REFERENCES: Shinde, D., L. Pearlstine, L.A. Brandt, F.J. Mazzotti, M.W. Parry, B. Jeffery, and A. LoGalbo. 2014. Alligator

Production Suitability Index Model (GATOR–PSIM v. 2.0): Ecological and Design Documentation. South Florida Natu-

ral Resources Center, Everglades National Park, Homestead, Florida. Ecological Model Report. SFNRC Technical Series

2014:1. 18pp.

Model documentation and code is available at: http://www.cloudacus.com/simglades/alligator.php

ACKNOWLEDGEMENTS: We sincerely thank all contributors that supported the development of this model, includ-

ing those who developed previous alligator habitat suitability models and field researchers for their tireless efforts

collecting and analyzing data. Portions of this work were supported by funding from the U.S. Geological Survey Great-

er Everglades Priority Ecosystems Science Program. Much of the improved understanding of alligator ecology was

made possible by studies funded as part of the Restoration Coordination and Verification (RECOVER) Monitoring and

Assessment Plan (MAP). Thanks are also due to Janice H. Parsons for preparing all the maps.

Courtship & Mating Index Breeding Potential Index Habitat Index Nest Building Index Nest Flooding Index Annual Alligator Breeding Cycle

Stage Period

Breeding Potential (female

growth & survival) April i-1 16—April i 15

Courtship and Mating April i 16—May i 31

Egg Development May i 16—June i 30

Nest Building June i15—July i 15

Egg Incubation July i 01—August i 31

i-1 refers to previous year and i refers to current year

0.0

0.2

0.4

0.6

0.8

1.0

0 10 20 30 40 50 60 70 80 90 100

PI(

H)

% Habitat Subcells (marsh + marsh-upland edge)

0.0

0.2

0.4

0.6

0.8

1.0

0.10 0.13 0.16 0.19 0.22 0.25 0.28

PI(

BP

)

Proportion of wet + dry days

0.0

0.2

0.4

0.6

0.8

1.0

0 10 20 30 40 50 60

PI(

CM

)

Average Water Depth, cm

Without alligator holesWith alligator holes

0.0

0.2

0.4

0.6

0.8

1.0

0 10 20 30 40 50 60P

I(N

B)

Average Water Depth, cm

0.0

0.2

0.4

0.6

0.8

1.0

.00

.01

.02

.03

0 20 40 60 80 100

PI(

NF

)

Fre

qu

en

cy

Mean Clutch Height, cm

71.40 %

The Alligator Production Suitability Index Model (APSI) incorporates concepts from existing alligator habitat suitability models, the literature, and data that have been

collected in the last decade. The model estimates an alligator production suitability index that includes components for habitat assessment and quality, breeding, courtship

and mating, and nesting success (nest building and nest flooding). The major input requirement for the model includes daily continuous surfaces of water depth over the

modeling time period, habitat, locations and height of tree islands, locations of alligator holes, and, optionally, salinity for coastal regions. Users will typically only need to

provide water depths and salinity (if used). Examination of individual components of the index during a year provides insight to any limiting hydrologic conditions that

contribute to a poor overall index, thus inhibiting successful hatchling production. The APSI model can help in optimizing water management to stabilize and improve

alligator populations and has been used to evaluate the effects of alternative Everglades restoration scenarios on habitat suitability for alligator production in the Central

Everglades Planning Project (CEPP).

APSI = {PI(H) * PI(BP) * PI(CM) * PI(NB) * [1-PI(NF)]} 1/5

Alligator Production Suitability Index Model for Restoration Planning and Assessment

Dilip Shinde1, Leonard Pearlstine1, Laura A. Brandt2, Frank J. Mazzotti3, Mark W. Parry1, Brian Jeffery3, and Alicia LoGalbo1

1South Florida Natural Resources Center, National Park Service, Everglades National Park 2U.S. Fish and Wildlife Service

3Fort Lauderdale Research and Education Center, University of Florida

Courtship & Mating Index

Alligator Production Suitability Index

Index0.00 - 0.01

0.01 - 0.10

0.11 - 0.20

0.21 - 0.30

0.31 - 0.40

0.41 - 0.50

0.51 - 0.60

0.61 - 0.70

0.71 - 0.80

0.81 - 0.90

0.91 - 1.00

Courtship & Mating Index Nest Building Index

Breeding Potential Index Alligator Production Suitability Index

Index0.00 - 0.01

0.01 - 0.10

0.11 - 0.20

0.21 - 0.30

0.31 - 0.40

0.41 - 0.50

0.51 - 0.60

0.61 - 0.70

0.71 - 0.80

0.81 - 0.90

0.91 - 1.00

Breeding Potential Index

Nest Building Index

Simulation Results: Year 1983 RSM existing conditions (2012EC) RSM CEPP tentatively selected plan (Alt4R2)