Thamnophilidae -

Antbirds are in an insectivorous family that includes many forest , but some are found higher up in the subcanopy while others are terrestrial. Most are well suited to living in tropical habitats, including forest interior and second growth, as well as various specialized microhabitats like gaps and vine tangles. The most unifying feature of the family is their bill shape which has a terminal hook and a pinched base. Many species are dimorphic in with males being grayish to black with variably white wingbars, wing spots, tail spots, concealed intrascapular patch, or other black-and- white patterning. The females are often brownish, -, or tawny, often similar in pattern to the male, except that blacks are replaced by contrasting with brighter orange or buffy barring. Although sexual dichromatism is common in the family, the obligate -followers either minimize this (i.e. ) or are not dichromatic (e.g. ). The most common molt strategy of the family is the Complex Basic Strategy. The first preformative molt can be partial to complete and may be related to the amount of time self-sufficient young remain within their parent’s . Species that follow their parents for some time after fledging often retain a female-like plumage through a partial first preformative molt such that young can be distinguished by their distinct molt limits. However, juveniles of species that probably disperse away from their parents at an early age appear to have formative similar to that of the adult plumage or have a complete first prebasic molt. Delayed plumage maturation is at best minimal for some species at the BDFFP; the definitive plumage is achieved no later than upon completion of the 2nd prebasic molt, but in some species the definitive plumage is achieved upon completion of the 1st preformative molt. The skull completes in adults, probably at about 6 months of age, but more study is needed to pin down the exact timing. Both sexes share in incubation and often develop brood patches, but are usually more developed in females. In most species, the timing of breeding often corresponds with the dry season, but there are exceptions as well as some asynchrony in these populations with some individuals breeding at any time of the year, sometimes when less than 1 year of age (before definitive plumage is achieved). Molt often occurs after the breeding season, but is again highly asynchronous in these populations. Molt-breeding overlap is frequent.

# species at BDFFP: 28 # species netted: 22 # primaries: 10 # secondaries: 9 # rectrices: 12 lineatus lineatus – Band size: F-G

# Individuals Captured: 23 Similar Species: Fine black and white barring throughout body of ♂ is unique at PDBFF. ♀ most like ♀ of viridis, but smaller with barred black and white back and wings.

Measurements: 100 Wing ♂ 70.5-74.0 (72.4 ± 1.3; n13) ♀ 70.0-78.0 (73.3 ± 2.8; n10) 80 Tail ♂ 65.0-72.0 (68.8 ± 2.3; n12) 60 ♀ 66.0-79.0 (71.4 ± 4.1; n8)

Mass ♂ 29.0-39.0 (35.3 ± 2.7; n13) 40 ♀ 30.0-40.0 (33.5 ± 2.9; n9) Bill ♂ 13.9 (n1) 20 ♀ 14.5 (n1) 0 Tarsus ♂ 29.5 (n1) % birdswith molt (closed circles)(open or bp circles) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 28.9 (n1) Molt, n =110331244123 Skull: Probably completes (n2), but no other Bp, n =000001030010 information available. Brood Patch: Observed in 3 ♀♀ in Aug and probably possible in ♂♂ as they share in incubation, which may occur at least between Jul and Nov (HBW). Molt-breeding overlap is 0.0% (n3). Molt: Little information available, but probably Complex Basic Strategy. Ryder and Wolfe (2009) state that PF1 is incomplete or eccentric, but we suspect that PF1 of C. l. intermedius can complete based on 28 specimens at LSU and may also complete in C. l. lineatus. PBs are complete and the PA is apparently absent. Based on 1-4 captures per month (none in Mar) at the BDFFP, there appears to be two periods when complete wing molt occurs: Apr to May and Sep to Nov. No birds were observed in molt between Dec and Feb (n5) and from Jun to Aug (n7). Individual birds may have very flexible schedules and may molt during both periods of molt. Three birds have been recaptured; all were in PB (i.e. wing feathers were molting) upon initial capture (2 in May and 1 in Dec) and all had evidence of tail molt upon recapture 6-7 months later. Whether this is evidence of a new molt is unclear; it is possible that the replacement of lost tail feathers was misclassified as molt or that the annual timing of molt is highly variable. Age/Sex: BASIC I: ♀≠♂ (?) ♀ - May have black barring on rusty-brown crown as in C. l. intermedius. Iris may be brown. ♂ - Perhaps like Basic I ♀, but with narrower markings on pp and ss. Iris may be brown.

FORMATIVE I: ♀≠♂ ♀ - This may be the definitive plumage, but is unknown. Some birds may have molt limits among the remiges in which case the B2 would be the definitive plumage. Iris may be dull or orange. ♂ - This may be the definitive plumage. Look for molt limits among the remiges in some individuals. According to HBW, “subadult” ♂♂ have broader white barring on crown and body, but it is unclear if this refers to the B1or F1. Cymbilaimus lineatus lineatus – Fasciated Antshrike

BASIC II: ♀≠♂ ♀ - The definitive plumage. The underparts are buffy- white and faintly barred black. The upperparts are boldly barred black and - white. The crown is solid rusty-brown. Iris is bright red.

♂ - The definitive plumage. Has relatively narrow white barring on crown and body with narrow white barring on the outer webbing of remiges (B). Iris is bright red (C). Frederickena viridis (no subspecies) – Black-throated Antshrike Band size: H

# Individuals Captured: 110 Similar Species: ♂ most like rufifrons, but larger and lacks white-tipped wing covs. ♀ most like Cymbilaimus lineatus, but larger with solid rusty-brown wings and upperparts.

Measurements: 100 Wing ♂ 88.0-98.0 (92.0 ± 2.3; n44) ♀ 86.0-98.0 (91.9 ± 2.7; n44) 80 Tail ♂ 67.0-86.0 (75.8 ± 3.7; n42) 60 ♀ 65.0-84.0 (75.8 ± 3.9; n38)

Mass ♂ 58.7-77.5 (67.1 ± 4.1; n46) 40 ♀ 61.0-77.0 (67.4 ± 3.9; n51) Bill ♂ 15.3-16.0 (15.7 ± 0.4; n3) 20 ♀ 15.9-16.6 (16.3 ± 0.5; n2) % with molt (solid lines) or bp (dotted lines) (dotted bp or lines) (solid molt with bird % 0 Tarsus ♂ 38.6-41.6 (39.7 ± 1.7; n3) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 38.8-39.0 (38.9 ± 0.1; n2) Molt, n =2 7 111315211616128 238 Skull: Completes (n9), possibly during the Bp, n =000022612161 PF1, but more study is needed. Brood Patch: Only ♀♀ have been observed with BPs (n3), between Jun and Nov, but ♂♂ also probably develop BPs. Molt-breeding overlap is 0.0% (n3). Molt: Complex Basic Strategy: PF1 complete, PBs complete. Molt peaks (>70%) in Dec and Jan and is least frequent (<15%) in Aug and Sep. Age/Sex:

BASIC I: ♀=♂ Like the definitive ♀, but the iris is dull brown and the maxilla and especially mandible has extensive yellow. The remiges are unmarked brown and the chest is barred black gray and white and is less boldly patterned than in definitive ♀♀. 1st PREFORMATIVE MOLT: ♀≠♂ ♀ - Can be similar to definitive ♀♀, but the dull brown iris and yellowish bill are retained into the PF1 and are useful characteristics to separate PF1 ♀♀ from definitive ♀♀ when early in molt. The iris changes to red and the bill turns black by the completion of PF1 and should not be used to age birds in later stages of molt. ♂ - Mixed gray and brown. Iris and bill features as in PF1 ♀♀. Frederickena viridis (no subspecies) – Black-throated Antshrike

FORMATIVE I: ♀≠♂ ♀ - The definitive plumage. Has finely barred black and white underparts, tail, and face. The crown, back, and wings are solid rusty-brown. Iris is reddish orange to red. Bill is all black.

♂ - The definitive plumage. Unmarked charcoal gray underparts, back, and wing with faintly barred gray tail. Iris is red. Bill is all black.

