The feeding ecology of Ardea cocoi were analysed based on 29 herons captured on the Carabajal island (Santa Fe, 31°39'S, 60°42'W), determining the minimum sample, index of relative importance (IRI), size of prey, feeding efficiency, dietary selectivity, amplitude of the trophic niche, standardisation, circadian rhythm of feeding activity and habitat preference. The trophic spectrum was made up of 17 taxonomic entities, mainly fishes (IRI = 16,000), followed by mammals and amphibians (IRI = 8,000). The highest percentage of prey size was found in the interval 151→200 mm. The amplitude of the trophic niche ranged between 1.98 and 4.21, and the feeding efficiency between 89.9 and 99.9%. In relation to dietary selectivity, the correlation between abundance of prey in stomachs and abundance of prey in the study area yielded no significant results (rs = 0.078, P>0.001). The rhythm of feeding activity responded to the bell-shaped model. Aquatic vegetation was the unit of vegetation and environment selected more frequently.
Acosta CruzM., TorresO., and Mugica ValdésL. (1988) Subnicho trófico de Dendrocygna bicolor (Vieillot) (Aves: Anatidae) en dos arroceras de Cuba. Cienc. Biol., 19-20, 41–50.
2.
AmatJ.A. (1984) Las poblaciones de aves acuáticas en las lagunas andaluzas. Composición y diversidad durante un ciclo anual. Ardeola, 31, 61–79.
3.
AmatJ.A., and SoriguerR.C. (1981) Alimentación primaveral de la garcita bueyera. Doñana Acta Vertebrata, 8, 207–213.
4.
BrabataG., and CarmonaR. (1999) Conducta alimentaria de cuatro especies de aves playeras (Charadriiformes: Scolopacidae) en Chametla, B.C.S., México. Rev. Biol. Trop., 47, 239–243.
5.
BeltzerA.H. (2003) Aspectos tróficos de la comunidad de aves de los esteros del Iberá. In: AlabarezB.B. (ed.), Fauna del Iberá, pp. 257–272. Universidad Nacional del Nordeste, Corrientes, Argentina.
6.
BeltzerA.H. (2007) Relaciones tróficas y mecanismos de segregación ecológica entre las especies de garzas del valle de inundación del río Paraná (AVES: ARDEIDAE). Unpublished PhD Thesis, Universidad Nacional de La Plata, Facultad de Ciencias Naturales y Museo.
7.
BeltzerA.H., QuirogaM.A., and SchnackJ.A. (2005) Algunas ardeidas del valle de inundación del río Paraná: consideraciones sobre el nicho ecológico y mecanismos de aislamiento. INSUGEO, Tucumán, Miscelánea, 14, 499–526.
8.
BarrionuevoR., and MarcialR. (2006) Ecología trófica de la fauna acuática en el Manglar de san Pedro-Sechura. Universalia, 11, 44–56.
9.
BignalE.M., CurtisD.J., and MatthewsJ.L. (1988) Islau Land Types. Birds habitats and nature conservation. Part. 1: Land use and birds on Islay. NCC Chief Scientist Directorate, 809.
10.
BorreroJ.I., and Cruz-MillánC.A. (1982) Notas sobre la historia de la garza morena Ardea cocoi (Aves) en Colombia. Acta Biológica Colombiana, 1, 51–75.
11.
ButlerR. (1997) The Great Blue Heron.British Columbia, Canada.
12.
CanevariP., BlancoD.E., BucherE.H., CastroG., and DavidsonI. (1999) Los humedales de la Argentina. Clasificación, Situación Actual, Conservación y Legislación. Publicación No. 46. Wetlands International, Buenos Aires, Argentina.
13.
CrampS. (1998) The Complete Birds of the Western Palearctic on CD-ROM.Oxford University Press, Software Optimedia.
14.
de la PeñaM.R. (2001) Observaciones de campo en la alimentación de las aves. FAVE, 15, 99–107.
15.
DobosR. (1991) Two incidents of Great Blue Herons Feeding on Birds. Ontario Birds, 9, 87–88.
16.
DucommunM.P., QuirogaM.A., BeltzerA.H., and SchnackJ.A. (2008) Diet of Cattle Egrets in the flood valley of the paraná river, north Argentina. Avian Biol. Res., 1, 145–151.
17.
DuncanP. (1983) Determination of the use of habitat by horses in Mediterranean wetland. J. Anim. Ecol., 52, 93–109.
18.
GlahnJ.F., KingJ.O., and KingD.T. (1995) Impact of Great Blue Heron on channels catfish farms. J. World Aquaculture Soc., 26, 194–199.
19.
GlahnJ.F., TomsaT., and PreusserK.J. (1999) Impact of Great Blue Heron predation at trout-rearing facilities in the north-easter United States. North Am. J. Aquaculture, 61, 349–354.
20.
HancockJ., and KushlanJ. (2005) The Herons. Bird Families of the World.Oxford University Press inc., New York.
JacksicF. (1981) The guild structure of a community of predatory vertebrates in Central Chile. Oecología, 49, 21–28.
23.
