HOST RELATIONS OF PARASITIC COWBIRDS 



203 



Since the last addendum to the known fosterers (Friedmann, 1949, 

 pp. 154-157), 24 additional species and subspecies of birds have been 

 found to be parasitized by this cowbird, bringing the corrected total 

 up to 193 forms. The new hosts are listed below. 



pyrrhophia pyrrhophia 



Cranioleuca 

 (Vieillot) 



Aslhenes baeri baeri (Berlepsch) 



Sakesphorus bernardi bernardi (Lesson) 



Xolmis cinerea (Vieillot) 



Muscigralla brevicauda Lafresnaye and 

 d'Orbigny 



Pitangus sidphuratus maximiliani (Ca- 

 banis and Heine) 



Thryothoriis super ciliaris superciliaris 

 Lawrence 



Troglodytes viusctdus tobagensis Law- 

 rence 



Mimus longicaudatus albogrisevs Les- 

 son 



Turdus falklandii magellanicus King 



Vireo flavoviridis griseobarbatus (Ber- 

 lepsch and Taczanowski) 



Dacnis cayana cayana (Linnaeus) 

 Dendroica petechia riificapilla (Gnielin) 

 Macroagelaius subalaris imthurmi 



(Sclater) 

 Icterus bonana (Linnaeus) 

 Icterus chrysocephalus (Linnaeus) 

 Icterus grace-annae Cassin 

 Icterus chrysater giraudii Cassin 

 Icterus jamacaii croconotus (Wagler) 

 Pezites militaris belUcosa (Filippi) 

 Pheucticus chrysopeplus chrysogaster 



(Lesson) 

 Oryzoborus angolensis angolensis (Linn- 

 aeus) 

 Aimophila strigiceps dabbenei (Hell- 



mayr) 

 Zonotrichia capensis subtorquata Swain- 

 son 



In addition to the above, some other birds previously known as 

 fosterers of one race of the parasite, have now been found to serve in 

 this manner for other races as well. To simplify matters, we may 

 list the new hosts by subspecies of the cowbird before considermg them 

 individually. 



The following are additions to the recorded victims of the nominate 

 form of the cowbird, M.h. bonariensis, bringing its list of known hosts 

 up to 122 forms. 



Cranioleuca pyrrhophia pyrrhophia 



(Vieillot) 

 Asthenes baeri baeri (Berlepsch) 

 Xolmis cinerea (Vieillot) 

 Pitangus sulphuratus maximiliani (Ca- 



banis and Heine) 

 Turdus falklandii magellanicus King 



The Ecuadorian race of the shiny cowbird, Al.b. aeqnaforialis, 

 none of whose hosts previously have been recorded by me, has recently 

 been found to parasitize the following eight birds. 



Oryzoborus angolensis angolensis (Linn- 

 aeus) 



Aimophila strigiceps dabbenei (Hell- 

 mayr) 



Zonotrichia capensis subtorquata Swain- 

 son 



Sakesphorus bernardi bernardi (Lesson) 



Muscigralla brevicauda Lafresnaye and 

 d'Orbigny 



Thryothorus superciliaris superciliaris 

 Lawrence 



Mimus longicaudatus albogriseus Les- 

 son 



Vireo flavoridis griseobarbatus Berlepsch 



and Taczanowski 

 Icterus grace-annae Cassin 

 Pezites militarus bellicosa (FilipiM) 

 Pheucticus chrysopeplus chrysogaster 



(Lesson) 



