Elk Surveys: Where Have We Been and Where Do We Want To Go?

1. Elk Surveys: Where Have We Been and Where Do We Want To Go?

2. Where are we and how did we get here? • Aerial elk surveys conducted annually since 1991 • Data collected: • Herd composition data • Total number observed

3. ww Bull/Cow Cow/Calf = Herd Composition

4. Thi Slope of the line Y = -15,075.5 + 7.6x r2 = 0.80, P < 0.001

5. X Y = -2,292.3 + 1.2x r2 = 0.10, P = 0.07 Y = -2,168.2 + 1.1x r2 = 0.45, P = 0.002

6. Y = -3,185.7 + 1.6x r2= 0.46, P = 0.002

7. Y = -22,721.8 + 11.5x r2 = 0.74, P < 0.001

8. Y = 1815.9 + -0.9x r2 = 0.47, P < 0.001 X Y = 1418.8 + -0.7x r2 = 0.13, P = 0.13

9. Limitations of current survey methods • Not designed to produce population or density estimates • Does not provide reliable elk distribution data

10. The next step: Where do we want to go from here? Develop a statistically rigorous survey method that will produce defendable population and density estimates, and distribution data AGFC 2009 Strategic Elk Management Plan Resource Goal, Objective A, Strategy 3; Approved 24 Sept. 2009

11. Estimating abundance is a complex issue • Reliable abundance data are highly prized in wildlife management • Biologists interested in estimating abundance face 2 problems: • Detectability of the animals • Sampling the space the animals occupy

12. Detectability • Abundance estimates are based on counts, which represent unknown fractions of target populations • The central problem of abundance estimation involves estimating how many animals are not being observed

13. Example: elk detectability model

14. Example: elk detectability model

15. Expected Results and Benefits • Reliable population abundance, density, and distribution data will inform harvest and habitat management, et. al. • We will be able to deal intelligently and confidently with questions and concerns from the public about elk management issues