Howler Monkey species ONLY in Izabal; not in Peten
The rare Mantled Howler Monkey, Alouatta palliata, is not in Peten nor Alta Verapaz. The “rust colored back” Mantled Howler Monkey, Alouatta palliata, is in the Municipio de Livingston, Izabal, Guatemala. More are on the east side of the Rio Motagua (towards Honduras, where Alouatta palliata it occurs from Honduras through the rest of Central America, and through South America to northern Peru).
Alouatta palliata is also in Veracruz, Chiapas, and Tabasco, Mexico. But no longer in adjacent Peten. Wikipedia is totally incorrect in a copy-and-paste error claiming Alouatta palliata is in Chiquimula, Guatemala. No, sorry, only in two areas of Izabal: along one segment of Rio Dulce and east of Rio Motagua.
We will work to find, photograph, and publish flora and fauna of the Caribbean area of Guatemala, the Livingston area, from July or August onward (as soon flights from USA are allowed back into Guatemala, hopefully in July).
The popular Alouatta pigra, known as the Guatemalan black howler monkey, is easy to see, and hear, at Tikal and especially at Yaxha. This Guatemalan black howler can also be seen and heard at Las Guacamayas biological research station, Rio San Pedro (Peten). This howling monkey is also present in northern Alta Verapaz and well known for forested areas of Izabal (so there are two species in Izabal; but one in Peten and Alta Verapaz).