Nesting habitat of the little tern and fairy tern at Lake Tyers, Victoria

2013·2.8 MB·English

Research Reports
Nesting habitat ofthe Little Tern and FairyTern
at Lake Tyers, Victoria
M Kohout, H ZimmerandVTurner
ArthurRylahInstitute,DepartmentofEnvironmentandPrimaryIndustries,
123BrownSt,Heidelberg,Victoria,3084
Abstract
Thisstudygatherskeybaselinedataonthevegetationofterncolonysites atLakeTyers andestablishesper-
manentplots for future monitoring. We characterised thevegetation, substrate type, soil moisture, pH and
nutrientlevelsofLittleTernSternulaalbifronsandFairyTernS.nereiscolonysitesatthreeislandsinLakeTyers
estuary, Victoria. Monitoring plotswereestablishedattwocolonysites andfournon-colonysites, including
oneabandonedcolonysite. Vegetation coverwasestimated using thepoint quadrat method. Wefoundthat
ternsnestedinareaswith84%±1.89vegetationcover,potentiallymuchhigherthanreportedinpreviousstud-
ies;however, conclusions should bemade withcaution given thelowreplication inourstudy. Therewasno
significantdifferenceinvegetationattributesbetweencolonyandnon-colonysites.Along-termstudyinclud-
ingothercolonyareasalongtheVictoriancoastlinewouldbevaluableinunderstandingcolonyrequirements
ofthesethreatenedspecies.Thisisespeciallyimportantinthecontextoftheclimatechange-inducedimpacts
predictedtoaffectcoastalenvironmentsinthefuture.(TheVictorianNaturalist130(5)2013,192-201).
Keywords:soilnitrate,vegetationheight,seabirds, coastalsaltmarsh
Introduction
In Victoria, the Little Tern Sternula albifrons thoughtthat Little Terns avoid nesting in areas
and Fairy Tern S. nereis are both listed under with more than 20% vegetation cover, prefer-
the Flora and Fauna Guarantee Act 1988 as ringtonestinsparseorscatteredvegetation,al-
threatened,andareclassifiedasVulnerableand though this hypothesis has notbeen rigorously
Endangered,respectively(Reside2003;Depart- tested (Hill 1991; Owen 1991). Colony sites
ment ofSustainability and Environment 2007, are createdand modifiedbystorms,vegetation
2009). The Fairy Tern is also listed under the encroachment and human activity. The nests
Environment Protection and Biodiversity Con- of Little and Fairy Terns are typical of those
servationAct1999asVulnerable.TheVictorian constructed by the Sternidae family, a shallow
distributionofthesetwospeciesofternextends scrape in the sand, and are often lined with
along the eastern coastline from Mallacoota smallshells, shellfragmentsandsmallpiecesof
to Western Port Bay. In East Gippsland, Little vegetationwhenavailable(Reside2003).
and Fairy Terns are most commonly recorded ColonysitesintheGippslandLakesareahave
nestingtogetheronislandsinestuariesandoc- become increasingly important in the main-
casionally on ocean beaches from Mallacoota tenance ofLittle Tern and Fairy Tern popula-
to the Gippsland Lakes, though theyhave also tions in south-eastern Australia (Reside 2003).
been recorded in farwestern Victoria (M We- Recent studies, undertaken in the Gippsland
ston pers. comm.). For the past five years, the Lakesarea,suggestLittleTernbreedingsuccess
main colony (i.e. breeding) sites used by Lit- is affected by fluctuations in their food source
tle Terns have been in Gippsland: Mallacoota (Taylorand Roe 2004). Whysomecolonysites
(37o33'0" S, 149°45'0" E), Mario (37°46,60" S, havebeenabandonedremainsunknown.
