Table 1.Contents of 10 burrows of Turquoise-browed Motmots.
* Nothing.x Broken egg shells.
* 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.
Possibly females of this species raise more than one brood in a single nesting season, but I have no direct evidence of this. Such an hypothesis is suggested by the different stages of nestings found in the burrows. Moreover, there were more than twice as many burrows as motmots in the area. The largest number of individuals counted at any time near the colony was 20 adults (about an hour after sunrise). Assuming that all of these birds had mates, the maximum number of adults present could have numbered about 40.
There is another bit of evidence for double broods. Because of fouling of the burrow that accompanies the raising of a brood of young, it seems improbable that a burrow would be used immediately for a second nesting attempt. Consequently digging a second burrow would be necessary, if a second brood is raised.
Most of my observations are in keeping with Skutch's detailed report (1947) of the species in Central America. According to him, eggs are laid in April and May in Honduras and Guatamala, although he did not state that breeding does not occur in other months. The observations in Campeche in early July suggest that breeding can occur over an extended period; Paynter (1955a:158) found the species to be in various stages of reproductive activity in April on the peninsula.
Skutch suggested that the motmots he observed in Central America were solitary nesters, and nest in "groups" only where suitable nesting sites are scarce. In Campeche, many suitable, seemingly identical, but unused, nesting sites were available within a few hundred yards of the site of the actual nesting "colony." Moreover, most of the burrows were only a few feet apart and no agonistic behavior was witnessed. It seems that this motmot is characterized by colonial nesting habits in Campeche, even where abundant sites for individual nesting efforts are available.
The species was abundant around thecenotesat Chichén-Itzá; adults with enlarged gonads and brood patches and juveniles were taken at Pisté as late as July 21.
Specimens (19): ♂, 40565, brood patch, 59.4 gm. (July 9), ♂, 40564, testis 8 × 4 mm., brood patch, 68.0 gm. (July 9), ♂, 40566, 74 gm. (July 9), ♀, 40567, juv. (July 9), ♂, 40568, testis 5 × 3 mm., 68.3 gm. (July 10), ♂, 40578, 59.5 gm. (July 11), and ♀, 40577, ova to 2 mm., brood patch, 65.2 gm. (July 11), all from 5 km. S Champotón; ♂, 40560, 43.6 gm. (July 20), ♀, 40562, brood patch, 55 gm. (July 21), sex? 40561, 64 gm. (July 21), and ♀, 40563, juv. (July 22), Pisté. Eight nestlings (40569-76) that were taken from burrows at 5 km. S Champotón on July 11 had the following weights: 42.4 gm., 39.7 gm., 38.5 gm., 12.2 gm., 40.0 gm., 30.7 gm., 26.8 gm., 19.0 gm. Mallophaga:Philopterussp., July 9.
Momotus momota lessoniiLesson: Blue-crowned Motmot.—For convenience, the specimens from 5 km. S Champotón are assigned toM. m. lessoniion the basis of measurements (wing 139 mm., tail 240 mm., culmen [from feathers] 41.0 mm.) taken on one specimen (40579), which are within the limits of the subspecies as described by Ridgway (1914). Two other specimens from that locality were prepared as skeletons and their weights are essentially the same as those Paynter (1955a) recorded forM. m. lessonii. According to Paynter, there is a southward clinal increase in size in this species between the smallerM. m. exiguusin the northern part of the peninsula andM. m. lessoniiin the extreme southern part. A more extensive series of specimens from the vicinity of Champotón probably would reveal a population intermediate in size between the typical representatives of the two races.
Specimens (3): ♀, 40579, 105 gm. (July 10), ♀, 40581, 98.9 gm. (July 11), ♂, 40580, 102.5 gm. (July 11), 5 km. S Champotón.
Pteroglossus torquatus erythrozonusRidgway: Collared Aracari.—A male taken at Pueblo Nuevo X-can on July 27 and a female from 4 km. NNE Felipe Carrillo Puerto on August 15 had slightly enlarged gonads, which probably were regressing. Apparently these are the first indications of breeding activity for this species on the peninsula.
Specimens (5): ♂, 40586, testis 4 × 2 mm., 155 gm. (July 16), 7½ km. W Escárcega; ♂, 40582, testis 10 × 5 mm., 169.1 gm. (July 27), and ♀, 40583, ovary inactive, 137.3 gm. (July 29), Pueblo Nuevo X-can; ♀, 40584, ovary 10 × 6 mm., 169.5 gm. (August 15), and sex? 40585, 148.9 gm. (August 16), 4 km. NNE Felipe Carrillo Puerto.
Rhamphastos sulfuratus sulfuratusLesson: Keel-billed Toucan.—This species was especially common west of Escárcega, where it was most often seen in small flocks of less than 10 birds. Presumably breeding had already occurred; four specimens had inactive gonads.
Specimens (7): ♀, 40589, 367.3 gm. (July 12), ♂, 40588, testis 8 × 3 mm., 414.5 gm. (July 14), ♀, 40590, ovary 11 mm., 347.4 gm. (July 15), ♂, 40591, testis 5 × 3 mm., 371 gm. (July 15), ♂, 40593, testis 6 × 3 mm., 422.2 gm. (July 16) and ♂, 40592, 401.5 gm. (July 16), 6-7½ km. W Escárcega; ♀, 40587, 395.5 gm. (July 28), Pueblo Nuevo X-can.
Piculus rubiginosus yucatanensis(Cabot): Red-capped Green Woodpecker.—Specimen (1): ♀, 40594, ovary inactive (7 × 4 mm.), extensive body molt, 67.7 gm. (August 17), 4 km. NNE Felipe Carrillo Puerto. Mallophaga:Penerirmussp.
Drycopus lineatus similis(Lesson): Lineated Woodpecker.—Specimen (1): ♂, 40595, molting, 141.2 gm. (July 15), 7½ 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 toC. a. dubius, following the systematic treatment by Selander and Giller (1963).
