Table Of Content

Birds in the urban environment BOCA Western Port Survey: long-term monitoring of waterbird numbers Xenia Dennett1 and Richard H Loyn2 1BirdObservation&ConservationAustralia,POBox185,Nunawading,Victoria3131 ArthurRylahInstitute,DepartmentofSustainabilityandEnvironment, 123BrownSt,Heidelberg,Victoria3084 Abstract Since 1973volunteers from the BirdObserversClubofAustralia (BOCA, formerlyknown asBirdObservers Club),havecountedbirdsseveraltimesayearattheirhigh-tideroostswithinWestern Port, aRamsardesig- adnanattdaemdfeosnrittsei.ooTmnheseossfoutmrhveeefsyapfcetocociruesssertsehsaoptnohnwasavitebelrdebeicfrolrdinstehade,nsdeinsnchuromerbaeseberidsrd.osr(iTrnheetmhVaeiicnttioedrdiaalcnloyNnaistntufralanultiesnitnce1nd2u6am(r3be)ae,sr2.0s0T9hd,iusr99ip-na1gp07et)rhisprpeesreinotds Keywords:waterbirds; shorebirds; survey; Western Port; BirdObservers Club ofAustralia Introduction Western Port isalargeshallowembaymenteast to focus on waterbirds and shorebirds in the ofMelbourne in south-east Australia. It is one tidally influenced areas ofthe Bay (Loyn 1978; ofthethreemost importantsitesforshorebirds Dann et al 1994; Loyn et al 1994; Loyn 2002; inVictoria (Watkins 1993)andisaRamsarsite. Loyn andDennett2008). Most ofthe bayis shallow, has extensive mud- Since 1973, teams of BOCA volunteers and flats at low tide and is fringed by mangroves others, have gathered on a predetermined day (Avicenna marina) and saltmarsh. There is at some 20 regular sites within the Bay, plus some industry and commercial shipping cen- other conditional sites, prior to the daytime tred around Hastings in the west with a deep- hightide. Allwaterbirdsarecountedandnum- water port and shipping channels maintained bers recorded. Counts are made at least three bydredging. times a year, in February when the Palaearctic Western Port has three marine parks and is shorebirds are preparing to migrate to their very popular for recreational boating and fish- breeding grounds in the far Northern Hemi- ing. Phillip Island, at the southern edge ofthe sphere and when others use Western Port as a Bay, is a major tourist attraction, particularly summer refuge; in June/July for resident and in summer. French Island in the centre ofthe over-winteringmigrantsandin November/De- Bay is twice as large as Phillip Island, but it is cember when post breeding and juvenile Pal- sparsely populated: the French Island National aearctic shorebirds have returned to moult and Park covers two-thirds of the island. Both is- spendtheAustral summer. lands have extensive freshwater and brackish As a consequence of this continuous, long- wetlands. running survey the significance of Western Western Port provides valuable roosting and Poit for birds has become widely recognised. foraginghabitats for shorebirds and waterbirds It is listed under the Ramsar Convention on with rich areas of mangroves, saltmarsh and Wetlands and is part ofthe Shorebird Site Net- intertidal mudflats. Western Port has four wet- woikfortheEastAsian-Australasian Flyway. In lands types: permanent saline and semi-per- 2002, it was included as part ofthe Biosphere manent saline around the Bay, deep freshwater Reserve for Western Port and Mornington Pe- omnaTrhFserheeBnsOchaCnaAdndpWeePrshitmlealrninpenIPtsolraotnpdeSsun.rvferye,shiwnaitteiarteadrebays atnuinrndesuiAlsuaas,tkhreaayslimbaoenSeihntoorrreeibcinorggdnsiiCztoeendfsoberyrPvaWaltaWieaoFrnctfPiorcrojaNenacd-t Richard Loyn in 1973, began with the aim of Australasian shorebirds. locating major high-tide roosts and counting The wetland avifauna ofWestern Port can be birds whilst they were concentrated at those broadlycategorised as: roosts. At low-tide, waterbirds are widely dis- • waterbirds, includingthefishers (cormorants, persed overvast areasofmudflats,makingreg- pelican and