Despite problems in other regions, some parts of Spain are seeing a rebound in eagle numbers
After years of decline in parts of Spain, the Bonelli’s eagle is now recovering in Catalonia, according to new research. In a study published recently in Ecological Applications, researchers examined a combination of factors, including immigration, deaths, births and emigration, to determine how the population in Catalonia has been doing over the years. Steep declines in the last two decades of the 20th century eventually stopped, and numbers in Catalonia began to recover in the 2010s. Immigration may have played a role in this increase—other recent research conducted in neighboring Valencia and Castilla-La-Mancha found that Bonelli’s eagles in those regions are not doing particularly well, due to a combination of electrocution on power lines and other human causes. “During the population’s decline, the arrival of immigrant individuals from other populations in the Iberian Peninsula in a better state was probably a relevant factor to prevent the decline from being greater,” said Antonio Hernández-Matías, a professor at the University of Barcelona and a coauthor of the study, in a press release. Retrofitted power cables and rebounding prey populations also contributed to recovery. But today, since the population in Catalonia has increased, migration into the region isn’t as important to the overall numbers. The authors still noted that the population is fragile, however, and still needs conservation attention.