Specimens (10): sex? 40602, 75.0 gm. (July 8), and ♀, 40601, ovary 6 × 3 mm. (enlarged oviduct), 76.4 gm. (July 10), 1 km. S Puerto Real, Isla del Carmen; ♂, 40599, testis 6 × 8 mm., 101.3 gm. (July 10), and ♂, 40600, 86.0 gm. (July 11), 5 km. S Champotón; ♂, 40603, testis 5 × 3 mm. (July 14), and ♀, 40604, ovary 6 × 4 mm. (ova to 1 mm.), brood patch (July 16), 7½ km. W Escárcega; sex? 40596, molting, much visceral fat, 79.0 gm. (July 22), Pisté; ♀, 40597, 73.7 gm. (July 28), Pueblo Nuevo X-can; ♀, 40598, 79.6 gm. (August 15), 4 km. NNE Felipe Carrillo Puerto; ♂, 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): ♂, 40608, testis 6 × 4 mm. (July 10); ♀, 40607, 39.5 gm. (July 10), 5 km. S Champotón; ♂, 40609, testis inactive, 35.8 gm., moderate visceral fat (July 17), 1 km. N, 13 km. W Escárcega; ♀, 40606, ovary 6 × 4 mm. (inactive), 37.0 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto; ♂, 40610, testis inactive, heavy visceral and subcutaneous fat, 41.6 gm., (August 10), 3½ km. N San Miguel, Isla Cozumel.
Phloeoceastes guatemalensis guatemalensis(Hartlaub): Guatemalan Ivory-billed Woodpecker.—Specimens (4): ♂, 40611, right testis 2 mm., left testis vestigial, 203.7 gm. (July 23), Pisté; 40612, sex? 212 gm., (July 28), and ♀, 40613, 218.1 gm. (July 30), Pueblo Nuevo X-can; ♀, 40614, 189.2 gm. (August 15), 4 km. NNE Felipe Carrillo Puerto.
Dendrocincla anabatina(Sclater): Tawny-winged Woodhewer.—Specimen (1): ♂, 40615, testis 2 × 1 mm., 35.7 gm., molting—5th primaries and middle pair of rectrices ensheathed (July 17), 1 km. N, 13 km. W Escárcega.
Dendrocincla homochroa homochroa(Sclater): Ruddy Woodhewer.—May 20 seems to be the only previous date of record for breeding in this species (Paynter, 1955a:171); our specimen extends the known season nearly three months.
Specimen (1): ♀, 40616, ovary 13 × 6 mm. (ova to 2 mm.), brood patch, 35.1 gm. (August 16), 4 km. NNE Felipe Carrillo Puerto.
Sittasomus griseicapillus(Vieillot): Olivaceous Woodcreeper.—Specimens (2): ♂, 40617, juv., 11.2 gm. (July 26), Pisté; ♀, 40618, ovary inactive, 10.5 gm. (August 15), 4 km. NNE Felipe Carrillo Puerto.
Xiphorhynchus flavigaster(Swainson): Ivory-billed Woodcreeper.—According to Paynter (1955a:173), indications of breeding have been observed in specimens of this species taken between March 27 and June 5. A male taken on August 15 had moderately enlarged (probably regressing) testes and was well into the molt.
Specimen (1): ♂, 40619, testis 5 × 3 mm., 51.5 gm., molting—5th primaries and middle pair of rectrices ensheathed (August 15), 4 km. NNE Felipe Carrillo Puerto.
Lepidocolaptes souleyetii(Des Murs): Streak-headed Woodhewer.—This appears to be the second specimen recorded from the peninsula (see Traylor, 1941).
Specimen (1): ♂, 40621, testis 3 × 1 mm., 26.6 gm., molting—6th primaries ensheathed, middle pair of rectrices are new (July 17), 1 km. N, 13 km. W Escárcega.
Synallaxis erythrothoraxSclater: Rufous-breasted Spinetail.—Specimen (1): ♂, 40622, imm. skull, 16.1 gm. (August 16), 4 km. NNE Felipe Carrillo Puerto.
Thamnophilus doliatus(Linnaeus): Barred Antshrike.—Specimen (1): ♀, 40623, ovary 8 × 5 mm. (inactive), 26 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto.
Formicarius analis(d'Orbigny and Lafresnaye): Black-chinned Antthrush.—Specimen (1): ♂, 40624, 56.0 gm. (July 29), Pueblo Nuevo X-can.
Pachyramphus major itzensisNelson: Mexican Becard.—Previous records of breeding in this species are provided by a female obtained on July 12 (Paynter, 1955a:182) and a male taken on June 9 (Paynter, 1955b).
Specimen (1): ♂, 40625, testis 9 × 5 mm., 22.1 gm. (July 21), Pisté.
Platypsaris aglaiae(Lafresnaye): Rose-throated Becard.—All specimens have extensively worn plumage.
Specimens (3): ♂, 40628, 33.5 gm. (July 10), 5 km. S Champotón; ♀, 40626, ovary 6 × 3 mm., brood patch, 34.0 gm. (July 20), ♀, 40627, ovary inactive, 33.9 gm. (July 26); 3½ km. N and 6½ km. W Pisté.
Tityra semifasciata personataJardine and Selby: Masked Tityra.—Previously, breeding information for this species has been available only for March (Paynter, 1955a:184). Adults were observed feeding young fledglings 7½ km. W Escárcega on July 15, and a juvenile was taken. Gonads of males were in full breeding condition.
Specimens (5): ♂, 40630, testis 13 × 6 mm., 81.3 gm. (July 14), sex? 40631, juv., 55.5 gm. (July 15), ♂, 40632, testis 9 × 5 mm., 73 gm., molting—1st and 2nd primaries ensheathed (July 15), and ♀, 40633, 84.7 gm. (July 16), 7½ km. W Escárcega; ♀, 40629, ova to 1 mm., 80.0 gm. (July 23), Pisté.
Erator inquisitor fraserii(Kaup): Black-capped Tityra.—Breeding has been recorded by Paynter (1955a:185) on April 26. A moderately enlarged testis (probably regressing) was noted in the specimen from Pisté, on July 21.
Specimens (2): ♀, 40635, 51.8 gm. (July 15), 7½ km. W Escárcega; ♂, 40634, testis 6 mm., 51 gm., molting—6th primaries ensheathed (July 21), Pisté.
Pipra mentalis mentalisSclater: Red-capped Manakin.—The specimens here reported seem to be the first from the peninsula in which reproductive activity has been recorded.
