AKT. 7 CAUDAL MOLT Of BIRDS FEIEDMAN]^ 3 



I find that most woodpeckers molt their rectrices centrifugally, 

 but a few, such as Oamipethera nubica nuMca, Dinopiumi javanensis 

 irdemnedia^ and Pious viridis viridis appear to have a centripetal 

 caudal molt. However, it should be noted that my observations are 

 made wholly on skins in the museum, not on living birds, and that 

 the cases of apparently centripetal ecdysis may well be all of the 

 type described above by Stone and also by Heinroth (12). How- 

 ever, Dendropicos fuscescens JiempricJiii and Thripias namaquus 

 have a regularly centrifugal molt. Stone's explanation, quoted 

 above, has a teleological flavor that need not concern us in this con- 

 nection, as this paper is meant merely to record certain facts and not 

 to advance or criticize any hypotheses concerning them. 



Van Tyne (4) does not mention whether Rhamphastos hrevicarina- 

 tics is the only toucan examined by him, or if he studied other species 

 as well and found them all to molt the tail feathers centripetally. I 

 have gone over the toucans in the collection of the United States 

 National Museum and found molting specimens of eight forms 

 other than the one studied by Van Tyne. The tail molt is centripetal 

 in RhanfYhphastos tocard^ Pteroglossus sanguineus^ Pteroglossus in- 

 scriptus, Selenidera spectaibilis, and Aulacorhynchus prasinus; it 

 appears to be irregular in Rhamphastos amhiguus, and centrifugal 

 in Rhcmiphastos erythrorhynchus. Heinroth (12) says that the molt 

 in the Rhamphastidae is centrifugal, but does not list the species 

 examined. 



The barbets, being among the closest relatives of the toucans, were 

 studied with unusual interest, and the following facts were ascer- 

 tained: A number of species have centrifugal tail molts, but an 

 equal number shed their rectrices centripetally, while some appear 

 to be irregular in their sequence. The order of rectrix renewal has 

 no systematic significance here (or in the toucans) as it has among 

 the pheasants, for it does not remain constant even within generic 

 limits. The following species molt their tail feathers centrifugally : 

 Lyhius gmfsohalito guifs6balito\^ THcholaema diadeinatunn diade- 

 matum^ and TTicholaeTna lacrymosum lacrymosum. Those with a 

 centripetal molt are Tricholaema tnelanocephalum stigniatothorax, 

 Trachyphonus darnmidii hohmi^ and Trachyphonus darnaudii usairir 

 hiro. Two species, Trachyphonus erythrocephalus jacksoni and 

 Trachyphonus margaritatus somalicus are irregular in this respect. 

 It may well be that more abundant material will show these to be 

 definite in their molting sequence and that they are comparable to 

 such cases as Pavo and the Argusianinae in the pheasants. 



The colies, being one of the best marked, systematically most iso- 

 lated groups of birds, present yet another character to help set 

 them off from all other avian families in the fact that apparently 

 all the species of the group molt their rectrices centripetally. The 



