Specimens (7): [Female], 40589, 367.3 gm. (July 12), [Male], 40588, testis 8 × 3 mm., 414.5 gm. (July 14), [Female], 40590, ovary 11 mm., 347.4 gm. (July 15), [Male], 40591, testis 5 × 3 mm., 371 gm. (July 15), [Male], 40593, testis 6 × 3 mm., 422.2 gm. (July 16) and [Male], 40592, 401.5 gm. (July 16), 6-7-1/2 km. W Escárcega; [Female], 40587, 395.5 gm. (July 28), Pueblo Nuevo X-can. _Piculus rubiginosus yucatanensis_ (Cabot): Red-capped Green Woodpecker.--Specimen (1): [Female], 40594, ovary inactive (7 × 4 mm.), extensive body molt, 67.7 gm. (August 17), 4 km. NNE Felipe Carrillo Puerto. Mallophaga: _Penerirmus_ sp. _Drycopus lineatus similis_ (Lesson): Lineated Woodpecker.--Specimen (1): [Male], 40595, molting, 141.2 gm. (July 15), 7-1/2 km. W Escárcega. _Centurus aurifrons dubius_ (Cabot): Golden-fronted Woodpecker.--The gonads were moderately enlarged in several of the specimens taken in the first half of July. The plumage was much worn in all specimens and some were in early stages of molt. Apparently the breeding season on the peninsula extends to at least mid-July. The specimen from Isla Cozumel is assigned to _C. a. dubius_, following the systematic treatment by Selander and Giller (1963). Specimens (10): sex? 40602, 75.0 gm. (July 8), and [Female], 40601, ovary 6 × 3 mm. (enlarged oviduct), 76.4 gm. (July 10), 1 km. S Puerto Real, Isla del Carmen; [Male], 40599, testis 6 × 8 mm., 101.3 gm. (July 10), and [Male], 40600, 86.0 gm. (July 11), 5 km. S Champotón; [Male], 40603, testis 5 × 3 mm. (July 14), and [Female], 40604, ovary 6 × 4 mm. (ova to 1 mm.), brood patch (July 16), 7-1/2 km. W Escárcega; sex? 40596, molting, much visceral fat, 79.0 gm. (July 22), Pisté; [Female], 40597, 73.7 gm. (July 28), Pueblo Nuevo X-can; [Female], 40598, 79.6 gm. (August 15), 4 km. NNE Felipe Carrillo Puerto; [Male], 40605, testis inactive, molting, much visceral fat (August 8), 3.5 km. N San Miguel, Isla Cozumel. _Centurus pygmaeus_ (Peters): Yucatán Woodpecker.--Paynter (1955a:166) reported evidence of breeding in this species on April 3 and May 23; a male having enlarged testes was taken on July 10. Specimens (5): [Male], 40608, testis 6 × 4 mm. (July 10); [Female], 40607, 39.5 gm. (July 10), 5 km. S Champotón; [Male], 40609, testis inactive, 35.8 gm., moderate visceral fat (July 17), 1 km. N, 13 km. W Escárcega; [Female], 40606, ovary 6 × 4 mm. (inactive), 37.0 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto; [Male], 40610, testis inactive, heavy visceral and subcutaneous fat, 41.6 gm., (August 10), 3-1/2 km. N San Miguel, Isla Cozumel.