Specimens (2): ♂, 40637, testis 5 × 3 mm., 14.0 gm. (July 29), Pueblo Nuevo X-can; ♂, 40636, testis 5 × 2 mm., 14.6 gm. (August 3), 4 km. WSW Puerto Juarez.
Pyrocephalus rubinus(Boddaert): Vermillion Flycatcher.—This species was seen only in the arid scrub 2-13 km. WSW of Sisal. Breeding seemingly had ended by early August, as evidenced by four adults that showed no gonadal activity and were in advanced stages of molt.
Specimens (5): ♀, 40638, juv., 12.1 gm. (August 7), 1½ mi. S Sisal; ♀, 40640, ovary inactive, 14.1 gm., molting—6th primaries ensheathed (August 10), ♀, 40641, ovary inactive, 13.9 gm., molting—7th primaries ensheathed (August 10), and ♂, 40642, testis 2 mm., 14.6 gm., molting—5th primaries ensheathed (August 10), 13 km. WSW Sisal; ♀, 40639, testis 1 mm., 14.0 gm., molting—7th primaries ensheathed (August 18), 2 km. SW Sisal.
Tyrannus melancholicus chloronotusBerlepsch: Tropical Kingbird.—Most specimens were molting. A male and two females from Pisté taken on July 21 and a female from Pueblo Nuevo X-can (July 29) had slightly enlarged (probably regressing) gonads. Three immatures were collected and adults were seen feeding young fledglings at Pisté. There seems to be no other breeding records from the peninsula.
Specimens (10): ♀, 40650, 42 gm., (July 10), 5 km. S Champotón; ♀, 40752, ovary inactive, 43.4 gm., molting—4th primaries ensheathed (July 14), and ♂, 40651, imm., 42.5 gm. (July 15), 6-7½/# km. W Escárcega; ♀, 40645, ovary slightly enlarged (8 × 3 mm.), 47.5 gm. (July 21), ♀, 40643, ova to 1 mm., 39.3 gm. (July 21), ♂, 40644, testis 10 × 7 mm., 43.1 gm., starting to molt—1st primaries ensheathed (July 21), and ♀, 40646, imm., (July 26), Pisté; ♀, 40648, ova to 1 mm., 37.4 gm. (July 29), Pueblo Nuevo X-can; ♂, 40647, imm., 38.4 gm. (August 14), and ♀, 40649, 44.4 gm., molting—only outer 3 pairs of rectrices present and are ensheathed basally, 6th and 7th primaries ensheathed (August 15), 4 km. NNE Felipe Carrillo Puerto.
Myiodynastes luteiventris luteiventrisSclater: Sulfur-bellied Flycatcher.—The latest breeding record given by Paynter (1955a:191) is for the last week in June. A male taken on July 31 had enlarged testes. None of the following specimens was in the process of molt.
Specimens (4): ♀, 40655, 44.5 gm. (July 10), 5 km. S Champotón; ♀, 40656, ovary slightly enlarged (8 × 4 mm.), 47.0 gm. (July 15), 7½ km. W Escárcega; ♀, 40654, testis 10 × 4 mm., 39 gm. (July 31), Pueblo Nuevo X-can.
Megarhynchus pitangua mexicanus(Lafresnaye): Boat-billed Flycatcher.—I know of no previous breeding record for this species on the peninsula. The female obtained on July 25 was observed feeding young.
Specimens (2): ♀, 40658, 57.6 gm. (July 11), 5 km. S Champotón; ♀, 40657, ovary 10 × 5 mm., 59.8 gm. (July 25), Cenote Seco, 2 km. E Chichén-Itzá.
Myiozetetes similis texensis(Giraud): Vermilion-crowned Flycatcher.—Paynter (1955a:192) reported this species breeding in mid-May. A male taken on July 17 west of Escárcega had enlarged (probably regressing) testes and indicates breeding later than May.
Specimens (3): ♂, 40660, testis 6 × 3 mm., 32.0 gm. (July 17), and sex? 40661, 33.8 gm., molting—5th primaries ensheathed (July 17), 1 km. N, 13 km. W Escárcega; ♂, 40659, imm., testis 2 × 1 mm., 27.6 gm. (July 29), Pueblo Nuevo X-can.
Pitangus sulphuratus guatimalensis(Lafresnaye): Great Kiskadee.—Apparently our specimens, which were in the late stages of breeding, are the first evidence of reproduction for the species on the peninsula.
Specimens (4): ♀, 40663, ova to 1 mm., 50.7 gm. (July 9), and ♂, 40664, right testis 12 mm., 65.0 gm., body feathers in early stages of molt (July 9), 5 km. S Champotón; ♂, 40665, testis 5 mm., 61.9 gm., molting—middle pair of rectrices are new, 6th primaries ensheathed (July 15), 7½ km. W Escárcega; sex? 40662, 59.5 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto. Mallophaga:Philopterussp.
Myiarchus tyrannulus cooperiBaird: Wied Flycatcher.—This species was especially common among the coco palms on Isla del Carmen and Isla Cozumel.
Specimens (5): ♂, 40667, 36.7 gm. (July 8), ♂, 40668, 36.6 gm. (July 8), sex? 40669, 39.4 gm. (July 8), and ♀, 40670, 37.3 gm. (July 8), all from 1 km. SW Puerto Real, Isla del Carmen; ♀, 40666, ovary inactive, 34.9 gm. (August 10), 3 km. N San Miguel, Isla Cozumel.
Myiarchus tuberculifer platyrhynchusRidgway: Olivaceous Flycatcher.—Breeding specimens of this species have been known previously from April and May (Paynter, 1955a:196); records listed beyond extend the season nearly three months.
Specimens (7): ♀, 40673, ova to 5 mm. (July 10), and ♀, 40674, ovary 7 × 3 mm. (ova to 1 mm.) (July 11), 5 km. SW Champotón; ♀, 40745, ovary inactive, 17.5 gm., starting to molt—1st, 2nd, and 3rd primaries ensheathed (July 16), 7½ km. W Escárcega; ♀, 40671, imm., 16.1 gm. (July 20) Cenote Seco, 2 km. E Chichén-Itzá; ♂, 40746, 18.2 gm. (July 22), Pisté; ♀, 40672, ovary inactive, 17.7 gm., molting—5th and 6th primaries and 1st secondaries ensheathed (August 15), 4 km. NNE Felipe Carrillo Puerto; ♂, 40675, left testis 13 mm., right testis 10 mm., 17.5 gm. (August 8), 3½ km. N San Miguel, Isla Cozumel.
