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 the _cenotes_ at Chichen-Itza; adults
with enlarged gonads and brood patches and juveniles were taken at
Piste as late as July 21.
Specimens (19): [Male], 40565, brood patch, 59.4 gm. (July 9),
[Male], 40564, testis 8 x 4 mm., brood patch, 68.0 gm. (July 9),
[Male], 40566, 74 gm. (July 9), [Female], 40567, juv. (July 9),
[Male], 40568, testis 5 x 3 mm., 68.3 gm. (July 10), [Male], 40578,
59.5 gm. (July 11), and [Female], 40577, ova to 2 mm., brood patch,
65.2 gm. (July 11), all from 5 km. S Champoton; [Male], 40560, 43.6
gm. (July 20), [Female], 40562, brood patch, 55 gm. (July 21), sex?
40561, 64 gm. (July 21), and [Female], 40563, juv. (July 22),
Piste. Eight nestlings (40569-76) that were taken from burrows at 5
km. S Champoton 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: _Philopterus_ sp., July 9.
_Momotus momota lessonii_ Lesson: Blue-crowned Motmot.--For convenience,
the specimens from 5 km. S Champoton are assigned to _M. m. lessonii_
on 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 for
_M. m. lessonii_. According to Paynter, there is a southward clinal
increase in size in this species between the smaller _M. m. exiguus_ in
the northern part of the peninsula and _M. m. lessonii_ in the extreme
southern part. A more extensive series of specimens from the vicinity
of Champoton probably would reveal a population intermediate in size
between the typical representatives of the two races.
Specimens (3): [Female], 40579, 105 gm. (July 10), [Female], 40581,
98.9 gm. (July 11), [Male], 40580, 102.5 gm. (July 11), 5 km. S
Champoton.
_Pteroglossus torquatus erythrozonus_ Ridgway: 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): [Male], 40586, testis 4 x 2 mm., 155 gm. (July 16),
7-1/2 km. W Escarcega; [Male], 40582, testis 10 x 5 mm., 169.1 gm.
(July 27), and [Female], 40583, ovary inactive, 137.3 gm. (July
29), Pueblo Nuevo X-can; [Female], 40584, ovary 10 x 6 mm., 169.5
gm. (August 15), and sex? 40585, 148.9 gm. (August 16), 4 km. NNE
Felipe Carrillo Puerto.
_Rhamphastos sulfuratus sulfuratus_ Lesson: Keel-billed Toucan.--This
species was especially common west of Escarcega, 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): [Female], 40589, 367.3 gm. (July 12), [Male], 40588,
testis 8 x 3 mm., 414.5 gm. (July 14), [Female], 40590, ovary 11
mm., 347.4 gm. (July 15), [Male], 40591, testis 5 x 3 mm., 371 gm.
(July 15), [Male], 40593, testis 6 x 3 mm., 422.2 gm. (July 16) and
[Male], 40592, 401.5 gm. (July 16), 6-7-1/2 km. W Escarcega;
[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 x 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
Escarcega.
_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 x 3 mm. (enlarged oviduct), 76.4 gm. (July 10), 1 km. S
Puerto Real, Isla del Carmen; [Male], 40599, testis 6 x 8 mm.,
101.3 gm. (July 10), and [Male], 40600, 86.0 gm. (July 11), 5 km. S
Champoton; [Male], 40603, testis 5 x 3 mm. (July 14), and [Female],
40604, ovary 6 x 4 mm. (ova to 1 mm.), brood patch (July 16), 7-1/2
km. W Escarcega; sex? 40596, molting, much visceral fat, 79.0 gm.
(July 22), Piste; [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): Yucatan 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 x 4 mm. (July 10); [Female],
40607, 39.5 gm. (July 10), 5 km. S Champoton; [Male], 40609, testis
inactive, 35.8 gm., moderate visceral fat (July 17), 1 km. N, 13
km. W Escarcega; [Female], 40606, ovary 6 x 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.
_Phloeoceastes guatemalensis guatemalensis_ (Hartlaub): Guatemalan
Ivory-billed Woodpecker.--Specimens (4): [Male], 40611, right testis 2
mm., left testis vestigial, 203.7 gm. (July 23), Piste; 40612, sex? 212
gm., (July 28), and [Female], 40613, 218.1 gm. (July 30), Pueblo Nuevo
X-can; [Female], 40614, 189.2 gm. (August 15), 4 km. NNE Felipe
Carrillo Puerto.
_Dendrocincla anabatina_ (Sclater): Tawny-winged Woodhewer.--Specimen
(1): [Male], 40615, testis 2 x 1 mm., 35.7 gm., molting--5th primaries
and middle pair of rectrices ensheathed (July 17), 1 km. N, 13 km. W
Escarcega.
