Capture and radio-transmitter attachment techniques for Roadrunners

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Capture and radio-transmitter attachment techniques for Roadrunners Powered By Docstoc
Captureand radio-transmitter
techniques Roadrunners
      L.        and
Sandra Vehrencamp Liza Halpenny

                      study behavior gets its feet caught trapto peckat It usually takes
      spart two-yearthe and walksandjumpson thein the, and eventual-
      breeding        of   on (Geococcyx ly
             physiology Roadrunners
californianus), varietyof techniques were employed        several minutesof active lungingat the bait before a
to capturethe birdsand to attachradiotransmitters.In      bird becomes    snared. Occasionallybirdswill work at a
this paper we describethesetechniques   and evaluate      trap for 15 minuteswithout being caught,then lose
their relative success. studywas conducted theat                                   •t
                                                          interestin it. It is esse•, '.•,monitorthe trap continu-
GampPendleton     Marine GorpsBaseReserve,about10                                                   it
                                                          ously.If the bird is not caughtsecurely, can work its
milesnorthof Oceanside, DiegoGounty,      Galifornia.     way out of the noose in a few seconds,and if it is
The Roadrunners thisareawere very shyandwary,                                it
                                                          securelycaught, can injure its legsif left in the trap
presumably totheoccasional                 of
                               appearance Marine          longerthan a few minutes.    The trap is light enoughto
troopsand heaw vehicles.The birds preferentially                                         by
                                                          be draggeda shortdistance the bird, but doesnot
nestedin the largestclumpsof pricklypear (Opuntia}        need to be staked.
cactus. Opuntiawas typicallylocatedin denseaggrega-
                                                          This trap is inexpensive easyto construct.    Many can
tions on south-facing slopes.Seven active nestswere
                                                          be set out simultaneously, onepersoncan monitor
found during one breedingseason systematically
searching  theseareas.
                                                          3 to 4 traps if they are carefullyplaced.However, the
                                                          trap has 2 major disadvantages. first is the low
                                                          encounter    rate of birds with traps, resultingin poor
                                                          efficiency trappingeffort.We spentapproximately       12
Traps                                                     man-hours    monitoring  trapsper captured  Roadrunner.
                                                          Secondly, trap selectively      caught smallmalesin our
Raptor trap                                               studyarea. None of thesebirds were seen again,and
                                                          the few that were radio-tracked    disappeared  from the
        is        version Bal-chatri
 Thistrap a modified ofthe       or                       studyarea within a few daysof capture.We surmised
live-baitedfootnoose            and Mueller, 1959}.
                     trap {Berger                         thatthese  were young              or
                                                                                  dispersing itinerantbirds,and
We usean 18"squarepieceof 1/2"mesh   hardware cloth                                           at
                                                          that their interestand persistence the trapsreflected
as a base and attacha 12"x 8"x 11/2"    cageof 1/4"       their inexperience,  unfamiliaritywith the area,andre-
hardwareclothto it. The finer meshof thebait cageis       duced  foraging  success.Known   breeding birds,especial-
          to         the
necessary prevent bait fromescaping to pre-and                                           the
                                                          ly females,activelyavoided trap or madea single
vent the Roadrunner  from injuringthebait.The trapis                                              on
                                                          lunge at the mouse,then continued their foraging
thenspray-painted flat blackto improve     visibilityof   route.Trapsplacednear nests      were never successful.
                of                {40
thebait. Nooses medium-gauge lb. test}monofila-
ment fishing line are tied to the top of the baseand
cage.Nooseloopsof 2"to 3" in diameterplacedabout          Treadle trap
3"apart work best.The trapsare relativelylight,and
severalcan be stacked           for           but
                       together transport, they                  employs
                                                          Thistrap                   spring-loaded
                                                                      a treadle-activated,
tend to becomeentangled.   White laboratorymice are       doorto captureforaging                 It
                                                                                    Roadrunners. consists anof
the mosteffectivetypeof bait; brownor blackmiceare        18"-high                    body       or
                                                                   band-shell-shaped of 1/4" 1/8"hardware
less conspicuous, wild mice are much less active, and                    to
                                                          clothattached a fiat 12" x 18"wooden       base(Fig.1).
                                       The micedid
lizardsare generallycrypticand inactive.                                              to
                                                          The fine meshis necessary preventthe captured      bird
notperishwhenleft in the trapswithoutfoodandwater         from injuringits bill. A smallmouse cageis attached  to
and in full sunlight the entire morning.
                   for                                    the insidebackwall of the shell.A rat trap is attached
                                                          to the baseto supplythe closing                 A
                                                                                             mechanism. wire
This trap is placed either alongtrails and roadsfre-              the
                                                          shaped sameas,but a bit largerthan,the mouth         of
quented by Roadrunnersor near nests. A bird that                                   to
                                                          the shell is connected the closing    springof the rat
encounters trap is usually attractedby the mouse,         trap.Restraining  "L's"are put on the rat trap springto

