Another ani egg

Yesterday we found another bird egg on the ground under the mumbaca palms. I assume they are from the greater ani (Crotophaga major) because they hang out in the palms, as well as neighboring trees. The question now is whether or not the nest belongs to them. My theory is that the anis are laying eggs in another bird's nest and the rightful owners are tossing the eggs out. This is the third egg we've found. The first was show in a previous post and the second one broke when it hit the ground. Cleuson, who spends the whole day at the Bosque, remarks that not once has he seen the anis bring in nesting material and not once has he seen them taking food to the young ones.