Part 10

Thryothorus lucovicianus albinucha (Cabot): Carolina Wren.--This wren formerly was considered to be a species (T. albinucha). In the light of evidence presented by Lowery and Berrett (1963), it is advisable to follow Paynter (1955a:219) and consider albinucha to be a subspecies of T. ludovicianus. The only previous evidence of breeding by this species on the peninsula was a male having slightly enlarged gonads taken by Paynter (1955a:219) on March 9.

Specimen (1): , 40754, juv., 16.8 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto.

Thryothorus maculipectus canobrunneus (Ridgway): Spotted-breasted Wren.--According to Paynter (1955a:220) this species breeds from mid-March to May 23. Gonads were moderately active in our specimens as early as mid-July.

Specimens (4): [Female], 40758, ovary (6 × 3 mm.) granular (July 14), and , 40757, testis 5 × 3 mm., 15.3 gm. (July 14), 7-1/2 km. W Escárcega; [Female], 40755, ovary 6 × 3 mm. (ova to 1 mm.), 12.7 gm. (July 21), Pisté; , 40756, ovary 4 × 3 mm., 16.8 gm. (August 3), 4 km. WSW Puerto Juarez.

Troglodytes musculus (Naumann): Southern House Wren.--Specimen (1): [Female], 40760, juv. (August 2), 4 km. WSW Puerto Juarez.

Troglodytes beani (Ridgway): Cozumel Wren.--Specimens (2): [Female], 40761, 13.3 gm. (August 9), and , 40762, imm., 13.6 gm. (August 9), 3-1/2 km. N San Miguel, Isla Cozumel.

Campylorhynchus yucatanicus (Hellmayr): Yucatán Wren.--This species was abundant in the coastal scrub west of Sisal where some breeding activity was noted. A few individuals were carrying nest material and several were feeding young. There were many old and abandoned nests and apparently the breeding season was nearly over. The only previous breeding record is for March 19 when a newly completed nest was found (Paynter, 1955a:218).

Specimens (4): , 40750, imm., 32.4 gm. (August 7), 1-1/2 mi. SW Sisal; [Female], 40751, imm., 31.2 gm. (August 18), 2 km. WSW Sisal; [Female], 40752, ovary 7 × 3 mm., 40 gm. (August 9), 4.3 km. WSW Sisal; [Female], 40753, 31.0 gm. (August 11), 6-1/2 km. WSW Sisal.

Melanoptila glabrirostris cozumelana (Paynter): Black Catbird.-- Apparently the only previous record of breeding by this species was Paynter's (1955b) mention of a male from Quintana Roo with enlarged gonads on June 26. The three adults in the collection here reported on were in nearly full reproductive activity.

Specimens (4): , 40764, imm., 40.5 gm. (August 8), [Female], 40767, testis 8 × 4 mm., 42.0 gm., heavy fat (August 8), [Female], 40765, ovary active (oviduct enlarged), brood patch, 35.2 gm. (August 10), and , 40766, testis 9 × 6 mm., 35 gm. (August 10), from 2-1/2-3-1/2 km. N San Miguel, Isla Cozumel.

Mimus gilvus (Vieillot): Tropical Mockingbird.--The only breeding record heretofore is by Paynter (1955a:226) of newly-fledged juveniles taken on May 26 and 29. Gonads in our adults were moderately active; feathers were extremely worn, but molting was not evident.

Specimens (4): , 40771, testis 9 × 6 mm., 51.0 gm. (July 9), 5 km. S Champotón; [Female], 40770, ovary moderately active (ova to 2 mm.), brood patch, 42 gm., moderate fat (August 9), 3-1/2 km. N San Miguel, Isla Cozumel; [Female], 40768, imm., 45.2 gm., moderate fat (August 18), 2 km. WSW Sisal; , 40769, testis 10 × 5 mm., 51.8 gm. (August 9), 13 km. WSW Sisal. Mallophaga: Myrsidea sp., July 9.

Toxostoma guttatum (Ridgway): Cozumel Thrasher.--Our specimen had enlarged testes and seems to represent the first record of breeding activity in the species.

Specimen (1): , 40772, testis 7 × 4 mm., 49.5 gm. (August 10), 3-1/2 km. N San Miguel, Isla Cozumel.

Turdus grayi Bonaparte: Clay-colored Robin.--Four adults were in full breeding condition.

Specimens (6): , 40780, testis 13 × 8 mm., brood patch (July 10), 5 km. S Champotón; [Female], 40781, ova to 8 mm., 79.6 gm. (July 15), 5 km. SW Escárcega; [Female], 40776, 61.3 gm. (July 21), Pisté; [Female], 40777, imm., 63.4 gm. (July 20), 6½ km. W Pisté; , 40779, testis 14 × 8 mm., brood patch, 68.5 gm. (July 30), and , 40778, testis 13 × 11 mm., 71.5 gm. (July 28), Pueblo Nuevo X-can.