Page128                                   North American Bird Bander                                Vol. 6, No. 4
keepthewire framefrom closing   pastthemouthof the          Mist    net
shell. Heavy black nettingis sewn looselyto the wire
frame to complete door.A "T" of woodattached
                  the                              to               heavy 4"mesh net used
                                                             A standard gauge mist was to
the triggerof the rat trap forms a large treadle.The        net nestingRoadrunners.   The net was either mounted
wire that holds down the springand attaches theto           on poles in the standardmanner in the vicinity of
trigger mustbe reshaped sustain addedweightof
                         to       the                                     or
                                                            knownnests, gentlydrapedaroundthe cactus      clump
the treadle. The entire trap is spray-painted  black.                   a                         did
                                                            containing nest.(The latterprocedure not destroy
When the'trapis set,the wire hoopdoorlies flat on the       the net.) In generalthe net wasplacedon the downhill
groundand the treadle is elevatedinside the shell. A        side of the nest. The bird was then flushed off the nest
white laboratory mouseis used as bait.                      from the uphill side,whereuponit glided or ran into
                                                            the net. This methodsuccessfully capturedall birds at
This trap was placed alongRoadrunnerforagingtrails          active nests,and failed only at neststhat were later
where birds leavingtheir nestswere known to pass.                       to
                                                            discovered be abandoned.                       of
                                                                                        The disadvantages the
Birds attracted to the mouse hit the treadle at the first
                                                            method are: 1) the large amount of time involved in
lunge,therebyquicklysnapping doorshut.The trap                        for
                                                            searching nests,and 2) a high probabilitythat the
was developedtoward the end of our study and was            adults will abandon their nest as a result of the distur-
thereforeemployed    only a few times,but it successfully   bance.
capturedall birds that encountered It workedespe-
ciallywell onbreeding   females. The primarydisadvan-       Rock net
tagesare its large size and heavy weight, makingit
difficult to store and carry. Roadrunnershave been
knownto enterthe commercially       available,
                                                                trap designed birds habitually
                                                             This was     tocapture that
squirrel-sized  treadle traps, but we believe that the                             for         or
                                                            perchon rockoutcroppings displaying sunning. It
higherand shorterhome-made         trap with the flexible          of
                                                            consists a 3'-squarepiece of heavyblack netting,
door is more effective for tall birds.                      weighted on four corners, and covered with monofila-
                                                            mentnoosessimilarto thoseusedin the raptortrap.It
                                                            was drapedovera rockwhere a male wasseengiving
                                                                    calls severaltimes.His feet were caught
                                                            courtship                                     in
                                                            the noosesthe next time he returned to the rock, but he
                                                                   out       we
                                                            slipped before could      reachhim.Thistrapseems
                                                            to work aboutas well as the raptortraps,but sinceit
                                                            contains bait, it mustbe placedin a commonly  used

