Animal Behavior Study - Island Foxes (Urocyon littoralis)
Background
The Island Fox, a descendant of the mainland
gray fox, is native to six of the eight Channel
Islands. The foxes range in size from 10 to 12
inches in height and anywhere from 4 to 5
pounds in weight. Island foxes can be
identified by their distinct white and black
faces as well as their rust body coloring and
white underbodies. Each island population is
recognized as a separate subspecies and
therefore all vary slightly in genetic and
physical appearance. While island foxes can be found throughout the islands, they tend to prefer
shrubby wooded areas like the chaparral, coastal scrub, and oak woodlands. With no natural
predators the Island Fox is free to forage throughout the daylight hours. The foxes diet consists of
insects, deer mice, and plant items such as the fruit of the cactus, manzanita, and sea fig. The island
fox population experienced a sudden decrease in the 1990’s due to a multitude of ecological
factors. A decline in the Bald Eagle population caused by DDT contamination and non-native
ungulate populations allowed Golden Eagles to establish on the island. Increased predation of the
Island Foxes by the Golden Eagles caused the fox population to plummet so rapidly that the fox
became an endangered species. Captive breeding of the foxes and Golden Eagle removal allowed
the fox populations to reestablish. Today the fox has been moved off the IUCN endangered species
list to near threatened.
Technique Overview
While on Santa Cruz Island we will be observing and recording the foraging behaviors of the Island
Fox. Due to the uncertainty of finding a group of foxes, we will be focusing on the behavioral
technique known as focal-animal sampling in which we will observe and record the behavior of
one specific fox. Fox behavior will be recorded using a complete, or total frequency record where
all occurrences of the behavior of interest (foraging) will be recorded. Since foraging is generally
a non-social behavior, gathering relatively accurate data should be straightforward. Using the data
sheets and behavior codes provided we will observe a fox foraging for as long as we are able to do
so while we record all of the foxes associated behaviors. When gathering data we will take into
account the time the behavior initiated, the behavior itself (eating, digging, searching), the duration
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of the behavior, location at the time the behavior was exhibited, intraspecies interactions, and any
other relevant notes.
Benefits
❖ Total frequency records of individual animals provide insight into behavioral patterns
including: time of foraging, duration of foraging, habitat preference, dietary preference,
and intraspecies interaction patterns.
❖ Long term insight into any changes in the species preferences or food availability.
❖ Keeping records of food intake of the foxes can potentially show changes in other related
species
Limitations
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Inability to move close enough to the fox to discern the specific food item the fox is eating
Inability to locate any subjects to observe
Weather variability leading to undesirable foraging conditions for the foxes.
Limitations of the food diversity at a particular site may skew data
Considerations
❖ Time
➢ We will be observing the Island Fox in the late afternoon when we are most likely
to find them foraging. There is a possibility that we will not be able to locate an
individual to observe so, should we find one, it is vital that we be prepared and
ready to collect data to utilize all of our time.
❖ Equipment
➢ Binoculars
■ If we are not able to approach the fox, we may need binoculars to identify
what type of food the fox is eating
➢ Data sheets, clipboards, writing utensils
■ We may not have any flat surfaces to write on so clipboard may be helpful
➢ Behavior code guide
■ Gives shorthand codes for all aspects of the data collection to allow for
quick and concise data recording
Data Sheet
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❖ Behavior Code Guide
➢ The behavior code guide breaks down the behavior of interest into three categories, one of
them being the location at which the event occurred
➢ Each behavior or event and the location should be recorded on the data sheet using the
shorthand codes provided below
Category
Foraging
Behaviors
Behavior
Definition
Searching
Clearly looking for food but not actively trying to get
to a food item or eat a food item
FS
Digging
Digging through dirt or leaf litter in order to reach a
food item
FD
Climbing
Climbing up a tree in order to reach a food source
FC
Eating
The act of consuming the acquired food item
FE
Open Field
An open space in which the fox is not hidden by
any shrubbery
LO
Small shrubs, small trees, cacti
LC
Up in a Tree
Any tree that is clearly taller that the chaparral and
coastal shrubs
LT
Startled
Fox stops foraging and turns attention to a new
stimuli
ES
Leaving
Fox leaves visible range
EL
Intraspecies
Interaction Friendly
Any interaction between the fox and another animal
that does not result in a conflict/fox leaving the area
EF
Intraspecies
Interaction Aggressive
Any conflict that may arise between the fox and
another animal (hissing, fighting)
EA
Foraging/
Event Locations Chaparral
Behavior
Events
Code
❖ Data Sheet
➢ The data sheet provides a heading to record the name of the observer, location, date, start
time, end time, and weather.
➢ Below the header is the listing of all relative data points that need to be collected.
➢ For each instance of behavior the initial time of the behavior, the type of behavior, the
location of the behavior, the duration of the behavior, and any additional notes will be
recorded.
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Alternative Techniques
❖ Partial frequency sampling - takes record of only a one specific behavior and does not necessarily
represent all the behaviors displayed by a particular animal.
❖ One-zero sampling - takes record of whether a behavior did or did not ( one or zero) occur and not
the frequency at which the behavior occurred.
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