C. Koford 1957 2 Zarhynchus wagleri 31 January 1957 Barro Colorado Is. Canal Zone Saw crossed over Chapman House in evening, stopping in balsa tree. Singing calls. ? much larger than ??. 19 February 1957 In p.m. Saw one nest lod bur started in jacaranda near SE corner of Test Table Bldg. Seems like all foundation work, about 12" off end of branch being wrapped in blackish fibers. 22 February 1957 In morning two nests at site, well started, the first above mentioned lying about 1 1/2 ft. long ?, upper part including foundation wrapping around branch. This called No. 1, about 20' above level of peak roof of Test Table Bldg. A second nest located 15' east of this = No. 2. Bag somewhat shorter. ?? seen to go into these nests carrying nesting material as late as 6 p.m. Mr. Nower observed nest No. 1 on Feb. 20. He saw at least 4 other nests in early stages. Occasionally ?? gave loud alarm call and all birds down into low foliage under nest. Used light colored fibers or tendrils, hose like in size, up to scuttle with side roots. 9:38-9:44 a.m. ? drove off giant con- birds visiting nest. Arrivals & departures instantaneous ? at No. 1 nest: Arr. 9:00 :04 :07 :09:14 1/2 :16 :18 1/2 :24 :29 :40 :49 :51;02 10 Dep. :02 :06 :08 :14 :15 :18 :21 :25 :31 :45 :50:51 1/2:10 Carried tendrils, balsa material, gum material, bark strips, root lets. On 3 trips nothing visibly carried to nest. Mr. Nower notes of February 21 (extracts): birds waking at 6:10 a.m., 5 working, especially 2. Stop work midday, resumed working on 2 nests in p.m., 4 birds leave before dusk. Considerable rolling of nest material from closest bird. Battles when bird returned to nest while being rolled.