148°3T59"E),TernIsland(37°51'5"S, 148°5'29” Raven and Plate Islands are the preferred
E), Crescent Island (37057'4"S, 147°45'31" E) breedingareasintheLakeTyersestuaryandap-
andCornerInlet (37045'57M S, 146o20'23" E) (F proximately 25 pairs ofterns bred at the Lake
M
Bedfordand Bramwellpers.comm.). Tyersestuaryinthe2009/2010breedingseason
Little Terns nest in colonies and nests are (FBedfordpers.obs.).Thetwospeciestypically
typicallyless than 1.5 m above mean high wa- nest togetheratthis location,astheydidinthe
ter (MHW) (Hill 1991). Substrates are usually 2009/2010 breeding season. These islands are
sandy and the vegetation low and sparse. It is well vegetated and are periodically inundated.
192 TheVictorianNaturalist
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Considerablevariation inplantheightandden- herbland to shrubland to rushland and sedge-
sityoccurs on the islands, with onlysmall sec- land (Daviesetal. 2003). CoastalSaltmarshcan
tionsusedbytheternsforbreeding.Thenearby comprise several zones. The lowest and most
andlargerTernIsland,alsowellvegetated,isel- frequently inundated zones are dominated by
evated higher above sea level and is inundated Beaded Glasswort Sarcocornia quinqueflora.
onlywhen moderate to severe floods or storm The next most landward zone consists ofherbs
surgesoccur. such as: Salt-grass Distichlis distichophylla,
Long-term drought in East Gippsland and Creeping Brookweed Samolus repens Shiny
,
artificial opening ofthe Lake Tyersestuaryen- Swamp-mat Selliera radicans Rounded Noon-
,
trance have caused water levels in the Gipps- flower Disphyma crassifolium subsp. clavella-
land Lakes to decrease over the past five years tum and Southern Sea-heath Frankeniapauci-
(F Bedford pers. obs.). This has led to concern florasubsp.pauciflora. SeaRushJuncuskraussii
over potential changes to the Little and Fairy subsp. australiensisandChaffySaw-sedge Gah-
Tern colony sites in Lake Tyers estuary, forex- nia filum may dominate the most landward
ample,whetherthedecreaseinwaterlevelmay zone (Daviesetal. 2003).
impact vegetation on the islands and whether
Sampledesign
this change would be favourable for nesting or
not. Land managers are particularly interested In February2010, paired smites (colonyand non-
colony),approximately80 apart,weresurveyed
in maintaining Little and Fairy Tern colony
on each ofPlate and Raven Islands. The colony
sites and, to achieve this aim, colony site char-
sites have been monitored since 1999 and were
acteristicsshouldbequantified.
Ourstudycharacterisesthephysical andveg- daensdigbnraotkeednuesgignsghevlilsu(aFlBceudesfosrudchpearss.necsotmsmc.r)a.peAs
etativeattributesofthecolonysitesofLittleand
FairyTernsatLakeTyers.Specifically,thisstudy single abandoned colonysite and a non-colony
gathers key baseline data on the vegetation of sitewere also surveyed on Tern Island. The flo-
tern colony sites at Lake Tyers and establishes risticsurveyoccurredlessthan30daysafterthe
Tern breeding season had finished (F Bedford
permanentplotsforfuturemonitoring.
pers. comm.) and no active nests were present.
m m
Methods Ateachcolonysite,a6 x 30 quadratrepre-
Studysite sentativeofthevegetationwaspositionedparal-
MHW
The study area was in the Gippsland Lakes in leltoandjustabovethe (Fig.2).Quadrats
the Lake Tyers estuary, East Gippsland, Victo- in non-colonysites wereplaced randomly, after
ria (Fig. 1). The two active colony sites are on stratification according to island, and distance
RavenandPlateIslands.RavenIslandcovers3.5 fromhigh-tidemark.
m
haand thecolony site area isapproximately50 Within the quadrat, three 30 transect lines
m m
x 10 in size. Plate Islandcovers 1 ha,with wereestablishedparalleltotheshoreline.Toen-
the colony site area covering approximately able re-location ofthe sites, pins and tags were
m
60 x20m. Ravenand PlateIslandsaresouth placed at both ends of transects (Fig. 2). The
ofan abandoned (inactive) colonysite onTern location (easting and northing) ofboth ends of
Island. Tern Island is larger in size (10 ha) and thecentre transectwere recorded. Photographs
slightly more elevated. The abandoned colony were taken atthe fourcorners ofthe site, look-
site examined in this study is situated on the ingtowardsthecentreofthequadrat.
