.Corella, 2003, 27(3) i 61-67
FORAGINGBEHAVIOUR OF HOODEDROBTNS Melanodryas cucullata lN THE NORTHERNTABLELANDS OF NEW SOIJTI{'WALES
LULU FtTRlrand HUGH A FORD']
zoology. Universityof New England,Armidale New Southwates 2351 rPresertaddress: Dejanemcn Biologi, LabtekXl, ITB, Jalan Ganesha10. Bandung40132' Indonesia 2Towhom correspondenccshould b€ addressed
Received:12 July 2002
Hooded Robins toraged mainly by pouncing or gleaningon the g.ound for invertebrates,with an increase in gleaning in winter Lessjrequently tniry nawrcO for ilying insects and gleaned or snatched prey from bark, both ot.nich were more common in summer and autumn.Although branches were the most frequent perches trom which foragingwas initiated,Robins also foragedfrom tfunks, stumps and logs and an array ol artificialstructures perches wire- typically close to the ground, though hawking, gleaning and snatching were usually carried out ground- 3-B metres ab6rie tn6 ground.-more Foraging rates weie more rapid in winter, partly due to the increase in feeding,which emptoys rapid loragingtechniques, but also becausethe absoluteforaging rates while ground gteani;g and pouncing increased.The sexes did not differ in their foraging behaviollr and there were only minor Oittereniesamong study sites. Comparisonswith other studies revealedthat Hooded Robins lorage in a similar way to the EasternYel'ow Robin Eopsalfriaaustrails, though the latter occupies open forest rather than woodland. The smafler Scarlet Petrolcamufticolot, Fla.Ae P phoenicea and Red-cappedP goodenovii Bobins also forage in a similar way to Hooded Robins,especially in winter, when they lorage more on the ground.
INTRODUCTION (Fitri and Ford 1997). A number of specific questionswere asked: Ground-foraging insectivores have been identified as a group of birds that have declined in southernAustralia (i) Do the sexesdiffer in their foraging behaviour? (Recher and Lim 1990; Robinson l99l Lunney et al. (ii) Are there differences in foraging behaviour among 1997), for reasons that are not entirely clear. One sites? hypothesis for their decline is that habitat loss, (iii) fragmentationand degradationhave reducedthe availability Are there seasonalchanges in foraging behaviour? of their food. Zanette et al. (2000) provided some support METHODS for this hypothesis.They found a lower biomass of ground invertebratesin smaller than in larger remnantsof eucalypt Srrd) riler woodland. They also found that in small remnants incubating female Eastern Yellow Robins Eopsahria Foraging behaviour of Hooded Robins was studied in three areas of eucalypt woodland near Armidale from April l99l to April 1992. austraLis were fed Gan less frequently by their mates, and and Strathaven are 15 kilomeues and l0 kilometres easl of Armidale. nestlings received less food. It is important, therefore, to New South Wales and Torrybum is 45 kilometrcs west of Armidalc. collect detailed data on the feeding behaviour of declining They arc described in detail in Firri and Ford (1997). The former two woodlandbirds. sites represent small, apparenaly isolated populations, wheteas Hooded Robins are generally more widespread and common around Torrybum. Hooded Robins, although widespreadin Australia,are Dcnsities of Hooded Robins averaged about 0-06 birds per hectare.All experiencinglocai disappearancesand regional declines,to sites contain a mixture of grassy woodland (13 to 83 large trees/ha) and open areas with only scattered trees. the extent that there is now concern about Open forest occurs at their Strathaven(>100 uees/ha), bu! is generally not used by Hooded RobiDs conservationin southem Australia (Robinsonand Traill The woodland conr2ined patches of regrowth eucalypts and shrubs (4G- 1996;Fitri and Ford 1997;Reid 1999; camett and Crowley 890 shrubs,4ra),as did some of the treelessareas. Shubs werc less dense 2001). The specieshas been described as a ground feeder at Torrybum than at the other two sires. by Brooker et al. (199O) and Gilmore (1985), and Graham Reco rding fotagins behaioul ( 1990) suggestedthat it fed 70 per cenr on the ground and 30 per cent in the air. The only quantitative foraging