_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): [Female], 40616, ovary 13 x 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): [Male], 40617, juv., 11.2 gm. (July 26), Piste;
[Female], 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): [Male], 40619, testis 5 x 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): [Male], 40621, testis 3 x 1 mm., 26.6 gm., molting--6th
primaries ensheathed, middle pair of rectrices are new (July 17), 1
km. N, 13 km. W Escarcega.
_Synallaxis erythrothorax_ Sclater: Rufous-breasted Spinetail.--Specimen
(1): [Male], 40622, imm. skull, 16.1 gm. (August 16), 4 km. NNE Felipe
Carrillo Puerto.
_Thamnophilus doliatus_ (Linnaeus): Barred Antshrike.--Specimen (1):
[Female], 40623, ovary 8 x 5 mm. (inactive), 26 gm. (August 14), 4 km.
NNE Felipe Carrillo Puerto.
_Formicarius analis_ (d'Orbigny and Lafresnaye): Black-chinned
Antthrush.--Specimen (1): [Male], 40624, 56.0 gm. (July 29), Pueblo
Nuevo X-can.
_Pachyramphus major itzensis_ Nelson: 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): [Male], 40625, testis 9 x 5 mm., 22.1 gm. (July 21),
Piste.
_Platypsaris aglaiae_ (Lafresnaye): Rose-throated Becard.--All
specimens have extensively worn plumage.
Specimens (3): [Male], 40628, 33.5 gm. (July 10), 5 km. S
Champoton; [Female], 40626, ovary 6 x 3 mm., brood patch, 34.0 gm.
(July 20), [Female], 40627, ovary inactive, 33.9 gm. (July 26);
3-1/2 km. N and 6-1/2 km. W Piste.
_Tityra semifasciata personata_ Jardine 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 7-1/2 km. W Escarcega on July 15, and a juvenile was taken.
Gonads of males were in full breeding condition.
Specimens (5): [Male], 40630, testis 13 x 6 mm., 81.3 gm. (July
14), sex? 40631, juv., 55.5 gm. (July 15), [Male], 40632, testis 9
x 5 mm., 73 gm., molting--1st and 2nd primaries ensheathed (July
15), and [Female], 40633, 84.7 gm. (July 16), 7-1/2 km. W
Escarcega; [Female], 40629, ova to 1 mm., 80.0 gm. (July 23),
Piste.
_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 Piste, on
July 21.
Specimens (2): [Female], 40635, 51.8 gm. (July 15), 7-1/2 km. W
Escarcega; [Male], 40634, testis 6 mm., 51 gm., molting--6th
primaries ensheathed (July 21), Piste.
_Pipra mentalis mentalis_ Sclater: Red-capped Manakin.--The specimens
here reported seem to be the first from the peninsula in which
reproductive activity has been recorded.
Specimens (2): [Male], 40637, testis 5 x 3 mm., 14.0 gm. (July 29),
Pueblo Nuevo X-can; [Male], 40636, testis 5 x 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): [Female], 40638, juv., 12.1 gm. (August 7), 1-1/2
mi. S Sisal; [Female], 40640, ovary inactive, 14.1 gm.,
molting--6th primaries ensheathed (August 10), [Female], 40641,
ovary inactive, 13.9 gm., molting--7th primaries ensheathed (August
10), and [Male], 40642, testis 2 mm., 14.6 gm., molting--5th
primaries ensheathed (August 10), 13 km. WSW Sisal; [Female],
40639, testis 1 mm., 14.0 gm., molting--7th primaries ensheathed
(August 18), 2 km. SW Sisal.
_Tyrannus melancholicus chloronotus_ Berlepsch: Tropical Kingbird.--Most
specimens were molting. A male and two females from Piste 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 Piste. There seems to be no other
breeding records from the peninsula.
Specimens (10): [Female], 40650, 42 gm., (July 10), 5 km. S
Champoton; [Female], 40752, ovary inactive, 43.4 gm., molting--4th
primaries ensheathed (July 14), and [Male], 40651, imm., 42.5 gm.
