Corella,2008, 32(2\: 30-34 A POSSIBLETERRITORIAL AND NESTINGASSOCIATION BETWEENPIED AND GREYBUTCHERBIRDS Cracticus nigrogularis and C. torquatus AND THE YELLOW-THROAIEDMINER Manorina flavigula GRAHAM R. FULTON Centle for EcosystemManagement, Edith Cowan Unive$ity, Joondalup,WA. 6027, Australia. Email: $ahamf200 [email protected] Recefued:30 January 2006 This study demonstratedthat Yellow-throatedMineis Manorina flavigulaarc aggressivebirds that exclude other species of birds from their territories. However,they did not exclude Grey ButcherbirdsCracticus torquatus or Pied ButcherbirdsC. ,,grogula/s from two widely separatedsites in WesternAustralia. Concurrently active nests of Yellow- throated Miners and Pied Butcherbirdswere lound within 10-30 metres of one another at Westonia.Yellow-throated Miners, and Pied and Grey Butcherbirds perched close to each other without aggression.A territorial and nesting associationbetwoen these species is unexpected since both genera are aggressivetowards other species. Pied and Grey Butcherbirds may benetit from abundant arthropod resourcesthat are not exploited by miners, and in return, miners may benefitlrom the aggressiveabiliiy ofthe butcherbirdsto repulselarger nest-predators when miners cannot. The grouping of nests may aid all species in defendingtheir territoriesand may enhancetheir nesting success. INTRODUCTION METIIODS Speciesin the genus Manorina have been identified as Field sites birds that exclude other species from their terdtodes, sometimesleading to sole occupancyof a site (Dow 1977; Two field sites, Ejah and Westonia,were chosen with Loytn et al. 1983; Higgins et al. 20Ol). Inter-specific butcherbirdsand Yellow-throatedMiners presentat each.The teffitoriality has been report€d in Bell Miners Manorina sites were 563 kilometres apart to test if aIIy tedtorial melanophrys(Loyt et al. 1983; Clarke and Schedvin 1999), associations,between the two genem, applied over a broad Noisy Miners M. melanocephala(Dow 1977; Grey et al. geographicalarca. 1998), Yellow-throated Miners M. (Starks 1987) flavigula Ejahis an outcampat Mileura Station,about 800 kilometres and Black-eared Miners M. melanotis (Starks 1987; northeastof Perth;26" 24' S, I17"11'E.Mileuraisasheepand Mclaughlin 1990). cattlestation on the MurchisonPlains in the (semi-arid)mulga Despite the wealth of knowledge available on the Noisy zone of WestemAusftalia (seeDavies 1970, 1986).Ejah is a Miner and Bell Miner, and the rapidly expandingdata on the mesic areabecause of the runoff from an escaqrmentand is one Black-eared Miner, there has been surprisingly little of the few productive sites (with denservegetation) in the area. published on the agonistic behaviour of the Yellow-throated Observations were made over a four-hectare area: upon and Miner, despite its wide distribution across Australia. immediatelyadjacent to an escarpment(breakaway), up to and Yellow-throated Miners have been descdbed as aggressive at a dry ephemeralcreek. The creek was approximately150 to other birds (Mellor 1919), aggressive near the nest metres south of the breataway ald had denser vegetatiol than (Chandler 193'7), ot less aggressive than Noisy Miners the surroundingarea. The flora of the creek area comprised (Jeffery 1955). Eremophila spp.,Acacia spp. and Hakea spp. The dominant vegetationnear the breakawayconsisted of Acacia spp. and Butcherbirds Cracticus spp., catchlive prey including birds Eremophila spp.. as large as Common Blackbirds Turdus merula and Spotted Turtle-DovesStreplopelia chinensis (Pizzey and Knight 1997). Westonia(31' 18' S, 118'42'E) is locatedapproximately They are nest-predatorsidentified by photography (Major el al. 300 kilometreseast of Perth on the easternside of the central 1999),and havebeen observed taking nestlingsand adult birds wheatbelti[ WesternAusralia. It is situatedin 5 600 hectares (Hobbs 1981;Ta$urton 1991). of remnant bushland, known as Westonia Commons. Observations were recorded, over a foul-hectare arca, on the This study recorded inter-specific aggressionand nest edge of the small township in a suburbanarea and in adjacent positioning in two populations of Yellow-throated Miners, Salmon Gum Eucalyptus salmonophloia, Gimlet E. salubris irl WesternAustralia, to establishif they are less aggressive and Red Morel E. longicomis woodland. Yellow-throated towards butcherbirds than other birds and to detect if Mine$ nested at both ends of this study area and Pied nesting together might provide any mutual benefit. Butcherbirdsnested at one end with Yellow-throatedMiners. 