Mapping Black-tailed Prairie Dog Colonies Mapping Black-tailed Prairie Dog Colonies Across Montana Using the National Agriculture Across Montana Using the National Agriculture

Imagery Program (NAIP) 2005 ImageryImagery Program (NAIP) 2005 Imagery

Bryce Maxell, Interim Director / Senior Zoologist(406) 444-3655 bmaxell@mt.gov

Scott Blum, Biologist / Information Specialist

Karen Walker, Biological Data System Coordinator

March 13March 13thth 2010, Great Falls, Montana 2010, Great Falls, Montana

http://mtnhp.org

Montana’s Conservation Plan forBlack-tailed and White-tailed Prairie Dogs

• Objective #2 - develop statewide and regional prairie dog distribution and abundance standards

- Inventory and monitor distribution and abundance

- 7 km complexes of 5,000, 1,000-5,000, and <1,000 acres- 1.5 km complexes of 5,000, 1,000-5,000, and <1,000 acres (Biggins et. al. 2006)

• Objective #3C – identify isolated praire dog colonies in need of special consideration, assess their needs, and implement special management tasks, as appropriate

Datum Shift?

Weaknesses in Current Spatial Representation

Missed Town

Weaknesses in Current Spatial Representation

• Shifted PolygonsMissed ColoniesGround Mapping Limitations (can’t see the town for the burrows)

Weaknesses in Current Spatial Representation

National Agriculture Imagery Program

• Administered by USDA Farm Service Agency• 4 bands of information (red, green, blue and near

infrared) gathered during growing season in continental U.S. to yield both natural color and color infrared imagery

• Acquired at 1-meter ground sample distance or resolution (i.e. each pixel = 1 square meter)

• Horizontal accuracy = 6 meters• Montana first flown in 2005 (available in 2006)• MT flown again in 2009 (available March 4, 2010) • Add 2009 NAIP to ArcMap under ArcGIS Server

Connection http://gisservice.mt.gov/arcgis/services/

Goals

• First step toward evaluating use of NAIP imagery for digitizing prairie dog colonies

• Statewide spatial representations for areas with recent evidence of prairie dog activity for environmental reviews

• Summaries of colonies and complexes by various administrative units

• Identification of complexes for management and potential Black-footed Ferret reintroduction using both 7 km and 1.5 km rules

Methods 1• Use existing point and polygon data to create a

Maxent predictive distribution model• Stratify a network of 717 20 km x 20 km grid tiles

into high, medium, and low density areas• Test mapping effort on a random selection of 92

20 km x 20 km grid tiles• For each tile, blindly evaluate 1 hectare grid cells for

evidence of recent prairie dog activity (code = 1) using 2005 NAIP color and IR, MaxEnt model, slope model, and black and white DOQQ imagery at scales between 1:5,000 and 1:30,000 (1:10:000 seemed to work best)

• Turn on existing point, polygon, and flight data and evaluate against grid cells turned on

• Revaluate areas without recent evidence recorded and if evidence is detected (code = 2)

Maxent Model for Black-tailed Prairie Dogs

Black Points = current point observations and colony centroidsModel is a logistic surface varying from 0 to 1. Warmer colors predict more suitable habitat

Maxent Model Used to Develop Density Strata(Red = High, Green = Low, Blue = No Previous Documentation)

* Grid Tiles are 20 km x 20 km

Density Strata Relative to Existing Point Data (Red = High, Green = Low, Blue = No Previous Documentation)

* Grid Tiles are 20 km x 20 km

Pilot Mapping on Random Grid Cells (blue outline)

* Grid Tiles are 20 km x 20 km

Code = 1 for 1 Hectare Grid Cells on each Tile with Evidence of Recent Prairie Dog Activity

Compare Grid Cell Coding Versus Points, Polygons, and Flight Lines at 20x20 km scale

Compare Grid Cell Coding Versus Points, Polygons, and Flight Lines at 20x20 km scale

Code = 2 for Grid Cells That Second Review shows Evidence of Recent Activity

Missed on Initial Pass

Slight Discrepancy with 2008 Flight Line

Flight Line, but No Burrows Evident

Odd Mottling Not Coded as Recent Activity

Beware of Hay Bales

Initially Looks Possible, but on Side of Hill

Burrows?

Burrows?

Difficult Landscape 1

Difficult Landscape 2

Difficult Landscape 3

Problems with IdentifyingWhite-tailed Prairie Dog Colonies

What are these white features?

Methods 2• Stitch tiles together• Dissolve adjacent grid cells into colonies• Apply 750, 1,500 and 3,500 meter buffers to

identify 1.5, 3, and 7 km complexes• Calculate total area of complex• Code complexes by BLM Field Office, FWP

Region, Tribal Reservation, Forest, and Stewardship

• Evaluate complexes relative to Goals in Montana’s Conservation Plan

• NEED TO EVALUATE ACCURACY WITH GROUND TRUTHING!

