Abstract
Food supply and hatching asynchrony were manipulated for 90 broods of American kestrels (Falco sparverius) during 1989–1991. We measured the growth and mortality of nestlings within four treatment groups (asynchronous, synchronous, food-supplemented, unsupplemented) to test the brood reduction hypothesis of Lack (1947, 1954). Fledging success did not differ between synchronous and asynchronous broods when food was poor but consistent with the brood reduction hypothesis, nestlings died at a younger age in asynchronous broods. When food was supplemented, mortality did not occur in the synchronous broods but youngest nestlings still died in asynchronous nests despite apparently adequate food for the brood. Oldest nestlings in asynchronous broods fledged with a greater mass than their younger siblings, also consistent with Lack's hypothesis. Average nestling quality in synchronous broods was very dependent on food levels. Synchronous young that were supplemented were, on average, the heaviest of any treatment group but young from unsupplemented synchronous broods were the lightest. Overall, patterns of mortality and growth for kestrels support the brood reduction hypothesis when food is limited, but not when it is abundant. This food-dependent benefit of asynchrony in the nestling period is a prerequisite for facultatively adjusted hatching spans during laying.
Similar content being viewed by others
References
Amundsen T, Slagsvold T (1991a) Asynchronous hatching in the pied flycatcher: an experiment. Ecology 72: 797–804
Amundsen T, Slagsvold T (1991b) Hatching asynchrony: facilitating adaptive or maladaptive brood reduction? Proc Int Ornith Congr 20: 1707–1719
Amundsen T, Stokland JN (1988) Adaptive significance of brood reduction in the shag: a test of the brood reduction hypothesis. J Anim Ecol 57: 329–344
Anderson DJ (1989) The role of hatching asynchrony in siblicidal brood reduction of two booby species. Behav Ecol Sociobiol 25: 363–368
Anderson DJ, Budde C, Apanius V, Gomez JM, Bird DM, Weathers WW (1994) Prey size influences female competitive dominance in nestling American kestrels (Falco sparverius). Ecology 74: 367–376
Balgooyen TG (1976) Behaviour and ecology of the American kestrel (Falco sparverius) in the Sierra Nevada of California. Univ Calif Publ Zool 103: 1–83
Bird DM (1988) American kestrel. In: Palmer RS (eds) Handbook of North American birds, vol 4. Yale University Press, New Haven, pp 253–290
Bortolotti GR (1994) Effect of nest box size on nest-site preference and reproduction in American kestrels. J Raptor Res 28: 127–133
Bortolotti GR, Wiebe KL (1993) Incubation behaviour and hatching patterns in the American kestrel Falco sparverius. Ornis Scand 24: 41–47
Bortolotti GR, Wiebe KL, Iko WM (1991) Cannibalism of nestling American kestrels by their parents and siblings. Can J Zool 69: 1447–1453
Bryant DM (1978) Establishment of weight hierarchies in the broods of house martins Delichon urbica. Ibis 120: 16–26
Cade TJ (1982) Falcons of the world. Cornell University Press, Ithaca
Clark AB, Wilson DS (1981) Avian breeding adaptations, hatching asynchrony, brood reduction and nest failure. Q Rev Biol 56: 253–277
Clark AB, Wilson DS (1985) The onset of incubation in birds. Am Nat 125: 603–611
Daan S, Dijkstra C, Tinbergen JM (1990) Family planning in the kestrel (Falco tinnunculus): the ultimate control of covariation of laying date and clutch size. Behaviour 114: 83–116
Dijkstra C, Daan S, Buker JB (1990) Adaptive seasonal variation in the sex ratio of kestrel broods. Funct Ecol 4: 143–147
Drummond H, Osorno JL, Torres R, Chavelas CG, Larios HM (1991) Sexual size dimorphism and sibling competition: implications for avian sex ratios. Am Nat 138: 623–641
Forbes LS (1991) Hunger and food allocation in facultatively siblicidal ospreys. Behav Ecol Sociobiol 29: 185–195
Forbes LS, Mock DW (1994) Proximate and ultimate determinants of avian brood reduction. In: Parmigiani S, Saal F vom (eds) Infanticide and parental care. Harwood Academic Publ., USA pp 237–256
Garnett MC (1981) Body size, its heritability and influence on juvenile survival among great tits, Parus major. Ibis 123: 31–41
Gibbons DW (1987) Hatching asynchrony reduces parental investment in the jackdaw. J Anim Ecol 56: 403–414
Haftorn S (1981) Incubation during the egg-laying period in relation to clutch size and other aspects of reproduction in the great tit Parus major. Ornis Scand 12: 169–185
Harper RG, Juliano SA, Thompson CF (1992) Hatching asynchrony in the house wren, Troglodytes aedon: a test of the broodreduction hypothesis. Behav Ecol 3: 76–83
Haydock J, Ligon JD (1986) Brood reduction in the Chihuahuan raven: an experimental study. Ecology 67: 1194–1205
Henny CJ (1972) An analysis of the population dynamics of selected avian species. US Fish Wildl Serv Wildl Res Rep 1
