Ornis Fennica 83:153–161. 2006

Heterospecific rival recognition in the Black Redstart (Phoenicurus ochruros)

Ondøej Sedláèek*, Blanka Cikánová & Roman Fuchs

Sedláèek, O., Charles University, Faculty of Science, Department of Ecology, Vinièná 7, CZ-128 44 Praha 2, Czech Republic. [email protected] (* Corresponding author) Cikánová, B., University of South Bohemia, Faculty of Biological Sciences, Branišovská 34, CZ-370 05 Èeské Budìjovice, Czech Republic. [email protected] Fuchs, R., University of South Bohemia, Faculty of Biological Sciences, Branišovská 34, CZ-370 05 Èeské Budìjovice, Czech Republic. [email protected]

Submitted 23 September 2005, revised 3 May 2006, accepted 25 May 2006

It has long been hypothesized that birds learn to recognize heterospecific competitors and for that reason males behave more aggressivelyagainst intruders in areas of local sym- patry. Recently, it has been confirmed that individuals of one species are able to learn spe- cies-specific visual and acoustic characteristics of heterospecific rivals and that theyare able to remember these associations. Here, we test hypotheses about the importance of learning in interspecific interactions, long-term memoryof species-specific traits and earlytiming of this learning to the post-fledging period in the Black Redstart (Phoenicurus ochruros). We show that Black Redstart males respond to playbacks of Redstart (P. phoenicurus) onlyin the areas where the two s pecies come into close contact. This result demonstrates that Black Redstart males learn individuallyto recognize the ri - val species in areas of local coexistence. Black Redstart males responded in heterospeci- fic experiments before the arrival of Redstarts from wintering grounds. This means that birds are able to retain the memoryof specific traits of heterospecific competitors to the next breeding season. Moreover, yearling and older males, which differ in plumage colouration, responded in heterospecific experiments with the same frequencyand inten - sity. This result indicates that young males learn to recognize Redstarts in the post-fledg- ing period before a first contact with heterospecific rivals in a territorial context.

