An Inexpensive and Automatic Multiple-Exposure Photographic System

J. Field Ornithol., 66(1):37-43

AN INEXPENSIVE AND AUTOMATIC MULTIPLE-EXPOSURE PHOTOGRAPHIC SYSTEM

RICHARD G. BROWDER Departmentof Biology Virginia CommonwealthUniversity Richmond,Virginia 23284 USA

RICHARD C. BROWDER ScienceDepartment SalemHigh School Salem,Virginia 24153 USA

GREG C. GARMAN Departmentof Biology Virginia CommonwealthUniversity Richmond,Virginia 23284 USA Abstract.---Thispaper describesthe design,construction and deploymentof a simple automatic camera systemthat wasused to document the identitiesof scavengerson the carcasses of migratory fishes.The camera systemfunctioned properly in adverseweather during ex- tended deployment,and recorded a wide range of terrestrialvertebrate species under natural conditions.Bird speciesrecorded by the deviceincluded Red-shoulderedHawk (Buteolinea- tus), Common Crow (Corvusbrachyrhynchos), Turkey Vulture (Cathartesaura), and Great Blue Heron (Ardea herodias).The inexpensivephotographic system may have wider application to other studies of bird behavior and distribution.

UN SISTEMA AUTOM•TICO ECONOMICO PARA TOMAR MfJLTIPLES EXPOSICIONES FOTOGR3WICAS Sinopsis.--Sedescribe el disefio, la construcci0ny el montaje de un sencillo sistemafoto- giftricoque se us6 para documentarla identidad de animalescarrofieros que se alimentaron de los cuerposde pecesmigratorios. E1 sistemafotogr•tfico funcion6 bien bajo condiciones climfiticasadversas a travis del tiempo,y recopi16evidencia de una gran variedadde verte- bradosterrestres bajo condiciones naturales. Aves identificadas gracias a estesistema incluyen Buteolineatus, Corvus brachyrhynchos, Cathartes aura y Ardeaherodias. Este econ6mico sistema fotogrfificopuede tener un uso m•tsamplio en otros estudiossobre el comportamientoy la distribuci6n de aves.

Few descriptionsof inexpensivecamera systemsdesigned to document automaticallythe activitiesof birds and other wildlife have been pub- lished. Early camera systemdesigns employed a shutter releasemecha- nism that was manually reset between each exposure (Gysel and Davis 1956) or a movie camerawith a synchronizedflash (Dodge and Snyder 1960, Osterberg 1962). Carthew and Slater (1991) presentedan effective but relativelyexpensive multiple-exposure automatic photography system. Goetz (1981) describedan inexpensive,multiple-exposure automatic photography systemusing a polaroid-typecamera; however,the number of consecutiveexposures was limited by the size of the flash bar and film pack. We designeda simple, 35-mm automatic photographysystem that costunder $100 (U.S.) to documentterrestrial scavengers of post-spawn- ing blueback herring (Alosa aestivalis)carcasses.

37 R. G.Browder etaL J. FieldOrniihol. Winter1995

Tilt Board •cu•andbaited•i•ermechanisminthereadyposifion.1.Diagramøfcameramount, 12_Vbatter•con•olpanelshockabsorberassembly,

DESCRIPTIONOFDEVICE cameraCamera(Concordandmount.----Wemodel AW905)used anfeaturinginexpensive a motorized ($30) focus-free,film advance compact and threeanelectronicwooden flash.braces The(b)cameraand two (c) movablewas held tabson a(m)rigid (Fig.board 1). betweenA 3-cm thediameteroperatorhole towasaimdrilled the camera.in the Theboard camera, behindwith thetheview flashfinder (f) into theenable up nippleposition,(n)wasoverplaced theshutter in the button holder was andmounteda lever above arm (1)thewith camera. a rubberA 12- Vol.66, No. i AutomaticPhotographic System [39

9vDC

I I I ON-OFF

1K 2NO 9v TDDO MPS2907 ' 5 sec. 1N4001

½70uF MSW S2 (

1K 1NC 9¾ TDDO 50K MPS2907 90 sec. 1N4001

2200uF S1 --( 12v s• II 500rnp outo 1NO S5

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FIGURE2. Schematicdiagram of electriccontrol panel for the automaticcamera system. 40] R. G. Browderet al. J.Field Ornithol. Winter 1995

TABLEl. Basicparts list for automatic camera system.

Part description Quantity RelaySPDT, 7-9V 2L 2 Auto relay, 30 amp 1 Transistor MPS2907 2 Resistor PK2 1K, •,Sw 2 Resistor PK2 10K, •/Sw 2 Diode PK2 1N4001 2 Capacitor470MFD 1 Capacitor 2200MFD 1 Rheostat 50K control 2 Knob PK4, 1.91-cm 2 Miniature toggle switch 1 Batteryholder 6 "D" cells 1 Mercury bulb switch 1 Automotive throttle-return spring 1 Threaded rod 25.4- x 0.32-cm 1 Automotive electric door locker 1

