Introduction. Study objectives. General Methods Study Area. Wild Turkey Survival and Habitat Use in Central Mississippi

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1 Introduction Wild Turkey Survival and Habitat Use in Central Mississippi Brad Holder Department of Wildlife and Fisheries Mississippi State University The Eastern Wild Turkey (Meleagris gallopavo silvestris) is economically and ecologically important Current distributions are similar to pre-colonial ranges after drastic population decreases during the late 1800s and early 1900s As landscapes change, healthy populations are dependent upon continued investigations into life history and habitat parameters Study objectives General Methods Study Area 1) Model the daily survival of Wild Turkeys in Central Mississippi. Determine effects of sex, age, season, year, and reproductive status. 2) Measure habitat use by Wild Turkey broods and non-brood hens. Determine habitat use during pre- and postnesting periods and their relationship to managed openings. Malmaison Wildlife Management Area (MWMA) ha of loess hills and alluvial floodplain Hardwoods dominate landscape ~ 60, 1-3 ha managed openings [_ Lefllore Co. Grenada Co. Carroll Co. 1

2 General Methods - Capture Capture season was late winter and early spring Used both rocket and cannon nets Jakes and hens Age and sex were recorded General Methods, cont. 90g transmitters with active and mortality signals Bird censored if mortality occurred during a 2 week censorship period (Seiss 1989) General Methods Cont d Hens and jakes were monitored 3 times weekly from early spring through late summer (February to August) in 2003 and 2004 Birds were checked bi-weekly during fall and winter Justification: Estimate future population growth Investigate factors influencing survival Management Survival Study 2

3 Factors of interest Sex (Burk 1989, Little et al. 1990) Age (Vander Haegen et al. 1988, Hubbard et al. 1999) Year (Wright et al. 1996, Lowery 1999) Season (Seiss 1989,Godwin 1991, Jones 2001) Reproductive status (Miller 1997) Assumptions The duration of the study was 700 days 19 September 2002 through 18 August 2004 Juveniles became adults March 1 of the following year. I assumed incubation lasted 28 days for the reproductive status covariate. Year and Seasonal Intervals Interval Date 2003 Jan. 1 Dec Jan. 1 Aug. 18 Spring Mar. 1 May 31 Summer Jun. 1 Aug. 31 Fall/Winter* Sep. 1 Feb. 29 Survival Analysis Program MARK nest survival model was used to estimate survival rates. Date of loss was only in an interval Used AIC model selection to evaluate competing models Model variables were chosen based on previously established relationships to annual survival and natural history. *Seasons were combined because of similar rates reported between the two (Palmer et al. 1993, Wright et al. 1996) 3

4 Results Twenty-one adult hens, 17 juvenile hens, 14 jakes, and 11 adult gobblers were used for analysis. 29 mortalities: 19 due to predation (65%) 7 mature gobblers harvested (21%) 2 illegal harvests (7%) 2 unknowns (7%) Model Selection Results Model AICc Delta AICc AICc Wt. k Dev. Group (age * sex) season (spr, sum, fall/winter) season (spr + all else) Sex + 2season Spr/sum + fall/winter Sex + 3season Year Constant Sex Reproductive status Beta Estimates Best model (age*sex interaction) Compared to adult females, adult males had lower survival (β= -1.86, 95% CI -2.73, -0.99) Juvenile male (β= 0.70, 95% CI -0.43, 1.83) and juvenile female (β= -0.12, 95% CI -1.05, 0.81) survival did not differ from that of adult females. Daily Surviv val Rate Survival Estimates Juvenile 1Males Adult 2Males Juvenile 3Females Adult Females 4 5 Group 4

5 Group Season Rate 95% CI JM* AM* JF AF Seasonal Survival Rates a Fall/Winter Spring Summer Fall/Winter Spring S Fall/Winter Spring Summer Fall/Winter Spring Summer Summer asurvival rates were derived from a post hoc group+3season model. *Survival rates were calculated from one year of data Conclusions Jake survival was highest among groups and similar to that reported by Wieme (2001). Spring season survival for all groups was similar to other studies (Godwin 1991, Wright et al. 1996). Fall and winter survival was higher than other rates reported (Seiss 1989, Chamberlain 1995). Conclusions, cont. A small sample size: Prevented a fit of more complex models. Limits inferences Future Research: Continued monitoring of jake survival Investigate habitat specific survival Investigate relationships between body condition and survival Habitat Use Study Justification: Determine how habitat use changes as landscapes change Evaluate habitat management practices 5

