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NaturalistNotes Some observations ofHumped spiders (Uloboridae) at Notting Hill, Victoria Introduction In October 2011, two small spiders built ad- the abdomen triangular in profile, while the joiningwebsundertheeaves andpatio roofon males were smaller andyellowish brown, with the south side ofour house in the Melbourne a distinct white central stripe along the up- suburb ofNotting Hill. ByNovember2012 the persurface ofthe cephalothorax (Fig. 1). Both webhad become alarge, rambling, bluish tint- sexesspentmuch ofthetimelookingmorelike ed, messy-looking structure that measured ap- debris than spiders (Figs. 2 and 3). Behaviour- proximately1900x900x600mm.Mostpeople wise,theyweresomewhatsimilartoPhiloponel- would have swept itawayrightat thestart, but la congregabilis as described in Clyne (1969, as I decided toleave italone andseewhatI could Uloborus congregabilis). However, according to find outaboutitsoccupants. arachnologist Robert Whyte (pers. comm. 13 CharacteristicsofHumpedspiders October 2012), determination to species may The web was home to Humped spiders, which be difficult as this is an understudied group; belongtothefamilyUloboridae (MuseumVic- also, he had not seen a white stripe on a male toriapers.comm. 5 January2012),andarealso uloboridbefore. known as ‘feather-legged spiders’ or ‘hackled The two adult females that were present in iolryb,wHeuavmeprse’d. sLpiikdeerosthhearvemneombveernsomofgltahnidss,fabmu-t w20e1e1k eoafchJapnruoadruyce2d01a2ntehgegrecawsee.reInabtohuetfir3s4t black spiderlings in the web. They seemed not isimlmk.obTihleiysebutihledirspormeeywbhyatwraaspypmimnegtriitcianl,spuisdue-r to move about much, and I didn’t see them catch or eatanyprey, although theymust have ally horizontal or sloping, semi-permanent wheel webs, which often form a mass oftan- doneso. Sincenothingseemedtochangeasthe gledsilksharedbynumerousindividualspiders weekspassed, Imadethemistakeofnotpaying attention. (Simon-Brunet 1994). Unlikeotherspidersthat build wheel webs, Humped spiders do not re- Suddenly, one day early in September 2012, monoeve(Mtaherpolledswe19b62w).heTnhetrheefyorceo,nswtrhuecnt amnaenwy aInndotwiecrede—tmhuatchthbeigygoeur.ngThsepriederwserheadalsmooufletweedr spiders keep making or repairing webs in one ofthem about 20. By this time a number of location,thetotalsizeofthewebkeepsincreas- insects were becoming caught in the web. The ing(pers.obs.).Thetextureofthesilkiswoolly, spiders bound some ofthem up in little white and is termed ‘cribellate’ (Simon-Brunet 1994; parcels (Fig. 4), but appeared to ignore others Main 1976). Several other spider families have altogether (Fig. 5). I saw one spider juggling wtuhleeobbsoorr(giCadhnsislafdroer1t9ph6re8o)od.nulcIyinnoAgnuescsrtirtbahelalitlaa,ptretohsdielurkce,ebauwrtehetsehilex uWtipwkotiopweh1d4ii0taemwpeoarfbcsespliitsde,e(rsFisogim.lke6t)uo.lboAibcnocdroiurdpdsitpnhigediertrospruetsyh!ee Theprocess cantake20minutesormore(Mar- genera ofuloborids, with 13 described species ples 1962). (Simon-Brunet 1994). Marples (1962) states thatseveral speciesintheUloboridaearesocial Matingbehaviour inhabitsandlivetogetherinlarge numbers. During September and October 2012 saw I HumpedspidersatNotting Hill some male spiders in the web, and happened fIedmoanl’etskwneorwewahbiocuhts5pmecmieslownags,idnartkhegrweeyb,.wTihteh taondwi2tnOecstsobmeart.inAgmtaakleepslpaicdeeronvis2i6teSdeaptfeemmbaelre Vol 130 (3) 2013 139 NaturalistNotes Fig.1.MaleHumpedspider,showingwhitestripeon cephalothorax. Fig.4.FemaleHumpedspiderbindingupprey. many times. He started by vibrating the web. Ifshe answered’ byvibratingtheweb, they ap- proachedeach other,comingtogetherbriefly. If sheignoredhim,hedidn’tadvancetowardsher, butwaitedalittlewhilebeforetryingagain. The femalespiderdidnotkillthemaleaftermating. Fig.3.MaleHumpedspiderlookinglikedebris. tiUmnefoerltaupnsaetdebleytIwceoeunldmnaottinasgcearntdaitnhheobwuimludicnhg ofeggcases. 