data Foraging data were collected on 8-ll birds al Gara,4 birds al on the specieshave been collected for short periods in Strathaven and 9-10 birds at Torrybum in each season.Most individuals were not colour-banded, mulga near Alice Springs (Recherand Davis 1997), bur could be tenlarively id€ntified from their and trome ranges. Only one bout was recorded for in acacia and wandoo each individual on anv woodland in Westem Austrdlia day, bur severalwerc colleclrd io a season.The ser of eachindirrdujl (Recherand Davis 1998tRecher er al., in review).These was delermined by plurnage. Sub-adult rnales were distinauished from confirmed that Hooded Robins mostly pounce on the lem.lec because thc) hrve darker gr€y uppfrpan\ ;nd mo ted ground, but display a small amount of hawkins and utde$arts. Older males p.ogressively develop a ctear dark grey bib on the,upper breasr. L. Firri (LLF) fo owed individual snatchingor gleaningfrom foliageand bark. Hooded Robins for as IoDg as possible and timed and dicrated their activiries into a casserte re.order. For. each foraging move In this paper rle present data on the foraging.behaviour she recorded the foraging method. the subsrate on which foraging occurred, of the HoodedrRobin, alld the t)?e and heigh! of perch from an areain which it.is.declinins ,from,wfiich foraging was ifliriared. 62 L' Fit and H FordrForaging behaviour of Hoodod Robins in the northern tabletandsof New south wates cgrclla z7e) Foraging methods were: (Cooley and Lohnes l9?l). W})ere the MANOVA show€d a significanr (i) Pouncing- difference in foraging droppingor flyitrg to the groundto capturea food in relatioo ro one of the ,*f"ti* ""-',q-f.lijvl was cafiied item. out. B€cause more than one foraging bout was often recorded for an individual bird in the same season, there is a risk of (ii) Gleanitrg- hoppingon a substrare pseudoreplicaltotr. and rakingprey from il. Consequently. the more cooservarrvelevel of (iii) - slgtrllcanceot p < 0.001 was used, Hawking flying from a perchto caprurea flying iosecr. (iv) - Hovering rernainingsationary in flight while taking an insect trom a substrate. RESULTS (v) snatching-flying from a perch !o gab prey from a substrate A total of 345 hours of observations was made, on the way past. with approximately_equaltime being spentin each5ite and in Subslratesfor prey captureand perchingw€rel ro owtng blrds ol each sex (Table 11. There were no (i) significant differences Ground,inctuding smalt dead branches, srones and animaldung. between males and females in (ii) Stumps. foraging methodffd subsrrare.perch site and heighr or loragingrates (Table 2) and also no significant (iii) Logs,larger dead branches on ground_ sex b-ysire or sex by season interactions.Consequently, (iv) dati are Trunksof live or deadstanding trees. combined for both sexes. (v) Branches,twigs or foliageof standingrees. (vi) Foraging method and substrate Artificial objects- f€trceposls, sign posts,fence wire, electrical wires. The foraging method and substrate were combined into The a small number . heiBhlofrhe perchfrom wlxch foragisgwas initiared was placed of frequently used behaviours. Hooded rn rne tol|owl0B -categories:0_
TABLE 1 Numbers of hours of observation of each sex at each sile in each season; the figure rn parenthesesis lhe number of fomgitrg records at each site in each season,sexes cdmbined.
Gara Strathaven Torryburtr
19.2 20.66 16.'t9 18.18 18.4 13.3? (l 666) ( I 070) (r | 41) 8.l2 I1.4 11.55 14.9 15.87 t1.12 (1 896) (3014) (3 40',7' Spring 8.65 12.44 10.15 t3.26 12.76 13.95 (t 132) (851) (r 24O) Summer 16.73 14.1.1 t't.61 15.53 17.56 13.05 (788) (749) (83s)
TABLE 2 Results of MANOVA !€sts for differences in foraging method, perch substrate and height alld foraging rales between sexes,sites and seasoos,
Sex Site SeasoD ForagitrgMethod Fsr:= 0 55 F,a" = 1 73 Frs.ro= 5 06 P = 0.74 P = 008 p < 0.0001 PerchSite Fo.r= 0.11 F,'= 3.92 F,e,,,= 4.82 P=099 P = 0.0001 p < 0.0001 PerchHeight Ftq=012 Fr.u = 9.29 F:r.rrs= 6.37 P = 0.88 p < 0.0001 p < 0.0001 Foragingrate Fs.g= 1.00 F,ore= I 80 F:.,rr=460 P = 0.43 P=007 p < 0.0001 September,2OO3 L. Fit and H. Fofd. Foragingbehaviour of Hooded Robins in the northern lablelandsof New South Wales 120
