law form camouflage pattern animal coloration animal darker upper lighter underside body pattern found species mammals reptiles birds fish insects existed cretaceous period light falls uniformly coloured object sphere makes upper appear lighter underside darker grading pattern light shade makes object appear solid acts visual cue makes object easier detect reduces ease detection predators prey effects self typically grading dark light theory useful military camouflage practice rarely applied despite best efforts artist zoologist precise function patterns animal coloration debated suggestion multiple functions including background matching viewed background matching viewed implying separate colour schemes surfaces outline variety largely non camouflage theories related mechanism counter illumination adds creation light lamps match actual background counter illumination camouflage common marine organisms squid studied prototype stage military use ships aircraft rarely warfare reverse belly darker contrast makes animals conspicuous found animals defend pattern displays signal warn experienced predators animals live upside lack strong defences like upside camouflage early research english zoologist author colours animals discovered insects including purple emperor butterfly iris larvae use term suggest effect occurred widely new_hampshire artist study write book animal kingdom correctly described illustrated photographs paintings claimed animals reason called law wrote animals painted nature parts tend sky light vice versa fact vast majority creatures animal kingdom wear developed minute degree famous hard homes speaks observed painted number examples including upside feeding position makes appear flat artificially inverted position sunlight inverted combine appear heavily shaded solid obtained patent paint warships submarines surface ships failed convince navy adopt ideas book animals described instances following general approach criticising excessive claim says patterns colors whatsoever animals prey preyed certain normal circumstances effectively animals calls theory fantastic extreme include books photographs non white white background point words object matter background words colour resemblance sufficient afford explains contrary expected lacking artistic perception bird appears highly conspicuous looking lighter breast darker background actual fact background breast pure white application animals observed wide range animal groups terrestrial deer marine sharks basis camouflage predators prey alongside forms camouflage including colour matching coloration predatory fish gray effectively flattened hunts invisible prey fish sands marine animals include blue shark herring fish like sergeant fish patterned stripes spots tones canvas painted leopard spots tiger stripes dress universally worn essential uniform adopted deer repeated extensively provides basic great majority snakes amphibians insects reaches fine state perfection different rivers surface waters sea reaches maximum development significance existed marine reptiles cretaceous period skin dark coloured reveals turtles dark backs light related mechanism counter illumination form animal camouflage uses increase average animal match background called counter illumination common mid water fish invertebrates especially squid makes counter illuminated animal practically invisible predators viewing counter illumination camouflage seen extension achieve shadows counter illumination add actual lights permitting effective camouflage changing conditions including background bright animal counter illuminated appear shadow military like counter illumination rarely applied practice military camouflage military authorities unaware world war second world war proposed countries armed forces demonstrated effectiveness succeeding armed forces adopt technique influenced military adoption camouflage general world war camouflage ships remained influential inspector camouflage political argument developed invited camouflage inch rail mounted gun alongside similar gun conventionally carefully combined contrast break gun barrel outlines appearance solid cylinder guns photographed air angles view results remarkable gun invisible minute scrutiny knows exactly look look gun highly visible authorities appearing embarrassed evidence right posted middle_east unsuccessfully intervened pleading guns painted way brought home australian zoologist book art camouflage followed describing detail book reprinted military handbook photographed model birds argued shoulders arms described war department principles camouflage theory use nature advice given upper surfaces painted conform color tone surrounding country background sides graded toned white surfaces parts shade painted continued advocate military usage example patent personal camouflage including form statistical varying sizes rounded dark patches lighter ground research investigating camouflage breaking automated detection objects tanks showed images looking graded shadows break strong camouflage human viewers precisely images searched places gradient crosses zero line shadow stops darker starts lighter technique defeated camouflage disruption edges authors observed animals counter measures based implied predators use based function reviewing years observed defines darker surfaces exposed lighting common poorly understood aspect animal coloration noted debate works considered evidence theory acts camouflage reducing ventral reviewed alternative explanations camouflage theories wrote include self shadow results improved background matching viewed self shadow form viewed background matching viewed body outline viewed examined turn background matching viewed like argued animals hard fade notes reviewing theory reinforcing view act eliminate effects ventral measured effect grey showing horizontal self belly partly concealed vertical climbing tree trunk effect occur original argument nature exact opposite artist paint creating illusion solid effect shade form powerful cue animals different identify shapes objects research chicks showed preferred grains shadows falling illuminated humans birds use depth cue background matching completely different function animal military vehicle coloration camouflage surfaces differently match backgrounds respectively noted example fish common find upper surface dark coloured lower surface white animal seen early researchers including argued marine animals including fish sharks upper lower surfaces sharply distinct tone dark upper surface nearly white lower surface suggested seen darker dorsal surface animal offer camouflage darkness deep water seen lighter ventral area similarly provide possible contrast ocean surface evidence birds birds catch fish medium depth surface coloured way prey birds underside bird concluded possible role coloration patterns needs evaluated separately assuming functions effectively outline identified additional mechanism previously analysed round body like cylinder illuminated seen appears dark sides graphics tool demonstrated effect flattened predators known use edges identify prey argues prey harder detect seen non camouflage theories non camouflage theories include protection light protection plausible theories remained largely according evidence despite demonstrations examples little experimental evidence effectiveness gathered century discovery experiments artificial prey showed objects survival benefits study colleagues showed species closely matched predictions self shadow function predicted mechanism evolutionary developmental biology assembled evidence evolution acted scales organism individual genes proteins genetic switches case mammals dark brownish upper parts lighter buff whitish parts house mouse gene creates difference protein signalling specifically action absence protein alpha cells bearing produce dark skin fur dark brown black presence protein system produces lighter coloured yellow red genetic switch active cells embryo belly skin causes gene active creating seen adult mammals reverse shadows reverse belly contrast adding natural fall light pattern animal coloration found animals like honey strong defences offensive sharp claws aggressive nature honey animals run attack slowly turning face danger giving threat displays inexperienced predators signal warn experienced ones discovered phrase relation attitude shaded light grading dark belly reason animals including eyed live upside belly similarly sea reverse associated inverted habits animals employing usual way camouflage examples animals pioneering books animal coloration account principal facts theories relating colours markings animals animals coloration animal kingdom exposition laws disguise color pattern summary discoveries wallace exposition theory natural selection applications general reading bruce encyclopedia perception volume sage behavior forbes peter camouflage yale history theory evidence cryptic function stevens martin animal camouflage mechanisms function speed avoiding attack journals allen nicholas december test predicted relationship lighting environment american naturalist november principles camouflage tactical technical trends roy february non scientific reflections camouflage art war philosophical transactions retrieved white plumage sea birds nature survival value wild birds predators biological journal society ann art nature science war attached shadow orientation perceived depth chickens environment illuminated jones hawaiian squid testing hypothesis image processing approach animal behaviour ocean life mammals retrieved january october notes larvae etc transactions october notes larvae etc transactions present day learned function speed kelly david function animal behaviour speed kelly bird species ecology multiple names authors list link based retrieved january kurt december advanced camouflage system method patent application publication retrieved january young animals evidence living squid science young intensity regulation living animals
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