
I recently found out that the (error-plagued) Dyer & Howell guide to the Birds of Costa Rica states that the Tropical Mockingbird (Mimus gilvus) was first seen in Costa Rica in 2000. That is off by well over a century. However, its actual status is murky. eBird classifies the populations of Costa Rica and Panamá as being established exotics that escaped from caged birds in Panama. Specifically, Birds of the World states that:
It does not list a year that it was first seen in Costa Rica, however by 1989 when Stiles & Skuch published their guide to the birds of Costa Rica they stated that it was:
The 1989 field guide to the birds of Panama is a little more specific, registering the first sighting as in 1932 and stating that it was "apparently introduced from Colombia".
When Eisenmann compiled his list "The Species of Middle American Birds" in 1955 for the Linnean Society he listed its range as including "cent. Panama (common, introduced [?])...recorded from Costa Rica).
Here is the really interesting bit. The alleged introduction of this species to southern Central America occurred in 1932 in Panama...yet Ridgway noted in "Notes on Some Costa Rican Birds" in the Proceedings National Museum, Vol. XIV - No. 809 that an adult Tropical Mockingbird of the South American race melanopterus was collected by Jose C Zeledon on March 1, 1887 in Zarcero. There is no mention in his report of any suspicion its origin was as an escapee. However, Slud 1964 insisted that "That such a striking open-country species should not ever again have been reported makes it almost certain that this was an escaped cage bird. I believe the species should be removed even from the hypothetical list."
The Tropical Mockingbird is now widespread throughout Costa Rica but the exact provenance of the population is unknown. Given that the birds were first seen in the late 20th century again in the South Pacific it is likely from a group of escapees that established themselves in western Panama around 1980.
In the 1930s, however, an introduced population was discovered in central Panama. Tropical Mockingbird occupies open habitats with scattered shrubs and trees, and readily colonizes towns and gardens.
It does not list a year that it was first seen in Costa Rica, however by 1989 when Stiles & Skuch published their guide to the birds of Costa Rica they stated that it was:
recorded sporadically, especially in S Pacific lowlands but almost certainly as escaped cage birds (S Mexico to el Salvador, Lesser Antilles, South America; introduced and established in C Panama, but wild birds unlikely in Costa Rica
The 1989 field guide to the birds of Panama is a little more specific, registering the first sighting as in 1932 and stating that it was "apparently introduced from Colombia".
When Eisenmann compiled his list "The Species of Middle American Birds" in 1955 for the Linnean Society he listed its range as including "cent. Panama (common, introduced [?])...recorded from Costa Rica).
Here is the really interesting bit. The alleged introduction of this species to southern Central America occurred in 1932 in Panama...yet Ridgway noted in "Notes on Some Costa Rican Birds" in the Proceedings National Museum, Vol. XIV - No. 809 that an adult Tropical Mockingbird of the South American race melanopterus was collected by Jose C Zeledon on March 1, 1887 in Zarcero. There is no mention in his report of any suspicion its origin was as an escapee. However, Slud 1964 insisted that "That such a striking open-country species should not ever again have been reported makes it almost certain that this was an escaped cage bird. I believe the species should be removed even from the hypothetical list."
The Tropical Mockingbird is now widespread throughout Costa Rica but the exact provenance of the population is unknown. Given that the birds were first seen in the late 20th century again in the South Pacific it is likely from a group of escapees that established themselves in western Panama around 1980.