(July 15), 6-7-1/2/# km. W Escarcega; [Female], 40645, ovary
slightly enlarged (8 x 3 mm.), 47.5 gm. (July 21), [Female], 40643,
ova to 1 mm., 39.3 gm. (July 21), [Male], 40644, testis 10 x 7 mm.,
43.1 gm., starting to molt--1st primaries ensheathed (July 21), and
[Female], 40646, imm., (July 26), Piste; [Female], 40648, ova to 1
mm., 37.4 gm. (July 29), Pueblo Nuevo X-can; [Male], 40647, imm.,
38.4 gm. (August 14), and [Female], 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 luteiventris_ Sclater: 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): [Female], 40655, 44.5 gm. (July 10), 5 km. S
Champoton; [Female], 40656, ovary slightly enlarged (8 x 4 mm.),
47.0 gm. (July 15), 7-1/2 km. W Escarcega; [Female], 40654, testis
10 x 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): [Female], 40658, 57.6 gm. (July 11), 5 km. S
Champoton; [Female], 40657, ovary 10 x 5 mm., 59.8 gm. (July 25),
Cenote Seco, 2 km. E Chichen-Itza.
_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 Escarcega had enlarged (probably regressing)
testes and indicates breeding later than May.
Specimens (3): [Male], 40660, testis 6 x 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 Escarcega; [Male], 40659, imm., testis 2 x 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): [Female], 40663, ova to 1 mm., 50.7 gm. (July 9),
and [Male], 40664, right testis 12 mm., 65.0 gm., body feathers in
early stages of molt (July 9), 5 km. S Champoton; [Male], 40665,
testis 5 mm., 61.9 gm., molting--middle pair of rectrices are new,
6th primaries ensheathed (July 15), 7-1/2 km. W Escarcega; sex?
40662, 59.5 gm. (August 14), 4 km. NNE Felipe Carrillo Puerto.
Mallophaga: _Philopterus_ sp.
_Myiarchus tyrannulus cooperi_ Baird: Wied Flycatcher.--This species
was especially common among the coco palms on Isla del Carmen and Isla
Cozumel.
Specimens (5): [Male], 40667, 36.7 gm. (July 8), [Male], 40668,
36.6 gm. (July 8), sex? 40669, 39.4 gm. (July 8), and [Female],
40670, 37.3 gm. (July 8), all from 1 km. SW Puerto Real, Isla del
Carmen; [Female], 40666, ovary inactive, 34.9 gm. (August 10), 3
km. N San Miguel, Isla Cozumel.
_Myiarchus tuberculifer platyrhynchus_ Ridgway: 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): [Female], 40673, ova to 5 mm. (July 10), and
[Female], 40674, ovary 7 x 3 mm. (ova to 1 mm.) (July 11), 5 km. SW
Champoton; [Female], 40745, ovary inactive, 17.5 gm., starting to
molt--1st, 2nd, and 3rd primaries ensheathed (July 16), 7-1/2 km. W
Escarcega; [Female], 40671, imm., 16.1 gm. (July 20) Cenote Seco, 2
km. E Chichen-Itza; [Male], 40746, 18.2 gm. (July 22), Piste;
[Female], 40672, ovary inactive, 17.7 gm., molting--5th and 6th
primaries and 1st secondaries ensheathed (August 15), 4 km. NNE
Felipe Carrillo Puerto; [Male], 40675, left testis 13 mm., right
testis 10 mm., 17.5 gm. (August 8), 3-1/2 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): [Male], 40676 testis 6 x 3 mm., 11.5 gm., starting
to molt--1st and 2nd primaries ensheathed (July 21), 6-1/2 km. W
Piste; [Male], 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): [Female], 40683, juv., 14.0 gm. (July 21), [Male],
40684, juv. (remiges and rectrices ensheathed basally), 14.0 gm.
(July 21), and [Male], 40682, testis 8 x 4 mm., 13.7 gm. (July 26),
Piste and 3-1/2 km. N Piste; [Male], 40685, testis 7 x 4 mm., 15.3
gm., molting--1st and 2nd primaries ensheathed (July 28), and
[Female], 40686, ovary inactive (July 28), Pueblo Nuevo X-can;
[Male], 40687, imm., 16.0 gm. (August 15), 4 km. NNE Felipe
Carrillo Puerto. Mallophaga: _Philopterus_ sp. July 28; _Myrsidea_
sp. 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): [Male], 40688, testis 7 x 4 mm., 13.1 gm. (July 17),
1 km. N, 13 km. W Escarcega.
_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): [Female], 40723, ovary inactive, 48.6 gm. (August
14), [Female], 40724, 51.8 gm. (August 17), and [Female], 40725,
imm. skull, 52.1 gm. (August 17), 4 km. NNE Felipe Carrillo Puerto.
