caa a22 4500 46582174X CHVBK 20180323112137.0 cr unu---uuuuu 170327e19900301xx s 000 0 eng 10.1007/BF00047272 doi (NATIONALLICENCE)springer-10.1007/BF00047272 The value of fat reserves and the tradeoff between starvation and predation [Elektronische Daten] There's a special providence in the fall of a sparrow Hamlet Act V sc ii [John McNamara, Alasdair Houston] It is shown that in a range of models, the probability that a forager dies from starvation is, to a good approximation, an exponential function of energy reserves. Using a time and energy budget for a 19g passerine, we explore the consequences, in terms of starvation and predation, of various levels of energy reserves. It is shown that there exists an optimal level L of reserves at which total mortality (starvation plus predation) is minimized. L increases when the environment deteriorates as a result of a decrease in either temperature or mean gross gain or an increase in the mean search time. The effect of combined deteriorations is greater than the sum of their individual effects. At L, the probability of predation is much higher than the probability of starvation. A simple analytic model suggests that this result will be fairly general, but also indicates conditions under which the result might not hold. Kluwer Academic Publishers, 1990 McNamara John School of Mathematics, University Walk, BS8 1TW, Bristol aut Houston Alasdair Department of Zoology, EGI, South Park Road, OX1 3PS, Oxford aut Acta Biotheoretica Kluwer Academic Publishers 38/1(1990-03-01), 37-61 0001-5342 38:1<37 1990 38 10441 https://doi.org/10.1007/BF00047272 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00047272 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- McNamara John School of Mathematics, University Walk, BS8 1TW, Bristol aut NATIONALLICENCE 700 1- Houston Alasdair Department of Zoology, EGI, South Park Road, OX1 3PS, Oxford aut NATIONALLICENCE 773 0- Acta Biotheoretica Kluwer Academic Publishers 38/1(1990-03-01), 37-61 0001-5342 38:1<37 1990 38 10441 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer