Charles and Mary Brown Have Demonstrated That as Cliff Swallow

Essay

Charles and Mary Brown have demonstrated that as cliff swallow colony size increases, the number of nests with one or more unhatched eggs decreases. They have also demonstrated that as the size of colony increases, the number of parasites increases, and these parasites cause nest failures and juvenile mortality. These two observations indicate that there are trade-offs in group living. What would be a better measure than unhatched eggs to understand the benefits of group living in cliff swallows?