Season relatively early, March-May (sometimes to June) in northeastern India and Myanmar, April in northwestern Thailand, and late February-May in China (15 Zhou, L., Q. Wang, and Y. Song (2003). [Breeding ecology of Aegithalos concinnus]. Chinese Journal of Ecology 22(2):24–27. (In Chinese with English summary.). Close , 16 Guo, G.-Y., Y.-B. Zhou, J. Zhang, K.-J. Tang, F. Zheng, and X.-J. Jing (2006). [Nest-site selection, breeding ecology and helper behavior of Aegithalos concinnus in northeastern Sichuan, China]. Chinese Journal of Zoology 41(6):29–35. (In Chinese with English summary.). Close , 13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ). In the western portion of its range, the breeding season of A. c. iredalei is similar, March-May/June. Breeding season of A. c. annamensis is similar, but extends from February-June. Black-throated Tits are single-brooded.

Nest usually sited up to 3 m above ground in fork or woven around several twigs in low tree or bush, occasionally to 12 m up on horizontal bough of deodar (Cedrus) or at tip of a pine branch, rarely in rough grass or other low, tangled vegetation (13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ).

Construction Process

Nest built by both sexes, female taking dominant role, with birds working over a protracted period, 10-11 days in central China (northeastern Sichuan; 16 Guo, G.-Y., Y.-B. Zhou, J. Zhang, K.-J. Tang, F. Zheng, and X.-J. Jing (2006). [Nest-site selection, breeding ecology and helper behavior of Aegithalos concinnus in northeastern Sichuan, China]. Chinese Journal of Zoology 41(6):29–35. (In Chinese with English summary.). Close ), and sometimes taking up to one month to finish nest construction in central China (southern Henan; 13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ).

Structure and Composition

Nests are made from green moss  , lichen, rootlets, bark scraps, hair, spider egg cases, and vegetable down, bound together with spider webs  , and densely lined with feathers and sometimes also wool, fur, or vegetable down. Black-throated tits also observed to steal nesting material from other species in central China (Henan; 13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ).

Dimensions

Nest is an oval ball 100-150 mm tall × 95-140 mm wide, with an entrance hole at side near top (13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ).

Size

Average size 13.09 × 10.14 mm (13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ).

Color and Surface Texture

Eggs described as white or pale pink, variably but usually finely spotted reddish, especially in a ring at larger end, occasionally unmarked (13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ).

Clutch Size

Clutch size three eggs in northeastern India and northern Myanmar, 3-5 in western Myanmar (Chin Hills), and 7 eggs in central China (southern Henan; 13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ). In the western portion of its range, clutch size 3-8 (but generally 3-6) for A. c. iredalei.

Egg Laying

Eggs are laid at 24-hour intervals.

Incubation by female or by both sexes (male roosts in nest), with the incubation period ca. 14-16 days (13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ).

Duration of nestling period in central China (southern Henan) on average 15 days (13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ).

Chicks are fed by both parents (13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ), and sometimes helpers (see Cooperative Breeding).

Black-throated Tits are sometimes cooperative breeders, with 1-2 helpers (usually males who are failed breeder and redirect help to close kin), especially during provisioning stage; in a study in central China (southern Henan), ca. 20% of nests tended by helpers, which commonly assisted in provisioning offspring (13 Li, J., L. Lv, Y. Wang, B. Xi, and Z. Zhang (2012). Breeding biology of two sympatric Aegithalos tits with helpers at the nest. Journal of Ornithology 153(2):273–283. Close ); helpers also occasionally observed incubating as per another study in central China (northeastern Sichuan; 16 Guo, G.-Y., Y.-B. Zhou, J. Zhang, K.-J. Tang, F. Zheng, and X.-J. Jing (2006). [Nest-site selection, breeding ecology and helper behavior of Aegithalos concinnus in northeastern Sichuan, China]. Chinese Journal of Zoology 41(6):29–35. (In Chinese with English summary.). Close ).

After fledging, young are dependent on parents for at least ten days.