Digiscope Applications for Shorebird Studies
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Digiscope applications for shorebird studies PATRICK R. LEARY 1291 S 3rd Fernandina Beach, Florida, USA. p.r. [email protected]. net Leary, P.R. 2004. Digiscopeapplications for shorebirdstudies. Wader Study Group Bull. 104: 34-38. Digiscoping successfullymarries the conventional function of spotting scopes(or telescopes)with technologicallyadvanced digital camerasto producehigh quality imageswithout compromisingroutine ornithologicalprocedures, thus offering biologists, researchers, and the like a highly convenientand economic tool to document sightings and observations.This paper addressesfundamental aspectsof this hybrid technology,field applications,equipment criteria, trouble-shooting, image processing and provides an appendix of Internet sourcesfor more in-depthinformation. INTRODUCTION engravedcodes or faded colour not readily evident in the field (Fig. 1). Furtherimages collected throughout the win- In 1999 when LaurencePoh of Malaysia discoveredthat he teringperiod also documented the progressionof moult and couldtake digitalimages of birdsthrough his spottingscope changesin plumagecoloration as springmigration neared. and subsequentlyshared this newsover the Internet,he gave Throughthe circulationof theseimages, another regional ornithologistsworldwide a revolutionarynew tool for docu- researcherexpressed a desireto documentPiping Ploversin mentingavian subjectsand behaviour.Soon dubbed "digi- his studyarea and I am currentlyengaged in systematically scoping",this hybrid technologyallows owners of spotting cataloguingbanded birds within hispopulation. On occasion, scopesand (certain) digital camerasto receivedual service the expediencyof digiscopinghas facilitated the documen- from both devices.By combininghigh power scopeswith tation of fleeting behaviour like the predator response camerasfeaturing internal optical and digital zoom lenses,it depictedin Fig. 2. is now possibleto obtainimages comparable in quality to In late winter, when Red Knotsreappeared, I resumedmy thoseformerly requiring a highlyexpensive arsenal of cum- populationsurveys, digiscoped flagged and banded birds and bersome,fragile and heavy telephotolenses and camerasas againtransmitted their imagesto distantresearchers. Given well as endlessquantities of costly film. recent declinesin rufa Red Knots visiting Delaware Bay, Searching for an economic and convenient means to researchersthere becamevery interestedin our sightingsof documentmy own sightingsof rare and bandedshorebirds SouthAmerican banded birds in NE Floridaand digiscoping in NE Florida, I recentlypurchased a Nikon Coolpix 990 for madeit possibleto shareobservations of markedbirds on a usewith my 82 mm Kowa scope.My timing was fortunate, daily basis.Remarkably, one image refuted a concurrent,but becausewithin daysof receivingthe camera,a southbound clearly erroneoussighting of the samebird far to the north. flock of 1,500 Red Knots Calidris canutustufa stoppedover Throughthis expeditiousexchange many contactsbecame in a local inlet and,among them were a few bandedindividu- awareof the high value andfunction of digiscopingfor field als worthy of documentation. research(Fig. 3). My initial effortsto digiscopethese birds proved remark- In additionto its digiscopingdudes, the 'unattached'digital ably simpleand straightforward, as was the subsequent view- camerafunctions well to documentflock size,habitats and site ing andediting of collectedimages on my homePC. Another features,invertebrate prey, disturbancesand more. Given its significantbenefit of digital photographybecame manifest compactness,convenience, image storage capacities, ease of whenthe imageswere expeditiouslyand conveniently trans- applicationwith the spottingscope and eliminationof com- mittedvia the Internet.Within daysof theirarrival in Florida, mercialfilm processing,my digital camerahas proven to be PatriciaGonzalez in far-distantArgentina was ableto recog- a highlyversatile, invaluable and economical research tool. nize and identify birds shehad bandedthere and the images documented Florida's first record of South American banded NECESSARY EQUIPMENT Red Knots. In subsequentmonths, digiscoping facilitated the docu- A broad range of scopesand cameras are employed for mentationof otherbanded birds in winteringpopulations of digiscoping,but higherquality scopes and cameras produce PipingPlovers Charadrius melodus and Semipalmated Plov- superiorimages. Although an inexpensivespotting scope ers Ch. semipalmatusand, like the Red Knot images,many coupledto an economicalcamera may be functional, the of thesephotos were conveyedto biologistsand researchers resultantimages will not compareto thosetaken with better acrossNorth America to supporttheir studiesand resolve