1. Estimating Greater Sage-grouse Juvenile Survival in Utah Utah State University David Dahlgren Terry Messmer David Koons

2. Introduction Info Need

3. Study Area Parker Mountain

4. Methods

5. Methods – Burkepile et al. 2002

6. Methods Hen Behavior

7. Methods Monitoring

8. Methods Veg and Arthropod Sampling

9. Brood Mixing

10. Methods Cause of mortality  Handling  Exposure  Predation Avian/Mammalian  Unknown

11. Methods Modeling  Manly and Schmutz 2001 - JWM Maximum Likelihood Estimation (Version of the Mayfield Estimator) Heterogeneity - D Brood ID No. chicks start No. chicks end Age (days) Start Age (days) End Covariates 8076523Year etc. 8075536Year etc. 8075569Year etc. 80755911Year etc. 807551113Year etc. 807551315Year etc. 807541517Year etc.

12. Methods Modeling Survival  First Age Structure (weeks 1 to 6)  Used to assess covariates  AIC  Second Assess covariates  Temporal  Brood hen characteristics  Vegetation data  Arthropod data

13. Methods Modeling Survival  Assumptions Brood-mixing and right censoring Missing chicks Brood-mixing and missing chicks

14. Methods Modeling Survival  First Covariates Year Brood Type Hen Behavior (restricted data set) Hen Age (restricted data set) Hatch Date

15. Methods Modeling Survival  Second – Vegetation Covariates (restricted data set) Shrub cover and height Grass cover and height Forb cover and height  Third – Arthropod Covariates (2006, restricted data set) Hymenoptera (ants separate), Coleoptera, Lepidoptera, Orthoptera, miscellaneous, and total arthropods

16. Results Sample sizes  Total 2005 n = 89 chicks in 21 broods (mean = 4.24) 2006 n = 61 chicks in 21 broods (mean = 2.91)  Handling Death (2.6%) 2005 n = 3 2006 n = 1  Excluded from the survival analysis

17. Results Sample Sizes  Chick mass Mean = 29.5g (SE = 0.16) Transmitter averaged 5.1% (SE = 0.0003) of chick weight  Hen Behavior 43% Very protective (18/42) 38% Moderately protective (16/42) 19% Non-protective (8/42)

18. Results Sample Sizes  Brood Mixing 21% of marked chicks (31/146) 43% of marked broods (18/42) 45% of mixing events involved >1 chick (9/20) Occurred weeks 1 to 6 70% (14/20) in weeks 2 and 3 Radio-marked hen mortality (n = 2)

19. Results Sample Sizes  Chick Mortality n = 44 documented deaths n = 26 missing (assumed depredated) n = 6 exposure  Predation 91% (64/70)  Unknown 75% (48/64)  Mammalian 12.5% (8/64)  Avian 12.5% (8/64)

20. Results ModelKAICwiwi Age Specific Models (no covariates) age = (week1)+(week2)+(week3)+(week4)+(weeks5-6)6345.890.000.99973 age = (weeks1-2)+(weeks3-4)+(weeks5-6)4362.4716.580.00025 age = (week1)+(week2)+(week3)+(weeks4-6)5368.9523.060.00000 age = (weeks1-2)+(weeks3-6)3372.6726.780.00000 age = (week1)+(week2)+(weeks3-6)4374.6428.75 0.00000 age = (week1)+(weeks2-6)3398.4052.51 0.00000 age = (weeks1-2)+(weeks4-6)3400.4854.59 0.00000 age = (weeks 1-6)2408.5262.63 0.00000 Covariate Models age* + brood type (regular or mixed)7253.600.000.99999 age* + hen age (yearling or adult)7279.4225.820.00003 age* + year (2005 or 2006)7332.2678.660.00000 age* + hen behavior (protectiveness)8335.0781.470.00000 age* + hatch date (Julian days)7343.0789.470.00000 First – Age parameterization : AIC difference between a model (i.e., model i) and the best performing model (i.e., model with the lowest AIC among the set of models examined). wi: Akaike model weight. * The best model of age = (week1) + (week2) + (week3) + (week4) + (weeks5-6) Second – Temporal and hen characteristics

21. Results ModelKAICwiwi Age Specific Models (no covariates) age = (week1)+(week2)+(week3)+(week4)+(weeks5-6)6345.890.000.99973 First – Age parameterization

22. Results ModelKAIC wiwi Covariate Models age* + brood type (regular or mixed)7253.600.000.99999 Second – Temporal and hen characteristics

23. Results Mean Survival to 42 days = 0.41 (SE =0.046) Chick Survival in Regular broods = 0.38 Chick Survival in Mixed broods = 0.61

24. Results Heterogeneity (D)  Chicks/brood = 3.5  For best model D = 1.10 (SE = 0.22)

25. Results ModelKAIC wiwi age* (NULL)6-19.480.000.99999 Vegetation Covariates  Null Model is best

26. Results ModelKAIC wiwi age* + Ants7-115.160.000.59508 age* (NULL)6-114.390.770.40492 Arthropod Covariates  Entire 42 days  Ant model

27. Results ModelKAIC wiwi age* + Orthoptera5-24.030.000.99999 Arthropod Covariates  Early brood-rearing (day 1-21)  Orthoptera (grasshopper) model Estimates not significant

28. Take Home Predation major cause of chick mortality However, survival was good (mean = 0.41) Our data suggested low dependence among brood mates for sage-grouse chicks Brood-mixing may be important to survival, needs further investigation There is evidence that Arthropods (especially Orthoptera) may aid chick survival, needs further investigation (> sample size)

29. Thanks PARM USU Extension Parker Mtn. Grazing Association Jack H. Berryman Institute UDWR USFS BLM NRCS SITLA Farm Bureau County Commissioners People Technicians Nathan Burkepile Jack Connelly Volunteers

30. Any Questions?