The Auk 117(2):465-478, 2000 DISPLAY BEHAVIORS, MECHANICAL SOUNDS, AND EVOLUTIONARY RELATIONSHIPS OF THE CLUB-WINGED MANAKIN (MACHAEROPTERUS DELICIOSUS) KIMBERLY S. BOSTWICK • Departmentof Ecologyand EvolutionaryBiology and Natural HistoryMuseum, Universityof Kansas,Lawrence, Kansas 66045, USA ABSTRACT.--MaIeClub-winged Manakins (Machaeropterusdeliciosus) are known to pro- ducea uniquemechanical sound with their extremelymodified secondary feathers, yet the speciesremains poorly known behaviorally. I observedlekking males in ReservaMaquip- ucuna, Pichincha Province, Ecuador, to better understand the role of mechanicalsounds, the behavioralrepertoire, and otherdetails of the naturalhistory of thisspecies. The behavioral repertoireof M. deliciosusis much more diverse than previously documented; it includesfour mechanicalphrases, two vocalsounds, and seven display behaviors. Mechanical sounds con- stitutethe mostprominent elements of the species'displays, replacing vocal sounds for ter- ritorial advertisement.I examine possible homology of the observedbehaviors and propose a newphylogenetic hypothesis, that Machaeropterus forms a monophyleticclade with thege- nusPipra, based on theexistence of a complexshared courtship display. Received 20 July 1998, acceptedI October1999. THE FAMILYPIPRIDAE, the Neotropicalman- soundsproduced by structuresother than the akins, is a clade of approximately40 sexually syrinx and used for the purposeof communi- dimorphiclek-breeding species (Prum 1992). cation(Prum 1998).The productionof mechan- The bright plumagesand elaboratedisplays of ical sounds,although common in manakins,is male manakins have attracted considerable at- relatively rare in birds as a whole, and Club- tentionover the last century(e.g. Snow 1963b, winged Manakinsproduce mechanical sounds Sick 1967,Prum 1990).Surprisingly, however, that are acousticallyunique (Prum 1998).The displaysof mostspecies in the family havenot lack of detailed behavioral information has hin- beenobserved or describedin detail,and many dered our understandingof the evolutionand are known by little more than anecdotalde- physicalmechanics of this unusual mode of scriptions(Prum 1990, 1996). communication. The Club-wingedManakin (Machaeropterus Althoughconsidered the best-known species deliciosus)is endemic to humid forests of the in its genus (Prum 1990), current behavioral western slopesof the Andes in southwestern descriptionsof Club-winged Manakins are in- Colombia and northwestern Ecuador (Hell- complete. Willis (1966) and Orejuela et al. mayr 1929, Hilty and Brown 1990). Like most (1982) reported a display in which the wings other manakins,they are sexuallydimorphic. are thrown open and mechanicalsounds are Femaleshave drab olive-greenplumage, and produced.Willis (1966) noted that the wings males have a chestnut-coloredbody, a red produce the unusual mechanicalsounds, but crown,and wings that are white ventrallybut he did not observethe behaviorin any detail. black dorsallywith peculiarwhite, thickened Indeed, the rapid and brief nature of the dis- shaftson the secondaries(Orejuela et al. 1982, playsmake them extremely difficult to describe Ridgely and Tudor 1994). withoutthe aid of video.Orejuela et al. (1982) Darwin (1871) described the secondary made extensive observations of habitat and lek feathersof male Club-wingedManakins as an characteristicsand discussedthe evolutionary example of structural modificationsfor pro- importance of lek-breeding in this species. duction of "instrumental music," or mechani- cal sounds. Here, I use the term "mechanical They alsodescribed the mechanicalsound dis- play in more detail, as well as a vocalization sounds" to mean intentionally modulated and copulatorybehaviors. However, details necessaryfor understandinghow the mechan- E-mail: [email protected] ical soundsare producedwere lacking. Neither 465 466 KIMBERLYS. BOSTWICK [Auk, Vol. 117 Ilicurini placementof Machaeropterusmay have resulted Machaeropterini from a lack of informativecharacters. Many be- Manacini haviors described herein for Club-winged Manakins have not been describedpreviously Xenopipo and,therefore, may provide information on the Dixiphia relationshipsof this speciesto othermanakins. __ Heterocercus In thispaper I havetwo objectives.First, I de- scribe the display behaviorsof male Club- winged Manakins,including detailed accounts --t --subga. Pipra Piprini-- Ceratopipra of the displays,data on frequencyof useof me- chanicalsounds, and othernatural history ob- FIG. 1. Hypothesisof relationshipsamong mem- servations.Second, I proposea newhypothesis ber taxa (tribes,genera, and subgenera)of Pipridae of the phylogeneticrelationships of the Club- modified from Prum (1992).Tribe membership:Ili- winged Manakin suggestedby the newbehav- curini includes Ilicura militaris, Masius chrysopterus, ioral information and discussits implications and Corapipospp.; Machaeropteriniincludes Ma- for the evolution of mechanical sounds. chaeropterusdeliciosus, M. regulus,and M. pyrocephal- us;Manacini includesLepidothrix spp., Manacus spp., Antilophiaspp., and Chiroxiphiaspp. STUDY SITE AND METHODS Behavioraldescription.