RADIO HARNESS SYSTEM FOR BOBCAT KITTENS

5 Pages·1991·2.2 MB·English

by  Boyde H Blackwell

GreatBasinNatmalist51(4), 1991,pp.343-347
RADIO HARNESS SYSTEM EOR BOBCATKITTENS
B( H. Hlackw( CraiitT. Krost ,J( T. Kliiulc HanvA. Barlx-i
—
Abstract. Eiglitbobcatkittt-nswerefittedwitha.speciallydesignedharnesssystemsupportingaradiotransriiitter.
Thesekittensweretheyoungestknown toberadio-instrumented. Thissystemwasusedsuccessfullythroughtwo
seasons,fromJune 1989toJanuary1991. Littersofkittenswerelocatedsoonafterbirthforweighing, marking,and
aging(b\-tootheruption). Duringthefirstyearwhenkittenswereatleasteightweeksoldandsixweeksoldthesecond
year,attemptsweremadetoradio-instrumentkittensineachlitter.Thisharnesssystemallowedlitterstobelocated
periodicallyuntiltheirdeathordispersal. Wewereabletocollectimportantdataduringthemostcrucialandleast
knownweeksoftheli\'esofbobcatkittens.
Keytcords: bobcat.Felisrufus,kitten,radiotclemetnj.behavior,mortality,break-awayharness,Utah.
Littleinformationhasbeengeneratedcon- would fit smallerand youngerkittens yetex-
cerning the first 48 weeks ofhfe for bobcat pand to fit juveniles. By modifying Jackson
kittens {Felis rufus). McCord and Cardoza etal.s(1988)design, wewereabletodevelop
(1982) andJackson (1986) reported thesefirst aharness successfully usedon bobcat kittens
weeksofhfewere crucialtofnrtherdevelop- asyoungassixweeksold.
mentofhuntingandpredator-avoidanceskills This study tested the hypotheses (1) that
that enable the dispersal of experienced an expandable, drop-off, radio-instrumented
bobcat kittens. Our study ofbobcats made it harnesscouldbe successfully usedon bobcat
itinocnreoafsipnrgelyy,clloecaartitohnatofhafbrietsahtwsaetleerc,tioann,dlsoucca-- ktihtethenasrnaesssyowuonugldasnesiitxhweereakltserolndoramnadl(b2e)htahva-t
cessful predator avoidance are all important iornorcontributesignificantlytomortality.
factors directly related to survival ofbobcat
kittens.
Radio-instrumentedcollarshavebeenused StudyArea
successfullytocollectdataonbobcatsinmany
areas(Bailey1974, Karpowitz1981, Lawhead TheSheeprockandTinticmountainsofthe
1984, Jackson 1986, Litvaitis et al. 1986). WasatchNationalForestandadjacentprivate
However, due to the rapid growth ofbobcat property, as well as lands administered by
kittensintheirfirstyear, thefixedcollarused the U.S. BureauofLand Management, were
for adult bobcats was not considered an op- established by the Utah Division ofWildlife
tion. Intraperitoneal-implanted transmitters Resources as a study area in 1987. Most of
werealsonotconsideredasafeoptionforkit- the area is closed to all harvest and pursuit
tens for fear that in recovering from surgery ofbobcats. Included are portions ofTooele
they would not be able to keep up with the andJuabcounties in northwestcentral Utah.
normal movements of the litter and might Sagebrush-desert shrub, pinion-juniper,
have difficulty competing for food. Jackson mountain brush, and montane mixed forest
etal. (1988) developed an expandable, drop- are the common vegetative zones (Johnson
offharness for bobcat kittens five months or 1989). Average annual precipitation ranges
older, whichheusedinColorado. between 15.2 and 25.1 cm, with amounts
Afterourfirstyearofstudyconcerningthe increasing with elevation. Elevations range
reproductive habits of female bobcats and from about 1600 m to 2827 m. These moun-
their young in Utah, we felt it necessary to tains are typical ofthe cold-desert portion of
develop a radio-instrumented harness that thenorthernGreatBasin.
DepartmentofBotanyandRangeSc sity,Provo,Utah84602.
343
344 GreatBasinNaturalist [Volume51
iCi
Back Strap
Neck Loop
j^-Chest Loop
Radio Transmitter
Perforations
Vinyl Coated.
'Elastic Fabric
Polyester
Chest loop
Fig. 1. Anexpandable, drop-off, radio-transmitterharnessconstructedforuseonkittensatleastsixweeksold.
(A)One-pieceharnesswithelasticfabricbeforeharnesswasassembled. (B)Attachmentofradiotransmittertoneck
loop. (C) Completed harness; neckand chest loops are 1.5cm wide and elasticfabric is encased in vinyl-coated
polyester(VCP).Neckloopexpandsfrom15.5to26cm,chestloopfrom24to54cm.Backstrap(3cmlongX2cmwide)
andcheststrap(6cmlongX 1.5cmwide)aremadeofVCP.AntennaisencasedbytwosandwichedlayersofVCP.
HarnessConstruction tionsareapproximately2mm x 1mm(10per
