Rhynchotus Rufescens Is Known Only Mountainridges in the Easternandes of Bolivia and from a Small Number of Museumspecimens
Total Page：16
File Type：pdf, Size：1020Kb
July1996] ShortCommunications andCommentaries 695 SHARP,D. E., AND J. T. LOKEMOEN.1987. A decoy choice in Mallards (Anas platyrhynchos).Behav- trap for breeding-seasonMallards in North Da- iour 115:127-141. kota. Journal of Wildlife Management 51:711- WEIDMANN,U., AND J. DARLEY. 1971. The role of the 715. femalein the socialdisplay of Mallards.Animal TITMAN,R. D. 1983. Spacingand three-bird flights Behaviour 19:287-298. of Mallards breeding in pothole habitat. Cana- dian Journalof Zoology 61:839-847. Received11 April 1994,accepted 5 September1994. WEIDMANN,U. 1990. Plumage quality and mate The Auk 113(3):695-697, 1996 Distinctive Song of Highland Form mact•licoIIfsof the Red-winged Tinamou (Rhynchotus rulescerts):Evidence for SpeciesRank SJOERDMAIJER • Ter Meulenplantsoen20, 7524 CA Enschede,The Netherlands The highland subspeciesmaculicollis of the Red- Rhynchotusrufescens maculicollis occurs on grassy winged TinamouRhynchotus rufescens is known only mountainridges in the easternAndes of Bolivia and from a small number of museumspecimens. No life northwesternArgentina at 1,000to 3,500m (Fjeldsl history data have been published. Herein I describe and Krabbe 1990). The other subspeciesof this bird the highly distinctivesong of this form. The songwas are widely distributed in grasslandhabitats south of a mysterioussound that I heard and tape recordedin the Amazon, from extreme southeastern Peru to cen- severallocalities in the BolivianAndes. I finallytracked tral Argentina,mostly in the lowlandsbut alsoin the down a singing bird in December 1993, near Inqui- highlands of easternBrazil (Sick 1993). sivi, departamentoLa Paz, Bolivia. A sonogramfrom Inquisivi and sonogramsof two different birds recorded near Vallegrande, departa- mento SantaCruz, are shown in FiguresIA, B, C. The E-mail: [email protected] songis aptly describedby the localname of the bird, 3 kHz t2 -•1 A T • B c 00 01 02 03 04 05 0 • Seconds 80 81 02 83 84 Seconds 00 0.1 02 o3 04 05 Seconds t2 00 01 02 03 04 05 oB 07 00 09 10 Seconds 1'5 2'0 2:5 Fig. I. Songsof Rhynchotus(rufescens) maculicollis (highland "race")and R. r. rufescens(one of three lowland races)recorded in Bolivia. Values for indicated variablesare given in Tables 1 and 2. (A) maculicollis,Inquisivi, departamentoLa Paz (16ø52'34"S,67øI 1'42"W; 3,500 m), 12 December1993; (B) and (C) maculicollis,Vallegrande, departamentoSanta Cruz (18ø39'30"S,63ø55'30"W; 2,400 m), 4 February1993; (D) r. rufescens,Serranla de Huanchaca,departamento Santa Cruz (14ø43'S,60ø30'W; 500 m), 19 April 1993. 696 ShortCommunications andCommentaries [Auk,Vol. 113 Data on durations and frequenciesof maculicollis songsare given in Table 1. The two songnotes vary conspicuouslyin "shape" (Figs. 1A, B, C) . The dif- ferencebetween songs of the two individualsrecord- ed at Vallegrande(Figs. lB, C) is especiallynoticeable, even more so becausethey were neighbors,taped on the samerecording. Even so, all maculicollissongs fol- low the samegeneral pattern of two short notes,the first modulated and the second "flat" and less loud than the first. The three other subspeciesof R. rufescenshave a different songfrom that of maculicollis;an exampleis shownin Figure 1D. The first note of this songre- semblesthe first note of the maculicollissong in being loud, short,and similarly modulated.The remainder of the songis strikingly different, however; instead of a short note immediatelyafter the first one, there is a long pauseof up to I s, followed by three mel- ancholic whistles (the secondof which is short). This songis describedaptly by the Portuguesephrase "Eu, nunca mais" (Sick 1993). This song is the same throughout the extensiverange of the three other Fig. 2. Map of Bolivia with four highland locali- subspecies(Narosky and Yzurieta 1989,Straneck 1990, ties where songsof Rhynchotus(rufescens) maculicollis Hardy et al. 1993,Sick 1993).I alsoheard this song recorded. Known distribution area is shaded. in variouslocalities in the departamentoof SantaCruz, Bolivia. "huayco," usedboth in the Inquisivi area and in the Data on durationsand frequenciesof thesesongs southern departamentoof Tarija. The song carriesa are listed in Table 2. As in maculicollis,the "shape"of long distance. When the bird sings from a grassy the four song notes varies considerably.Also as in mountain ridge, the song is audible throughout the maculicollis,I heard songdifferences between birds in valley below. the samelocality at the same time. Apart from the I also have tape recordingsfrom near Sorata,de- obviousdifference in "melody" between highland partamentoLa Paz, at the northern end of the Cor- and lowland songs,there alsoseems to be a difference dillera Real, and from southeastof Padcaya,depar- in loudness.As indicatedearlier, the song of macu- tamentoTarija, within 25 km of the Argentinean bor- licollisis far-carrying.The sound may seemto come der. Theserecordings indicate that maculicollishas the from quite nearby,but the bird actuallymay be 2 km samesong type all along