south-easterntipofTernIsland,whereacolony Vegetation cover was estimated for species
zone (50 m x 50 m) was created from dredge in the whole quadrat using a modified Braun
spoil in 1999 (F Bedfordpers.comm.). Blanquet technique (Mueller-Dombois and
Vegetation ofthe islands consists of Coastal Ellenberg 1974) (Table 1). All plant species
Saltmarsh. This Ecological Vegetation Class is were identified according to Walsh and Stajsic
restricted to coastal flats subject to the influ- (2007).
ence ofdaily inundation and exposure to salt Fine-scale measurements ofplantspecies and
water and poor drainage (Davies et al. 2003). substrate (sand, muddysand,litter,attachedlit-
Coastal Saltmarsh ranges from a low succulent ter,driftwood,shell) coverwere recorded using
Vol 130 (5) 2013 193
Research Reports
Fig. 1. LocationofstudysiteatLakeTyersandthelocationof: 1.TernIslandshowingthepalecolouredaban-
donedcolonysite,2.RavenIslandand3.PlateIsland.
194 TheVictorianNaturalist
Research Reports
*- Photopoint
^
PinandTag
shoreline
4
TransectA
TransectB
i
^1 TransectC
30m
Fig.2. Schematicdiagramofsamplingareaateachsite.
m
the point quadrat method (Godinez-Alvarez et ple comprised a core, 0.05 diameter and 0.1
al. 2009) withsamplingat20cmintervalsalong m depth, incorporating minimal surface litter
eachofthethree 30mtransects (125points per and avoiding guano. The samples were pooled
transect). This method involves recording the andasub-samplewasbagged (300-500 g/sam-
different plant speciesorsubstrate that touches ple) and subsequentlyanalysed fortexture and
a steel pin at given intervals, and since more available phosphorous, total phosphorous, ni-
thanonespeciescantouchthepinateachpoint trate, ammonium, total nitrogen, potassium,
this can result in a cover abundance ofgreater sulphur, organic carbon, total carbon, con-
than 100%overall.Thismethodisobjectiveand ductivity, pH (CaCl2), pH (H?0) and chloride.
repeatable compared to visual estimates com- AnalyseswereundertakenbyCSBPLaboratory
monlyusedtoestimatecoverabundanceofveg- (Western Australia). Volumetric soil moisture
etation.Furthermore,theprecisionofcoveresti- (expressed as a percentage) was measured
matesusingthepointquadratmethodishigher within each quadrat, using a theta probe type
than for visual estimates (Godinez-Alvarez et ML2x (Delta-T Devices, Cambridge, UK) to a
al. 2009). Vegetation height also was measured depthof80mm.
at20cm intervals alongthethreetransect lines
DataAnalysis
using a rising plate meter (Michell 1982). The
Plantspeciesdatawerecategorisedaccordingto
distance from the edge ofthe vegetation to the
high-tide mark was measured every 1 m along origin, life cycle, and life form. Frequentist sta-
tistical analyses were not performed as the po-
thetransectclosesttothewater.
Three soil samples were taken randomly tential for significant results was low, given the
within each quadrat using an auger. Eachsam- lowreplication.
Vol 130 (5) 2013 195
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Table1.ModifiedBraun-Blanquetcover/abundancescale.
