–204. https://doi. org/10.1017/S0266467409005835
Kitamura S. (2011) Frugivory and seed dispersal by hornbills (Bu-cerotidae) in tropical forests. Acta Oecologica 37(6): 531–541. https://doi.org/10.1016/j.actao.2011.01.015
Koerner S.E., Poulsen J.R., Blanchard E.J., Okouyi J., Clark C.J. (2016) Vertebrate community composition and diversity declines along a defaunation gradient radiating from rural villages in Gabon. Journal of Applied Ecology 54(3): 805–814. https://doi.org/10.1111/1365-2664.12798
Kouadio Y.L., Doucet J.-L. (2009) Etude du comportement de Bail-lonella toxisperma Pierre (moabi) dans les trouées d’abattage enrichies. Biotechnologie, Agronomie, Société et Environnement 13(2): 317–324.
Liu X., Liang M., Etienne R.S., Wang Y., Staehelin C., Yu S. (2012) Experimental evidence for a phylogenetic Janzen-Connell effect in a subtropical forest. Ecology Letters 15(2): 111–118. https://doi.org/10.1111/j.1461-0248.2011.01715.x
Luo Y., Yang Z., Steele M.A., Zang Z., Stratford J.A., Zhang H. (2014) Hoarding without reward: rodent responses to repeated episodes of complete cache loss. Behavioural Processes 106: 36–43. https://doi.org/10.1016/j.beproc.2014.04.005
Mapangou M. (2004) Caractéristiques physiques du Gabon. Available at http://bch-cbd.naturalsciences.be/gabon/gabondef/con-tribution/documentsnat/strategienat/part1chapa.htm [accessed 15 Jul. 2018].
Markl J.S., Schleuning M., Forget P.-M., Jordano P., Lambert J.E., Traveset A., Wright J., Böhning-Gaese K. (2012) Meta-analysis of the effects of human disturbance on seed dispersal by animals. Conservation Biology 26(6): 1072–1081. https://doi. org/10.1111/j.1523-1739.2012.01927.x
Meek P.D., Ballard G., Claridge A., Kays R., Moseby K., O’Brien T., O’Connell A., Sanderson J., Swann D.E., Tobler M., Townsend S. (2014) Recommended guiding principles for reporting on camera trapping research. Biodiversity and Conservation 23(9): 2321–2343. https://doi.org/10.1007/s10531-014-0712-8
Meunier Q., Moumbogou C., Doucet J.-L. (2015) Les arbres utiles du Gabon. Gembloux, Les Presses agronomiques de Gembloux.
Mohd Azlan J., Lading E. (2006) Camera trapping and conservation in Lambir Hills National Park, Sarawak. The Raffles Bulletin of Zoology 54(2): 469–475.
Moore J.E., McEuen A.B., Swihart R.K., Contreras T.A., Steele M.A. (2007) Determinants of seed removal distance by scatter-hoarding rodents in deciduous forests. Ecology 88(10): 2529– 2540. https://doi.org/10.1890/07-0247.1
Moupela C., Doucet J.-L., Dainou K., Tagg N., Bourland N., Vermeulen C. (2013) Dispersal and predation of diaspores of Coula edulis Baill. in an evergreen forest of Gabon. African Journal of Ecology 52(1): 88–96. https://doi.org/10.1111/aje.12089
Muchaal P. K., Ngandjui G. (1999) Impact of village hunting on wildlife populations in the western Dja Reserve, Cameroon. Conservation Biology 13(2): 385–396. https://doi.org/10.1046/j.1523-1739.1999.013002385.x
Mugerwa B., Sheil D., Ssekiranda P., van Heist M., Ezuma P. (2012) A camera trap assessment of terrestrial vertebrates in Bwindi Impenetrable National Park, Uganda. African Journal of Ecology 51(1): 21–31. https://doi.org/10.1111/aje.12004
Muñoz A., Bonal R. (2011) Linking seed dispersal to cache protection strategies. Journal of Ecology 99(4): 1016–1025. https://doi.org/10.1111/j.1365-2745.2011.01818.x
Nishihara T. (1995) Feeding ecology of western lowland gorillas in the Nouabalé-Ndoki National Park, Congo. Primates 36(2): 151–168. https://doi.org/10.1007/BF02381342
Nature+, Pallisco (2012) Evaluation de l’état des populations des essences exploitées par la société Pallisco et des décisions prises en matière d’aménagement – Deuxième version. Gembloux (Belgium), Laboratoire de Foresterie des Régions tropicales et subtropicales – Ulg Gx ABT.