Note: There is variation in the strength of barring on the rects that may be age/sex related, but more study is needed. murinus murinus – Mouse-colored Antshrike Band size: E

# Individuals Captured: 228 Similar Species: ♂ from other medium-sized, all-gray antbirds (e.g. caesius) by grayish iris, brownish wings, and faint white tips to wing covs. ♀ from other brown antbirds by contrastingly brighter rufous crown, grayish iris, and overall lack of pattern. Measurements: 80 Wing ♂ 54.0-65.0 (60.3 ± 1.8; n101) ♀ 54.0-64.0 (59.7 ± 1.9; n77) Tail ♂ 47.0-61.0 (52.2 ± 2.6; n98) 60 ♀ 49.0-59.0 (52.9 ± 2.1; n71) Mass ♂ 15.0-22.0 (17.5 ± 1.1; n117) 40 ♀ 15.0-22.0 (18.0 ± 1.6; n86) Bill ♂ 10.2-12.9 (11.5 ± 0.8; n11) 20 ♀ 10.7-12.1 (11.4 ± 0.5; n10)

Tarsus ♂ 20.0-23.2 (21.3 ± 0.9; n11) (solidlines) birdswith molt or bp (dotted % 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 20.9-23.0 (22.0 ± 0.7; n11) Molt, n = 13 8 15 19 18 21 20 38 26 41 32 16 Skull: Completes (n24) during F1. Bp, n =00012361441867 Brood Patch: ♂♂ (n2) and ♀♀ (n7) develop BPs from Jul to Oct. Molt-breeding overlap is 0.0% (n13). Molt: Complex Basic Strategy: PF1 partial, PBs complete. PF1 includes body feathers and usually all wing covs except for pp covs. The alula is not replaced, but 1 or 2 alula covs are (always?). The proportion of individuals in molt is lowest in Jul (0%), but otherwise may occur year-round. Age/Sex:

BASIC I: ♀=♂ (?) Like definitive ♀ (at least in T. m. canipennis), but duller and darker. Pp covs are dull dark brown with paler dull brown edging. The outer webbing of p9 and p10 appears to be consistently broader than in B2, but more study is needed. The iris may be dull brownish-gray to gray. The remiges of ♂♂ may be grayish-while ♀♀ remiges may be brown.

FORMATIVE I: ♀≠♂ ♀ - Very similar to the definitive ♀ and brownish overall, but look for molt limits between the pp and gr covs as well as between the retained alula and replaced alula covs. The outer webbings of p9 and p10 are broad as these feathers are retained from the B1. The iris is gray or brownish-gray

PF1 molt; pp6-10 and ss2-6 still retained Thamnophilus murinus murinus – Mouse-colored Antshrike

FORMATIVE I: ♀≠♂ ♂ - Grayish overall with brown wings. The replaced med and gr covs are dull brownish- gray often with small buffy tips. The retained pp covs are brown with no edging or pale tips resulting in molt limits between the pp covs and gr covs. The alula is retained, while 1 or 2 of the alula covs are replaced. The retained pp and ss are dull brown. The central belly is usually buffy-gray. The outer webbings of p9 and p10 are broad. The iris is gray.

BASIC II: ♀≠♂ ♀ - The definitive plumage. Without molt limits; the med, gr, and pp covs are uniform in age. The outer webbings of p9 and p10 are distinctly narrow. All brown with contrastingly brighter crown. Pp covs are rich brown with bright brown edging. Pp and ss are rich brown. The iris is gray or brownish-gray.

♂ - The definitive plumage. Without molt limits; the med, gr, and pp covs are uniform in age. The outer webbings of p9 and p10 are distinctly narrow. Grayish overall with brownish-edged gray pp and ss. Med and gr covs are bright -gray with small a white spot at the tip. Iris is gray. Thamnophilus punctatus punctatus – Northern Slaty-Antshrike Band size: E

# Individuals Captured: 2 Similar Species: Size and bold white spots on outer webbing of to less, med, and gr covs distinctive for both ♂♂ and ♀♀. Also note crown patches in both sexes. Measurements: Wing ♂ unknown ♀ 63.0-66.5 (64.8 ± 2.47; n2) Tail ♂ unknown ♀ 53.0-55.0 (54.0 ± 1.41; n2) Mass ♂ unknown ♀ 16.4-18.7 (17.6 ± 1.63; n2) Skull: Probably completes, but no information available. Brood Patch: No information available. Definitive ♀♀ of T. murinus (left) and T. punctatus (right) Molt: Presumably Complex Basic Strategy, but little information from the BDFFP available. A definitive ♀ without molt was captured in Jul, but wing molt was nearly complete when she was recaptured in Dec. Age/Sex:

BASIC I: ♀?♂ No information available.

FORMATIVE I: ♀≠♂ No information available for separating from the definitive plumage.

BASIC II: ♀≠♂ ♀ - Probably the definitive plumage. Similar to ♂ in wing and tail pattern, but brown instead and brown overall with bright rufous crown. White spotting on the covs are mostly on the outer web and are bordered by black, which in blends into an otherwise brown feather. The iris is reddish-brown.

♂ - Probably the definitive plumage. Gray overall with contrasting black crown, wing and tail. Wing and tail also with bold white spots. Thamnomanes ardesiacus obidensis – Dusky-throated Antshrike Band size: E

# Individuals Captured: 903 Similar Species: Both sexes separated from other antbirds by lacking wing markings and measurements. ♂ from T. caesius by black throat, shorter tail (with minimal overlap), and presence of a narrow eyering. ♀ from T. caesius by duller orange underparts and shorter tail. T. caesius also has brighter and larger white interscapular patch in both sexes. Intrascapular patch in definitive-♀ Measurements: 60 T. ardesiacus (left) and T. caesius (right). Wing ♂ 66.0-78.0 (72.3 ± 2.0; n352) 50 ♀ 66.0-78.0 (72.1 ± 2.1; n245) Tail ♂ 46.0-58.0 (51.4 ± 2.0; n325) 40

♀ 47.0-58.5 (52.2 ± 1.8; n241) 30 Mass ♂ 13.0-22.5 (18.1 ± 1.3; n457) 20 ♀ 15.0-23.0 (18.1 ± 1.4; n318) Bill ♂ 10.0-11.9 (11.1 ± 0.4; n31) 10

♀ 10.4-12.1 (11.3 ± 0.4; n17) birds% with molt (solid line) or bp (dotted line) 0 Tarsus ♂ 20.0-22.5 (21.4 ± 0.6; n31) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 20.3-23.0 (21.6 ± 0.8; n17) Molt, n = 85 63 104 123 136 128 225 200 155 159 169 88 Skull: Completes (n43) during F1. Bp, n = 0 0 3 8 7 20 61 36 28 24 39 7 Brood Patch: Observed from Jul to Dec(-Feb?) and although they are more evident in ♀♀, they also develop in ♂♂. Although not yet observed in T. ardesiacus, one F1 T. caesius ♀ and two ♀♀ starting PB2 had BPs, so the presence of a BP should not be used to justify aging as adult. Molt-breeding overlap is 25.0% (n24). Molt: Complex Basic Strategy: PF1 partial(-incomplete), PBs complete. PF1 includes the less covs, and 0 to all gr covs (usually inner 3), and rarely 1 to 3 terts and up to several rects. The frequency of molt peaks (>50%) in Dec and Jan and is least frequent (<15%) in Jul. Age/Sex: BASIC I: ♀≠♂ ♀ - Generally mottled brown with little gray. Wing covs and remiges are edged chestnut. Rects are distinctly pointed and brown. Iris is brownish-black.

♂ - Mottled brown and gray with more gray than brown. Rects, some body feathers, and flight feathers are brownish-gray. Rects are distinctly pointed. The iris is brownish-black. Thamnomanes ardesiacus obidensis – Dusky-throated Antshrike

FORMATIVE I: ♀≠♂ ♀ - Very similar to B2 and brownish overall, but look for molt limits among the gr covs or rarely between the gr covs and pp covs and/or among the ss with bright the inner covs contrasting with duller outer covs. Rects are B1-like and distinctly pointed, but occasionally some rects are replaced and more rounded. The iris is dark brown.

♂ - Similar to B2 and grayish overall, including black throat, but look for molt limits among the gr covs or rarely between the gr covs and pp covs and/or among the ss with bright the inner covs contrasting with duller outer covs. Rects are B1-like and distinctly pointed, but occasionally some rects are replaced and more rounded. The iris is dark brown. Thamnomanes ardesiacus obidensis – Dusky-throated Antshrike

BASIC II: ♀≠♂ ♀ - The definitive plumage. -brown overall, paler on the underparts with an faint grayish-white concealed intrascapular patch. Lacks molt limits and has uniformly aged brown wing covs lacking chestnut edging and washed olive when fresh. Rects are slightly pointed or distinctly rounded. The iris is dark brown.

