Observational Research Methods - population monitoring Dr. Christopher DePerno MS Students - Stan Hutchens, Aimee’ Rock

1. Observational Research Methods - population monitoringDr. Christopher DePernoMS Students - Stan Hutchens, Aimee’ Rockhill, Mark Sandfoss

2. Population estimation • Index and Census methods for population estimation were first described by Wight (1938). • These methods remain an important cornerstone of wildlife management.

3. Index vs Census • Index – An estimate of the population. • Census – A complete count of an entire population. • Very rare and difficult to accomplish in wildlife research.

4. Why estimate populations? • Abundance is a currency which success is measured • Rare or endangered species • Overabundant • Also, even if other variables are ‘more’ important (e.g., habitat) population size is related.

5. Monitoring programs • Wildlife management often requires a population monitoring program • Three important reasons for estimating populations • State-dependent management decisions • Adaptive management – how is it working? • Model evaluation • Importantly, monitoring must be done continuously.

6. Important Variables • Mortality • Reproduction • Immigration • Emigration • Interaction – Population size, above variables, environmental conditions, management decisions and actions

7. Definitions • Population – group of ‘something’ that occupies a certain area at a certain time defined by the researchers. • Abundance – refers to the number of individual animals (absolute abundance). • Relative Abundance – ratio of abundances • Species at 2 points in time • 2 species at a point in time

8. Definitions • Population Density – individuals/unit area • Abundance and area are related to density • Abundance is usually easier to measure • Relative Density – ratio of population density between 2 areas. • Population Estimate - ~ of the ‘true’ population calculated from a sampled population.

9. Definitions • Population Closure – Absence of births, deaths, immigration, and emigration over a specified period. • Demographic and geographic • Open Population • Population Index – a statistic (calculated population) used to compare populations at different times or locations.

10. Definitions • Observability – probability that a member of a sampled population is detected. • Sightability • Detection Probability • Detectability • Catchability • Model – an abstraction of reality that contains relevant variables for a specific purpose/question. (many types)

11. Estimates of AbundanceComplete counts • Complete counts (census) • Drive counts • Total mapping • Territory mapping • Point counts • Thermal counts • Radar • Aerial photography • Population reconstruction

12. Incomplete counts • Double sampling (ground and air) • Marked subsample • Aerial (multiple observers) • Ground (Multiple observers) • Distance sampling • Time of detection • Observability models

13. Capture counts • Removal (catch/unit effort) • Capture-Mark-Recapture (Lincoln-Peterson)

14. Birds • Point counts • Birdfeeder counts • Breeding bird survey • Area counts • Nesting counts • Coastal Beach shorebird counts • Radar • Aerial Photography • Mist netting

15. Mammals • Camera surveys • Track surveys • Spotlighting • Aerial counts • Fecal surveys • Dead animal surveys • Harvest Data • CPUE

16. Inventory and Assessment of the Reptile and Amphibian Community of Bull Neck Swamp, Washington County, North Carolina Stan Hutchens Master’s Student

17. Reptile and amphibian populations declining globally • Urbanization, acidification, global warming, disease, etc… • Inventory and monitoring essential • Land-use interests for BNS initiated research on these taxa www1.istockphoto.com news.bbc.co.uk www.saveafrog.org

18. Research Objectives • Estimate species richness and abundance of reptiles and amphibians • Compare capture techniques • Compare taxa presence across habitats • Provide monitoring recommendations • Provide educational and extension opportunities

19. Bull Neck Swamp Research Forest • Research, hunting, forest management • 2,428 ha pocosin wetland • - Owned by NC State University • - Managed by the Fisheries and Wildlife Sciences Program http://cnr.ncsu.edu/for/dept/bullneck.html

20. How? • May – August, 2005 and 2006 • Employed 11 different capture techniques • Variable distributions • “Taxon overlap” design • EstimateS v. 8.0 Analyses • Species richness (S) • Similarity indices (JSI)

21. How? • Techniques include • Primary • Drift fence arrays • Visual encounter • Coverboards • Secondary • Road searches • PVC piping grids • Line transects • Auditory • Tertiary • Opportunistic • Aquatic Funnel • Basking traps • Crayfish traps

22. Results • Primary detected 13 species • Secondary – 18 species • Tertiary - 24 species • All sampling methodologies combined captured 33 species. • More unique species were captured by tertiary techniques than primary or secondary methodologies. • Costs for primary techniques were much higher than for secondary and tertiary methodologies.