1. Introduction that some interactions mayresult from misdirected intraspecific aggression, which is a consequence Birds often defend resources against individuals of of a failure to discriminate a different species with another species with similar ecologyliving in local similar appearance and/or song. sympatry(Cody1969). The original view of inter - Catchpole (1978) predicted that if a general specific aggression (Simmons 1951, Orians & failure to recognize different species is responsible Wilson 1964, Cody1969) supposes that it is an for interspecific aggression (Murray1981), indi - adaptive behaviour, which reduces interspecific viduals should show the same response to hearing competition between sympatric species. On the a playback of another species in a population other hand, Murray(1971, 1976, 1981) suggests where this other species also occurs (sympatric po- 154 ORNIS FENNICA Vol. 83, 2006 pulation) as in a population where this other spe- birds are able to learn species-specific signal traits cies does not occur (allopatric population). Many (song, plumage, behaviour etc.) (Gill & Murray experimental playback studies addressed this 1972, Irwin & Price 1999), there was no direct question about the origin and ecological relevance evaluation of whether individuals of one species of interspecific aggression. Lower levels of ag- are able to learn species-specific characteristics of gression in sympatry were found for Dendroica heterospecific intruders and if theyare able to re - warblers (Murray& Gill 1976), Vermivora war- member these associations. blers (Crook 1984), Acrocephalus warblers (Leis- Matyjasiak (2005) tested in his dual-choice ex- ler 1988) and Fringilla finches (Slater & Catch- periments the heterospecific recognition ability pole 1990, Lynch & Baker 1991). Although the and long-term memoryof Blackcaps (Sylvia atri- occurrence of stronger heterospecific response in capilla) that behave aggressivelytowards Garden allopatric populations implies misidentification Warblers (S. borin). He showed that male Black- (Murray1981), this result could be interpreted al - caps can associate species-specific songs with spe- ternativelyas an adap tive abilityto distinguish cies-specific plumage type. As he carried out the species which poses no ecological threat (Slater & playback experiments on Blackcap males before Catchpole 1990). the arrival of Garden Warblers, he showed that Stronger interspecific aggression in sympatry birds retain the memoryof these associations from was seen in Passerina buntings (Emlen et al. year to year. He also asked when Blackcap males 1975), Empidonax flycatchers (Prescott 1987), learn to recognize heterospecific intruders and as- Luscinia warblers (Lille 1988, Sorjonen 1986) and sumed that this abilitydevelops before the first Certhia treecreepers (Gil 1997). This aggressive breeding attempt in young Blackcaps. However, behaviour has been interpreted as being adaptive he was unable to estimate the age of tested males in these cases as it results in interspecific terri- and he documents his result onlyindirectlyusing a toriality, which prevents exploitation competition. proportion of particular age categories of males Martin and Martin (2001a, b) confirmed that be- living in the studyarea. havioural responses of Vermivora warblers to The Black Redstart (Phoenicurus ochruros) heterospecifics reflect ecological interactions of and Redstart (P. phoenicurus) provide a unique the species. opportunityto test hypotheses about the origin of Catchpole (1978) and Catchpole and Leisler interspecific aggression, learning of heterospe- (1986), who studied the interspecific aggression of cific recognition and long-term memoryof this Acrocephalus warblers, confirmed stronger hete- learned identification ability. rospecific response in the area of coexistence with New molecular data support the view that the the opposite warbler species. As in previous cases, Black Redstart and the Redstart are not very theysuggest that this behaviour serves as the terri - closelyrelated (Ertan 2002). There are major dif - torial exclusion of competing species. Moreover, ferences in the song structure (for spectrograms theyfirst pointed out that birds individuallylearn see e.g. Cramp 1988) and male colouration be- to recognize and respond to the songs of conge- tween them. Both species have a slate-greyhead neric competitors onlyin areas of the species’ and upperparts, orange-chestnut tail and rump. close contact. However, the Redstart male has black sides of the A number of recent studies have shown the im- face and throat, white forehead and orange-chest- portance of learning as a source of heterospecific nut flanks, whereas the Black Redstart has black recognition abilityin other contexts such as brood flanks and white wing-patches. parasitism (Payne et al. 2000, Slagsvold & Hansen The two species inhabit different types of habi- 2001), sexual rival and mate recognition (Hansen tats under natural conditions. Black Redstarts pri- & Slagsvold 2003, Slagsvold et al. 2002), the es- marilybreed in open rockyterrain while Redstarts tablishment of mating preferences during speci- favour open woods (Cramp 1988). Both redstart ation and premating reproductive isolation of species can associate with human beings and they sympatric species (Grant & Grant 1996, 1998, maycome into close contact in a mosaic urban en - Price 1998, Irwin et al. 2001). vironment. In such a situation, theyoccupyexclu - Although it has long been hypothesized that sive territories of different habitat compositions. Sedláèek et al.: Heterospecific rival recognition in Black Redstart 155

Each of the two species occupies habitat similar to 2. Material and methods that preferred under natural conditions (Sedláèek et al. 2004). Nevertheless, spontaneous interspeci- 2.1. Study sites fic conflicts were frequentlyobserved in areas where territories adjoin and the interspecific ag- Experiments were conducted in two towns (50 km gression was reliablyconfirmed in playbackex - apart) located in the south of the Czech Republic – periments. The Black Redstart is dominant in both Bøeznice (3500 inhabitants; 13E56’E, 49E34’N) natural and simulated encounters (Sedláèek et al. and Èeské Budìjovice (100,000 inhabitants; 2004). Both redstart species are migratory. Red- 14E29’E, 49E00’N). starts migrate to sub-Saharan Africa, whereas The studyarea in Bøeznice is veryheteroge - Black Redstarts winter in the Mediterranean area neous, consisting of a mosaic of diverse urban (Cramp 1988). Black Redstarts arrive at breeding habitats – industrial sites, several types of built-up areas about 3 weeks before Redstarts and leave areas (urban villas, terraced houses and apartment about 1 month later. Thus the two species cannot houses), sports fields, gardens, tree alleys, three interact with each other during migration and in small and one larger park. Populations of both spe- their winter quarters. cies are mixed and heterospecific individuals may In Black Redstarts, males exhibit delayed frequentlybe immediate neighbours, thanks to the plumage maturation during their first breeding mosaic nature of diverse urban habitats. We label season. The young males entering their second this site as ‘sympatric’. year of life are female-like dull grey, whereas In the larger town, Èeské Budìjovice, the two older males are black with a white wing-patch redstart species are present, but theyare spatially (Cramp 1988). well separated due to the much coarser mosaic of In this study, we investigated the response of urban habitats. Black Redstart males were tested the Black Redstart to playback of Redstart songs in within two large housing estates where onlythis a larger citywhere Black Redstarts occur sepa- species is present. These housing estates consist of rately(Èeské Budìjovice) and in a small town large blocks of flats alternating with open, grassy (Bøeznice) where the two species come into close areas with interspersed trees and shrubs. We label contact. The objective was to address three ques- this site as ‘allopatric’. tions: (1) Is the interspecific aggression of Black Redstarts stronger in the area where territories of the two species are mixed and heterospecific indi- 2.2. Mapping of redstart territories viduals are immediate neighbours? (2) Do Black Redstart males respond in heterospecific experi- In 1999, we investigated the number of territories ments before the arrival of Redstart males from of both redstart species in Bøeznice and Èeské their wintering grounds? (3) Do yearling males re- Budìjovice. We carried out three surveys during spond to heterospecific playback before the arrival the breeding season – at the end of April, middle of of Redstarts? Mayand middle of June. If a male was seen in the Stronger responses in sympatry would imply samegeneralareainatleasttwoofthreecensuses that Black Redstarts learn heterospecific recogni- a territorywas recorded at the location. The map - tion and aggressive response to Redstarts. Positive ping covered the whole area of Bøeznice (about answers to the other questions would demonstrate 200 ha) and the northern part of Èeské Budìjovice that Black Redstarts remember once-learned he- (about 770 ha), representing all urban habitats in- terospecific intruders from year to year and that cluding the largest park. young Black Redstart males learn to recognize a heterospecific competitor in the year of their birth, before theyuse this abilityin a territorial context. 2.3. Experiments