♂ - The definitive plumage. Gray overall with grayish-white concealed intrascapular patch and variably small whitish tips on the rects. Wing covs and remiges are uniformly bright gray without molt limits. Rects are slightly pointed or distinctly rounded. The iris is dark brown. Thamnomanes caesius glaucus – Cinerous Antshrike Band size: E

# Individuals Captured: 962

Similar Species: See T. ardesiacus. 50 Measurements: Wing ♂ 66.0-77.0 (71.4 ± 1.9; n349) 40 ♀ 66.0-76.0 (70.9 ± 1.8; n295) 30 Tail ♂ 55.0-70.5 (63.2 ± 2.7; n326)

♀ 56.0-71.0 (63.6 ± 2.7; n270) 20 Mass ♂ 14.5-21.5 (17.6 ± 1.2; n462) ♀ 14.0-21.5 (17.5 ± 1.3; n372) 10 Bill ♂ 10.0-13.2 (11.0 ± 0.7; n26) % birds with molt (solid line) or bp (dotted line) bp (dotted line) or (solid with molt % birds 0 ♀ 9.4-11.4 (10.5 ± 0.4; n24) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Tarsus ♂ 18.7-20.8 (19.6 ± 0.6; n26) Molt, n = 56 48 72 97 80 91 136 158 118 151 132 53 ♀ 18.9-21.2 (19.8 ± 0.6; n24) Bp, n = 0 0 3 1 10 19 27 42 25 38 28 4 Skull: Completes (n44) during F1. Brood Patch: Observed during the dry season from Jul to Nov(-Dec?). More evident in ♀♀, but develops in ♂♂. One T. caesius ♀ in F1 and two ♀♀ beginning PB2 had BPs, so the presence of a BP should not be used to justify aging as adult. Molt-breeding overlap 17.6% (n34). Molt: Complex Basic Strategy: PF1 partial(-incomplete), PBs complete. PB1 includes the less covs, med covs, and 0 to all gr covs (usually inner 3), and rarely some or all of the terts. Can occur at any time year, peaking (>45%) in Mar and is least frequent (<25%) in Jun to Aug. Age/Sex:

BASIC I: ♀≠♂ ♀ - Generally mottled brown with little gray. Rects are slightly pointed. The iris is brownish-black. ♂ - Generally mottled brown and gray and has grayish-brown remiges. Rects are slightly pointed (see T. ardesiacus) and mostly gray. The iris is brownish-black.

FORMATIVE I: ♀≠♂ ♀ - Like B2 and brownish overall, but look for molt limits among the gr covs or occasionally between the gr covs and pp covs and/or among the terts where brighter replaced inner covs contrast with the duller retained outer covs. Rects are B1- like and distinctly pointed, but occasionally some rects are replaced and more rounded. Thamnomanes caesius glaucus – Cinerous Antshrike

FORMATIVE I: ♀≠♂ ♂ - Like B2 and gray overall, but look for molt limits among the gr covs or occasionally between the gr covs and pp covs and/or among the ss where brighter replaced inner covs contrast with the duller retained outer covs. Rects are B1-like and distinctly pointed, but occasionally some rects are replaced and more rounded.

BASIC II: ♀≠♂ ♀ - The definitive plumage. Ochre-brown overall, deep ochre-orange on the underparts with white concealed intrascapular patch. Without molt limits and has uniformly aged wing covs. Wing covs and flight feathers are brown with a hint of olive. Rects are slightly pointed or distinctly rounded. The iris is dark brown.

♂ - The definitive plumage. Gray overall with white concealed intrascapular patch, and variably small whitish points on the rects. Without molt limits and has uniformly aged wing covs. Wing covs and remiges are bright gray. Rects are slightly pointed or distinctly rounded. The iris is dark brown. Epinecrophylla gutturalis (no subspecies) – Brown-bellied Antwren Band size: D

# Individuals Captured: 631 Similar Species: ♂ plumage with black and white checkered throat distinctive. ♀most similar to menetriesii, but with longer tail (Table X), wing covs with pale dots (not scaled), and pale (not dark) iris. Also compare more yellow ochraceiceps, which has a dark eye, squared tail, and tawny lores. 40 Measurements: Wing ♂ 45.5-53.0 (49.8 ± 1.4; n200) ♀ 46.0-54.5 (49.5 ± 1.4; n179) 30 Tail ♂ 32.0-46.0 (40.2 ± 2.0; n195) ♀ 32.0-47.0 (40.0 ± 2.4; n165) 20 Mass ♂ 6.8-11.0 (8.6 ± 0.7; n278) ♀ 7.0-11.0 (8.9 ± 0.9; n228) 10 Bill ♂ 7.5-9.5 (8.6 ± 0.6; n12)

♀ 7.9-9.4 (8.6 ± 0.5; n15) line) or bp (dotted line) (solid molt with birds % 0 Tarsus ♂ 16.8-18.7 (17.6 ± 0.6; n11) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Molt, n = 56 48 72 97 80 91 136 158 118 151 132 53 ♀ 16.2-18.2 (17.5 ± 0.6; n15) Bp, n = 0 0 3 1 10 19 27 42 25 38 28 4 Skull: Nearly (>90%) or completely ossifies, probably during F1. Brood Patch: Observed between Jul and Nov(-Dec?) in both sexes. Molt-breeding overlap is 16.7% (n18). Molt: Complex Basic Strategy: PF1 partial, PBs complete. PF1 includes body feathers, all less covs, all med covs, and usually no gr covs (but occasionally inner 1 or 2) and no flight feathers. Molt frequency peaks (>35%) in Mar and is least frequent (<20%) from Jun to Sep. Age/Sex: BASIC I: ♀=♂ (?) Has rich chestnut brown on upperparts, weakly defined buffy spotting in covs (although beware of definitive ♀♀ with similar spotting) and pp covs faintly tipped buffy to pale brown with less contrast and weaker edging contrast than the similar, but brighter, pattern of definitive adults. Gr covs are brown at the base without an olive wash. It is possible that ♀♀ have browner throats than ♂♂, but more study is needed. The iris is dark gray, but quickly changes to tawny brown then creamy white, often after PF1 commences. Epinecrophylla gutturalis (no subspecies) – Brown-bellied Antwren

FORMATIVE I: ♀≠♂ ♀ - Similar to B2 with a brown throat, but note molt limits between replaced med covs and retained gr covs and pp covs (or occasionally some inner gr covs are replaced). These can be very difficult to see and examining skull pneumatization should help identify younger birds F1, but the skull ossifies before PB2 begins. The iris is pale brown.

♂ - Similar to B2 with a checked black and white throat, but note molt limits between replaced med covs and retained gr covs and pp covs (or occasionally some inner covs are replaced). The iris is creamy white.

BASIC II: ♀≠♂ ♀ - The definitive plumage. The throat is plain brown and concolor with the underparts. The buff tips on the med covs and gr covs have a well- defined border and lacks molt limits. Pp covs are brown with distinct buff tip that fades with wear. The iris is pale brown. Epinecrophylla gutturalis (no subspecies) – Brown-bellied Antwren

BASIC II: ♀≠♂ ♂ - The definitive plumage. The throat is checkered black and white and underparts are gray. Lacking molt limits, the wing covs have a black border along the proximal end of the buffy-white tips and show greater contrast between the brown base and buff tip than ♀. Pp covs are brown with distinct buff tip that fades with wear. The iris is creamy white.

Table X. Antwren measurements (range) of the BDFFP. Data for ♂♂ and ♀♀ are pooled. See species accounts for averages and standard deviations. Species Wing Tail Mass Bill Tarsus Epinecrophylla gutturalis 45.5 – 54.5 32.0 – 47.0 6.8 – 11.0 7.5 – 9.5 16.2 – 18.7 Myrmotherula guttata 46.0 – 54.0 19.0 – 30.0 7.5 – 13.0 7.9 – 8.8 17.3 – 22.6 Myrmotherula axillaris 46.0 – 56.0 31.0 – 44.0 6.0 – 9.5 7.3 – 9.6 16.4 – 18.0 Myrmotherula longipennis 51.0 – 63.0 29.0 – 41.0 6.5 – 11.0 7.6 – 9.7 15.7 – 18.1 Myrmotherula menetriesii 46.0 – 57.0 21.0 – 33.0 6.0 – 10.6 8.5 – 9.8 16.5 – 19.5 Myrmotherula guttata (no subspecies) – Rufous-bellied Antwren Band size: D-E

# Individuals Captured: 275 Similar Species: Plumage and extremely short tail distinctive, but beware of confusion with young ♂ antwrens in PF1 molt, especially ♂♂ M. menetriesii, as the combination of gray and brown can be similar. M. guttata, unlike the other antwrens, has boldly contrasting buffy- tipped wing covs forming bold wing bars.