Category Characters
+ sparselyorverysparselypresent;coververysmall(<5%)
1 plentifulbutofsmallcover(<5%)
2 verynumerous,orcoveringatleast5%ofthequadratarea
3 anynumberofindividualscovering25-50%ofthearea
4 anynumberofindividualscovering50-75%ofthearea
5 coveringmorethan75%ofthearea
A principal coordinates analysis (PCO) using There was no clear grouping of colony and
the Bray-Curtis dissimilarity index was used non-colonysitesaccordingtoplantspeciesand
to identify differences between the colony and substrate cover in the PCO (Fig. 4). The first
non-colonysitesonthebasisof(1)plantspecies dimensionwassignificantlyandpositivelycor-
and substrate cover and (2) soil characteristics related with Rough Blown-grass Lachnagrostis
(Legendre and Legendre 1998). PCO was per- scabra (Spearmans correlation; p = 0.83, P =
formedusingtheveganpackagein R(Oksanen 0.04). Australian Salt-grass Distichlis disticho-
et al. 2011) on data that had been square root phylla (p = 0.89, P = 0.03) and Knobby Club-
transformedand standardisedusingWisconsin sedge Ficinia nodosa (p = 0.84, P = 0.04) were
double transformation (Bray and Curtis 1957; significantlycorrelatedwiththeseconddimen-
Oksanenetal.2011).PCOwasundertakeninR sion. Fifty-nine per cent of the variation be-
(RDevelopmentCoreTeam2011).Correlations tween the sites was described by the first and
between dimensions and individual variables seconddimensionofthePCO.
were examined using Spearmans rank correla-
tioninR(RDevelopmentCoreTeam2011). Soilattributes
Colonysites had highernitrates andsoil mois-
Results ture than non-colony sites (Table 3). In terms
Vegetationcoverandcomposition ofsoil textural attributes, the colony sites had
The Little and Fairy Tern colony, non-colony a higher amount ofshell grit than non-colony
sites and the abandoned colonysite were vege- sites (1% ± 0 and 0.2% ± 0 respectively). The
tatedbycoastalsaltmarsh.Bothcolonyandnon- abandoned colony site was characterised by
colonysites were dominatedbytypical compo- 74% cover ofshellgrit andhadlesslitter, more
nentsofcoastal,succulentsaltmarshvegetation, baregroundandlowersoilmoisturethancolo-
namely Creeping Brookweed Samolus repens. nyornon-colonysites (Table3).
Narrow-leafWilsonia Wilsonia backhousei and Eighty-six per cent ofthe variation between
BeadedGlasswortSarcorniaquinqueflora. sites, in terms ofsoil attributes, was described
The abandoned colony site differed from the by the first dimension of the PCO (Fig. 5).
othersitesinbothvegetationandenvironmental Variation along this dimension was most sig-
variables.Theabandonedcolonyhadthehighest nificantly negatively correlated with moisture,
cover value ofannual species, the lowest cover potassium, conductivity, chloride (p = -1.00, P
ofperennial species, native tufted graminoids, =0.003) andclay(p= -0.99,P=0.0003).There
shrubs and succulents (Table 2). Mean vegeta- was no clear grouping ofcolony and non-col-
tion heightwaslowestatthe abandoned colony ony sites according to soil attributes, although
sitecomparedtothecolonyandnon-colonysites theabandonedsitewasweaklyseparatedonthe
(Table2).Thevegetationcoveroftheabandoned firstdimension.
colonysitewaslower(12.8%±0.86) thanforthe
Discussion
colonyandnon-colonysites(Fig.3).
Both colonyand non-colonysites had a rela- Vegetationattributesofcolonysites
tively high vegetation cover. The overall mean AtLakeTyers,LittleTernandFairyTerncolony
vegetation cover ofcolony sites was 84.53% ± sites appeartobecharacterisedbyavegetation
1.89,whilstthatofnon-colonysiteswas96.66% cover of82-85%; however, it should be noted
± 35.32 (Fig. 3). that this is a general observation since there
196 TheVictorianNaturalist
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Table2.Summaryofsitevegetationattributes. Datapresentedaremeans±standarddeviation forthecolony
andnon-colonysiteandrawvaluesfortheoneabandonedcolonysite.
Vegetationattribute Colony Non-colony Abandoned
(n-2) (n=3) (»=1)
Speciesrichness
Numberofplantspecies 14± 1 17±4 13
Speciesorigin
%exotic 4±5 7±6 23
%native 96±5 93±6 77
Specieslifecycles
%annual 22± 1 23±6 38
%perennial 74±4 71 ±4 54
Lifeforms
%exoticherb 4±5 7±6 15
%nativeherb 55±2 59±7 46
%nativerhizomatousgraminoid 11 ±5 9±8 15
%nativetuftedgraminoid 15± 1 13±4 8
%shrub 15± 1 13±4 8
%succulents 56±0 46±20 1
Vegetationheight
Meanheight(cm) 5± 1 4±2 0.55
160
1 2 3 4 5 6
Site
Fig. 3. Vegetation cover (%) across sites. Data are from the point quadrat method and are presented as the
mean+standarddeviation.
