The Spot-billed Pelican is a waterbird of South and Southeast Asian wetlands. It scoops fish near the surface into its bill pouch, drains the water, and swallows the fish.
Pre-breeding adults are grey above and white below, with a long grey-brown crest. Most facial skin and the eye-ring are orange-yellow, with bright purple skin in front of the eye. The bill sides and dull purple pouch have bluish-black spots. After breeding, the facial colours dull and the crest shortens. Juveniles are brown, with less distinct bill spots than adults.
At Kokkare-Bellur Community Reserve in Karnataka, southern India, researchers examined 41 adult Spot-billed Pelican carcasses collected from 2018 to 2022. After confirming sex, they measured ten features, including bill and wing dimensions, and compared 18 males with 23 females.
Males were larger in nine measurements, and bill lengths did not overlap in this sample. Each bird had a distinctive bill-spot pattern; photographs of wild pairs showed the same size difference. Male bills exceeded 337 mm and female bills measured below 320 mm.
An extinction-risk assessment has not been added yet.
Photographing bill spots at a colony can support repeated identification without capture. The authors suggest this approach for future behavioural studies.