sea turtle nest site selection analysis 2015 nesting

HEATHER LYNN AFFORDADVISER: DR. PATRICK N. HALPIN

Photo courtesy of Ron Wooten

Sea Turtle Nest Site Selection AnalysisFlorida Panhandle

2015 Nesting Season Results

Why do sea turtles nest where they nest?

oCollect multiple variables and data points for analysis

oUnderstand turtle nest distribution

oPredict Site Selection LocationsoDetermine variables relationship to site selection spatially

oTree ClassificationoDetermine variables in terms of importance to site selection

Data collection of nests and important variables

Nesting Population Distribution





oTree ClassificationoDetermine variable importance in terms of site selection

Random Points (0)

Sand OtherThan Beaches

East Pass ‐ EbbShoal

Offshore andStorm

Overwash

Slope ofBathymetry Bathymetry Distance to

High TideDistance to

RoadDistance toUrban Areas Population Elevation

Beaches OtherThan

SwimmingBeaches

Estimate ‐1.92943 ‐0.92846 ‐0.86005 ‐0.42013 ‐0.1543 ‐0.00982 ‐0.00197 ‐0.00035 0.003499 0.581822 2.915048

‐3

‐2

‐1

0

1

2

3

4

ESTIMAT

E OF AS

SOCIAT

ION

CHARACTERISTIC TYPE & SPECIFIC ASSOCIATION

Significant Characteristics and their Associations with Sea Turtle Nest Site Selection : Presence ‐ Random Model

Final Model Equation:

species ~ Distance to High Tide + Distance to Closest Urban Type + Land Cover Type + Distance to Closest Road +

Population Abundance+ Nourishment Source + Elevation + Bathymetry + Slope of Approach

Sea Turtle Site SelectionPrediction

Sea Turtle Site SelectionPrediction Probabilities:Full Area

Selected Probabilities of Sea Turtle Site Selection

Predicted Random Predicted Nest

Observed Random 214 (True Negative) 71 (False Positive)

Observed Nest 8 (False Negative) 277 (True Positive)

Tree Classification

0285/285

0132/5

10/4

011/11

0132/9

08/0

176/262

066/3

1153/276

11/6

13/11

09/6

167/256

08/0

Elevation Slope < 9.16

Closest Artificial Reef=

Closest Artificial Reef=Concrete CulvertsSpecies Concrete Modules

Wetlands = Estuarine and Marine Deepwater

Wetlands =

Distance from Urban>= 90.82

Distance from Urban< 90.82

Land Cover Type =

Seawall Distance < 187.4 m

Seawall Distance>= 187.4 mBeach Width >= 132.7

Beach Width < 132.7

Elevation Slope >= 9.16Elevation Slope >= 9.16

= Land Cover Type

077/14

Medium Density, Fixed Single Family UnitsBeaches other than Swimming BeachesTidal FlatsSwimming BeachMedium Density, Under Construction

No WetlandFreshwater Forested/Shrub WetlandEstuarine and Marine Wetland

Modules Plastic ConesShip SteelBarge SteelSteel Tank TurretsModules Concrete GhettosArmy Tank M‐60Barge Steel & Steel ScrapModules Concrete Walters Limestone UnitsModules Concrete GhettosShip Steel Tug Concrete CulvertsBridge Rubble Concrete

Community Recreational FacilitiesAuto Parking Facilities

Sand Other than BeachesMixed Scrub‐ shrub Wetland

Parks and Zoos

Nesting Locations based on important characteristics

No Wetland

Freshwater Forested/Shrub Wetland

Estuarine and Marine Wetland

Modules Plastic Cones Barge Steel & Steel Scrap

Modules Concrete Ghettos (65)Modules Concrete Walters Limestone Units

Bridge Rubble Concrete Modules Concrete Ghettos (86)Ship Steel 400' Ship Steel Tug 95Barge Steel Concrete CulvertsSteel Tank Turrets Ship SteelModules Concrete Ghettos (80) Army Tank M‐60 # 6

