GEER 2010 July 13 Jason Lauritsen Asst. Director Corkscrew Swamp Sanctuary

Transcription

1 Assessment of Wood Stork Foraging Opportunity for Southwest Florida GEER 2010 July 13 Jason Lauritsen Asst. Director Corkscrew Swamp Sanctuary

2 STUDY OBJECTIVE: To improve our understanding of wood stork foraging in order to guide recovery efforts. What factors limit their recovery in SWFL? What does this mean for restoration efforts?

3 Outline Background storks in SWFL Land use changes Study Overview Key findings Relevance to ecosystem restoration

4 Wood Stork Nesting at Corkscrew Nest Numbers Year No. of Nesting Pairs No. of Birds Fledged

5 Historically initiation began in November or December. Since 1978 initiation is typically delayed until January or February

6 A key element of recovery is getting wood storks to nest earlier in the nesting season

7 Nesting Season Comparison B-staff gage Sept 30, B-staff gage Sept. 30, (50yr ave ) No CSS nesting Nest initiation Dec 12 th 1120 nests 2570 fledged Early nesters 2.7ck/nest Late Nesters 2.1ck/nest

8 Wetland Losses within the CFA From pre-development to 2004 Total -44% Short hydroperiod -62% (73-52%)* Wet prairie (6430) -82.2%** Long hydroperiod -19% (34-7%)* Tidal -10% *not all wetland data from the 2004 Land Cover map had hydroperiod data. ** PDVM 73.32sq.mi. down to 13.05sq.mi LULC)

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11 Study Overview Funding awarded through the Critical Ecosystem Studies Initiative (CESI), via the National Park Service Identify & evaluate wood stork foraging habitat near CSS. Document the chronology of wetland availability to foraging by wood storks throughout the nesting season & its influence on nesting success.

12 Study Overview (cont.) Data collected over 2 nesting seasons (did not nest), (successful nesting) Foraging location data Prey sampling (covered in Dr. Liston s s talk) Foraging g events & habitat Mapped using ArcGIS 9.2 SFWMD 2004 Land Use Land Cover & USGS National Hydrography Dataset layers were used.

13 Study Overview (cont.) Data collection (Observation & Sat Tags) Location & use statistics GPS aerial photography Fixed wing aircraft, w/ mm digital camera w/ lens stabilizer Speculative flights & follow flights Supplemented with ground observations Deployment of satellite transmitters on nesting adult storks

14 STUDY AREA 2759 Habitat use pts, GPS tags 730 Foraging g pts, direct observation 7297 Wood storks foraging

15 CORE FORAGING AREA 1540 Habitat use pts, GPS 559 Foraging g pts, direct observation 1865 Wood storks foraging

16 Key Findings Ditches were selected for foraging throughout the nesting season, in both the nesting and nonnesting year. Wet prairies i were selected for early in the nesting season in both nesting and non-nesting years. Freshwater marshes were avoided during the early part of the nesting year, but selected late in both years. Closed canopy forests are used by foraging wood storks. Intensity of use is difficult to assess.

17 Sat Tagged WOST habitat use distribution other 8% Short hydroperiod wetlands 5% Agricultural 16% Short hydroperiod wetlands Long hydroperiod wetlands Hydroperiods undefined by FLUCCS Reservoir Tidal 1% Canal Ditch Long hydroperiod wetlands Canal Ditch 46% Reservoir 2% Agricultural Tidal other 7% Hydroperiods undefined by FLUCCS 15%

18 Value of photo corrections of foraging points Study Year Selection -Avoidance of Primary Habitat Types in the CFA Data Type Non Nesting Nesting Year Visual X 2 = Select: ( ) Observation df=7 N=318 Water, Wetlands P<0.001 Avoid: Agriculture, Urban Built up, Upland Non forested, Upland Forests Nesting Year ( ) Visual Observation X 2 =387.4 df=7 N=240 P<0.001 Select: Water, Wetlands Avoid: Urban Built up, Agriculture,, Upland Non forested Satellite Transmitter Observation X 2 = df=7 N=1540 P<0.001 RAW FLUCCS without photo interp SA_obs CFA_obs SA_SAT CFA_SAT no. of forage locations (non-wetland or water) no. of storks foraging (non-wetland or water) Select: Wetlands, Water Avoid: Urban Built up, Agriculture, Upland Non forested,, Transportation, Communications and Utilities Total forage locations Total storks observed foraging proportion of mis-categorized locations 25.62% 27.37% 16.46% 12.47% proportion of mis-categorized storks 29.63% 31.96%