100
80 o Snatch E') I (E wHawk tr 60 o mGl Bark o Gl Ground o o- 40 n Pounce
20
0 WSpSu Gara Strathaven Torryburn
FlglJtre l. Foruging method a d substrate of Hooded Robins at Garc, Sttuthawn and Torryburn in each season. A - autumn, W - h/intea Sp - spring, Su - swwner. GI - glcat
100
90
80 I Rrtificiat 70 E GroundObl o stump CD An 12 (E-- ffi Log o .rv Z rrunk o n Branch o-o4u 30 20 10 0 A W SPSU A W SPSU A W SPSU Gara Strathaven Torryburn
Fig'*e 2- The percenta{e of each perch Dpe used by Hooded Robins a! Gara, strathaven and rorrybum in each season. 64 L- Fiti and H Ford'Foraging;behaviour of,Hooded Robins in the northern tablelandsof New South wales Corolta27{3)
GARA STRATFIAVEN TORRYBURN AUTUMN >10 8-<10 5'<8 5.<8 3-<10 5-<8 3-<5 3-<5 3-<5 2' <3 2-<3 1-<2 0-<1 0-<1
WINTER
t.<10 8.<10 8-<10 5-<8 5-<8 5-<8 3.<5 3.<5 2.<3 2-<3 2-<1 't.<2 1-<2 1-<2 E 0-<1 0-<1
.? SPRING o T s-<10 8-<10 5,<8 5-<8 5-<8 3.<5 2-<3 2-<3 2.<3 1-<2 0- SUMMER >10 8-<10 8-<10 8.<10 5-<8 5-<8 5- Relative,Freq.usrrsy of Use (%) Fi9]dre3. Hzights of perchesfr 70 GARA STRATHAVEN TORRYBURN o 60 (, o 50 o) o --r- Pggr c 40 o E Glgr - --r-Glbk o 30 --o-HwHv (ro --.-Sn 20 '= (E t- o LL 0 Aut Win Spr Sum AutWin Spr Sum AutWin Spr Sum Fi,glJJe4. Foraging ftrte (attempts per hour) by Hooded Robinsfor eatlt main foraging mehod a! each site in each seann. Pggr = pouncing on grcund, GLgt = gleaning on ground, GLbk = Sleaning on bark, HtlHr' = hawking and lnve ng, Sn = snatching. The frequency of different foraging methods differed roraStnS rales significantly among seasons.Hawking and hovering were There were highly significant seasonal differences in more frequent in summer and autumn than in winter and foraging rates (foraging attempts per hour) but no spring at all sites (Fig. 1). Gleaningon the ground was significant differences among sites (Table 2). Hooded most frequent in winter in all sites and gleaning from bark Robins foraged higher rate in was most frequent in summer.Pouncing on the ground was at a winter than in the other (Fig.4). most frequent in spring, mainly due to its very high seasonsand Ieastrapidly in summer There are two gleaning frequency at Strathaven in this season. There were no components to these seasonaldifferences. First, interactionsbetween seasonand site. on bark, hawking and hovering, all of which were used most in summer and least in winter, were performed at low Perch sites rates compared with ground-feeding. Secondly, the main foraging behaviours,gleaning and pouncing on the ground, There were significant differences in perch sites among were performed at a greater rate in winter than in summer. study sites and among seasons(Table 2), as well as = interactionsbetween these two variables(F\w 2.77, DISCUSSION p = 0.0001). There were relatively minor seasonalchanges in perch site at Gara (Fig. 2). However, Hooded Robins at Hooded Robins are principally ground foragers,as found the other two sites showed a high use of branchesin in other habitats from more limited data (Brooker et al. summer and a correspondingly lower use of perchesclose 1990; Recher and Davis 1997,19981-Recher el cl., in to the ground, such as stumps,logs and objects on the review). We found that the species gleans as well as ground. There was a number of modest,though significant, pounceson the ground. We defined the method as gleaning differences among the sites. Hooded Robins used artificial when the bird showed any hopping along the ground, even perchesmore at Torryburn and stumps somewhat less. after flying down from a perch. In contrast, Recher (pers. comm.) included such behaviour as pouncing. Hooded Perch height Robins also display a small, though varying proportion of other foraging behaviours, such as gleaning from bark, There were significant differcnces in the heights of perches hawking, hovering and snatching (as found by Gilmore used for foraging among sites and seasons (Table 2). 