Records of the Lesser Spotted Eagle (Aquila pomarina) nests with two fledged young without human intervention in Slovakia

Abstract

Acknowledgement:The authors would like to thank to Ladislav Bohačík, Andrej Dúbravský, Richard Galáš, Stanislav Harvančík, Dušan Karaska, Ján Kicko, Miroslav Lehocký, Metod Macek, Jozef Mihók, Vladimír Pečeňák, Leonidas Prešinský, Radovan Reťkovský, Slávka Siryová, Ladislav Šnírer, Karol Šotnár, Oldřich Šreibr, Josef Vrána and Peter Vrlík for co-operation and information on productive Lesser Spotted Eagle pairs, which fledged 2 young without human intervention.

Population size, dynamics and reproduction success of the lesser spotted eagle (Aquila pomarina) in Latvia

“…This decline can probably be explained once again by a greater amount of available data. This ratio is similar to Estonia (1.86%, Väli 2012), but smaller than in Lithuania (2.4%, Treinys 2009) or in the Slovak Republic (3.61%, Maderič et al 2008).…”

“…In Germany -the westernmost part of the range of the species -an ongoing decline in pairs/present was established (up to 23% in the period from 1993-2007). This negative trend was related to the ongoing fragmentation and destruction of suitable habitats as well as human disturbance in breeding home ranges (Meyburg et al 2008, Böhner & Langgemach 2004, Langgemach & Böhner 2011. Corresponding to the significant decline in the number of breeding pairs in Germany, there has also been a steady Fig.…”

“…loss of suitable habitat. Since 1800 it is estimated that 90% of suitable habitats in Germany have been destroyed (Meyburg et al 2008). In the state of Mecklenburg-Pomerania (which has the largest proportion of the LSE population in Germany) between 1970 and 2001 about 7.7% of suitable habitats were destroyed (Scheller et al 2001).…”

The second egg in the lesser spotted eagle (Clanga pomarina) clutch as a nesting insurance

“…Obligate siblicide reduces these species' brood size to one in virtually all (˃ 90%) cases, and food stress was never found to be the proximate cause of this behaviour in any season (Gerhardt et al 1997). Although the complete lesser spotted eagle clutch consists mostly (81%) of two eggs, sometimes (16%) of one egg, and, in exceptional cases (2%) of three eggs (n = 178, Meyburg 1969), the percentage of nests found with two fledged young ranged from only 0.1% in Germany (Meyburg et al 2008(Meyburg et al , n = 1305 to 3.6% in Slovakia (Maderič et al 2008(Maderič et al , n = 1775. The interval from when the female laid her first to her second egg, calculated from the timing between when they hatched, would reach three to four days (Meyburg 1970, Sládek 1959) and occasionally up to six days (Meyburg 2002).…”