Photo Identification methods
CONTENTS
CONTENTS 1
USES OF PHOTO ID 2
TAKE PICTURES 2
WORKING CONDITIONS 2
UTIFITY 3
CRITERIA SELECTION PHOTO 5
SAMPLING 5
ERRORS 8
DISADVANTAGE 8
DATA COLLECTION 8
DATA ANALYSIS 8
OUR OBSERVATION - EXAMPLE PHOTO - ID 9
HUMPBACK WHALE 9
MINKE WHALE 11
WHITE - BEAKED DOLPHINS 12
DEDUCTION 14
REFERENCES 15
SUPPLEMENT 16
CHECKLIST USED PICTURE 16
OTHER INTERESTING PICTURE TAKE DURING USE PHOTO - ID 16
USES OF PHOTO ID
Photo identification it use for watching and determining animals behavior, population biology and ecology. For example animals behavior can be group composition, social interactions and focal animals behavioral observations. For example population biology can be life span, birth rate, mortality rate and abundance estimates.
Population must be definable because at least two and preferably more animals. Should be made to try to ensure that all animals have an equal probability of being captured during any one sampling. Should be made to try to ensure that all animals have an equal probability of being captured during any one sampling occasion. Better chance to capture the animals with a high probability of bias caprure number of recaptures up and leads to underestimation of population size. Identify an invidual animals is possibly, because we photographing sample of animals at deferent places - > enable movement and migration. It can also provide information on the identity unit in the population.
Temporary emigrations, where animals may not be available at every sampling occasion, also adversely affect such analyses. Identifying features are vary between species. This allows us to identify individual species.
According to Weinrich (2001): "If observers noted any distinctive dolphins, an attempt was made to photoidentifity them. Two classes of distinctive individuals were noted. Some animals were immediately recignizable through highly prominent marks, including partly missing dorsal fin or large amounts of white pigment on the dorsal fin or flanks.. This white coloration has been noted in several other odontocete species, although it is unknown wherther it is a permanent, genetically determined pattern."
Advantage are no physical harassment and minimal disturbance to the study populatio.
TAKE PICTURES
We make photographie dorsal fin on minke whale, doplhins and killer whale; fluke on humpback whale and fin whale; body on doplhins and killer whale. We make photographie head also.
In the resulting photographs are follow in dorsal fin nicks, notches, shape, scars and scratches; in fluke color papetters, scars;in body color patterns, scars and scratches; in head callosities.
Colour patter and shape are different fron other recognition cues because they can readly be stored an a photograph as a pernament record of a invidual.
WORKING CONDITIONS
This method is highly dependent on the weather and the properties of the sea. The sea should be calm, or with small waves. Large waves deteriorating visibility. Any creature in the waves do not hardly see. Moreover, when large waves, the ship rocks, making it difficult our stability and the problem is to make high-quality photos. Another prerequisite is the weather, as it works with a fairly complex technology. Most camera should get slightly wet. In addition, rain on the lens degrade photo. Bad weather also usually accompanied by poor visibility, which we also impedes the acquisition photo. Minor problems in the weather can be solved by setting camera. More camera settings are read in aids. Photo - ID usually works with another method of visual matching.
Work in the terrain
The main activities in the field is the acquisition of images of the animals. We can take images of the ship or aircraft. Important is the distance from the animals. For small cetacean species is suitable distance <20 m, with larger species of cetaceans is a good distance of 60 meters or more. It is important to have suitable conditions of weather and sea conditions.
Work in the lab
Main load work in the lab is classification and organization photograph especially. First step is classification photograph along quality. We used classification ...
This is a preview of the whole essay
Work in the terrain
The main activities in the field is the acquisition of images of the animals. We can take images of the ship or aircraft. Important is the distance from the animals. For small cetacean species is suitable distance <20 m, with larger species of cetaceans is a good distance of 60 meters or more. It is important to have suitable conditions of weather and sea conditions.
Work in the lab
Main load work in the lab is classification and organization photograph especially. First step is classification photograph along quality. We used classification do 3 group, when in first group was too bad photograph - smudged, lodging all animals, low quality. Into second group we include photograph which relatively excellent. They had quite good quality but to excellence them something be absent. Into third group we get photograph which fulfilmented all terms which should have. Third group we classification along partner and after along determination mark - dorsal fin, fluke atd. This we made of photograps from all days Of each categories and of each day we chose one excellent photograph.
