Science Snippets: Crane populations bounce back after concerted conservation effort in KwaZulu-Natal, South Africa

Erin Adams, Tamsyn Galloway-Griesel, and Lizanne Roxburgh, EWT Science and Planning Unit, erina@ewt.org.za 

South Africa is home to three of the four African Crane species. These include South Africa’s national bird, the Blue Crane (listed as Vulnerable on the IUCN Red List), the Grey-crowned Crane (Endangered) and the Wattled Crane (Vulnerable). The three crane species converge within the KwaZulu-Natal province of South Africa (see map), and crane populations declined severely in this region in the 1980s. And as a result, there have since been considerable conservation efforts focused there. Annual aerial surveys have been conducted in this region by the Endangered Wildlife Trust – International Crane Foundation partnership and Ezemvelo KZN Wildlife for many years to monitor crane population sizes. In a recent publication* co-authored by EWT scientists, the results of the long-term aerial surveys were analysed in relation to the conservation initiatives.

KZN Crane Distribution Map

As cranes’ deaths due to collisions and electrocutions with powerlines are common, particularly amongst young birds, markers were placed on powerlines in high-risk areas to improve visibility and reduce crane mortalities. Another major threat to cranes is habitat loss, and so protecting crane habitats has been one of the major interventions in KwaZulu-Natal. This was achieved by declaring new protected areas, getting willing landowners onboard to maintain crane habitats on their property and involving the general public to become “crane custodians”, who would report any powerline collisions and any crane nest disturbances they may come across. The extent of these initiatives was monitored over 15 years (from 2003 to 2018), along with monitoring crane population numbers with standardised annual aerial surveys to determine whether they increased due to these initiatives.

Within KZN, all three crane populations have slowly but steadily increased in size since 2003. These numbers are directly correlated with the conservation initiatives in the region. The protection of crane habitats has facilitated the return of cranes to previously disturbed areas but are now protected and maintained due to the work of crane custodians. A reduction in crane mortalities due to the increased visibility of marked powerlines has also been recorded.

The authors concluded that the conservation initiatives to conserve cranes in KZN have effectively increased the population numbers of these threatened species. It was not possible to determine which conservation initiative, in particular, was the most effective, but rather concluded that a combination of all of these interventions has allowed for an increase in the crane population sizes, and led to this conservation success story.

*Galloway-Griesel, T., Roxburgh, L., Smith, T., McCann, K., Coverdale, B., Craigie, J., Pretorius, M., Nicholson, S., Michael, M., Durgapersad, K., & Chetty, K. (2022). Evidence of the effectiveness of conservation interventions from long-term aerial monitoring of three crane species in KwaZulu-Natal, South Africa. Bird Conservation International, 1-16.