Editing Predation (section)

===Assessment===

[[File:Ladybug aphids.JPG|thumb|[[Seven-spot ladybird]]s select plants of good quality for their [[aphid]] prey.]]

Having found prey, a predator must decide whether to pursue it or keep searching. The decision depends on the costs and benefits involved. A bird foraging for insects spends a lot of time searching but capturing and eating them is quick and easy, so the efficient strategy for the bird is to eat every palatable insect it finds. By contrast, a predator such as a lion or falcon finds its prey easily but capturing it requires a lot of effort. In that case, the predator is more selective.<ref name=Pianka/>

One of the factors to consider is size. Prey that is too small may not be worth the trouble for the amount of energy it provides. Too large, and it may be too difficult to capture. For example, a mantid captures prey with its forelegs and they are optimized for grabbing prey of a certain size. Mantids are reluctant to attack prey that is far from that size. There is a positive correlation between the size of a predator and its prey.<ref name=Pianka/>

A predator may assess a patch and decide whether to spend time searching for prey in it.<ref name=Kramer2001/> This may involve some knowledge of the preferences of the prey; for example, [[ladybird]]s can choose a patch of vegetation suitable for their [[aphid]] prey.<ref name="WilliamsFlaxman2012">{{cite journal |last1=Williams |first1=Amanda C. |last2=Flaxman |first2=Samuel M. |title=Can predators assess the quality of their prey's resource? |journal=Animal Behaviour |volume=83 |issue=4 |year=2012 |doi=10.1016/j.anbehav.2012.01.008 |pages=883–890 |s2cid=53172079}}</ref>