To better and comfortable determinate partner possible use special computer software. Important thing is make advance all photographs. Next step in the lab should be setting up catalog cards. In the cards point out in speciality set animals, time a datum photograph.
UTIFITY
Camera
The camera must be such that could set the ISO, aperture, etc.
To achieve the correct composition, high klality, focus, etc. is achieved by setting the ISO, time or aperture. First set the ISO, weather set the 100 to 400 set the overcast weather, night or in low lighting set the 800 to 1600, or specify the exposure flash. Then the worse light conditions = greater sensitivity ISO.
Furthermore, if we choose to set the priority or aperture priority time. Taking into account the first of "aperture priority" for the photography of animals, which lies on the grass and moves around the screen set to 6.3. When we need to have a sharp image, the more value we set the aperture.
If the animal is moving, we switch to the "Priority" and moving the animals to set time of 1 / 500, 1 / 800, 1 / 1000, calmly and higher, thus eliminate the blurry photos caused by the movement object. It follows that the more and faster the object moves, the more we need to set a shorter time of exposure, and vice versa, if I take pictures where little light is set longer exposure time.
Regarding our case, photographing animals from the whale - watching the ship. That sets the ISO around 100 - 200, around the time of 1 / 800 and aperture 6.3 - 8 Appropriate to set the priority of time. It is also possible to set a time of about 1 / 1600 to 1 / 2000th If we succeed in capturing the whale as it surfaces to the surface and breathe water droplets, so you will have beautiful "paused in the air."
GPS
GPS need for accurate time setting on the camera. Before each work a taking a GPS must be clearly recognizable time. After sorting the photos, the timing of the time use camera adjusted for the errors of the difference GPS.
Whale - watching ship
The ship is required to obtain high-quality photos. We could hardly the photographs from the shore and taking pictures whales at a distance of about 2 km. Ship should be stable, should not be too much sway.
Paper, pen
Paper and pencil needs to record information on the incidence of species, time of occurrence. Sliuží then to improve the identification of species on photographs.
CRITERIA SELECTION PHOTO
Criteria selection are mainly hight quality. When the poor quality are of the wrong kind of recignition, movement atc. When the right quality are possibility of identifying animals.
We can provide hight resolution. When the quality resolution are well recognizable characters.
Photo can have full frame images of identifity features. Another necessity is that the images were all for a good identification of elements.
Other criteria is for flukes straight behing. Flukes should be as straight as you can see in the picture, no shot.
For body and dorsal fins can left side and perpendicular to the animal. In the examining the body and the dorsal fi should be shot with left side and perpendicular to the animals (90° angle).
The photo is also important to spread the light. Photo may not be too much glare and even dark.
SAMPLING
Sampling must be representative. Sampling must fulfilment requirements given highhess. I present bed and good photo these requirements of our observation here.
High quality
IMAGES 1:- POOR QUALITY
IMAGES 2 : RIGHT QUALITY
High resolution
IMAGES 3: QUALITY RESOLUTION
IMAGES 4: SLOPPY RESOLUTION
Full-frame images of identifying features
IMAGES 5: POOR PHOTO
For flukes straight behind
IMAGES 6: GOOD SHOOTING
IMAGES 7: BAD SHOOTING
For body and dorsal fins: left side and perpendicular to the animal
IMAGES 8: RIGHT SHOOTING
IMAGES 9: POOR SHOOTING
ERRORS
Incurred errors could aportion into two groups and errors of picking dat and errors of analysis.
DISADVANTAGE
The main deficits of this method are time and labour intensive, indistinguishable or similar individual markings, deterioration or changes in natural markings with time and human error or identification errors.
I think the main problem of this method is being changed inviduálních brands. For example, we determine a whale for such and such an individual by scars. After months or even longer when you snap it again, but meanwhile she came to more injuries, which overlaps the original scar and we can not see it. Easy so happens that we have known the whale will be included in the catalog as new, although not new at all.
Another serious problem to my mind is human error identification, one can easily overlook some pictures on the natural inviduální brand. Another negative is the fact that we are not always able to take a beautiful picture, by which we identify safe whale. Photo may well be a sharp, high quality, but not always on it may appear that, according to what different types of leaders.
