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Friday, October 10, 2014

How Small Is An Island Fox?

Santa Cruz Island fox, courtesy of Anita Machlis
Frequently the size of an island fox is compared to a house cat. However, that can be a bit misleading. 

While house cats average from 8-10 pounds in weight, some breeds can easily weigh up to 18 pounds. Cats typically stand 8-10 inches at the shoulder.

Island foxes on the other hand are considerably smaller. While size varies between the islands and the subspecies, adults range from a weight of 2.35 to 6 pounds. Their fur may give the appearance of bulk, but most island foxes are quite slight in their physic. Finding enough food is always a challenge for these island dwellers. 

The length of the legs varies between islands, but the tallest of the island foxes only stand 8 inches at the shoulder. The Santa Cruz Island fox, the smallest, typically stands 6.5 - 7 inches at the shoulder. 

In actuality, island foxes actually weigh 40% less and are 22% shorter than the average house cat.

While felines are designed for leaping and vertical climbing, island foxes have somewhat weak legs. They can run and climb horizontally, but they are not leapers.

Can you guess what this is?


This is the view from inside a recycling trash can. Island foxes have narrow bodies. The largest males have heads that are only 2.5 inches wide. If an island fox can get its head into an opening, it can usually get the rest of its body through as well. Most island foxes can easily fit through the opening for a can or bottle. 

Human trash can be attractive to an animal that has a hard time finding enough food. Once an island fox gets into a recycle bin or a slightly open trash can, it has a very hard time getting out. 


 How do island foxes measure up to other small fox species?
  • kit fox (Vulpes macrotis), North America: 4 - 4.85 pounds; stand 12 inches to the shoulder
  • fennec fox (Vulpes zerda), Africa: 3 -3.5 pounds; stand 8 inches to the shoulder
fennec fox (Vulpes zerda), courtesy of Pat Meyer
The kit fox and the fennec fox are more closely related to each other than either is to the island fox. Because of the range in size among island fox subspecies, some island foxes are smaller than fennec foxes. Some weigh more than kit foxes, but all are shorter than kit foxes. 

Monday, September 22, 2014

Island Fox Presentations for Audubon Chapters

How can you learn more about the current status of the Channel Island fox?

Friends of the Island Fox educators will be giving presentations at three different Audubon chapter meetings in Southern California over the next few months.

We'll be talking about the how the island fox became endangered, the efforts to save them, as well as the different island fox populations and their current status–successes and challenges.  

Come out and join us at one of the following locations:

Thursday, Sept. 25, 2014 - 7:00 PM

The San Fernando Valley Audubon
Encino Community Center 
4935 Balboa Blvd., Encino, CA


island scrub-jay

Tuesday, Nov. 18, 2014 - 7:00 PM

Palos Verde / South Bay Audubon
Madrona Nature Center 
3201 Plaza del Amo, Torrance, CA


bald eagle
 

Thursday, March 18, 2015 - 7:30 PM

El Dorado Audubon
El Dorado Nature Center in Long Beach
7550 E Spring St, Long Beach, CA

Island foxes have a very interconnected relationship with the birds in their ecosystem.

Or for information about Island Fox Programs for your organization or club contact pat@islandfox.org  

Wednesday, September 10, 2014

Fresno Chaffee Zoo Selects FIF for Five Year Grant

Fresno Chaffee Zoo representatives visiting Santa Cruz Island
The Animal Care Staff from the Fresno Chaffee Zoo has long supported island fox conservation. They first raised funds for radio-tracking collars in 2006.

The Fresno Chaffee Zoo awards conservation grants to a variety of worldwide conservation efforts each year. Over the past eight years, Friends of the Island Fox has received support from the Fresno Chaffee Zoo to fund:
This summer, we received notification that a five-year grant has been awarded to Friends of the Island Fox for island fox conservation. Of 66 applications only 8 were extend 5-year support. Among the grant recipients, FIF is the only organization working with a North American species in the United States!

We are thrilled by the support from our friends at the Fresno Chaffee Zoo. While Fresno may be over the hills from the Pacific Ocean and the Channel Islands, FIF has participated in Fresno's Earth Day celebration and found their visitors very interested in the island fox and its survival.