terns), waterfowl (ducks, grebes, ular counts impractical. The survey continues swan, etc.), crakes and rails, gulls and large Vol 126 (3) 2009 99 a BiodiversitySymposium SpecialIssue wading birds (herons, ibis, spoonbills and erycover forfingerlings and otheraquatic spe- egrets); cies. Hence‘fishers’suchasPiedandLittlePied • international migratory shorebirds, compris- Cormorant and Australian Pelican all showed ing Palaearctic species breeding in Asia and similarsignificantdecreasesfollowingthisvery theArcticandoneAustralasianspecies, Dou- seriouslocal event. ble-banded Plover, breeding in mountains of Throughout Western Port the sea beds are theSouth IslandofNewZealand; variable,withsignificantregionaldifferencesof • Australian breeding shorebirds, including sand, silt and mud substrates and water flows. dotterels,plovers,avocet,stilts,oystercatchers Various species take advantage ofthese differ- andlapwings; and ent niches. Long term monitoring over three • bushbirds, associated with wetlands, such as seasons each yearhas shown interestingtrends songbirds, raptors, kingfishers andparrots. inshorebird numbers. Someexamplesfollow. To satisfythe Ramsar Convention criteria for identifying areas of international importance Seasonalandcyclicchanges for shorebirds in Australia, an area must sup- All species show some seasonal changes on an port one per cent or more ofthe world popu- annual basis. The most marked are obviously lation of a particular species or subspecies of the migrating shorebirds, but most other spe- shorebirds,orsupport20000ormoreindividu- ciesalsoshowconsistentseasonalvariationdue als ofthat species or subspecies. As a result of to climatic and breeding requirements. For ex- the BOCA surveyand some additional studies ample, BlackSwans arepresent throughout the Western Port was recognised as having inter- year, but their numbers fluctuate and show a nationally significant numbers ofEastern Cur- seasonal cycle. Their counts are lowest during lew, Common Greenshank, Curlew Sandpiper, winter and early spring (Figs. 1 and 2) when Red-necked Stint and Double-banded Plover theyarebreedinglocallyonadjacentfarmlands and a significant national population ofPacific and swamps. Most locally breeding waterbirds Golden Plover(Watkins 1993). show a seasonal pattern with minimal num- The smallest and most numerous Palaearc- bers in the winter-spring breeding season and tic waders in Western Port and Australia are maximum numbers in summer or autumn. Red-necked Stints and Curlew Sandpipers. Exceptions include the Great and Little Black Observations of these small waders, banded Cormorants, which tend to be recorded most by Victorian Wader Study Group, show their in spring. migration routes from Western Port to Sibe- Manyoftheinternationalwaders breed in Si- rian breeding grounds occur in four or five berian regions where lemmings and voles also stages, with ‘refueling’ stopovers in north-west breed. Thesesmallrodentsshowcyclical‘boom Australia (Broome), south-east Asia, further andbust’breedingevents.Whentheirnumbers north in eastern China and perhaps inland Si- arehigh,predatorssuchasowlsandfoxes,have beria. Larger waders, Bar-tailed Godwits and plenty of food for their young, but when the Red Knot make fewer stopovers (Minton et al lemming numbers crash they seek other food 2006). sources, including eggs and chicks ofwaders. Overseas factors such as loss offeeding sites Consequently there is a reduction in juvenile due to land reclamation (as at Saemangeum in waders migrating southwards. These events Korea), reduction in water flows due to dam tend to have a periodicityofabout threeyears. formations, and weather events causing early These trends and others (Loyn and Dennett orlatethaws/melts,mayallimpactontheenvi- 2008, Fig. 3) can be seen in some ofthe