nudicaudus) followed by mouse opossums (Marmosa ssp.) of unidentified species. Numerous bats, such as greater spear-nosed bats (Phyllostomus hastatus) and broad-eared bats (Nyctinomops laticaudatus), are also rather vulnerable apparently. Smaller monkeys such as tamarins (Saguinus ssp.) may be vulnerable to predation. Prey species can be heavier than the preying owl, weigh over , possibly up to in Didelphis opossums, Mephitis skunks and agoutis (Dasyprocta ssp.). Even the three-toed sloth (Bradypus variegatus) has been reported to have been killed, specifically an adult female estimated at in weight or more than four times the weight of the owl itself. Invertebrates are eaten regularly as well, second only in importance to mammals, and may be comprised mainly by caterpillars, but also crabs, snails, large insects, caterpillars and spiders. Insects may be gleaned directly from foliage while the large owls actively forage. Frogs are also recorded amongst their prey. Birds are also taken, including mainly medium-sized species in the average weight range of , such as jays, oropendolas (Psarocolius ssp.), motmots (Momota ssp.), and pigeons (Patagioenas ssp.), which are taken off of their nocturnal perches and perhaps smaller types of owl (e.g. Megascops ssp.). Little is known how spectacled owls interact with other owls but a study where playback of a number of owl species were played in Costa Rica, spectacled owls appeared to the least responsive, neither vocally stimulated by the calling of other owl species nor by playback of calls of their own species. Reproduction In Costa Rica, eggs are laid variously in the dry season (November–May), or at the start of the wet season (June–July). This owl typically nests in an unlined tree cavity but may also use the crutch of a large tree. Like all owls, they do not build a nest so just lay their nest on the bare surface of the wood given, usually rotting wood in the case of tree cavities. Spectacled owls lay 1-2 eggs, which are incubated entirely or almost so by the female for about 5 weeks. If two eggs are hatched, often only one of the chicks will survive, the smaller chick usually perishing via starvation or by aggression from the larger nestling. Chicks leave the nest for surrounding branches at about 5–6 weeks but cannot usually fly well at this stage. However, they tend to depend on their parents for several months after leaving the nest and may be cared for and