Artículo

La versión final de este artículo es de uso interno de la institución.
Consulte el artículo en la página del editor
Consulte la política de Acceso Abierto del editor

Abstract:

We studied the effect of group size on the proportion of time that greater rheas, Rhea americana, allocated to vigilance and feeding during the non-breeding season. We tested whether: (1) the proportion of time that one bird allocates to vigilance (individual vigilance) decreases with group size, and (2) the proportion of time that at least one bird of the group is vigilant (collective vigilance) increases with group size. We analyzed video-recordings of birds that were foraging alone or in groups from two to 12 birds. The proportion of time allocated to individual vigilance decreased and the proportion of time spent feeding increased with group size. In both cases the main significant difference was between birds foraging alone and in groups. Collective vigilance did not vary with group size and it was lower than expected if vigilance bouts were random or sequential. Our results indicate that rheas foraging in large groups would not receive the benefit of an increase in collective vigilance, although they could still benefit from a reduction of predation risk by the dilution effect.

Registro:

Documento: Artículo
Título:Effect of group size on individual and collective vigilance in greater rheas
Autor:Fernández, G.J.; Capurro, A.F.; Reboreda, J.C.
Filiación:Depto. de Ecologia, Genet. y Evol., Fac. de Ciencias Exactas y Naturales, Pabellón II Cd. Universitaria, Buenos Aires, Argentina
Laboratorio de Ecología, Prog. de Ecologia Matemat., Universidad Nacional de Luján, Provincia de Buenos Aires, Argentina
Depto. de Ecologia, Genet. y Evol., Fac. de Ciencias Exactas y Naturales, Pabellón II Cd. Universitaria, C1428EHA Buenos Aires, Argentina
Palabras clave:feeding behavior; group size; time allocation; vigilance; Aves; Rhea; Rhea americana; Rheiformes
Año:2003
Volumen:109
Número:5
Página de inicio:413
Página de fin:425
DOI: http://dx.doi.org/10.1046/j.1439-0310.2003.00887.x
Título revista:Ethology
Título revista abreviado:Ethology
ISSN:01791613
CODEN:ETHOE
Registro:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01791613_v109_n5_p413_Fernandez

Referencias:

  • Bednekoff, P.A., Lima, S.L., Re-examining safety in numbers: Interactions between risk dilution and collective detection depend upon predator targeting behaviour (1998) Proc. R. Soc. Lond. B, 265, pp. 2021-2026
  • Bertram, B.C.R., Living in groups: Predators and preys (1978) Behavioural Ecology: An Evolutionary Approach, pp. 64-96. , (Krebs, J. R. & Davies, N. B., eds). Blackwell Scientific Publications, Oxford
  • Bertram, B.C.R., Vigilance and group size in ostriches (1980) Anim. Behav., 28, pp. 278-286
  • Caraco, T., Time budgeting and group size: A test of theory (1979) Ecology, 60, pp. 618-627
  • Cézilly, F., Brun, B., Surveillance et picorage chez la tourterelle rieuse, Streptotelia risoria: Effets de la presence d'un congenere et de la dispersion des graines (1989) Behaviour, 110, pp. 146-160
  • Clark, C.W., Mangel, M., The evolutionary advantages of group foraging (1986) Theor. Pop. Biol., 30, pp. 45-75
  • Dehn, M.M., Vigilance for predators: Detection and dilution effects (1990) Behav. Ecol. Sociobiol., 26, pp. 337-342
  • Elgar, M.A., Predator vigilance and group size in mammals and birds: A critical review of the empirical evidence (1989) Biol. Rev., 64, pp. 13-33
  • Elgar, M.A., Burren, P.J., Posen, M., Vigilance and perception of flock size in foraging house sparrows (Passer domesticus) (1984) Behaviour, 52, pp. 457-472
  • Ferrière, R., Cazelles, B., Cézilly, F., Desportes, J.-P., Predictability and caos in bird vigilant behaviour (1996) Anim. Behav., 57, pp. 497-500
  • Ferrière, R., Cazelles, B., Cézilly, F., Desportes, J.-P., Predictability, caos and coordination in bird vigilant behaviour (1999) Anim. Behav., 52, pp. 457-472
  • Fitzgibbon, C.D., A cost to individuals with reduced vigilance in groups of Thompsonis Gazelles hunted by cheetahs (1988) Anim. Behav., 37, pp. 508-510
  • Hamilton, W.D., Geometry for the selfish herd (1971) J. Theor. Biol., 31, pp. 295-311
  • Hammer, W.M., Parrish, J.K., Is the sum of the parts equals to the whole? The conflict between individuality and group membership (1998) Animal Groups in Three Dimensions, pp. 165-172. , (Parrish, J. K. & Hammer, W. M., eds). Cambridge Univ. Press, Cambridge
  • Hudson, W.H., (1920) Birds of La Plata, , J.M. Dent, London
  • Jarman, P., Group size and activity in eastern grey kangaroos (1987) Anim. Behav., 35, pp. 1044-1050
  • Lehner, P.N., (1998) Handbook of Ethological Methods, , Cambridge Univ. Press, Cambridge
  • Lima, S.L., Back to the basics of anti-predatory vigilance: The group size effect (1995) Anim. Behav., 49, pp. 11-20
  • Lima, S.L., Dill, L.M., Behavioral decisions made under the risk of predation: A review and prospectus (1990) Can. J. Zool., 68, pp. 619-640
  • Lima, S.L., Zollner, P.A., Bednekoff, P.A., Predation, scramble competition, and the vigilance group size effect in dark-eyed juncos (Junco hyemalis) (1999) Behav. Ecol. Sociobiol., 46, pp. 110-116
  • Lombardi, C.M., Feeding and vigilance in wild greater rhea harems (1995) Bird Behav., 10, pp. 29-35
  • Martella, M.B., Renison, D., Navarro, J.L., Vigilance in the greater rhea: Effects of vegetation height and group size (1995) J. Field Ornithol., 66, pp. 215-220
  • McGowan, K.J., Woolfenden, G.E., A sentinel system in the Florida scrub jay (1989) Anim. Behav., 37, pp. 1000-1006
  • McNamara, J.M., Houston, A.I., Evolutionary stable levels of vigilance as a function of group size (1992) Anim. Behav., 43, pp. 641-658
  • Monaghan, P., Metcalfe, N.B., Group foraging in wild brown hares: Effects of resource distribution and social status (1985) Anim. Behav., 33, pp. 993-999
  • Pulliam, H.R., On the advantages of flocking (1973) J. Theor. Biol., 38, pp. 419-422
  • Pulliam, H.R., Caraco, T., Living in groups: Is there an optimal group size? (1984) Behavioural Ecology: An Evolutionary Approach, pp. 122-147. , (Krebs, J. R. & Davies, N. B., eds). Blackwell Scientific Publications, Oxford
  • Quenette, P.Y., Gerard, J.F., From individual to collective vigilance in wild boars (Sus scofra) (1992) Can. J. Zool., 70, pp. 1632-1635
  • Rasa, O.A.E., Coordinated vigilance in dwarf mongooses family groups: The "Watchman' song" hypothesis and the costs of guarding (1986) Ethology, 71, pp. 340-344
  • Reboreda, J.C., Fernández, G.J., Sexual, seasonal and group size differences in the allocation of time between vigilance and feeding in the greater rhea, Rhea americana (1997) Ethology, 103, pp. 198-207
  • Ritz, D.A., Costs and benefits as a function of group size: Experiments on a swarming mysid, Paramesopodopsis rufa Fenton (1998) Animal Groups in Three Dimensions, pp. 194-206. , (Parrish, J. K. & Hammer, W. M., eds). Cambridge Univ. Press, Cambridge
  • Roberts, G., Why individual vigilance declines as group size increases (1996) Anim. Behav., 51, pp. 1077-1086
  • Ward, P., Why birds in flocks do not coordinate their vigilance periods (1985) J. Theor. Biol., 114, pp. 383-385
  • Yaber, M.C., Herrera, E.A., Vigilance, group size and social status in capybaras (1994) Anim. Behav., 48, pp. 1301-1307

Citas:

---------- APA ----------
Fernández, G.J., Capurro, A.F. & Reboreda, J.C. (2003) . Effect of group size on individual and collective vigilance in greater rheas. Ethology, 109(5), 413-425.
http://dx.doi.org/10.1046/j.1439-0310.2003.00887.x
---------- CHICAGO ----------
Fernández, G.J., Capurro, A.F., Reboreda, J.C. "Effect of group size on individual and collective vigilance in greater rheas" . Ethology 109, no. 5 (2003) : 413-425.
http://dx.doi.org/10.1046/j.1439-0310.2003.00887.x
---------- MLA ----------
Fernández, G.J., Capurro, A.F., Reboreda, J.C. "Effect of group size on individual and collective vigilance in greater rheas" . Ethology, vol. 109, no. 5, 2003, pp. 413-425.
http://dx.doi.org/10.1046/j.1439-0310.2003.00887.x
---------- VANCOUVER ----------
Fernández, G.J., Capurro, A.F., Reboreda, J.C. Effect of group size on individual and collective vigilance in greater rheas. Ethology. 2003;109(5):413-425.
http://dx.doi.org/10.1046/j.1439-0310.2003.00887.x