                                                            Foot noose on a stick

                                                                trap  ofamonofilament
                                                             This consists          attached
                                                                                 noose    to
                                                                               The noose opened placed
                                                            theendof a 6' stick.       is     and     in
                                                                               with the stickdirectedtowardsthe
                                                            a nestover the eggs,
                                                            outsideof the nest clump.After the bird has settled
                                                            ontothe nest,the stickis pulled by a hiddenperson,
                                                            closing noose    aroundthe incubating  bird'sfeet. A
                                                            similartrapis described Gartshore   (1978).
                                                            The noosestickwas successful one time we usedit,
                                                            but it causeda great deal of trauma to both the bird
                                                                                The bird dove into the surround-
                                                            and the investigator.
                                                            ing cactus became        there.The investiga-
                                                            tor was therefore forced to wade into the cactus as
                                                            well. The nestsitewas damaged, the extremedis-
                                                            turbance caused abandonment of the nest.

                                                            Summaryof trappingmethods

                                                            Forstudies   the     ofbreeding
                                                                            capture     Road-
                                                            runners,it is muchmore productive searchfor nests,
Figure1: A home-made                       a
                      treadletrap employing rat-                   the         of
                                                            observe movements thebreeders,      thentrapthe
         sizedsnaptrap for the closing                      birdsawayfromthenestin a treadletrapor footnoose

Oct.- Dec.                                  North       Bird
                                                 American Bander                                              129
                  trappingbirds directlyat the nest
trap. As discussed,                                                     the
                                                         were tiedaround radioafterthewax-sealing   step,
risks abandonment, randomlytrapping        foraging      and pottedin with the dental acrylicso that they
birdsand hopingto follow themto their nests radio-       emerged                of                 A
                                                                 fromthe4 corners theradiopackage. soft
       is          because thelargeproportion
tracking inefficient        of                 of        vinylpadwasgluedto thebackof theradioto prevent
non-breedingbirdscaptured.                                      of
                                                         chafing the skin.The radio restedon the bird'sback
                                                               the      tracts
                                                         between scapular                   pointing
                                                                             with the antenna
                                                         posteriorly. top straps  were placedover the bird's
Radio-trackingand attachmenttechniques                             and
                                                         shoulders the bottomstraps      went aroundthe rib
                                                         cageunder the wings.Severalmethods tyingthe
Types of radios                                          strapsover the chestwere attempted     with varying
                                                         success.Following Dunstan(1972)  and Godfrey(1970)
 Three    of            wereused
      types radio-transmitters onthe                     we tied the 2 shoulderstrapsstraight       the
                                                                                             across upper
Roadrunners: a standardexternally mountedradio
              1)                                         chestand the 2 underwing strapsstraight       the
                                                                                                across rib
for monitoring           and
               movements home ranges, an ex-2}           cage,with a shortperpendicular  piececonnecting  the
ternally,mountedradio with an internally implanted       strapsat the midline. A secondmethodwas to criss-
thermistor                  bothmovements in-
          lead for monitoring                 and        crossthe shoulder and under-wing   strapsto form an
ternal body temperature,and 3] an internally implant-    "x" on the chest.With both of these methods,the birds
ed thermistor radio. All transmitters were constructed   managedto get their lower mandiblepermanently
following the designof Bradbury et al [1979).Each        caughtunder the straps,and thesemethodsare there-
radiooperated a uniquecrystal-controlled
              at                         frequency                        not             The
                                                         fore emphatically recommended. onlysuccess-
in the 148mHz range.Several modifications
                                        were intro-      ful harnesstechnique was a "back-pack"   design,in
duced. A 100 K ohm thermistor in series with a 150 K     which only the under-wingstraps               the
                                                                                        were tied across
ohm resistorreplaced the 220 K ohm resistorin all                                                 to
                                                         chest.The shoulderstrapswere connected the un-
temperature-sensitiveunits. Miniature crystalsavail-
able from Sentry Manufacturing Co., Chickasha,Okla-
homa, and miniaturetransistors(Siemens BFS20] were
substituted the implantedradiosto reducetheir size.
Receivers from AVM Co., Dublin, CA, with hand-held
Yagi antennas, were used to follow the radio-instru-
mented    birds.

