Waimakariri River Bird Survey Summary 2018
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Waimakariri River Bird Survey Summary 2018 Black-billed gull chicks – Photo: Nick Ledgard
Transcript of Waimakariri River Bird Survey Summary 2018
WaimakaririRiverBirdSurveySummary2018
Black-billedgullchicks–Photo:NickLedgard
The2018WaimakaririBirdSurveyTheWaimakaririRiverisknowntobeahabitatofoutstandingsignificanceforthreatenednativebirds.IthasbeenshowntosupportalargebreedingpopulationofWrybill(Anarhynchusfrontalis),BandedDotterel(Charadriusbicinctus),Black-frontedTerns(Chlidoniasalbostriatus)andBlack-billedgulls(Larusbulleri).Youcanreadmore(andwatchashortvideo)aboutthismightyriveranditsbirdsontheBRaidwebsiteatthislink.ThisistheninthyearofsurveyingofwhatisreferredtoastheMid-WaimakaririRiversurvey.Pastsurveyshaveoccurredin1980,1999,2001,2006,2007,2008,2009&2017.ThissurveyincorporatesfoursectionsfromtheGorgeBridgedowntotheSouthHighway1Bridge(Figure1).Theupperriversurveyisundertakenseparately,coveringgroundbetweentheBealeyRoadBridgeandtheEskRiverconfluenceatthetopoftheWaimakaririGorge(reportsavailableontheBRaidwebsite).BirdsbelowtheSouthHighway1BridgearesurveyedbytheChristchurchCityCouncil.The2018surveyranoverfourdaysfromOctober30thtoNovember2nd.Twenty-fiveparticipantstookpartinthesurvey,coveringatotalofjustover50KMofriverbed.Thesurveybeganwithanominousforecastwhichunfortunatelydiddeliveronitspredictedrainandwind.After5kmthevaliantparticipantsbecamewetandcold,andjetboatingconditionstenuous.Thecorrectcallwasmadetoretreatfortheday.Ultimatelythismeant10kmoftheriverdidnotgetsurveyedasthehighflowswhichfollowedDay4madereturningtosurveythisstretchunwarranted.Thehighflowswouldhavecausedmostbirdstomoveofftheriver,eventuallyresettlingindifferentlocations(seeFigure2).Theremainingthreesurveydayswerelargelyfine,thoughtheoddshowerandsoutherlychangereiteratedthehighlychangeablenatureofthebraidedriverenvironmentwhichtherivernestingbirdsmustcontendwithduringtheirspringbreedingseason.Unfortunately,mostoftheobservednestingbirdswouldhavelosteggsandchicksshortlyfollowingthesurveyafterheavyrainsinthecatchmentheadwatersresultedtwohighflow/floodevents.Giventhesehighflowsoccurredearlyinthenestingseason,thebirdswereexpectedtore-nest.SurveydataissharedwiththelocalbraidedriverbirdadvocacygroupBRaid(http://braid.org.nz/)andtheDepartmentofConservation,whocollatesallbraidedriverbirdcountdatasets.Thesedatasetsprovideimportantinformationontheuseoftheriverbythebirdspecies,informingrivermanagementdecisions,useandagencyresourcingofconservationactivities.Forthenextmonthphotographssharedbyparticipantsfromthe2018surveymaybeviewed(andaddedto)here.
Day StartPoint EndPoint Distancetosurvey(asthecrowflies)
Day1 Gorgebridge CooksRoad 15.2KMDay2 CooksRoad ThompsonsRoad 11.4KMDay3 ThompsonsRoad HerewoodCrossbank 14.8KMDay4 HerewoodCrossbank SH1Bridge 11.6KM
Figure1:Mapshowingthefourmainsectionsoftherivercoveredbythesurvey.In2018thesesectionswerebrokendowninto1kmunitstoallowformoreaccuratespatialreportingofthebirdcounts.
Figure2:RiverflowdatarecordedatWaimakaririGorgeduringthesurvey(maingrapharea)withthelongerpreandpost-surveyflowcontextshownbelow.Thebluehighlightedsectionshowsthesurveyperiod(Oct30th–2ndNov).