Contopus cinereus(Spix): Tropical Pewee.—The regressing gonads of the male taken on July 21 in an early stage of molt suggests breeding on the peninsula.
Specimens (2): ♂, 40676 testis 6 × 3 mm., 11.5 gm., starting to molt—1st and 2nd primaries ensheathed (July 21), 6½ km. W Pisté; ♂, 40677, testis 1 mm., 12.6 mm., molting—4th, 5th, and 6th primaries and 2nd secondaries ensheathed (August 14), 4 km. NNE Felipe Carrillo Puerto.
Tolmomyias sulphurescens(Spix): Sulphury Flat-Billed Flycatcher.—Paynter (1955a:201) presented breeding records for this species from mid-April to late June. My specimens seem to indicate that breeding extends at least into July.
Specimens (6): ♀, 40683, juv., 14.0 gm. (July 21), ♂, 40684, juv. (remiges and rectrices ensheathed basally), 14.0 gm. (July 21), and ♂, 40682, testis 8 × 4 mm., 13.7 gm. (July 26), Pisté and 3½ km. N Pisté; ♂, 40685, testis 7 × 4 mm., 15.3 gm., molting—1st and 2nd primaries ensheathed (July 28), and ♀, 40686, ovary inactive (July 28), Pueblo Nuevo X-can; ♂, 40687, imm., 16.0 gm. (August 15), 4 km. NNE Felipe Carrillo Puerto. Mallophaga:Philopterussp. July 28;Myrsideasp. July 28.
Myiopagis veridicata(Vieillot): Yellow-crowned Elaenia.—The only previous breeding record is of a male that was taken on April 29. My only specimen has nearly fully enlarged testes.
Specimen (1): ♂, 40688, testis 7 × 4 mm., 13.1 gm. (July 17), 1 km. N, 13 km. W Escárcega.
Progne subis subis(Linnaeus): Purple Martin.—A large migrant flock of several thousand individuals of this species was present for several days in August at Rancho San Miguel.
Specimens (3): ♀, 40723, ovary inactive, 48.6 gm. (August 14), ♀, 40724, 51.8 gm. (August 17), and ♀, 40725, imm. skull, 52.1 gm. (August 17), 4 km. NNE Felipe Carrillo Puerto.
Petrochelidon fulva citataVan Tyne: Cave Swallow.—Throughout our stay at Pisté, large numbers of Cave Swallows were seen flying in and out of the small opening of a well-likecenotein the center of the village. Specimens were easily collected in a mist net placed across the opening. No young Cave Swallows were taken and gonads of adults were in various stages of reproductive activity. A few individuals taken were beginning to molt. Probably the swallows were nesting in thecenotealthough the nests were inaccessible to view. Previous breeding records are for April (Paynter, 1955a:209).
Twenty-two specimens were collected, of which the following were taken at Pisté, July 21-25: ♂, 40693, testis 6 × 3 mm., 18.4 gm.; ♂, 40696, 16.4 gm.; ♀, 40697, 18.2 gm.; ♂, 40695, 15.0 gm.; ♀, 40690, ovary inactive, 18.4 gm., molting—2nd primaries ensheathed; ♂, 40692, testis 5 × 3 mm., 17.9 gm.; ♀, 40698, 18.3 gm.; ♀, 40702, ovary 7 × 3 mm., 18.9 gm.; ♀, 40703, ovary 6 × 3 mm., 17.5 gm.; ♂, 40713, testis 3 mm., 18.4 gm.; ♀, 40704, 16.5 gm.; ♂, 40705, 20.3 gm.; ♂, 40699, testis 2 mm., 18.6 gm., molting—2nd primaries ensheathed; ♀, 40700, ovary 5 × 3 mm., 18.5 gm., molting—1st primaries ensheathed; ♀, 40701, ovary 5 × 3 mm., 16.5 gm., molting—1st primaries ensheathed; ♂, 40707, testis 7 × 5 mm., 19.9; ♂, 40708, testis 4 × 3 mm., 18.4 gm.; ♀, 40709, ovary 4 × 3 mm., 18.0 gm.; sex? 40711, 18.3 gm., molting—1st and 2nd primaries ensheathed.
Additional specimens are: ♀, 40718, 16.5 gm., molting—3rd primaries ensheathed (August 16), and ♀, 40719, 18.5 gm., molting 1st primaries ensheathed (August 16), 4 km. NNE Felipe Carrillo Puerto; ♂, 40689, testis 1 mm., 16.2 gm., molting—2nd primaries ensheathed (August 10), 13 km. WSW Sisal. Mallophaga:Philopterus excisus, July 21;Myrsideasp. July 21 and 25.
Stelgidopteryx ruficollisAudubon: Rough-winged Swallow.—Previous records indicate that three subspecies of this species occur on the Yucatán Peninsula (Paynter, 1955a:209). One of these,S. r. ridgwayi, is resident.S. r. serripennis, representing the breeding population occurring from British Columbia and New Hampshire over much of the United States to central California, central Texas, and the Gulf states, has been taken on the peninsula in winter. Paynter referred two specimens taken in late September and three January-taken specimens toS. r. stuarti, the highland race that breeds from the mountains of southern Veracruz to Guatamala.
Allan R. Phillips had identified two immature individuals (40694 and 40712) from Pisté asS. r. stuarti; one specimen from Puerto Juarez also is an immature and is nearly identical to those from Pisté. Two adults from Pisté (40691 and 40710) are noticeably darker dorsally than the immatures but are molting extensively and their identification to subspecies is equivocal. Two other adults (40706 and 40715) were prepared as skeletons.
Although mid-July seems early forS. r. stuartito be present on the peninsula it is not too surprising since the three specimens positively identified are immature birds and young possibly arrive earlier than do adults. But, the immature specimens possibly are atypical individuals of the resident population ofS. r. ridgwayi.
Except for the immature individual from 5 km. WSW Puerto Juarez, all specimens were taken in mist nets over thecenoteat Pisté wherePetrochelidon fulvaalso was obtained.