Vol 130 (5) 2013 197
Research Reports
0.15
°i
0.05
4
0
-0.3 -0.2 -0.1 0 0.1 0.2
-0.05
-0.1
-0.15 nesting
non-nesting
-0.2
abandoned
-0.25
Fig.4. Principalcoordinatesanalysisplotofmeancoverofvegetationandsubstrate attheterncolony, non-
colonyandtheabandonedterncolonysiteatLakeTyers.
0.4
0.1
0
-0.3 £W.2 -0.1 0 0.1 0.2 0.3 0.4 0.5
-0.1
-0.2
-0.3
nesting
-0.4
non-nesting
Aabandoned
-0.5
Fig. 5. Principal coordinates analysis plot ofsoil attributes at tern colony, non-colony and the abandoned
colonysiteatLakeTyers.
198 TheVictorianNaturalist
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Table 3. Summaryofsite soil attributes. Data presented are means ± standard deviation for the colonyand
non-colonysite and rawvalues for the one abandoned colony site. Substrate covers were derived from the
pointquadratmethod.
Site Colony Non-colony Abandoned
(n=2) (n=3) (n=1)
Physicalattributes
Meansoilmoisture(%) 21 ±7 17±24 1
Chemicalattributes
AmmoniumNitrogen(mg/Kg) 7±3 4± 1 <1
NitrateNitrogen(mg/Kg) 6± 1 3± 1 1
PhosphorusColwell(mg/Kg) 6±3 3±2 8
PotassiumColwell(mg/Kg) 141 ± 101 258±355 24
Sulphur(mg/Kg) 195±89 456±700 7
Organiccarbon(%) 0.3±0 1 ± 1 0.1
Conductivity(dS/m) 2± 1 3.8±5 0.1
pH(CaCl,) 7±0 7± 1 8
pH(H,0) 8±0 8± 1 9
Chloride(mg/Kg) 1389±871 4361 ±6608 21
Texturalattributes
Clay(%) 5±2 8.1 ±8 3
Coarsesand(%) 91 ±4 84± 16 94
Finesand(%) 3± 1 3.2±2 2
Sand(%)
(sumoffineandcoarse) 94±3 87± 14 96
Silt(%) 1 ± 1 4.6±5 1
Substratecover
Litter(%) 35±2 41 ±8 0.3
Shellgrit(%) 1 ±0 0.2±0 74
Bareground(%) 4±4 21 ±35 74
wasalowreplicationofsites.Nevertheless, this ducing the risk offlooding and accessibility to
finding is incontrast to previous studieswhere terrestrial predators (Fasolaand Bogliani 1984).
terns were found to nest in areas where the These needs are often in conflict, since elevated
vegetation cover was less than 20% (Hill 1991; nestsites are more protectedfrom flooding, but
Owen 1991; Department ofSustainability and safetyfrompredatorsrequiressitestobeatlower
Environment 2009), and two explanations are elevations sincetheyare lessvisible (Fasola and
possible. It maybe that thevegetation cover in Bogliani 1984). RedFoxessometimespreyupon
previous studies has been underestimated. Al- eggs and young and have caused the abandon-
ternatively, the terns at Lake Tyers are nesting ment ofentire FairyTern colonies (Department
insuboptimalhabitat. of Sustainability and Environment 2009). Rec-
Little and Fairy Terns may choose areas of reational use ofsandy spits and beaches by hu-
higher percentage vegetation cover as protec- mans, or even the usage ofmotorboats nearby,
tion,orperceivedprotection.TheislandsinLake can result in thedisturbanceofbirds fromtheir
Tyers estuary are frequented by domestic dogs nests, resulting in chilling or heat stress ofeggs
Canis lupusfamiliaris. Red Foxes Vulpes vulpes, and small chicks; trampling ofeggs and chicks
Silver Gulls Chroicocephalus novaehollandiae may also occur (Carney and Sydeman 1999;
,
Pacific Gulls Larus pacificus and Ravens Cor- Dowling and Weston 1999; Weston and Elgar
vusspp. (F Bedfordpers. comm). Aswithother 2005). Such recreational use is common on
beach-nestingbirds,disturbancebypredatorsor southern Australian coastlines (Maguire et al.
