Question

Use the table to the right to answer the next 3 questions. Q2.24. Based on these data, what is the profitability of stoneflies? cal/s Submit Q2.25. Assume that early in the summer, the only prey available are stoneflies and caddisflies. If the search time for its preferred prey (the more profitable stonefly) is too long, the house martin should include both stoneflies and caddisflies in its diet. What is the value of this critical search time for stoneflies? (Hint: be careful to use values from the correct rows and columns of the table in your calculation!) S Submit Q2.26. Later in the season, stoneflies have disappeared and house martins must choose between caddisflies and mayflies. This means that the critical search time for the preferred (more profitable) prey is 2 seconds. Assuming birds forage optimally, which prey items should a house martin eat? Caddisflies only Mayflies only Both caddisflies and mayflies There is not enough information to answer the question. Submit

Answer 1

2.2.24, profitability = Energy content gained (Ei) Handling time his 0.9 profitability for Stoneflies = 3 0:3 Calls answer 22.25 The value of critical search time for the stone flies will be Search time for Caddie flies t search time for Stoneflig 88 an = 3t 5= Answer

Q. 2.262 Profitability of claddisflies is 0.4/2= 0.2 profitability of mayflies is 0.2/2 002/2 = o.1 of the search time is high for the more Profitable prey, then eat bothe species but, if the search time is small for the profitable Prey then eat only that profitable species. In the given Question, The search time for Caddisfries is high (35) "gf E2/he is greater than the Es/ (hatst) then eat both the prey species • If E2/h2 is less than Es/Chits) then eat more profitable prey. only the Therefor a house martin Should eat bothe species the Caddisfly and the may fly. The Correct answer is option (iii. Both caddisflies and may flies, Answer