Table 1.

Summary of results from experiments in which foraging reward rate was manipulated (without altering the predictability) in a closed economy system

Reward rateForaging activityMassNon-foraging activityBMR or RMRDaily food intakeDEE
StarlingVariable+00
Sturnus vulgaris 1
StarlingVariable+++
Sturnus vulgaris 2
Zebra finchVariable+00*0*
Taeniopygia guttata 3
Zebra finchVariable+00
Taeniopygia guttata (this study)
StarlingFixed+
Sturnus vulgaris 1
StarlingFixed+
Sturnus vulgaris 4
Zebra finchFixed+(−)
Taeniopygia guttata 5
Steely-vented hummingbirdFixed+**
Amazilia saucerottei 6
Fork-tailed emeraldFixed+**
Chlorostilbon canivetii 6
Domestic pigeonFixed+***
Columba livia 7
House mouseFixed00
Mus domesticus 8
Deer mouseFixed00
Peromyscus maniculatus 8
Siberian hamsterFixed+
Phodopus sungorus 9
  • The responses to a decrease in foraging reward rate are shown. Reward rates could either be fixed (without variation) or variable (only mean fixed). +, increases; −, decreases; 0, no change; indicators in parentheses refer to trends (P<0.1).

    *But note the quantitative agreement with our result of a negative effect in Fig. 2; **perching MR (not directly measured); ***inferred from body temperature.

    1Fotheringham (1998), 2Wiersma et al. (2005), 3Lemon and Barth (1992), 4Bautista et al. (1998), 5Deerenberg et al. (1998), 6Tiebout (1991), 7Rashotte and Henderson (1988), 8Perrigo (1987), 9Day and Bartness (2001).