Vigilance and perception of flock size in foraging house sparrows (Passer domesticus L.)

Perception of flockmates is clearly important if individuals' vigilance behaviour depends as much on the behaviour of other individuals as on the flock size. We attempted to evaluate the importance of flockmate perception in the scanning behaviour of free-living house sparrows Passer domesticus by observing them at an artificial feeder. Typically, sparrows would await on an adjacent wall, where they could see all the birds in the feeder, before hopping down to forage. Individuals' inter-scan time increased with flock size, but when a barrier was placed across the feeder, preventing sparrows in the feeder from seeing the other side, individuals scanned according to the number of visible sparrows, rather than the total number in the feeder. When two smaller feeders were placed at different distances apart, individuals greater than 1.2 m apart scanned independently of each other.

[1]  N. Metcalfe.  The effects of mixed-species flocking on the vigilance of shorebirds: Who do they trust? , 1984, Animal Behaviour.

[2]  T. Caraco,et al.  Vigilance behaviour in house sparrow flocks , 1983, Animal Behaviour.

[3]  R. Underwood.  Vigilance Behaviour in Grazing African Antelopes , 1982 .

[4]  Mark A. Elgar,et al.  Flocking and predator surveillance in house sparrows: Test of an hypothesis , 1981, Animal Behaviour.

[5]  I. R. Inglis,et al.  Vigilance and Flock Size in Brent Geese: The Edge Effect , 1981 .

[6]  T. Caraco,et al.  Avian Time Budgets and Distance to Cover , 1980 .

[7]  Thomas Caraco,et al.  Avian flocking in the presence of a predator , 1980, Nature.

[8]  Influence of position in the flock and flock size on vigilance in the starling, Sturnus vulgaris , 1980, Animal Behaviour.

[9]  C. Barnard,et al.  Flock feeding and time budgets in the house sparrow (Passer domesticus L.) , 1980, Animal Behaviour.

[10]  B. Bertram,et al.  Vigilance and group size in ostriches , 1980, Animal Behaviour.

[11]  FLOCKING AS A POSSIBLE PREDATOR DEFENSE IN DARK-EYED JUNCOS , 1980 .

[12]  John Lazarus,et al.  The early warning function of flocking in birds: An experimental study with captive quelea , 1979, Animal Behaviour.

[13]  Thomas Caraco,et al.  Time Budgeting and Group Size: A Test of Theory , 1979 .

[14]  Robert E. Kenward,et al.  HAWKS AND DOVES: FACTORS AFFECTING SUCCESS AND SELECTION IN GOSHAWK ATTACKS ON WOODPIGEONS. , 1978 .

[15]  James N. M. Smith.  Feeding rates, search paths, and surveillance for predators in great-tailed grackle flocks , 1977 .

[16]  E. Wilson,et al.  Sociobiology: The New Synthesis , 1976 .

[17]  L. Underhill,et al.  Flocking as an anti-predator strategy in doves , 1975, Animal Behaviour.

[18]  D. Whitacre,et al.  Raptor Predation on Wintering Shorebirds , 1975 .

[19]  George V. N. Powell,et al.  Experimental analysis of the social value of flocking by starlings (Sturnus vulgaris) in relation to predation and foraging , 1974 .

[20]  H. Pulliam,et al.  On the advantages of flocking. , 1973, Journal of theoretical biology.

[21]  W. Hamilton.  Geometry for the selfish herd. , 1971, Journal of theoretical biology.

[22]  I. Vine,et al.  Risk of visual detection and pursuitby a predator and the selective advantage of flocking behaviour. , 1971, Journal of theoretical biology.