Question

An ecological problem is faced by the shorebird, the Black Oystercatchers (Haematopus bachmani), trying to open and feast on clams and mussels. Optimal foraging models predict that these birds should choose the largest, juiciest bivalves that they encounter. However, oystercatchers do not always choose the largest mussel or clam, often leaving them untouched. Why leave the biggest (containing the most energy) items? What is a possible explanation. How would you test your hypothesis?|

why do some animals end up choosing a not so quality animal over a smaller animal or animal that is more tasty but difficult to catch.   in this case the example is given of why this animal chooses the smaller animal? how can u test this hypothesis