humans is likely to influence nesting success of 2011).
terns (Dowling and Weston 1999; Weston and Lessthan20%vegetationcoverpreviouslyhas
Elgar 2005). Colony site selection by the Com- beenreportedasbeingimportantinterncolony
mon Tern Sterna hirundo is associated with re- site selection (Hill 1991; Owen 1991). Manage-
Vol 130 (5) 2013 199
Research Reports
mentofterncolonysitesinVictoriahas,insome ous studies report that seabirds can affect the
instances, involved vegetation removal such as vegetation ofcolony sites over time via nutri-
at Werribee (P Menkhorstpers. comm.), Rigby entinputs, andphysical disturbancetosoiland
and Crescent islands (Reside 2003) and the plants (Gilham 1959; Vidal et al. 2000; Garcia
Bairnsdalearea(Hill 1991;Owen 1991).Asthis et al 2002). Nitrate and phosphate in seabird
baselinestudysuggeststhatternsmaybeableto guano can result in changes to competitive in-
nest in areas with vegetation cover higher than teractions between plant species (Vidal et al
previouslythought (82-85% cf. <20%), we sug- 2000; Garcia etal 2002). In particular, vegeta-
gest that anyvegetation removal at tern colony tionmaymovefrombeingdominatedbynative
sitesshouldbeconsideredcarefully. perennial species, to exoticannual species (Vi-
Apotentialexplanationforthedisparityines- dal etal 2000). Garcia etal (2002) found that
timates ofvegetation cover at tern colony sites theabundanceoftwochenopodshrubswasin-
issurveymethod.Hill(1991) andOwen (1991) fluenced by the amount ofgull guano present.
used ocular estimates for vegetation cover. Theabundance ofSuaeda verawas found tobe
Whencompared,ocularestimatesofvegetation higher in guano-rich sites, while Salsola op-
cover are typically lower than objective meth- positifolia was the dominant species in areas
odssuchaspointquadrats(Godinez-Alvarezet least affected byseabirds on Mediterranean is-
al. 2009). Using ocular estimates for this study lands(Garciaetal 2002). fairyandLittleTerns
we would have reported estimated vegetation spend only a few weeks each year breeding at
covers of 40-60%. However, in this study we the LakeTyersestuary islands (f Bedford pers.
used the more accurate and repeatable point comm) and their effect on the vegetation may
quadratmethodforcollectingcoverabundance be relatively minor. A longer-term study is re-
data, leading to higher covervalues (Godinez- quiredtodetermineifthevegetationofthetern
Alvarezetal 2009). colonysites is changing, and ifthis change can
Saltmarsh vegetation is zoned according to be attributed to the terns and their associated
elevation and inundation, resulting in a strong nutrientinputs.
gradient in vegetation composition and height
with distance from the high-tide mark (Bert- Characteristicsofahuman-made, abandoned
ness and Ellison 1987). Little Tern colony sites colonysite
tendtobelessthan 1.5 mabovehightidemark The creation ofartificial colonysites is consid-
(Hill 1991).Samplesitesinthisstudy, incolony ered a potential conservation action for Little
andnon-colonyareas,wereselectedcontrolling Terns (Hill 1991; Owen 1991). At Lake Tyers,
for distance from the high-tide mark. Hence, the man-made, now abandoned colony site
weweresearchingfordifferences between sites hadvegetationandsoilconditionsthatdiffered
thatwerevisually/superficiallyverysimilar. An from the colony (and non-colony sites); it had
important limitation of this study is the low the lowest vegetation cover, the lowest relative
number ofsites surveyed: six sites only, with a cover ofnative tufted graminoids, shrubs and
maximum replication ofthree, and these were succulents, andthevegetation was, on average,
not independent. Low replication is often a shorterthan atactive colonysites. Moreover, it
problem in studies of threatened species (see hadless litter, more bare groundandlowersoil
Weston and Elgar 2005); however, this study moisture than colony or non-colony sites. In
does provide valuable preliminary data on the the first years after it was created, the artificial
characteristics oftern colonysites, and a more site had more vegetation cover and probably
extensive surveyofthe Lake Tyers islands, and greater soil moisture than atthetimeofsurvey
ofcolonyand non-colonyareas along the Vic- (L Bedford pers. comm.). The reasonsforthese
changesareunknown.Intermsofmanagement,
torian coast, could provide greater insight into
when creating artificialcolonysites,vegetation
ternnestsitepreferences.