We carried out the playback experiments between the 1st and 20th of April in the years 2002 and 2003, before the arrival of Redstarts from spring migra- 156 ORNIS FENNICA Vol. 83, 2006 tion. The experiments consisted of song playback ments belonged to the same Redstart song dialect with a fixed artificial stuffed dummy. We used two at onlyone of the studied localities, which are only differentlycoloured dummies for conspecific 50 km apart, and that this might stronglyinfluence playback because of the occurrence of delayed- the responses of Black Redstart males in hetero- plumage-maturation in the Black Redstart (Land- specific experiments. mann & Kollinsky1995) and the possible weaker The sample was 25 males (15 in 2002 and 10 in response of 1-year-old males (in their second cal- 2003; 11 1-year-old and 14 older males) in the endar year of life) to older males (Cucco & Mala- sympatric and 33 (20 in 2002 and 13 in 2003; 12 1- carne 1999). Males were presented with dummies year-old and 21 older males) in the allopatric area. of an age class identical to their own age class We located territoryboundaries before experi - (graydummypresented to 1-year-oldmales, black ments and we placed the sound-producing dummy dummyto older males). For auditoryplaybackwe at distances of 2–40 m from a singing or foraging used a CD-player (Sony D-EJ611) with two loud- male inside the territoryat a site where each male speakers (Panasonic RP-SP70). We used the same could definitelysee the dummy.The experiment equipment at both localities, the amplitude was duration was 10 min. This time was measured standardized and it was similar to that of natural from the first response (approach, threat displayor singing. Loudspeakers were placed 1.5–15.0m pass attack) of the male. If we did not record any above the ground. We did not perform control response (no approach to the dummy, no threat tests, because we did not record anyaggressive re - displays, or the male flew away), the experiment sponses to control playback (Robin Erithacus was finished after 10 min from the start of song rubecula) in our previous study(Sedláèek et al. playback. Behaviour and position of a focal male 2004) and pilot experiments. was continuouslytape-recorded during the whole Playback tapes were prepared from recordings trial period. of Pelz (1993). These recordings consist of a typi- Each male was tested first with conspecific and cal song of one male of each species. The Black second with heterospecific playback. We used this Redstart recording was 73 s long with 6 songs; the sequence to be sure of accurate location of the ex- Redstart recording was 58 s long with 8 songs. perimental apparatus inside a territoryand that These recordings were repeated continuallydur- Black Redstart males were prepared to respond to ing experiments. Although the use of a single song playback, at least to the conspecific song. As all sample for each playback treatment could be con- birds tested gave some initial response in con- sidered as pseudoreplication (Kroodsma et al. specific experiments, all of them are included in 2001), there are reasons to justifyit. We suppose the analysis. The two trials in a given territory were that the problem of intraspecific song variation is separated byat least 2 hours and the speaker was not that severe in our case. Firstly, songs from two placed in an identical location. different species with verydistinct songs are used. The observed response of the bird was re- It is likelythat the specific traits outweigh local or corded continuouslyduring the experiment and individual differences in the song structure that dictated into a dictaphone. We recorded locality, might affect the response. Secondly, we did not playback presented to a male, date and time of the find anydifferences in intraspecific responses be - trial and age of the experimental bird. The follow- tween the two localities suggesting that males at ing variables were measured: 1. latencyof re - both localities recognized species-specific play- sponse, 2. nearest distance to the loudspeaker, 3. back. Thirdly, we cannot definitely exclude an in- time spent within a 15 m circular plot around the fluence of dialectal differences of Redstart songs loudspeaker, 4. time spent singing during the ex- between the two studied localities in heterospeci- periment, 5. number of pass flights over the fic experiments. However, the recording of dummy(flying back and forth over the dummy Redstart comes from Prušánkyvillage (16 E59’E, within 10 m), 6. time spent in threat display(ruf - 48E50’N), South Moravia, Czech Republic. This fled feathers, frequent tail-shivering and squatting, localityis ca 220 km from È. Budìjovice and 260 shaking) (Landmann & Kollinsky, 1995) and 7. km from Bøeznice. It is highlyimprobable that the number of physical attacks (”kicking” the dummy, song recording of Redstart used in our experi- pecking). Sedláèek et al.: Heterospecific rival recognition in Black Redstart 157

