The Baltimore Oriole is a colorful, migratory bird that can be seen all around the country during migration season. With such bright orange body and black head and wings, the male almost looks like a very poisonous beetle, but no bird species is poisonous to the extent of my knowledge. The female is duller, and does not have a black head as opposed to the male. The juvenile bird is even duller or pale when compared with both adults, though in low light it can be confused with the adult female.
This species comes from North America during late autumn and winter to escape the harsh, cold weather and find the abundance of the Costa Rican Tropical Rain Forest every year. I have seen it in various places, including Ciudad Colón, Río Frío, Sarapiquí and now Boca Tapada, where a lot of individuals were feasting on the fruit that the lodge administrator puts on the feeders. They can be seen fighting for the best feeding spots with Tanagers and Honeycreepers.
There are actually quite a few poisonous birds. Including the Pitohui which is related to the Oriole bird.