Specimens (7): ♂, 40694, imm., 16.2 gm., ♀, 40691, ovary inactive, 16.4 gm., molting—general body molt, 5th primaries and middle pair of rectrices ensheathed, ♀, 40712, imm., 14.5 gm., ♀, 40706, 14.8 gm., ♂, 40715, 16.4 gm., ♂, 40710, 18.5 gm., molting—general body molt, 1st primaries and middle pair of rectrices ensheathed, all from Pisté, July 21 and 25; ♂, 40720, imm., 15.5 gm. (August 1), 5 km. WSW Puerto Juarez.
Hirundo rustica erythrogasterBoddaert: Barn Swallow.—Specimen (1): ♀, 40721, imm., 7.3 gm. (August 18), apparently an early migrant, 2 km. WSW Sisal.
Iridoprocne albilinea(Lawrence): Mangrove Swallow.—Specimen (1): ♀, 40722, imm. (July 7), Puerto Real, Isla del Carmen.
Cissilopha yucatanica(Dubois): Yucatán Jay.—Heretofore, breeding activity has been recorded only in March (Paynter, 1955a:217). All specimens in my collection have extensively worn plumage and were beginning to molt.
Specimens (6): ♂, 40726, left testis 9 × 7 mm., right testis 4 × 2 mm., brood patch, 122.3 gm., molting—1st and 2nd primaries ensheathed (July 10), 5 km. S Champotón; ♂, 40727, testis 5 × 3 mm., brood patch, 125.6 gm., molting—1st and 2nd primaries ensheathed (July 11), 5 km. SW Champotón; ♀, 40728, 109.8 gm. (July 13), and sex? 40729, 109.5 gm. (July 15), 7½ km. W Escárcega; ♀, 40730, imm., 110.3 gm. (July 21), Pisté; ♀, 40731, ovary inactive, brood patch refeathering, 121 gm., molting—2nd and 3rd primaries ensheathed (August 16), 4 km. NNE Felipe Carrillo Puerto.
Cyanocorax yncas maya(van Rossem): Green Jay.—There are records of breeding by this species on the peninsula for April 28 and 29, and June 4 (Paynter, 1955a:215, 216).
Specimens (4): ♂, 40740, testis 5 × 3 mm., 81.2 gm. (July 16), 7½ km. W Escárcega; ♀, 40739, juv., 62.3 gm. (July 21), ♂, 40737, 64.5 gm. (July 21), and ♀, 40738, 64.1 gm. (July 21), Pisté.
Psilorhinus morio(Wagler): Brown Jay.—Specimens (3): ♀, 40742, 203.5 gm. (July 13), ♂, 40743, juv., 170 gm. (July 14), 7½ km. W Escárcega; ♂, 40741, juv., 193.7 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto.
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 consideralbinuchato be a subspecies ofT. 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): ♀, 40758, ovary (6 × 3 mm.) granular (July 14), and ♂, 40757, testis 5 × 3 mm., 15.3 gm. (July 14), 7½ km. W Escárcega; ♀, 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): ♀, 40760, juv. (August 2), 4 km. WSW Puerto Juarez.
Troglodytes beani(Ridgway): Cozumel Wren.—Specimens (2): ♀, 40761, 13.3 gm. (August 9), and ♂, 40762, imm., 13.6 gm. (August 9), 3½ 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), 1½ mi. SW Sisal; ♀, 40751, imm., 31.2 gm. (August 18), 2 km. WSW Sisal; ♀, 40752, ovary 7 × 3 mm., 40 gm. (August 9), 4.3 km. WSW Sisal; ♀, 40753, 31.0 gm. (August 11), 6½ 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), ♀, 40767, testis 8 × 4 mm., 42.0 gm., heavy fat (August 8), ♀, 40765, ovary active (oviduct enlarged), brood patch, 35.2 gm. (August 10), and ♂, 40766, testis 9 × 6 mm., 35 gm. (August 10), from 2½-3½ 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; ♀, 40770, ovary moderately active (ova to 2 mm.), brood patch, 42 gm., moderate fat (August 9), 3½ km. N San Miguel, Isla Cozumel; ♀, 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:Myrsideasp., 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), 3½ km. N San Miguel, Isla Cozumel.
Turdus grayiBonaparte: 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; ♀, 40781, ova to 8 mm., 79.6 gm. (July 15), 5 km. SW Escárcega; ♀, 40776, 61.3 gm. (July 21), Pisté; ♀, 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): ♀, 40788, fledgling, 5.0 gm. (July 20), 6½ km. W Pisté; ♂, 40787, testis 2 × 1 mm., 5.6 gm. (July 21), ♂, 40785, juv., 5.8 gm. (July 22), and ♀, 40786, 5.6 gm. (July 22), Pisté; ♀, 40791, juv., 5.6 gm. (August 8), ♂, 40790, juv., 5.8 gm. (August 8), ♀, 40789, 5.7 gm. (August 9), and ♂, 40792, 5.3 gm., molting—7th primaries ensheathed (August 10), from {2½}-{3½} km. N San Miguel, Isla Cozumel.
Polioptila albilorisLawrence: 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), 1½ 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): ♀, 40793, imm. skull, 9.8 gm. (July 15), 7½ km. W Escárcega.
Cyclarhis gujanensis insularisRidgway: 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): ♀, 40795, ovary inactive, 12.7 (August 8), ♂, 40796, testis 2 mm., 12.6 gm., molting—3rd and 4th primaries ensheathed (August 10), ♀, 40797, ovary inactive, 12.5 gm., molting—3rd primaries ensheathed (August 10), and ♂, 47098, imm., 13.1 gm. (August 10), from 2½-3½ 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): ♀, 40800, ova to 3 mm., oviduct enlarged (July 8), Isla del Carmen; ♀, 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; ♀, 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 ♀, 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), 6½ km. W Pisté; ♀, 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:Philopterussp. 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.
Specimens (3): ♀, 40814, ovary inactive, 17.7 gm. (August 2), Isla Mujeres; sex? 40815, 19.5 gm. (August 9), and ♂, 40816, testis 6 × 3 mm., 20.2 gm., molting—1st, 2nd, and 3rd primaries ensheathed (August 10), 3½ km. N San Miguel, Isla Cozumel.
