1. Studying Squirrels

2. Gray and Fox Squirrels: Identification
Orange or rust backs and sides
Orange bellies
Black-fringed tail
Gray backs and sides
White or gray bellies
White-fringed tail
Has a black morph and albino form
Some variation in colors, can be fox squirrels with primarily white bellies and gray squirrels with hint of rust on backs and sides.

3. Some Other Differences
Gray squirrels prefer forest interior; fox squirrels like edges and sparse forest and even venture out in prairies and fields
Fox squirrels can be aggressive, often facing down predators
Gray squirrels are more cautious and will head for nearest tree instead of fighting
Except that gray squirrels will chase off fox squirrels
Fox squirrels will travel larger distances over land, even running from threat on land. Gray squirrels go immediately to nearest tree.

4. Some Similarities Like nuts in particular, but are opportunistic
Will cache nuts, especially in fall
Find nuts through sense of smell
Prefer to nest in tree cavities but will also make leaf nests
Have one brood in early spring and often a second midsummer
Can smell nuts up to 1 foot below snow
“Chases” in late winter include several males following a single female.
Interesting gray squirrel fact: overpopulation would trigger migrations. In early 19th century when east covered in dense hardwood forest, observers reported migrations through the trees – from tree to tree. A major migration of thousands of squirrels occurred in October 1968 in Tennessee, Georgia and North Carolina. Attributed to nut boom in 1967 followed by early frost and lack of nuts.

5. Animal Behavior
Ethology = the study of animal behavior and includes both what an animal does and why it does it.
Ethogram = a description, usually in the form of a list, of all of an animal’s normal behaviors.
Why study behavior:
What an animal does and how long it spends doing it
Indicate how an animal feels in its environment
Indicate learned versus innate behaviors
Allows for comparisons between different populations
Identification of area specific patterns
Does weather, season, etc influence behaviors?
Does the same species in different habitats behave in the same way?
Are there any learned behaviors?
Does the animal’s behavior change in the presence of humans?

6. Some Methods for Observing Behavior
Initially can be useful to create a list together, or provide students with a list of possible behaviors, with room to add more
Focal animal: choose a single animal and at set intervals record what it is doing
Group scans: at set intervals scan a group of individuals and record all of the behaviors observed
Need to also record date, time of day, weather conditions, and anything else that might impact the data.

7. Exploring Squirrel Behavior
Resting
Grooming
Eating or searching for food
Hiding or watching for danger

8. Travelling: ground, tree, etc.
Chasing
Begging
Caching
Travelling: ground, tree, etc.

9. Other Squirrel Investigations
One way to study squirrels and other animals is through FOOD!
Exploring the foraging behavior of animals can reveal a great deal about how they perceive their environment.
Can explore this by providing animals with artificial foraging trays.

10. Other Squirrel Investigations
Squirrel food preferences:
Different types of foods (e.g. sunflower seeds vs. hazelnuts vs. peanuts)
Shelled versus unshelled nuts (hazelnuts work great for this)
Seasonal differences in preferences
Presence of alternative food sources
Explore different substrates
Food colors
Temperature of the patch

11. Landscape of Fear Based on risk of predation
Some areas within a habitat are safer than others.
Squirrels prefer to spend their time near trees
Proximity to tree allows quick escape from predators
Shade of tree makes squirrel less visible

12. How to measure the landscape of fear?
Giving Up Density (GUD) is the amount of food left behind by a forager in a food patch
An indirect way to measure
Predation risk can then be measured by placing food patches in areas of varying risk.
If an animal feels safe, it will keep foraging until it depletes the food to the point it is no longer worthwhile to continue = less food left behind = lower GUD
If an animal does not feel safe, it will spend more time looking for predators than foraging, and is more likely to leave sooner = more food left behind = higher GUD

13. How to measure the landscape of fear?
Possible set-ups:
Near tree versus far
Near a road or path
Near a yard with a dog
Could also compare city squirrels to suburban squirrels to squirrels in more natural settings

14. The Landscape of Fear
By replicating the food patch setup in several locations throughout a habitat, we can actually map out the landscape of fear.

15. Experimental Data
In a given experiment, we can predict outcomes/formulate hypotheses.
Data can be analyzed by taking the average GUD of each patch type.

16. Experiment Write-Up
Can also discuss observations of things that may have affected the data, for example:
Weather conditions
Normal/abnormal activity in the area
Different characteristics of stations (near busy street, tucked away in the woods, etc.)

17. Project Squirrel Website: http://www.projectsquirrel.org/
Citizen scientist project through UIC and Chicago Academy of Science led by Dr. Joel Brown and several of his graduate students
Focused on gray and fox squirrels, specifically how the distribution and environments of these species differ
Some of the information they collect:
Kinds of trees in an observation site
Any dogs or cats around
In addition to being interesting animals to watch, squirrels can tell us a lot about our local environment and how it is changing. To gain this insight, we must gather data about as many individual squirrels in as many places as possible.
What to do:  Take a look around your home, office, school, or anywhere you are and, whether you see squirrels or not, click on the green button above to submit your observations.  We want to know where squirrels are as well as where they aren’t. How often:  You can submit as many observations from as many places as you like.  It’s most effective to submit at least one observation per site per season but the more observations the better. Who:  Anyone of any age can participate.  Make it an office game or a classroom project, compare notes with friends in other states, get your family involved—everyone can observe nature.