FAMILY FORMICARIIDAE 21 5 



Rica), wing 90.5-96.1 (93.3), tail 48.4-53.3 (51.9), culmen from 

 base 23.0-25.8 (24.4), tarsus 33.5-37.7 (34.8) mm. 



Females (7 from Chiriqui and western Costa Rica), wing 88.2- 

 93.1 (90.9), tail 47.1-53.1 (50.4), culmen from base 22.3-24.7 

 (23.4), tarsus 31.8-34.1 (32.8) mm. 



Resident. Rather rare; found locally in forested areas in western 

 Chiriqui, mainly in the tropical lowlands, but to 1460 meters on Cerro 

 Pando. 



The first report, by Salvin (Proc. Zool. Soc. London, 1870, p. 195), 

 was of one taken by Arce at Bugaba. Bangs (Auk, 1901, p. 366) 

 received a female secured by Brown at Divala, December 11, 1900. 

 In my own studies I collected a male and heard others calling in the 

 forest at 1250 meters above the Quebrada Guisado, near Santa Clara, 

 March 20, 1954. We have two taken by Dr. Frank Hartman near 

 El Volcan, February 27, 1949, and March 7, 1951. In my collections, 

 a female was taken February 16, 1960, at 1460 meters on Cerro 

 Pando, west of El Volcan, and a male was caught March 17, 1965, 

 in a mist net at a lower elevation, near Palo Santo. 



Through the observations of Alexander Skutch in southwestern 

 Costa Rica (Pac. Coast Avif., no. 35, 1969, pp. 275-289) the Hfe 

 history of this race is known in detail. As the birds walk over the 

 forest floor they flick leaves aside with the bill to expose insects hid- 

 ing underneath. These are seized instantly. They also come to raid- 

 ing ant swarms but remain on the ground outside the moving ants, 

 and pick up fleeing insects. Small lizards are eaten regularly, and 

 once Skutch saw one killing a tiny snake. He found the nests regu- 

 larly in the tubelike hollow centers of dead, or occasionally of living 

 trunks of slender palms or other trees, often at some distance below 

 the entrance hole. Dead leaves were used often in considerable 

 amount as a base for the nest. In this two eggs were laid, oval in 

 form and, when fresh, white with slight gloss. They quickly become 

 stained from the damp nesting material, or dirty from mud from 

 the feet of the incubating birds. Two eggs measured 33.9x24.8 and 

 33.4x24.8 mm. Both male and female incubate and care for the 

 young. These at hatching have dark gray down so long that it com- 

 pletely envelops them. At the corners of the mouth there are wide 

 white flanges that stand out prominently in the dark nest cavity. 

 Young at about 18 days of age are well feathered, but with the 

 developing contour feathers still much covered by the long down. 

 At this age they appear at the nest opening, fly down the short 

 distance, and then follow the parents as they walk on the ground. 



