This model was constructed to test the influence of landscape-level features on migration strategies. The model was designed to test these hypotheses by including the effects of stopover spacing along the migratory corridor, latitudinal and temporal gradients, temperature, photoperiod, and energy reserves of the birds. By combining the model with field data sampled at stopover sites from Texas to the breeding grounds in Alaska, the authors were able to determine that female Pectoral Sandpipers, depending on conditions along the route, combine both strategies. If there is excess prey along the route, the females arrive with excess fat. This is modulated by the time of migration.
Females migrating later in the year minimize the length of migration.
Males, on the other hand, are essentially time-minimizing migrators. This strategy allows for males to arrive on the breeding grounds and claim a territory before the females arrive. The strategies utilized by both males and females maximize their respective abilities to reproduce. This paper uniquely integrated the idea of the landscape and its effect on migration with field data and natural history information known about the Pectoral Sandpiper. Lastly, in the Discussion, the authors address one reviewer s comments that the paper could have been written minus the modeling information, but the authors point out that field data do not stand alone and are better interpreted in the light of some concept, or model of the system being studied.