The enigmatic Rothschild´s Swift (Cypseloides rothschildi): natural history, distribution, and seasonality

ARETA JI; DEPINO EA; NÚÑEZ MONTELLANO MG; MOSCHIONE FN

WILSON JOURNAL OF ORNITHOLOGY

WILSON ORNITHOLOGICAL SOC

Año: 2020 vol. 132 p. 690 - 702

1559-4491

Rothschild?s Swift (Cypseloidesrothschildi) is among the least known South American swifts.Here we clarify its distribution, seasonality, and provide detailed naturalhistory data and breeding information. We compiled 197 records of Rothschild?sSwifts (museum specimens, citizen science initiatives, literature, and fieldobservations) all from Argentina and Bolivia; most from the breeding season(October?March, 177 records; 44 documented), a few thought to be on migration(April and September, 15 records; 3 documented), and less during thenon-breeding period (May?August, 5 records; 1 documented) with no records fromJuly/August. Rothschild?s Swifts are migratory, but the wintering quartersremain unknown. The distribution during thebreeding season is broadly overlapping with the Austral Yungas of Argentina andBolivia, with sparse records in Andean and extra-Andean ranges with forestedand non-forested waterfalls. Ourbreeding distribution model indicated high presence probabilities in theAustral Yungas of Bolivia and Argentina. Thebreeding season during the Austral Spring and Summer (late October/mid-November to mid-March/early April in northwestArgentina) began roughly with theearly rains as in other Neotropical swifts. Our data from 8 breeding sites and from 8 nests thatwe studied in northwest Argentina regarding nest placement (near waterfalls),nest features (moss or moss and mud cups), eggs (single and white), and on theprotracted development of Rothschild?s Swift nestlings (~55?60 d) and thesequence of plumage acquisition and behavior were coincidental with what isknown from other Cypseloides.We provide behavioral information from a momentarilycaptive individual which provided the first sound-recordings ofnestling/fledgling vocalizations of Rothschild?sSwift; presumably the first available for any Cypseloides. It is unclear whether these vocalizations, recordedin captivity, represent developmental precursors of adult sounds or beggingcalls. <!-- /* Font Definitions */@font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-536870145 1107305727 0 0 415 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-520092929 1073786111 9 0 415 0;}@font-face{font-family:"Arial Unicode MS";panose-1:2 11 6 4 2 2 2 2 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-134238209 -371195905 63 0 4129279 0;} /* Style Definitions */p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-parent:"";margin:0in;margin-bottom:.0001pt;mso-pagination:widow-orphan;font-size:12.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Arial Unicode MS";border:none;}span.Ninguno{mso-style-name:Ninguno;mso-style-unhide:no;mso-style-parent:"";mso-ansi-language:ES-TRAD;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:10.0pt;mso-ansi-font-size:10.0pt;mso-bidi-font-size:10.0pt;mso-fareast-font-family:"Arial Unicode MS";border:none;}.MsoPapDefault{mso-style-type:export-only;}size:8.5in 11.0in;margin:1.0in 1.25in 1.0in 1.25in;mso-header-margin:.5in;mso-footer-margin:.5in;mso-paper-source:0;}div.WordSection1{page:WordSection1;}