Cyanerpes cyaneus carneipes(Sclater): Blue Honeycreeper.—Paynter (1955a:283) collected specimens that were breeding in April. Testes were fully enlarged in two August-taken specimens and courtship rituals were observed in two pairs seen on August 3 at Puerto Juarez.
Specimens (3): ♂, 40817, 15.5 gm. (July 21), 6½ km. W Pisté; ♂, 40818, testis 12 × 6 mm., 12.1 gm. (August 3), 4 km. WSW Puerto Juarez; ♂, 40819, testis 8 × 6 mm., 11.6 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto.
Coereba flaveola caboti(Ridgway): Bananaquit.—Specimen (1): ♀, 40820, ovary inactive, 5 × 3 mm., 11.0 gm., molting—1st and 2nd primaries ensheathed, 3rd and 4th primaries missing (August 10), 3½ km. N San Miguel, Isla Cozumel.
Dendroica petechia rufivertex(Ridgway): Yellow (Golden) Warbler.—Specimens (5): ♀, 40831, ovary inactive, 8.0 gm. (August 8), sex?, 40832, imm. (fresh, first winter plumage), 10 gm. (August 8), ♀, 40830, ovary inactive, 10.0 gm., molting—4th and 5th primaries ensheathed (August 9), ♀, 40833, ovary inactive, 8.5 gm. (August 9), and ♀, 40834, ovary inactive, 7.8 gm. (August 10), all from 3½-4 km. N San Miguel, Isla Cozumel.
Dendroica petechia bryanti(Ridgway): Yellow (Mangrove) Warbler.—Previous records of breeding by this species are available for March 29 and 30 and May 16 (Paynter, 1955a:247). Breeding apparently continues at least into July. An adult male with moderately enlarged testes (probably regressing) was taken on July 7 at Zacatel, Campeche, and a juvenile was obtained 13 km. WSW Sisal on August 10. The male at Zacatal was in mangroves alongside the ferry landing (for the ferry from Isla del Carmen) and seems to be the first specimen of this subspecies recorded for the state.
Specimens (7): ♂, 40829, testis 4 × 2 mm., 11.1 gm., molting—1st, 2nd, and 3rd primaries ensheathed (July 7), Zacatal, Campeche; ♂, 40823, imm., 10.0 gm. (August 9), ♂, 40824, testis 1 mm., 13.0 gm., molting—4th and 5th primaries and middle three rectrices ensheathed (August 9), ♂, 40826, juv., 10.1 gm. (August 10), ♂, 40827, imm. (fresh, first winter plumage), 10.2 gm. (August 10), sex?, 40825, 10.3 gm. (August 10), and ♂, 40828, testis 2 mm., molting—7th, 8th, and 9th primaries, 2nd, and 3rd secondaries and outer pair of rectrices ensheathed (August 11), all from 13 km. WSW Sisal.
Seiurus motacilla(Vieillot): Louisiana Waterthrush.—Our specimen, apparently an early migrant, was taken near the aguada at Rancho San Miguel.
Specimen (1): ♂, 40835, testis minute, 19.9 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto.
Tangavius aeneus aeneus(Wagler): Red-eyed Cowbird.—A male having enlarged testes taken on August 14 seems to be the first record of breeding in the species for the peninsula.
Specimens (2): ♂, 40838, testis 11 × 7 mm., 66.9 gm. (August 14), and ♀, 40839, ovary 6 mm., 60 gm. (August 15), 4 km. NNE Felipe Carrillo Puerto.
Cassidix mexicanus(Gmelin): Boat-tailed Grackle.—Specimen (1): ♂, 40840, 223.3 gm. (July 9), 1 km. SW Puerto Real, Isla del Carmen.
Dives dives dives(Deppe): Sumichrast Blackbird.—This species previously has been known to breed in May (Paynter, 1955a:263). The specimens from July had moderately active ovaries.
Specimens (2): ♀, 40842, ovary 8 × 4 mm., 92 gm. (July 11), 5 km. SW Champotón; ♀, 40841, ovary 11 × 5 mm., 88.6 gm. (July 21), Pisté.
Icterus prosthemelas(Strickland): Black-cowled Oriole.—Specimens (2): ♀, 40843, ovary 5 × 3 mm., 28.8 gm., molting—extensive body molt, 1st, 2nd, and 3rd primaries ensheathed (August 3), 4 km. WSW Puerto Juarez; ♂, 40844, testis 2 × 1 mm., 31.0 gm., molting 1st, 2nd, 3rd, and 4th primaries ensheathed (August 16), 4 km. NNE Felipe Carrillo Puerto.
Icterus mesomelas(Wagler): Yellow-tailed Oriole.—Our specimens extend the known breeding season; previous records are for April and May (Paynter, 1955a:265).
Specimens (4): ♂, 40848, testis 11 × 5 mm. (July 14), 7½ km. W Escárcega; ♂, 40846, juv. (rectrices and remiges ensheathed basally), 30.3 gm. (July 29), and ♂, 40847, testis 12 mm., 38.0 gm. (July 29), Pueblo Nuevo X-can; ♀, 40845, ovary 6 × 3 mm., 32.5 gm. (August 4), 4 km. WSW Puerto Juarez.
Icterus auratusBonaparte: Orange Oriole.—Paynter (1955a:266) reported breeding specimens taken in April and May. Two males taken in late July had fully enlarged testes.
Specimens (2): ♂, 40849, testis 10 × 6 mm., 32.5 gm. (July 28), Pueblo Nuevo X-can; ♂, 40850, testis 11 × 7 mm., 33.0 gm. (July 30), 1½ km. S, 1 km. E Pueblo Nuevo X-can.
Icterus gularis(Wagler): Black-throated Oriole.—Breeding in this species was reported by Paynter (1955a:267) only for the month of April. Breeding was apparently nearing an end in late July at Pisté, where several juveniles were taken. Adult males had moderately enlarged testes.
Specimens (8): ♂, 40858, testis 5 × 3 mm., 67.2 gm. (July 20), 6½ km. W Pisté; ♂, 40853, 59.0 gm. (July 21), ♀, 40851, imm., 49.9 gm. (July 21), ♂, 40852, 56.4 gm. (July 21), ♀, 40855, imm., 49.9 gm. (July 22), ♀, 40856, ovary inactive, 50.0 gm. (July 22), ♂, 40854, testis 6 × 4 mm., 63.8 gm. (July 22), and ♂, 40857, juv. (all rectrices and remiges ensheathed basally), 30.4 gm. (July 27), all from Pisté.