23. Results

24. Using bobcat (Lynx rufus) as an indicator species in developing a management plan for Bull Neck Swamp Research Forest, N.C. Aimeé Rockhill, Ph.D. student Advisor: Dr. Christopher S. DePerno

25. Bull Neck Swamp Research Forest • Research, hunting, forest management • - Owned by NC State University • Managed by the Fisheries and Wildlife Sciences Program • 2,428 ha pocosin wetland • Use bobcat as an umbrella species http://cnr.ncsu.edu/for/dept/bullneck.html

26. Objectives • Determine the most efficient survey technique for estimating abundances and distributions of mammals that can be used in Pocosin wetland habitats of North Carolina. • Develop a model of habitat use by bobcats in Pocosin wetlands. • Using GPS collars, determine seasonal use by bobcats of areas with different land covers in a Pocosin wetland. • Using data for bobcats at Bull Neck Swamp, test my model and other pre-existing, landscape level models. • Develop a global database of bobcat tracks to that can be used for non-invasive population monitoring with the cooperation of Wildtrack (wildtrack.org) and the SAS Institute.

27. 1. Determine the most efficient survey technique for estimating abundances and distributions of mammals that can be used in Pocosin wetland habitats of North Carolina. • Opportunistic • Take out • Predator calling • Take out • Spotlight Survey • Take out • Camera Monitoring • Scent Station • Wildtrack Analysis Photos provided by: southeasternoutdoors.com dnrstate.md.us texashuntfish.com

28. Scent Station, Camera Monitoring, and Wildtrack • 18 Scent Stations • baited with bobcat • urine and sardines • Tracks and images used • for Population Estimation • 9 scent stations equipped • with cameras

29. Spot Patterns

30. 2. Develop a model of habitat use by bobcats in Pocosin wetlands. • Similar to Fecske (2003) • High resolution aerial photography, color-infrared and panchromatic • supervised classification • Ground truth • Construct model variables by recoding database with suitability ranks • Connect points with similar values to form contours

31. 300 points per season 30 random points per bobcat 30 GPS points per bobcat

32. 3. Using GPS collars, determine seasonal use by bobcats of areas with different land covers in a Pocosin wetland. • Average Euclidean distance • Fixed kernel, LCV • (Home Range Extension) • Compare between sexes • Compare between seasons • Summer, Winter or • Summer (kitten-rearing) • fall (dispersal) • winter (breeding, gestation, dispersal) • Spring (denning)

33. 4. Using data for bobcats at Bull Neck Swamp, test the model and other pre-existing, landscape level models. • Lancia, Hazel, Miller, Hair (1982) • Agriculture, Pocosin, Bottomland hardwood, Upland hardwood, Mixed pine hardwood, Mature pine, Young pine plantation, Tidal freshwater marsh, road • Life requisite suitability indices (LRSI’s) – could increase HQI • Roberts • Forest, Shrub, Open dunes, Salt marsh, Sand, Open/altered, Developed, Roads, water • Added a reproduction component (habitat type and patch size, cover component)

34. 5. Develop a global database of bobcat tracks to that can be used for non-invasive population monitoring with the cooperation of Wildtrack • Conservators Center Inc. • 84 zoos with bobcats in the U.S. • 20 from DC to FL • 8 with claws in FL • Cage limitations • 12 more to find • connections?

35. Population Modeling of Feral Pigs and White-tailed Deer at Howell Woods, NC. North Carolina State University Fisheries and Wildlife Sciences Mark Sandfoss, M.S. Student Advisors: DePerno/Lancia

36. Project Background Howell Woods is owned by Johnston County Community College Educational and Recreational Facility 2,800 acres composed primarily of bottomland hardwoods

37. Species of Interest • Texas feral hog population at 4 million animals (Clay 2007). • The United States Animal Health Association’s committee on Pseudorabies ranked Johnston County number 6 . • Johnston County: 74 hog farms containing 190,000 hogs (United States Animal Health Association 2005). • NC is the Nation’s 2nd ranked pork producer, a 2 billion dollar industry (North Carolina Department of Agriculture and Consumer Services 2005).

38. Objectives Estimate deer and feral hog population sizes, trends, and harvest impacts. Create a population model. Create user-friendly CPUE model in JMP. Determine temporal and spatial movements of feral hogs and deer and harvest impacts upon movements. Test feral hog population for disease and transmission possibility with local livestock (Brucellosis, Psuedorabies, Trichinella, etc.).

39. CPUE • Catch per Unit Effort • Harvest Data • Hunter Sight Data • Camera Data • Hunter Survey • Animals Sighted • Animals Harvested • Hours Hunted

40. Essentially • Wildlife Management is based on • Habitat management • Harvest • Only effective if they influence the population in the manner intended • To know if these management techniques work, managers must understand the population.

41. Problems • All method have problems with the estimating the detection probability • Complete counts – problems with technique • Incomplete counts – problems with technique and detection probability

42. Problems • Observer bias • Time of day • Season • Technique • Weather • Randomness/non-randomness • Capture bias

44. Statistical Definitions • Frequency of Occurrence – units (traps or plots) that measure a particular attribute. • Expected Value – average value if repeated many times. • Accuracy – measure of how close an estimate is to the true quantity. • Bias – the difference between expected value and the true quantity. • Precision – variation in estimates obtained from repeated samples.