Breeding

The Scaly Weaver breeds at any time of year when conditions are favorable; peak months are February–March in Zambia, March–April in Namibia, December–April in Botswana, January–March in Zimbabwe, and January–June in South Africa (1 Craig, A. J. F. K. (2004). Ploceus olivaceiceps (Reichenow). Olive-headed Weaver. In The Birds of Africa. Vol. VII. (C. F. Fry and S. Keith, Editors), Christopher Helm, London, United Kingdom. pp. 189–191. Close ).

Monthly egg-laying records are available for many regions (Table 1).

Site Characteristics

The Scaly Weaver is not a colonial nester, but nests are sometimes clustered in a relatively small area (64 Skead, C. J. (1995). Life-history notes on East Cape bird species (1940-1990). Volume 1. Algoa Regional Services Council, Port Elizabeth, South Africa. Close ). Nests are occasionally found almost side-by-side in a single tree (64 Skead, C. J. (1995). Life-history notes on East Cape bird species (1940-1990). Volume 1. Algoa Regional Services Council, Port Elizabeth, South Africa. Close ).

The nest is wedged among thin branches of small or large (up to 6 m) thorn bushes or trees, usually close to the center and near the canopy of the tree (2 Dean, W. R. J. (2005). Scaly-feathered Finch Sporopipes squamifrons. In Roberts Birds of Southern Africa. 7th edition (P. A. R. Hockey, W. R. J. Dean and P. G. Ryan, Editors), Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa. pp. 1005–1006. Close , 91 Engelbrecht, D. (2023). Nests and nest sites of the Scaly-feathered Weaver. The Lark 46:65–71. Close ). Specific trees that have been recorded are sweet thorn (Vachellia karroo) (64 Skead, C. J. (1995). Life-history notes on East Cape bird species (1940-1990). Volume 1. Algoa Regional Services Council, Port Elizabeth, South Africa. Close ), camelthorn (Vachellia erioloba) (92 Milton, S., and R. Dean. (1999). Big old camelthorn trees. Key resource for Kalahari wildlife. African Wildlife 53(5):10-12. Close ), umbrella thorn (Vachellia tortilis), and buffalo thorn (Ziziphus mucronata)( (50 Jubber, W. (2011). Establishment of a resident pair of Scaly-feathered Finch in the Makuleke Contract Park, northern Kruger National Park. Ornithological Observations 2:54-57. Close ). In Botswana, it prefers Vachellia mellifera (93 Penry, H. (1994). Bird Atlas of Botswana. University of Natal Press, Pietermaritzburg, South Africa. Close ). In Limpopo Province, South Africa, three nests were in umbrella thorn trees, one in a common spike-thorn (Gymnosporia buxifolia), and one in a hairy caterpillar pod (Ormocarpum trichocarpum) tree (74 Engelbrecht, D. (2023). Field notes: Scaly-feathered Weaver. Lark 45:95–99. Close ).

The nest height is usually 0.9–4.2 m (1.7 m, n = 50) above ground (2 Dean, W. R. J. (2005). Scaly-feathered Finch Sporopipes squamifrons. In Roberts Birds of Southern Africa. 7th edition (P. A. R. Hockey, W. R. J. Dean and P. G. Ryan, Editors), Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa. pp. 1005–1006. Close ). In the Eastern Cape Province, the nest height ranged from about 1.8 to 3.6 m above ground (64 Skead, C. J. (1995). Life-history notes on East Cape bird species (1940-1990). Volume 1. Algoa Regional Services Council, Port Elizabeth, South Africa. Close ). In northern Namibia, nests are usually lower at 1–2m (77 Hoesch, W., and G. Niethammer (1940). Die Vögelwelt Deutsch-Sudwestafrikas namentlich des Damara- und Namalandes. Journal für Ornithologie 88(Supplement). 404 pp. Close ), presumably, because the vegetation in that region is generally shorter. In Zimbabwe, the nest height is normally 1.2–2.1 m above ground, but nests were found as low as ~80 cm and as high as 6 m in some of the larger thorn trees (94 Vincent, A. W. (1949). On the breeding habits of some African birds. Ibis 91:483-507. Close ). In the Limpopo Province, most nests are in trees <2.2 m tall but can be as high as 4 m, and the nest height ranged from 1.5–3.5 m above ground (74 Engelbrecht, D. (2023). Field notes: Scaly-feathered Weaver. Lark 45:95–99. Close ).

