South Africans are being called on to become citizen scientists this weekend as conservationists revive the country’s first national crane census in two decades, hoping to uncover the true state of the iconic birds amid worrying declines in some populations.

The four-day count, running from Friday to Monday, comes as South Africa’s national bird, the blue crane, has been uplisted to vulnerable after its numbers fell by almost 40% since 2010.

The Endangered Wildlife Trust (EWT) and the International Crane Foundation (ICF) have revived the National Crane Census, last held annually between 1998 and 2006, to update population estimates and map the distribution of the country’s crane species.

The information will help scientists verify whether apparent population trends are accurate and guide future conservation efforts.

South Africa's three crane species — blue, wattled and grey crowned cranes —  tell different stories. While targeted conservation work has helped the endangered wattled crane recover in parts of KwaZulu-Natal, the country’s endemic blue crane has suffered sharp declines. Conservationists need a clearer picture of where all three species are thriving or disappearing.

Lara Fuller, the Drakensberg project manager of the African Crane Conservation Programme, said the crane census was being restarted, using modern technology — in this instance WhatsApp — to make it easier than ever for people across the country to participate.

Fuller said the EWT and the ICF partnership had been working on crane conservation alongside Ezemvelo KwaZulu-Natal Wildlife, the KwaZulu-Natal Crane Foundation and Eskom for the past 30 years. The collaborations had resulted in significant advances in crane conservation across the country.

“Crane conservation in South Africa relies on the information submitted by landowners and the public in order to monitor numbers and localities of all three species. You are our citizen scientists.

“We are, therefore, calling on all South Africans to assist us in this important citizen science initiative to verify whether observed increases and declines in crane populations are accurate. By working together, we can better understand these trends and contribute to meaningful conservation action.”

She said each crane species had unique ecological requirements and expanding  understanding of the needs was essential for their long-term survival.

The EWT said the Drakensberg was a global hotspot for the three crane species, which were regarded as flagship species for conservation and indicators of healthy wetlands and grasslands. They faced growing threats from habitat loss caused by mining, development and land-use changes as well as collisions with powerlines and other infrastructure.

It said cranes were among the world’s most culturally significant birds, including in South Africa. They were widely associated with longevity, wisdom, fidelity, peace, vigilance and hope, making them “powerful ambassadors for both natural and cultural heritage”.