West- ronmentofmigratingbirds. ern Port data, for small waders such as Curlew Whatotherfactorsmaybeoccurring?Onelo- Sandpipers and Red-necked Stints. caleventintheearly 1980s,occurringthrough- Earlydecreases out Western Port for unknown reasons, was a Grey-tailedTattler marked decline in seagrass {Zoster spp). Sea ThisPalaearcticwaderismostcommonlyfound grass is essential as a primary food source for overwintering in northern Australia, with Vic- some species, such as the herbivorous Black toriaandTasmaniaattheendofitsrange.Since Swan, and provides essential protective nurs- the survey began there has been a dramatic decrease in their numbers. In the 1970s, 60-81 100 TheVictorianNaturalist Birds in the urban environment Fig.l. BlackSwansbreed inlocalfreshwaterswampsanddams. PhotobyXeniaDen- nett. Black Swan — — February * Winter November | Fig. 2. BlackSwan counts from BOCA Western Port Survey from 1974 to 2007 showing seasonalvariations withmaximumnumbersin February,thesummerrefugeseason. Vol 126 (3) 2009 101 BiodiversitySymposium SpecialIssue February counts for3 paloearetie wader species — — — 4 Red-neckedStint Curlew Sandpiper Eastern Curlew Linear(Red-neckedStint) Linear(Curlew Sandpiper) Linear(Eastern Curlew) Fig.3. Total February counts for three species ofpalaearctic waders during the BOCA Western Port Survey period 1974 -2007. Trendlineshavebeen added to showan apparent increasein Red-necked Stint,asignifi- cantdecreaseoftheslightlylargerCurlewSandpiper,andaslowsteadydeclineinthenumbers ofthelargest waderEasternCurlew. individuals were counted regularly in Western Black Swans feed directly on the sea grass Port on their return from the Arctic. In the growingin shallowwaters, and thesudden loss 1980snumbersdroppedtoaround 10,by 1990s ofseagrass,intheearly 1980s,severelyaffected onlytwoandinthelastdecadetherehavebeen numbers. Since then, there has been some in- veryfewrecords. However, therehas alsobeen crease in sea grass and local numbers ofBlack a similar decrease throughout northern Aus- Swan are again increasing around Rhyll and tralia (Kearney et al 2008) and the East-Asian Observation Point. But some beds in Western Australasian Flyway, solocal eventsinWestern Portstillshownosignsofrecovery,forexample Port are unlikely to be a major factor in the around the north-east section adjacent to Yal- local decline. These birds often roost in man- lock Creek (BOCA 2003), where water turbid- groves (makingcountingdifficult)aswellasin- ityin this areaisveryhigh. Is this reducingthe termittently moving their roosting sites (Min- amountofsunlightessentialforphotosynthesis ton 2000). It is thereforepossible that they, and andplantgrowth? otherbirds, maysometimesbeoverlooked. Australian Pelican numbers in February also droppedfromanaverageof200priortothesea SilverGulls These scavenging omnivores are present grass loss in 1983, to about 50 a decade later, throughout the year, with highest numbers in and are still continuing to struggle upwards November and February. In the 1970s their (Fig. 5). These ‘fishers’ breed in inland Aus- numbers were increasing, until the open rub- tralia in saline waterways, and there have been bish tip at Hastings was closed. A significant significantbreedingeventssincethenatseveral major inland water bodies. Could these breed- decrease followed, and as other regional tips ingeventshave‘depleted’ thecoastalnumbers? were also closed their numbers have declined (Fig. 4). Active management measures have Numbers of Little Pied Cormorant, another fisher affected by the sea grass crash, showed also delayedtheirrecovery. similar declines and have not recovered (Figs. 102 TheVictorian Naturalist Birds in the urban environment 6 and 7). The larger Pied Cormorant declined seemed to hold up well until the early 1990s initially, but