The seminar I attended was The Evolutionary Ecology of Plastic Traits in Birds” by David C. Lahti Wednesday, April 08, 2009. He used two birds to answer the question of how a learned trait can evolve. The birds under examination were the weaver bird and swamp sparrows. In the case of the village weaver bird, he wanted to know how they were able to cope with cuckoos laying eggs in the weaver’s nests. The males are very skilled weavers and make nests then display underneath them. The females find this attractive and choose a nest then push away the males. From afar, a large tree of male weavers displaying resembles a tree on fire. The cuckoos would find a nest and lay an egg while pushing another egg out. The maturity rate for cuckoos is higher than that of the weaver so the young cuckoos would hatch before the others often and push out the not hatched eggs or even hatched weaver young. The experiment done was to test how the weavers have coped with this. The females have a large variety of eggs within the population, but very similar within each clutch. He
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