Counting Animals from Space:

Chapter TwoTransitions from Captivity to

Wild Places

Scott Bergen & Eric Sanderson

Why Count Wildlife?

• Fundamental to Conservation

• Foundational to Population Studies

• Federal Programs Spend Millions of Dollars Annual to Count Animals

Nov. 10, 2004

10:52:45 am

35 people involved

21 keepers

15 Volunteers

28 Enclosures mapped for individual animal locations

300 Faux fur targets placed in 4 ‘habitats’Digital Globe Inc ©

Ground –vs- Sky

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Information Shadow

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Tallying Identification by Species

Logit (identified targets) = -3.666 + 0.019(Color) + 0.970(Size) - 0.230(VegHt) - 0.421(Shade).

National Elk Refuge. Jackson , WY

Counting Animals• Most reliable estimate use transect with repeat

measures• Population estimates w/ standard deviation • Findings usually extrapolated from small area to

available habitat or other limiting feature• Costly to count animals on ground

• Remote sensing rarely used (aerial imagery)• Time and scale rarely match satellite scale & time• Mismatch in terms of time and location in reference to

identifying- verifying high spatial resolution satellite imagery

Why the National Elk Refuge?

• Reliable elk & bison congregations during winter

• Logistic regression equation shows good fit for size, color, vegetation and shadow

• Annual census of both elk and bison

Animal Count Comparisons

• Refuge level, elk (weekly), bison (annual)

• Ground census estimate @ time of satellite acquisition

• Panoramic photo estimate @ time of satellite acquisition

• Heads up digitizing estimate

• Object oriented estimate

Jackson Wyoming

• Access limited• Freakin’ cold

-20f• Snow

bleaching histogram of sensor

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Ground Census of Elk Group

• High Ground limited

• Limited by distance

• 1360 individuals

• 60/40 female- male ratio

Thick In Elk

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Panaramic Resesults

• Verified over 1,000 elk sex, position, direction position in less than 10 seconds

• Estimated 1070 individuals

• 679 females, 299 males, 89 ?

• Knew there were more but individuals > 1km were not identifiable as well as those totally blocked by other elk

• 1503 individuals

Heads up

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Object Oriented Approach

• Scale based segmentation

• > classification• > revision• >classification• Hierarchical

strutured• Means both

smaller and larger

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Segmentation• Adds new

dimensions to data

• Area, spectra, variability within polygons

• Adjacency• Contextual• Generates

data Important to distinguish animals and differentiate types of animals

Initial Classification

• Good Results

• Identified 1540 individuals

• Misidentification within riparian areas

• Grouped elk in close proximity

Classification• Refined with an area classifier

• 1482 individuals

• Further refinement, standing – sitting, elk vs bison, sexes in bison

Further refinement

Summary of Animal Counts

• Park Estimate: 4,900 elk, 951 bison

• Ground Estimate: 1,360 elk, 60/40 f/m

• Panoramic: 1,071 elk, 69/31 f/m

• Heads up: 1,503 elk

• 1st Object Oriented Class: 1,540

• Ob. Orient w/ Area: 1,480

Future Considerations