Breeding

Nesting of Cuban Bullfinch on Cuba occurs from March to August (Gundlach 1876, Valdés 1984, García 1992, Raffaele et al. 2003, Garrido and Kirkconnell 2011) but pairs may be found as early as January (Ayón personal observations). The nest is large and globular, with a side entrance. The nest is made of dry grasses, leaves, tree bark, rootlets, horse and goat hair, and feathers, and is located in a bush or low part of a tree no more than 2 m above the ground (Bursera sp. see images) (Gundlach 1876, Bond 1960, García 1992, Ruiz et al. 2006, Segovia 2007, Garrido and Kirkconnell 2011, Ayon, Ruiz and Iñigo-Elias obs. pers.). Other nest materials identified are fiber of Coccotrhinax litoralis and Tillandsia usneoides, Tillandsia fasciculata, Tillandsia recurvata, Belairia spinosa, Smilax havanensis, and Tollumnia sp. (Ruiz et al. 2006).

The nest is constructed by both sexes. Nest dimensions are: outside diameter 10.3 cm, inside diameter 4.2 cm, height 16.3 cm, depth 10.4 cm, mean height above the ground 1.80 m, and weight 34 g (García (1992). In Cayo las Brujas, in northern Villa Clara Province, nest measurements are: 13 cm high; 11.5 cm diameter, with a side entrance of 4.5 cm diameter. The nest is placed over thorny or creeper plants, at a height from 1-6 m. (Ruiz et al. 2006). Plants that form the substrate for nests of Cuban Bullfinch in Cayo Las Brujas, Cuba include Pilosocereus brooksianus (known locally as jitira), Smilax sp., Malpighia suberosa (palo bronco), Pictetia sp. (yamaquey), Consolea macracantha (tuna de cruz), Acacia macracantha (guatapaná), Harrisia eriophora (jijira), Ritterocereus hystrix (cardón), and Tabebuia sp. (roble blanco) (Ruiz et al. 2006).

Cuban Bullfinch lays three to five eggs that are whitish with a greenish cast, spotted with reddish brown and lilac, the spots concentrated at the larger end (Gundlach 1876, Bond 1960, Raffaele et al., 2003, Garrido and Kirkconnell 2011). The incubation period begins on the third or fourth day after the first egg is laid and only the female incubates (at least in captivity) in the 13 to 14 days length process; fledging occur at 14-17 days (Ayón personal observations). Gundlach (1876) mentions the measurements of an egg as 21 x 15 mm. From eight captive breeding pairs (Ayón unpublished data) the average clutch size was 2.4 eggs/clutch, with a range from 1 to 4 eggs.

Nestlings are completely naked when hatched, with a lilaceous skin, and only two or three hairy feathers in the head. The beak is black, wide and slightly down curved. The mouth lining is red and the commissure is white. The average weight at the third day is 2 g. The first pin feathers (wings and spinal line) emerge through the skin at the fourth or fifth day; also, the eyes start opening by this time. By day 12, the head is almost completely covered with sheathed feathers, wing sheaths are more developed and the tail is observed; the ears are more developed and the eyes totally opened; also, they are able to stand on their legs. The nest is abandoned by day 16-17 (Ayón personal observations).