Nests are often placed in close proximity to previously used nests, and new nests are occasionally built on top of obviously old ones which had shrunk by weathering (64 Skead, C. J. (1995). Life-history notes on East Cape bird species (1940-1990). Volume 1. Algoa Regional Services Council, Port Elizabeth, South Africa. Close ). It has been recorded to roof over disused cup-shaped nests of shrikes (Laniidae) and flycatchers (Muscicapidae) (2 Dean, W. R. J. (2005). Scaly-feathered Finch Sporopipes squamifrons. In Roberts Birds of Southern Africa. 7th edition (P. A. R. Hockey, W. R. J. Dean and P. G. Ryan, Editors), Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa. pp. 1005–1006. Close ).

Construction Process

The stages of nest construction are as follows: the pair places a few loose blades and stems of grass among twigs, thorns, and leaves. This is built up to form a shallow cup or platform, with the sides projecting up somewhat more than the rear and the front not projecting up at all. The nest is then extended to form a thin-walled, semi-domed cup. Finally, the walls are thickened, and the lateral entrance is made smaller, but the roof remains thin and transparent, at least in roosting nests (78 Collias, N. E., and E. C. Collias (1964). Evolution of nest building in the weaver birds (Ploceidae). University of California Publications in Zoology 73:1–239. Close ).

In captivity, a female built the nest while the male brought material (3 Craig, A. J. F. K. (2010). Family Ploceidae (weavers). In Handbook of the Birds of the World, Volume 15: Weavers to New World Warblers (J. del Hoyo, A. Elliott, and D. A. Christie, Editors), Lynx Edicions, Barcelona, Spain. pp. 74–197. Close ). The role of individuals during the construction of roosting nests in the wild is not known.

Structure and Composition

The Scaly Weaver nest is an untidy mass of pale, dry grass stems and inflorescenses (91 Engelbrecht, D. (2023). Nests and nest sites of the Scaly-feathered Weaver. The Lark 46:65–71. Close ). Grass species typically used include the stiff grass stems and flowering heads of Androgopon, Aristida, Digitaria, Eragrostis, Sporobolus, and Urochloa spp. (3 Craig, A. J. F. K. (2010). Family Ploceidae (weavers). In Handbook of the Birds of the World, Volume 15: Weavers to New World Warblers (J. del Hoyo, A. Elliott, and D. A. Christie, Editors), Lynx Edicions, Barcelona, Spain. pp. 74–197. Close ). Two nest types can be distinguished, namely roosting nests and breeding nests (91 Engelbrecht, D. (2023). Nests and nest sites of the Scaly-feathered Weaver. The Lark 46:65–71. Close ). It is not known if breeding nests are simply roosting nests adapted for breeding purposes or if a new nest is constructed specifically for breeding (91 Engelbrecht, D. (2023). Nests and nest sites of the Scaly-feathered Weaver. The Lark 46:65–71. Close ). Roosting nests range from small, flimsy, and see-through structures to fairly large thatch platforms with or without a roof, or sometimes with a raised wall on one side, and are not lined (94 Vincent, A. W. (1949). On the breeding habits of some African birds. Ibis 91:483-507. Close , 91 Engelbrecht, D. (2023). Nests and nest sites of the Scaly-feathered Weaver. The Lark 46:65–71. Close ) (see ). Several roosting nests may be constructed in a small area, e.g., 7 nests in 250 m² in the Limpopo Province, South Africa, but usually, there is only one roosting nest per tree (91 Engelbrecht, D. (2023). Nests and nest sites of the Scaly-feathered Weaver. The Lark 46:65–71. Close ). Breeding nests look similar in appearance, but the walls and roof of such nests are thick and lined with finer plant down, grass inflorescences, panicles of Natal red top Melinis repens, feathers (especially Helmeted Guineafowl (Numida meleagris) feathers), and even animal hair (see ). Sometimes the green stems and flowers of aromatic Pentzia spp. are included in the nest structure (2 Dean, W. R. J. (2005). Scaly-feathered Finch Sporopipes squamifrons. In Roberts Birds of Southern Africa. 7th edition (P. A. R. Hockey, W. R. J. Dean and P. G. Ryan, Editors), Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa. pp. 1005–1006. Close ), possibly as a fumigant to repel ectoparasites (95 Milton, S. J., and W. R. J. Dean (1999). The selective use of green aromatic plants in Karoo bird nests. Ostrich 70(3/4):243-245. Close ). The lining of a breeding nest forms a tight "seal" around the breeding chamber and will, in all likelihood, prevent rainwater from seeping into the nest chamber (91 Engelbrecht, D. (2023). Nests and nest sites of the Scaly-feathered Weaver. The Lark 46:65–71. Close ).

