SOME NOTES ON BREEDING BEHAVIOUR OF BROWN-BACKED INDIAN ROBIN COPSYCHUS FULICATUS CAMBAIENSIS (LATHAM, 1790) IN AGRICULTURAL LANDSCAPE OF PUNJABCharn Kumar, Sandeep Kaur Thind and Amritpal Singh Kaleka
During the breeding seasons 2017-2020, breeding activities of the Brown-backed Indian Robin, Copsychus fulcatus cambaiensis were studied for eight clutches laid in three nests built in the northern semi-urban outskirts of Khanna city in Punjab. Observations on nest building, incubation time-budgeting, hatching, growth, parental provisioning frequency, removal of fecal sacs, and fledging of young ones were inferred from video-records totaling 316.47 hours, direct field observations, photographs and nest visits. These nesting cycles extended from March to July. The breeding pairs built oval cup shaped nests and the shortest diameter, longest diameter and depth measured on average 5 cm, 6 cm and 4.5 cm respectively. The clutch size was 2 eggs (n=3), 3 eggs (n=3) and 4 eggs (n=2) and the mean egg length, breadth and weight measured 19.77Â±0.86 mm, 14.57Â±0.30 mm and 2.23Â±0.16 g respectively (n=16). The eggs were laid in morning hours before 8:00 am and the incubation period was recorded 11 or 12 days (mean: 11.5 days, n=6). Review of the video records of 127.83 hours diurnal total observation time (TOT) recorded over 10 consecutive days (between 5:00 am - 8:00 pm each day) of full incubation at the focal nest revealed that the female invested 55.47 hours (43.39% TOT) and 72.36 hours (56.61% TOT) as attentive periods and inattentive periods respectively. Hatching was completed synchronously in one or two successive days except for a single three-egged clutch with its youngest chick hatching asynchronously on the third successive day. During the nestling phase of 12 - 15 days, eyes of the altricial chicks opened on 8th day after hatching and approaching the day- 12, the chick appeared fully feathered. Food provisioning was biparental and in TOT of 184.14 hours referable to 14 days of nestling life, male and female IR contributed a total of 1652 feeding visits at the nest, 878 (53.15%) and 774 (46.85%) feeding visits respectively at a rate of 8.97 visits per hour. The chicks were fed predominantly the grasshoppers and insect eggs, moths and occasionally the caterpillars and young lizards. Over the nestling phase the daily proportion of fecal sacs swallowed by parents decreased with a reciprocal increase in proportion of fecal sacs disposed of by parents. Of the total 490 fecal sacs handled by the parents, 150 (30.61%) were swallowed and 340 (69.39%) were disposed of away from the nest. A hatching success of 85.71% and fledging success of 94.44% were recorded in the study.