Conspecific 2.4. Statistical analyses 100 sympatry; n = 25 allopatry; n = 33 We compared the proportions of males that re- 80 sponded by approach, threat displays, pass flying and physical contacts using Fisher Exact Tests; P- 60 % values were adjusted for multiple testing 40 (Bonferroni adjustment). Significant levels refer to a = 0.0125 in these tests. 20 Principal Component Analysis (PCA) was 0 performed for visualizing the differences and the approach aggressive display pass attack physical contact Heterospecific variabilityin response of Black Redstart males in 100 sympatry; n = 25 conspecific and heterospecific trials at the two lo- ** allopatry; n = 33 ** calities. PCA was computed using CANOCO 4.5 80 ** and visualized in CANODRAW 4.0 (ter Braak & ** Šmilauer 2002). PCA is a noncanonical multi- 60 % variate statistical technique that enables one to re- 40 duce the dimensionalityof the original set data by * extracting a few complex orthogonal variables, 20 and it describes variation with a minimal loss of in- 0 approach aggressive display pass attack physical contact formation (ter Braak & Šmilauer 2002). strength of aggression

Fig. 1. Responses of Black Redstart to conspecific 3. Results and heterospecific playback and dummies in popula- tions allopatric and sympatric with Redstart. Histo- grams show proportions of males responding by ap- 3.1. Population size of the two Redstart proach within 15 m, aggressive display, pass-flight at- species in Bøeznice and Èeské Budìjovice tack or physical attack. Fisher’s Exact Tests; a = 0.0125 after Bonferroni adjustment for multiple test- In Bøeznice, we located 74 territories of Black ing:*p=0.0298,NS;**p<0.001. Redstarts (density43.9/km 2) and 26 territories of Redstarts (density15.4/km 2). Within the study area of Èeské Budìjovice, we mapped 323 Black Black Redstarts responded more stronglyto a Redstart territories (density41.8/km 2) and 30 heterospecific dummy in ‘sympatry’ (Fig. 1). The Redstart territories (density3.9/km 2). The Black proportion of responding birds was significantly Redstart is commoner in both towns, but the pro- higher for three measures of aggressive behaviour portion is much higher in È. Budìjovice. More- (Fisher’s Exact Tests; a = 0.0125 after Bonferroni over, the two species are more spatiallyseparated adjustment; n = 33, n = 25; p < 0.001.). The pro- 1 2 in this locality. In 2002, 57 Black Redstarts and portion of males responding byphysical attack onlyone Redstart occurred in the area of housing was slightly higher in ‘sympatry’, but the differ- estates where the playback experiments were con- ence was not significant (a = 0.0125 after ducted. Bonferroni adjustment; p = 0.0298). In ‘allopatry’, the proportion of males re- sponding to the heterospecific playback was sig- 3.2. Playback experiments nificantlylower than to the conspecific one (Fisher’s Exact Test; a = 0.0125 after Bonferroni The Black Redstart males responded stronglyto adjustment; n = 33; p < 0.01 for all four measures their own species’ dummy(Fig. 1). There was no of aggression). In ‘sympatry’, heterospecific reac- significant difference between ‘sympatry’ and tion was less frequent than conspecific for only ‘allopatry’ (Fisher’s Exact Test; a = 0.0125 after one measure of aggression – pass-flights (Fisher’s Bonferroni adjustment; n = 33, n = 25; p > 0.76 Exact Test; a = 0.0125 after Bonferroni adjust- 1 2 for all four measures of aggression). ment; n = 25; p = 0.008). 158 ORNIS FENNICA Vol. 83, 2006