Polioptila caerulea (Linnaeus): Blue-gray Gnatcatcher.--A fledgling taken at Pisté was barely flying with remiges and rectrices ensheathed basally. Previous breeding records are for April 11 and 27 (Paynter, 1955a:231). A male taken on August 10 on Isla Cozumel had nearly completed molting into winter plumage.

Specimens (8): [Female], 40788, fledgling, 5.0 gm. (July 20), 6-1/2 km. W Pisté; , 40787, testis 2 × 1 mm., 5.6 gm. (July 21), , 40785, juv., 5.8 gm. (July 22), and [Female], 40786, 5.6 gm. (July 22), Pisté; [Female], 40791, juv., 5.6 gm. (August 8), , 40790, juv., 5.8 gm. (August 8), [Female], 40789, 5.7 gm. (August 9), and , 40792, 5.3 gm., molting--7th primaries ensheathed (August 10), from {2-1/2}-{3-1/2} km. N San Miguel, Isla Cozumel.

Polioptila albiloris Lawrence: White-lored Gnatcatcher.--This species was abundant in the arid scrub along the coast in the vicinity of Sisal.

Specimens (2): , 40783, testis 1 mm., 6.2 gm. (August 7), 1-1/2 mi. S Sisal; , 40784, testis 1 mm., 5.8 gm. starting to molt--1st and 2nd primaries ensheathed (August 10), 13 km. WSW Sisal.

Ramphocaenus rufiventris (Bonaparte): Long-billed Gnatwren.--Specimen (1): [Female], 40793, imm. skull, 9.8 gm. (July 15), 7-1/2 km. W Escárcega.

Cyclarhis gujanensis insularis Ridgway: Rufous-browed Pepper-shrike. --Specimen (1): , 40794, testis 2 mm., 37.8 gm., molting--4th primaries ensheathed (August 9), 4 km. N San Miguel, Isla Cozumel.

Vireo bairdii (Ridgway): Cozumel Vireo.--Specimens (4): [Female], 40795, ovary inactive, 12.7 (August 8), , 40796, testis 2 mm., 12.6 gm., molting--3rd and 4th primaries ensheathed (August 10), [Female], 40797, ovary inactive, 12.5 gm., molting--3rd primaries ensheathed (August 10), and , 47098, imm., 13.1 gm. (August 10), from 2-1/2-3-1/2 km. N San Miguel, Isla Cozumel.

Vireo pallens semiflavus (Salvin): Mangrove Vireo.--Paynter (1955a:236) noted breeding by this species from April 7 through June.

Specimens (2): [Female], 40800, ova to 3 mm., oviduct enlarged (July 8), Isla del Carmen; [Female], 40799, ovary inactive, 11.1 gm., molting--4th primaries ensheathed (August 2), Isla Mujeres.

Vireo flavoviridus flavoviridus (Cassin): Yellow-green Vireo.--Paynter's (1955a:238) data indicate breeding in this species from late May through June; our records indicate that the species breeds at least through July.

Specimens (12): , 40812, testis 10 × 4 mm., 17.1 gm., molting--1st, 2nd, and 3rd primaries ensheathed (July 17), and , 40813, testis 7 × 4 mm., 18.2 gm. (July 17), 1 km. N, 13 km. W Escárcega; [Female], 40803, ovary 9 × 5 mm., ova to 1 mm., brood patch (July 21), , 40805, testis 11 × 6 mm., 18.5 gm. (July 21), , 40804, 18 gm. (July 21), and [Female], 40802, ovary slightly enlarged, molting--2nd and 3rd primaries ensheathed (July 21), all from Pisté; , 40806, 17.5 gm., molting--1st primaries ensheathed (July 21), 6-1/2 km. W Pisté; [Female], 40808, ovary 5 × 3 mm., 17.4 gm. (July 28), , 40807, testis 5 × 3 mm., 17.7 gm., molting--3rd and 4th primaries ensheathed (July 28), , 40809, testis 2 × 1 mm., 17.5 gm. (July 29), and , 40810, testis 3 × 2 mm., 18.7 gm., molting--1st, 2nd, 3rd, and 4th primaries ensheathed (July 30), from Pueblo Nuevo X-can; , 40811, testis 3 × 1 mm., 18.7 gm., molting--4th, 5th, and 6th primaries and middle pair of rectrices ensheathed (August 14), 4 km. NNE Felipe Carrillo Puerto. Mallophaga: Philopterus sp. July 21.

Vireo magister (Lawrence): Yucatán Vireo.--Breeding on the peninsula has not been recorded previously. A male, beginning to molt, taken on August 10 on Isla Cozumel had enlarged testes, which were apparently regressing.