Icterus cucullatusNelson: Hooded Oriole.—This species has not heretofore been recorded as breeding on Isla Cozumel; testes were nearly fully enlarged but probably regressing in the only specimen taken there. It had been banded (USF&WS no. 601-87003) on the island in 1961 as an adult. According to Paynter (1955a:269) there are no breeding records for this species on the mainland later than April, March 25 being the earliest date. The species was observed nesting on Isla del Carmen and adult males taken there and 5 km. S Champotón in early July were in full breeding condition.
Specimens (6): ♂, 40863, testis 11 × 7 mm., 26.3 gm. (July 8), ♀, 40864, 31.4 gm. (July 8), and ♂, 40862, testis 11 × 5 mm., 24.7 gm. (July 8), 1 km. SW Puerto Real, Isla del Carmen; ♂, 40860, 26.5 gm. (July 9), and ♂, 40861, testis 10 × 5 mm., 20.9 gm. (July 11); 5 km. S Champotón; ♂, 40859, testis 8 × 5 mm., molting—7th primaries ensheathed, 27.0 gm. (August 8), 3.5 km. N San Miguel, Isla Cozumel.
Tanagra affinis affinisLesson: Lesson Euphonia.—Specimens (2): ♀, 40866, 8.8 gm. (July 22), Pisté; ♂, 40865, testis 3 × 2 mm., 10.0 gm. (August 3), 4 km. WSW (Aeropuerto) Puerto Juarez.
Tanagra lauta lautaBangs and Penard: Thick-billed Euphonia.—According to Paynter (1955a:272), the only breeding record previously available is that of a male having slightly enlarged testes on February 12. Males taken on July 15 and on August 14 had fully enlarged testes; the gonads of several other specimens were apparently regressing, two specimens had begun to molt, and juveniles were molting into first winter plumage.
Specimens (9): ♂, 40874, testis 7 × 4 mm. (July 15), and ♀, 40875, ova to 1 mm. (July 15), 7½ km. W Escárcega; ♂, 40869, testis 6 × 4 mm., 14.5 gm. (August 14), ♂, 40870, testis 2 mm., 14.5 gm., molting—5th primaries ensheathed (August 14), ♂, 40867, imm., 12.6 gm. (August 14), ♀, 40868, imm., 14.4 gm. (August 14), ♂, 40871, testis 2 mm., 14.4 gm., molting—2nd, 3rd, and 4th primaries ensheathed (August 14), ♀, 40872, ovary granular, 7.8 gm. (August 14), and ♀, 40873, ovary granular, 13.0 gm. (August 15), all taken 4 km. NNE Felipe Carrillo Puerto.
Thraupis abbas(Deppe): Yellow-winged Tanager.—Paynter (1955a:273) reported breeding in this species in late April and late June. Gonads in our specimens were moderately active.
Specimens (2): ♂, 40877, testis 6 × 4 mm., 43.0 gm., molting—1st and 2nd primaries ensheathed (July 15), 1 km. N, 13 km. W Escárcega; ♀ 40876, ovary 7 × 4 mm., (ova to 1 mm.), 42.1 gm. (July 29), Pueblo Nuevo X-can.
Spindalis zena benedictiRidgway: Stripe-headed Tanager.—Two males in advanced molt but with enlarged gonads were taken on August 9 and 10 and seem to be the first records indicating breeding in this species on Isla Cozumel.
Specimens (3): ♂, 40878, testis 9 × 7 mm., 32 gm., molting—5th primaries and middle pair of rectrices ensheathed (August 9), ♂, 40880, testis 5 × 3 mm., 30.0 gm., molting—3rd, 4th, 5th primaries and middle two pairs of restrices ensheathed (August 10), and ♀, 40879, ovary inactive, 28.1 gm., molting—remiges are new; secondary coverts ensheathed (August 10), 3½ km. N San Miguel, Isla Cozumel.
Piranga roseogularis(Cabot): Rose-throated Tanager.—Breeding has been previously recorded from March 17 through May 11 (Paynter, 1955a:276). Our only specimen, a male in advanced molt, had enlarged (regressing) testes.
Specimen (1): ♂, 40881, testis 7 × 5 mm., 24.2 gm., molting—4th and 5th primaries ensheathed (August 15), 4 km. NNE Felipe Carrillo Puerto.
Habia gutturalis(Sclater): Red-throated Ant-tanager.—The only breeding records previously available for this species on the peninsula are for May 18 (Paynter, 1955a:280) and June 25 (Paynter, 1955b). Specimens taken between July 14 and August 2 were in full breeding condition. A male (40882) and female (40883) taken 7½ km. W Escárcega were known to be mated. Plumages in all specimens are worn and for that reason specimens were not identified to subspecies.
Specimens (6): ♂, 40882, testis 14 × 9 mm., 38.9 gm. (July 14), ♀, 40883, ovary 5 × 5 mm., 29.0 gm. (July 14), and ♂, 40887, testis 10 × 7 mm. (July 16), 7½ km. W Escárcega; ♂, 40885, juv. (rectrices and remiges ensheathed basally) (July 28), and ♀, 40886, ovary moderately active, 30.5 gm., molting—2nd primaries ensheathed (July 28), Pueblo Nuevo X-can; ♂, 40884, testis 15 × 8 mm. (August 2), 4 km. WSW Puerto Juarez.
Saltator atriceps(Lesson): Black-headed Saltator.—Previously, breeding has been noted in this species in February, March, and April (Paynter, 1955a:284). A male taken on July 16 was in full breeding condition.
Specimens (3): ♂, 40895, testis 15 × 9 mm., 80.4 gm. (July 16), and ♀, 40896, 73.5 gm. (July 17), 7½ km. W Escárcega; ♂, 40894, 71.6 gm. (July 29), Pueblo Nuevo X-can.
Saltator coerulescens(Vieillot): Gray Saltator.—The only previous breeding record for this species is for April 26. Our one specimen, No. 40897, a juvenal male barely able to fly, taken on July 21 at Pisté, weighed 43.8 grams.