Measurements: 50 Wing ♂ 46.0-54.0 (50.2 ± 1.6; n86) ♀ 46.0-54.0 (49.6 ± 1.5; n62) 40 Tail ♂ 21.0-29.0 (24.6 ± 1.6; n77) ♀ 19.0-30.0 (24.5 ± 1.9; n59) 30 Mass ♂ 8.5-12.0 (10.2 ± 0.8; n131) 20 ♀ 7.5-13.0 (10.4 ± 0.9; n84)

Bill ♂ 7.9-8.4 (8.2 ± 0.3; n3) 10 ♀ 8.5-8.8 (8.6 ± 0.2; n3) Tarsus ♂ 21.9-22.6 (22.2 ± 0.5; n2) line) bp (dotted or line) (solid molt with birds % 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 17.3-22.5 (20.8 ± 3.0; n3) Molt, n =272717522641783724352629 Skull: No information available, but Bp, n =001012700402 probably completes during F1 as in other Thamnophilids. Brood Patch: Observed in Jul and Oct, but there are few data available. Probably should be expected throughout the dry season. Molt-breeding overlap 33.3% (n3). Molt: Probably Complex Basic Strategy: no information on PF1; PBs complete, PA probably absent. Most frequent (>35%) from Jan to Mar and least frequent (<10%) in Sep. Age/Sex: BASIC I: ♀?♂ Unknown.

FORMATIVE I: ♀≠♂ (?) Unknown.

BASIC II: ♀≠♂ ♀ - Upperparts, head, and throat are olive- brown with a contrastingly ochraceous belly. Has bold tawny- orange med and gr covs forming two wing bars. Myrmotherula guttata (no subspecies) – Rufous-bellied Antwren

BASIC II: ♀≠♂ ♂ - Head, throat, and chest gray blending to tawny-brown in the belly and rump. Has bold tawny-orange med covs and gr covs forming two wing bars. Myrmotherula axillaris axillaris – White-flanked Antwren Band size: C

# Individuals Captured: 489 Similar Species: All ages and sexes easily separated from other small antwrens by contrasting white flanks, often concealed under folded wings. Measurements intermediate among antwrens (Table X), but plumage characteristics should be diagnostic.

Measurements: 50 Wing ♂ 47.5-56.0 (51.0 ± 1.7; n220) ♀ 46.0-56.0 (50.0 ± 1.5; n138) 40 Tail ♂ 31.0-44.0 (37.8 ± 2.2; n202) 30 ♀ 32.0-44.0 (37.4 ± 1.9; n133)

Mass ♂ 6.0-9.5 (7.6 ± 0.5; n257) 20 ♀ 6.0-9.0 (7.6 ± 0.7; n164) Bill ♂ 7.3-9.6 (8.6 ± 0.5; n14) 10 ♀ 7.9-9.4 (8.5 ± 0.4; n15) % birds with molt (solid line) or bp (dotted line) line) bp (dotted or (solid with molt % birds 0 Tarsus ♂ 16.4-18.0 (17.3 ± 0.6; n14) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 16.4-17.8 (17.0 ± 0.4; n15) Molt, n =302138373846906964746040 Skull: Completes, probably during F1. Bp, n =002261331201328199 Brood Patch: Present from Jul to Dec(-Feb?), but probably peaks from Sep to Nov. Molt- breeding overlap is 16.7% (n18). Molt: Complex Basic Strategy: PF1 partial, PBs complete. PF1 includes all body feathers, less and med covs, usually 4 (occasionally all) gr covs, and most or all rects. Peaks (>40%) in Nov and distinctly least (<5%) frequent in Jun, thus appears to peak before other antwrens. Age/Sex: BASIC I: ♀≠♂ ♀ - Generally brown with whitish flanks and similar to definitive plumage ♀♀, but with chestnut-toned upperparts. Rects distinctly pointed. ♂: Generally dusky brownish-gray with buffy spots on wing cov and tail. Rects distinctly pointed.

BASIC I: ♀≠♂ ♀ - Generally brown overall with white flanks and similar to definitive ♀♀, but note molt limits between the replaced med covs and retained pp covs and among the replaced inner gr covs and the more chestnut retained outer gr covs. This can be difficult to see, but often growth bars are distinctly aligned among the chestnut-edged remiges. Rects are rounded. Myrmotherula axillaris axillaris – White-flanked Antwren

FORMATIVE I: ♀≠♂ ♂ - Dark gray overall and similar to definitive ♂♂, but with molt limits between the replaced dark gray med covs and retained brownish-gray pp covs and among the replaced inner gr covs and retained outer gr covs. Often there is a brownish wash to the crown or back. There is considerable variation in the extent of black in the underparts, but there should always be at least a trace of black in the throat. Rects are rounded.

BASIC II: ♀≠♂ ♀ - The definitive plumage. Tawny-brown overall, slightly paler underneath, especially in belly, and has contrasting white flanks. Lacks molt limits among the wing covs and has rounded rects. Myrmotherula axillaris axillaris – White-flanked Antwren

BASIC II: ♀≠♂ ♂ - The definitive plumage. Dark grayish-black overall with distinctive white flanks, which are often concealed by the folded wing. Each wing cov and rect is boldly tipped white. Lacks molt limits and has rounded rectrices.

♂

♀ Myrmotherula longipennis longipennis – Long-winged Antwren Band size: D

# Individuals Captured: 688 Similar Species: Smaller than most other Thamnophilids, but both sexes are easily confused with other Myrmotherula antwrens. ♂ from M. menetriesii by black throat, but beware of young M. longipennis that lack or more often have just a trace of black in the throat. From M. axillaris by grayer overall plumage and lack of white flanks. ♀ from other Myrmotherula antwrens by white (not brownish) belly. The combination of wing and tail measurements have very little overlap with other Myrmotherula antwrens (Table X) and should help confirm plumage characteristics. 50 Measurements: Wing ♂ 52.0-63.0 (57.8 ± 1.8; n257) 40 ♀ 51.0-61.0 (56.1 ± 1.8; n252) Tail ♂ 29.0-41.0 (35.1 ± 2.1; n232) 30

♀ 29.0-39.0 (34.4 ± 2.0; n224) 20 Mass ♂ 7.0-11.0 (8.4 ± 0.7; n317)

♀ 6.5-11.0 (8.4 ± 0.8; n263) 10 Bill ♂ 8.1-9.6 (8.9 ± 0.4; n20) % birds% with molt (solid line) or bp (dotted line) 0 ♀ 7.6-9.7 (8.8 ± 0.5; n15) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Tarsus ♂ 16.0-18.0 (17.1 ± 0.5; n20) Molt, n =302138373846906964746040 ♀ 15.7-18.1 (17.0 ± 0.8; n13) Bp, n =002261331201328199 Skull: Completes (n5), probably during F1. Brood Patch: Mainly develops in ♀♀ and may also develop in ♂♂, but confirmation is needed. Molt-breeding overlap is 5.6% (n18). Molt: Complex Basic Strategy: PF1 partial, PBs complete. PF1 includes all body feathers, less and med covs, usually 3 (occasionally 1 or 2 more or less) gr covs, and most or all rects. Peaks (>40%) in Nov and is least frequent (<12%) from Apr to Jun. Age/Sex: BASIC I: ♀=♂ Similar to definitive ♀, but with less olive tones, more chestnut-brown overall including edging on remiges, with pale whitish throat, and buffy eye ring. Less covs often distinctly buffy-tipped, but beware of worn definitive feathers that appear similar (other characteristics of juvenal birds like gape, feather texture, aligned growth bars, and skin flaking should help confirm age). Also look for replaced body feathers and covs for sex determination at an early age.

Initial stages of PF1 which still mostly appears as B1, but note newly replaced (F1) less covs and back feathers; sex unknown Myrmotherula longipennis longipennis – Long-winged Antwren

FORMATIVE I: ♀=♂ Similar to the definitive ♀, but with molt limits among the gr covs with the replaced olive-brown washed inner gr covs and contrasting with the chestnut-brown washed outer covs.

BASIC II: ♀≠♂ ♀ - The definitive plumage. Unpatterned tawny-brown overall with white belly, tawny- brown throat, and all gr covs uniformly tawny-brown without chestnut washing.