1985and Graham 1990). Hooded Robins mostly perchedon or near the ground, with a secondarypeak at 3-5 metres or 5-8 metres above the We found no significant differences in the foraging ground in all seasonsexcept for winter (Fig. 3). The latter behaviour between male and female Hooded Robins, Other heights correspond to bark-gleaning and hawking. The studies on foraging behaviour of Australian robins have differencesamong sites were mainly due to differential use looked for sexual differences. Wheeler and Calver 0996) of the upper levels, with 3-5 metres being the favoured found that male and femaleRed-capped Robins were very secondaryheight at Tonyburn and 5-8 metres at the other similar in their foraging method and use of substrateson two Sltes. RottnestIsland, Westem Australia. Mac Nally (2000) found L Fiti and H Ford: Foragingbehaviour of Hooded Robins in the northern tabletandsof New south wales corella 27t31 no consistent differences in foraging behaviour between Australia (Wheeler and Calver 1996; Recher sexesin Rose et al.- in Robins (Petroica rosea). Recher and Holmes review) and Northern (Recher (2000) Tenitory and Davis I997). found that female Scarlet Robins fed more on the They were rnainly ground-feedersat this time, with some ground than males, which fed more on bark and bv hawking, but it is possible thar this speciestoo may forage hawking. Sexes of Flame Robins did not diff; more above the ground in the warmer months. significantly. The general lack of sexual differencesamong robins contrastswith Golden pachycephalapectoralis anZ Recher and Davis (1997) and Recher et al. (in rcview\ Rufous Wristlers P. ruJiventris, in which males foraged found a very high overlap in behaviour and substrate significantly higher than females (Bridges 19S0, 1992; B-ell between Red-cappedand Hooded Robins (78_g57o).They 1986; Recher and Holmes 2000, but see Mac Nallv 2b00). also noted that Red-cappedRobins tended to forage nearer Perhapsthe fact lhar so much foraging is on rhe ground to shrubsthan HoodedRobins did, which meansrhat shrub does not allow much opportunity for diffeiential encroachmentin drier woodlands may favour the former exploitation of sites by male and female Hooded Robins. species.Hooded Robins may also overlapclosely with Also, there may be subtle differences in food or the tvDe EasternYellow Robins.as well as Scarietand Flame of ground on which the sexesforage, which rr;"r" not Robins in winter. Rose Robins tend to occuDy wetter investigatedin this study. forests. though in winter they move inlo more oDen habitats.where Seasonalch-anges in foraging. as shown by Hooded theysometimes lorage on the ground19 our ^ of 39 - Kobrns.are a lealureof smallerspecies of robinsin south_ observations Ford, unpublished).Two other birds occupy easternAustralia. Scarlet Robins changefrom hawking, the same study sites as Hooded Robins and often lnteract snatching,and gleaning from bark in summer to moie aggressrvely with them: the Willy Waetail ground-foraging in autumn and winter at Wollomombi (20 Rhipidura leucophrys and lhe Jacky Winter Micieca km east of Gara - Huddy 1979) and in the southern fascinans (Fitri and Ford 1998). Wagtails also fed tablelands of New South Wales (Robinson 1992a). Flame predominantly from the ground, though most of their prey Robins show this change even more markedly, with are captured rn he air (62.5Vohawking, 22Voground glean - hawking being rhe mo5t frequentactiviry in sLmmer. or pounce Ford et al. 1986). Jacky Winters are also $hereas In wrnler lhey mostly glean on the ground more aerial foragers than Hooded Robins (15_55% (Robinso_nl992a,b). However, thiJ speciesis a riigrant hawkrng,29-649o ground pouncing from three sites - moving from woodland to more open habitat in the-non_ Reche. e/ a/., in review; 7 hawk, 6 snatcb leavesor bark. breeding season.Hooded Robinj do not migrate, but 2 pounceground nearArmidale - Ford, unpublished). expand their home ranges outside the breedingieason to The finding of Zanette et al. (2OOO) ground include open hrbiral with only scatteredtree; (Fitri and that invertebratesare scarcer in small woodland Ford 1997r.Use of more open habitaris possiblythe remnanis than in larger reasonfor an increaseduring winter of ground_gleining. ones, and that this may alter the breeding reratlveto