The success of island fox conservation is based on local support and dedicated partnerships. The first year of the Fresno Chaffee Zoo grant supported important serology or blood testing looking for the presence of canine diseases among island foxes and the replacement of equipment important to annual counting and health checks.

Their second year of support will continue supporting fieldwork by replacing 43 of the field capture cages that safely enable island foxes to be captured for annual counting and health checks.

During the annual evaluation of the six populations, approximately 100 specially adapted capture cages are employed on each island. To ensure disease is not transferred between islands, each Channel Island has its own set of field equipment. With the financial support from our island fox friends at the Fresno Chaffee Zoo, Channel Island fox conservation enters its 17th year with much needed new equipment.

Tuesday, August 12, 2014

Bald Eagle Recovery Spreads Across Channel Islands

Channel Islands National Park reported in July that 60 bald eagles are currently living across California's Channel Islands. In spring 2014 there were sixteen known breeding pairs and fourteen chicks successfully fledged or flew from the nest.

As bald eagles reestablish their population, they help protect island foxes by reducing the probability that golden eagles will colonize the islands. Bald eagles primarily prey on fish and seabirds, while the golden eagles prey specifically on mammals. In the late 1990s, golden eagles nearly caused the extinction of the island fox on three islands: San Miguel, Santa Rosa and Santa Cruz.

Milestone bald eagle birth in 2013.

A landmark this year was the return of bald eagles to San Clemente Island. It is believed this is the first time bald eagles have attempted to nest on this southern island in approximately 50 years. The U.S. Navy manages San Clemente Island and they have been successful in protecting island foxes and other island endemic species. The bald eagles are evidence of recovering habitat on the windswept island. 

The newly established pair was unsuccessful in nesting in 2014, but hopes are high that the pair will find success in the future.

According to the National Park Service the pair of bald eagles combine the successes found on the other Channel Islands. The female was hatched near Juneau, Alaska, in 2004. She was relocated as a juvenile to Santa Cruz Island as part of the efforts to reestablish bald eagles on the National Park islands.

The male eagle is a young adult, hatched in 2007. He began life in an incubator on Santa Catalina Island and was placed in a bald eagle nest on the island, where he was raised by foster eagle parents. 

With a number of active bald eagle nests on Santa Cruz and Santa Catalina Islands, the young pair looked south for territory of their own. Biologists hope that eventually all of the Channel Islands will have resident bald eagles. The recovery of the bald eagle and the island fox is dramatically interconnected. Success for the bald eagles supports island fox recovery and stability.


See Current Island Fox Recovery, island by island.

Tuesday, July 29, 2014

Considering Epidemic Disease Threats to Island Foxes

courtesy of Paul Bronstein
What saved the Catalina Island fox from rapid extinction when canine distemper virus was introduced between 1998-1999? 

An isthmus and human action

Epidemic disease poses a major threat to naive island species like the Channel Island fox. When distemper was introduced via a raccoon transported unknowingly to the island, the disease spread rapidly throughout the island fox population. Nearly all of the 103 surviving Catalina Island foxes lived north of the isthmus, a narrow neck of land connecting the western and eastern parts of the island.


photo from NOAA of Santa Catalina Island
Fox traffic across this exposed area is minimal.

At the recent Island Fox Conservation Working Group Meeting, Brian Hudgens from the Institute for Wildlife Studies (IWS) reported on his findings “Mapping Epidemic Risk in Island Foxes.”

Working with Julie King from the Catalina Island Conservancy, they considered the map of Catalina Island and the areas where epidemic disease is most likely to be introduced via human visitors–the towns of Avalon and Two Harbors, beaches and harbors, and youth camps. They combined this with fox related factors:

  1. island fox population density on Catalina
  2. typical home range size of individual island foxes
  3. range overlap with neighboring island foxes
  4. number of interactions with neighboring foxes
It quickly became apparent that island fox density on Catalina Island is highest in the areas near human habitation; the areas which also pose the greatest risk for disease introduction.

