Montagu's Harrier

Here the details of the Montagu's Harrier named bird below:

SCI Name:  Circus pygargus
Protonym:  Falco Pygargus Syst.Nat.ed.10 p.89
Taxonomy:  Accipitriformes / Accipitridae / Circus
Taxonomy Code:  monhar1
Type Locality:  Europe = England, ex Albin.
Author:  Linnaeus
Publish Year:  1758
IUCN Status:  Least Concern

DEFINITIONS

CIRCUS
(Accipitridae; Ϯ Western Marsh Harrier C. aeruginosus) Gr. κιρκος kirkos  partly mythical hawk, named for its circling flight  < κιρκος kirkos  circle, mentioned by many classical authors and later identified with the Hen Harrier (cf. κιρκη kirkē  bird referred to by Aelianus, different to κιρκος kirkos but not otherwise identified); "BUSARD. Circus.  { Le bec courbé dès la base; la tête plate en dessus, et garnie de plumes; la base du bec recouverte d'une cire; les ailes très-longues; la première penne de l'aile, très-courte; le tarse long et grêle." (de Lacépède 1799); "Circus Lacépède, Tabl. Ois., 1799, p. 4. Type, by subsequent designation, Falco aeruginosus Linné. (Lesson, Man. d'Orn., 1, 1828, p. 105.)" (Peters, 1931, I, p. 264).
Var. Cercus.
Synon. Eucircus, Glaucopteryx, Melanocircus, Polyborus, Pseudocircus, Pterocircus, Pygargus, Spilocircus, Spizacircus, Strigiceps.

circus
Gr. κιρκος kirkos  partly mythical hawk, named for its circling flight  < κιρκος kirkos  circle (syn. Circus aeruginosus).

pygargus
● Gr. πυγη pugē  rump; αργος argos  white, shining (syn. Apus caffer).
● Late Med. L. Pygargus Belon’s 1555, name for the Hen Harrier Circus cyaneus (the distinctions between the Hen Harrier and Montagu’s Harrier not having then been made)  < L. pygargus  type of eagle  < Gr. πυγαργος pugargos  hawk with a white rump, a bird of prey mentioned by Aristotle, Pliny and Hesychius, not further identified, but since associated with a variety of eagles as well as the harrier. A second sp. also known by this name and referred to by Aristotle has been linked with three different waterside birds: dipper Cinclus, wagtail Motacilla, and sandpiper Tringa; "41. FALCO.  ...  Pygargus.  9. F. cera flava, corpore cinereo, abdomine pallido maculis oblongis rufis, oculorum orbita alba.  Pygargus. Alb. av. 2. p. 5. t. 5. femina: & 3. p. 3. t. 3. mas. Raj. av. 17. n. 5.  Habitat in Europa." (Linnaeus 1758). This epithet is the fifteenth name in avian nomeclature (Circus).
● Gr. πυγαργος pugargos  hawk with a white rump  < πυγη pugē  rump; αργος argos  white; ex “Bald Eagle” of Catesby 1731, and “Aigle à tête blanche” of d’Aubenton 1765-1781, pl. 411 (syn. Haliaeetus leucocephalus).

Pygargus
(syn. Circus Ϯ Hen Harrier C. cyaneus) Gr. πυγαργος pugargos  hawk with a white rump  < πυγη pugē  rump; αργος argos  white (cf. specific name Falco pygargus Linnaeus, 1758); "XXIV. Gattung.  Bastarteule. Pygargus.  ...  Die Bastarteule hält das Mittel zwischen den Falken und den Eulen.  ...  Es gibt nur eine Art.   54. Ungleiche Bastarteule. Pygargus dispar.  ...  Falco cyaneus. Gmel. Linn. S. I. p. 276. n. 10. = Bechst. orn. T. p. 25. = Meyers und Wolfs T. p. 25.  Falco Pygargus. Gmel. Linn. S. I. p. 277. n. 111. Ein Weibchen." (Koch 1816); "Pygargus Koch, Syst. Bair.[sic] Zool., 1, p. 127, July, 1816—type, by monotypy, Pygargus dispar Koch = Falco cyaneus Linnaeus." (Hellmayr & Conover 1949, XIII, 218).