showed a later recovery. These (Dann et al 1994), but have declined subse- birds are able to fish in deeper waters outside quently(Fig.3). Probablyavarietyoffactorsare Western Port. responsible, including events en route and on thebreedinggrounds. Recentdecreases At least two species ofinternational migratory Generalincreases wader have decreased in recent years, as in- Red-neckedStint dicated below. These declines are usually con- Observations on this, the smallest migrating sidered to be related to events on the breeding wader, do not show the obvious downward grounds or events such as loss of habitat on trend shown by most other Palaearctic waders, theireast Asian migration routes. and there even appears to be an increase (Fig. 3) in numbers. This is in striking contrast to CurlewSandpiper the slightly larger, but still very small, Curlew Ofall the migrating wader species these small Sandpiper mentioned above. Both have a rath- waders (Fig. 8) have shown the largest decline er similar northern migration route, although throughout the East Asian-Australasian Fly- CurlewSandpiperstendtotakea morewestern way. In recent years a lack ofjuvenile birds in route on theirsouthward migration (Minton et recapture studies is indicative of a significant al. 2006). Whyarethesetrends occurring? decline in breeding success, in addition to the normalcyclicalpattern (Fig. 3).Thereasonsfor Bar-tailedGodwit thisare not known. Although most data from the east coast show a long-term decline in numbers, Western Port Eastern Curlew figures are more encouraging with a general Since the 1980s all counts in south-east Aus- upward trend to approximately double the tarnadliaClheamveenssh,o2w0n06a).coNntuimnbueirngsdienclWiensete(GronsbPeolrlt numbers found in early years (Fig. 9). Why is this? Vol 126 (3) 2009 103 BiodiversitySymposium SpecialIssue recovered. not have still and 1980s early in collapse grass sea the Pelican to prior declining Australian were Numbers variations. seasonal showing Pelican Australian siiinoa 5. Fig. 104 TheVictorian Naturalist Birds in the urban environment Fig.6. LittlePiedCormorantfeeds on fish and is heavily dependent on food stocks inshallow regions. Photograph from BOCA collec- tion. Fig.7.LittlePiedCormorantcountsshowsomeseasonalvariationeachyear,butnumbersdecreasedaftersea grasslossesin 1980s,withlittlerecovery. Recentarrivals curred in the bay until June 1991, when seven Red-necked Avocets have made a dramatic Red-necked Avocets were counted in the Pio- appearance in Western Port counts in recent neer Bay area. No further birds were recorded years. These are Australian endemic, breed- until July 1994when 760birdswerecounted in ing waders, with a characteristic upturned bill thesamearea, andatthe Septembercountthey used to sieve their aquatic food ofsmall crus- numbered 850 before fallingto 370 in Novem- taceans, worms and molluscs. They rarely oc- ber 1994.Nobirdswerepresentinthefollowing Vol 126 (3) 2009 105 BiodiversitySymposium SpecialIssue Fig.8. SomeCurlewSandpipers migratefrom Siberianbreedinggroundstospendthe austral sum- merinWesternPortwheretheymoulttheirwornplumageand‘fatten-up’ beforereturningtobreed inthefollowingyear. PhotobyXeniaDennett. Fig.9. Bar-tailedGodwitisoneofthefewspeciesofpalaearcticwadertoshowanincreaseinnumbers inWestern Port. 106 The Victorian Naturalist Birds in the urban environment February. Since then this pattern of birds oc- References curring in Pioneer Bay from winter through to BOinCgAwe(t2l0a0n3d)bWiirdnsgs19o7v3e-r20W0e3s.te(rBnirPdorOtb:stehrrveeerdsecCalduebsosfurAvuesy-- November has become established, except in tralia,Reportno.10). 