Keyobservationsfrom2018GeneralobservationsTotalbirdnumbersweregenerallyhigherthanthepre-2018surveyaverage.NotablynumbersofBlack-frontedTern,Black-billedgull,Wrybill,PiedStiltandWhite-frontedTernwerehigh(Figure3).Speciesspecificobservations1SeeTable1,2&Figure4forrecordedyearlycounts.Table3providescountsbythe1kmunitsadoptedduringthe2018survey.Ngutuparore–Wrybill-Anarhynchusfrontalis(NationallyVulnerable;Populationestimate:5,000-5,500)ArecordnumberofWrybill(n=252)werecountedwithinthefoursectionsthisyear;thehighestcountrecordedduringthissurveytodate(pre-2018average=82).NumerousKMunitshadmorethantenWrybillrecorded,withthegreatestdensityoccurringwithinSection3.Tūturiwhatu-BandedDotterel-Charadriusbicinctus(NationallyVulnerable;Populationestimate:50,000)Atotalof494BandedDotterelwerecounted.Thisisslightlyhigherthanlastyear’scountof439andwouldhavebeenhigherhadthe10kmmissedwithinSection1beensurveyed.Dotterelwereobservedinall1kmunitssurveyed,withhighestnumbersoccurringwithinSection3includingacountof27individualswithinKMunit40.Tarapirohe-Black-frontedTerns-Chlidoniasalbostriatus(NationallyEndangered)Arecord763Tarapirohewerecountedthisyearcomparedto312lastyearandapre-2018averagecountof299gulls.ThetwolargestcolonieswerelocatedwithinSection3withcountestimatesof200and100individuals.Tarāpuka–Black-billedGulls-Larusbulleri(NationallyCritical)Almost3,000Tarāpukagullswerecountedontheriverthisyear,withacolonyofapproximately2,000birdsrecordedwithinSection4(NZTM1564550,5190960).Thisisthelargesttotalcountofthisspeciesduringthissurveythusfar.Karoro–SouthernBlack-backedGulls-Larusdominicanus(NotThreatened)WildlifeInternationLtd(WMIL)havebeensurveyingtheSBBGandconsequentlytheirsurveyorsdidnotspendtoomuchtimetryingtogetaccuratecountsofthisspecies.The2018WMILreport(availablehere)reported4,071pairsofSBBGonthelowerWaimakarririthisyear(surveyareaincludesriverbedaboveandbelowthesectionsreportedonhere).Theauthorsnotethatwhilethespreadofcoloniesthisyearwassimilartothe2016and2017surveys,therewereagreaternumberofsmallcoloniesandthatthismaybeinresponsetoongoinggullcontroloperationscausingthegullstodispersemorewidely.White-wingedblacktern-Chlidoniasleucopterus(Native,NorthernHemisphereMigrant)BelowthestartofSection3atThompsonsRoadsixWhite-wingedBlackTernswere(excitedly)recorded.Itisestimatedthatlessthan20ofthesebirdsvisitNewZealandannuallyandtheobservationofthisbirdinitsbreedingplumagemakesthispossiblythefirstsuchrecordofthespeciesbreedingontheWaimakariririver2.
1PopulationandThreatStatusisfromNZBirdsOnline:http://nzbirdsonline.org.nz/2“Inthenorthernhemisphere,white-wingedblackternsbreedcoloniallyinmarsheswithnestsonfloatingorshorevegetation.ThefourNewZealandbreedingrecordsarefromthelowerRakaiaRiver(1917,3chicksfledged),OpihiRiver,SouthCanterbury(December-February1973-74),upperAcheronRiver,Marlborough(December2012),andnearTwizel(January2015).In1973-74,asolitarypairbredontheedgeofasmallblack-frontedterncolonyatalagoonfrontatthemouthofashingleriverbed.Thefirstnestfailedandasecondnestproducedachickwhichappearednottohavefledged.The2012and2015breedingrecordswerealsoofsinglepairsassociatedwithblack-frontedterncolonies,withbothnestsfailingduetopredation.”-NZBIrdsOnline
Figure3:Total2018adultbirdcountsofthe12mostabundantspeciesontheWaimakariririvercomparedtotheaveragesurveycountofprevioussurveys(1980,2006,07,08,09,17&18).*ExcludingSouthernBlack-backedgull.
