1!<1)| (Iriniidl: Mammals ami I'.inh of llir Color>i<l„ \'alh 1/ ]:',<) 



Phalaenoptilus nuttalli nuttalli ( .\\i(\n\iiiu) 

 Niitlall l'(,or-uill 



Phalaenoptilus nuttalli nitidus I'.icwstr-r 

 Frosted I'oor-will 



l'(i<ir-\\ ills wiTc first iidtcd the cvcnintr of Fchniarv 2H at .Mcllcri; 

 tlicii .Mar-rli .',. at TIm- Xccdjcs; tln^ni'd'ortli at every one of our stations 

 all llic way down the river to I'ilot Knoli. .May 12. The mellow eall 

 was heard [)raetieally every ni^hl uhi'o the wind v\as not lilowinf,'. 

 As with the rii'„dith;iwks, the poor-wills a|i|H'i/rcd td spi-nd the day out 

 on the desert. Drif individual was flnslu'd o'-ar tllircnlHTL' i'nmi tln' 

 stony surface of a wa.sh in the shade of a jjalo verde. In the evening; 

 the birds appeared at dusk in the river bottom, alij^htinjr in eliarae- 

 teristie fashion on spaces of bare trround or in roads, not infrequently 

 on mud bars in the river, or skimmintc low over the water itself. 

 Their proneness to alijrht on the wet mud at the edjre of the water 

 was evidenced by the jjacked balls of mud firmly dried on the toes of 

 several of the birds shot. In the evening of April If), ci^dil inih-s east 

 of Picacho. fully a dozen poor-wills were tibserved. Thei-c was a lot 

 of broken-down fencintr close to the rivi-r near our c-ani|) at this point; 

 the birds congregated here as a basis lor foraging and consociating. 

 resting on the posts as well as on the pnjstrate poles, evidently in 

 preference to alighting on the sticky miKl of atj overflow ilcprcssion 

 on the one hand or the river margin on llie othi r. 



The series of eighteen specimens of this bird .secured at once aroused 

 inquiry because of the large range disjjlayed in size and pattern of 

 coloration. Even in the field, as the specimens were collecti-d. con- 

 spicuous differences were noted and the suspicion aroused that really 

 two subspecies were represented, one being the resident breedinir form. 

 the other a winter visitant. The first elue to discrimination came 

 through observing the state of activity of the reproductive organs. 

 Of two birds shot the same evening at Riverside Mountain, one, no. 

 12780, with tastes small, was relatively large, dark, and coarsely 

 marked; the other, no. 12781, with testes very large, was small in L'lri- 

 eral size, narrow-barred, and notably pale. In five other l)irds, ii<id 

 e.xamination showed the .same relative state of affairs (see accompany- 

 ing tables). It is of course regrettable that state of reproductive 

 activity was not recorded of all the poor-wills taken. 



The seven birds, dis.seeted in the field by the writer, would ser-ni 

 to provide adequate basis for the conclusion that two races were repre- 



