The Condor 101:439-446 © The Cooper Ornithological Society 1999 MOLECULAR SYSTEMATICS OF THE RHINOCRYPTID GENUS PTEROPTOCHOS' R. TERRY CHESSER^ Department of Ornithology, American Museum of Natural History, New York, NY ¡0024 Abstract. Relationships within the rhinocryptid ge- sidered a distinctive species since its original descrip- nus Pteroptochos (huet-huets and turca) were investi- tion by Kittlitz (1830), whereas the Black-throated gated using complete sequences of the mitochondrial Huct-Huet, P. tarnii, of southern Chile and adjacent genes COII and ND3. Phylogenetic analysis of multi- Argentina, and the Chestnut-throated Huet-Huet, P. ple individuals per taxon revealed that P. castaneus, castaneus, of central Chile, have been alternately rec- P. tarnii, and P. megapodius constitute separate line- ognized as distinct biological species (Hellmayr 1932, ages, with P. castaneus and P. tarnii as sister taxa, and Goodall et al. 1946, Ridgely and Tudor 1994) or as P. megapodius sister to these. Bootstrap support for the subspecies P. t. tarnii and P. t. castaneus, respec- these results was strong (79-100%). Sequence diver- tively (Johnson 1967, Fjeldsâ and Krabbe 1990, Sibley gence between species was high, ranging from 6.1% and Monroe 1990). Contributing to this taxonomic un- between P. castaneus and P. tarnii to 7.6% between certainty is the allopatric distrijjution of P. tarnii and P. castaneus and P. megapodius. High genetic diver- P. castaneus. Ranges of these taxa, both of which in- gence between P. castaneus and P. tarnii is consistent habit the understory of Nothofagus forest, have gen- with plumage and vocal differences between these erally been considered to be delimited by the Bio-Bio taxa, and they appear to be separate species under both River in south-central Chile, with P. castaneus to the biological and phylogenetic species concepts. The Bio- north and P. tarnii to the south (Goodall et al. 1946, Bio River, a proposed dispersal barrier to P. tarnii, Ridgely and Tudor 1994, HowcU and Webb 1995). may be ineffective in limiting gene flow in this species, Rivers have long been recognized as important bar- east of its confluence with the Laja River. riers to dispersal and gene flow, and thus as potentially Key words: Chile, huet-huet, Nothofagus forest, important causes of allopatric speciation (Mayr 1963). phylogenetics, riverine barriers, species limits, turca. Riverine barriers are especially important in Amazon- Resumen. Las relaciones filogenéticas dentro del ia, where the Amazon and its major tributaries prom- género rhinocrypto Pteroptochos (huet-huets y turca) inently separate the ranges of many species of birds fueron investigadas usando secuencias completas de and primates (Wallace 1852, Sick 1967, Hershkovitz los genes mitocondriales COII y ND3. Los análisis fil- 1977), and also restrict intraspecific gene flow (Cap- ogenéticos que incluyeron múltiples individuos por parella 1988, Peres et al. 1996). This phenomenon is taxón revelaron que P. castaneus, P. tarnii, y P. me- geographically widespread, however, and Chilean riv- gapodius constituyen taxones separados. Pteroptochos ers, such as the Maipo and the Yeso, have also been castaneus y P. tarnii son taxones hermanos, y P. me- shown to limit dispersal and gene flow (Lamborot and gapodius es el taxón hermano a estos. El apoyo de Eaton 1992). Riverine barriers should be most effec- "bootstrap" de estos resultados fue fuerte (79-100%). tive in their wide lower reaches, and their effectiveness La divergencia entre las secuencias fue alta, de 6.1% is expected to diminish in their relatively narrow upper entre P. castaneus y P. tarnii y de 7.6% entre P. cas- reaches and headwaters (Hershkovitz 1977). For in- taneus y P. megapodius. Esta considerable divergencia stance, the upper half of the Bio-Bio River is much genética entre P. castaneus y P. tarnii concuerda con narrower than its lower reaches (Vuilleumier 1985), las diferencias que hay entre estas especies en plumaje and Behn's (1944) original description of range delim- y vocalizaciones. Por estos resultados se recomienda itation in Pteroptochos restricted the distributional bar- que estos dos taxa sean considerados especies separa- rier to the relatively wide portion of the river below das en términos biológicos y filogenéticos. Es posible its confluence with the Laja Riven The suggestion that que el río Bío-Bío, propuesto como una barrera a la the upper Bio-Bio may not be an effective geograph- dispersión de P. tarnii, no sea efectivo al este