Using simulation to improve wildlife surveys: wintering mallards in Mississippi, USA
Aaron T. Pearse A C , Kenneth J. Reinecke B , Stephen J. Dinsmore A and Richard M. Kaminski AA Department of Wildlife and Fisheries, Box 9690, Mississippi State University, Mississippi State, MS 39762, USA.
B United States Geological Survey, Patuxent Wildlife Research Center, 2524 South Frontage Road, Suite C, Vicksburg, MS 39180, USA.
C Corresponding author. Email: apearse@usgs.gov
Wildlife Research 36(4) 279-288 https://doi.org/10.1071/WR08082
Submitted: 28 May 2008 Accepted: 23 December 2008 Published: 1 June 2009
Abstract
Wildlife conservation plans generally require reliable data about population abundance and density. Aerial surveys often can provide these data; however, associated costs necessitate designing and conducting surveys efficiently. We developed methods to simulate population distributions of mallards (Anas platyrhynchos) wintering in western Mississippi, USA, by combining bird observations from three previous strip-transect surveys and habitat data from three sets of satellite images representing conditions when surveys were conducted. For each simulated population distribution, we compared 12 primary survey designs and two secondary design options by using coefficients of variation (CV) of population indices as the primary criterion for assessing survey performance. In all, 3 of the 12 primary designs provided the best precision (CV ≤ 11.7%) and performed equally well (diff ≤ 0.6%). Features of the designs that provided the largest gains in precision were optimal allocation of sample effort among strata and configuring the study area into five rather than four strata, to more precisely estimate mallard indices in areas of consistently high density. Of the two secondary design options, we found including a second observer to double the size of strip transects increased precision or decreased costs, whereas ratio estimation using auxiliary habitat data from satellite images did not increase precision appreciably. We recommend future surveys of mallard populations in our study area use the strata we developed, optimally allocate samples among strata, employ PPS or EPS sampling, and include two observers when qualified staff are available. More generally, the methods we developed to simulate population distributions from prior survey data provide a cost-effective method to assess performance of alternative wildlife surveys critical to informing management decisions, and could be extended to account for effects of detectability on estimates of true abundance.
Acknowledgements
The Mississippi Department of Wildlife, Fisheries and Parks was our primary sponsor and provided funding from the state’s migratory bird stamp program. Other sponsors providing financial and logistical support included the Anderson-Tully Co.; Delta Wildlife; Forest and Wildlife Research Center, Mississippi State University; Ducks Unlimited, Inc., Southern Regional Office; Jack H. Berryman Institute; Mississippi Cooperative Fish and Wildlife Research Unit (Research Work Order 74); USA Department of Agriculture, Animal and Plant Health Inspection Service – Wildlife Services – National Wildlife Research Center; and the Science Support Program, jointly administered by the USA Fish and Wildlife Service and USA Geological Survey. We thank A. Nygren for expert pilot services and S. C. Barras, L. W. Burger, J. S. Hatfield, B. D. Leopold, A. Taylor, K. A. Wilkins, and two anonymous referees for valuable comments on previous versions of this manuscript, which was approved for publication as Mississippi State University – Forest and Wildlife Research Center Journal Article WF-272.
Bart, J. (2005). Monitoring the abundance of bird populations. The Auk 122, 15–25.
| Crossref | GoogleScholarGoogle Scholar |
Caughley, G. (1977b). Sampling in aerial survey. Journal of Wildlife Management 41, 605–615.
| Crossref | GoogleScholarGoogle Scholar |
Conroy, M. J. , Goldsberry, J. R. , Hines, J. E. , and Stotts, D. B. (1988). Evaluation of aerial transect surveys for wintering American black ducks. Journal of Wildlife Management 52, 694–703.
| Crossref | GoogleScholarGoogle Scholar |
Greer, D. M. , Dugger, B. D. , Reinecke, K. J. , and Petrie, M. J. (2009). Depletion of rice as food of waterfowl wintering in the Mississippi Alluvial Valley. Journal of Wildlife Management 73,in press.
Madsen, J. (1998). Experimental refuges for migratory waterfowl in Danish wetlands. II. Tests of hunting disturbance effects. Journal of Applied Ecology 35, 398–417.
| Crossref | GoogleScholarGoogle Scholar |
McWilliams, S. R. , Dunn, J. P. , and Raveling, D. G. (1994). Predator–prey interactions between eagles and cackling Canada and Ross’ geese during winter in California. Wilson Bulletin 106, 272–288.
Nichols, J. D. , and Williams, B. K. (2006). Monitoring for conservation. Trends in Ecology & Evolution 21, 668–673.
| Crossref | GoogleScholarGoogle Scholar |
Pearse, A. T. , Dorr, B. S. , Dinsmore, S. J. , and Kaminski, R. M. (2007). Comparison of sampling strategies to estimate abundance of double-crested cormorants in western Mississippi. Human–Wildlife Conflicts 1, 27–34.
Poysa, H. (1987). Costs and benefits of group foraging in the teal (Anas crecca). Behaviour 103, 123–140.
| Crossref | GoogleScholarGoogle Scholar |
Reinecke, K. J. , Brown, M. W. , and Nassar, J. R. (1992). Evaluation of aerial transects for counting wintering mallards. Journal of Wildlife Management 56, 515–525.
| Crossref | GoogleScholarGoogle Scholar |
Smith, S. J. , and Gavaris, S. (1993). Improving the precision of abundance estimates of eastern Scotian Shelf Atlantic cod from bottom trawl surveys. North American Journal of Fisheries Management 13, 35–47.
| Crossref | GoogleScholarGoogle Scholar |
Verma, V. , Scott, C. , and O’Muircheartaigh, C. (1980). Sample designs and sampling errors for the world fertility survey. Journal of the Royal Statistical Society. Series A (General) 143, 431–473.
| Crossref | GoogleScholarGoogle Scholar |
Ward, D. H. , Reed, A. , Sedinger, J. S. , Black, J. M. , Derksen, D. V. , and Castelli, P. M. (2005). North American brant: effects of changes in habitat and climate on population dynamics. Global Change Biology 11, 869–880.
| Crossref | GoogleScholarGoogle Scholar |
Wielgus, R. B. (2002). Minimum viable population and reserve sizes for naturally regulated grizzly bears in British Columbia. Biological Conservation 106, 381–388.
| Crossref | GoogleScholarGoogle Scholar |
Williams, B. K. , Koneff, M. D. , and Smith, D. A. (1999). Evaluation of waterfowl conservation under the North American waterfowl management plan. Journal of Wildlife Management 63, 417–440.
| Crossref | GoogleScholarGoogle Scholar |
Zielinski, W. J. , and Stauffer, H. B. (1996). Monitoring Martes populations in California: survey design and power analysis. Ecological Applications 6, 1254–1267.
| Crossref | GoogleScholarGoogle Scholar |