Protecting threatened Over-seas biodiversity

Reproduction of the Madagascar pond-heron : Review 2020-2021

The mangroves of the island of Mayotte are particularly rich ecological environments. You can observe the most endangered bird species in this area: the Madagascar pond-heron. The 2021-2022 breeding season of the Madagascar pond-heron will start soon, the opportunity to take stock of the monitoring of this species by the GEPOMAY as part of Life BIODIV ‘OM project.

Monitoring and identification of Madagascar pond-heron nests within the heronries © GEPOMAY

2020-2021 review: an increase to be put into perspective

No less than 281 pairs were recorded over the 2020-2021 season, which is a larger observation than in previous years (2019-2020: 279 pairs; 2018-2019: 144 pairs; 2017-2018: 182 pairs). These numbers are still difficult to interpret and cannot be compared. Indeed, the Madagascar pond-heron monitoring protocol is constantly evolving and, again this season, new recommendations have been drawn up to improve it. The development of a precise protocol allows better observation of individuals, a reduction in bias and the assurance of obtaining comparable results from year to year thereafter.

Same conclusion with the results of the calculation of the reproductive success of this heron. The average reproductive success for the 2021-2021 season is 0.56 with 157 fledglings against 0.65 in 2019-2020 and 0.93 in 2018-2019. It is still unclear whether these figures are really down.

The main breeding site of the Madagascar pond-heron is Madagascar. This bird breeds only in 3 other islands in the world including Mayotte, a breeding ground therefore essential for the species. It is now certain that the protection actions of the Life BIODIV’OM project are relevant and necessary for the survival of the species.

Madagascar pond-heron © Gilles ADT