_Petrochelidon fulva citata_ Van Tyne: Cave Swallow.--Throughout our
stay at Piste, large numbers of Cave Swallows were seen flying in and
out of the small opening of a well-like _cenote_ in 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 the
_cenote_ although 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 Piste, July 21-25: [Male], 40693, testis 6 x 3 mm., 18.4
gm.; [Male], 40696, 16.4 gm.; [Female], 40697, 18.2 gm.; [Male],
40695, 15.0 gm.; [Female], 40690, ovary inactive, 18.4 gm.,
molting--2nd primaries ensheathed; [Male], 40692, testis 5 x 3 mm.,
17.9 gm.; [Female], 40698, 18.3 gm.; [Female], 40702, ovary 7 x 3
mm., 18.9 gm.; [Female], 40703, ovary 6 x 3 mm., 17.5 gm.; [Male],
40713, testis 3 mm., 18.4 gm.; [Female], 40704, 16.5 gm.; [Male],
40705, 20.3 gm.; [Male], 40699, testis 2 mm., 18.6 gm.,
molting--2nd primaries ensheathed; [Female], 40700, ovary 5 x 3
mm., 18.5 gm., molting--1st primaries ensheathed; [Female], 40701,
ovary 5 x 3 mm., 16.5 gm., molting--1st primaries ensheathed;
[Male], 40707, testis 7 x 5 mm., 19.9; [Male], 40708, testis 4 x 3
mm., 18.4 gm.; [Female], 40709, ovary 4 x 3 mm., 18.0 gm.; sex?
40711, 18.3 gm., molting--1st and 2nd primaries ensheathed.
Additional specimens are: [Female], 40718, 16.5 gm., molting--3rd
primaries ensheathed (August 16), and [Female], 40719, 18.5 gm.,
molting 1st primaries ensheathed (August 16), 4 km. NNE Felipe
Carrillo Puerto; [Male], 40689, testis 1 mm., 16.2 gm.,
molting--2nd primaries ensheathed (August 10), 13 km. WSW Sisal.
Mallophaga: _Philopterus excisus_, July 21; _Myrsidea_ sp. July 21
and 25.
_Stelgidopteryx ruficollis_ Audubon: Rough-winged Swallow.--Previous
records indicate that three subspecies of this species occur on the
Yucatan 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 to
_S. 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 Piste as _S. r. stuarti_; one specimen from Puerto Juarez
also is an immature and is nearly identical to those from Piste. Two
adults from Piste (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 for _S. r. stuarti_ to 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 of _S. r. ridgwayi_.
Except for the immature individual from 5 km. WSW Puerto Juarez, all
specimens were taken in mist nets over the _cenote_ at Piste where
_Petrochelidon fulva_ also was obtained.
Specimens (7): [Male], 40694, imm., 16.2 gm., [Female], 40691,
ovary inactive, 16.4 gm., molting--general body molt, 5th primaries
and middle pair of rectrices ensheathed, [Female], 40712, imm.,
14.5 gm., [Female], 40706, 14.8 gm., [Male], 40715, 16.4 gm.,
[Male], 40710, 18.5 gm., molting--general body molt, 1st primaries
and middle pair of rectrices ensheathed, all from Piste, July 21
and 25; [Male], 40720, imm., 15.5 gm. (August 1), 5 km. WSW Puerto
Juarez.
_Hirundo rustica erythrogaster_ Boddaert: Barn Swallow.--Specimen (1):
[Female], 40721, imm., 7.3 gm. (August 18), apparently an early
migrant, 2 km. WSW Sisal.
_Iridoprocne albilinea_ (Lawrence): Mangrove Swallow.--Specimen (1):
[Female], 40722, imm. (July 7), Puerto Real, Isla del Carmen.
_Cissilopha yucatanica_ (Dubois): Yucatan 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): [Male], 40726, left testis 9 x 7 mm., right testis 4
x 2 mm., brood patch, 122.3 gm., molting--1st and 2nd primaries
ensheathed (July 10), 5 km. S Champoton; [Male], 40727, testis 5 x
3 mm., brood patch, 125.6 gm., molting--1st and 2nd primaries
ensheathed (July 11), 5 km. SW Champoton; [Female], 40728, 109.8
gm. (July 13), and sex? 40729, 109.5 gm. (July 15), 7-1/2 km. W
Escarcega; [Female], 40730, imm., 110.3 gm. (July 21), Piste;
[Female], 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): [Male], 40740, testis 5 x 3 mm., 81.2 gm. (July 16),
7-1/2 km. W Escarcega; [Female], 40739, juv., 62.3 gm. (July 21),
[Male], 40737, 64.5 gm. (July 21), and [Female], 40738, 64.1 gm.
(July 21), Piste.
_Psilorhinus morio_ (Wagler): Brown Jay.--Specimens (3): [Female],
40742, 203.5 gm. (July 13), [Male], 40743, juv., 170 gm. (July 14),
7-1/2 km. W Escarcega; [Male], 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 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): [Male], 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.