30 June2008 G.RFulfoni Possible territorial and nestino association between Pied and Grev Butcherbirds and the Yellow-throated L4iner Field obseryations Aggre$ton A combinedtotal of 27 hoursof observationswas madeat Yellow-thrcatedMiners were aggressiveto all birds (14 both field sites.Four hours of observationswere madeat Ejah species)except butcheftirds that entered the study areas(Table (fiom 29 June through 2 July 2004) one hour eachon four l). They also mobbed the Galah Cacatua roseicapilla, momings ranging from 0745 hourc and finishing at the latest Australian Rirgneck Bamardius zonarius, Red Wattlebird by 1030hours. Twenty hoursof observationswere undertaken Anthochaera carunculata, Spiny-cheeked Honeyeater at Westonia(21 a']'d,23 Apdl, and fuom 22 to 24 September Acanthagenysrufogalarls, Australian Rayen Corvus coronoides 2004). In September,ten houls werc undertakel iII both the ar'dLittle Crow C. bennetti. moming and evedng between0630 0900 hours oyer four days and 1500 - 1700 hours on five days. In April surveys A Grey Butcherbird chasedoff an Australian Ringneck (at were undertakenfor one hour on 21 April and two hours 23 Ejah), which had been harassedby Yellow-throated Miners but April: all were in the moming after sunrise.Old nestswere not displaced. At Westonia, a Red Wattlebird and a Westem identified becausethey were identical to the nests that were Corella Cacatua pastinator that had not been deterred by either being used or being built by Pied Butcherbirds-In Yellow-throatedMiners, within 15 metresof the inter-specific grcup addition, (StephenDavies pers. comm.) identified the old of nests, were subsequentlychased away by Pied Butcherbirds. nestsat Ejah as thesehe knew were built and used by Grey Butcherbirds.He also advisedme thatYellow-throated Miners DISCUSSION and Grey Butcherbirdshad occupied this same site for 45 continuous yeam. Yellow-throatedMineIS were considered An associatiol bet:vteen Manorind spp. and the Grey acting aggressivelyif they made deliberate contact with Butcherbirdis supportedby a considerableamount of anecdotal anotherspecies; swooped and causedanother species to leave data(Table 2), but thereis little evidenceof minersassociating the site, chasedanother species from the immediatearea; or if with Pied Butcherbirds(Table 2). Piper and Catterall (2003) one or more birds perched close to another species and reponed Pied and Grey Butcherbirds, along with other large harassedit by squawking,calling or by making short flights species,may be toleratedto some degrceby Noisy Mine$. toward it. Amold (2000a) did not see either Grey or Pied Butcherbirds mobbed by Noisy Miners, although other potential predatoG Yellow throated Miner's teritories were thoroughly were. In the present study, Yellow-throated Miners excluded searchedfor all nests.Nests were detectedby eitherfollowing other species ftom their own teritories and they did this birds that madercpeated flights to the samelocation, or while selectively,while exhibiting toleranceor acceptanceof Grey surveying.Distances between nests in the inter-specificgroup and PiedButcherbirds (Table 3). of nestsat Westoniawere measuredwith metle long stddes. The distanceof the two miner nestsgreater than 100 metles Many birds will toleratemost other birds perchingclose by, distantfrom the inter-specificgroup of nestswere estimated. except tbr n€st-predators and camivores (Pavey and Smyth A nest was consideredactive if it containedeggs, the female 1998;,\6o16 2000b;Fulton unpub.data). Close perchingard was laying or incubating. tolerantbehaviour described here are unexpected betweel such aggressivespecies as Yellow-throatedMiners, and Grey and An abundanceindex was calculatedby taking the meanof Pied Butcherbirds. Birds as predators of other birds typically hourly bird counts. To avoid double-countilg of any use stealth or surprise to attack (e.g. Wood 2000). When a bird individuals in the hour, the total hourly count was takenonly tums its back on a known predatory species it invites from the maximum numberof birds that could be seenat any opportunistic predation, or at the very least an aggressiveattack. one time. This figure is likely to underestimatethe true totals BreedingYellow-throated Miners tumed their backs on Pied of larger groupsof birds that are constantlymoving aboutthe Butche6irdsafter perching by their sidesand while foragingon study area. the ground together.It is doubtful that breedingYellow-throated Miners would be naiveabout the dangerof this action;it seems RESULTS reasonable to interpret this behaviour as 'trusting' and more Grouped nests than simply tolerant. The two most A group of four concurrently active nests, two Pied significantfactors affecting nest successare food and predation(Collias and Collias 1984; Martin i988a, Butcherbirdsand two Yellow-throatedMirlers, were detected 1988b,1992, 1995;Collias 1997).Butcherbirds take a vadety in WestoniaCommons. Two Yellow-throatedMiner nests(one of prey, which is dominated by larger invertebrates