Fig.2.Responsesof BlackRedstartmalesto conspecificandhetero- specificplaybackin allopatricandsympatric populationswithRed- startvisualizedusing thetwofirstprincipal components(PCA ordi- nation)drawnfrom7re- sponsevariables.The twoPCA axestogether explain90.1%ofvari- ability.Blacksymbols– responseinconspecific experiments;blank symbols–responsein heterospecificexperi- ments. ¡ –sympatry, o –allopatry.Larger symbolsinthelower rightcornerindicate overlapofmoresamp- lesinthebiplot.These symbolsrepresent malesthatdidnotre- spondinheterospecific experiments.

The variabilityof conspecific and hetero- aggression either in conspecific or heterospecific specific responses of the Black Redstart males at responses. both localities is visualized byPCA ordination In the ‘sympatric’ situation, we found no dif- (Fig. 2, both axes together explain 90.1% of the ferences in the proportion of responding 1-year variance). The first component accounts for and older males in either conspecific (Fisher’s Ex- 75.8% of the variance. This axis separates con- act Test; a = 0.0125 after Bonferroni adjustment; specific and heterospecific responses and the he- n = 11, n = 14; p ~ 1 for all four measures of agg- 1 2 terospecific responses in ‘sympatry’ and ‘allo- ression) or heterospecific playback experiments patry’. (Fisher’s Exact Test; AAA = 0.0125 after All variables, except time spent singing, are Bonferroni adjustment; p > 0.35 for all four mea- correlated with the first axis and explain most of sures of aggression). the response variability. The aggression of a male is characterized mostlybythe time spent within a 15 m circular plot around the loudspeaker, time 4. Discussion spent in threat display, number of pass-flights and number of physical attacks on the dummy. On the Our results show that the aggression of Black other hand, longer latencyof response and longer Redstart males to Redstarts is a local feature of the distance of an approach to the loudspeaker are ‘sympatric’ population in Bøeznice, and we sug- characteristic of less intensive aggression. The gest that this results from the coexistence of the second axis (14.3% of variance) separates males two species at this locality. The Redstart inhabits according to time theyspent singing during the ex - some parts of Èeské Budìjovice as well, but it does periments. This variable did not correlate with not occur in the vicinityof the experimental sites. Sedláèek et al.: Heterospecific rival recognition in Black Redstart 159