6 Methods - Location Hens (n = 24) located 3 times weekly from 15 March to 12 August in 2004 A minimum of 3 bearings taken from telemetry stations (n = 96) towards hen Location estimates generated in Program Locate III (V3.5; Nams 2005) Methods Habitat Habitats within hen 95% kernel home ranges were considered available (3 rd order habitat selection level; Johnson 1980) Digitized a stand-level habitat coverage map in ArcMap 8.3 using aerial photo-interpretation Hens were split into delta and hills sample populations and brood and non-brood groups Habitat Types on MWMA Assumptions Agricultural fields Bottomland hardwood stands Edge Managed openings Old fields Pine plantations Upland hardwood stands Hen locations were independent Habitats were equally available (Johnson 1980) Reproductive period was divided into prenest (15 March-15 May) and post-nest (16 May-8 August) periods (Hurst 1988) 6

7 Habitat Use Analysis Euclidean distance analysis was used to assess nonrandom habitat use Robust against telemetry error Detect use of edge habitat Chi-square goodness of fit analysis was used to evaluate habitat use among groups Bonferroni confidence intervals were used to determine how habitats were used Results Location data from 11 delta and 13 hills section hens were used for analysis. Of those 6 were brood hens Mean telemetry system error was 8 ± 2.5 degrees Euclidean Distance Results Nonrandom habitat use among delta (Wilk s Lambda = 0.11, F6,5 = 6.95, P = 0.03) and hills (Wilk s Lambda = 0.16, F7,6 = 4.43, P = 0.04) section hens The following habitats were used more than expected (P < 0.05) 05) and are ranked in order of preference Delta Section Hills Section Bottomland hardwoods (P < 0.01) Pine plantation (P < 0.01) Managed openings (P < 0.01) Managed openings (P = 0.02) Edge (P = 0.01) Old fields (P = 0.02) Period Habitat Use by Delta Hens Habitat Brood Hen Non-Brood Hen Pre Post Pre Post Agricultural fields N/A (-)* R** Bottomland hardwoods N/A (+) R (+) Edge N/A R Managed openings N/A R (+) Old fields N/A (-) R (-) *Probability of disproportionate use < (+) = used more than expected and (-) = used less than expected (Byers et al. 1984). **Random habitat use (P 0.05). 7

8 Period Habitat Use by Hills Hens Habitat Brood Hens Non-Brood Hens Pre Post Pre Post Agricultural fields R** (-)* (-) Bottomland hardwoods R (+) (+) (-) Edge R Managed openings R Old fields R (+) Pine plantations R (+) (+) Upland hardwoods R (-) Interpretation of results Small samples prohibited use of robust analysis techniques Detection ti deficiencies i i associated with Neu et al. (1974) method (i.e., telemetry error, patch size and geometry) (White and Garrot 1990, Conner and Plowman 2001) *Probability of disproportionate use < (+) = used more than expected and (-) = used less than expected (Byers et al. 1984). **Random habitat use (P 0.05). Conclusions Bottomland hardwood stands appeared to be important habitats for broods (Phalen 1986, Wiliams et al. 1997) Managed openings were important due to the foraging areas they provided (Chamberlain 1995) Recently thinned pine plantations may have been preferred due to understory development (Stys 1992, Smith et al. 1990). Conclusions, cont. Vegetation structure and density of selected old fields were different than that of other old fields across the study area and facilitated use by young broods Conditions in upland hardwood stands may have contributed to decreased use by brood and non-brood hens during both periods (Pack et al. 1980) 8

9 Future research Determine brood period habitat use using Euclidean distance analysis (Phalen 1986). Determine use of managed openings based on management practices, shape and size, and spatial juxtaposition. Management Recommendations Maintain a mixture of stand developmental stages (Miller 1997). Retain stands of mature hardwood with selection cuts made in appropriate areas to release understory. Continue management of wildlife openings by planting and annual mowing. Strip-disking could be implemented to promote herbaceous vegetation (Lafton et al. 2001, Greenfield et al. 2003). Acknowledgements Questions? Dr. Stephen Dinsmore Dr. Burger, Dave Godwin, Dr. Vilella Mississippi Department of Wildlife, Fisheries, and Parks Mississippi State University NWTF Mark Sczyzpinski, Byron Buckley Graduate Students: Sharyn Hood, Theresa Childers, Aaron Pearse, Ivan Llerandi 9