College level ecology question about predators ? I want to investigate the rate
ID: 3007813 • Letter: C
Question
College level ecology question about predators ?
I want to investigate the rate at which snakes and other predators are attracted to and eat the eggs of two different species of birds. I remove eggs from original nests of the two species and place them in artificial nests. I then count the number of eggs eaten over time and compare the numbers. I find that 66% of the eggs of species A are eaten while only 12% of the eggs of species B are eaten. I therefore conclude that species A eggs are more attractive to predators. What is the experimental advantage of using artificial nests instead of real nests? What assumption is made here about real and artificial nests with regards to predation? If this assumption is false, how could my results be biased? Would this invalidate my conclusion? I repeat the experiment, but now I compare species A eggs with species C eggs. I again use artificial nests for species A eggs, but I remove and then replace the species C eggs in the original nests (which are the same size and shape as the artificial nests and are found at the same heights). I find that 63% of species A eggs are eaten while only 25% of species C eggs are eaten. I therefore conclude that species A eggs are more attractive to predators. Why would I need to remove and the replace the species C eggs back into their nests? What assumption is made here about real and artificial nests with regards to predation? If this assumption is false, how could my results be biased? Would this invalidate my conclusion?Explanation / Answer
a> Artificial birds nests help in studying birds whose nests are not that easy to find , like many of the tropical species.
b> here the assumption is made that the predation on artificial nests accurately estimates predation on real nests.
And that the predators prefer species A eggs than those of species B.
c> there might be other factors that come into play.So we cannot say that our assumptions are correct and our conclusion would
hold invalid.
d> during the first expreiment both species A and B eggs were placed in artificial nests and yes the predators accoding to us
likes species A eggs more. OS just to make sure that the predators found the both the artificial nests as real as the real nests.
and to consolidate on the fact that they liked species A eggs more we placed eggs of species C in real nests.
e>here the assumption is made that the predation on artificial nests accurately estimates predation on real nests.
And that the predators prefer species A eggs than those of species C.
f> our results are biased as in case 2 we placed species C eggs in real neast and kept the artificial nest for species A eggs and even then predators preferred eggs A so it shows that eggs A were not at any undue advantage.
This would not invalidate our conclusion as in all we experimented with 3 species eggs and in both the cases the predators choose species A eggs so so this is proof enough that our results are not invalid.