140 TheVictorianNaturalist NaturalistNotes Fig.5.Flyinweb,ignoredbythespiders. Fig. 6. Female Humped spider with two parcels of prey. Eggcases Incubationtime Theeggcasesofthesespiders were lightbrown An eggcasethatwasconstructed on 1 Novem- and looked rather like a narrow dry Holly leaf ber hatched 57 days later, on 28 December, so mm mm (Fig. 7). Theywere 12-16 long and 5 Iexpected theeggcase constructedon 14Nov- across at the widest point. Fifteen egg cases ember to hatch on 11 January, but this didn’t were constructed during theperiod from early happen. On 4 January the temperature soared Septemberto 14November.Eightofthesewere to 41°C and, based on my previous observa- made between 29 September and 5 October, tionsofnewlyhatchedBlackHousespiderlings when two were built every second day. The dying in 40°C on 2 January 2012, I concluded spiders constructed their eggcases earlyin the that the heat probably killed the spiderlings. morning, possibly starting at first light. On 3 On 12 January, I opened the egg case, and October, I sawtwoputtingthefinishingtouch- found 42 dead spiderlings and eight dried up estotheircasesat6.30 amAEDT, andby7am eggs. If it was the heat that killed them, they they had completed the task. On 5 October, I checked the web at 4.30 am, while it was still dark, and nothing was happening, but at 5.30 am when I checked again, two females were making eggcases. Onehad finishedbyabout9 am,theotherby 10am. Once an egg case was completed, the female spider remained with it most ofthe time, up- side down, departing onlyoccasionallyto cap- ture prey. At one stage I saw two adult spiders holding prey while with their egg cases, but I don’t knowwhether or not theyhad left in or- der to secure the prey. One spider seemed to beabsentfromhereggcasefrom27November — untilshereturnedon7December.Most ifnot — all ofthespiderslefttheireggcasesfromtime to time. On 28 November none ofthe spiders was guarding the egg cases but most returned thenextday. Fig.7.FemaleHumpedspiderwitheggcase. Vol 130 (3) 2013 141 NaturalistNotes were hatching on 4 January, an incubation pe- to U. congregabilis (now P. congregabilis), says riodof51 days, soitseems that the incubation thattheyoungspiderssharethemotherspider’s timescanvary.Becauseoftheirpositionsinthe meals ‘until they are old enough to make tiny web,theseweretheonlyeggcases Icould keep websadjoininghers’. trackof. The other egg cases contained no un- During November, hundreds of spiderlings hatched eggs, just tiny white scraps ofbroken were scattered throughout the web, so there eggshells’. weretimeswhenaspiderlingwould encounter Numberofspiderlings anadultfemalethatwasnotitsmother.Onone The number of spiderlings emerging from occasionI sawanadult,whichhadnotyetpro- ducedaneggcase, send aspiderlingawaywith the egg cases varied considerably. The largest akickfromoneofherfeet. number I observed was about 73 (Fig. 8) and the smallest 16. Most egg cases produced at Unusualbehaviour least50spiderlings. By 11 December, there were still two egg cases that had not produced spiderlings, and as far Maternalbehaviour as I could tell only one adult spider remained. I was able to observe some ofthebehaviour of On 22 December this adult was with her egg a mother spider and her 16 spiderlings, which emerged on 2 November. After the spiderlings left the eggcase, the mother spiderbuiltaweb for them to venture into. The mother spider and spiderlings appeared to communicate by vibrating the web or by touching each other with theirfeet. The first prey item that I saw caught in this web (on4November) wasacranefly. Thespid- erlings converged on it and sucked it dry, with no obvious help from their mother, although she remainedcloseby (Fig. 9). Themotherdid notbindthisinsectinspidersilk.Laterthesame dayaflywascaughtinthewebandthemother bounditonlypartiallybeforethespiderlingsfed from it (Fig. 10). The next day the spiderlings fedfromanotherpartiallyboundinsect. On 14 Fig.9.SpiderlingsandCranefly. November I watchedaspiderling feedingfrom a fully bound insect. After a while the mother chased the spiderling away and took over the prey for herself. Clyne (1969, p.34), referring Fig.8.Spiderlingsnewlyemergedfromeggcase. Fig. 10.Spiderlingswithpartiallyboundfly. 