Breeding biology of the Little Cormorant Phalacrocorax niger (Pelecaniformes: Phlacrocoracidae) in Bangladesh

Habibon Naher,Md Khalilur Rahman,Noor Jahan Sarker,Shawkat Imam Khan

doi:10.11609/jott.o1790.221-5

Abstract

The breeding biology of the Little Cormorant Phalacrocorax niger was studied in a nesting colony at Dhonagoda Village in Chandpur District, Bangladesh between 2003 and 2005. The breeding activities of the Little Cormorant commenced in May and continued till October. The major nesting trees of the colony included Albizzia procera, Mangifera indica, Ficus spp., Streblus asper and Cocos nucifera. Both partners took part in nest building (n=33). The nest building period was 8 to 15 days (meanï¿½ plus or minus SD 10.85ï¿½ plus or minus 1.98) and the clutch size (n=20) varied from 2 to 6 (3.75ï¿½ plus or minus 0.8). The length and diameter of the eggs (n=115) ranged between 4.05 and 4.98 cm (4.5ï¿½ plus or minus 0.18) and 2.5 and 3.03 cm (3ï¿½ plus or minus 0.07) respectively. The eggs weighed between 14g and 25g (18.4ï¿½ plus or minus 0.88). The incubation period was from 14 to 21 days (17.3ï¿½ plus or minus 2.1) and the weight of the hatchling varied from 4 g to 18.2g (10.45ï¿½ plus or minus 3.6). The brooding period was from 15 to 20 days (17.3ï¿½ plus or minus 1.26). The young flew away from the nest at the age of 17 to 29 days (20.85ï¿½ plus or minus 2.8) after hatching when the weight was 350g to 470g (411.93ï¿½ plus or minus 28.55). The breeding success was 78.76% in relation to eggs hatched and 68.26% in relation to eggs laid.

Highlights

The natural history of Little Cormorant Phalacrocorax niger is well known through a large number of anecdotal reports (Jerdon 1862; Whistler 1949; Wallace 1971; Ali 1977, Barnes 1981; Welty & Baptista 1988; Perrins 1990), very few research works on the breeding biology of the species exist (Sirriwannichkul 1981)
The study was conducted in a nesting colony at Dhonagoda Village near Dhonagoda River under the Upazila Matlab (North) in the district of Chandpur, Bangladesh
Breeding season The breeding of the Little Cormorant began in May and continued until October, similar to observations by Whistler (1949), Smythies (1953), Ali & Ripley (1968), Begum (1977), and Siriwannichkul (1981)

Summary

INTRODUCTION

The natural history of Little Cormorant Phalacrocorax niger is well known through a large number of anecdotal reports (Jerdon 1862; Whistler 1949; Wallace 1971; Ali 1977, Barnes 1981; Welty & Baptista 1988; Perrins 1990), very few research works on the breeding biology of the species exist (Sirriwannichkul 1981). For scientific management of the cormorant population and their conservation, it is imperative to study breeding ecology, survival, and mortality and factors that influence their breeding success. There exists no published information on the breeding biology of Little Cormorant in Bangladesh. In an attempt to fill this information gap, this study was conducted to understand the breeding biology of the Little Cormorant with emphasis on biometry of eggs and fledgling success in Bangladesh

MATERIAL AND METHODS

RESULTS AND DISCUSSION

CONCLUSION