FAMILY MOMOTIDAE 451 



upward from a horizontal line as it proceeded. I was disappointed 

 not to find eggs. As motmots do not line the nest cavity it is 

 probable that the burrow had been used earlier by some other hole- 

 nesting bird as at the end there was a pad of fine rootlets, mixed 

 with a little moss, irregular in outline, about 15 centimeters in diameter 

 and 15 to 25 millimeters thick. 



Skutch, in a study of this subspecies in Costa Rica (Ibis, 1964, 

 pp. 321-332) found that the birds live in pairs for most of the year. 

 Birds engaged in what appeared to be courtship displays carried green 

 leaves or bits of twig in the bill, though such materials were not 

 taken into their nests. Excavation of the nest burrows began in the 

 wet season from August to October, and continued for more than 



2 months, though the burrow when completed was not used for 

 sleeping quarters, and was seldom visited until the following March 

 or April when 3 white eggs were laid in the unlined nest chamber. 

 Incubation was shared by male and female, the period being about 



3 weeks. Young are naked when hatched. Adults eat a variety of 

 insects, spiders, small lizards, and fruits of various kinds. The young 

 are fed insects, including caterpillars. These motmots are reported 

 to capture birds occasionally, and once Skutch saw parents bring 

 a small bird, apparently adult, but not identified. The nest burrow 

 may be used for more than one season, sometimes alternately with 

 other hole-nesting birds. 



The race lessonii, described by Rene-Primavere Lesson, with the 

 type locality Realejo in Nicaragua, was named in honor of his brother 

 Dr. Adolphe Lesson. The population of western Panama differs from 

 that of farther north in slightly larger bill, and also in somewhat 

 greener colors. With the series now available the average larger 

 bill size is apparent, but with much overlap in range from small 

 to large. On present information the difference does not warrant 

 separation of another form. The following measurements of a 

 series from Nicaragua and Costa Rica are included for comparison 

 with those from Panama given above : 



Males (15), 129.7-144.9 (136.3), tail 215.0-245.0 (229.9), cul- 

 men from base 38.0-45.7 (41.8), tarsus 27.0-31.0 (29.0) mm. 



Females (6), wing 127.6-140.8 (135.2), tail 217-245 (230.8), oil- 

 men from base 39.8-43.0 (41.4), tarsus 26.8-29.0 (27.9) mm. 



The subspecies lessonii ranges north through Central America to 

 southern Mexico. (For discussion of the Mexican population see 

 Wetmore, Proc. U. S. Nat. Mus., vol. 93, 1943, p. 268.) 