This points to the fact that the origin of the aggres- (1986) consider the ultimate cause of learning of sion is related to immediate contact between the heterospecifics as the prevention of interspecific two species. competition bymeans of interspecific terri - We found that the densities of the Black toriality. We suggest that the Black Redstart can Redstart and intraspecific aggression rates are readilyencounter the Red start as a competitor. De- similar at the two localities. This demonstrates that spite their different colouration, the two species the increased rate of aggression towards hetero- have verysimilar morphologyand theyuse the specifics is not a simple consequence of local dif- same foraging techniques (mainlya sit-and-wait ferences in intraspecific aggression rates. strategy) and foraging substrates (mainly on the For several reasons, results presented here can- ground) (Sedláèek et al. 2004). Moreover, both not be explained byMurrays’(1971, 1976, 1981) species breed in cavities. But the spatial distri- hypothesis. He suggests that responses to coexist- bution of redstarts differs from the other examples ing closelyrelated heterospecifics originate from of interspecific territorial birds. Contraryto the misdirected intraspecific aggression. Firstly, other pairs of congeners for whom increased inter- Catchpole and Leisler (1986), who studied the in- specific aggression has been confirmed in sym- terspecific aggression in Acrocephalus warblers, patry(Catchpole 1978, Catchpole & Leisler 1986, suggested that if a general failure to distinguish Emlen et al. 1975, Gil 1997, Prescott 1987, Sor- closelyrelated species is responsible for interspe - jonen 1986), the two redstarts are strictlyhabitat cific aggression, then sympatric and allopatric separated at the sympatric locality. Therefore, it is populations would show similar responses to the not clear if theycould be considered as inter- other species. Secondly, the “mistaken identity” specificallyterritorial and to what extent the clear hypothesis is proposed for closely related species habitat separation could be the result of interspeci- with similar appearance and song (Murray1971, fic aggression (Sedláèek et al. 2004). 1976). The principal differences in appearance The questions worth stressing are when do and song morphologybetween the two redstart Black Redstart males learn to recognize hetero- species suggest that failure to discriminate is un- specifics and if theyremember associations from likely. Thirdly, we did not record any mixed songs year to year. Matyjasiak (2005) first confirmed the (i.e. song convergence) of the two species such as long-term memoryof these associations in birds. might evoke misidentification (see Sorjonen 1986 In his experiments, Blackcap males responded to or Thielcke 1986 for such cases). Garden Warbler song playback before the arrival On the contrary, Catchpole (1978) and Catch- of the latter species to the studyarea. As the winter pole & Leisler (1986) pointed out that birds learn quarters of the two species are geographicallysep - to recognize and respond to the songs of congeners arated, according to Matyjasiak (2005) Blackcap “who are regularlyheard and encountered in a males must recall the species association after 8 competitive situation”. These experienced birds months without contact with Garden Warblers. respond aggressivelyin subsequent heterospecific We were able to test the same hypothesis. Al- encounters. Catchpole & Leisler (1986) demon- though Black Redstarts behave territoriallyin win - strated a clear differential response of Reed War- ter areas (Cuadrado 1995) theycannot interact bler (Acrocephalus scirpaceus) to Great Reed with Redstarts during the winter. The Black Red- Warbler (A. arundinaceus) song playback at two start winters around the Mediterranean, whereas localities separated byonly5 km. Thus, theysug - the Redstart migrates to sub-Saharan Africa gested that local occurrence of interspecific ag- (Cramp 1988). As Black Redstart males respond gression can be explained onlybyindividual expe - aggressivelyin heterospecific experiments before rience with interspecific competitors. Our results the arrival of Redstarts, it means that the once- are consistent with these assumptions. The hy- learned aggression persists at least to the next pothesis of learning can well explain increased breeding season. According to Matyjasiak (2005), rates of interspecific aggression of the Black this long-lasting memorycould be an evolutionary Redstart in Bøeznice, where the two species come adaptation in cognitive abilities in migrants, be- into close contact. cause it mayallow birds to remember relevant op - Catchpole (1978) and Catchpole & Leisler ponents and avoid wasting time and energyevict - 160 ORNIS FENNICA Vol. 83, 2006 ing heterospecific intruders which pose no threat. nun lauluun vain alueilla, joilla nämä kaksi lajia We suggest that this “associations memory” could esiintyvät yhdessä. Tämä osoittaa, että mustalep- result in site-specific levels of interspecific aggres- pälinnut oppivat tunnistamaan kipailijoidensa lau- sion in species which are faithful to their breeding lun vain, jos kyseisten lajien yksilöt ovat tekemi- sites. In the Black Redstart, an extremelyhigh rate sissä keskenään. Alueilla, joilla tavattiin molem- of between-year site fidelity was confirmed pia lajeja, mustaleppälinnut reagoivat leppälinnun (Weggler 2000). lauluun jo ennen kuin leppälinnut olivat saapuneet Matyjasiak (2005) also assumed that the abil- talvehtimisalueiltaan. Mustaleppälinnut siis oppi- ityto identifyheterospecific competitors must de - vat edellisenä vuonna kohtaamiensa leppälintujen velop before the first breeding attempt, because perusteella yhdistämään niiden laulun kilpailuun yearling Blackcap males responded before the ar- resursseista. rival of the other species used in the playback ex- Tämän lisäksi vuoden ikäisten ja vanhempien periments. We were able to test this hypothesis koiraiden reaktioiden voimakkuudessa ei ollut more directlythanks to the age differences in plu - eroa. Tulos tarkoittaa sitä, että nuoret mustaleppä- mage colouration in the Black Redstart. Our re- linnut oppivat yhdistämään leppälinnun laulun kil- sults are consistent with the suggestions of pailuun jo ensimmäisenä syksynään ennen ensim- Matyjasiak (2005). We did not find any significant mäistä omakohtaista reviirikiistaansa leppälintu- differences between the heterospecific response of jen kanssa. yearling and older males, suggesting that young males are able to learn to recognize heterospecifics during the post-fledging period. References