♂ - The definitive plumage. Gray overall with black throat and bold white tips to wing covs. There is considerable variation in the amount of black in the throat with some birds approaching the gray throat of M. menetriesii, nearly lacking any black. This does not appear to be age related as at least one marked bird that aged 2 years did not acquire additional black in the throat with age. Myrmotherula menetriesii cinereiventris – Gray Antwren Band size: D

# Individuals Captured: 417 Similar Species: Plainest antwren at the BDFFP. Its short tail separates it from all other antwrens except M. guttata (Table X). ♂♂ in PB1 could resemble M. guttata, but note the lack of strong buffy-tipped wing bars. M. menetriesii lacks the black throat and white flanks or white belly of other small antwrens, but beware of potential confusion with some ♂M. longipennis that have little black in the throat. ♀♀ from other small antwrens by uniform tawny brown pattern with no white in flanks or belly. Measurements: 60 Wing ♂ 46.0-57.0 (52.2 ± 1.7; n162) 50 ♀ 48.0-55.0 (50.8 ± 1.6; n148) Tail ♂ 21.0-33.0 (27.2 ± 1.9; n155) 40

♀ 21.8-31.0 (27.0 ± 1.6; n137) 30 Mass ♂ 6.5-10.0 (8.2 ± 0.8; n190) 20 ♀ 6.0-10.6 (8.1 ± 0.8; n153)

Bill ♂ 8.8-9.8 (9.3 ± 0.4; n10) 10

♀ 8.5-9.8 (9.1 ± 0.5; n9) line) or bp (dotted line) (solid molt with birds % 0 Tarsus ♂ 17.0-19.5 (17.7 ± 0.7; n10) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 16.5-18.7 (17.3 ± 0.7; n9) Molt, n =271436343224686150635515 Bp, n = 0 0 2 1 0 3 22 12 9 3 10 0 Skull: Completes (n23), probably during F1. Brood Patch: Present Jul to Sep, but probably possible throughout the dry season. Has only been observed in ♀♀, but probably likely to develop in ♂♂. Molt-breeding overlap is 0.0% (n5), but may be higher as in other antwrens. Molt: Complex Basic Strategy: PF1 partial, PBs complete. PF1 includes all body feathers, less and med covs, usually 3 (occasionally 1 or 2 more or less) gr covs, and most or all rects. Molt peaks in Jan to Mar (>40%) with is least frequent (<25%) from Aug to Nov. Age/Sex:

BASIC I: ♀=♂(?) Like definitive ♀, but with less olive-tones and more chestnut-brown. ♂ may have grayer less covs and med covs than ♀, but this needs confirmation. Less covs often distinctly buffy- tipped, but beware of worn adults looking similar (other characteristics of juvenal birds like gape, feather texture, aligned growth bars, and skin flaking should help confirm age). Myrmotherula menetriesii cinereiventris – Gray Antwren

FORMATIVE I: ♀=♂ Similar to the definitive ♀, but with molt limits among the gr covs with the replaced bright olive-brown inner gr covs and contrasting with the dull brown washed outer covs.

BASIC II: ♀≠♂ ♀ - The definitive plumage. Unpatterned tawny brown. Med covs and gr covs unmarked (or slightly buffy-tipped due to wear) without molt limits.

♂ - The definitive plumage. Gray overall with distinct white tips to wing covs. Myrmotherula variants

M. longipennis This non-molting bird was observed with a few retained brown subadult (♀-like) feathers, which may suggest it was in B2 plumage resulting from an incomplete PB2 molt. In addition, the gr covs of this individual were unusually unmarked and pale. This plumage abnormality is unusual among antwrens and is not widespread in continuous forest or forest fragment populations; we have no clear explanation for this.

M. menetriesii This bird in PB2 molt (pp1-5 replaced, p6 in pin, ss8-9 replaced, s7 in pin) has retained (or perhaps replaced?) med covs that are especially pale and buffy-tipped, which is not typical of F1 or B2 med covs. cantator cantator – Warbling Band size: D

# Individuals Captured: 655 Similar Species: None. 50 Measurements: Wing ♂ 49.0-57.0 (52.6 ± 1.5; n239) 40 ♀ 47.0-56.5 (51.2 ± 1.4; n185) Tail ♂ 36.0-47.0 (41.3 ± 1.9; n218) 30 ♀ 33.0-47.0 (39.8 ± 2.2; n172) 20 Mass ♂ 10.0-14.0 (11.7 ± 0.8; n309)

♀ 9.0-14.5 (11.8 ± 1.0; n242) 10 Bill ♂ 8.2-9.9 (9.3 ± 0.4; n34) ♀ 8.1-9.8 (9.0 ± 0.5; n19) (solidline) with molt or bp (dotted% birds line) 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Tarsus ♂ 19.9-22.8 (21.4 ± 0.8; n34) Molt, n = 35 27 65 63 74 88 103 91 78 100 88 63 ♀ 19.5-22.7 (21.7 ± 0.7; n20) Bp, n =0 0 710139 32221237287 Skull: Completes (n) during F1. Brood Patch: Well developed in ♀♀ and also seen in ♂♂. Observed from Jun through Dec(- Feb?) and peaks (50%) in Sep. Molt-breeding overlap is 21.4% (n42). Molt: Complex Basic Strategy: PF1 partial, PBs complete. PF1 includes all body feathers, less and med covs, and inner 0-6 (or rarely more), but usually inner 2-4 gr covs. Peaks from Nov through Apr (>25%) and is least frequent (<15%) in Jul. Age/Sex:

BASIC I: ♀=♂(?) Reminiscent of definitive ♀, but without well-defined spots on wing covs, weak head streaking, and tawny underparts with a paler throat. It quickly begins to replace crown feathers, which are adult-like in color and useful for sex determination at an early age. Hypocnemis cantator cantator – Warbling Antbird

FORMATIVE I: ♀≠♂ ♀ - Like definitive ♀ with brown and head stripes, but note molt limits among gr covs or between the replaced med covs and retained gr covs (see F1 ♂ for an example); the replaced inner covs are bright brown with bold, well-defined buffy spots at the tips and contrast with the retained outer dull brown covs without well-defined buffy spots at the tips.

♂ - Like definitive ♂ with black and white head stripes, but note molt limits among gr covs (see F1 ♀ for an example) or between the replaced med covs and retained gr covs; the replaced inner covs are bright black with bold, well-defined white or buffy spots at the tips and contrast with the retained outer dull brown covs without well-defined buffy spots at the tips.

BASIC II: ♀≠♂ ♀ - The definitive plumage. The crown has brown and tan stripes. Spots on wing covs tend to be more buffy than ♂♂. All less, med, gr, and pp covs are evenly aged and have sharply defined white or buffy spots. Hypocnemis cantator cantator – Warbling Antbird

BASIC II: ♀≠♂ ♂ - The definitive plumage. The crown has bold black and white stripes. Spots on wing covs tend to be brighter white than in ♀, but this is variable with some ♂♂ having only 1 or 2 inner gr covs buffy- tipped and others with all gr covs being buffy-tipped. tyrannina saturatior – Band size: E

# Individuals Captured: 34 Similar Species: Twice as large as antwrens in mass. Note fairly distinct rictal bristles compared to other antbirds. It is almost identical to C. laeta waimiri and many birds may not be safely identified separable in the hand (song is most diagnostic), but C. laeta waimiri has not yet been captured at the PDBFF and has not been detected along ZF-3 despite the type specimen being collected 20 km S in the Ducke Reserve (Bierregaard et al. 1997). Tarsus length may be useful to separate the two species (see Table X). The belly feathers and tips of rects are pale-fringed in definitive ♂ C. t. saturatior, but not in C. l. waimiri; beware of young or worn C. t. saturatior that may lack this feature. Wing covs of definitive ♀ C. l. waimiri are bright rufous-orange and concolor with the underparts and auriculars, unlike C. t. saturatior which have dull brown wing covs and auriculars compared to bright rufous-orange underparts, but this distinction is subtle and may be subject to ware and age (Bierregaard et al. 1997).

Table X. Measurements of Cercomacra tyrannina saturatior and C. laeta waimiri reproduced from Bierregaard et al. (1997). Measurements were taken from specimens and should not be directly compared to live birds, especially tarsus and culmen, but are indicative of differences among sexes and species. Wing Tail Tarsus Culmen C. tyrannina saturatior ♂ 58.8-66.2 (62.5 ± 1.9, n28) 56.0-63.5 (59.7 ± 2.0, n29) 21.1-23.9 (22.8 ± 0.6, n28) 18.1-20.7 (19.3 ± 0.7, n29) ♀ 55.8-63.6 (59.1 ± 1.9, n23) 55.0-64.9 (58.6 ± 2.7, n22) 20.9-23.2 (22.2 ± 0.6, n21) 17.3-20.1 (18.8 ± 0.7, n23) C. laeta waimiri ♂ 60.0-63.4 (62.0 ± 1.4, n4) 58.3-61 (59.3 ± 1.3, n4) 23.6-24.2 (23.9 ± 0.3, n4) 19.0-19.3 (19.1 ± 0.2, n4) ♀ 59.2 (n1) 55.9 (n1) 23.2 (n1) 17.8 (n1) Measurements: 80 Wing ♂ 58.0-66.0 (61.7 ± 1.7; n19) ♀ 57.0-61.0 (58.1 ± 1.3; n12) 60 Tail ♂ 50.0-64.0 (58.9 ± 3.8; n16) ♀ 54.0-68.0 (58.0 ± 4.4; n13) Mass ♂ 15.0-19.0 (16.9 ± 1.0; n16) 40 ♀ 15.0-20.0 (16.4 ± 1.3; n13) 20 Skull: Completes, probably during F1. Brood Patch: Only seen once (Jul) on a ♂, 0 % birds with molt (solid circles) or bp (open circles) (open bp or circles) (solid molt with % birds but probably occurs regularly in both Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec sexes also from Aug to Nov (HBW). Molt, n = 400347721240 Molt-breeding overlap is 100% (n1). Bp, n =000032201100 Molt: Not well known. Probably Complex Basic Strategy. PF1 may include some or all body feathers and some less and med covs. Age/Sex:

BASIC I: ♀=♂(?) Unknown. Cercomacra tyrannina saturatior – Dusky Antbird

FORMATIVE I: ♀≠♂(?) ♀ - Unknown, but probably similar to the definitive ♀ with a combination of fresh and worn wing covs. ♂ - Unknown, but possibly with molt limits among covs with a mix of juvenile (unmarked brown) and buffy-tipped pale gray covs.