the easternBolivian Andes away. My impression is that the lowland song is (Fig. 2). It is highly probable that birds in north- weaker,but I never actuallylocated a singing bird. western Argentina have the same song as well, al- The difference in song loudness,if real, could be though morphological differences between speci- explainedas an adaptationto an overall differencein mensfrom Tucumhn,Argentina and from terratypica populationdensity. The highland subspecieslives on in Bolivia suggestdifferentiation of local populations grassyridges, which often are rather narrow (with (Fjelds•and Krabbe 1989). eachbird occupyinga considerablestretch of ridge) TABLE1. Songparameters for Rhynchotus(rufescens) maculicollis from variouslocalities in Bolivia(see Fig. 1A for parameterdefinitions). Each row containsdata from a single bird; n is numberof songsused for measurements.Data are means(range in parentheses).All songsrecorded by author exceptat Sorata (recordedby Rolf de By).a Length (ms) Frequency(Hz) Location n t I t2 T fl f2 f3 Sorata 1 193 416 474 2,050 3,500 1,800 Inquisivi 13 183 (174-192) 303 (294-308) 396 (375-418) 1,960 2,900 1,640 VallegrandeA 2 188 215 417 (413-422) 2,050 3,350 1,950 Vallegrande B 1 147 317 529 1,950 2,400 1,900 Padcaya 2 185(155-215) 370 (360-380) 510 (470-550) 2,400 3,200 1,850 Recordingdata: Sorata, departamento La Paz (1Sø46'S,68ø3S'W; >-2,700 m), 21 December1991; Inquisivi, departamento la Paz (16ø52'34'S, 67ø11'42'W;3,500 m), 12 December1993; Vallegrande, departamento Santa Cruz (18•39'30•S, 63ø55'30'W; 2,400 m), 4 February1993; Padcaya, departamentoTarija (21ø54'S,64ø34'W; 3,3S0 m), 17 October 1992. July1996] ShortCommunications andCommentaries 697 TAI•I•E2. Songparameters for lowland subspeciesof Rhynchotusrufescens from three widely separatedlocalities (seeFig. 1D for parameterdefinitions). One song measuredat each locality. Length (ms) Frequency(Hz) Location tl t2 T fl f2 f3 f4 f5 Bahia, BraziP 180 1,160 2,220 2,050 3,200 2,100 2,300 2,000 Huanchaca, Bolivia b 220 1,060 2,180 1,800 2,900 2,000 2,050 1,800 Entre Rios, Argentinac 300 1,100 2,050 1,700 2,700 2,200 2,200 1,800 ßSubspecies catingae or rufescens;recorded Capita Grosso, 24 January1974, by JacquesVieillard (Hardy et al. 1993). * Subspeciesrufescens; recorded Serrania de Huanchaca,departamento Santa Cruz (14ø43'S,60•30'W; 500 m), 19 April 1993,by author. • Subspeciespallescens; recorded P. N. E1Palmar, October,year unknown (Straneck1990). and far away from the next ridge on the other side Acknowledgments.--Ithank Jon Fjeldsfifor his con- of the valley. Thus,the birds typicallylive quite far tinuous encouragementand support, sharing of his apart. Another indication of its low density is that I vast knowledge and experience,and good humor. I never heard more than two singing maculicollisat the thank Michael Friggens for introducing me to the sametime, and usuallyonly one. Lowland popula- wonderful habitatsnear Inquisivi. I alsothank Torben tionsoccur in muchhigher densities.Sick (1993) wrote Dabelsteenand Pout Hansen for help in preparing that they were "formerly abundant"in suitablehab- the sonograms. itatsin Brazil.My own experiencein suitablehabitats in Bolivia is that, more often than not, severalsinging birds are heard at the same time. The louder song of LITERATURE CITED maculicollis would facilitate communication with its rivals (and with prospectivemates). BI_•KE,E.R. 1977. Manual of Neotropical birds, vol. The songsof mosttinamou speciesare surprisingly 1. University of ChicagoPress, Chicago. uniform (Hardy et at. 1993).The songdifferences be- FJELDS,•,J., ANDN. KRAI•I•E.1989. An unpublished tween maculicollisand the lowland populationsof R. majorcollection of birds from the Bolivian high- rufescensare asgreat as between closely related species lands. ZoologicaScripta 18:321-329. in other tinamou genera (pers. obs.). Although in- FJELDS•,J., ANDN. KI•I•I•E. 1990. Birdsof the High dividual songsvary (Figs. 1A, B, C), this variation is Andes. Zoological Museum, Copenhagen and minor comparedwith the difference between low- Apollo Books,Svendborg, Denmark. land and highland populations.In my judgment,the GI•¾, G. R. 1867.2. Rhynchotus.List of Specimensof difference is too great to be consideredas dialectat. Birds in the Collection of the British Museum In Bolivia, the highland and lowland populations 5:102. appearto be separatedeverywhere by extensivefoot- H•,RV¾, J. W., J. VIEILLARD,AND R. StP•NECK. 1993. hill forests,and sympatryis not likely to exist any- Voices of the tinamous. ARA Records, Gaines- where. Judging from published distribution maps ville, Florida [cassettetape]. (Naroskyand Yzurieta 1989, Fjelds• and Krabbe 1990), NAROSKY,t., AND D. YZURIETA. 1989. Birds of Ar- highland and lowland populationsprobably are al- gentina and Uruguay. A field guide. Vazquez lopatric in Argentina also. Mazzini Editores, BuenosAires, Argentina. In the originaldescription of maculicollis,Gray (1867) PETERS,J. L. 1931. Check-list of birds of the world, treatedit as a separatespecies (in agreementwith the vol. 1. Harvard University Press,Cambridge, speciesconcept of that time). In accordancewith the Massachusetts.