COORDINATED SPRING SURVEY OF 

MID-CONTINENT SANDHILL CRANES 

2005
 2005 

 COORDINATED SPRING SURVEY OF MID-CONTINENT SANDHILL CRANES 

2005 TOTAL: 530,600 

2005 AERIAL TRANSECT: 491,900 

THREE-YEAR AVERAGE (2003-05): 422,100 

SURVEY DATES: 5 - 25 March 2005 

SURVEY PERSONNEL: 

Aerial Survey

 Observer/pilot: John Solberg, USFWS, DMBM, Bismarck, ND 

 Observer: Jeff Drahota, USFWS, Rainwater Basin WMD, Kearney, NE 

 Photographer: Rich Walters, NGPC, Kearney, NE 

Ground Surveys (State Coordinators) 

 North Dakota: Mike Szymanski, NDGFD, Bismarck, ND 

 South Dakota: Spencer Vaa, SDGFP, Brookings, SD 

 Nebraska: Mark Vrtiska, NGPC, Lincoln, NE 

 Kansas: Helen Hands, KDWP, Great Bend, KS 

 Texas: Jay Roberson, TPWD, Austin, TX 

ABSTRACT: The aerial transect portion of the coordinated spring survey of mid-continent sandhill 

cranes was conducted on 23 March in Nebraska’s Platte and North Platte River valleys. The 2005 

photo corrected aerial estimate was 491,900 birds. Outside the traditional aerial transect portion, 

observers utilized both ground and air coverage during the period 5 – 25 March. From this region, 

observers in the Official Survey Area (OSA) of Nebraska, Kansas, and Texas reported an additional 

38,700 cranes. The 2005 total estimate (530,600) increased 18% since 2004 and is the fourth highest 

in twenty-four years of comparable figures. The current three-year average (2003 - 2005), from 

photo corrected aerial transects only, is 422,100. 

 
METHODS: The annual target date for the coordinated survey is the 4th Tuesday of March. Survey 

coverage in 2005 was similar to 2004 and included changes adopted by the Central Management 

Unit Technical Committee (CMU) in 1985. The “traditional” aerial portion of the survey utilizes an 

ocular transect design with a sampling rate of approximately twenty-five percent. Sub-sampling 

crane flocks, using 35 mm oblique photography, allows determination of observer specific 

estimation correction factors which are applied to estimates from the aerial transects. Efforts outside 

the region of the traditional aerial transects are directed by state coordinators. Using a combination 

of ground and aerial coverage, these efforts focus in areas of traditional crane use/occurrence. 

Observations recorded outside the aerial transect region are not photo corrected. Specific details 

regarding personnel, photography, habitat, and weather conditions are on file in the Bismarck office 

of the USFWS. 

RESULTS: The aerial transect component of the 2005 survey was conducted on 3/23, one day later 

than scheduled (weather delay). Concurrently, USGS field researchers reported that 90% (38 of 42) 

of their VHF radio marked cranes were present in the Platte River Valley (D. A. Brandt, USGS, 

pers. comm.). The 2005 total estimate of mid-continent sandhill cranes is 530,600 (Table 1), which 

includes 491,900 birds from aerial transects (Tables 2 and 3), and 38,700 cranes from other regions 

in the OSA. Correction factors, applied to aerial estimates, were calculated from photographs of 56 

unique flocks (Drahota 23, Solberg 33). Observer effort in the 2005 survey is presented in Table 4. 

The 2005 index increased 18% from the 2004 figure and is the fourth highest of comparable record 

(24 years). The current three-year average (2003-2005), based on the photo-corrected Nebraska 

aerial portion, is 422,100 (Figure 1) and is within the management range (343,000 - 465,000) 

established by the CMU (Management Guidelines for Mid-Continent Sandhill Cranes, revised 

March 1993). 

Appreciation is expressed to all coordinators, observers, and participants who assisted in the 2005 

survey. Two long time contributors, Dr. Douglas Johnson (Northern Prairie Wildlife Research 

Center, USGS) for his statistical analysis and Mr. John Steiner (Jamestown, ND) for his photo 

processing and interpretation, continued their able assistance and support in completing the final 

report. 

John W. Solberg 

February 2006 

Reference: 

Benning, D. S. and D. H. Johnson. 1987. Recent improvements to sandhill crane surveys in 

Nebraska’s Central Platte Valley. pp 10 – 16 in J. C. Lewis (ed.), Proc. 1985 Crane Workshop, 

Platte River Whooping Crane Habitat Maint. Trust, Grand Island, NE. 
Table 1. Distribution of Sandhill Cranes within the Mid-Continent region during the coordinated spring survey, 1974-2005 (rounded to nearest 100).

