Tuesday, November 10, 2015

Winter Death of PearlMS

PearlMS, tagged by Dr. Jennifer Coulson in 2011 near the East Pearl River in Mississippi, spent most of the 2015 North American breeding season in his previous nesting neighborhood along the West Hobolochitto River near Picaynue, Mississippi. It is not always easy to determine whether a male is nesting, though on several occasions, data showed PearlMS roosting during the day in one particular location – a behavioral pattern that suggests incubation shifts.  Jennifer and her husband, Tom, searched the daytime roost locations, wading through the dark water and mud typical of this lowland forest habitat. They did not find a nest, “only lots of mosquitoes,” and concluded that 2015 was not a breeding year for PearlMS.

Southbound migration and last known location of PearlMS

PearlMS left his summer range on 12 August 2015, taking the western circum-Gulf route as opposed to the trans-Gulf route. At the end of the first day, he overnighted at a roost along the Atchafalaya River, then continued overland through Texas and Mexico, keeping within eyesight of the coast except when crossing the Texas/Mexico border, where he flew 80 miles inland around Reynosa.  On 22 August he passed near the famous River of Raptors migration station near Veracruz, Mexico, but was probably a little too far west to be among the counted!  He followed the contours of Central America and in mid-September reached the lush Pacific forests of the western Colombian Andes. PearlMS moved southwest along the range and slowed some, gaining energy required to traverse the high mountain peaks. Having crossed safely, he spent a few days along the Caqueta River in Colombia, then continued through northeastern Peru into the state of Amazonas, Brazil.  Here, where forested rivers provide ample food for migrating kites, PearlMS slowed again to take advantage of the abundant prey.  


On 13 October 2015, only days from reaching his wintering grounds in southern Rondônia, Brazil, PearlMS’s transmitter went quiet. Unfortunately, the most likely explanation is that he is dead. Dr. Coulson has engaged the help of local scientists, hoping they can access the location of the bird’s last signal to look for any evidence. His last transmission came from a remote area of mixed forest and pasture within a very large farm near a dam, the Saldanha Small Hydroelectric Project on the Saldanha River in the municipality of Alta Floresta D’Oeste in Rondônia, Brazil. Although the biologists have not yet gained access to the area, they intend to persist, hopeful they may find some useful clues.