All externallymountedradiospossessed whip an-
tenna, and were sealedin wax and pottedwith dental
acrylic; finished weight ranged from 10 to 15 gm,
depending the sizeof the batteryand the amount   of
potting. Implanted radios had no antenna, and were
dipped in a special wax available from Mini-Mitter,
Indianapolis,Indiana; finishedweight was between 1
and 2 •,,rn(dimensions mm by 15 mm]. The pulse
                                    units decreased
interval of the temperature-sensitive
with increasing temperature. The interval was mon-
itored with either a homemade  pulsetimer that direct-
ed continuous  outputinto a Rustrakstrip chartrecord-
er, or a commercially availablepulse timer from AVM
which had no provisionfor automaticrecording.   Tem-
perature-sensitive radios were calibrated in a slowly
coolingwater bath between 30øC and 45øC using a
Schulteisfast-readingthermometer.A final check on
the thermistor'saccuracy was made after implantation
by comparing radio readingto the measured     cloacal
temperature thebird.
Methods    of attachment
                                                         Figure 2. Ventralview of the "backpack"-style
           mounted were
All externally               tothe
                radios harnessed                                                               for
                                                                   •ng techniquerecommended all long-
birds with 1/4"cottontwill. Two long lengthsof twill              billed birds.

Page130                                   North AmericanBird Bander                              Vol. 6, No. 4
der-wing strapon the samesideof the body(Fig2). The         Discussion
shoulderstrapswere cut to the correctlengthand
loopedat the end in advance,so that the under-wing                 sectionattempt
                                                             •n this    we             the     ofthe
                                                                               toevaluate effects
strapscould be pulled throughthese loops and then           varioustrapping            procedures the behav-
                                                                            and tracking           on
             The final positionof the shoulderstraps
tied together.                                              ior of the Roadrunners.Roadrunners appearto be very
               be          to        by
couldtherefore adjusted comfort the bird. This              sensitiveto such disturbanceand many nestswere
methodof attachment   was very quick and avoidedthe         abandoned.   We thereforehope that future studentsof
problemof stuckbills.                                       Roadrunner                           can
                                                                         behaviorand physiology avoid many
                                                            of the mistakes we made.
The externally mounted thermistorradio was harness-
ed to the bird in the manner    described   above. The
thermistorlead extendedabout5 cm beyondthe radio                                           in
                                                            A totalof 22birdswere caught trapsplacedin forag-
packageand was encased silasticsurgical
                        in               tubingand          ingareas.              werefemales of these
                                                                       Five of these             (4        clearly
sealedat the tip with medicalsilasticcement.A small         in breedingcondition)    and 17 were males (breeding
incision was made in the skin on the back under the         condition  uncertain,but only 5 were within weight
radio package. standard
                A          laparotomy incision(Risser,      rangeof known breedingmales).Of 20 birds released
1971)was then made on the left side under the last rib.     in the study area, 9 were banded only, and '11were
A wire with a loop on the end was passed    from this       bandedand outfitted   with radiotransmitters.Only I of
second  incisionunder the skin up towardsthe first in-      the banded and releasedbirds was ever seenagain,
cision,and the thermistor lead was loopedthroughthe         and all of the radio-equipped birdsdisappeared  within
hook and pulled under the skin. The thermistor    was       2-14days.Thus we were not able to detectany notice-
directed into the peritoneum,suturedin place to a rib,                       in
                                                            able difference behavior      betweenradio-equipped
and the laparotomyincisionsuturedshut.A local anes-         and non-radio-equipped    birds. Further, birds which
thetic (Xylocaine ointment) and Neosporin antibiotic        received thermistorradios requiring surgerydid not
ointmentwere spreadon all incisionpoints.                                           rate
                                                            differ in disappearance from birdsreceiving      stan-