V automobile door-lockmotor (d) waspositioned so that the lock linkage held the rubber nipple of the lever arm 3 mm above the shutter button. An adjustable shock absorber assembly,consisting of a small spring, threaded rod (r), two nuts, and two washerscushioned the impact on the camera, and an automobile throttle-return spring (t) retracted the arm. A slotted wooden beam was used as a base to hold the camera mount in a verticalposition. To weatherproofthe camera,a plywoodsplash guard was mounted below the camera holder and a roof was constructed from plywood and two wood strips.The base and roof were removable to fa- cilitate transport of the camera system. Trigger mechanism.--Fishcarcasses were secured with monofilament line to a tilt board, and the oppositeend of the board wascounter-weight- ed such that a slight downward force tilted the board (Fig. 1). When the herring carcasswas disturbed and the tilt board wasdepressed, a mercury bulb switch (s) completed an electric circuit. ElectronicpaneL--The systemcontroller consistedof two simple timing circuits.When the mercury switchon the tilt board wasclosed, relays S1, S2 and S3 were energized (Fig. 2). Relay S3 actuatedthe door-lockmotor causing the camera to take a photograph. The energized S2 relay de- energizedS1, and after an adjustabletime delay of 1-7 s, S1 "dropped out." When S1 dropped out, S3 immediatelydropped out and a spring retracted the lever arm. Also, S2 wasde-energized and dropped out with an adjustabletime delay of 20-90 s. The time delay dropout of S2 inhib-

FIGURE3. Red-shoulderedHawk (Buteolineatus) and Raccoon(Procyon lotor) scavenging on fish carcasses. Vol.66, I•o. I AutomaticPhotographic System [41 42] R. G. Browderet al. J.Field Ornithol. Winter 1995 ited another cycle.After S2 dropped out, another cyclecould be initiated when the mercury switchwas closed. The electronic panel and its 9-V power supplywere contained in a weatherproofplastic box. Systemhook- up involved three connectionsto the electronic panel: (1) the mercury switch,(2) the motor and (3) a 12-V automotivebattery. A list of specific camera systemcomponents is provided in Table 1.

RESULTS AND DISCUSSION In addition to low cost and portability, our systemprovided several advantagesover previouslypublished photographic systemsused to document the feeding activitiesof animals. Specifically,the systemrequired infrequent monitoring, photographed a wide diversityof taxa and organ- ism sizes,and when a clock was placed in the camera's field of view, the time of activitywas recorded. When the trigger device was placed at the camera's minimum focal length (1 m), the systemproduced good photographsand permitted easy identificationof scavengers(Fig. 3). Bestresults were obtainedusing ASA 100 film in the day and night. The flash tended to frighten animalsafter the first picture, but most returned to feed again. To prevent prolonged application of current to the door lock motor and to provide sufficient time for the electronic flash to recycle, the dropouts of the timing relays were set at 3 and 90 s, respectively.When the camera systemwas inactive, energy drain on the three power supplieswas minimal. The camera bat- teries (two AA alkaline cells) and the 9-V electronic control battery pack (six 1.5-V "D" cells) lasted -->5d. The automotivebattery was recharged biweekly. The systemperformed successfullyunder extreme weather conditions, including heavysleet and rain. During our study,the systemdocumented daytime scavengingby a feral dog (Canisfamiliaris) and four bird species: Red-shoulderedHawk (Buteo lineatus), Common Crow (C0rvus brachyrhynchos),Turkey Vulture (Cathartesaura), and Great Blue Heron (Ardea herodias).At night, opossum (Didelphisvirginiana), raccoon (Procyonlo- tor), and northern water snake (Nerodiasipedon) were photographed. This photographic systemis applicable to other studiesbecause the trigger mechanism can be anything that closesor opens an electrical circuit. Other possibilitiesto document the presenceof animals along trails and runwaysinclude a trip wire or a motion detector.An infrared break- beam mechanismwas employed initially as a trigger by the present study, but was later replaced by the tilt-board becausethe former mechanism wasactivated by the large number of insectsattracted to the fish carcasses.

LITERATURE CITED

CA•THEW,S. B., ANt) E. S•TER. 1991. Monitoring animal activitywith automated photography.J. Wildl. Manage. 55:689-692. DODGE,W. E., AND D.P. SNYDER.1960. An automatic camera device for recording wildlife activity.J. Wildl. Manage. 24:340-344. GOETZ,R. C. 1981. A photographicsystem for multiple automatic exposuresunder field conditions.J. Wildl. Manage.45:273-276. Vol.66, No. I AutomaticPhotographic System [43

GvsrI•,L. W., ANI) E. M. DAVIS,J•t. 1956. A simple automaticphotographic unit for wildlife reseach.J. Wildl. Manage. 20:451-453. OSTERBERG,D. M. 1962. Activityof small mammalsas recorded by a photographicdevice. J. Mammal. 43:219-229. Received16 Aug. 1993; accepted 18 Mar. 1994.

SIGURD OLSON ENVIRONMENTAL INSTITUTE SIGURD T. OLSON COMMON LOON RESEARCH AWARD

LoonWatch is acceptingapplications for its ninth annual award for research on Common Loons in the Upper Great Lakes Region of the Unit- ed Statesand Canada,To applyfor cashawards up to $1000,a proposal (max. 10 pages) of the researchand a curriculumvitae should be sub- mitted by the principal investigatorto Terry Daulton, Coordinator, LoonWatch, Sigurd Olson Environmental Institute, Northland College, Ashland,Wisconsin 54806. Proposalsmust be receivedby 10 Jan. 1995. Proposalsby studentsshould be accompaniedby two letters of recom- mendation. The award will be granted on the basisof the project's po- tential to improve our understandingand managementof populationsof Common Loons in the Upper Great Lakes Region. Guidelinesfor appli- cations are available from LoonWatch