Novotny V., Basset Y., Miller S.E., Weiblen G.D., Bremer B., Cizek L., Drozd P. (2002) Low host specificity of herbivorous insects in a tropical forest. Nature 416(6883): 841–844. https://doi. org/10.1038/416841a
Nyiramana A. (2012) Production de fruits, dissémination et devenir des grains de Carapa grandiflora Sprague (Meliaceae) dans le Parc National de Nyungwe, Rwanda. PhD Thesis, Muséum national d’Histoire naturelle de Paris, Paris, France.
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(6): 787–808. https://doi.org/10.1017/S0266467401001602
Poulsen J.R., Clark C.J., Connor E.F., Smith T.B. (2002) Differential ressource use by primates and hornbills: implications for seed dispersal. Ecology 83(1): 228–240.
Ridley H.N. (1930) The dispersal of plants throughout the world. Ashford, Reeve.
Rogers M.E, Maisels F., Williamson E.A., Fernandez M., Tutin C.E.G. (1990) Gorilla diet in the Lopé Reserve, Gabon: a nutritional analysis. Oecologia 84(3): 326–339. https://doi.org/10.1007/BF00329756
Rosin C., Poulsen J.R. (2017) Telemetric tracking of scatterhoarding and seed fate in a Central African forest. Biotropica 49(2): 170–176. https://doi.org/10.1111/btp.12410
Rovero F., Tobler M., Sanderson J. (2010) Camera trapping for inventorying terrestrial vertebrates. In: Eymann J., Degreef J., Häuser C., Monje J.C., Samyn Y., VandenSpiegel D. (eds) ABC Taxa vol. 8 – Manual on field recording techniques and protocols for All Taxa Biodiversity Inventories: 100–128.
Russo S.E. (2003) Responses of dispersal agents to tree and fruit traits in Virola calophylla (Myristicaceae): implications for selection. Oecologia 136(1): 80–87. https://doi.org/10.1007/s00442-003-1239-y
Schupp E.W. (1993) Quantity, quality and the effectiveness of seed dispersal by animals. Vegetatio 107/108: 15–29. https://doi.org/10.1007/978-94-011-1749-4_2
Schupp E.W., Jordano P. (2011) The full path of Janzen-Connell effects: genetic tracking of seeds to adult plant recruitment. Molecular Ecology 20(19): 3953–3955. https://doi.org/10.1111/j.1365-294X.2011.05202.x
Serckx A., Kühl H.S., Beudels-Jamar R.C., Poncin P., Bastin J.-F., Huynen M.-C. (2015) Feeding ecology of bonobos living in for-est-savannah mosaics: diet seasonal variation and importance of fallback foods. American Journal of Primatology 77(8): 1098– 2345. https://doi.org/10.1002/ajp.22425
Snow D.W. (1981) Tropical frugivorous birds and their food plants: a world survey. Biotropica 13(1): 1–14. https://doi. org/10.2307/2387865
Soné K. (2004) Effects of nest hoarding on foraging behavior of two species of Apodemus mice, A. speciosus and A. argenteus (Rodentia: Muridae). Journal of Forest Research 9(3): 255– 259. https://doi.org/10.1007/s10310-004-0077-z
Soné K., Kohno A. (1999) Acorn hoarding by the field mouse, Apodemus speciosus Temminck (Rodentia: Muridae). Journal of Forest Research 4(2): 167–175. https://doi.org/10.1007/BF02762243
Sonké B. (1998) Etudes floristiques et structurales des forêts de la Réserve de Faune du Dja (Cameroun). PhD Thesis, Université Libre de Bruxelles, Bruxelles, Belgium.
