VAN RIJN S, VAN DEN BERG A, DE BOER P, DEKKER J, DEUZEMAN S, VAN STRAALEN D & KLEEFSTRA R (2019) Breeding White-tailed Eagles Haliaeetus albicilla in the Netherlands in 2006 to 2018. LIMOSA 92 (1): 3-15.

The White-tailed Eagle bred for the first time in the Netherlands in 2006. Until 2008 breeding was restricted to the Oostvaardersplassen. From 2009 onwards other wetlands were occupied (Tab. 2). In 2018 the population had increased to 14 occupied nests (Fig. 1). Observations of colour-ringed individuals showed that the first Dutch breeding birds originated from Northern-Germany, whereas most of the birds that settled in after 2012 were Dutch recruits (Tab. 1). White-tailed Eagles colour-ringed in the Netherlands mainly stayed in the country. Only few birds dispersed abroad but none of these have established a breeding territory yet (Fig. 4). Breeding success in 2006-18 amounted to 1.1 young per breeding attempt and 1.6 young per successful nest (Tab. 2). This is similar to reproduction numbers in surrounding countries. Chicks were sexed based on tarsus-index (Fig. 2) or ratio between weight and wing length (Fig. 3). In 38 young the sex-ratio was 50:50 (Tab. 3). First year survival was at least 60% and annual survival averaged 90% for the first 5 winters for birds born in 2007-12. Threats included (deliberate?) poisoning (2 poisoned birds were taken into captivity for recovery and subsequently released), shooting (one certain, one probable case) and collision with wind turbines (2 cases). Survival in the Netherlands, with an extremely high human population, does not seem to be lower compared to other countries. The slow and late recovery of the White-tailed Eagle population in Europe as compared with other raptor species, was probably due to low initial reproduction rate, limited dispersion distances and late age of first breeding of individuals.

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