2000 and 2007 when no avocets were counted. DannP,LoynRHandBinghamP(1994)Tenyearsofwater- dBeecpaeunsdeindgatoens sfuoirtatbhlee ctioduenstsanvdardyayss,omweewhmaaty, GobgsuiblreldlslcaonKudnattnsedrinnsC.WleAeusmstetenrrsanliRPaon(rt2B,0i0rV6di)ctWPoaortipcauh,lea1rt9i71o35n-,8m33o5.n1Ii-It:3oW6ra5i.dnegrsi,n miss early or later arrivals as was possibly the Australia: some insights after 25 years and future direc- case in June 2000 (count done 17 June). We Ketaironnse.yThB,eSHtialstl5e0,m1A62-a1n7d5.Clemens R (2008) Report on can speculate on other possible reasons, but populationmonitoringcounts2007andsummer2008.The favourable food sources at appropriate water LoSytinltR5H4,(5149-7688).AsurveyofbirdsinWesternportBay,Victo- levels andaprotectedhabitatare probablyvery ria,1973-74.Emu 78, 11-19. important. LoynRH.(2002)ChangesinnumbersofwaterbirdsinWest- Other data from long-term avifauna studies eInrnLePoNrat,tuVriacltiosrtiea,inovWeerstqeuranrtPeorrtof18a0c2e-n2t00u2r.y(E1d9s73N-1a9n9d8).P have recently been published (Olsen 2008), Macwhirter,SaglioccoJLandSouthwoodJCommemora- much of which, as is the case with our data, tiveSeminar, 13-14April2002. hBaOsCbAeenWeosbtteairnnedPobrytdSeudrivcaetyedhavsolaulnrteeaerdsy.pTrhoe- LobfyionrwdlRHcao,nudnDtlasanrngienPwWaaednsitdneBrginbnigProhdrsat.,mAVPuisc(tt1ro9ar9li4ia)a,nT1eB9in7r3yd-e8aW3ra:stcIo.hfeWwraattee1rr5--, vided much useful information, particularly 333-350. relating to seasonal and longitudinal trends. LoIynnTRhHeSatnadteDoefnAnuestttraXl.iaW’satBeirrbdisr2d0s0o8f,Wpepst2e5r-n26P.orEtd.(P2e0n0n8y) Some factors are known to be operating at the Olsen (2008)SupplementtoWingspan, 18,no.4,Decem- local,regional,nationalandinternationallevels ber. whilst others are unknown. But without these MintonC(2000)Wadersroostinginmangroves.TheStilt37, 23-24. daantdaaotnteempctantnoomtabneaggientthoisavsekryquceosmtpiolnesx,,pflraang,- Mi(n2t0o0n6)C,MiWgarhaltiJ,onJesrsooupteRs,oHfaswsaedlelrCs,CwohlilcihnssPpeannddGthiebbnsonH-. ileand fascinatingenvironmentfor all who use OlbsreenedPin(g20s0e8a)soTnhienSAtuastteraolifaA.usTthrealSitai’lst5B0i,rd1s352-010587..Supple- tith.ePgeroepaltee,stproilslkustitoonthaenbdiopdeisvtesrspitryoboafbWleystpeorsne WamttiekonintnsitnoDAWu(is1nt9rga9sl3pi)aan.A,AN1u8as,ttirnoaonl.aa4ls,iPaDlneacnSehmFoborererbS.ihrodreSbtiurddieCsonGsreoruvpa,- pPoerntdeanntduitpsofnutiutref,orifncolouddianngdtshhoesletesro—vtehreyadvei-- RFooyraNlatAuurset.raRlaAsOiaUnORrenpiotrhtolNoog.ic9a0l.UnionandWorldFund fauna. Acknowledgements It is a pleasure to thank all the manyvolunteer ob- Received15January2009;accepted4June2009 serverswhohavetakenpartoversomanyyears,and especiallyto the BOCA coordinators and othersup- porters,friendsandcolleaguesandalsotoLaurieLiv- ingformaintainingthedatabase. One Hundred Years Ago BIRD DAY.—The first Bird Day instituted by the Education Department for the benefit ofthe scholars attendingtheStateschoolsofVictoriawascelebratedonFriday,29thOctober.Aspecialprogrammeofles- sons,dealingwithvariousaspectsofbirdlifeandlayingparticularstressontheirprotectionandpreserva- tion,wascarriedout. Inthesmallerschools,wherepossible,excursionsweremadetolocalitiesfrequented bybirds, andlessonsgiven in thefield. In themetropolis,asthiswas impossible, theservicesofanumber ofnaturalhistoryenthusiastsweresecured,andpracticaldemonstrationsonthevalueofbirdsweregiven bymembersofthe FieldNaturalists’Club,theOrnithologists’Union,andtheBirdObservers’Club,tothe seniorclassesofthesuburbanschools.Onthewhole,themovementwasasuccess,anditishopedwilllead tomoreinterestinourfeatheredfriends,withoutwhoseaidhumanlifewouldalmostbecomeimpossible. AdvantagewastakenofthedaytoinauguratetheGouldLeagueofBird-Lovers,and some50,000children handed in theirnamesaswillingtoobserve itsprecepts.Wetrust thismovementwill,astheyearsrollby, greatlylessen thedestructivepot-huntingwhichtakesplaceoneveryholiday. From The VictorianNaturalistXXVI,p.95,November 1909 Vol 126 (3) 2009 107