BASIC II: ♀≠♂ ♀ - The definitive plumage. Unmarked tawny-brown. Without molt limits. ♂ - The definitive plumage. All gray with white crescents to tips of wing covs. Without molt limits among med, gr, or pp covs; gr covs may typically be slightly paler gray than the med covs, producing a pseudo limit. Percnostola rufifrons subcristata – Black-headed Antbird Band size: D

# Individuals Captured: 796 Similar Species: ♂ from other antbirds with bold white wing markings by red eye and size. ♀ from other antbirds by red eye and uniformly orange throat, breast, and belly. Measurements: 50 Wing ♂ 63.0-78.0 (71.8 ± 2.3; n281) ♀ 63.4-78.0 (70.3 ± 2.3; n290) 40 Tail ♂ 50.0-71.0 (60.5 ± 3.0; n273) 30 ♀ 48.0-69.0 (59.6 ± 3.1; n279) Mass ♂ 20.0-36.0 (29.2 ± 2.0; n344) 20 ♀ 20.0-37.0 (28.7 ± 2.5; n339)

Bill ♂ 11.4-13.6 (12.6 ± 0.5; n46) 10 ♀ 11.0-13.7 (12.5 ± 0.6; n42)

Tarsus ♂ 30.9-34.8 (32.8 ± 0.9; n47) % birds with molt (solid line) or bp (dotted line) 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 29.7-35.2 (32.8 ± 0.7; n41) Molt, n = 54 61 77 80 120 124 156 152 100 100 121 73 Skull: Usually completes during PF1, but Bp, n =001412201859403440399 more study is needed. Brood Patch: Present between Jul and Dec(-Feb?) and develops in both ♂♂ and ♀♀. Molt- breeding overlap is 14.6% (n48). Molt: Complex Basic Strategy with supplemental plumage: PS1 partial, PF1 complete, PBs complete. PS1 includes most (or all?) body feathers, most or all less covs, most or rarely all med covs, and occasionally 1-3 gr covs, but no remiges. During PF1, S1 covs are replaced after the retained B1 covs, but before the pp complete. It is possible that the S1 body feathers are also replaced after the B1 feathers during PF1. The wing molt (either PF1 or PB) may occur at any time of year (>16%), peaking in Oct and Nov (> 40%) with a 2nd peak in Feb. These two peaks may represent the difference in timing between the PF1 (e.g. Oct to Feb) and definitive PB molts (Mar-Aug), but more study is needed. Wing molt is estimated to last about 220 days. This species regularly looses tail feathers when handled, thus care should be taken when assigning tail molt. Age/Sex:

BASIC I: ♀≠♂(always?) Generally ♀-like, but duller and lacking bold buffy orange tips to less, med, and gr covs; the tips of wing covs are dull orange. ♂♂ can (always?) have grayish-brown in the tail and back while ♀♀ are brown in the back and tail. Pp covs lack small pale- orange spots at tips. The iris is brown. Because it is not known if all ♂♂ are identifiable by plumage, ♀-like birds should be sexed as “unknown.” Percnostola rufifrons subcristata – Black-headed Antbird

SUPPLEMENTAL I: ♀≠♂(always?) Like B1, but with some to all less and med covs and occasionally some gr covs replaced and definitive ♀-like and contrasting with the retained dull med and gr covs. Rects retained from B1 are possible to use for sexing (see BASIC I). The tips to the replaced covs may be consistently narrower in ♂♂ than ♀♀, but more study is needed. The iris is brown.

This bird is in PS1, which may not complete before PF1 begins. Note the images under the 1st PREFORMATIVE MOLT show a more extensive PS1 replacement of wing covs than here. Based on the back and tail color, it is likely ♀ (see Basic I) 1ST PREFORMATIVE MOLT: ♀≠♂ ♀ - Some may not be distinguishable from birds in PS1 or S1 (thus should be sexed as unknown), but look for a combination of an extensive replacement of definitive ♀-like wing covs with an iris that has changed from brown to orange-red or red, which occurs when pp begin molting.

♂ - Look for replaced definitive ♂-like black and white wing covs constrasting with retained ♀-like S1 and B1 wing covs. The iris changes from brown to orange-red or red by the completion of PF1. Percnostola rufifrons subcristata – Black-headed Antbird

FORMATIVE I: ♀≠♂ ♀ - The definitive plumage. Bright tawny orange overall. Lacks molt limits among the gr and pp covs; gr and med covs have dark brownish-black bases and bold tawny orange tips. The crown is dusky orange (not black as in P. r. rufifrons) and the iris is dark orange to red.

♂ - The definitive plumage. Charcoal gray with black cap and throat. Wing covs lack molt limits and all are black with white fringe to tip. The iris is red.

Note: The covs in B1 and S1 plumages appear to be slightly different in P. r. rufifrons (based on LSU specimens). P. r. minor jansoni (probably a different species) may not have a supplemental plumage based on one immature bird in the LSU collection. Schistocichla leucostigma leucostigma – Spot-winged Antbird Band size: F

# Individuals Captured: 151 Similar Species: ♂confusing only because it superficially resembles several other all dark gray antbirds with white on the wing covs, but it lacks any pattern in the gray and has white spots (not crescents) on the wing covs. ♀ is most similar to Myrmeciza atrothorax, but larger with uniformly orange throat and chest (not paler whitish throat) and a gray (not dark brown) iris. Measurements: 60 Wing ♂ 62.0-70.0 (66.2 ± 1.8; n51) ♀ 61.0-70.0 (65.2 ± 2.1; n66) 50

Tail ♂ 53.0-64.0 (58.7 ± 2.7; n49) 40 ♀ 50.0-68.0 (58.9 ± 3.8; n62) Mass ♂ 21.0-29.0 (24.5 ± 1.6; n48) 30

♀ 21.0-30.0 (24.5 ± 1.8; n70) 20 Bill ♂ 12.1-13.0 (12.5 ± 0.7; n2) 10 ♀ 10.7-12.9 (11.9 ± 0.8; n7) Tarsus ♂ 30.3-31.4 (30.9 ± 0.8; n2) line) molt bp (dotted line) (solid % birds with or 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 29.1-30.5 (29.7 ± 0.5; n7) Molt, n =8 7 10212018172624243013 Skull: Probably completes during F1. Bp, n =000200253330 Brood Patch: Develops in both sexes. It has only been observed in Jul and Aug, but probably breeds throughout dry season. Molt-breeding overlap is 0.0% (n2). Molt: Complex Basic Strategy: PF1 partial, PBs complete. PF1 includes body feathers, less and med covs, and inner 3 to all gr covs, but not the alula. Age/Sex:

BASIC I: ♀=♂ All dark brown without any markings (at least in S. l. intensa), but less, med, and gr covs may have faint pale spots on the tips. The iris is dark brownish-black. Probably held very briefly.

FORMATIVE I: ♀=♂(?) ♀-like, but slightly paler underneath. This plumage is identified by molt limits among the gr covs with the replaced inner gr covs having distinct large spots (like the definitive ♀) contrasting with the retained weakly marked gr covs or occasionally molt limts are between the replaced gr covs and retained pp covs. The replaced covs in ♂♂ may have whiter spots than in ♀♀, but more study is needed. The retained alula is weakly marked with a pale tip. The iris is gray. Schistocichla leucostigma leucostigma – Spot-winged Antbird

FORMATIVE I: ♀≠♂ ♀ - The definitive plumage. Tawny orange underparts with a gray head and orange throat. Each less, med, and gr cov has a large round tawny-orange spot at the tip. Pp covs are brown, usually with a small tawny spot at each tip. The alula is boldly marked with a pale arrow-head. The iris is gray.