Date ND 5 SD 5 NEBRASKA KS TX TOTAL OK 6 NM 6 CO 6 

 Central Platte Valley 1 Other (OSA) of 

w

Ocular trans. Vertical 

Ocular Ocular w/photo photo Ocular 

cruise transect correction transect cruise 

3/24-31/74 0 0 162,600(92%) 4 - - - 9,000 1,900 3,200 - 400 0 0 177,100 

3/25-30/75 0 0 223,600(98%) - - - 2,300 900 Tr - 100 100 500 227,500 3/22-26/76 - 2 0 147,500(97%) - - - 2,800 300 800 - 100 1,000 0 152,500 

3/13-23/77 0 300 173,400(79%) - - - 1,100 1,600 30,700 - 400 12,500 0 220,000 3/20-24/78 - 0 149,800(94%) 188,600(95%) - - 2,200 700 4,900 - 0 2,300 0 159,900 3/20-29/79 0 0 - 203,600(97%) - - 2,600 1,100 0 - 1,500 0 500 - 3/24-4/15/80 Tr 3 - 223,400(95%) 254,400(96%) - - 5,000 4,100 1,400 - 100 500 0 234,500 

3/22-28/81 0 0 - 248,900(86%) - - 8,300 11,200 21,800 - 0 0 200 - 3/22-27/82 0 Tr - 348,000(95%) 417,300(95%) 490,100(96%) 7,100 2,000 7,800 - 0 100 2,800 - 3/25-26/83 0 0 - 306,300(96%) 343,400(97%) - 4,100 200 7,000 - 200 Tr 0 - 3/25-30/84 0 Tr - 222,700(91%) 261,800(93%) - 18,100 900 800 - 1,100 Tr 0 - 3/25-26/85 - - - 378,100(96%) 514,800(97%) - 11,500 3,000 1,200 530,500 - - - - 3/25-26/86 Tr Tr - 317,000(99%) 353,000(99%) - 1,000 200 2,100 356,300 - - - - 3/24-26/87 0 0 - 383,600(100%) 416,100(100%) - 0 Tr 400 416,500 - - - - 3/21-25/88 0 0 - 386,900(98%) 463,500(98%) - 0 0 7,700 471,200 - - - - 3/28-29/89 0 200 - 391,400(100%) 392,000(100%) - 100 1,000 800 393,900 - - - - 3/27-28/90 Tr Tr - 386,000(94%) 412,200(94%) - 11,000 5,200 10,300 438,700 - - - - 3/25-26/91 0 200 - 297,800(100%) 340,600(100%) - 100 800 200 341,700 - - - - 3/19-25/92 200 Tr - 257,700(95%) 406,500(97%) - 12,200 300 1,100 420,100 - - - - 3/23-24/93 0 100 - 253,800(79%) 378,900(85%) - 16,800 37,700 13,500 446,900 - - - - 3/20-22/94 400 0 - 395,500(96%) 477,200(96%) - 14,600 0 0 491,800 - - 2,400 - 3/28-30/95 200 0 - 273,400(88%) 326,200(90%) - 30,400 0 0 356,600 - - 6,700 - 3/25-26/96 0 0 - 318,900(96%) 520,000(98%) - 7,600 0 0 527,600 - - 3,900 - 3/20-26/97 Tr Tr - 350,900(96%) 534,600(97%) - 16,200 100 0 550,900 - - - - 3/24-26/98 0 Tr - 337,200(96%) 530,800(97%) - 13,600 100 0 544,500 - - - - 3/22-25/99 0 500 - 219,800(68%) 284,900(73%) - 3,500 100,000 0 388,400 - - - - 3/10-29/00 100 800 - 484,600(92%) 490,100(92%) - 16,900 26,100 500 533,600 - - - - 3/25-27/01 0 Tr - 387,300(87%) 413,500(88%) - 10,500 42,300 3,500 469,800 - - - - 3/25-27/02 Tr 0 - 309,000(90%) 315,000(90%) - 17,100 15,100 1,200 348,400 5,800 - - - 3/22-27/03 Tr 400 - 300,900(90%) 348,000(91%) - 24,800 4,100 3,800 380,700 - - - - 3/22-25/04 50 600 - 365,400(94%) 426,500(95%) - 17,700 1,200 2,200 447,600 100 - - - 3/5 - 25/05 Tr 500 - 412,300(93%) 491,900(93%) - 27,100 2,900 8,700 530,600 2,600 - - - 

1 Utilizing various survey techniques within Nebraska's Central Platte Valley.2 No survey.3 Less than 50.4 Percent of total M-C population index.5 Crane sightings for North and South Dakota from 1985 and later are noted for over flight monitoring purposes and are not included in totals.6 OK, NM, CO were eliminated from the Official Survey Area in 1985 by the Central Flyway CMU; crane sightings are noted for informational purposes only.
Table 2. Results of ocular transect survey for Mid-Continent Sandhill Cranes in the 

central Platte Valley of Nebraska during the coordinated spring surveys.

 YEAR Population Index Standard Error 

1978 188,582 ± 23,948 (± 12.7%)

1979 203,574 ± 24,968 (± 12.1%)

1980 254,417 ± 51,738 (± 20.3%)

1981 248,882 ± 31,957 (± 12.8%)

1982 347,996 ± 33,353 (± 9.6%)

1983 306,316 ± 21,257 (± 6.9%)

1984 222,710 ± 17,466 (± 7.8%)

1985 378,127 ± 34,230 (± 9.1%)

1986 317,025 ± 32,461 (± 10.2%)

1987 383,581 ± 53,508 (± 13.9%)

1988 386,853 ± 35,775 (± 9.2%)

1989 391,353 ± 44,066 (± 11.2%) 

1990 385,950 ± 40,585 (± 10.5%)

1991 297,831 ± 27,551 (± 9.2%)

1992 257,709 ± 24,551 (± 9.5%)

1993 253,799 ± 29,896 (± 11.2%)

1994 395,543 ± 40,430 (± 10.2%)

1995 273,376 ± 30,316 (± 11.1%)

1996 318,514 ± 36,182 (± 11.3%)

1997 350,932 ± 58,925 (± 16.7%)

1998 337,203 ± 39,505 (± 11.7%)

1999 219,794 ± 32,164 (± 14.6%)

2000 484,585 ± 57,598 (± 11.9%)

2001 387,336 ± 47,679 (± 12.3%)

2002 309,029 ± 34,399 (± 11.1%)

2003 300,918 ± 32,869 (± 10.9%)

2004 365,370 ± 31,001 (± 8.5%)

2005 412,285 ± 32,482 (± 7.8%)
Table 3. Results of ocular transect survey with photo correction fo for Mid-Continent Sandhill Cranes

in the central Platte Valley of Nebraska during the coordinanted spring surveys.

 YEAR Population Index Standard Error 

1982 417,263 ± 42,331 (± 10.1%)

1983 343,378 ± 31,674 (± 9.2%)

1984 261,802 ± 24,198 (± 9.2%)

1985 514,763 ± 49,650 (± 9.6%)

1986 353,040 ± 37,340 (± 10.6%)

1987 416,058 ± 65,588 (± 15.7%)

1988 463,457 ± 53,213 (± 11.4%)

1989 391,995 ± 51,349 (± 13.0%)

1990 412,154 ± 50,496 (± 12.2%)

1991 340,645 ± 33,897 (± 10.0%)

1992 406,457 ± 50,644 (± 12.4%)

1993 378,883 ± 50,454 (± 13.3%) 

1994 477,215 ± 50,910 (± 10.7%)

1995 326,181 ± 35,256 (± 10.8%)

1996 519,984 ± 62,582 (± 12.0%)

1997 534,630 ± 86,889 (± 16.2%)

1998 530,848 ± 79,164 (± 14.9%)

1999 284,858 ± 35,599 (± 12.5%)

2000 490,118 ± 71,754 (± 14.6%)

2001 413,498 ± 64,221 (± 15.5%)

2002 315,044 ± 42,218 (± 13.4%)

2003 348,023 ± 41,263 (± 11.9%)

2004 426,534 ± 43,337 (± 10.2%)

2005 491,915 ± 47,392 (± 9.6%)
Table 4. Coordinated spring Mid-Continent Sandhill Crane survey effort by state - 2005.

State Date Coverage Means Effort Observer Affiliation

Aircraft Ground (Miles) Federal State Volunteer

Air/Gnd.

ND* 17 - 22 March 2005 - 11 - /900 2 10 -

SD* 5 - 22 March 2005 - ? - / ? 12 8 5

NE 22 - 23 March 2005 2 15 1200/1400 3 17 -

KS 21 - 25 March 2005 - 11 - / 300 1 8 2

TX 22 March 2005 - 10 - /1300 3 6 1

Total 2 47 1200/3900 21 49 8

* Monitors for over flights on or prior to scheduled survey date.
Figure 1. Annual and three-year average photo-corrected ocular transect spring populati

indices and population objective thresholds for Mid-Continent sandhill cranes.

200250300350400450500550600

1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 

Year

Sandhill Crane (Thousands)

Annual Index3-Year AvgThresholds