Next, Hudgens created a computer model calculating how introduced canine distemper virus would travel across the island and through the island fox population. What they didn’t expect was that in most cases it didn’t matter where the disease was introduced, in 3 - 4 months an epidemic would cause 100% mortality island-wide. The only deviation was a reduction to 90-100% mortality, if the disease was introduced at the far western end of the island, with the isthmus to hinder the infection spread.


Adding vaccination into the modeling dramatically changed the modeling outcome and the most significant protection was provided by island-wide vaccination of individual island foxes. When a significant number of island foxes across the island were vaccinated in the model, animals that were not vaccinated had a four-times better chance of surviving as well.

Friends of the Island Fox funded 400 island fox distemper vaccinations in 2012.

Each vaccination for rabies or distemper costs $10.
 

Vaccination provides vital protection for these rare island foxes. Successful recovery can only be maintained through vigilant proactive protection.  

Tuesday, July 01, 2014

Channel Island Fox Status Update June 2014

photo courtesy of Dave Graber
photo courtesy of Kevin Schafer
The annual meeting of the Island Fox Conservation Working Group reported that the general status of the six subspecies of Channel Island foxes is GOOD.

All subspecies are maintaining stable populations of over 300 individuals. There are no known specific issues that put any of the Channel Island fox subspecies in eminent threat of extinction. Each island, however, faces its own concerns and challenges. 

  
Island Fox Update 2014 pdf, a specific island-by-island summary
  • San Miguel Island - 577 (low of 15 in the year 2000). Population recovered with over 500 individuals since 2010. Concern: New threat from parasites.
  • Santa Rosa Island - 894 (low of 15 in the year 2000). Population steadily increasing.
  • Santa Cruz Island - 1,085 (low of 62 in the year 2002). Population recovered and stable with over 1,000 individuals since 2009.
  • Santa Catalina Island - 1,852 (low of 103 in the year 2000). Population recovered and stable with over 1,000 individuals since 2010. Concern: Climate change impacts and high risk for introduced disease.
  • San Clemente Island - 1,002 (not Endangered). Population stable. Concern: New disease threat connected to mineral particulates in the air.
  • San Nicolas Island - 350 (not Endangered). Population high, but declining. Concern: Cause of decline currently unknown, see below.

Concerns:

As populations reach the carrying capacity on some islands, there are new challenges to island fox survival. Continued drought appears to be impacting prey and plant species on some islands, which in turn impacts the island fox. Not only are resources reduced, there may be new threats posed by parasites. (Spiny-headed worm on San Miguel Island).

raccoon stowaway on Catalina Express, Dec. 2013
photo courtesy of Ciara Virdan
Introduced disease remains a threat to all island foxes, especially on islands visited by people. Dogs, cats, and introduced species, like raccoons, are all avenues for disease to be transported to isolated and disease-naive island foxes.

 Canine distemper virus (CDV) caused the population collapse of island foxes on Santa Catalina in 1998-2000. Vaccination against CDV is part of protecting island foxes on all six islands. Island foxes, and many other wild species, are unable to withstand the standard CDV vaccine given to dogs and depend on a vaccine produced by Merial, the corporation that makes Frontline and other veterinary products. Unfortunately, there has been no production of the vaccine this year. If the vaccine is not available by fall counting and health checks, island foxes may go unprotected for the 2014-2015 year.


On San Nicholas Island where the fox population has been high and stable for years, annual monitoring has revealed a trend toward decline that is currently unexplained. A group of island foxes on San Nicolas Island will be radio collared in the fall during annual counting to help biologists determine the cause for the decline. (For more specifics see Island Fox Update 2014 pdf above)

Positive Notes:

While there are concerns regarding San Miguel and San Nicolas, island foxes are doing well. Working with U.C. Davis and veterinary pathologists, National Park biologists hope to determine the specific reasons behind the appearance of new parasites on San Miguel Island and the long-term threat they pose to the island fox population.

Monitoring with radio collars on San Nicolas Island will enable biologists to locate individual island foxes that die in a timely manner. Necropsies performed on these animals will help provide information regarding cause of death.

