154 Annals of the Carnegie Museum. 



46. Rupornis magnirostris insidiatrix Bangs and Penard. 



Asturina magnirostris (not Falco magnirostris Gmelin) Sharpe, Cat. Birds 



Brit. Mus., I, 1874, 207 ("Santa Marta"). — Salvin and Godman, Ibis, 



1880, 176 (Santa Marta and Minca; habits; food). 

 Rupornis magnirostris Bangs, Proc. Biol. Soc. Washington, XII, 1898, 132 



("Santa Marta"). — Allen, Bull. Am. Mus. Nat. Hist., XIII, 1900, 129 



(Bonda) ; XXI, 1905, 280 (Bonda; descr. nest and eggs). 

 Rupornis magnirostris insidiatrix Bangs and Penard, Bull. Mus. Comp. Z06I., 



LXII, 1918, 36 ("Santa Marta Mountains"; orig. descr.; type in coll. 



Mus. Comp. Zadl.). — SwANN, Syn. List Acciptres, iii, 1920, ' inserted page 



(ref. orig. descr.).- 



Seventeen specimens : Bonda, Mamatoco, Don Diego, Punto Cai- 

 man, Tierra Nueva, Minca, Fundacion, and Dibulla. 



Comparison of the above series with another from French Guiana 

 and eastern Venezuela, typical of magnirostris, shows that the Santa 

 Marta birds represent a well-marked race, easily distinguishable by its 

 paler, purer gray coloration. Selecting specimens in fresh plumage 

 for comparison, we find that in true magnirostris the pileum and upper 

 surface in general are deep neutral gray, while in the new form these 

 parts are light neutral gray. There is a corresponding difference in 

 the color of the throat and breast, while the. posterior under parts are 

 not so heavily barred, the white predominating, and usually with less 

 rufescent shading, in insidiatrix. Fortunately our series of both forms 

 is sufficiently large to eliminate the factor of individual and age 

 variation, which is considerable in this species. The characters here 

 assigned, however, seem to hold good even for immature birds, mak- 

 ing due allowance for their peculiarities. 



Several examples from northern Venezuela show an approach to the 

 characters of this new form, but specimens from the interior of 

 Colombia are perfectly typical magnirostris. Not having seen birds 

 from the coast region of Colombia farther to the westward at this 

 writing, we are unable to say whether they belong here or not; if not 

 (as one may judge from the remarks of Dr. Chapman in his recent 

 paper), then the range of insidiatrix would be restricted to the Santa 

 Marta region. 



One of the most abundant of all the hawks of this region, where, 

 however, it is restricted to the lowlands and lower foothills of the 

 Tropical Zone, rarely straggling up to 2,000 feet. It is found in the 

 forest and open woodland, especially along streams, and is rather tame 