ground-pouncing. behaviour of Eastem Yellow Robins, is relevant to thi HoodedRobin. Changes ro the quantiryand qualityof their An increasein feeding rate in winter was also shown bv habitatmay influenceboth breedingsuccess and adult Scarlet Robins and even more markedly in Flame Robini surviyal in Hooded Robins. Additional measuementsof the by Robinson(1992b). Flame Robins, like HoodedRobins. abundanceof invertebrateson the ground and in the air in also increaselhe amountof ground-feeding in winrer.Their various habitats, and under various types of management, maxlmum rate, ol up to 250 pecks per hour, is about 5 are required to indicato the extent to which availabilitv of tlmes greater than the maximum rate for Hooded Robins. food may limit lhe distriburionand abundanceof sround- This. is probably because they take smaller prey, mostly foraginginsectivorous bird species.With particular-respecr beetles and ants about 2.5 millimetres lone (Robinson to Hooded Robins, more information is required on diet 1992b).The dier of HoodedRobins was nor q-uanrifiedbut and alsoon the abundanceof favouredfood in woodedand ants. moths.carerpillars. cranefl ies. butterflies. grasshoppers more open habitat throughout the year. We tentatively and skinks were seen being eaten. suggestthat Hooded Robins may experiencerelative food Differences in foraging by Hooded Robins among sites shortage in winter. First, they are most dependent on were generallysmall and not very consistentrhrou-gh the ground invertebrates in winter, foraging less from other year. They could have resulted from differences in the substrates. Secondly, their foraging rates are highest in availability of perches,differences in where food was most winter, indicaring that their energy demands a.e greatest available, or to idiosyncrasiesof the individual Robins. then, or food items are small, or both. The influence of grazing, weed and exotic grass encroachment,removal of A number of other robin speciesmay occur in similar woody debris,disturbanca of litter and microclimateon habitat ro Hooded Robins. There is a general gradarion availability of ground invertebratesshould from mostly ground-foraging in the large be studied, Hojded and especially in winter. EasternYellow Robins ro mosrly hawking and snarching in thesmall Rose Robin tFleming 1980i Recher er al] Long-term monitoring of sites in which Hooded Robins 1985; Ford et al. 1986. Mac Nally 2000). As mentioned currently occur should record their survival as well as earlier, the intermediate-sized Scarlet and Flame Robin notrng changes in the abundance of other ecolosicallv switch between more hawking and above-ground feeding similar species. It is possible that competition witli other rn- summer to predominantly ground-feedingin wintei ground-foragingand aerial insecrivoris, due to habitat (Huddy 19791 Fleming 1980:Recher er cl. l9-851Ford er changes, has played a part in the decline of the Hooded al. 1990; Robinson 1992a).Data are only availableon Red- Robin in southern Austalia. This hypothesis is worthy of capped Robins for late autumn to spring, from Western further exDlotation. tablelandsof New south wales seotember, 2oo3 L. Fitriand H. Ford. Folaging behaviourol Hooded Robins in tho norihern 'social Huddy, L. (1979). behaviourand feeding ecology of Scarlet ACKNOWLEDGMENTS ' Roiius (Petroicamulticolor) B Sc. (Hons) thesis'Uoiversity of New We lhankthe Australian International Development Assistance Bur€au England,Armidale. for providinga scholarshipfor Lulu Lusianti Fitri and the University Lunney,D., Curtin, A. L., Fisher,D-' Ayers, D. aDd Dickman,C R of New Englandand WorldwideFuDd for Naturefor researchsupport (19d7)-Ecological att butesof the threatenedfauna of New South We are gmteful to StuartCaims for assistancewith statistics,to Harry Wales.Pac. Corr. BioI.3t 13-26 Recher, Stephen Debus, Liana Zanette ar,d Doug Robinson for Mac Nally, R. (2000).Co€xistence of a locally undiffer€ntiatedforaging comm€nlingon the manuscript,and to SteveAmbrose for his useful guildravian snalche$ in a southeastemAustralian forest. A,lJl Ecol commentson the lhesisfrom which this manuscriptis taken 25. 