JakubasD., and MioduszewskaA. (2005) Diet composition and food consumption of the Grey Heron (Ardea cinerea) from breeding colonies in northern Poland. Eur. J. Wildl. Res., 51, 191–198.
24.
JenniD.A. (1973) Regional variation in the food of Nestling Cattle Egrets. Auk, 90, 821–826.
25.
KreuzigerJ., and AchenbachE.L. (1998) Graureiher (Ardea cinerea) verschlingt Küken des Haubentauchers (Podiceps cristatus). Vogelwarte, 39, 301–302.
KushlanJ.A. (1976b) Feeding behavior of North American Herons. Auk, 93, 86–94.
28.
KushlanJ.A. (1978) Nonrigorous foraging by Robbing Egrets. Ecology, 59, 649–653.
29.
KushlanJ.A. (1981) Resource use strategies of wading birds. Wilson Bull., 93, 145–163.
30.
LekuonaJ.M., and CamposF. (1995) Le succès de reproduction du Héron cendré (Ardea cinerea) dans le Bassin d'Arcachon. Alauda, 63, 179–183.
31.
LekuonaJ.M. (2001) Variations in food composition and foraging behaviour of Grey heron Ardea cinerea in Aragon river (Northern Spain) during the breeding season. Anu. Ornit Navarra 1999, 6, 19–25.
32.
LekuonaJ.M., and CamposF. (1996) Seasonal dynarnics of Grey Herons on a large river in Spain. Col. Waterbirds, 19, 214–219.
33.
LekuonaJ.M., and CamposF. (1997) Composición de la dieta y comportamiento trófico de la Garza Real Ardea cinerea y de la Garza Imperial Ardea purpurea en el rio Aragón durante la época reproductora. Anuario Ornitológico de Navarra, 3, 21–28.
34.
LehmanF.C. (1960) Hallazgo de una colonia de Ardea cocoi en el Valle de Cauca. Nov. Colom., 1, 279.
35.
LevinsR. (1968) Evolution in changing environment.Princeton, New Jersey.
36.
MagurranA.E. (1989) La diversidad ecológica y su medición.Vedra, Barcelona, Spain.
37.
MarquissM., and LeitchA.F. (1990) The diet of Grey Herons Ardea cinerea breeding at Loch Leven, Scotland, and the importance of their predation on ducklings. Ibis, 132, 535–549.
38.
MauleA.G., and HortonH.F. (1984) Feeding ecology of walleye Sttizostedion vitreun viterun in the MidColumbia river, with emphasis on the interaction between valleye and juvenile anadromus fishes. Fish Bull., 82, 411–416.
39.
McCanchN. (2003) Grey Heron choking on Little Grebe. Brit. Birds, 96, 86.
40.
McNeilR., DrapeauP., and PierottiR. (1993) Nocturnality in colonial waterbirds: occurrence special adaptations and suspected benefits. Curr. Ornithol., 10, 187–246.
41.
ModdyD.T. (1970) A method for food samples from insectivorous birds. Auk, 87, 579.
42.
MoralesG., PinowskiJ., PachecoJ., MadrizM., and GómezF. (1981) Densidades poblacionales, flujo de energyía y hábitos alimentarios de las aves ictiófagas de los módulos de Apure, Venezuela. Acta Biol. Venez., 11, 1–45.
43.
Ntiamoa-BaidúY., PiersmaT., WiersmaP., PootM., BatleyP., and GordonC. (1998) Habitat selection, daily foraging routines and diet of waterbirds in coatal lagoon in Ghana. Ibis, 140, 89–103.
PiankaE.R. (1978) Evolutionary ecology.Harper's, New York.
46.
PinkasL., OliphantM.S., and IversonZ.L. (1971) Food habits of albacore bluefin tuna and bonito in California waters. Dept. of Fish and Game, Fish Bull., 152, 1–105.
47.
PistoriusP.A. (2008) Grey Heron (Ardea cinerea) Predation on the Aldabra White-throated Rail (Dryolimnas cuvieri aldabranus). Wilson J. Ornithol., 120, 631–632.
48.
RicklefsR.E. (1998) Invitación a la ecologyía. Economía de la naturaleza.Médica Panamericana, Buenos Aires, Argentina.
49.
RosenberK.V., and CooperR.J. (1990) Approaches to avian diet analysis. Stud. Avian Biol., 13, 80–90.
SodhiN.S. (1992) Food-nich relationships of five north Indian Herons. Forktail, 7, 125–130.
52.
SokalR.R., and RohlfF.J. (1979) Biometría. Principios y métos estadísticos en la investigación boilógica. Blume, Madrid, Spain.
53.
WiensJ.A. (1989) The Ecology of Bird Communities.Cambridge University Press, Cambridge.
54.
YanoskyA.A., EscalanteA., SchuchmannK., and KittleinM. (2000) Ecología de una Comunidad de Aves Vadeadoras en el Nordeste Argentino. In: CabreraE., MercolliC., and ResquinR. (eds.), Manejo de Fauna Silvestre en Amazonia y Latinoamérica, pp. 219–236. Cites-Py, Fundación Moisés Bertoni, University of Florida, Asunción.