equipment.However: in comparisonto conventionalfilm discrepanciesin band codesor identification. The latter photographythat demandsa camerabody and a multitudeof function has been especiallyvaluable to differentiate and expensivetelephoto lenses, digiscoping simply requires the documentsimilarly bandedbirds within the sameregional singlepurchase of a high qualitycamera. (A PC with appli- populationor migratoryflock. In a few cases,the high reso- cable softwareis alsorequired to view, edit, process,store, lution and magnification of band images has revealed copy and transmitimages.) Bulletin 104 August 2004 34 Leary: Digiscope applicationsfor shorebird studies 35 Spotting scope features Digital cameras Two basic scopefeatures are of greatestrelevance for digi- For digiscopingapplications the quintessentialprerequisite scopeapplications. Because increased optical magnification of all serviceablecameras is internal focusing and zoom requiresgreater light transmission,scopes with largerobjec- magnification.Because they meetthis essentialrequirement tive lenses(-80 mm) are more serviceablefor digiscoping and provide other highly desirable features, the Nikon thensmaller (60 mm) scopes.Most contemporarymodels are Coolpix900 or 4500 seriesof digitalcameras have long been available with either straight-throughor angled eyepiece favouredby digiscopers.The split,rotating body andlens of alignments.Straight-through is the mostconvenient for typi- thesecameras is particularly beneficial since it facilitates cal shorebirdapplications since it facilitatesthe timely loca- convenientcoupling while allowing full view of the LCD tion, centringand focusingof the subject;attachment of the screenand ready accessto all essentialcontrols. However, camera;and subsequentimage taking. The singleadvantage a variety of digital cameramakes and modelsare currently of angledeyepieces applies when digiscopingbirds or sub- employedfor digiscopingand, as technologyadvances, new jects well above the horizonthat requiresusers of straight- modelscontinuously appear in the market.(See Appendix for throughscopes to crouchwell below their tripodsto obtain Internet sitesoffering lists of scopeand cameramakes and similar views. Given the foregoing, potential digiscopers modelscurrently employed by individual digiscopers.) must consider their predominantmethod of observation/ It shouldbe notedthat for digiscopingapplications, the perspectiveand selecteyepiece alignment accordingly. photographeruses the camera's large LCD screenrather then Becauseof their versatility,many people use multi-power the viewfinder.Although the LCD imageis identicalto that zoom eyepieces and these are readily applied for digi- renderedin the scope'seyepiece, it will be somewhatdim- scoping.When combinedwith the internaloptical and digital mer and less sharp.Furthermore, bright sunlight tends to magnificationof contemporarycameras, some truly remark- washout the LCD image, but sufficientclarity is (usually) able, long-range imageshave been made. However, such retainedto permit oneto centreand zoom on a subjectprior imagingis impracticalunder typical field conditionbecause to tripping the shutterand often one's headwearprovides high power photographydemands extreme steadinessof sufficient shadeto view the screen (see Accessories). gear,stillness of subjectand ideal light andatmospheric con- Virtually all digital cameras are loaded with a mind- ditions. bogglingarray of functionsand options,but little time or I have experimentedwith a variable zoom (20-60x) and experienceis requiredto masterroutine procedures. Perhaps a fixed power(32x wide-angle)eyepiece with the latterprov- the functionof mostconcern to digiscopersis the selection ing to be more functionalfor digiscoping.The improvised of automaticvs. manualmode of operation.In my experi- joining of two highpower optical devices is inherentlyprob- ence,photographing both roostingand foraging shorebirds, lematic and the fewer distractionsthe greaterthe chanceof the automaticmode serves well. Digiscopingis highly prob- obtaininga good image. Increasedeyepiece magnification lematic and the more adjustmentsrequired in the field the alsoreduces the field of view (making it difficult to locate a higherthe likelihoodof failure or missedopportunities. As subjectin the camera's LCD (Liquid CrystalDisplay), exac- with conventional photography,superior results are best erbatescamera shake (blurring the image) andreduces light attainedin good light (preferably with the sun behind the transmissionto the camera(contributing to vignetting and camera)in close-proximityto the subjectand with camera slowershutter speeds and underexposure). andlens held motionless.Occasionally, insufficient light for The best camerasfor digiscopingoffer a range of inter- automaticoperation has compelledme to