--Orejuela et al. (1982) sug- the work of Willis (1966) nor Orejuela et al. gestedthat leksof Club-wingedManakins are active (1982)attempted to describecompletely the be- for at leasteight monthsof the year, includingOc- havioralrepertoire of Club-wingedManakins. tober and November.I observed,tape-recorded, and Analyses of the evolution of mechanical video-tapedmale Club-wingedManakins for 82 h soundshave also been hampered by lack of from 28 October to 27 November 1996 at a lek on the knowledgeof the closestrelatives of the genus northeasternborder of the ReservaMaquipucuna, PichinchaProvince, northwestern Ecuador (00ø08'N, Machaeropteruswithin the Pipridae.Currently, 78ø38'W,1,500 m elevation).The lek is located1.5 km two largelycongruent hypotheses of phyloge- northwest of the T. H. Davis Ecotourist Center in a netic relationshipswithin the Pipridae have strip of secondaryforest (25 x 120 m) in a small ra- been publishedbased on behavioraland mor- vine on a steephillside. Except for a small (ca. 100 x phologicaldata sets (Prum 1990, 1992).The 100 m) patch of primary forest,the ravine is sepa- congruencebetween the behavioraland mor- ratedfrom otherforest by a grassypasture with scat- phologicalphylogenies demonstrates the infor- tered trees. mative nature of behavioral characters in man- Averagedaily minimum and maximum tempera- akins (Prum 1990). The phylogeneticposition tures were 15øCand 24øC,respectively, and relative of the genusMachaeropterus within the Pipridae humidity rangedfrom 72 to 96% (œ= 92.1%).Local was unresolvedin both phylogenies(Prum people regardedthe study period as the beginning of the rainy season,but the region receivedunsea- 1990 and 1992; summarized and condensed in sonablylow precipitation(no rain in 19 of 29 days) Fig. 1 to show the polychotomousand basal during the period of my study. placementof Machaeropterus).Although Prum's I observedunmarked individuals using8 x 40 bin- 1990behavioral data set is quitecomprehensive oculars.I made one all-day watch (0600to 1630)to (28 species,44 characters),the displaycharac- documentthe temporal pattern of activity. Thereaf- terization of the Club-winged Manakin was ter, I conducted observations between 0600 and 1130 basedonly on the observationsof Willis (1966) EST (althoughdisplay activity alwaysdeclined sub- and Orejuelaet al. (1982)and thuswas incom- stantially by 0900). No blind was used, and all notes plete.Even lesswas known of the congeners were taken by hand. Audio recordingswere made (M. regulusand M. pyrocephalus),which were with a SonyTCM 5000 recorderand SennheiserME 80 microphone.Video recordingswere made with a excludedfrom the behavioralanalysis (Prum Canon L2 8-mm camcorderusing a 15x lens and a 1990).Similarly, the only structureused in the 2 x teleconverter.Shutter speeds of 1/60 to 1/1000 s morphologicalanalysis, the syrinx,is extreme- were used as permitted by lighting conditionsto ly reduced in all members of Machaeropterus,capture the motions of the displayingbirds as clearly probablyas a resultof theirextreme reliance on as possible. Individual identities and territorial mechanical sounds for acoustic communication boundarieswere inferred from behaviorwhen pos- (Prum 1992). Thus, the unresolved and basal sible. April 2000] Club-wingedManakin Displays 467 ! measured several characteristics of the most fre- of thesespecies to assesshornology with the newly quentlyused mechanicalsound display (the wing- createdrecoded characters. The 11 specieswere Mas- flash display),which is usually composedacousti- ius chrysopterus(Prum and Johnson1987), Manacus cally of two ticksfollowed by oneting. Frequencies of manacus(Snow 1962a), Lepidothrixcoronata (Skutch tickspreceding tings were counted from 200 video- 1969), Dixiphia pipra (Snow 1961), Pipra fasciicauda taped wing-flash displays. For two males, I mea- (Robbins 1983), P. filicauda (Schwartz and Snow sured the following parametersfrom SOhogramsof 1978), P.aureola (Snow 1963a), P.cornuta (Snow 1977), 20 wing-flash displays produced using CANARY P. mentalis(Skutch 1949, 1969), P. rubrocapilla(Sick 1.2.1 (Charif et al. 1995): (1) the time interval be- 1967), and P.erythrocephala (Lill 1976,Snow 1962b). tween the onsetsof the first and secondticks, (2) the ! used the new behavioraldata from Club-winged time between the onset of the second tick and the ini- Manakins in three combinations to form three dif-