Bagagahan and Matha-Adia: Colonial waterbirds heronries of Bhitarkanika National Park. ( One of Asia’s largest multispecies heronry)
Panoramic view of Bagagahan in Bhitarkanika | By Soumya.

Bagagahan and Matha-Adia: Colonial waterbirds heronries of Bhitarkanika National Park. ( One of Asia’s largest multispecies heronry)

Bagagahan heronry located in the sanctum sanctorum of the Bhitarkanika National Park is one of Asia’s largest and oldest mixed-species heronry in dense mangroves. Matha-Adia heronry located at an aerial distance of 800 m on the south of Bagagahan heronry is the newest heronry formed in 2012. Bhitarkanika National Park is located on the estuary of The Brahmani and the Baitarani river in the Indian state Odisha. The designated area of the Bhirakanika National Park is 145 square kilometres which was notified in the year 1998.  The park is famous for its estuarine crocodiles’ population and the avian fauna. These two heronries come to action on the advent of monsoon and thousands of waterbirds of different bird species nest together and raise their chicks until they fly.  

Asian Openbill Stork mating pair in Matha-Adia heronry.
Asian Openbill Stork mating pair in Matha-Adia heronry | By Soumya.
Asian Openbill Stork mating pair in Matha-Adia heronry.
Asian Openbill Stork mating pair in Matha-Adia heronry | Source: MFD Rajnagar.

What is a Heronry ?

Heronries are the ideal sites for the breeding population of herons, egrets and other waterbirds. Ecologically, heronries have a significant role in the conservation of waterbirds, as basically these sites fulfil almost all the requirements of colonial nesting of waterbirds providing them suitable and safe ground for feeding, roosting, perching, breeding and nesting.

In heronries of the Bhitarkanika National Park , multi-species colonies of waterbirds nest in large numbers on mangroves with the onset of monsoon in June – July and the entire nesting is over by mid-November. A total of ten waterbirds species have recorded being assembled for colonial nesting in Bagagahan and Matha-Adian heronries. 

Waterbirds nesting in heronries o of Bhitarkanika

The waterbird species nesting in these two heronries are as follows. Asian openbill stork (Anastomus oscitans)
Little Cormorant (Phalacrocorax niger)
Little egret (Egretta garzetta)
Intermediate egret (Egretta intermedia)
Large egret (Ardea alba)
Purple heron (Ardea purpurea)
Night-heron (Nycticorax nycticorax)
Grey heron (Ardea cinerea)
Oriental darter (Anhinga melanogaster)
Black-headed Ibis (Threskiornis melanocephalus)

Species composition and mean number percentage of waterbirds in both the heronries of Bhitarkanika. | Source: Pradhan and Kar, 2018.

Waterbird nesting trends in heronries of Bhitarkanika National Park.

Year-wise nesting trend of waterbirds in heronries of Bhitarkanika (2007-2016) | Source: Pradhan and Kar, 2018

Oriental darter chick perching on a nesting branch.
Oriental darter chick perching on a nesting branch | By Soumya.
Chicks of Purple heron eagerly waiting for arrival of mother.
Chicks of Purple heron eagerly waiting for arrival of mother. | By Soumya.

The highly productive detritus food chain of the mangroves provides and ensures the supply of food for the nesting waterbirds and their chicks for sustenance and survival. Due to serenity of virgin mangroves in Bhitarkanika attracts a large number of waterbirds to breed and nest in this sojourn. The extensive agricultural field surrounding Bhitarkanika National Park act as the primary source of food to these nesting birds and their chicks.

The nests were predated by jungle crows (Corvus macrorhynchos), house crows (Corvus splendens) White bellied sea eagles (Haliaeetus leucogaster), Water monitor lizards (Varanus salvator), and Burmese pythons (Python bivittatus) in these heronries. During the high tide, estuarine crocodiles (Crocodylus porosus Schneider) were found to be roamed on the inundated slushy ground in the heronries for preying on fallen chicks and fledgelings from the nests. 

Gradually, the number of waterbirds nesting in heronries of Bhitarkanika is increasing over the years. The Bhitarkanika is truly a paradise for birds and its protection is essential for the conservation of many bird species.

Best time to visit the heronry is August. The national park remains closed from May to July end for nesting of estuarine crocodiles.

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