What 6488 did last summer
Continuing our effort to fill in information from the adult Greater spotted eagle (6488) we have been tracking, I wanted to recap what it did during last summer. Although the eagle was an adult, it left Kuwait fairly late in the spring in 2020. When it left Kuwait, other Greater spotted eagles had already arrived on breeding grounds in Russia and started to nest. Anyway, the tracked eagle did not breed during summer 2020. After arriving on the breeding grounds (6 April), 6488 settled for some days near Turgay, Kazakhstan, then pushed farther north. For the rest of the summer it wandered widely in west Kazakhstan and southern Russia, sometimes settling for some days, even weeks. Its summer ranging lasted until 1 October (177 days). Its final weeks during the summer were spent close to Turgay, where its summer had started. The size of the summer range was huge, but the estimated size of the range depended on the way the data were analysed. Using a Brownian Bridge estimate of the home range, the eagle’s summer range covered more than 27,000 sq km; using a kernel density estimate the home range covered over 238,000 sq. km. See maps below.
Brownian Bridge estimate of summer range of an adult Greater spotted eagle in 2020.
Kernel density estimate of the summer range of an adult Greater spotted eagle in 2020.
The graph below shows the variation in movement during summer (orange), which contrasts with the steady movement during spring migration (green), and the settled behaviour during winter (blue)
Movement of an adult Greater spotted eagle during 2020. Orange is summertime, and shows the bird to be moving at times (e.g. in May), and being settled at other times (e.g. most of June).
The graph below shows the distance the eagle was from the starting point (Al Jahra) during the course of the year. During winter (blue) it remained close to the starting point; during spring migration (green) it moved quickly away from Al Jahra, and during summer (orange) it wandered around Central Asia, sometimes moving away from Kuwait and sometimes moving toward Kuwait.
