Eumomota superciliosa superciliosa (Sandbach): Turquoise-browed Motmot.—On July 9 this species was nesting in a large "colony" 5 km. S Champotón, Campéche, in a large abandoned gravel pit having vertical banks about 10 feet high. The pit was an irregular semicircle with an approximate radius of 100 yards and was bordered by a road on one side and elsewhere by low scrub vegetation. The pit was one of several found in the area and formerly was used as a source of limestone gravel used in constructing the road between Champotón and Escárcega. The exposed limestone substratum was overlaid with chalky soil six to eight feet deep.
Motmots were nesting in burrows dug in the layer of surface soil. A total of 101 burrows seemed to be in use or to have been used in 1962. Nine appeared to be unused and 24 burrows evidently were abandoned before they were finished. The depths of 12 burrows selected at random were 34, 32, 37, 25, 28, 44, 36, 36, 24, 37, 22, and 43 inches, and averaged 33.4 inches. In cross-section the burrows varied from round (three inches in diameter) to oval (three inches high and four inches wide). The inner ends of the burrows were enlarged with a depression in the floor, where the eggs were laid.
The long axes of most burrows were straight and perpendicular to the face of the bank in which they were dug; two burrows nevertheless were curved laterally, and one was U-shaped, having two entrances that opened about 12 inches apart.
Eggs and nestlings were found lying on the bare soil at the inner ends of the burrows; no nesting material was found.
The contents of 10 burrows that were excavated are summarized in Table 1. Three nests contained no eggs or young. One of these was freshly dug. The other two empty burrows apparently had been recently occupied by nestlings and contained the foul smelling remains of fecal material, hundreds of beetle wings, and other undigestible parts of insects. The manure was teeming with large fly larvae.
Table 1. Contents of 10 burrows of Turquoise-browed Motmots.
| Burrow | Fresh | Eggs | Nestlings | Post-fledgling |
| 1 | * | |||
| 2 | 4 | |||
| 3 | 3 | |||
| 4 | 4 | |||
| 5 | 1 | 3 | ||
| 6 | 4 | |||
| 7 | 1 | |||
| 8 | x | |||
| 9 | * | |||
| 10 | * |
* Nothing.
x Broken egg shells.
Three burrows contained nestlings; one had four young with pin feathers, one a chick fully feathered, and one three newly hatched young and one egg.
In burrow 2, three eggs had advanced embryos and one was infertile; in burrow 3, the eggs had small embryos; and in burrow 4, the eggs appeared fresh. Burrows 3 and 4 were occupied by adult birds that did not flush during the excavation of their burrows. They were easily caught by hand and later prepared as specimens. One was a male and the other a female; each had a brood patch.