The Boyce and Perrins model and the Lack model are two of the most commonly used models for explaining optimal clutch size. Both models share the same goal of finding the best clutch size that will maximize the offspring’s survival rate. However, there are some important differences between the two models. In this article, we will look at how the Boyce and Perrins model and the Lack model are different in their approach to predicting optimal clutch size.

The Boyce and Perrins Model

The Boyce and Perrins model, developed by two British ornithologists in the late 1970s, suggests that average clutch size should be the maximum possible clutch size in good years. The model assumes that, in good years, when food is abundant, birds should take advantage of the opportunity and produce as many offspring as possible. During bad years, the model suggests that birds will select the smallest clutch size that is predicted to give the highest chance of survival. This approach is based on the assumption that smaller clutches can survive the bad years better than larger ones.

The Lack Model

The Lack model, developed by British ornithologist David Lack in the mid 1940s, differs from the Boyce and Perrins model in its approach. Lack argued that birds should not always select the maximum clutch size. Instead, he suggested that birds should select an optimal clutch size that is smaller than the maximum, but larger than what would be predicted to maximize their offspring’s survival rate. This model is based on the idea that birds can benefit from having some eggs in reserve for future years when food is not as abundant. This approach has been supported by data showing that reproductive success increases with clutch size (Boyce and Perrins 1987).

Conclusion

In conclusion, the Boyce and Perrins model and the Lack model are two approaches to finding the best clutch size that will maximize the offspring’s survival rate. While both models achieve the same goal, they differ in their approach. The Boyce and Perrins model suggests that average clutch size should be the maximum possible clutch size in good years, while the Lack model suggests that birds should select an optimal clutch size that is smaller than the maximum but larger than what would be predicted to maximize their offspring’s survival rate.