Solar and Topographical Breeding Habitat Preferences of Two Damselflies: Calopteryx

aequabilis and Calopteryx maculata.

By: Chris St. AndreMentor: Dr. Darcy Boellstorff

Significance of Habitat Modeling

• To find species, researchers have to look for ideal habitats.

• Modeling habitats through GIS allows for a better understanding of where and why species choose their habitats.

Study LocationTwo species of damselflies

Calopteryx aequabilis and Calopteryx maculata were observed and recorded along a 1 KM stretch of the Taunton River, West Bridgewater Massachusetts.

They are found along the banks, in varying levels of solar radiation.

Breeding Damselflies

• Damselflies found along the river are assumed to be of sexual maturity and breeding.

• Damselflies spend their initial time after emergence foraging in light gaps, to gain suitable energy reserves.

Affects of Light Intensity on Damselflies

• Light intensity can increase metabolic rates, and decrease energy reserves.

• Damselflies defend territory by entering battles of energy reserves.– Fly around tight against each other.

• Those with higher reserves can defend territories longer.

Early June End of July

Changes In Vegetation

Research Questions

• Where do breeding Damselflies of the order Calopteryx inhabit along the Taunton River?

• Where do C. maculata inhabit opposed to C. aequabilis.

• Where do female C. aequabilis inhabit?• Where can female C. aequabilis be found

perched along the Taunton River?

Male C. maculataEbony Jewelwing

Female C. aequabilisRiver Jewelwing

Male C. aequabilisRiver Jewelwing

Female C. maculataEbony Jewelwing

Collection of Field Data.

• Data was collected from June 2, 2008 to July 21, 2008 during 20 field sessions.

• 434 Calopteryx Damselflies were recorded.

• C. aequabilis had peak activity on June 11.

• C. maculata had peak activity on July 20.

Collection of Field Data

Input Data into Excel Sheets

Convert to DBF_IV File

From DBF_IV to GPS points on

ArcMap

Using DEM: Calculate Slope

and Solar Radiation

Intersect Binary Layers with

Buffered Taunton River

Statistical Analyses to Determine

Habitat Criteria

Reclass Solar Radiation and Slope (Binary)

Identify Damselflies with Binary Taunton

River.

Weight Attributes

Collection of Field Data

•Observation Time•Species•Sex•Light Intensity•GPS coordinates•Behavior (Flying, Perched, Fighting, Copulation, Ovipositing) •Bank Side

Behaviors

Significant Datat-Test: Two-Sample Assuming Equal Variances

  Variable 1 Variable 2

Mean911.941634

2 434.9151515

Variance56567.5239

2 140612.9928Observations 257 165

Pooled Variance89385.2784

2Hypothesized Mean Difference 0df 420

t Stat15.9941733

9

P(T<=t) one-tail1.30919E-

45

t Critical one-tail1.64848971

4

P(T<=t) two-tail2.61839E-

45

t Critical two-tail1.96562820

7  

Aeq VS. Mac Light Intesity

t-Test: Two-Sample Assuming Equal Variances

  Variable 1 Variable 2

Mean 0.219115872 0.679948848

Variance 0.185262101 1.001853354

Observations 257 165

Pooled Variance 0.504121543Hypothesized Mean Difference 0

df 420

t Stat -6.506212286

P(T<=t) one-tail 1.10E-10

t Critical one-tail 1.648489714

P(T<=t) two-tail 2.1968E-10

t Critical two-tail 1.965628207  

Aeq Vs. Mac Slope

• GPS coordinates of damselflies were overlaid onto images of the Taunton River.

• Using a digital elevation model (DEM) slope and solar radiation of each damselfly was calculated.

Geographic Information Systems (GIS)

Creating the Models• Solar radiation and

slope data were reclassified into binary categories. – Values that coincided

with majority of field points were coded as a 1 , all other values were coded 0.

• Binary Code was intersected with a 15 M buffered Taunton River.

Creating the Models

• Attributes were separately weighted for each model.– Some attributes were more

important in predicting species, sex, or behavior.

Example: Predictive Model for All Damselflies of Both Species[Slope] *.24 + [June 11 Solar Radiation] *.24 + [July 20 Solar Radiation]*.26 + [Entire Summer Solar Radiation]*.26

Predictive Model For C. aequabilis & C. maculata

C. maculata Predictive Model

C. aequabilis Predictive Model

Female Calopteryx aequabilis Predictive Model

Perched Female C. aequabilis Predictive Model

Conclusions

• Validating the model– Check the accuracy, by going out to high and low

probability areas.– June-July 2009

• Potential improvements the model– Add attributes (Vegetation, Water Flow)– Data collection from more sites along the Taunton

River

Future Applications

• Locating new populations• Identifying areas for conservation• Observing endangered species of damselflies

and their habitat needs– Model their habitat criteria, to find new

populations.

Acknowledgements

• I would like to thank Bridgewater State College for the ATP Summer Grant.

• My mentor Dr. Darcy Boellstorff for her guidance throughout the project.

• MassGIS for the use of data layers in the project.