DATA COLLECTION
Data with picking develop mainly thanks to difference between animals in the population.- markings and capture probalities. Errors from picking dat divide in variation in capture probabilities and variation in markings/identifiable features. Variation in capture probalities are biological (age, sex), heterogeneity. Important factors is temporary emigration (animal absent, limited sampling effort). According to Hammond 1990: "Greater range of capture probabilities leads to negative bias in population estimates".
Variation in markings features are difference among animals. Some individuals better marked than others, therefore more easily recognised. On unidentifiable animals not represented in sample, population size underestimated. Tato chyba se dá opravit. Estimate proportion well marked individuals in school encountered to estimate number of identifiable animals in population. Some marks lost or change over time, leads to overestimation of population size.
DATA ANALYSIS
It is human errors mainly in matching photographs. Errors take apportion in false positives and false negatives. Among false positives can include categorising different animals as the same individual. Which lead to underestimation of population size. Among false negatives can include missed matches. Which lead to overestimation of population size. Error rate increases with reduced photo quality and fatigue. That possible overtake grade photos and limit matching to two hour periods.
OUR OBSERVATION - EXAMPLE PHOTO - ID
Present data are take from 27 august to 3 sept and taken the best photo from each encounter to identify. Per all period we are observation 3 patner - humpback, minke whale and white - beaked dolphins.
Observation procced in Skjálfandi Bay, near city Husavík. Skjálfandi Bay is bay Atlatic ocean. In the Skjálfandi Bay predominante Iceland coastal water, then of coastal premoninante relatively warn and squine.
Sea was into majority case calm, with small wave. Last day (3.9.) sea was a bit heavy, wave was larger.
Weather was quite good, sunny - side brightness into majority case. Last day (3.9.) weather was overcast. It was breezy, sometimes it was showery. It was misty sometimes.
Lighting conditions was satisfactory.
HUMPBACK WHALE
This whale was observation by 4 encourter (1.9., 2.9. - morning, afternoon, 3.9.). The best photograph is photo from encounter 3 (02.09.09, 15:23)
Encourter 1
IMAGES 10: ENCOUNTER 1 - PHOTOGRAPHED: 01.09.09, 14.47
This is okay focus, bad angle a little dark, difficult to look at the trailing edges, and distinct marks are just visible. Rectify might practise of camera for better focus etc...
Encounter 2
IMAGES 11: ENCOUNTER 2 - PHOTOGRAPHED: 02.09.09, 11:44
This is good photo, good angle, glare on edge, unclear at the side. Can see distinctive black and white markings.
Encounter 3
IMAGES 12: ENCOUNTER 3 - PHOTOGRAPHED 02.09.09, 15:23
This is excellent photo, good focus, great angle, lighting is excellent to see distinctive markings and make out trail edge. Barnacles on edge.
Encounter 4
IMAGES 13: ENCOUNTER 4 - PHOTOGRAPHED 3.9.2009, 18:28
This is good focus, trail edges blur due to angle. Can see marking distinctively. Lighting good. Barnacles. being on a whale watching boat instead of research boat for getting perpendicular shot.
MINKE WHALE
Minke whale was observation by 2 encounter (27.8. and 2.9. morning).
Encounter 1
IMAGES 14: ENCOUNTER 1: PHOTOGRAPHED 27.8.2009, 14:46
This is good focus. Quality is good. Good is resolution, shooting dorsal fin.
Encounter 2
IMAGES 15: ENCOUNTER 2: PHOTOGRAPHED 2.9.2009, 10:33
This is okay focus. It is good see dorsal fin, but it isn´t hight quality and hight resolution, but determination is possible.
WHITE - BEAKED DOLPHINS
White - beaked dolphins was observation by 3 encounter (1.9.2009, 2.9.2009 - morning, 3.9.).
Encounter 1
IMAGES 16: ENCOUNTER 1 - PHOTOGRAPHED 1.9.2009, 15:10
This is excelent photo. It is hight quality, resolution, good shot dorsal fin. It is good recognizable invidual marks in hill dorsal fin.
Encounter 2
IMAGES 17: ENCOUNTER 2 - PHOTOGRAPHED 2.9.2009, 11:04
This is good focus. It isn´t hight quality, resulion. It is good shot dorsal fin. It is possible determination invidual.
