has a large, blackish beak and dark grey feet. Lear's macaw is similar to the larger hyacinth macaw and the slightly smaller glaucous macaw. The hyacinth macaw can be distinguished by its darker plumage, lack of greenish tinge, and a differently shaped patch of yellow skin adjacent to the base of the bill. The glaucous macaw is paler and has a more greyish head. Ecology and behaviour Feeding The primary diet of Lear's macaw are the nuts (as many as 350 per day) of the palm Syagrus coronata, locally known as licuri, but the seeds of Melanoxylon, Jatropha mollissima, Dioclea, Spondias tuberosa, Schinopsis brasiliensis and Zea mays are also eaten, as well as the flowers of Agave. The macaw usually forages in groups. They preferentially feed on the palms where they grow in groves, mixed together with taller trees. At least thirty confirmed feeding localities are known throughout the range. A tall tree is selected by the flock as base to carefully inspect the feeding area. First a pair descends to the level of the palms to assess the suitability, the pair then returns to base, and then the entire flock descends to decide if it is worth staying around. If it is, then the macaws generally feed directly at the site, tearing the fibrous pulp off the fruit to obtain the extremely hard and thick-shelled nut. The pulp is discarded. The heavy bills appear to have evolved specifically to crack open the palm nuts with a chisel-shaped edge, being precisely of the correct size and shape. Upon occasion the birds maw fly off to a better perch to consume the nut, sometimes even carrying a branchlet with a few fruit. Such perches are generally a branch of a tall tree or a cliff face, and the ground below such a perch will become littered with piles of cracked palm nut shells, and are thus easily spotted. A mystery regarding plants in the Neotropics with very large fruit or seeds is which type of animal disperses the seeds, elsewhere on earth large herbivorous mammals are the dispersal agents for such plants, but these are largely absent in South America today. The prevailing theory is that such mammals once performed these functions, but that Late Pleistocene extinctions of most of these animals had rendered large-fruited plants impotent regarding the spread of their seed, at least until humans introduced livestock. The Syagrus