All breeding nests and most roosting nests have a spout-like side entrance tunnel, usually pointing slightly downwards, but the entrance itself can be difficult to see as it often appears collapsed due to the untidy arrangement of the grass stems used to create the spout.

Dimensions

The nest is about 200 mm long (spout to the back wall, of which the spout is about 80 mm), 110 mm high, and 80–100 mm wide. The entrance, which is partly obscured by the fine grass ends, is about 35 mm in diameter (96 Tarboton, W. (2001). A Guide to the Nests and Eggs of Southern African Birds. Struik Publishers, Cape Town, South Africa. Close , 91 Engelbrecht, D. (2023). Nests and nest sites of the Scaly-feathered Weaver. The Lark 46:65–71. Close ). Two roosting nests collected on the Polokwane Plateau weighed 6.1 g (dimensions: nest length, i.e., from the entrance of the spout to the back of the nest, including a 60 mm spout = 160 mm, nest width = 85 mm, and nest height = 90 mm) and 23.6 g (nest length = 225 mm, nest width = 134 mm, no roof or spout, only a raised wall on one side), demonstrating the substantial size variation of roosting nests. One breeding nest weighed 11.9 g and had the following dimensions: nest length, including a 50 mm spout) = 170 mm, nest height = 84 mm, and nest width = 80 mm (91 Engelbrecht, D. (2023). Nests and nest sites of the Scaly-feathered Weaver. The Lark 46:65–71. Close ). There is no preferred entrance direction for nest spouts (91 Engelbrecht, D. (2023). Nests and nest sites of the Scaly-feathered Weaver. The Lark 46:65–71. Close ).

Shape

The eggs are sub-elliptical.

Size

For egg sizes from across its range, the dimensions are given as 15.8 mm (range 14.8–17.8) x 11.4 mm (range 10.2–12.2), n = 171 (97 Schönwetter, M., and W. Meise, Editors (1983). Handbuch der Oölogie. Familie Ploceidae. Academie-Verlag, Berlin, Germany. Close ).

In Namibia, the egg size is 15.5 mm (range 14.5–16.9) x 11.2 (range 10.8–11.9), n = 37 (98 Brown, C. J., P. A. Bridgeford, S. G. Braine, M. Paxton, and W. Versfeld (2015). Breeding data on the birds of Namibia: laying months, colony and clutch sizes and egg measurements. Ornithological Observations 6:92–196. Close ).

In Zimbabwe, it is 15.9 mm (range 14.6–18.0) x 11.6 mm (range 10.8–12.5), n = 22 (94 Vincent, A. W. (1949). On the breeding habits of some African birds. Ibis 91:483-507. Close ).

In Limpopo Province, South Africa, it is 15.6 mm ± 0.67 SD (range 14.4–16,5) x 11.1 mm ± 0.2 SD (range 10.7–11.5), n = 14 (74 Engelbrecht, D. (2023). Field notes: Scaly-feathered Weaver. Lark 45:95–99. Close ).

