For the fourth consecutive breeding season, The Center for Conservation Biology is collaborating with CECARA, Center for the Study and Conservation of Birds of Prey of Argentina (Centro para el Estudio y Conservación de las Aves Rapaces en Argentina), to investigate post-fledging dependency, dispersal and survival in the crowned solitary eagle. The collaborative study tracks birds using satellite transmitters to investigate the early life of crowned eagles and to quantify movement and survival. Since 2012, 12 transmitters have been deployed on nestlings with a goal of eventually tracking 20 eagles. Alarmingly, none of the tracked birds have survived to breeding age (assumed to be 3 years). Three birds have been shot, three have been electrocuted, one drowned in a stock tank, and one died of unknown causes. The remaining 4 birds are between 1 and 2 years old. Early results suggest that juvenile survival may be contributing to population declines.
Joaquín Cereghetti approaches a nest and is greeted by a nestling crowned eagle in the top of a Eucalyptus tree. Photo by Bryan Watts.
The crowned eagle is both one of the most critically endangered raptors in the world and one of the most charismatic species in South America. The species occurs in arid regions of Argentina, Paraguay, southern Brazil and southern Bolivia. The crowned eagle has an extremely low reproductive rate, producing 1 young each year (or possibly every other year), and feeds primarily on snakes and armadillos. In the arid La Pampa region of Argentina, crowned eagles are nearly restricted to the declining Caldén forest and associated grasslands.
Dr. Jose Sarasola (left) holds a nestling crowned eagle with PhD. student Maxi Galmes (right). Photo by Bart Paxton.
Fieldwork during the 2014-2015 breeding season is being conducted by Dr. Jose Sarasola (Director of CECARA) and Joaquín Cereghetti. In addition to deploying transmitters, the team is monitoring nest occupancy and breeding success.
Primary habitat of the crowned eagle, the native Caldén forest has declined over the past several decades throughout its historic range in South America. Photo by Bryan Watts.
Written by Bryan Watts | bdwatt@wm.edu | (757) 221-2247
January 12, 2015
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Another crowned eagle shot
A bald eagle nest just off the Poropotank River in Virginia in 2003. A nest with two equal young and ample food was a normal scene during this time period. This reflects a golden period during the late 1990s and early 2000s when males had more leisure time to hunt and provide for broods. Photo by Catherine Markham.
Breeding female on the Eltham Bridge. This female was hatched on Elkins Marsh along the seaside of the Delmarva in 2010 and has held the territory on the Eltham Bridge since 2013 with three successive males. She has been very aggressive and protective of the nest site and has held the territory together. She was found with a wing injury from a collision in December and could not be rehabilitated. She is one of a number of falcons that have been documented to go down in 2022. Photo by Bryan Watts.