Richmondena cardinalis(Linnaeus): Cardinal.—The only record of breeding previously reported is of a male with enlarged testes taken on June 4 (Paynter, 1955a:287). Adult males with enlarged testes were obtained on July 11 and August 10, and three juveniles were taken southwest of Sisal on August 10, 16, and 18.
Specimens (7): ♂, 40903, testis 9 × 7 mm., 39.7 gm. (July 11), and ♀, 40904, 34.0 gm. (July 11), 5 km. S Champotón; ♂, 40898, testis 7 × 4 mm., 33.8 gm. (August 10), and ♀, 40899, juv. (rectrices and remiges ensheathed basally), 32.8 gm. (August 10), 13 km. WSW Sisal; ♂, 40900, fledgling, 18.4 gm. (August 18), 2 km. WSW Sisal; ♀, 40901, ovary granular, 37.4 gm., molting—1st primaries ensheathed (August 15), and ♂, 40902, imm., 34.0 gm. (August 16), 4 km. NNE Felipe Carrillo Puerto.
Cyanocompsa parellina(Bonaparte): Blue Bunting.—Specimens (2): ♂, 40906, imm. (July 15), and ♂, 40905, testis 10 × 7 mm., 15.2 mm. (July 15), 7½ km. W Escárcega.
Tiaris olivacea pusilla(Swainson): Yellow-faced Grassquit.—The only records of breeding, thus far, are by Paynter (1955a:291) for March 12 and June 14. A male (40907) taken 4 km. NNE Felipe Carrillo Puerto on August 14 had fully enlarged testes (8 × 5 mm.).
Tiaris olivacea intermedia(Ridgway): Yellow-faced Grassquit.—Although females taken on Isla Cozumel exhibited no reproductive activity, two males had moderately enlarged testes. These seem to be the first records of breeding in this subspecies, which is endemic to Isla Cozumel.
Specimens (5): ♂, 40908, testis 6 z 4 mm., 10.5 gm. (August 8), ♀, 40912, ovary inactive, 9.5 gm. (August 8), ♀, 40909, ovary inactive, 10.4 gm. (August 9), ♂, 40910, testis 5 × 3 mm., 11.5 gm., molting—1st primaries ensheathed (August 9), and ♂, 40911, 11.5 gm. (August 10), all from {2½}-{3½} km. N San Miguel, Isla Cozumel.
Sporophila torquiola morelleti(Bonaparte): White-collared Seedeater.—Breeding is known for this species in May and a male collected on September 2 was in breeding condition (Paynter, 1955a:293). Our records seem to be the first for the summer. Specimens taken in July and August were breeding.
Specimens (7): ♀, 40918, 9.2 gm. (July 8), 1 km. SW Puerto Real, Isla del Carmen; ♂, 40919, testis 7 × 6 mm., 8.2 gm. (July 15), 7½ km. W Escárcega; ♀, 40913, ovary inactive, 7.9 gm. (August 4), 4 km. WSW Puerto Juarez; ♂, 40914, testis minute, 7.8 gm. (August 14), ♀, 40915, ova to 6 mm. (August 15), ♀, 40917, ovary moderately active, 7.0 gm. (August 16), and ♂, 40916, testis 7 × 5 mm., 7.6 gm. (August 16), 4 km. NNE Felipe Carrillo Puerto.
Volatinia jacarina splendens(Vieillot): Blue-black Grassquit.—The only previous record of breeding is a male having slightly enlarged testes taken on June 1 (Paynter, 1955a:293). Our specimens showed various stages of reproductive activity when taken on July 10.
Specimens (6): ♂, 40926, 8.9 gm. (July 10), and ♂, 40925, testis 2 × 1 mm., 8.5 gm. (July 10), 1 km. S Puerto Real, Isla del Carmen; ♂, 40924, testis 4 × 2 mm. (July 10), ♂, 40922, testis 6 × 4 mm., 8.3 gm. (July 10), ♀, 40923, ova to 2 mm., 10.3 gm. (July 10), and ♂, 40921, 8.2 gm. (July 10), 5 km. S Champotón.
Arremonops rufivirgata verticalisRidgway: Olive Sparrow.—Apparently the only previous record of breeding was the laying female on June 14 reported by Paynter (1955a: 294). Males collected in July and August had enlarged testes; a juvenile, barely able to fly, was taken on August 14. Two specimens were beginning to molt.
Specimens (9): ♀, 40932, ova to 1 mm., 20.8 gm. (July 21), and ♂, 40933, testis 8 × 6 mm., 21.2 gm. (July 21), Pisté; ♀, 40930, ovary moderately active, 23.2 gm. (July 26), and ♂, 40931, imm., 22.7 gm. (July 26), 3½ km. N Pisté; ♂, 40934, testis 6 × 4 mm., 24.5 gm., molting—1st and 2nd primaries ensheathed (August 14), ♂, 40935, juv. (remiges and rectrices ensheathed basally), 17.7 gm. (August 14), ♀, 40936, imm., 25.0 gm (August 14), ♀, 40937, ovary granular, 22.6 gm., molting—2nd primaries ensheathed (August 15), and ♂, 40938, testis 7 × 5 mm. (August 15), 4 km. NNE Felipe Carrillo Puerto.
Arremonops chloronota chloronota(Salvin): Green-backed Sparrow.—Evidence presented by Monroe (1963) indicates thatA. chloronotaandA. conirostrisare not conspecific. Specimens collected in breeding condition in July seem to be the first breeding records of this species on the peninsula.
Specimens (7): ♀, 40942, ova to 3 mm., 29.6 gm. (July 11), 5 km. S Champotón; ♂, 40944, testis 10 × 6 mm., 27.0 gm. (July 14), ♂, 40943, testis 5 × 3 mm., 23.1 gm. (July 14), and ♂, 40945, testis 7 × 4 mm., 25.5 gm. (July 15), 5-{7½} km. W Escárcega; sex? 40939, 22.9 gm. (July 20), 6½ km. W Pisté; ♂, 40940, imm., 21.5 gm. (August 4), 4 km. WSW Puerto Juarez; ♀, 40941, 26.5 gm., extensive body molt, (August 15), 4 km. NNE Felipe Carrillo Puerto.