Mass

Of 14 eggs measured in 5 nests, the mean mass of fresh eggs was 1.05 g (n = 4) (74 Engelbrecht, D. (2023). Field notes: Scaly-feathered Weaver. Lark 45:95–99. Close ), comparing well with the egg mass of 1.07 g reported by (97 Schönwetter, M., and W. Meise, Editors (1983). Handbuch der Oölogie. Familie Ploceidae. Academie-Verlag, Berlin, Germany. Close ). The estimated egg mass of 10 eggs that were four days or older when data were collected was 1.17 g (74 Engelbrecht, D. (2023). Field notes: Scaly-feathered Weaver. Lark 45:95–99. Close ).

Eggshell Thickness

Information needed.

Color and Surface Texture

Eggs are glossy and pale greenish or bluish, heavily clouded, blotched, and spotted with grayish brown (2 Dean, W. R. J. (2005). Scaly-feathered Finch Sporopipes squamifrons. In Roberts Birds of Southern Africa. 7th edition (P. A. R. Hockey, W. R. J. Dean and P. G. Ryan, Editors), Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa. pp. 1005–1006. Close ).

Clutch Size

The clutch size ranges from 3–5 eggs (3 Craig, A. J. F. K. (2010). Family Ploceidae (weavers). In Handbook of the Birds of the World, Volume 15: Weavers to New World Warblers (J. del Hoyo, A. Elliott, and D. A. Christie, Editors), Lynx Edicions, Barcelona, Spain. pp. 74–197. Close ). There are slight regional differences in mean clutch sizes. In Namibia, the mean clutch size is 3.7 eggs, range 2–6, n = 63 (98 Brown, C. J., P. A. Bridgeford, S. G. Braine, M. Paxton, and W. Versfeld (2015). Breeding data on the birds of Namibia: laying months, colony and clutch sizes and egg measurements. Ornithological Observations 6:92–196. Close ), in Zimbabwe it is 3.8 eggs, range 1–7, n = 138 (99 Benson, C. W., R. K. Brooke, and C. J. Vernon (1964). Bird breeding data for the Rhodesias and Nyasland. Occasional Papers of the National Museums of Southern Rhodesia 27:30-105. Close ), in Zambia it is 4.5 eggs, range 2–6, n = 8 (45 Dowsett, R. J., D. R. Aspinwall, and F. Dowsett-Lemaire (2008). The Birds of Zambia. Tauraco Press & Aves, Liège, Belgium. Close ), and in South Africa (Limpopo Province) it is 4.2 eggs, range 3–5, n = 6 in nests where laying was completed (74 Engelbrecht, D. (2023). Field notes: Scaly-feathered Weaver. Lark 45:95–99. Close ).

Egg Laying

No information, but presumably at daily intervals.

Onset of Broodiness and Incubation in Relation to Laying

At two nests in Limpopo Province where four nestlings hatched, three hatched on the same day and the fourth on the following day. This suggests that incubation started after the third egg was laid, or when the penultimate egg was laid (74 Engelbrecht, D. (2023). Field notes: Scaly-feathered Weaver. Lark 45:95–99. Close ).

Incubation Period

Incubation period is 10–12 days (96 Tarboton, W. (2001). A Guide to the Nests and Eggs of Southern African Birds. Struik Publishers, Cape Town, South Africa. Close , 3 Craig, A. J. F. K. (2010). Family Ploceidae (weavers). In Handbook of the Birds of the World, Volume 15: Weavers to New World Warblers (J. del Hoyo, A. Elliott, and D. A. Christie, Editors), Lynx Edicions, Barcelona, Spain. pp. 74–197. Close ). The incubation period in captivity was 11 days (100 Ziswiler, V. (1968). Die taxonomische Stellung der Gattung Sporopipes Cabanis. Bonner zoologische Beiträge 19: 269-279. Close ).

