Paul A Schwartz
- Rancho Grande; Km 24.5
- 10.3666667 -67.6833333
- 1030 meters
- NAGRA III
- Electro-Voice 650
- Parabola 91.4cm (36in)
NOTES: Neotropical Institute Cut # 11. Bulk reel: 375.
Weather: Light Fog.
30 Mar 1968. 5:35 AM. One wing whir, the first heard this dawn (one voice). Quality: 3. Level: +10. Then voice note about this bird and display, etc. = roughly - display very shortly after takeoff; when takes off down hill, it sailed back to near point of start. Didn't react to one distant display but immediately after second it gave one of its own.
First flight today started from about same place.
Then after -3" (only part interval saved) there's another wing whir. This originated fairly close to me and bird glided down to where the other had gone. Therefore, it's either a different bird or the other had come back without my realizing it, which I doubt. Quality: 1-2. Level: +10.
Then voice note re: [above paragraph] and shortly another display down near the new position. Quality: 2. Level: +10.
During all this time I heard no vocalizations.
Note: There were no displays nor vocalizations heard here when checked again mid-May and early July (1968).
13 December 1968, Rancho Grande, Km 35+ (500 m.)
(See also Cut 9.)
~ 6:11 AM I heard calls from this species in this area when usually only P. purpurascens is found, P. argyrotis usually being only at higher altitudes. *These calls came from east ridge and then four birds glided across to mid-ridge and then over to west ridge.
One thing I noticed about the silhouette of the "planing" birds is that argyrotis doesn't have as pronounced a large planing surface all concentrated at rear as is case with purpurascens but has a more pronounced tail sticking out toward rear.
(See cut 12)