                                                            dardexternal          We
                                                                          radios. therefore           that
                                                                                               suspect thehigh
To insert the internally mounted radio into the peri-                       rate
                                                            disappearance of thesebirds is due to a highly
toneum, standard  laparotomytechniques were employ-         mobilenon-breeding    population ratherthanto the dis-
ed (Risser,1971).The incisionwas only slightlylarger                  of
                                                            turbance captureand tracking.
than that needed to view the gonads. The small wax-
embeddedradio was coatedwith Neosporinantibiotic            Nine additional birdswere captured  followingdiscov-
ointmentand gentlypushedinto the peritoneum.   The          ery of their nests.Sevenwere caughtwith mist netsor
musclelayer and skin layer were suturedseparately.          traps in the immediate vicinity of their nests and 2
No anesthetic               the
             was necessary, entire procedurewas                          in
                                                            were caught trapsplacedalong    predetermined  travel
very quick,and the birdsdid not appearstressed.             routeswell away from their nests.Four of thesebirds
                                                            remained               despite
                                                                    with theirnests,              type2 or 3
                                                            thermistor radios, and 5 abandoned their nests but re-
Comparison internal and external thermistors
                                                                  on              following
                                                            mained theirterritories                    im-
                                                            plants or standard radios. Thus some birds did not
          mounted    radios the
 Theexternally thermistor had im-                           abandoneven thoughthey were capturedon the nest
portant advantages long-range                     (1
                                    transmission km)
due to the presenceof the whip antenna, and long                        surgery,
                                                            and underwent      whereasotherscapturedon
radio life (3-6months/due to the larger batterymount-       the nest but not unnecessarilyhandled did abandon.
ed to the back.However,the surgery     was very difficult   The male and female of a matedpair abandoned    their
to performin the field, and the apparatus undoubted-
                                           is               firstnestfollowingcapturein a mistnet at the nest,but
ly moreuncomfortable the bird. More importantly,
                          for                               did not abandontheir secondnestfollowingcapture
                                                            well away from the nest.We therefore concludethat it
the externally mounted thermistorsdid not give accu-
rate readings body temperature.      This appearedto be     is capture                   disturbs breeding
                                                                      near thenestthatmost      the
due to the fact that the radiobodywasitselfsomewhat                      and              or
                                                            Roadrunners, notthesurgical radio-trackingpro-
temperature   sensitive,         a
                         causing shift in the calibration
curve when the radio was placed on the bird's body.                      mostof the problems trapping
                                                            Havingovercome                 of        and
The miniaturized,   implantablethermistors   were there-             Roadrunners, havebeenable to quanti-
                                                            monitoring         we
fore developed alleviatethis problem.         While they    fy the relative parental efforts of male and female
did give accuratereadings body temperature,          they   breeders and to obtain diurnal/noctural measurements
had the distinct disadvantages short transmission                                        bodytemperatures.
                                                            of male,female,and non-breeder
range (25-50m/ due to the lack of an antenna,and short                                                in
                                                            Thesedata are reportedelsewhere(Vehrencamp,
life/1-2 weeks)dueto thenecessarily                         press). In general, we have found the Roadrunner to