Example for 1.5 and 7 km Complexes

Potential Colony and Complex Summary• 8,852 potential colonies (2,598 of these corroborated with previous info)

- 0 ≥ 5,000 acres- 22 between 1,000-5,000 acres- 8,830 ≤ 1,000 acres- smallest = 2.5 acres, largest = 2,945 acres

• 289 of the 7 km complexes- 6 ≥ 5,000 acres- 16 between 1,000-5,000 acres- 267 ≤ 1,000 acres- smallest = 2.5 acres, largest = 397,086 acres

• 1,032 of the 3 km complexes- 16 ≥ 5,000 acres- 42 between 1,000-5,000 acres- 974 ≤ 1,000 acres- smallest = 2.5 acres, largest = 109,883 acres

• 2,474 of the 1.5 km complexes- 10 ≥ 5,000 acres- 73 between 1,000-5,000 acres- 2391 ≤ 1,000 acres- smallest = 2.5 acres, largest = 38,766 acres

Note: Acres have not been verified with ground truthing andare certainly an overestimate ofon-the-ground acres due to the 1 Ha mapping unit used in thiseffort and likely misidentificationof other features as colonies.

NAIP (Black) Old Points (Purple) 2008 Flight (Red)

Colony Stewardship(Private = Gray, Federal = Yellow, State = Blue, Tribal = Brown)

6 x >5,000 Acre 7 km Complexes

7 km 5,000 Acre Complex Stewardship(Private = Gray, Federal = Yellow, State = Blue, Tribal = Brown)

16 x >5,000 Acre 3 km Complexes

3 km 5,000 Acre Complex Stewardship(Private = Gray, Federal = Yellow, State = Blue, Tribal = Brown)

10 x >5,000 Acre 1.5 km Complexes

1.5 km 5,000 Acre Complex Stewardship(Private = Gray, Federal = Yellow, State = Blue, Tribal = Brown)

Colony Size Class Distribution

7 km Complex Size Class Distribution

3 km Complex Size Class Distribution

1.5 km Complex Size Class Distribution

Summary byFWP Region

Region No. Colonies Total Acres

2 1 77

3 143 12,414

4 525 41,953

5 1,581 110,208

6 1,459 143,458

7 5,184 337,979

Total 8,893* 646,089**Totals are greater than total number of colonies and total acreage because some colonies are split between FWP Regions.

Summary byBLM Field Office

Field Office No. Colonies Total Acres

Billings 1,558 104,801

Butte 109 10,186

Dillon 31 2,164

Lewistown 544 43,933

Malta 1,364 142,534

Miles City 5,268 342,471

Total 8,893* 646,089**Totals are greater than total number of colonies and total acreage because some colonies are split between BLM Office.

Summary byTribal Reservation

Reservation No. Colonies Total Acres

Blackfeet 4 193

Crow 450 30,431

Fort Belknap 273 34,729

Fort Peck 17 1,194

N. Cheyenne 166 9,987

Rocky Boys 1 59

Total 911 76,592

Summary byUSFS District

Forest/District No. Colonies Total Acres

Custer / Ashland 98 3,406

Custer / Beartooth 5 188

Helena / Helena 1 77

Total 104 3,671

Summary by CountyCounty No. Colonies Sum of Acres

Big Horn 569 35291

Blaine 319 35503Broadwater 24 2076Carbon 167 5695Carter 83 8613Cascade 29 2493Chouteau 317 31794Custer 1709 89201Daniels 9 210Dawson 36 1217Fallon 19 1152Fergus 135 10794Gallatin 39 3030Garfield 409 30948Glacier 2 47Golden Valley 59 4197Hill 11 907Jefferson 15 1502Judith Basin 10 1589Lewis & Clark 33 4028Liberty 18 1399Madison 31 2165

County No. Colonies Sum of AcresMcCone 110 5113Meagher 23 2558Musselshell 228 22565Park 14 633Petroleum 175 14056Phillips 749 74193Pondera 11 719Powder River 621 38636Prairie 141 8959Richland 32 2178Roosevelt 25 1275Rosebud 1833 136363Sheridan 20 921Stillwater 144 10300Sweet Grass 21 1515Teton 29 2970Toole 8 709Treasure 141 10949Valley 81 6369Wheatland 66 4223Wibaux 3 99Yellowstone 450 26936

*Some colonies are split between counties so sum of colonies and acreages here will exceed total no. & acreage of colonies.

Isolated Colony Near Grey Cliff SE of Big TimberConservation Issues? Opportunities for Research?

Suggested Uses and Future Work• Do not use acreage values from this assessment• Evidence of recent activity ≠ presence• Use with previous points and polygons when possible• Use polygonal layer of colonies in environmental reviews

and broad scale planning, but note the need to evaluate individual polygons on the ground

• Not useful for White-tailed Prairie Dog colonies• Ground truth random selection of previously unconfirmed

colonies to evaluate overall mapping accuracy (2005 and 2009)

• Ground truth unconfirmed colonies outside current known range

• Ground truth unconfirmed colonies on upper Missouri upstream of Craig and those that are very isolated

• Ground truth and update mapping for portions of large complexes (use 2009 NAIP and GPS info)