Hochachka W (1990) Seasonal decline in reproductive performance of song sparrows. Ecology 71: 1279–1288
Hogstedt D (1980) Evolution of clutch size in birds: adaptive variation in relation to territory quality. Science 210: 1148–1150
Howe HF (1976) Initial investment, clutch size, and brood reduction in the common grackle (Quiscalus quiscula). Ecology 59: 1109–1122
Husby M (1986) On the adaptive value of brood reduction in birds: experiments with the magpie Pica pica. J Anim Ecol 55: 75–83
Hussell DJT (1972) Factors affecting clutch size in arctic passerines. Ecol Monogr 42: 317–364
Krementz DG, Nichols JD, Hines J (1989) Postfledging survival of European starlings. Ecology 70: 646–655
Lack D (1947) The significance of clutch size. Ibis 89: 302–352
Lack D (1954) The natural regulation of animal numbers. Clarendon, Oxford
Magrath RD (1989) Hatching asynchrony and reproductive success in the blackbird. Nature 339: 536–538
Magrath RD (1990) Hatching asynchrony in altricial birds. Biol Rev 65: 587–622
Magrath RD (1991) Nestling weight and juvenile survival in the blackbird, Turdus merula. J Anim Ecol 60: 335–351
Meyburg BU (1974) Sibling aggression and mortality among nestling eagles. Ibis 116: 224–228
Mock DW (1984) Infanticide, siblicide, and avian nestling mortality. In: Hausfater G, Hrdy SB (eds) Infanticide: comparative and evolutionary perspectives. Aldine, New York, pp 3–30
Mock DW (1985) Siblicidal brood reduction: the prey size hypothesis. Am Nat 125: 327–343
Mock DW, Parker GA (1986) Advantages and disadvantages of egret and heron brood reduction. Evolution 40: 459–470
Nilsson JA, Smith HG (1988) Effects of dispersal date on winter flock establishement and social dominance in marsh tits Parus palustris. J Anim Ecol 57: 917–928
Nisbet ITC, Drury WH (1972) Post fledging survival in herring gulls in relation to brood size and date of hatching. Bird Banding 43: 161–172
Nur N (1984) The consequences of brood size for breeding blue tits. II nestling weight, offspring survival, and optimal brood size. J Anim Ecol 53: 497–517
O'Connor RJ (1978) Brood reduction in birds: selection for fratricide, infanticide and suicide? Anim Behav 26: 79–96
Parker GA, Mock DW, Lamey TC (1989) How selfish should stronger sibs be? Am Nat 133: 846–868
Perrins CM (1965) Population fluctuations and clutch size in the great tit Parus major. J Anim Ecol 34: 601–647
Pijanowski BC (1992) A revision of Lack's brood reduction hypothesis. Am Nat 139: 1270–1292
Ricklefs RE (1965) Brood reduction in the curve-billed thrasher. Condor 67: 505–510
Ricklefs RE (1967) A graphical method of fitting equations to growth curves. Ecology 48: 977–983
Shaw P (1985) Brood reduction in the blue-eyed shag Phalacrocorax atriceps. Ibis 127: 476–494
Slagsvold T (1982) Clutch size, nest size, and hatching asynchrony in birds: experiments with the fieldfare (Turdus pilaris). Ecology 63: 1389–1399
Slagsvold T (1986) Asychronous versus synchronous hatching in birds: experiments with the pied flycatcher. J Anim Ecol 55: 1115–1134
Slagsvold T (1989) Experiments on clutch size and nest size in passerine birds. Oecologia 80: 297–302
Slagsvold T, Sandvik J, Rofstad G, Lorentsen O, Husby M (1984) On the adaptive value of intraclutch egg-size variation in birds. Ornis Scand 17: 117–225
Skagen SK (1988) Asynchronous hatching and food limitation: a test of Lack's hypothesis. Auk 105: 78–88
Stouffer PC, Power HW (1990) Density effects on asynchronous hatching and brood reduction in European starlings. Auk 107: 359–366
Trivers RL, Willard DE (1973) Natural selection of parental ability to vary the sex ratio of offspring. Science 179: 90–92
Wiebe KL (1993) Facultative manipulation of hatching asynchrony in American kestrels (Falco sparverius). Ph.D. Thesis, University of Saskatoon, Saskatchewan Canada.
Wiebe KL, Bortolotti GR (1992) Facultative sex ratio manipulation in American kestrels. Behav Ecol Sociobiol 30: 379–386
Wiebe KL, Bortolotti GR (1993) Brood patches of American kestrels: an ecological and evolutionary perspective. Ornis Scand 24: 197–214
Wiebe KL, Bortolotti GR (1994a) The role of food in determining hatching spans of birds: energetic constraints or facultative manipulation? Ecology 75: 813–823
Wiebe KL, Bortolotti GR (1994b) Energetic efficiency of reproduction: the benefits of asynchronous hatching for American kestrels. J Anim Ecol 63: 551–560
Zach R (1982) Hatching asynchrony, egg size, growth, and fledging in tree swallows. Auk 99: 695–700
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wiebe, K.L., Bortolotti, G.R. Food-dependent benefits of hatching asynchrony in American kestrels Falco sparverius . Behav Ecol Sociobiol 36, 49–57 (1995). https://doi.org/10.1007/BF00175728
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00175728