Chapter 31, Problem 43A

Summary Introduction

To write:

Oystercatchers do not forage for the largest, most energy-rich mussels.

Introduction:

The large mussels provide many more calories than smaller mussels. The larger the mussel, the more it tends to be encrusted with the barnacles that make it harder to open.

Optimal foraging theory (OFT) is a behavioral study that helps in predicting the animal behavior while searching for food.

Oystercatchers are one of the few birds capable of opening oysters. A group of oystercatchers are known as a parcel of oystercatchers.

Explanation of Solution

Oystercatchers feeding on the edible mussel is analyzed and compared with an optimal diet model. It is found that the oystercatchers usually select mussels between 30 and 45 mm long. It should not be overgrown or thin shelled. Waste handling events and estimating the prey population is a good agreement. These results are further discussed in the optimal foraging theory (OFT).

The prey size classes are selected by their profit giving abilities, larger size classes are more profitable than smaller size classes.

The mussels should not be overgrown or thin shelled.

Conclusion

Oystercatchers do waste time inspecting prey that are subsequently not consumed.  The optimal size selection is calculated to determine the size selection that maximises energy intake rate.