0 500 1000 1500 2000 2500 3000 3500
White-facedheron
Feralpigeon
White-frontedtern
Paradiseshelduck
Piedstilt
SIPO
Wrybill
Duckspecies
Black-billedgull
Black-frontedtern
Canadagoose
Bandeddotterel
Spur-wingedplover
2018TotalMostCommonBirdSpecies*Count&Averagepre-2018SurveyCount
AveragePre-2018 2018
Table1:Totaladultbirdcountsofspecies1980,2006,07,08,09,17&18.Speciesareorderedfromthehighesttolowestcountaverageacrossallyears.Speciesorderedbyaveragecountacrossallyears(inc.2018),withthepre-2018averagecountshownasacomparisonfor2018counts.Notethatsurveysundertakenin1980&2006didnotcoverSection4.SeeTable2foracomparisonacrossyearsforcountsacrossSections1-3.Species 1980 2006 2007 2008 2009 2017 2018 Average
Pre-2018
Southernblack-backedgull
NC 4019 4801 8763 7723 N/C* N/C* 6327
Spur-wingedplover 52 22 343 1221 115 1754 839 585Black-billedgull 42 201 18 70 9 1085 2907 238Bandeddotterel 309 116 419 634 246 439 494 361Black-frontedtern 74 247 312 423 424 312 763 299Canadagoose 170 13 537 497 549 311 237 346Wrybill 45 26 73 78 105 164 252 82Duckspecies 111 157 85 122 106 44 73 104SIPO 166 27 48 99 45 105 70 82Piedstilt 58 0 26 65 106 42 166 50White-frontedtern 0 0 28 23 0 37 113 15Paradiseshelduck 8 0 19 49 45 32 15 26Feralpigeon 0 7 0 0 0 61 30 11White-facedheron 12 0 11 14 3 26 19 11Welcomeswallow 0 10 0 4 13 29 0 9Blackshag 8 17 4 2 4 3 1 6Harrier 0 2 1 1 1 21 7 4Pipit 0 9 0 5 2 11 1 5Littleshag 0 0 0 12 1 2 0 3CaspianTern 4 0 0 1 0 2 3 1piedshag 0 0 7 0 0 1 1 1White-wingedblacktern
0 0 0 0 0 0 6 0
Kingfisher 0 1 0 1 0 1 1 1Black-fronteddotterel
0 0 0 1 0 0 1 0
Commontern 0 0 0 0 0 0 0 0Red-billedgull 0 0 0 0 0 0 0 0Turnstones 0 0 0 0 0 0 0 0
*Willis&Bell(2018)reported4,071pairsofSBBGonthelowerWaimakarririthisyear(surveyareaincludesriverbedaboveandbelowthesectionsreportedonhere).In2016thenumberreportedwas5,015pairsandin20173,031pairs.The2018reportmaybeviewedhere.
Figure4:Birdspeciescountsoversurveyyears1980,2006,2007,2008,2009and2017&18ontheWaimakaririRiver.Averagecountshownincludesallyears.Notethatsurveysduring1980and2006didnotincludeSection4and10kmofSection1during2018wasnotsurveyedduetopoorweather.SeeTable2belowforacomparisonofallyearsforSections1-3.
Table2:TotalbirdcountsfromSection1-3(GorgetoHarewoodCrossbank).Species 1980 2006 2007 2008 2009 2009 2017 2018Black-frontedtern 74 247 312 283 424 444 198 602CaspianTern 4 0 0 0 0 0 2 3White-frontedtern 0 0 28 8 0 200 34 53Commontern 0 0 0 0 0 0 0 0White-wingedblacktern 0 0 0 0 0 0 0 6Black-billedgull 42 201 18 41 9 1509 514 886Red-billedgull 0 0 0 0 0 0 0 0Bandeddotterel 309 116 419 505 246 246 373 388Black-fronteddotterel 0 0 0 1 0 0 0 1Wrybill 45 26 73 61 105 105 128 214Turnstones 0 0 0 0 0 0 0 0Southernblack-backedgull NC 4019 4801 6469 7723 7723 N/C N/CSIPO 166 27 48 85 45 45 96 56Piedstilt 58 0 26 45 106 106 30 113Spur-wingedplover 52 22 343 1083 115 115 1620 547Blackshag 8 17 4 2 4 4 3 0Littleshag 0 0 0 1 1 1 2 0piedshag 0 0 7 0 0 0 0 0Paradiseshelduck 8 0 19 31 45 45 28 12BlackSwan 0 0 0 0 106 106 0 0Greyduck 0 0 0 0 549 549 0 0Mallard 0 0 0 0 0 0 0 0NZshoveler 0 0 0 0 13 13 0 0Duckspecies 111 157 85 111 106 106 37 60Canadagoose 170 13 537 426 549 549 301 221Kingfisher 0 1 0 1 0 0 1 1Welcomeswallow 0 10 0 4 13 13 15 0White-facedheron 12 0 11 10 3 3 24 12Feralpigeon 0 7 0 0 0 0 46 30Pipit 0 9 0 5 2 2 11 0Harrier 0 2 1 1 1 1 21 7
Table3:Adultbirdcountsby1kmunitsduringthe2018WaimakaririMidRiverSurvey.(N/S=Notsurveyedduetopoorweatherconditionsforcingsurveyorsofftheriver).
