Revelando un patrón complejo de variación del canto en Zonotrichia capensis australis en el este de Patagonia

Agustin I. Casale; Victoria Blanco; Pablo D. Lavinia; Darío A. Lijtmaer; Pablo L. Tubaro

doi:10.56178/eh.v41i2.1544

Articles Published 24 September 2026 https://doi.org/10.56178/eh.v41i2.1544

Revealing a complex pattern of song variation in Zonotrichia capensis australis in eastern Patagonia

acoustic adaptation regiolects Rufous-collared Sparrow song dialects vocal learning vocal variation

Agustin I. Casale División Ornitología, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’ (MACN-CONICET). Av. Ángel Gallardo 470, 1405 CABA, Argentina | Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina

Victoria Blanco División Ornitología, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’ (MACN-CONICET). Av. Ángel Gallardo 470, 1405 CABA, Argentina | Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina

Pablo D. Lavinia Laboratorio de Investigación y Conservación de la Biodiversidad (InCoBIO), Universidad Nacional de Río Negro (UNRN-CONICET), Sede Atlántica. Viedma, Río Negro, Argentina | CIT Río Negro, Universidad Nacional de Río Negro (UNRN-CONICET), Sede Atlántica. Viedma, Río Negro, Argentina

Darío A. Lijtmaer División Ornitología, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’ (MACN-CONICET). Av. Ángel Gallardo 470, 1405 CABA, Argentina

Pablo L. Tubaro División Ornitología, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’ (MACN-CONICET). Av. Ángel Gallardo 470, 1405 CABA, Argentina

Abstract

The Patagonian subspecies of the Rufous-collared Sparrow (Zonotrichia capensis australis) is the most morphologically distinct, lacking the typical black crown stripes. Previous studies in northeastern Patagonia had shown that songs include pretheme notes and lack a trill, but we have recently shown that this is not the case in southeastern Patagonia. In order to study vocal variation throughout eastern Patagonia, we recorded and analyzed the songs of about 500 Z. capensis individuals from Santa Rosa (La Pampa province) to Monte León National Park (Santa Cruz province). We detected three regiolects. The northernmost Espinal regiolect is replaced in Sierra Grande (Río Negro province) and between Punta Colorada and Puerto Lobos (Chubut province), by songs with an atypical structure, frequently including a pretheme and lacking a trill. This Northeastern Patagonia regiolect extends to approximately 100 km south of Trelew (Chubut province), where it is replaced by the Southeastern Patagonia regiolect with its more typical structure and different types of trills. Principal component analyses showed that the Northeastern Patagonia regiolect also differed significantly from the other two regiolects in the theme. In turn, the Espinal and Southeastern Patagonia regiolects differed in various trill variables. Notably, these patterns of vocal variation were decoupled from the gradual transition between the typical black-striped crowns and the gray crowns characteristic of Z. c. australis. Possible non-exclusive factors underlying this vocal variation, particularly the trill-less songs in northeastern Patagonia, include stochastic processes, song-learning biases, adaptation to environmental acoustics, and, most likely, differences in migratory patterns.

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References

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Agustin I. Casale, Victoria Blanco, Pablo D. Lavinia, Darío A. Lijtmaer, Pablo L. Tubaro (2026). Revealing a complex pattern of song variation in Zonotrichia capensis australis in eastern Patagonia. El Hornero, Vol. 41 No. 2 (2026). https://doi.org/10.56178/eh.v41i2.1544

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[1] Baker AJ, Jenkins PF (1987) Founder effect and cultural evolution of songs in an isolated population of chaffinches, Fringilla coelebs, in the Chatham Islands. Animal Behaviour 35(6):1793-1803. https://doi.org/10.1016/S0003-3472(87)80072-6

[2] Baker MC (1975) Song dialects and genetic differences in white-crowned sparrows (Zonotrichia leucophrys). Evolution 29(2):226-241. https://doi.org/10.2307/2407210

[3] Baptista LF (1977) Geographic variation in song and dialects of the Puget Sound White-crowned Sparrow. Condor 79(3):356-370. https://doi.org/10.2307/1368014

[4] Barker NK (2008) Bird song structure and transmission in the Neotropics: trends, methods and future directions. Ornitología Neotropical 19(2):175-199. [URL: https://digitalcommons.usf.edu/ornitologia_neotropical/vol19/iss2/2]

[5] Blumstein DT, Turner AC (2005) Can the acoustic adaptation hypothesis predict the structure of Australian birdsong? Acta Ethologica 8(1):35-44. https://doi.org/10.1007/s10211-005-0107-7

[6] Boncoraglio G, Saino N (2007) Habitat structure and the evolution of bird song: a meta-analysis of the evidence for the acoustic adaptation hypothesis. Functional Ecology 21(1):134-142. https://doi.org/10.1111/j.1365-2435.2006.01207.x

[7] Brown TJ, Handford P (1996) Acoustic signal amplitude patterns: A computer simulation investigation of the acoustic adaptation hypothesis. Condor 98(3):608-623. https://doi.org/10.2307/1369573

[8] Brown TJ, Handford P (2000) Sound design for vocalizations: Quality in the woods, consistency in the fields. Condor 102(1):81-92. https://doi.org/10.1093/condor/102.1.81

[9] Campagna L, Kopuchian C, Tubaro PL, Lougheed SC (2014) Secondary contact followed by gene flow between divergent mitochondrial lineages of a widespread Neotropical songbird (Zonotrichia capensis). Biological Journal of the Linnean Society 111(4):863-868. https://doi.org/10.1111/bij.12272

[10] Cardoso GC (2013) Using frequency ratios to study vocal communication. Animal Behaviour 85(6):1529-1532. https://doi.org/10.1016/j.anbehav.2013.03.044

