292 BIRDS OF THE REPUBLIC OF PANAMA PART 4 



Immatures, upper surface burly olive; undersurface yellow, tinged 

 brown on throat and upper breast. 



Measurements. — Males (10 from Panama), wing 58.9-65.0 (61.5), 

 tail 45.9-50.7 (48.6), culmen from base 10.2-12.7 (11.4), tarsus 17.8- 

 21.2 (19.8) mm. 



Females (8 from Panama), wing 55.4-60.1 (57.5), tail 45.5-51.7 

 (46.7), culmen from base 10.7-12.2 (11.4), tarsus 19.3-21.1 (20.4) 

 mm. 



Migrant and winter visitor from the north. Fairly common through- 

 out as a transient, less common as a winter resident. The Mourning 

 Warbler is found in Panama from mid-September to mid-May: F. S. 

 Blanton collected a male at Gamboa in the Canal Zone on September 

 16, 1953, and Monniche (Blake, Fieldiana: Zool., vol. 36, no. 5, 1958, 

 p. 559) collected a male at 1590 m on the Volcan de Chiriqui on May 

 16. E. A. Goldman's notes remark that this species was "rather com- 

 mon in the northern half of the Zone between January 11 and April 24 

 [1911] when the last one seen was shot at Gatun. The disappearance 

 of the migrating warblers and some other North American birds 

 seemed to be closely coincident with the opening of the rainy season 

 about April 24, as indicated by a thunder shower and change in the pre- 

 vailing direction of the wind. The wind about this time began to come 

 from southward or southwestward and the northerly trade ceased to 

 blow." Eisenmann saw 3 at Ft. Davis, Canal Zone, as late as May 11, 

 1960. 



I have encountered this species throughout the Republic, at El Vol- 

 can, Santa Clara, Concepcion, Buena Vista, and Alanje in Chiriqui; 

 Almirante, Bocas del Toro; El Valle and El Uracillo, Code; Chilar in 

 Colon; several localities in the Canal Zone and eastern Province of 

 Panama; on the Rio Jaque in Darien; and Mandinga and Puerto 

 Obaldia in San Bias. Ridgely (in litt.) finds that during the northern 

 winter it is numerous in the highlands of Chiriqui and Darien. It is 

 always in dense shrubbery or in an area of weeds bordering taller 

 growth. 



Banding studies indicate that Mourning Warblers wintering in Pan- 

 ama are faithful to a site through the winter and in succeeding years. 

 Loftin et al. (Bird-Banding, 1966, p. 42) had the following returns at 

 Almirante: April 19, 1963, retaken February 25, 1964; October 9, 1963, 

 retaken September 27, 1964; and November 1, 1963, retaken April 21, 

 1964. One banded at Gamboa January 27, 1964, was retaken there 

 November 11, 1964. Five collected by Burton (Bull. Brit. Orn. Club, 

 1975, p. 86) at El Real, Darien weighed from 9.5 to 10.0 g. G. V. N. 