Parental Behavior

Incubation is by the female only (96 Tarboton, W. (2001). A Guide to the Nests and Eggs of Southern African Birds. Struik Publishers, Cape Town, South Africa. Close , 3 Craig, A. J. F. K. (2010). Family Ploceidae (weavers). In Handbook of the Birds of the World, Volume 15: Weavers to New World Warblers (J. del Hoyo, A. Elliott, and D. A. Christie, Editors), Lynx Edicions, Barcelona, Spain. pp. 74–197. Close ). In captivity, birds incubate in bouts of 2–41 min (mean = 19 min), and leave the nest for bouts of 2–12 min (mean = 5 min), giving a calculated attentive period of 79.2% (100 Ziswiler, V. (1968). Die taxonomische Stellung der Gattung Sporopipes Cabanis. Bonner zoologische Beiträge 19: 269-279. Close ).

At two nests in Limpopo Province, four nestlings hatched; three hatched on the same day and the fourth on the following day (74 Engelbrecht, D. (2023). Field notes: Scaly-feathered Weaver. Lark 45:95–99. Close ).

Growth and Development

The growth and development of Scaly Weaver nestlings were described from one nest in Limpopo Province (74 Engelbrecht, D. (2023). Field notes: Scaly-feathered Weaver. Lark 45:95–99. Close ):

Newly hatched chick (Day 0) is naked, skin pale-pinkish with sparsely distributed, wispy, pale buff tufts of down on the dorsal, humeral, alar, and capital pterylae. No feather tracts are visible below the skin. The eyes are closed. The gape is thick and white to pale-yellow. The bill is yellow with a horn-colored tip. The neosoptiles of the primaries, secondaries, and rectrices are visible. On the following day (Day 1), the chick appears the same as on Day 0. On Day 2, subcutaneous pins are visible below the skin, and the eyes are still closed. On Day 3, the first primaries may emerge in pin. On Day 4, all primary and some secondary remiges are in pin. The eyes begin to open, but only as slits. On Day 5, all the primaries and secondaries are in pin, but no other tracts are visible yet. The eyes are still open as slits. On Day 6, all the feather tracts are in pin, but no feathers are in brush yet. The eyes are now fully open. On Day 7, the pin feathers continue growing, and some feathers are in brush. On Day 8, all feather tracts have at least some feathers in brush, and most of the primaries and secondaries are in brush. On Day 9, all the feathers are about 20% in brush. On Day 10, all the primaries are about 33% in brush. On Day 11, all the primaries are about 50% in brush.

Feeding

Nestlings are fed seeds and invertebrates by both sexes (3 Craig, A. J. F. K. (2010). Family Ploceidae (weavers). In Handbook of the Birds of the World, Volume 15: Weavers to New World Warblers (J. del Hoyo, A. Elliott, and D. A. Christie, Editors), Lynx Edicions, Barcelona, Spain. pp. 74–197. Close ).

Cooperative breeding has not been demonstrated in this species, but in a global review of parental care, it has been inferred to occur (101 Cockburn, A. (2006). Prevalence of different modes of parental care in birds. Proceedings of the Royal Society of London (Series B Biological Sciences) 273:1375-1383. Close ). At one nest under observation, the author suspected cooperative breeding but was unable to confirm it (102 Steyn, P. (1996). Nesting Birds: the Breeding Habits of Southern African Birds. Fernwood Press, Vlaeberg, South Africa. Close ).

Not recorded.

Departure from Nest

The mean nestling period is 16 days (range 14–18 d, n = 8) (2 Dean, W. R. J. (2005). Scaly-feathered Finch Sporopipes squamifrons. In Roberts Birds of Southern Africa. 7th edition (P. A. R. Hockey, W. R. J. Dean and P. G. Ryan, Editors), Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa. pp. 1005–1006. Close ). At one nest in the Limpopo Province, the nestlings fledged on day 15 (day 14 for the youngest) (74 Engelbrecht, D. (2023). Field notes: Scaly-feathered Weaver. Lark 45:95–99. Close ).

Information needed.