Acknowledgements. We wish to thank to Miroslav Bobek, Catchpole, C. K. 1978: Interspecific territorialism and who amplified and standardized the song recordings of the competition in Acrocephalus warblers as revealed by two redstart species and to Vojtìch Jarošík and Simona playback experiments in areas of sympatry and allo- Poláková for help with statistical analyses. We are grateful patry. — Animal Behaviour 26: 1072–1087. to Ryan Rego for improving the English of this paper. Two Catchpole, C. K. & Leisler, B. 1986: Interspecific terri- anonymous referees provided valuable comments on ear- torialism in Reed Warblers: a local effect revealed by lier drafts of the manuscript. The data collection complies playback experiments. — Animal Behaviour 34: 299– with the current laws of the Czech Republic and has been 300. granted bythe Ethical Committee of the Universityof Cody, M. L. 1969: Convergent characteristics in sympatric South Bohemia, Facultyof Biological Sciences (License species: a possible relation to interspecific competi- No. 1020/943/A/00). The studywas funded bythe projects tion and aggression. — Condor 71: 222–239. of Ministryof Education of the Czech Republic (MSM LC06073, MSM 0021620828 and MSM 600 766 5801). Cramp, S. (ed.) 1988: Handbook of the Birds of Europe, the Middle East and North Africa. Vol. V. — Oxford University Press, Oxford. Crook, J. R. 1984: Song variation and species discrimina- Mustaleppälinnut tunnistavat kilpailijansa, tion in blue-winged warblers. — Wilson Bulletin 96: vaikka ne eivät olisi samaa lajia 91–99. Cuadrado, M. 1995: Winter territorialityin migrant Black Redstarts Phoenicurus ochruros in the Mediterranean Lintujen on pitkään oletettu oppivan tunnistamaan area. — Bird Study 42(3): 232–239. kilpailijansa myös muista lintulajeista. Tästä joh- Cucco, M. & Malacarne, G. 1999: Is the song of Black tuen reviirinhaltijat reagoivat aggressiivisesti Redstart males an honest signal of status? — Condor myös toisen lajin edustajia kohtaan silloin, kun la- 101: 689–694. jien elinalueet menevät päällekäin. Hiljattain on Emlen, S. T., Rising, J. D. & Thompson, W. L. 1975: A be- osoitettu, että yksilöt voivan oppia tunnistamaan havioural and morphological studyof sympatryin the kilpailijansa niiden ulkonäön ja ääntelyn perus- Indigo and Lazuli Buntings of the Great Plains. — Wilson Bulletin 87: 145–179. teella. Testasimme mustaleppälinnuilla oppimisen Ertan, K. T. 2002: EvolutionaryBiologyof the Genus merkitystä lajien välisessä kanssakäymisessä, lin- Phoenicurus. Phylogeography, natural hybridisation tujen pitkäaikaista muistia sekä oppimisen ajoittu- and population dynamics. — Tectum Verlag, Mar- mista. Mustaleppälintukoiraat reagoivat leppälin- burg. Sedláèek et al.: Heterospecific rival recognition in Black Redstart 161

