Comments about the geographic variations of Short-toed Eagles

by G. Dementiew
(From the Moscow University Zoological Museum)
The Short-toed Eagles from Turkestan are on average bigger than their relatives from other parts of the Palaartic region. The wingsize varies from 542 to 580 mm (male) and 561 to 605 mm (female) (on average 552,1 and 579,3 mm). The wingsize of the investigated Short-toed Eagles from European Russian, Kaukasus and Siberia deviates from 520 and 552 mm (male) and from 520 to 568 mm (female) (on average 532,4 and 539 mm; one time 513 and one time 570 mm (female).
Birds from Central Asia seem to have greater dimensions than the Europeans; a male from Huan-Che, captured by N. M. Przewalski in 1874, has an wingsize of 553 mm, another exemplar – from Mongolia (Gudzhirte, Kentei-Gebirge, 1. VI. 1925) – of 552 mm.
Some pieces of the Short-toed Eagle from India show remarkable small size; (this fact was mentionend by Dr. E. Hartert “V. P. F.”); a male from nepal in the museum of St. Petersburg (collectet by Captain Pirwill, traded by the British Museum) had for example a wingsize of only 473 mm. It’s a pity that those dwarves are not mentioned in the great work of E. Stuart Baker about Avifauna Indiens. (cf. vol. V, 1925, S. 94). He indicated a wingsize of 520 to 566 mm (male) and 530 to 571 mm (female) for the Indian Circaetus gallicus, the same as in European specimens.
There are no differences in the coloration between Turkestan Short-toed Eagles and birds from other regions, who are occupied by this form. You have to see the bright white-bellied form (Accipiter hypoleucus Pallas – “Z. R. A.”,I,1811, S. 354 – “in Rossia australo, circa Tanain et Volgam inferiorem” etc. ) only as a phase or type of individual Variation (sensu Menzbier) and not as a geographical race. On the other side you got to realize, that the race of Short-toed Eagles from Turkestan is bigger than those from European Russia, Kaukasus and West Siberia (birds from SW-Siberia are small, a male from Pavlodar has a wingsize of 520 mm, a female from Barnaul 546 mm).
I call the new geographical race
Circaetus gallicus heptneri subsp. nova.
(to honor my friend Dr. W. Heptner, the tireless investigator of the Turkestan fauna).
Typus. female ad., 23 III. 1927, Pischbek/Semiretschje, D. P. Dementiew leg.;
Cotypus. male ad., VI 1926, Brugun River near Tschimkent, S. P. Naumov leg.; in the Zoological Museum of the University of Moscow.
The new form lives in the whole Russian Turkestan, from the northern parts of Semiretschje (Kopal) and Syr-Darja-Area to the southern parts of the Fergena (Gultscha) and Buchara (Kuljab, Kurgon-Tjube). The exact border of distribution in the east is still to assert (compare with the specimens from China and Mongolia).
Described by 12 specimens (9 male and 3 female), compared with 26 birds of nominate form, which are kept in the Zoological Museum of the Academy of Science in St. Petersburg and in the Zoological Museum of the University of Moscow.
Translation to English by Stefan Jais, also we express our thanks to Markus Jais for his help.