♂ - The definitive plumage. All gray with a distinct round white spot on the tip of each less, med, and gr cov and with or without a small white spot on the tip of each pp cov. Myrmeciza ferruginea ferruginea – Ferruginous-backed Antbird Band size: F

# Individuals Captured: 278 70 Similar Species: None. 60 Measurements: Wing ♂ 56.0-67.0 (63.0 ± 1.9; n103) 50 ♀ 57.0-66.0 (61.7 ± 1.9; n73) 40

Tail ♂ 45.0-63.0 (53.7 ± 3.1; n102) 30

♀ 48.0-60.0 (53.4 ± 2.7; n64) 20 Mass ♂ 18.5-31.0 (24.8 ± 1.8; n139) 10 ♀ 20.5-30.5 (24.6 ± 2.2; n94)

% birds with molt (solid line) and bp (dotted line) 0 Bill ♂ 11.1-12.4 (12.0 ± 0.6; n11) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 10.6-12.9 (11.7 ± 0.7; n9) Molt, n = 9 23 20 25 32 28 53 43 41 35 45 23 Tarsus ♂ 28.0-30.3 (29.1 ± 0.8; n10) Bp, n =00626171212890 ♀ 27.3-30.9 (29.3 ± 1.2; n9) Skull: Probably completes during F1. Brood Patch: Develops in both sexes. Breeding is most frequent from Jul to Nov, but may occur through Apr. Molt-breeding overlap is 30.0% (n20). Molt: Complex Basic Strategy: PF1 partial, PBs complete. PF1 includes all body feathers, rects, less and med covs and gr covs, but not pp covs and flight feathers. Molt is most frequent (>30%) from Apr to Jun with a 2nd peak in Dec to Jan and least frequent (<20%) from Feb to Mar. Age/Sex:

BASIC I: ♀=♂(?) Generally unmarked brown overall with a black throat and chest. Wing covs are unmarked and uniformly brown. Bare ocular patch is bluish-purple. Myrmeciza ferruginea ferruginea – Ferruginous-backed Antbird

FORMATIVE I: ♀≠♂ ♀ - Like definitive ♀ with a white throat, but note molt limits where the retained pp covs and alula are unmarked and brown and the replaced gr wing covs are black with bright buffy or white tips. Ocular patch is powder blue. The iris is dark brown.

♂ - As in Formative I ♀, but with black throat.

BASIC II: ♀≠♂ ♀ - The definitive plumage. Wing covs are without molt limits and are black with a white crescent at the tip. The ocular patch is powder blue. The iris is dark brown. The throat is white.

♂ - The definitive plumage. As in definitive ♀, but with a black throat. Myrmeciza atrothorax atrothorax – Black-throated Antbird Band size: E

# Individuals Captured: 14 Similar Species: Smaller than Schistocichla leucostigma. ♂ is uniquely-patterned with black cap and throat and white spots (not crescents) on wing covs. ♀ most like S. leucostigma, but with paler throat than chest (not nearly concolor) and brown tones in crown contrasting with grayish mask. Measurements: Wing 52.0-57.0 (54.6 ± 1.9; n12) Tail 50.0-56.5 (54.4 ± 2.1; n11) Mass 14.0-18.5 (15.7 ± 1.5; n13) Skull: Unknown, but probably completes during F1. Brood Patch: No information available. Molt: Unknown, but probably Complex Basic Strategy. It is possible that PF1 is partial as in Schistocichla. Age/Sex:

BASIC I: ♀=♂(?) Unknown, but without spots on wing covs.

FORMATIVE I: ♀=♂(?) Has molt limits either between the inner and outer gr covs, and/or between the gr and med covs, but more study is needed.

This bird is probably PB2 ♀ (pp1-2 replaced, p3 in molt, s9 in molt).

BASIC II: ♀≠♂ ♀ - Probably the definitive plumage. Without molt limits and with a buffy spot on the tip of each wing cov. Dull orange-brown on upperparts contrast with grayish mask, whitish throat and brighter orange underparts. ♂ - Probably the definitive plumage. Without molt limits and with a white spot on the tip of each wing cov. Gray overall with black crown and throat. Myrmornis torquata torquata – Wing- Band size: G

# Individuals Captured: 196 Similar Species: None. 100 Measurements: 80 Wing ♂ 88.0-98.0 (92.6 ± 2.7; n61)

♀ 84.0-99.0 (91.6 ± 2.6; n55) 60 Tail ♂ 34.0-45.0 (38.7 ± 2.4; n55) ♀ 33.0-43.0 (37.8 ± 2.4; n52) 40 Mass ♂ 38.0-51.0 (44.6 ± 2.8; n90) 20 ♀ 38.0-51.0 (43.9 ± 2.7; n77)

Bill ♂ 14.8-15.9 (15.3 ± 0.6; n3) line)andbp (dotted line) molt (solid % birds with 0 ♀ 13.5-15.6 (14.4 ± 1.1; n3) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Tarsus ♂ 29.1-30.6 (29.9 ± 0.8; n3) Molt, n =202328193623504525262716 Bp, n =000000403510 ♀ 28.2-28.5 (28.4 ± 0.2; n3) Skull: Completes (n9), but little other information available. Brood Patch: Little information available, but occurs in at least Oct and Nov. Based on these data and seasonal singing patterns, probably breeds during late dry season and early wet season (Sep to Mar?). Molt-breeding overlap is 14.3% (n7). Molt: Probably Complex Basic Strategy: PF1 complete (or partial?), PBs complete. PB1 may just include body feathers with less, med, and gr covs retained and ♀-like. Or more likely, the PB1 is complete, but the replaced covs in ♂ remain ♀-like (see Fig X). More study is needed. Molt is most frequent (>40%) between Mar and Jul and least frequent (<10%) in Sep. Age/Sex: BASIC I: ♀?♂ Unknown.

PREFORMATIVE I: ♀≠♂ Unknown.

Presumed PF1 ♂ (p1-3 new, p4 in pin, s2,5,6,8 new). Note replaced less and med covs are generally brown and tan (definitive ♀-like). Myrmornis torquata torquata – Wing-banded Antbird

FORMATIVE I: ♀≠♂ ♀: Not well understood, but with an orange chest like B2. It may not be possible to separate F1 ♀♀ from B2 ♀♀. The variation in black and white pattern around orange chest patch may be useful, but more study is needed. ♂: The throat is black as in the B2. In one case a bird was seen with the inner gr covs grayish-brown with a black-banded tip. The presumably replaced less covs were grayish- brown basally with bold chestnut edging (definitive ♀-like), and the terts were unmarked grayish-brown.

BASIC II: ♀≠♂ ♀ - The throat and chest is orange. The covs are brown and tan as in F1(?), but more study is needed. The black and white pattern bordering the orange chest is variable and may be more extensive than in F1, but more study is needed.

♂ - The throat and chest is black. The inner-most gr covs are gray with a black-banded tip. The less covs are gray basally and the terts are grayish- brown with a darker brown spot near the tip. Pithys albifrons albifrons – White-plumed Antbird Band size: F

# Individuals Captured: 2140 Similar Species: No other species has a distinctive white crest. The combination of rusty- orange belly and tail, gray back, and orange legs separates all ages from all other species. Measurements: 60 Wing 62.0-77.0 (69.6 ± 2.0; n1403) Tail 34.0-46.0 (39.9 ± 1.7; n1361) 50 Mass 16.0-24.5 (20.1 ± 1.3; n1863) 40 Bill 8.3-12.7 (11.0 ± 0.6; n142) Tarsus 18.9-27.4 (25.1 ± 1.1; n134) 30

Crest 22.02 ± 2.6; n26 20 Skull: Completes during PF1. Brood Patch: Never observed between 10

Mar and Jun, but present between Jul 0 % birds with molt (solid lines) or bp (dashed lines) and Dec(-Feb?). Both sexes may share Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec in incubation and develop BPs. Molt- Molt, n = 132 123 206 222 331 365 609 472 385 331 315 181 breeding overlap is 21.4% (n56). Bp, n = 0 0 19 11 13 77 200 96 130 111 87 34 Molt: Complex Basic Strategy: PF1 complete (or occasionally incomplete), PBs complete (or rarely incomplete). Molt is extremely prolonged; 45 birds in continuous forest (n18) and forest fragments (n27) were estimated to replace all 10 pp in 315 days. Wing molt completed 17 days faster in continuous forest than in fragments. Twice we have seen wing molt temporarily arrest during the molting process, which may be a strategy to deal with unpredictable breeding periods; five other times wing molt has arrested (appearing as molt limits among the pp), but these birds were never recaptured to see if molt resumed. Tail molt proceeds centripetally (begins with R6 and completes with R1). The adult supercilium and crest are evident and complete early in PF1, long before wing molt completes and often before p3 is replaced. Banders should examine retained wing and tail feathers for birds in molt to accurately determine age. Greater than 35% of birds captured at any time of year have wing molt, which is concordant with the long molt cycle, but molt appears to peak (>50% of birds captured) between Sep and Jan. Age/Sex:

BASIC I: ♀=♂ Lacks white crest and supercilium, has dull orange tarsi, and white gape. The bill is pale at the base. Gr and med covs are brownish-gray with chestnut edging. Pp covs are dull gray with a trace of brown. Pp and ss are brownish-gray and the terts often have chestnut tips. Inner covs and scapulars also often have chestnut tips. Rects are distinctly pointed. The iris is dark sooty brown. Pithys albifrons albifrons – White-plumed Antbird

PREFORMATIVE I: ♀=♂ The adult supercilium and crest are evident and complete early in PF1, long before wing molt completes and often before p3 is replaced. The bill and leg color also become definitive- like early in the PF1. Banders should examine contrast of replaced bright gray wing and tail feathers against retained brownish-gray feathers of molting birds to assess age, but beware of worn definitive feathers that appear similar to juvenal feathers.