The most positive note of all is that the Island Fox Conservation Recovery Group continues to meet. Nothing is more important for the continued recovery of the island fox than bringing this group of people together who can share their expertise, their experience, and their creative solutions. Friends of the Island Fox thanks all of our donors who made this annual meeting possible!

Wednesday, June 18, 2014

Endangered Island Foxes Stabilizing But Need to Monitor Continues

courtesy of Kevin Schafer
The annual meeting of the Island Fox Conservation Working Group took place yesterday, hosted by Friends of the Island Fox

The good news is that the four endangered populations of island foxes on San Miguel, Santa Rosa, Santa Cruz, and Santa Catalina Islands continue to recover and stabilize. 

Island foxes on the two Navy islands, San Clemente and San Nicolas, are not considered endangered by the U.S. Fish & Wildlife Service (USFWS) and their populations remain stable and at high densities (number of individual animals per square kilometer).

The graph below shows population numbers for San Miguel Island through fall 2013. The population was initially estimated in 1994. Actual individuals were counted when island foxes were in captive breeding pens on the island. Through 2007, the island foxes on San Miguel were gradually returned to the wild. Wild population figures are estimated through an annual catching of individuals and computer extrapolation of that data. More on Counting Island Foxes.


The graph shows how San Miguel's population dropped dramatically due to golden eagle predation at the turn of the century. Fifteen surviving individuals became the founders of the current San Miguel Island fox subspecies; captive breeding by the National Park Service saved this subspecies from extinction.

The population has made an amazing and rapid recovery to a level greater than historically estimated before the crisis. Statistical analysis through fall 2013 calculated that for the fifth year in a row,  individual island foxes on San Miguel have a 90% chance of surviving through the next year and the potential for species extinction is very low.  

Currently the density of island foxes on San Miguel is very high, 10-20 individuals per kilometer in some habitat areas. National Park biologist Tim Coonan believes the data shows the San Miguel Island fox population has fully recovered and has reached the "carrying capacity" for this small island. This means the food and territory resources available on San Miguel can not support continued population increase. The minor population ups and downs since 2010 follow the pattern of a population responding to resource availability. 

Conservation efforts on behalf of the San Miguel Island fox have been very successful. Across Santa Rosa, Santa Cruz and Santa Catalina the stories of population recovery from the brink of extinction are all inspiring.


However, there is an additional cautionary chapter in the San Miguel story. As the island foxes in the National Park have recovered, funding has decreased for their management. The staff that works with the foxes on San Miguel and Santa Rosa has gone from six to three technicians. 

Since the end of 2013 thru May of 2014, seventeen radio-collared island foxes on San Miguel have died from peritonitis caused by a parasitic spiny-headed worm (the exact species is still being determined). This parasite has not been a problem on the Channel Islands before and typically does not cause mortality in canines. The spiny-headed worm is transmitted to the fox through another animal-species host that the fox has eaten.

Today as the biologists, veterinarians, land managers and government officials meet for a second day, they are sharing expertise and ideas about how to respond to this potential threat to the San Miguel Island fox. Over the next few months they will be looking for answers to new questions:
  • What prey species is carrying the parasite?
  • Have island foxes on San Miguel changed to a prey species that is a vector for this parasite?
  • Across San Miguel Island a higher number of island foxes are appearing underweight. Are these foxes infected with the parasite as well?
  • Is drought a factor in this problem?
  • Is high population density a factor?  
  • Why is the number of these parasites so high in individual foxes?
  • During the fall count, there appeared to be a very low number of pups on San Miguel. Is this a natural response to high population density and reduced resources? Is the parasite impacting female health and therefore reproduction?
  • Is the parasite a possible threat to other Channel Island fox subspecies?
Channel Island foxes are rare creatures. Prior to the near extinctions of 2000, little was known about this endemic California species. If there is one thing that has become obvious over the years, it is that change to the island habitat, either directly by people or indirectly through environmental toxins, climate change, or introduced invasive species, island fox survival requires vigilance. 

