Great Horned Owl Diet

Geoffrey H. Palmer

Intro to Great Horned Owls

Intro to Great Horned Owls

• Classification

Intro to Great Horned Owls

• Classification• Distribution

Intro to Great Horned Owls

• Classification• Distribution• Morphology

Intro to Great Horned Owls

• Classification• Distribution• Morphology• Behavior & Diet

Does diet vary over time?

Why would diet vary over time?

Why would diet vary over time?

1. Prey availability & vulnerability

Why would diet vary over time?

1. Prey availability & vulnerability

2. Breeding season of owls

How can I measure diet variation?

How can I measure diet variation?

Field Site

Methods

19 Feb 2008 to 05 Apr 2008

Results

• 44 pellets

• 46 individuals

• 7 groups of small mammals

Dipodomys – Kangaroo rats

• 3 species

• 2 individuals

Reithrodontomys – Harvest mice

• 3 species

• 4 individuals

Sigmodon – Cotton rats

• 4 species

• 4 individuals

Neotoma - Woodrats

• 1 species

• 2 individuals

Peromyscus – Deer mice

• 4 species

• 15 individuals

Pocket Mice

• 5 species

• 17 individuals

Visits Totals

Dipidomys 1 1 0 0 0 2

Reithrodotomys 3 0 1 0 0 4

Sigmidon 2 1 0 1 0 4

Peromyscus 5 4 3 2 1 15

Pocket mice 8 3 6 0 0 17

Neotoma 1 0 0 1 0 2

Unknown 0 0 0 0 2 2

Pellets 19 10 8 5 2 44

Importance

1. Las Cienegas

Management Practices

Management Practices

Change in prey species:

1. Availability

2. Vulnerability

Importance

1. Las Cienegas

2. Range wide

Importance

1. Las Cienegas

2. Range wide

3. Other species

Importance

1. Las Cienegas

2. Range wide

3. Other species

Importance

1. Las Cienegas

2. Range wide

3. Other species

Importance

1. Las Cienegas

2. Range wide

3. Other species

Importance

1. Las Cienegas

2. Range wide

3. Other species

Importance

1. Las Cienegas

2. Range wide

3. Other species

Acknowledgements

Dr. JodyLee Duek

Jess Gwinn

Nate Gwinn

David Kahrs

Sonja Smith

?Questions?