Encounter 3
IMAGES 18: ENCOUNTER 3 - PHOTOGRAPHED 3.9.2009, 18:35
This is good photo. It is good quality, resolution, good shot dorsal fin. It may better lights and resolution, but it is possible determination.
DEDUCTION
Methods photo - id uses for biological observations, ecology, population estimates. Resulting photograph grading high quality to low quality and species dependent. Errors can occur in identifying marks. Errors in data collection and analysis.
During our observation we see 3 patertns animals - humpback, minke whale and white - beaked dolphins. We take around 900 photo, with which we chose good photo, on dolfin was 33, on humpback whale - fin was 157 and fluke 83, on minke whale was 9. From this photo we chose best photo for each peterns and each day.
The best photo on humpback is photo of 2.9.2009 - 15:23. The best photo on minke whale is photo of 27.8. 2009 - 14:46. The best photo on white - beaked dolphins is photo od 1.9.2009 - 15:10.
REFERENCES
* Evans, P. G. H., Hammond, P. S., 2004 Monitoring cetaceans in European waters. Mammal Rev. 34(1) pp. 131-156
* Carlson, C.A., Mayo, C.A. & Whitehead, H. (1990) Changes in the ventral fluke pattern of the humpback whale (Megaptera novaeangliae), and its effect on matching. Report of the International Whaling Commission, special issue,12, (in press).
* Hammond, P.S. (1990) Heterogeneity in the Gulf of Maine? Estimating humpback whale population size. Report of the International Whaling Commission, special issue,12, (in press).
* Sears, R., Williamson, J. M., Wenzel, F.W., Berube, M., Gendron, D. and Jones, P. (1990) Photographic Identification of the blue whale (Balaenoptera musculus) in the Gulf of St Lawrence, Canada. Sc/A88/ID23.
* Miller P., Rasmussen M., Magnusdóttir E., Antunes R., Alves C. A., (2009) Studying marine mammals in the wild, presentation to course
* Weinrich M.T., Belt C.R., Morin D., 2001 Behavior and ecology of the Atlantic white - sides dolphin (Lagenorhynchus acutus) in coastal new England waters. The Whale center of New England
SUPPLEMENT
CHECKLIST USED PICTURE
Images 1:- Poor quality 5
Images 2 : Right quality 5
Images 3: Quality resolution 6
Images 4: Sloppy resolution 6
Images 5: Poor photo 6
Images 6: Good shooting 6
Images 7: Bad shooting 6
Images 8: Right shooting 7
Images 9: Poor shooting 7
Images 10: Encounter 1 - Photographed: 01.09.09, 14.47 9
Images 11: Encounter 2 - photographed: 02.09.09, 11:44 10
Images 12: Encounter 3 - photographed 02.09.09, 15:23 10
Images 13: Encounter 4 - photographed 3.9.2009, 18:28 11
Images 14: Encounter 1: photographed 27.8.2009, 14:46 11
Images 15: Encounter 2: photographed 2.9.2009, 10:33 12
Images 16: Encounter 1 - photographed 1.9.2009, 15:10 12
Images 17: Encounter 2 - photographed 2.9.2009, 11:04 13
Images 18: Encounter 3 - photographed 3.9.2009, 18:35 13
Images 19: Dolhpins - 1.9.2009, 15:10 16
Images 20: Dolhpins - 3.9.2009, 18:24 16
Images 21: Humpback whale - 1.9.2009, 14:27 16
Images 22: humpback whale - 1.9.2009, 15:06 18
Images 23: Humpback whale - 2.9.2009, 11:32 18
Images 24: HumpBack whale - 2.9.2009 - 14:43 18
Images 25: Humpback whale - 3.9.2009 - 18:16 19
OTHER INTERESTING PICTURE TAKE DURING USE PHOTO - ID
IMAGES 19: DOLHPINS - 1.9.2009, 15:10
IMAGES 20: DOLHPINS - 3.9.2009, 18:24
IMAGES 21: HUMPBACK WHALE - 1.9.2009, 14:27
IMAGES 22: HUMPBACK WHALE - 1.9.2009, 15:06
IMAGES 23: HUMPBACK WHALE - 2.9.2009, 11:32
IMAGES 24: HUMPBACK WHALE - 2.9.2009 - 14:43
IMAGES 25: HUMPBACK WHALE - 3.9.2009 - 18:16
