A RECORD OF “DILUTION” PLUMAGE ABERRATION IN THE RUFESCENT TIGER-HERON (TIGRISOMA LINEATUM)

Abstract

Plumage aberrations are common in wild birds; however, there are few documented records for most Neotropical bird species. Here, we present the first documented record of dilution plumage aberration in Rufescent Tiger-Heron (Tigrisoma lineatum). In August 2017, we observed an individual of Rufescent Tiger-Heron with a “diluted” plumage coloration compared to the typical coloration for this species. With yellowish-brown feathers in head and neck, and especially a pale gray coloration in upperparts, the overall appearance seems to be, most likely, a case of “Pastel” dilution aberration. However, the pale gray tones may have been caused by the light conditions during obser- vation which make it difficult to determine the dilution type with certainty. The documentation of these cases can be a valuable source of information to understand chromatic aberrations and variations between different groups of birds.