19 No. of Foraging Events Early 2006 (no nesting) No. of Foraging Events Early 2008 (nesting) 4 13 Row Crops 2140 No. of Foraging Storks Early 2006 (no nesting) Ditches 5120_X Reservoirs Mixed Wetland Hardw oods 6170 Mixed Shrubs Cypress 6210 Cypress Domes Heads Cypress Pine Cabbage Palm Wet Pinelands Hydric Pine Freshw ater Marshes / Graminoid 9 Prairie 17 Marsh Wet Prairies OTHER HABITATS Row Crops 2140 No. of Foraging Storks Early 2008 (nesting) Ditches 5120_XX Reservoirs Mixed Shrubs Row Crops 2140 Reservoirs 5300 Row Crops 2140 Channelized Ditches Waterways, 5120_X Canals 5120 Mixed Wetland Hardw oods 6170 Mixed Shrubs 6172 Wet Melaleuca 6191 Cypress 6210 Ditches 5120_X Lakes 5200 Reservoirs 5300 Mangrove Swamp 6120 Cypress Domes Heads 6215 Mixed Wetland Hardwoods 6170 Cypress Mixed Hardw oods 6216 Mixed Shrubs 6172 Cypress Pine Cabbage Palm 6240 Freshw ater Marshes / Graminoid Prairie Wet Marsh Melaleuca W t P i i 6430 Cypress 6210 Ditches 5120_X Cypress Domes Heads 6215 Reservoirs 5300 Cypress Mixed Hardwoods 6216 Mixed Shrubs Cypress Cypress 2 Domes Heads Wet Pinelands Hydric Pine Freshwater Marshes / 1 Graminoid Prairie Marsh Wet Prairies OTHER HABITATS 71 Cypress Cypress Pine Cabbage 6210 Palm 6240 Wet Wet Pinelands Hydric Pine Pine Wetland Forested Mixed 6300 Wetland Forested Mixed 6300 Freshwater Freshwater Marshes Marshes / Graminoid / Graminoid Prairie Marsh 6410 Prairie Marsh 6410 Wet Prairies 6430 Wet Prairies 6430 OTHER HABITATS OTHER HABITATS

20 No. of Foraging Events Late 2007 (no nesting) No. of Foraging Storks Late 2007 (no nesting) Row Crops 2140 Channelized Waterways, Canals Ditches 5120_X Lakes 5200 Reservoirs 5300 Mangrove Swamp No. of Foraging Events Late 2009 (nesting) Mixed Wetland Hardwoods Mixed Shrubs 6172 Wet Melaleuca 6191 No. of Foraging Storks Late 2009 (nesting) Cypress 6210 Ditches 5120_X 67 Cypress Reservoirs Domes 5300 Heads Cypress Mixed Wetland Hardwoods Hardwoods Cypress Mixed Pine Shrubs Cabbage 6172 Palm 6240 Cypress 6210 Wet Pinelands Hydric Pine 6250 Cypress Domes Heads 6215 Wetland Forested Mixed 6300 Cypress Mixed Hardwoods Freshwater Marshes / Graminoid Freshwater Prairie Marshes Marsh / 6410 Graminoid Prairie Marsh 6410 OTHER Wet HABITATS Prairies 6430 OTHER HABITATS

21 Results of foraging habitat analysis - CFA Non-nesting Nesting No. of foraging events No. of foraging storks No. of foraging events No. of foraging storks LCCODE Early Late Early Late Early Late Early Late Row Crops 2140 N N N N N Channelized Waterways, Canals 5120 N S Ditches 5120_X S S S S S S S S Lakes 5200 S Reservoirs 5300 N N S S N N S S Mangrove Swamp 6120 N A Mixed Wetland Hardwoods 6170 N N A N N N Mixed Shrubs 6172 N N A A N N S A Wet Melaleuca 6191 N Cypress 6210 N N A A N N A A Cypress Domes Heads 6215 N N N N N N S Cypress Mixed Hardwoods 6216 N N N N Cypress Pine Cabbage Palm 6240 N N N Wet Pinelands Hydric Pine 6250 N A A N A A Wetland Forested Mixed 6300 N N S Freshwater Marshes / Graminoid Prairie Marsh 6410 N S N S N S A S Wet Prairies 6430 N N S S S OTHER HABITATS N N A A N N A A X P 8.73E E E E E E E E+00 df N S = selection, A = avoidance, N = neutral. N = very close to S, N = very close to A. S = strongly selected, A= strongly avoided. (blank) = these categories were grouped in the "OTHER HABITATS" category, along with: Marshy Lake 5250, wetland coniferous forests 6200, and saltwater marshes/halophytic herbaceous prairie 6420

22 Foraging in shallow ditches photos taken on wood storks documented foraging in these ditches, in 1 event

23 Foraging in Ag WOST foraging Assessment

24 Use of forested wetlands Corkscrew CFA SWFL Study Area direct observation satellite tagged storks % forested 49% non-forested 221 events 41% in forested % in non-forested 50% forested 50% non-forested 153 events Stork positions in wetlands 3030 positions

25 Forested habitat use

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27 Relevance to Ecosystem Restoration Short hydroperiod wet prairies provided significant foraging value in the nesting season. They play an important role in early nest initiation in SWFL. These should be conservation & restoration priorities.

28 Relevance to Ecosystem Restoration Though they are a cause of wetland loss, shallow, short hydroperiod ditches are highly utilized & provide storks significant foraging value. Greater attention should be paid to tracking losses of shallow ditches via development. Impacts to shallow ditches should be mitigated ii di in wet prairie ii habitat types.

29 Special Thanks to: CESI Sonny Bass (NPS) Ed Carlson (Audubon) Shawn Liston (Audubon) Mike Knight (Audubon) Mike Bush (Audubon) Shawn Homoky (Beaver Aviation) Larry Bryan (SREL) David Ceilley (FGCU) Rena Borkhataria (SFWMD) Ann Marie Lauritsen (USFWS) Mike Duever (SFWMD)