Neck and chest loops, constructed of 1 cm"). Neck and chest loops, as well as the
c1o.v3e-rcemd-wibdyeaelalsatyiecrfaobfricb,rowwenrevicnoymlp-lceotaetleyd bthaeckshsatrpaep,ofwaecraepictoalnsHtr(uFcitge.dlAi)n.one piece in
polyester (VCP) reinforced with imbedded TheVCPcheststrapwaspop-rivetedtothe
wovennylon string(Fig. lA). VCPisaperfo- chest loop and sewn to the neck loop with
rated fabric and allows sunlight to penetrate waxed upholstery cord. A small radio trans-
totherubberfabric, thusincreasingpotential mitter (Telonics Inc. Model 070, Mesa, Ari-
fortime-baseddisintegration. These pcrlora- zona) was stitched, with waxed upholstery
1991] lUnioHarnessSystemeohB()Bc;atKiitens 345
cord, toawiderpieceof VCPfabric inserted
at the bottom of the neck loop (Fig. IB).
The antenna for the tran.sniitter, encased in
theVCPharness, protrndedshghtlyfrom the
chestloopatthebottom(Fig. IC). Theedges
oftheVCPharnessweredonblestitchedwith
nylon thread. The completed width of the
chest and neck loops was 1.5 cm, the back
strap was 2 cm wide x 3 cm long, and the
cheststrapwas 1.5cmwide X 6cmlong.
The neck loop circumference was 15.5 cm
andexpanded to26cm, while thechest loop
was24cmandexpandedto54cm. Theaver-
age weight ofthe completed harness system
was 46.5 g, less than halfthe weight ofthe
harnessusedbyJacksonetal. (115g; 1988).
(Bj
Results
To place the harness on the bobcatkitten,
we stretched and pulled the neck and chest
loops over the bobcat's head. The neck loop
rests in front ofthe shoulders on the neck,
withthetransmitterunderthechin(Fig. 2A).
Thechestloopfitsbehindthefrontlegs, with
thelegsstraddlingthecheststrap(Fig. 2B).
We radio-instrumented eight bobcat kit-
tens(fourmales, fourfemales)(Table 1). One
malekittenharnessedatnineweeksworethe
harness system for 28 weeks, at which time
the harness was replacedwith aregularone-
piececollarwornbyotheradultbobcats. We
found the harness in very poorcondition, as
wehadexpected. Weestimatedthatthehar-
ness would have fallen offin approximately
three to four more weeks. There were no
abrasionsorsorescausedfromwearingit.
Theharnesseswerewornbythekittensfor
a varied number ofdays (Table 1), the least
beingtwo days, the most32weeks. One kit- Fig.2. (A)Sideviewofbobcatkittenwearingharness.
ten was able to free itselffrom the harness (B) Bottom viewofharnesswornbybobcatkittenwith
because elastic inside the VCPwas purpose- frontlegsoneithersideofcheststrap.
fullycutwhentheharnesswasfirstplacedon
thekitten. Onekittenapparentlyhookedthe area. Because ofthis, we added two break-
back strap on a branch ofaprostratejuniper awaywindows(Fig. IC)totheneckandchest
tree and in its struggle to free itselftwisted loops, factors that will greatly increase the
the harness tighter around the branch and probability that the harness will break away
itsneck. beforecausingabrasiveinjurytothekitten.
Steigers and Flinders (1980) developed a
Discussion break-away, expandable collarfor mule deer
fawns. We recommend this same type of
Onlyonekitten,whichworetheharnessfor break-away system forthe bobcat kitten har-
32weeks, was found to have harness-related ness to ensure a complete and timely loss
sorespresentontheneckandinthechestloop ofthe harness. Steigers and Flinders found
346 GreatBasinNaturalist [Volume51
Table1. Resultsofradio-instrumentedharnesssystemfittedtoei^htbobcatkittens, 1989-1990.
1991 RadioHahnkssSvsikmfokBobcatKrnKNS 347
KARHOwrUrtza,hJboTbca1t9s81w.itHhormefeerreanncgeestoahnodmmeovrcannigfeiistelseco-f McCoRDly,nxC..PMa.g,esAN7D28J-.7E66CianrJd.oAz.a.Ch1a9p82m.anBoabncdatG.anA.d
tionandpreybase. Unpubhshedthesis,Brigham Feldhamer,eds..WildmammalsofNorthAmer-
YoungUniversity,Provo,Utah.42pp. ica. Johns Hopkins University Press, Baltimore,
Lawhead.D N 1984. Bobcat{Lynxritftis)homerange, Maryland.
density and habitat preference in south-central Stkicers,W.D..andJ.T Flindkr.s 1980.Abreak-away
Arizona.SouthwestNaturahst29:105-113. expandiblecollarforcervids.JournalofMammal-
LiTVAiTisst,atJ.usA.,reJpoTr.tM:ajboobrc,aatndmoJ,vAe.mSehnetrsbuinrnreela1t9i8o6n.tAo ogy61:150-152.
snowshoeharedensity. Page375inS. D. Miller
andD. D. Everett,eds., ProceedingsofInterna- Received1 May1991
TtieoxnaaslASy&mp1oUsniiuvemr,si1t9y8,2,KinCgoslvlielglee.ofAgriculture, Accepted1August1991