and soil attributes should be as similar as pos-
Soilattributesofcolonysites sibleto siteswhere terns do nest. Although the
Tern colonysitesintheLakeTyersestuaryhad physical attributes ofa site are ofimportance
higher nitrates than non-colony sites. Previ- in selection ofcolony site, social factors, such
700 ThpVirtnrinn 'Matnrali.et
.
Research Reports
asthetendencyforbirds to return to the same Fasola M and Bogliani G(1984) Habitatselection anddis-
colonysite,andsocialinteractions,arealsoim- tRriivbeurti(Iotnaloy)f.nCeosltoinnigalCWoamtemrobinrdasn7d,L1i2t7tl-e13T3e.rnsonthePo
portant(Gochfeld 1983). Garcia LV, Maranon T, Ojeda F, Clemente Land Redondo
This studyprovides keybaseline data for the R (2002) Seagull influence on soil properties, chenopod
shrub distribution, and leafnutrient status in semi-arid
futuremonitoringofterncolonyhabitatatLake Mediterraneanislands.Oikos98,75-86.
Tyers. The methods used in this study were GiilnhNaomrtMhEern(1N95e9w)ZVeeageltaantdiownitohfatecronmpaanrdatgiavnenneottecoolnonitehse
chosenbecausetheyarerepeatable,and,hence, colonies in Bass Strait, Tasmania. Transactions and Pro-
cinagn. bWeeurseedcoimnmaenfudtutrheatpraolgornagmero-ftemromnisttourd-y GopcchehyefsdeiilncdgaslMoatfttr(hi1eb9uR8to3ey)saolCfoSsolictoeinse.ytyCosoilftoeNniesaewlleZWceatatileornabnibdry8d8sL,6e,2a1s2t10-5T2-e32r41n.3s.:
oftern colonies be undertaken, encompassing Godinez-AlvarezH,HerrickJE,MattocksM,ToledoDand
moresitesfromtheVictoriancoastline. Under- VinagnmZeetehoJd(s2:00T9h)eiCrormeplaatriivesoutniloitfytfhorreeecvoelgoegtiactailoansmsoensistmoern-t
standingthecolonyhabitatofthese threatened andmonitoring.EcologicalIndicators9,1001-1008.
birds is critically important given the changes HilTlerRn(i1n9A9u1s)trAalisat.raAtuesgtyrafloiranthNeatcioonnsaelrvPaatrikosnaonfdthWeilLdiltitflee
predictedto affect ourcoastlines, due to future Service,Canberra.
climatechange. LegendrePandLegendreL(1998)NumericalEcology.2edn.
(Elsevier:NewYork)
Acknowledgements MaguireGS,MillerKK,WestonMAandYoungK(2011)Be-
Theauthorswish to thankMick Bramwell and Faye iconagstbaelsidreestihdeentsesasoidfe:sobuetahc-heaussteeranndAupsrterafleirae.nceOsceaamnon&g
Bedford for providing detailed background infor- CoastalManagement54,781-788.