[11] Chapman FM (1940) Post-glacial history of Zonotrichia capensis. Bulletin of the American Museum of Natural History 77:381-438

[12] Danner JE, Fleischer RC, Danner RM, Moore IT (2017) Genetic population structure in an equatorial sparrow: roles for culture and geography. Journal of Evolutionary Biology 30(6):1078-1093. https://doi.org/10.1111/jeb.13065

[13] Dooling RJ, Blumenrath SH (2013) Avian sound perception in noise. In: Brumm H (eds) Animal communication and noise. Animal Signals and Communication, vol 2. Springer, Berlin, Heidelberg. Pp. 229-250. https://doi.org/10.1007/978-3-642-41494-7_8

[14] Ey E, Fischer J (2009) The ‘acoustic adaptation hypothesis’—a review of the evidence from birds, anurans and mammals. Bioacoustics 19(1-2):21-48. https://doi.org/10.1080/09524622.2009.9753613

[15] Fracas PA, Rojas Ripari JM, Mahler B, Dominguez M (2023) Yellow Cardinal (Gubernatrix cristata) males respond more strongly to local than to foreign dialects. Ibis 165(4):1318-1330. https://doi.org/10.1111/ibi.13206

[16] Francis CD, Phillips JN, Barber JR (2023) Background acoustics in terrestrial ecology. Annual Review of Ecology, Evolution, and Systematics 54(1):351-373. https://doi.org/10.1146/annurev-ecolsys-102220-030316

[17] García NC, Arrieta RS, Kopuchian C, Tubaro PL (2015) Stability and change through time in the dialects of a neotropical songbird, the Rufous‑collared Sparrow. Emu – Austral Ornithology 115(4):309-316. https://doi.org/10.1071/MU14099

[18] Handford P (1981) Vegetational correlates of variation in the song of Zonotrichia capensis. Behavioral Ecology and Sociobiology 8(3):203-206. https://doi.org/10.1007/BF00299831

[19] Handford P (1985) Morphological relationships among subspecies of the rufous-collared sparrow, Zonotrichia capensis. Canadian Journal of Zoology 63(10):2383-2388. https://doi.org/10.1139/z85-352

[20] Handford P (1988) Trill rate dialects in the rufous‑collared sparrow, Zonotrichia capensis, in northwestern Argentina. Canadian Journal of Zoology 66(12):2658-2670. https://doi.org/10.1139/z88-391

[21] Handford P (2005) Latin accents: Song dialects of a South American sparrow. Birding 37:510-519

[22] Handford P, Nottebohm F (1976) Allozymic and morphological variation in population samples of rufous-collared sparrow, Zonotrichia capensis, in relation to vocal dialects. Evolution 30(4):802-817. https://doi.org/10.2307/2407819

[23] Handford P, Lougheed SC (1991) Variation in duration and frequency characters in the song of the rufous-collared sparrow, Zonotrichia capensis, with respect to habitat, trill dialects and body size. Condor 93(3):644-658. https://doi.org/10.2307/1368196

[24] Hardt B, Benedict L (2021) Can you hear me now? A review of signal transmission and experimental evidence for the acoustic adaptation hypothesis. Bioacoustics 30(6):716-742. https://doi.org/10.1080/09524622.2020.1858448

[25] Heinemann D (1981) Song dialects, migration, and population structure of Puget Sound White-crowned Sparrows. The Auk 98(3):512-521. https://doi.org/10.1093/auk/98.3.512

[26] Hudson EJ, Creanza N (2022) Modeling how population size drives the evolution of birdsong, a functional cultural trait. Evolution 76(6):1139-1152. https://doi.org/10.1111/evo.14489

[27] Hudson WH (1920) In Birds of La Plata. Vol. 1. J.M. Dent & Sons, E.P. Dutton & Co, London & New York. Pp. 480

[28] King JR (1972) Variation in the song of the rufous‑collared sparrow, Zonotrichia capensis, in northwestern Argentina. Zeitschrift für Tierpsychologie 30(4):344-373. https://doi.org/10.1111/j.1439-0310.1972.tb00863.x

[29] King JR (1974) Notes on geographical variation and the annual cycle in Patagonian populations of the Rufous‑collared Sparrow Zonotrichia capensis. Ibis 116(1):74-83. https://doi.org/10.1111/j.1474-919X.1974.tb00224.x

[30] Kopuchian C, Lijtmaer DA, Tubaro PL, Handford P (2004) Temporal stability and change in a microgeographical pattern of song variation in the Rufous‑collared Sparrow. Animal Behaviour 68(3):551-559. https://doi.org/10.1016/j.anbehav.2003.10.025

[31] Lavinia PD, Campagna L, Carboni M, Barreira AS, Lougheed SC, Tubaro PL, Lijtmaer DA (2025) Selection on a single locus drives plumage differentiation in the Rufous-collared Sparrow (Zonotrichia capensis). Evolution 79(7):1310-1321. https://doi.org/10.1093/evolut/qpaf077

[32] Lijtmaer DA, Tubaro PL (2007) A reversed pattern of association between song dialects and habitat in the Rufous‑collared Sparrow. Condor 109(3):658-667. https://doi.org/10.1093/condor/109.3.658

[33] Lisovski S, Wingfield J, Ramenofsky M, Barroso O, de Aguilar JR, Valeris-Chacín CE, Jara R, Aguirre F, Quilodrán CS, Rozzi R, Sandvig E, Vásquez RA (2025) Migration in Rufous-Collared Sparrows (Zonotrichia capensis) from the Southernmost Tip of America. Austral Ecology 50(3):e70041. https://doi.org/10.1111/aec.70041

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