Optimal Meal Size in Hummingbirds

Optimization theory is applied to hummingbird foraging to explain the observation that birds in the laboratory with access to functionally unlimited food supplies usually do not take as large a meal as they could. Foraging bouts are modeled in terms of time and energy; birds are constrained by the increased energetic costs associated with the added weight of their meal. Predictions of optimal meal size which maximize the rate of net energy gain or which maximize efficiency agree closely with laboratory and limited field data; we presently are unable to discriminate between these two optimality criteria. Predictions which assume optimal use of time or which maximize net energy gain or which neglect weight of the meal all proved unsatisfactory, generally by predicting optimal meal sizes in excess of capacity. Sensitivity analysis revealed that model predictions may be much influenced by parameter values potentially under physiological and/or behavioral control by a hummingbird. While we presently do not understand what governs the values of these parameters, we suggest that this control will eventually prove explicable by an optimality model of bird behavior.

[1]  P. Katz.  A Long-Term Approach to Foraging Optimization , 1974, The American Naturalist.

[2]  S. W. Roberts,et al.  Calculating the Nocturnal Energy Expenditure of an Incubating Anna's Hummingbird , 1974 .

[3]  P. Slater.  The temporal pattern of feeding in the zebra finch , 1974 .

[4]  F. Toates,et al.  Control of food intake by energy supply , 1974, Nature.

[5]  L. L. Wolf,et al.  Time and Energy Budgets of Territorial Hummingbirds , 1971 .

[6]  H P Zeigler,et al.  Patterns of feeding behavior in the pigeon. , 1971, Journal of comparative and physiological psychology.

[7]  D. M. Ware,et al.  Growth, Metabolism, and Optimal Swimming Speed of a Pelagic Fish , 1975 .

[8]  C. Herreid,et al.  Thermal conductance in birds and mammals. , 1967, Comparative biochemistry and physiology.

[9]  L. L. Wolf,et al.  Wing Disc Loading: Implications and Importance for Hummingbird Energetics , 1975, The American Naturalist.

[10]  I. Duncan,et al.  The pattern of food intake in female Brown Leghorn fowls as recorded in a Skinner box , 1970 .

[11]  L. L. Wolf,et al.  Energetics of Foraging: Rate and Efficiency of Nectar Extraction by Hummingbirds , 1972, Science.

[12]  F. Hainsworth.  Foraging Efficiency and Parental Care in Colibri coruscans , 1977 .

[13]  T. Casey,et al.  Power Output and Wing Disc Loading in Hovering Hummingbirds , 1973, The American Naturalist.

[14]  R. C. Lasiewski.  Oxygen Consumption of Torpid, Resting, Active, and Flying Hummingbirds , 1963, Physiological Zoology.

[15]  D. J. Hall,et al.  Optimal Foraging and the Size Selection of Prey by the Bluegill Sunfish (Lepomis Macrochirus) , 1974 .

[16]  E. Charnov.  Optimal Foraging: Attack Strategy of a Mantid , 1976, The American Naturalist.

[17]  F. Hainsworth,et al.  Crop volume, nectar concentration and hummingbird energetics. , 1972, Comparative biochemistry and physiology. A, Comparative physiology.

[18]  E. Stricker,et al.  The physiological psychology of hunger: a physiological perspective. , 1976, Psychological review.

[19]  L. Real.  A general analysis of resource allocation by competing individuals. , 1975, Theoretical population biology.

[20]  F. Gill,et al.  Foraging Efficiencies and Time Budgets in Nectar‐Feeding Birds , 1975 .

[21]  F.Reed Hainsworth.  On the tongue of a hummingbird: its role in the rate and energetics of feeding. , 1973, Comparative biochemistry and physiology. A, Comparative physiology.

[22]  T. Schoener.  Theory of Feeding Strategies , 1971 .

[23]  C. S. Holling.  The functional response of invertebrate predators to prey density , 1966 .

[24]  S. C. Kendeigh,et al.  Environmental regulation of food intake by birds , 1969 .