de su ical barrier (Vuilleumier 1985) is supported by the re- confluencia con el río Laja en limitar el flujo genético cent collection of the first specimen of P. tarnii from de estas especies. north of the Bio-Bio (Chcsser, unpubl. data). In this paper I report the results of a molecular sys- Pteroptochos is a genus of large, mainly terrestrial ta- tematic investigation of the genus Pteroptochos with paculos (Passeriformes: Rhinocryptidae), generally reference to the following questions: (1) What are the considered to consist of two or three species. The phylogenetic relationships among Pteroptochos spe- Moustached Turca, P. megapodius, is endemic to arid cies? Are tarnii and castaneus sister taxa, as has been areas of central and northern Chile, and has been con- traditionally assumed? (2) How divergent genetically are the species of Pteroptochos"! Do tarnii and casta- neus show genetic differentiation typical of avian sister ' Received 16 June 1998. Accepted 14 January 1999. species? (3) Does the Bio-Bio River appear to be an ^ Current address: Department of Ecology and Evo- effective barrier to gene flow? Is a tarnii individual lutionary Biology, University of Arizona, Tucson, AZ obtained from the north side of the Bio-Bio River ge- 85721, e-mail: [email protected] netically similar to individuals from south of this river? [439] 440 SHORT COMMUNICATIONS 73°W 72°W 71° N 1 1 1 J3e P. castaneus . o bO U 470, 471 , J \ ( ^ -o O "3 S " 1 • 37°S Z g oí J Rio Laja o / ^ 0) w tu Ë W >\ -o H c/3 tarnii 450 Xi 1^ -a rubecola 452 s on ^ o Bío-Bío~^ o >- XI ^ C/1 e ^ P. tarnii 45 5\ > s 13 s s j£ S E U ci x> . o . \ ci o rt •p. tarnii 462 o ^O o U ta "^ •39°S N2 a' >2' (5 Mffl ¡ ffl M 2 "O X o U >Z eQ ^ m m^ SE CHILE y m 'y O ., ^ 40°S l B o o X) o CX^ OH S Oi " c o =1 ARG. Agi -W ca'-o 0) Ä o s v2 ^o -a p es PQ sz ca (£I s (SI l/-\o • •S cá ca o o -41 "S o U v2 w .2 - ••* ^t ryÎ ^ ^ D- - T-H" PQ 03=^03,2 O u la l \ faS > - h-H u o • P3 H 3 g C H t S. rubecola PRS 1125 > .> a X! s s^ > 'o > c c a3 c o c c s a I § W o C o o ce o j^ o o eo 0- C FIGURE 1. Map showing localities for individual •&"• •¡•u bo c 'S ¿j '50'* '^ '^ 6 -^ a Pteroptoclios tarnii, P. castaneus, and Scelorcfiilus ru- Oí o I oí o oí m oí ° oí oí pa .s (5 becola sequenced for this study. Both specimens of P. .. fc . o - - • - - 11 CD CN i; ;; oc.. megapodius were collected north of the area depicted. ^u^2^-r=o:9^ o: ^ 9 ^ 0Í 60 g U U U U UU <ÎOH METHODS s ^ Two P. megapodius, two P. castaneus, and three P. tarnii were sampled (Table 1, Fig. 1), as well as two ^ ô t^ îj- ïj- r- V o m (N m ji o m Chucao Tapaculo, Scelorciiiius rubecola (one of two b m ^ ^-" C/Í t~ <~ r- t- r^ 1^ r- r-- species of the presumed sister genus to Pteroptociios), c/5 00 M t/i CO 00 M" C/ÎP and one Magellanic Tapaculo, Scytaiopus mageiiani- cus, a relatively distant outgroup within the family p ^ Rhinocryptidae (Sibley and Ahlquist 1990). Tissue •< ci samples of the Pteroptoclios species and Scelorchilus rubecola were obtained during fieldwork in Chile and Argentina (RTC and PRS reference numbers, for col- lectors R. T. Chesser and P. R. Sweet, in Table 1; vouchers at the American Museum of Natural History, New York, New York). A sample of Scytaiopus ma- ü öo gellanicus was obtained from the Genetic Resources U 03 Collection of the Louisiana State University Museum of Natural Science, Baton Rouge, Louisiana. in •T3 o u DNA was extracted using a 5% Chelex solution CI H U ?î 8 (Walsh et al. 1991). Two complete protein-coding mi- O ;^ »0 Oí osÍ- tochondrial genes, cytochrome oxidase II (COII, 684 ^ u U J •n s base pairs) and NADH dehydrogenase subunit 3 (ND3, G • S M Oí S ^3 -a ^ 351 base pairs), were amplified using the polymerase ni î! chain reaction (PCR). Typical PCR conditions were an J h initial denaturation at 94°C for 4 min, followed by 41 m ïU -Cl cycles of denaturation at 94°C for 1 min, annealing at < •• cj . u H s 0, Co CO Co 50°C for 45 sec, and extension at 72°C for 1 min 20 SHORT COMMUNICATIONS 441 sec. These reactions were conducted in a Peltier-effect pairs, due to only one primer pair amplifying a nuclear thcrmocycler (MJ Research), using 50 ^L1 reaction vol- copy, (4) slower evolution than in mtDNA, yielding umes, including 5 |ji,l of 2 niM dNTPs, 5 (xl of lOX shorter branch lengths, and (5) evolution atypical of reaction buffer, 5 [xl of MgCK, 2.5 jj.1 of each 10 ixM functional mtDNA sequences, resulting in protein primer, 1.5 (JLI of Chelex-extracted DNA, and 0.3 |JL1 of changes, stop codons, or length variation.