mation on Little and Fairy Tern colony ecology at Michell P (1982) Valueofa rising-plate meter forestimat-
Lake Tyers. In addition, Faye Bedford assisted with ingherbagemassofgrazedperennialryegrass-whiteclover
fDniiaeevsl.iddwWoCerhketbahylasnfhkoroSwatisensvigestuSasinncscieltaewisri,tcuhDrarpelvnaitndtlyCiudaesmnetedirfaoiscnactoialonond-, Musoewdlaslreodrfs.-VDeGogrmeatbsaostiiasonnDdEFcaoonrldaoggEyel.lSec(niTbehenercgeBl3H7a,c(k18b91u7-4r8)n7.APiremsss:anNdeMwetJehr--
aClnadirPeetMeorxShmaimt,hsDfaonrnaydvRicoegeorsn astnadtisMtiickaleaWnaelsytsiosn. OksOse’ayH)naernaJ,RBB,laSncihmeptsoFnG,GKLi,ndStolRy,mLoesgeP,ndSrteevPe,nMsiMncHhiHnaPnRd,
helped improve earlier versions ofthis paper with Wagner H (2011) vegan: Community Ecology Package.
constructive comments. This work was funded by http://CRAN.R-project.org/package=vegan. Accessed 20
DepartmentofEnvironmentandPrimaryIndustries February2012.
(formerly Department of Sustainability and Envi- Owen R(1991)A report onthemanagementoflittleterns
wroonrmkenwta)s,caSrtraiteedwioduetuSenrdveircerse,seEaarscthGpieprpmsiltanndu.mbTehre (a1Sn9td8e9rE/nn9av0iarblobrniefmeredonintns,g) Bisaneiarstnohsned.alBeaD,ierpVniascrdttoarmlieean.RtegoifonCondsuerrivnagtitohne
10005735. RDevelopmentCoreTeam(2011)R:Alanguageandenvi-
ronmentforstatistical computing. RFoundationforSta-
References tisticalComputing,Vienna,Austria.http://www.R-project.
BertnessMDandEllisonAM (1987) Determinantsofpat- org/.Accessed10January2012.
terninaNewEnglandsaltmarshplantcommunity.Eco- ResideJ (2003) LittleTernSterna albifronssinensis.Action
logicalMonographs57,129-147. Statement.No.51.DepartmentofSustainabilityandEnvi-
BrayJRandCurtisJT (1957) Anordination ofuplandfor- ronment,Melbourne.
estcommunitiesofsouthernWisconsin.EcologicalMono- TaylorIRandRoeEL(2004)Feedingecologyoflittleterns
graphs27,325-349. Sterna albifrons sinensis in south-eastern Australia and
CarneyKMandSydemanWJ(1999)Areviewofhumandis- theeffectsofpilchardmassmortalityonbreedingsuccess
turbanceeffectsonnestingcolonialwaterbirds.Waterbirds: andpopulation size. MarineandFreshwaterResearch 55,
DaTvhieesInJtBe,rnOaattieosnaAlJMourannadlTorfWuamtbeurlbli-rWdaBridolAogVy2(22,00638)-7E9c.o- Vi7da9l9-E8,08M.edail F,TatoniTand Bonnet V(2000) Seabirds
logicalVegetationClassMappingat1:25,000inGippsland. driveplantspeciesturnoveronsmallMediterraneanislands
rDaelpgaonr.tmentofNatural ResourcesandEnvironment,Tra- WaaltsthheNeGxpeannsdeoSftanjasticiveVta(x2a0.0O7e)coAlogcieans1u2s2,of42t7h-e43v4a.scular
DepartmentofSustainabilityandEnvironment (2007) Ad- plains of Victoria. (Royal Botanic Gardens Melbourne:
vDiespoarrytmLiesnttooffTShursteaaitneanbeilditVyeartnedbrEantveirFoanumneanti,nEVaiscttoMreila-. WeMsetlobnouMrnAe)and Elgar MA (2005) Disturbance to brood-
bourne. rearing Hooded Plover Thinornis rubricollis: responses
Department ofSustainabilityand Environment (2009) Lit- and consequences. Bird Conservation International 15,
tleTernSternaalbifronssinensis.ActionStatement.No.51 193-209.
EastMelbourne.
Dowling B and Weston MA (1999) Managing a breeding
population ofthe Hooded Plover Thinornis rubricollis in
a high-use recreational environment. Bird Conservation
International9,255-270. Received28June2012;accepted16May2013
Vol 130 (5) 2013 201