FORMATIVE I: ♀=♂ The definitive plumage. The crest and supercilium are white, tarsi are bright orange, and bill is all black. Flight feathers are bright gray and fade to dull gray with wear. Some birds have small, but distinct, chestnut brown tips in terts, ss, and/or covs (is this age-related?). Rects are rounded. The iris is dark brown. Birds completing PF1 are nearly identical to birds in definitive PB and are not reliably aged because worn definitive outer pp are extremely similar to worn juvenal outer pp. Gymnopithys rufigula – Rufous-throated Antbird Band size: G

# Individuals Captured: 1097 Similar Species: Only Myrmciza ferruginea shares bluish bare skin around the eye, but the plumage is otherwise different, thus no species should be confused with Gymnopithys.

Measurements: 60 Wing ♂ 68.0-82.0 (75.3 ± 2.4; n313) ♀ 68.0-80.0 (73.8 ± 2.2; n261) 50

Tail ♂ 45.0-57.0 (50.8 ± 2.2; n296) 40 ♀ 43.0-57.0 (49.4 ± 2.2; n247) 30 Mass ♂ 23.0-35.0 (29.3 ± 1.9; n476) ♀ 22.5-35.0 (28.6 ± 2.2; n391) 20

Bill ♂ 10.3-13.6 (12.2 ± 0.7; n31) 10 ♀ 10.6-13.4 (11.8 ± 0.7; n32) % birds with molt (solid line) orbp (dotted line) 0 Tarsus ♂ 29.3-34.9 (32.0 ± 1.1; n29) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ♀ 27.9-32.8 (31.1 ± 1.0; n32) Molt, n = 96 64 102 120 154 196 278 245 188 157 201 105 Bp, n =0097722834652484015 Skull: Completes (n119) during PF1. Brood Patch: It well developed in ♀♀, but also develops in ♂♂. They are most frequent from Aug to Dec(-Jan?), with single observations in Apr, Jun, and Jul, thus may occur through the wet season occasionally. Molt-breeding overlap is 26.1% (n69). In 9 of 11 cases where BPs and degree of primary molt were recorded, wing molt was either nearly complete (≥ p8) or just initiating (p1). Molt: Complex Basic Strategy: PF1 complete, PBs complete. Molt occurs at any time of year, probably due to a slow feather replacement rates like Pithys; 30-50% of individuals are molting in any given month, peaking (>40%) during the wet season (Feb to Jun). Twelve birds in continuous forest (n4) and forest fragments (n8) were estimated to replace all 10 pp in 237 days. Age/Sex:

BASIC I: ♀=♂ The iris is dark brown. The bare ocular patch is dull powder blue. The chin is reddish- chestnut and the throat is brown. Wing covs are chestnut-brown and tips wear to a pale tawny-brown. Rects are relatively pointed. Gape is white. The concealed sexually dichromatic intrascapular patch is not present, but these are among the first feathers to grow during PF1 and can be used to determine the sex as in the definitive plumage when present. Gymnopithys rufigula – Rufous-throated Antbird

PREFORMATIVE I: ♀≠♂ ♀ - The definitive plumage. Has a tawny-orange concealed intrascapular patch. The iris is dark red, the bare ocular patch is bright powder blue, and the chin and throat are reddish- chestnut. Flight feathers and wing covs are brown with hint of olive and can appear similar to juvenile feathers when worn with pale tips, but with less chestnut color than juvenal feathers of the same wear. Rects are rounded. Birds completing PF1 are nearly identical to birds in definitive PB and are not reliably aged because worn definitive outer pp are extremely similar to worn juvenal outer pp. ♂ - The definitive plumage. As in F1 ♀ (see above), but with white intrascapular patch. poecilinotus – Scale-backed Antbird Band size: E

# Individuals Captured: 1569 Similar Species: No other antbird has extensive scaling on back and wing covs.

Measurements: 50 Wing ♂ 57.0-70.0 (64.1 ± 2.0; n431) ♀ 58.0-70.0 (62.7 ± 1.9; n541) 40 Tail ♂ 36.0-49.0 (42.4 ± 2.0; n415) ♀ 36.0-49.0 (42.0 ± 1.8; n511) 30 Mass ♂ 12.7-20.0 (16.8 ± 1.2; n599) 20 ♀ 13.0-20.5 (16.7 ± 1.3; n729)

Bill ♂ 6.4-11.8 (10.6 ± 1.0; n35) % birds withmolt orbp (lines) 10 ♀ 9.5-11.5 (10.5 ± 0.5; n45) 0 Tarsus ♂ 21.6-26.9 (25.4 ± 1.1; n36) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

♀ 22.9-27.5 (25.6 ± 0.9; n44) Molt, n = 158 137 241 222 291 306 402 319 241 302 330 156 Skull: Completes during F1. bp, n =0 0 1616192993563774589 Brood Patch: Both sexes develop BPs, which are present from Jul through Dec(-Feb?). Molt- breeding overlap is 16.7% (n40). Molt: Complex Basic Strategy: PF1 partial, PBs complete. PF1 includes all body feathers, less and med covs, and inner 0-3 gr covs. Molt most prevalent (>30%) from Dec to May and least prevalent (<20%) from Jul to Sep. Age/Sex:

BASIC I: ♀=♂ Like definitive ♀, but less, med, and gr covs dull gray, not glossy, with dull tawny-orange well-defined tips. Pp covs dull brown with dull tawny-orange well-defined tips.

FORMATIVE I: ♀=♂ Like definitive ♀, but with molt limits among gr covs or rarely between med and gr covs. Molt limits can be difficult to see as the retained B1 covs are very similar to definitive covs, but are dull brownish-black with weaker yellowish-orange tips contrasting with the replaced glossy dark black, bolder tawny-orange tipped covs. Pp covs are dull brown with poorly defined tawny-orange tips. Willisornis poecilinotus – Scale-backed Antbird

BASIC II: ♀≠♂ ♀ - The definitive plumage. Wing covs lack molt limits and are glossy dark black with bold tawny-orange tips. The head is orange and the throat and underparts are gray. Pp covs are dark brown with well-defined bright orange tips.

♂ - The definitive plumage. Generally all gray with lots of white scaling on the back and wing covs. Pp covs are black with small, but bold, white tips.

Note: In the BDFFP database, surely some F1 birds are misidentified as definitive ♀ because the molt sequence and delayed plumage maturation was previously unknown by banders. This probably explains why the sample sizes for measurements are about 20% higher in ♀♀. Some caution should be used when interpreting these ♀ measurements. naevia – Spot-backed Antbird Band size: unknown

# Individuals Captured: 179

Similar Species: None. 35

Measurements: 30 Wing ♂ 52.0-61.0 (57.2 ± 1.7; n68) 25 ♀ 53.0-60.0 (56.4 ± 1.8; n43) 20 Tail ♂ 31.0-43.0 (37.0 ± 2.2; n61) ♀ 33.0-40.0 (36.4 ± 1.8; n39) 15 Mass ♂ 10.0-15.0 (12.5 ± 1.0; n94) 10

♀ 10.0-15.0 (12.7 ± 1.0; n56) 5 Bill ♂ no data 0 % birds with molt (solid line) and bp circles) and bp (open line) molt (solid with birds % ♀ 8.6-9.4 (9.0 ± 0.6; n2) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Tarsus ♂ no data Molt, n =14131415151113231414118 Bp, n =000020000000 ♀ 22.7-23.5 (23.1 ± 0.6; n2) Skull: Probably completes (n2), but timing not known. Brood Patch: Both sexes develop BPs, which are present from Jul through Dec(-Feb?). Molt- breeding overlap is 16.7% (n40). Molt: No data available. Probably breeds during dry season when the frequency of molt is reduced. Age/Sex:

BASIC I: ♀?♂ Unknown.

FORMATIVE I: ♀?♂ Unknown

BASIC II: ♀?♂ ♀ - Probably the definitive plumage without molt limits. Throat is white and necklace against a buffy chest. ♂ - Probably the definitive plumage without molt limits. Throat is black and necklace on throat boldly black against a white chest.