Medium Density, Fixed Single Family UnitsBeaches other than Swimming BeachesTidal FlatsSwimming BeachMedium Density, Under Construction

_________Landcover Type____________________Wetland_________

_______________Artificial Reef_______________

Conclusions Suggestions Considerations

oPopulationo Highest Density = open areas o Natural physical variables are important

oHabitato High tide, land cover, nourishment, and physical

parameterso Urbanization, is it a problem or not

oTreeo Sea turtles are not deterred by urban

landscapes, nest near wetlands (but not always), and appear to travel towards the beach with reef type in mind

o Multiple years

o Consider species

oIncrease research on urbanizationo sea turtle site selection

oNourishment evaluationo Compare nourishment sand sources to

assess more specifics of beach avoidance

oFalse crawl data‐collection trainingo Discussion between regional

stakeholders

Acknowledgments

North Carolina

o Dr. Patrick N. Halpin

o Dr. Dean L. Urban

o William Cioffi & Erin Labrecque

Florida

o Erika Zambello, Marine Economic and Tourist Development Resource Coordinator at Okaloosa County

o Sharon Maxwell, South Walton Turtle Watch

o Sara and George Gray, Emerald Coast Turtle Watch

o Kathleen Gault & Eglin Air Force Base

o Mark Nicholas, Biologist/Collateral FMO of the Gulf Islands National Seashore and National Park Service

Thank you

Nest & Crawl Type Distribution within the Study Site

County Beach Nests False Crawls Total

Escambia Perdido Key (Public & State) 11 N/A 11

Perdido Key (GI) 17 N/A 17

Fort Pickens (GI) 10 N/A 10

Santa Rosa Island (GI) 35 N/A 35

Pensacola Beach 16 N/A 16

Santa Rosa Navarre 4 1 5

Santa Rosa & Okaloosa Eglin 65 36 101

Okaloosa Okaloosa Island 5 3 8

Destin 13 5 18

Walton Walton 64 NA 64

240 45 285

Best Model Equation: species ~ Land Cover Type + Elevation Slope + Wetlands + Distance to Urban Areas + Beach Width + Artificial Reef Type + Distance to Seawall

Variable Type Variable Attributes :

Amount & Range

Observed Nests (1) Random Nests (0)

Land Cover Type 58 Types Medium Density, Fixed Single Family Units

Beaches other than swimming beaches

Tidal Flats

Swimming Beach

Medium Density, Under Construction

Community Recreational Facilities

Auto Parking Facilities

Sand other than Beaches

Mixed Scrub – Shrub Wetland

Parks and Zoos

Elevation Slope 0 ‐ 29.42 >= 9.16 < 9.16

Wetlands 7 Types No Wetland

Freshwater Forested / Shrub Wetland

Estuarine and Marine Wetland

Estuarine and Marine Deepwater

Distance to Urban Areas 0‐3600 < 90.82 >= 90.82

Beach Width 73.08 ‐ 891.40 >= 132.675 < 132.675

Artificial Reef Type 18 Types Module Plastic Cones

Ship Steel

Barge Steel

Steel Tank Turrets

Modules Concrete Ghettos (2 locations)

Army Tank M‐60

Barge Steel & Ship Scrap

Modules Concrete Walters

Limestone Units

Ship Steel Tug

Concrete Culverts

Bridge Rubble Concrete

Concrete Culverts

Special Concrete Modules

Distance to seawall 0 ‐ 12359.80 < 187.395 >=187.39

False Crawls

Best Model Equation : species ~ Distance to High Tide + Total Land Use Type + Wetlands Type + Nourishment Source + Road Type + Grain SizeVariable Factor Description* Estimate Pr(>|z|)

