Island Fox Behavior in 2017

courtesy of K. Schafer

In 2017, visitors to the Channel Islands have the opportunity to see something that was rare just a few years ago: wild island foxes interacting with each other.

When island foxes faced extinction in 2000, surviving individuals were brought into captive breeding facilities. From 2000-2006, seeing an island fox was a momentous occasion. Since 2008, all island foxes have been returned to the wild (with the exception of a few in mainland zoos). As the populations recovered across the islands, the opportunity to see island foxes hunting and interacting with each other has increased. (seeing island fox behavior on Santa Cruz Island 2015).

Witnessing interactive behavior between island foxes is a gift provided by the successful recovery of this once endangered species. Here are some of the behaviors we saw in late May:

Vocalization: Yes, island foxes vocalize. They bark, growl, and pups make soft whimpering and eecking sounds. 

• Barks are typically high pitched and evenly spaced. Barks may be repeated multiple times. In the distance, we heard an island fox bark eleven times in a row. This vocalization is used to warn an interloper that they have trespassed on an individual's territory. Island foxes may bark at each other or, occasionally, at humans. If an island fox barks at you, you are too close. Hear an island fox barking.
• The Growl of an island fox is low and soft. Typically this sound is used to warn off another island fox that has approached too close. We saw an island fox curled up sleeping by the side of a dry creek bed. A second island fox approached it, coming within five feet. The fox laying down, growled at the approacher. The second fox stopped, turned around, and went the other direction.
• Pup Sounds are typically only heard by parent foxes. The following pup vocalizations were recorded at the Santa Barbara Zoo from a pup that was abandoned by its parents. Hear island fox pup vocalization

Aggressive Territorial Behavior: Island foxes are very territorial. (Territory size) Living on an island with limited resources means quality territory is vital to survival. A pair of island foxes mates for life to protect their territory and the resources needed to feed themselves and their offspring. Challenges over territory can occasionally lead to aggressive behavior.

• Vocalizations (see above) are used to warn other foxes and avoid physical confrontation.
• Chasing can occur when an island fox intrudes into the territory of another island fox or pair. We saw one adult island fox chasing another adult island fox out of the campground area.
• Physical Altercations can occur between island foxes, especially over territory. Island foxes with floppy ears are typically older individuals who have had altercations with other island foxes. The cartilage of the external ear can be damaged by bites or twisting from other foxes. Over time, repeated damage leads to ears that flop down or may even be torn off. Bites to legs are also frequent injuries. Limping island foxes are often individuals that have been bested in a squabble.

island fox with damage to ear caused by another island fox

parent island fox with two pups

Affiliative Behavior: Island foxes are family oriented and pair bonded. They demonstrate caring and friendly behavior to family members. Female offspring remain in the same area as their parents and on occasion friendly behavior may occur between adult offspring and their parents or siblings.

• Care for Pups includes teaching pups to hunt and find food. It is not unusual during the summer to see an adult island fox leading a younger island fox around, showing them where to find specific food resources. Parents lick pups to groom them and also accept playful pounces from youngsters. Parents may discipline a misbehaving pup with a warning snarl, lifting the lips to show the teeth. The pup will show submission by lowering the head and body, flattening the ears, and licking the chin of the parent. Island Fox Pups
• Familial Recognition or recognizing family members is a behavior that is being seen more as fox families build generations. This May we saw a young adult island fox (1-2 years old) approach an elder island fox sleeping curled up along the dry creek bed. The younger fox came right up to the older fox and sniffed it. The older fox did not growl or demonstrate any aggressive behaviors and the younger fox did not try to chase the old fox or intimidate it in any way. This interaction was completely different from the aggressive behavior seen between two other adults on the same day (see The Growl above). Do island foxes continue to recognize family members throughout their life and maintain friendly behavior toward them? (See - Two adult island foxes meet) This is definitely an area that needs further research. 

island fox pup shows submissive behavior to parent

It is exciting that there are questions to be researched regarding island fox behavior. If we had lost the island foxes on Santa Cruz, Santa Rosa, San Miguel, and Santa Catalina Islands seventeen years ago, we would have also lost the opportunity to know this species better, to understand how it behaves, and how island isolation has changed its behavior from the mainland gray fox.

Island Foxes Take a Holiday

It's that time of year when island foxes take a holiday, a holiday from family life.

courtesy of National Park Service

Channel Island foxes typically form monogamous pairs. A male and a female with adjoining or overlapping territories, mate for life. Their committed relationship helps them to successfully defend territory with important food resources and enables them to successfully raise offspring.

Pups are born helpless and require dutiful parental care to survive. While the female may not allow the male into the den to see the pups for a period of time, the male plays an important role in supplying the female and the pups with food.

After the pups have been raised to an age where they can fend for themselves, 6-8 months, they set out to find their own territories. Female pups tend to establish territories close to their parents, while male pups disperse to the opposite side of the island. Male dispersal may be a natural selection adaptation to avoid breeding with close relatives.

When the pups head out, the parents tend to take a holiday from each other as well. From November to early January, island foxes live a more solitary life. Perhaps this separation enables island foxes to find adequate food during the late fall and early winter. Perhaps it creates a greater opportunity for those who have lost a mate, to find a new one. Or perhaps, after a spring and summer filled with parenting, island foxes just need a break and a little solitude.

When the male and female reunite in late December - early January, they will be ready to start a new family in the spring.

As well as monitoring for unexpected fatalities, radio tracking collars help biologists to understand island fox movement and territory size.