Oct.- Dec.                                      American Bander
                                            North      Bird                                                  131
                and         subject a stud•; much shortertransmitting
be a verydifficult inefficient   for                                                  or
                                                                    range.The presence ab-
involving            of          nesting
         manipulation free-ranging      birds.                 of
                                                          sence surgical            did
                                                                         manipulation not appearto affect
                                                                       of            by
                                                          theprobability abandonment thebird. •
                                                          Literature    cited
      of    on behaviorbreeding
 Aspart astudythe   and     phys-                         Berger, D.D. and H.C. Mueller. 1959. The Balchatri: a
iology of Roadrunners,a variety of capture and radio
                                                            trap for the birds of prey.Bird Banding30:18-26.
transmitter attachment techniqueswere devised and         Bradbury, J.B., Morrison, D., and Stashko, E. 1979.
tested.Capture procedures    included: a modifiedBal-       Radio-tracking  methodsfor bats.Bat ResearchNews
chatrifootnoose  trap, a home-made   treadletrap,a mist      20:9:17.
net, an unbaitedfootnoose  trap for rockperches, and a
                                                          Dunstan,         Radio-tagging
                                                                  T.C. 1972.                      and
                                                                                       falconiform strigi-
footnoose a stick.Severaltypesof radio-transmitters         form birds.RaptorResearch6(3):93-102.
and attachment  procedures  were alsoused:an extern-
                                                          Gartshore,         A
                                                                    M.E. 1978. noose                nesting
                                                                                    trap for catching
ally-harnessed thermistor radio with temperature-sensi-      birds. North American Bird Bander 3:102.
tive leads implantedin the body cavity,and an inter-      Godfrey, G.A. 1970. A transmitter harness for small
nally implantedthermistor   radio. The relative success      birds. IBBA News 42:3-.•
of these methods and their effects on the birds are
                                                                A.     A         for        laparotomy
                                                          Risser, '1971. technique performing
evaluated.Captureof breedingbirds couldbe guaran-            on small birds. Condor 73:376-379.
teed only by firstlocatinga nest,but capturetechniques
                                                          Vehrencamp,                    of
                                                                     $.L. Bodytemperatures breedingmale
involvingthe nestoften caused  abandonment.   Only one
                                                            versus                 (Condor, press].
                                                                  female Roadrunners       in
harnessing technique for externally mounted radio
transmittersproved successful.    Internally implanted    Departmentof Biology, C-016,Universityof California
thermistorradiosgavemore accurate     body temperature    (San Diego),LaJolla,CA 92093.
readingsthan externallymountedthermistors had a

Bird Banding in Alberta. Martin K. McNicholl (Edi-        hearted contribution   on the trials and tribulations   of a
tor]. 1981.The Alberta Naturalist,SpecialIssueNo. 2,      bander'swife are similarly ageless and do not reflect
73 pp. Available from: Federationof Alberta Natural-      that they were written decadesago.
ists, Box 1472, Edmonton,Alberta T5J 2N5, Canada.
$3.50 Canadian.                                           The recent studiesaddressan array of topics;papers
                                                          by M. McNicholland R. Fyfe and U. Banasch      provide
A compendiumof 13 contributions      dealing with bird    overviewsof banding and raptor banding in Alberta
bandingin Alberta and producedto commemorate        the   while other authors provide new data on the local
meetingof the American Ornithologists'    Union in Ed-                of
                                                          movements color-marked        gulls, chickadeepopula-
monton,thisissuewas designed provide an historical        tions, and sex determinationof dippers to mention a
perspective the currentactivebandingprogramin                                 of
                                                          few. No discussion banding in Alberta would be
thisprovince.(SpecialissueNo. 1, alsoissued 1981is        completewithout mentionof the activitiesof EdgarT.
entitled "The history of the Federation of Alberta Nat-   Joneswhose name is familiar to all perusersof the
uralistsand its corporatemember clubs."lSpecialIssue      WBBA annual report since1972.His impressive      contri-
No. 2 includesa few articlespreviously     publishedin    butionsto the bandingprogramare summarizedhere
other outlets,somedatingback to 1928-1940, well as        as are the many activitiesof the late Ken Trann, a most
new information presentedfor the first time.              enthusiasticyoungAlberta bander whosebiographyis
The paperby William Rowan,"The scientific   aspectsof
bird-banding"is every bit as applicabletoday as when                                         issue, very thorough
                                                          All in all, thisis in fact a special    a
it was originallywritten in 1928!This paper, produced     and enjoyableintroductionof bandingin Alberta, its
by one of the pioneersin migrationstudiesand band-        statedgoal,and a fitting tribute to Ken Trann to whom
                  plea for accuracy
ing, is an eloquent                 and experimental      it is dedicated.I can recommendit to all and at today's
designin banding as well as a condemnation the  of        pricesit is indeeda bargain.
type of "picnicbanding"  whichwe call "ring-and-fling"
                                                          Charles T. Collins
today!W. Ray Salt'spaper on recoveries Ferruginous
Hawks banded in Alberta and Kathleen Salt's light-

Page132                                   North American Bird Bander                                    Vol. 6, No. 4