Gil, D. 1997: Increased response of the Short-toed Tree- alityand character convergence. — Condor 78: 518– creeper Certhia brachydactyla in sympatry to the play- 525. back of the song of the Common Treecreeper C. Murray, B. G. 1981: The origins of adaptive interspecific familiaris. — Ethology 103: 632–641. territorialism. — Biological Reviews 56: 1–22. Gill, F. B. & Murray, B. G. Jr. 1972: Discrimination be- Murray, B. G. & Gill, F. B. 1976: Behavioral interactions haviour and hybridization of the blue-winged and of blue-winged and golden-winged warblers. — Wil- golden-winged warblers. — Evolution 26: 282–293. son Bulletin 88: 231–253. Grant, B. R. & Grant, P. R. 1996: Cultural inheritance of Orians, G. H. & Wilson, M. F. 1964: Interspecific territo- song and its role in the evolution of Darwin’s finches. ries in birds. — Ecology 45: 736–743. — Evolution 50: 2471–2487. Payne, R. B., Payne, L. L., Woods, J. L. & Sorenson, M. D. Grant, B. R. & Grant, P. R. 1998: Hybridization and 2000: Imprinting and the origin of parasite-host asso- speciation in Darwin’s finches: the role of sexual im- ciations in brood-parasitic indigobirds, Vidua chaly- printing on a culturallytransmitted trait. In Endless beata. — Animal Behaviour 59: 69–81. forms: species and speciation (Howard DJ, Berlocher Pelz, P. 1993: Pìvci I. [Passerines I.]. — Pelz-Biophon, SH, eds): 404–422. — Oxford UniversityPress, Ox - Prague. ford. Prescott, D. R. C. 1987: Territorial responses to song play- Hansen, B. T. & Slagsvold, T. 2003: Rival imprinting: back in allopatric and sympatric populations of alder interspecificallycrossfostered tits defend their territo - (Empidonax alnorum) and willow (E. traillii) fly- ries against heterospecific intruders. — Animal Be- catchers. — Wilson Bulletin 99: 611–619. haviour 65: 1117–1123. Price, T. 1998: Sexual selection and natural selection in Irwin, D. E. & Bensh, S. & Price, T. D. 2001: Speciation in bird speciation. — Philosophical Transactions of the a ring. — Nature 409: 333–337. Royal Society of London B 353: 251–260. Irwin, D. E. & Price, T. 1999: Sexual imprinting, learning Sedláèek, O., Fuchs, R. & Exnerová, A. 2004: Redstart and speciation. — Heredity 82: 347–354. (Phoenicurus phoenicurus) and Black Redstart (P. Kroodsma, D. E., Byers, B. E., Goodale, E., Johnson, S. & ochruros) in the mosaic urban environment: neigh- Liu, W. 2001: Pseudoreplication in playback experi- bours or rivals? — Journal of Avian Biology35: 336– ments, revisited a decade later. — Animal Behaviour 343. 61: 1029–1033. Simmons, K. E. L. 1951: Interspecific territorialism. — Landmann, A. & Kollinsky, CH. 1995: Territory defence Ibis 93: 407–413. in Black Redstarts, Phoenicurus ochruros: effects of Slater, P. J. B. & Catchpole, C. K. 1990: Responses of the intruder and owner age? — Ethology 101: 121–129. two Chaffinch species on Tenerife (Fringilla teydea Leisler, B. 1988: Intra- and interspecific aggression in and F. coelebs tintillon) to playback of the song of sedge and aquatic warblers. A possible case of acous- their own and the other species. — Behaviour 115: tical misidentification? — Vogelwarte 34: 281–290. 143–152. Lille, R. 1988: Art- und Mischgesang von Nachtigall und Slagsvold, T. & Hansen, B. T. 2001: Sexual imprinting Sprosser (Luscinia megarhynchos, L. luscinia). — and the origin of obligate brood parasitism in birds. — Journal für Ornithologie 129: 133–159. (In German) American Naturalist 158: 354–367. Lynch, A & Baker, A. J. 1991: Increased vocal discrimina- Slagsvold, T., Hansen, B. T., Johannessen, L. E. & Lifjeld, tion bylearning in sympatryin two species of chaf - J. T. 2002: Mate choice and imprinting in birds studied finches. — Behaviour 116: 109–126. bycross-fostering in the wild. — Proceedings of the Martin, P. R. & Martin, T. E. 2001a: Ecological and fitness Royal Society (London) B 269: 1449–1455. consequences of species coexistence: a removal ex- Sorjonen, J. 1986: Mixed singing and interspecific terri- periment with wood warblers. — Ecology82(1): 189– toriality– consequences of secondarycontact of two 206. ecologicallyand morphologicallysimilar nightingale Martin, P. R. & Martin, T. E. 2001b: Behavioural interac- species in Europe. — Ornis Scandinavica 17: 53–67. tions between coexisting species: song playback ex- Ter Braak C. J. F. & Šmilauer, P. 2002: CANOCO Refer- periments with wood warblers. — Ecology82(1): ence manual and CanoDraw for Windows user’s 207–218. guide: software for canonical communityordination Matyjasiak, P. 2005: Birds associate species-specific (version 4.5). — Microcomputer Power, Ithaca, N.Y. acoustic and visual cues: recognition of heterospecific Thielcke, G. 1986: Constant proportions of mixed singers rivals bymale blackcaps. — Behavioral Ecology16: in tree creeper populations (Certhia familiaris). — 467–471. Ethology 72: 154–164. Murray, B. G. 1971: The ecological consequences of inter- Weggler, M. 2000: Reproductive consequences of autum- specific territorial in birds. — Ecology 52: 414–423. nal singing in Black Redstarts (Phoenicurus ochru- Murray, B. G. 1976: A critique of interspecific territori- ros). — Auk 117(1): 65–73.