The continuity of public support and scientific experts engaged in island fox conservation is vital to maintaining this unique species into the future. Funding the Island Fox Conservation Working Group meeting is an important part of island fox conservation.

Stay tuned for more information from the Working Group meeting. 

Monday, June 09, 2014

Annual Meeting of Island Fox Conservation Working Group

photo courtesy of Channel Islands National Park
 Every year biologists, veterinarians, researchers, educators, private individuals, government officials and land managers involved with Channel Island foxes meet in June to share information. As the four endangered subspecies have approached population recovery, funding for this important annual meeting has weakened. 

This year the June 2014 meeting of 
the Island Fox Conservation Working Group 
is being hosted by Friends of the Island Fox!

Through the generous donations of private individuals and community organizations, FIF is making sure this important networking and sharing of scientific information continues. Thank you to all of our island fox supporters. You have made a huge difference for the continued success of endangered island fox recovery.

When the Working Group meets next week there will be specific updates on each island fox subspecies. (Six different subspecies). 

Representatives from Channel Islands National Park, the U.S. Fish & Wildlife Service (USFWS), Institute for Wildlife Studies, Catalina Island Conservancy, United States Navy, The Nature Conservancy, University of California at Davis School of Veterinary Medicine, Santa Barbara Zoo, Smithsonian Institute, Channel Islands Park Foundation and Friends of the Island Fox will present reports and discuss issues pertaining to island foxes.

Island fox having teeth checked during Health Check, NPS
Some of the Report Topics:

Proposed Issues for Discussion:

You can see the important items that will be addressed and information that will be shared. The greatest successes for endangered species come when people sit down together and share their expertise and ideas for solutions. 

Thank you again to all of our island fox friends that helped to continue this important meeting.

Tuesday, June 03, 2014

Let's Go FOXES!

The Fort Collins, Colorado, Foxes are celebrating endangered island foxes for the third year in a row. 

The Foxes are part of a summer Mountain Collegiate Baseball League and again this year they will help raise funds for island fox conservation at one of their home games. 

The Fort Collins Foxes meet the Winsor Beavers
on Sunday, June 8th in Fort Collins, CO

The team will raffle off a replica Major League jersey to raise funds to help support Channel Island foxes.


Fort Collins has a second connection to island foxes. Colorado State University at Fort Collins maintains physical scat and blood samples of island foxes from Santa Cruz Island. These specimens are important to biologists and researchers working on issues concerning island foxes.

If you can't attend Saturday's game you can still support foxes by wearing one of the many styles of Foxes' baseball caps. When you purchase a Foxes baseball cap on-line, the team will make a 15% donation to Friends of the Island Fox

GO Foxes!

Saturday, May 24, 2014

Students Helping Endangered Island Fox

Summer is a great time to visit the Channel Islands and the endangered island fox.

Island Fox Ambassadors from Carpinteria Family School
It is also a great time to contribute to island fox conservation. The students of Jan Silk's class at the Carpinteria Family School are Island Fox Ambassadors. Not only have they raised funds for island fox health checks, they participated in an additional service-learning project while visiting Santa Cruz Island in Channel Islands National Park.

During the years that Santa Cruz Island was a ranch, not only were large domestic livestock introduced to the island, so were invasive non-native plants. While the goats, pigs and sheep have been removed from Santa Cruz, the fennel and non-native grasses persist. Non-native plants typically do not provide food for wildlife and can push out the native plants. 

The students helped remove invasive fennel.


Trash left behind by visitors and campers can also be hazardous to native animals like the endangered island fox. The students gathered up any trash items they found and packed them off the island.

The students of Carpinteria Family School have shared their hearts with the endangered island fox and discovered not only California's Channel Islands but the role they can play as individuals and as a group in making a positive difference.

natural rocks on the beach on Santa Cruz Island

Friends of the Island Fox works with teachers, schools, youth groups and community organizations to build connections between people and the wildlife of the Channel Islands. 


For more on school programs and community presentations.

FIF school presentations are fully booked through June. We will begin scheduling for the next school year in Sept. To receive an e-mail regarding the schedule in 2014/15, e-mail islandfoxnews@gmail.com