142 TheVictorianNaturalist NaturalistNotes case, which she had constructed on 1 Novem- insect was too big for it to tackle. The insect ber; however, on the morning of23 December struggled untilitescaped. anadult—presumablythesameone—waswith To human eyes the spiders werevery untidy, mm the other egg case, which was about 200 not destroying old webs or getting rid ofthe from her own. She stayed with this egg case rubbishthataccumulatedinthem,suchastheir until 28 December, when about 50 spiderlings moulted exoskeletons, remains of prey, dead emerged from her own abandoned egg case. leaves,thistledown andalargeamountofdust. Alas, by this time she was in the clutches of Sometimes sectionsofthe web were torn away a Daddy Longlegs spider (Fig. 11), which fed bythewind, making room for newwebs to be from her for at least 25 hours. I had hoped to built.Threespidersbuiltwebsontheoutsideof seeifshewouldreturntoherowneggcaseonce the old one, expanding the total size consider- thespiderlingsappeared. ably. Part ofone web was attached to my idle spiderwebsweeper! Otherbehaviour Unless the web was touched, these spiders Predators showed no timidity when being observed by RedWattlebirdswereactivepredators, takinga humans. Generally, they seemed to be a bit total offive female spidersalongwith theiregg slow to act, except when capturing prey. They caseson8and9October.Spidersandeggcases werenotaggressive.Whenonecameincontact deepwithinthewebweresafefrombirdattack, with another’s egg case, the owner chased the probably because the birds didn’t want their intruder away,butthere wasnorapid response headscoveredin spidersilk. from either. After a few moments the intruder Daddy Longlegs spiders, five ofwhich lived droppeddownonastrandofsilkandremained closetotheFlumpedspiders’web,capturedsev- there for some time, as uloborids do when eral adults, aswell asothertypes ofspiders in- alarmed(Main 1976). cludinganotherDaddyLonglegs. Theyseemed A fly became caught in the web, but no spi- tobe able towalk in the Humped spiders’ web, der approached it. After struggling for a while thoughtheywereusuallyseenneartheperiph- theflyescaped. Therewere a fewinsects inthe ery. Theywere capturing adult spiders as early — — web that didn’t appear to have been taken by as ifnotbefore 20September. — the spiders atleasttheyhadn’t been wrapped Small black wasps appeared to prey on the up (e.g. Fig. 5). An insect became caught in a Humped spiders, and were seen buzzing spiderlings web. The spiderling investigated it aroundthewebonmanyoccasions.Sometimes but then turned away, presumablybecause the theybecameentangledbutasfarasIknowthey alwaysescaped. Because many of the female spiders were killed by predators, large numbers of newly hatched spiderlings were motherless. I could not tell whether or not they coped, because therewere so manyspiderlings intheweb that it wasn’t possible to keep track ofthem. They startedtodisappearinthefirstweekofDecem- ber,theirfateunknown. Otherspidersintheweb Two other spiders entered the web and made themselves at home in it. Both were small and thin-bodied. Theblackone (Fig. 12), which often rested in a stretched out’ position, looking like a motionless black line, arrived on 28 De- Fig. 11 DaddyLonglegsspiderfeedingfrom female cember.Thebrownonewiththepaleunderside Humpe.dspider. (Fig. 13) was first seen on 29 December. They Vol 130 (3) 2013 143 NaturalistNotes stayed until 19 January. Thebrown one caught a fly (Fig. 14), but apart from that I didn’t see eitherofthemeatanything. X\ Mothsonthewallbehindtheweb *— Iwassurprisedthatsomemothsspenttheday- time restingonthewallbehindtheweb. I don’t rv knowhowtheymanagedtogetinandoutwith- V outbecomingentangled,butno doubt theweb \ offeredthemprotectionfrompredators. / // ( Theoutcome Of the fifteen egg cases, five were eaten, one failed, and nine produced spiderlings. By the endofDecember2012 alltheadultspidershad Fig. 12.Blackspiderthatcameintotheweb. disappeared (as had the Daddy Longlegs) and, bytheendofJanuary2013,onlyfivespiderlings remained out of about 400 that had emerged from the egg cases. Life for Humped spiders is veryhazardousindeed! Acknowledgements Thankyou to Simon Hinkley, ofMuseum Vic- toria, and RobertWhyteforinformation about thespiders,andtoGaryPresland forobtaining someofthereferencematerial. References Child J (1968) Australian Spiders (Cheshire-Lansdowne: Melbourne) ClyneD(1969)AguidetoAustralianspiders:theircollection andidentification(Nelson:Melbourne). http://en.wikipedia.org/uloboridae viewed8October2012 MainBY(1976)Spiders(Collins:Sydney) MarplesBJ(1962)NotesonspidersofthefamilyUloboridae. Fig. 13. Brownandcream spiderthat cameinto the TheAnnalsofZoology4,1-11. web. SiAmuosnt-rBalriuannestpiBder(s1.99(4R)eeTd:heChsialtkesnwowoebd:NaSWna)turalhistoryof VirgilHubregtse 6SanikyStreet NottingHill,Victoria3168 Fig. 14.Brownandcreamspiderwithfly. 144 TheVictorianNaturalist