KMUNIT Wrybill BandedDotterel
Black-frontedTern
Black-billedgull
Southernblack-backedgull
SIPO Piedstilt White-frontedtern
White-facedheron
Blackshag Piedshag Black-fronteddotterel
CaspianTern
White-wingedblacktern
1 0 6 0 0 3 2 0 0 0 0 0 0 0 0
2 1 10 9 1 1 0 0 0 0 0 0 0 0 0
3 14 18 6 0 16 0 3 0 0 0 0 0 0 0
4 10 13 8 2 0 0 0 0 0 0 0 0 0 0
5 8 16 0 0 1 0 0 0 0 0 0 0 0 0
6 N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S
7 N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S
8 N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S
9 N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S
10 N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S
11 N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S
12 N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S
13 N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S
14 N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S
15 N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S N/S
16 1 5 2 0 34 0 0 0 0 0 0 0 0 0
17 2 6 0 0 630 2 7 0 0 0 0 0 0 0
18 8 24 7 0 4 0 9 0 0 0 0 0 3 0
19 14 20 58 0 2 1 9 0 0 0 0 0 0 0
20 4 5 3 0 0 2 0 0 0 0 0 0 0 0
21 7 15 40 0 705 3 0 0 0 0 0 0 0 0
22 3 10 0 0 200 2 1 0 0 0 0 0 0 0
23 0 14 2 75 49 2 3 0 0 0 0 0 0 0
24 4 13 4 550 276 1 12 0 0 0 0 0 0 0
25 7 7 5 0 2 2 5 2 0 0 0 0 0 0
26 8 18 14 0 0 0 0 0 0 0 0 0 0 0
27 10 13 3 3 10 0 2 0 0 0 0 0 0 0
28 4 9 0 0 0 2 1 0 0 0 0 0 0 0
Table3continued.
KMUNIT Wrybill BandedDotterel
Black-frontedTern
Black-billedgull
Southernblack-backedgull
SIPO Piedstilt White-frontedtern
White-facedheron
Blackshag Piedshag Black-fronteddotterel
CaspianTern
White-wingedblacktern
29 7 1 1 0 6 0 0 0 0 0 0 0 0 0
30 10 4 2 0 103 0 0 0 0 0 0 0 0 2
31 11 26 3 52 0 2 0 2 0 0 0 0 0 0
32 13 14 2 2 0 0 0 0 0 0 0 0 0 0
33 6 2 2 0 5 5 0 0 0 0 0 0 0 0
34 2 4 2 0 400 0 1 0 0 0 0 0 0 0
35 9 9 5 0 2000 7 0 1 0 0 0 0 0 0
36 7 7 2 0 0 4 6 0 0 0 0 0 0 0
37 2 22 242 200 2 6 19 3 8 0 0 0 0 2
38 11 21 102 1 0 4 10 41 1 0 0 0 0 0
39 15 21 40 0 2 5 8 0 1 0 0 1 0 1
40 11 27 23 0 0 2 9 3 2 0 0 0 0 1
41 5 8 15 0 1 2 8 1 0 0 0 0 0 0
42 5 13 5 18 37 0 7 0 0 0 0 0 0 0
43 4 18 7 0 155 1 7 0 2 0 0 0 0 0
44 9 11 30 0 0 2 13 0 0 0 0 0 0 0
45 4 5 11 1 20 4 6 0 4 0 0 0 0 0
46 1 9 84 2000 10 0 5 60 0 0 0 0 0 0
47 3 10 8 0 0 2 4 0 1 0 0 0 0 0
48 1 6 1 0 0 3 2 0 0 0 0 0 0 0
49 6 7 9 0 0 0 0 0 0 0 0 0 0 0
50 3 9 6 0 2 1 6 0 0 0 0 0 0 0
51 2 9 0 2 0 1 3 0 0 1 0 0 0 0
52 0 7 0 0 0 0 0 0 0 0 1 0 0 0
53 0 2 0 0 0 0 0 0 0 0 0 0 0 0
GrandTotal 252 494 763 2907 4676 70 166 113 19 1 1 1 3 6