69-82. Recher,H. F and Davis, W E. (199?).Foraging ecology of a mulga REFERENCES bird communily.Wildl. Res.Ut 2144- Recher.H. F. andDavis, W E. (1998).The foragingprofile of a waDdoo of wintering Bell, H. L- (1986). Sexual differenccs in the behaviour woodlandavifauna in early spring.Arrt J. EcoI.2!. 514-527. whistlers Pachycephala pectoralir ^t wollomombi, N s.w. Colden Recher H. F. Davis, W. E. and Calv€r,M C Comparativeforaging Enu 86t 2 11. 'Some ecology of five species of grouddpouncirg bitds of western Bndges, L. (1980). aspectsof the behaviour and feeding ecology Australianwoodlands. In review. of the Rufous (Pachlcephah rufve tris) ^nd Colden (P pectorulis\ F. and Holmes,R. T. (2000).The foragirg ecologyof birds Whistler' B. Sc. (Hons.) thesis, University of New England, Amidale Recher.H. 'Breeding forestand woodlandbirds. l. Differencesbetween males Bridgcs, L. (1992). biology of Rufous Whistler (Pd./ryc€pftala of €ucalypt Emu 100: 205-215. rufiventns): mate choice and delayed plumage maturation' Ph. D. and females. Kavanagh,R thesis, University of New England, Armidale. Recher.H. F. Holmes,R. T., Schulz,M, Shields,J- and Brooker, M. C., Brailhwaite, R. w' and Estbergs,J A (1990) Foraging (1q85).Foraging pattems of breedingbirds in eucalyptforest and ecology of some insectivorous and nectarivorous species of birds in woodlandof southeasternAusEalia. Aust. J Ecol l0: 399-420 forests and woodlands of the wet-dry tropics of Australia. E/nll 90: Recher,H. F. and Lim, L. (1990). A review of currentideas of lhe 2t5,230. extitrctioo,conservation and managem€ntof Australia'sterrestrial 'Multivariate Cooley, W. W and Lohnes, P R- (1971). data analysis.' vert€bratefauna. Proc. Ecol. Soc.Aust. 16t 28'l-301. (Wiley, New York.) Reid, J. R. (1999).Thr€atened and decliningbirds in the New South Fitri, L. L. and Ford. H. A. (1997). Status. habitat preferencesand social Wales Sheep-wheat Belt: L Diagnosis, characteristics and organisatior of the Hooded Robin Melanodryas .ucullata in thc management.Report to NSw National Parksand wildlife Service Northern Tablelands of New South Wales. Arrr. Bitd Watcher l7l (CSIROWildlife and Ecology:Canbena.) 142-155. Robinson,D. (1991).Threalened birds of Victoria: their distributions. Fitri, L. L. and Ford, H. A. (1998). Aggression among Hooded Robins ecologyand future.Vic. NaL 108| 67-'77. Melanodryas .ucullnta And other bids. Corella 22t 24-28. 'A Robinson,D. (1992a).Habitat use and foragingbehaviour of the Scarlet Fleming, P (1980). comparative ecology of four sympatric robins.' Robin and the Flame Robin at a site of breeding-seasonsympatry. B. Sc. (Hons.) thesis, University of New England, Armidale. Wildl. Res.19 : 37'l-395. Ford, H. A., Noske, S. and Bridges,L. (1986). Foragingof birds in eucalypt Robinson,D. (f992b).why do FlameRobins Petrcica phoenicea woodland in north-eastem New Soulh Wales. Enu E6t 168_179. migrate?A comparisonbetween the social and feedilg ecologiesof Ford, H. A., Bell, H. L. and Huddy, L. (1990). Seasonalchanges in the Flame Robin and the ScarletRobin P. muLlicolor.Corclla 16l foraging behaviour of lhree passerines in Australian eucalyptus I-14. woodland. .tlrder Avidn Biol. l3t 245-253. 'The Garnett, S. T. and Crowley, G. M. (2001). Action Plan for Robinson,D. and Traill, B. (1996).Conserving woodland birds in the Australian Birds.' (Environmcnt Australia: Canb€na.) wheat and sheepbelts of southernAustralia. RAOU Conservation Gilrnorc, A. M. (1985). The influeDceof vegetationstructure on the density StatementNo 10. 'Birds of insectivorous birds. In of Eucalypt Forests and Woodlandsl Wheeler,A. G. and Calver,M. C. (1996).Resource partitioning in an fuology, Conservation,Management.' (Eds A. Keast, H. F Recher. H. island community of insectivorousbirds during winter. Ena 96: Ford and D. Saundcrs.)Pp. 21 3l (RAOU atrd Surrey Beatty & Sons: 23-31. Sydney.) Zanette,L., Doyle,P andTremonl, S. M. (2000).Food shortage in small Craham, w S. (1990). Habilat requiremenls of two pairs of Hooded fragments:evidence from an area-sensitivepasserine. Ecolog) 8ll Robins nerr Canberra _ a preliminary tepotl. Canberra Bird Notes 1654-r666. lst 22-2'7.