ML67945

視聴覚メディア・ノート

NOTES: Neotropical Institute Cut # 89. Bulk reel: 386. Ascending whistles, then a display (30-40 seconds) edited out between bird's last whistles and its display. Quality: 2. Level: +3. 203 tape. LN. From bird's new position: one ascending whistle and then a display. Quality: 2. Level: +3. 203 tape. While on previous days, and especially on 13/III, the female, after first "appearing" after the male's first display, remained for some time in +/- the same site and the male displayed to and fro centering around her, today the female flew after (and apparently beyond the male each time he displayed and they thus very quickly moved toward their foraging (assumed) sites. This movement was in the same direction as on past days but some five minutes or more each one. Note: The recordings do not cover the complete activity by the birds, for inevitably some were lost while focusing and especially when it was necessary to move equipment close to the birds on new position. Note: As all the action was on the (R) channel, it has been re-recorded from N-IVS to N-4.2. 203 tape. Microphone: (L) EV 650, no parabola; (R) Senn 405, 36" parabola. P. argyrotis - notes of 18/III/74 - No recordings, but observations are of particular interest. First activity noticed was "series ascending whistles" in one of the customary trees, this one @ upper limit (east end) of the parking area below concrete bridge @ km 20.5. After a number of these, the bird changed to fairly loud "ao" calls with a rather "insistent" or "inquisitive" character. After some times of calling, it made a display flight to the east. At new position (= #2) bird again called "ao"; no whistles heard, then made display flight further toward east. Then repeat, back toward west, alighting close to #2 position. Then repeat and this time display again to west and flight continued to a bare tree ~ 150 m. to west. Bird called "ao," with same "inquisitive" quality, for a long time, then made a display flilght back toward east, alighting very close to its very first position. Therefore, both this and the previous one were much longer (more distant) than normal display flights. Also this westerly "foray" was well out of the bird's normal displaying area; the previous displays had been within its usual area. From the last perch bird took off in direction toward the #2 site and when almost there began a display which could not be fully developed due to the short distance remaining. By this time it was very light and observations ended. However, I don't recall why this ended so abruptly; probably because the male flew far away. Notes: 1) This bird takes off flying @ beginning, planes, and after 1(+?) seconds begins display. 2) Two or three of the displays were seen rather well from behind: the bird's wings beat from slightly above the horizontal to less than (certainly no more than) 45¡ below the horizon. 3) The final abortive display was made with very shallow wing beats: very slightly above the horizon to < 30¡ below. The sound was less "drummy" (although still partially so) and more "rattly." 4) As nearly as have been able to observe, during display the bird holds wings in a stiffly bowed position; during normal flight the primaries flex upward during the down stroke, as one might expect. Tentative interpretation: I think the behavior today indicated that the male couldn't locate the female., At no time did I hear a second bird nor the usual female responses, and apparently the male didn't either, so "went looking," using his wing-drumming display in this case either through "hormonal urge" or as an additional attempt to signal the female. (Although I don't recall (should check first recordings) that the female usually replies to the "series ascending whistles" of the male, perhaps she does.) Reason: after giving a number of whistles, this male changed to "ao" calls with a "querying quality." These are louder than the whistle and perhaps the male was trying to get a response so he'd kn