Sork V.L. (1987) Effects of predation and light on seedling establishment in Gustavia superba. Ecology 68(5): 1341–1350. htt-ps://doi.org/10.2307/1939218
Steele M.A., Bugdal M., Yuan A., Bartlow A., Buzalewski J., Li-chti N., Swihart R. (2011) Cache placement, pilfering, and a recovery advantage in a seed-dispersing rodent: could predation of scatter hoarders contribute to seedling establishment? Acta Oecologica 37(6): 554–560. https://doi.org/10.1016/j.ac-tao.2011.05.002
Steele M.A., Contreras T.A., Hadj-Chikh L.Z., Agosta S.J., Small-wood P.D., Tomlinson C.N. (2014) Do scatter hoarders trade off increased predation risks for lower rates of cache pilferage? Behavioral Ecology 25(1): 206–215. https://doi.org/10.1093/beheco/art107
Swartz M.J., Jenkins S.H., Dochtermann N.A. (2010) Coexisting desert rodents differ in selection of microhabitats for cache placement and pilferage. Journal of Mammalogy 91(5): 1261– 1268. https://doi.org/10.1644/09-MAMM-A-280.1
TerEA (Terre Environnement Aménagement) (2007) Résumé public du plan d’aménagement. Compagnie Equatoriale des bois – Precious Woods Gabon. Lastoursville, Gabon. 1–31. Available at http://www.preciouswoods.com/domains/preciouswoods_com/data/free_docs/Re%CC%81sume%CC%81_public_Plan_ dAme%CC%81nagement_CFAD_Precious_Woods_-_CEB_2. pdf [accessed 28 May 2019].
Tosso F., Cherchye G., Hardy O.J., Daïnou K., Lognay G., Tagg N., Haurez B., Souza A., Heuskin S., Doucet J.-L. (2017) Characterization of animal communities involved in seed dispersal and predation of Guibourtia tessmannii (Harms) J.Léonard, a species newly listed on Appendix II of CITES. African Journal of Ecology 56(3): 468–476. https://doi.org/10.1111/aje.12480
Tutin C.E.G., Fernandez M. (1993) Composition of the diet of chimpanzees and comparisons with that of sympatric lowland gorillas in the Lopé Reserve, Gabon. American Journal of Primatology 30(3): 195–211. https://doi.org/10.1002/ajp.1350300305
Trolliet F., Forget P.-M., Doucet J.-L., Gillet J.-F., Hambuckers A. (2017) Frugivorous birds influence the spatial organization of tropical forests through the generation of seedling recruitment foci under zoochoric trees. Acta Oecologica 85: 69–76. https://doi.org/10.1016/j.actao.2017.09.010
Vleminckx J., Morin-Rivat J., Biwolé A.B., Daïnou K., Gillet J.-F., Doucet J.-L., Drouet T., Hardy O.J. (2014) Soil charcoal to assess the impacts of past human disturbances on tropical forests. PLoS ONE 9(11): e108121. https://doi.org/10.1371/journal. pone.0108121
Watts D.P., Potts K.B., Lwanga J.S., Mitani J.C. (2012) Diet of chimpanzees (Pan troglodytes schweinfurthii) at Ngogo, Kibale National Park, Uganda, 2. Temporal variation and fallback foods. American Journal of Primatology 74(2): 130–144. htt-ps://doi.org/10.1002/ajp.21015
Zhang H., Cheng J., Xiao Z., Zhang Z. (2008) Effects of seed abundance on seed scatter-hoarding of Edward’s rat (Leopoldamys edwardsi Muridae) at the individual level. Oecologia 158(1): 57–63. https://doi.org/10.1007/s00442-008-1114-y