The Heronry Count focuses on nesting colonies of herons, egrets, and storks during their breeding season. BWS surveys provide insights into breeding success, population trends, and the conservation status of colonial waterbirds across the region. This initiative is led by Avijan Saha from Airavat (an NGO based in Siliguri), volunteers from BWS, Optopic & SPA.

Heronry Count 2025

AVIJAN SAHA

Introduction

This year, the annual heronry count was organised in the Naksalbari and Khoribari block areas on 13 July 2025 and 10 Aug 2025. Four organisations, including Airavat, Optopic, BWS and the Siliguri Photographers’ Association (SPA), jointly conducted this program in the Naksalbari region. We have been monitoring large heronry colonies in this region for the past four years, this being the fifth year.

Method

We divided the participants into two groups, with both groups starting their counts simultaneously. The late afternoon period was selected for counting, as herons typically return from their foraging zones during this time. We also conducted a secondary count after dark to confirm population estimates. The main counting session ran from 15:30 to 18:30 hrs. Before this, we surveyed two major foraging zones in the Naksalbari block—Mechi and Panitanki—using a fixed-point count method for two hours (13:00–15:00 hrs). Here, too, two separate teams were deployed to avoid double-counting.

Results

This fifth heronry count covered seven individual nesting trees in and around Naksalbari Bazar, as well as the Mechi riverbed, where herons, storks, and egrets were actively foraging.

Counted figures:

  • ✅ Black-headed Ibis (Threskiornis melanocephalus) – 370 individuals, including 85+ breeding pairs (nests
    distributed across 7 trees)
  • ✅ Red-naped Ibis (Pseudibis papillosa) – 17 individuals (Mechi and Naksalbari)
  • ✅ Lesser Adjutant Stork (Leptoptilos javanicus) – 3 individuals (Mechi)
  • ✅Asian Openbill (Anastomus oscitans) – 2 individuals (Mechi)
  • ✅Cattle Egret (Bubulcus ibis) – 70+ individuals in 5 trees (Naksalbari)
  • ✅Little Egret (Egretta garzetta) – 41 individuals, including 7 nests (Naksalbari)
  • ✅Intermediate Egret (Ardea intermedia) – 32 individuals, including 6 nests (Naksalbari)
  • ✅Indian Pond Heron (Ardeola grayii) – 23 individuals, including 4 nests (Naksalbari)
  • ✅Little Cormorant (Microcarbo niger) – 14 individuals, including 2 nests (Naksalbari)
Outcome

This year, the colonial distribution extended across seven trees, compared to five trees last year. The Blackheaded Ibis was the dominant species, over the Red-naped Ibis in this locality. These regular seasonal counts help us monitor population dynamics, nesting patterns and sites, foraging zones, and movement trends.Notably, the Black-headed Ibis was also recorded in the Fulbari wetland this year. Airavat documented around seven individuals there and tracked them up to Phansidewa.

Team Members

Led by Avijan Saha, members were drawn from – Airavat, BWS, SPA , Optopic including other individuals. The team list: Avijan Saha, Shekhar Pal, Santu Dutta, Mousumi Datta, Biswapriya Rahut, Dipprovo Majumdar, Debapratim Saha, Pran Gobinda Nag, Bimal Debnath, Sisir Debnath

Heronry Count 2024

Monitoring the Heronries of Darjeeling Terai

Assessment during 2024 heronry count, jointly conducted by Airavat Trust and the Birdwatchers’ Society:

  • ✅ Active breeding colonies of Black-crowned Night Heron, Cattle Egret, and Indian Pond Heron were monitored.
  • ✅ Reports from local birders and citizen scientists led to the discovery of five new heronry sites, many of them centered around community ponds.
  • ✅ The study underscored the critical importance of preserving breeding trees, particularly during pruning season—a finding shared with civic and forest authorities.

For the past five years, Airavat Trust has been actively monitoring heronries and tracking the seasonal movement patterns of key colonial waterbirds across the Darjeeling Terai landscape.
Since 2023, this initiative has been strengthened through support from the Birdwatchers’ Society, fostering a collaborative scientific effort to better understand the ecology and conservation needs of these last remaining strongholds of heronry colonies in the region.