A Tropical Mockingbird (Mimus gilvus) was discovered mid-April of 2012 near the entrance to the much-birded Sabine Woods coastal woodlot on the Upper Texas Coast, just some ~7 or so miles from the Texas/Louisiana border. It was seen by hundreds of people during the 3+ months that it was around (last detected at the end of July 2012). By sometime around mid-June 2012 the bird in question (presumed to be a female) was nesting with a Northern Mockingbird and they successfully fledged 2 or 3 young birds. The hybrid offspring were seen into early fall and then nothing (probably due to lack of birder coverage/interest) until the following spring (2013), when a couple of the presumed offspring were again seen around Sabine Woods when birder activity picked up again. The adult Tropical Mockingbird has never been relocated (as of November 2013).The wear and tear on the bird when it was initially found showed some worn tail feathers though nothing that would necessarily indicate that it had been caged recently. One keen observer noted that the back toe nail on the bird's right foot was missing and indeed you can see this on every photo from the beginning of the observation period. The bird in question didn’t exhibit any behaviors that would necessarily seem to indicate a captive origin.Tropical Mockingbirds are found as close to the Texas coast as se. Mexico, including the Yucatan peninsula and areas south & near to Veracruz. They are not known to be highly migratory. It is a gifted singer and it is also known to be a common cage bird, both within and outside its known natural range.
As the mockingbird's identification was never in question, the TBRC’s decision to accept or not accept this record for the state list came down to considering whether or not the bird’s occurrence was the result of natural vagrancy or the result of some human assistance. Material collected for this record included not only photos and documentation of the Sabine Woods bird and the hybrid offspring, but outside commentary from long-time birders in Mexico and central America discussing their experiences with Tropical Mockingbirds and how prone (or not) they seem to be for vagrancy or long-distance migration as well as any evidence of recent expansion . Other material that was considered included a recent record (2012) of a Tropical Mockingbird found in Spain, reports from the US Customs/Border Patrol regarding different species of birds recovered from attempted smuggling into the US, and even a webpage that showed a pet shop having Tropical Mockingbird(s) for sale. A recent paper concerning altitudinal movements of the species in Ecuador was also considered as were recent years of North American Birds where notable Tropical Mockingbird records/sightings have been documented on a couple occasions in Mexico and in nearby Central America. Another point that was considered was the possibility of a ship-assisted occurrence, with the Sabine River & Port of Beaumont being less than 10 miles away; the port of Houston/Galveston is only ~50 miles west and the port of New Orleans is some ~220 miles east of Sabine Woods.
With all the material considered, the committee voted 3-6 to NOT accept the record/species for the state list based on the question of provenance/natural occurrence. Clearly nobody on the committee claims to know for sure how the Tropical Mockingbird arrived on the Texas coast, but the majority opinion was that its natural occurrence was questionable. The committee acknowledges that this is our collective decision as there was no definite proof of provenance and we recognize that others may come to different conclusions. Documentation for other Tropical Mockingbird sightings is always welcome as a means of better establishing either a pattern of natural vagrancy or human assisted occurrences.
Secretary, Texas Bird Records Committee, November 2013