Breeding behaviour of Purple Sunbird, Cinnyris asiaticus (Latham, 1790) in semiurban area of Punjab

Abstract

During the breeding seasons 2017-2020, breeding activities of the Purple Sun-Bird (PSB), Cinnyris asiaticus were studied in 16 nesting sites located in the northern rural and semi-urban outskirts of the Khanna city in Punjab. Observations on nest building, incubation, hatching, feeding, growth, fledging and other behavioural aspects of the parents/chicks were inferred from video-records, photographs and direct observations made on 11 clutches laid in 07 nests. In the study area the breeding season extended from March to July and the mean value of the nest structure parameters, namely, nest length, nest width and entrance diameter were 15.2 ± 0.63 cm (range: 14-16 cm), 6.61 ± 0.36 cm (range: 6.0-8.0 cm) and 3.67 ± 0.34 cm (range: 3.0-4.0 cm) respectively. The clutch size was 2 eggs (n=6) or 3 eggs (n=4) and the egg (n=17) weight, length and breadth measured 1.13 ± 0.06 gm, 16.61 ± 0.43 mm and 11.49 ± 0.28 mm, respectively. Most of the eggs were laid in morning hours between 6:30 am to 7:30 am (n=25) and the incubation period was recorded 12 days (n=3), 13 days (n=6) and 16 days (n=1). Video records of 80.62 hours diurnal observation time (OT) recorded over 07 consecutive days (between 6:30am – 6:30pm each day) of full incubation revealed that the PSB female spent 51.59 hours (64% OT) and 29.03 hours (36% OT) as attentive periods and un-attentive Periods respectively. Synchronous hatching was completed in one or two successive days (within 24 hours) except for a single three-egged clutch with its youngest chick hatching asynchronously on third successive day. During nestling phase of 13 – 16 days, eyes of the altricial chicks opened on 5th day after hatching and approaching the day-10, the chick appeared fully feathered. During the biparental food provisioning OT of 54 hours referable to 05 days of the second half on nestling life, male and female PSB contributed 173 (33.20%) and 348 (66.80%) feeding visits respectively at a rate of 9.44 visits per hour. During this OT, the male and female PSB were seen carrying faecal sacs of chicks away from nest on 03 and 79 occasions respectively. The review of video-records showed that the female Purple Sunbird made use of nest fibers from the inner lining of the nest, as a tool for removing the defective egg from the nest. One of the nests was used in two consecutive breeding seasons and 04 broods were successfully raised in the same nest. The Oriental Garden Lizard, Calotes versicolor was noticed as a nest predator.