(Intercept) ‐0.09153 0.94473

Distance from

High Tide

0.05806 0.00186

Total Land

Use

Beaches other than swimming

beaches

‐0.6021 0.525061

Communications ‐0.86227 0.629379

Sand other than beaches ‐5.34499 0.023308

Swimming beach 0.427661 0.653654

Ocean 0.114283 0.914584

Wetlands

Type

Estuarine and Marine Deepwater ‐0.97481 0.128424

Nourishment

Source

Offshore 1.527727 0.469761

Inlet 1.403586 0.133982

East Pass Ebb Shoal ‐0.5605 0.727446

Road Type Road or Street, Class 3 ‐0.73884 0.272859

Secondary Route, Class 2, Undivided ‐0.99841 0.5245

Road or Street, Class 3, Divided by

centerline

1.527727 0.469761

Primary Route, Class 1, Divided by

centerline

2.329372 0.043049

Grain Size 0.106144 0.279332

Sand other thanbeaches

Esturine and MarineDeepwater

Distance from HighTide Inlet

Primary Route, Class1, Divided bycenterline

Estimate ‐5.34 ‐0.97 0.06 1.40 2.33

‐6.00

‐5.00

‐4.00

‐3.00

‐2.00

‐1.00

0.00

1.00

2.00

3.00

Estim

ate Of A

ssociatio

n

Characteristic Type and Specific Association

Significant Characteristics and their Association with Sea Turtle Nest Site Selection: Presence ‐ Absence Model

Works CitedFielding, A.H., and J.F. Bell. 1997. A review of methods for the assessment of prediction errors in conservation presence/absence models. Environ. Conservation 24:38‐49.

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Gallaher, A.A (2009), “The Effects of Beach Nourishment on Sea Turtle Nesting Densities in Florida”, [Online]. Available: http://ufdcimages.uflib.ufl.edu/UF/E0/04/10/87/00001/gallaher_a.pdf

Garmestani, A. S., Percival, H. F., Portier, K. M., & Rice, K. G.. (2000). Nest‐Site Selection by the Loggerhead Sea Turtle in Florida's Ten Thousand Islands. Journal of Herpetology, 34(4), 504–510. http://doi.org/10.2307/1565263

Miller JD, Limpus CJ, Godfrey MH (2003) Nest site selection, oviposition, eggs, development, hatching, and emergence of loggerhead turtles. In: Loggerhead Sea Turtles (eds BoltenAB, WitheringtonBE), pp. 125–143. Smithsonian Books, Washington.

Mortimer, J. A. 1995. Factors influencing beach selection by nesting sea turtles. Pages 45–51 in K. A.Bjorndal, editor. Biology and conservation of sea turtles. Smithsonian Institution Press, Washington , D.C. Retreived fromhttp://college.holycross.edu/faculty/kprestwi/chelonia/pubs/3_book_chapters/BeachSelection.pdf

Mosier, A.E. & Witherington B.E. (nd) “Documented Effects of Coastal Armoring Structures on Sea Turtle Nesting Behavior” [online]. Available: http://www.fws.gov/nc‐es/ecoconf/mosier%20paper.pdf

Ruppert T.K. (2008), “Eroding Long‐Term Prospects for Florida’s Beaches:

Florida’s Coastal Management Policy” [Online]. Available: http://biotech.law.lsu.edu/climate/docs/FINAL%20REPORT_8.19.08.pdf

Salmon, Michael. (2003) Artificial night lighting and sea turtles. Florida Atlantic University, USA. Biologist. 50;4. From http://www.science.fau.edu/biology/faculty/Artificial%20Lighting%20as%20a%20Threat.pdf

Urban, D.L. 2003. Habitat Classification Models: Classification and Regression Trees. Duke University, Lab.

Witherington, B. E.. (1992). Behavioral Responses of Nesting Sea Turtles to Artificial Lighting. Herpetologica, 48(1), 31–39. Retrieved from http://www.jstor.org/stable/3892916

Weishampel J.F., D.A. Bagley, L.M. Ehrhart, B.L. Rodenbeck (2003). Spatiotemporal patterns of annual sea turtle nesting behaviors along an East Central Florida beach. Biol. Conserv., 110, 295–303

See Additional Information for variable data sources

sea turtle nest site selection analysis 2015 nesting

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