In new research, Jaume Adrià Badia‐Boher and colleagues highlight the need for long-term monitoring of conservation programmes. Here, co-author, Ana Sanz‐Aguilar demonstrates one success story of this nature, in conservation of the Canary Egyptian Vulture.
The population of one of the most endangered raptors in Europe, the Canary Egyptian Vulture (Neophron percnopterus majorensis), is recovering. This is one of the main conclusions reached by an international study analyzing the long-term effect of conservation actions applied within a LIFE-Nature project on the island of Fuerteventura. These are highly encouraging results because this bird had rather less hopeful prospects 20 years ago. The species was widespread across the archipelago in the early 20th century but in 1998 only 21 breeding pairs remained in a single population concentrated at Fuerteventura. At that point an intensive long-term monitoring programme started.
In order to plan conservation actions knowing the mortality causes of individuals that may driving the decline of an endangered species is essential. The first studies concluded that the dramatic decline experienced by the Egyptian vulture had been directly related with human activities, being the casualties due to power lines and the illegal poisoning the main causes of mortality. In this context, between 2004 and 2008 a European conservation project (LIFE) was implemented to reduce the main sources of mortality. In particular, education campaigns for public awareness and control of illegal poisoning to the modification of power lines to reduce the risk of accidents were implemented.
The Egyptian vulture monitoring programme carried out during the last 20 years has allowed us to evaluate the efficiency of the LIFE project beyond its 4 years of implementation. When dealing with long-lived species, long-term studies are required to properly evaluate changes in survival/mortality, the main factors determining population viability. Nowadays, 90% of the vulture population is individually marked and the monitoring of individuals allows us to evaluate the existence of changes in vulture survival after management actions through capture-recapture statistical methods. However, thanks to the intensive monitoring conducted at the study area, we realized that the rings used for individual identification deteriorate and become lost with time. To resolve this issue, we developed specific capture-recapture models accounting for ring loss that allowed to correctly estimate ring loss, survival and resight probabilities, and evaluate the efficacy of management actions.
Our results show that after the development of these LIFE project conservation actions, the survival of Egyptian vultures has increased, especially for adult and subadult birds. This may be the result of a drastic reduction in poisoning events that, in long-lived raptors, mainly affect territorial birds. Entanglements and collisions in power lines were also efficiently mitigated, although electrocutions persisted. The conservation of this critically endangered subspecies now faces a more optimistic scenario. The population tripled between 1998 and 2017, from 21 to 67 breeding pairs, and a new LIFE project focusing on reducing the electrocution mortality just started.
In conclusion, even in a scenario of maximum concern 20 years ago, a critically endangered species is recovering thanks to conservation projects focusing on infrastructures but also, and more importantly, on social conflicts. This study exemplifies how education and awareness campaigns can be especially effective for biodiversity conservation. Finally, this work highlights the extreme importance of long-term studies to evaluate the treatment and effectiveness of conservation actions, especially for long-lived species.
The full article, Evaluating European LIFE conservation projects: improvements in survival of an endangered vulture is free to read for a limited time in Journal of Applied Ecology.