Friday, August 02, 2019

2019 Island Fox Status Update

In 2018 most island fox populations were stable, but not without risk factors. 



As expected, high temperatures and below average rainfall in 2018 contributed to lower pup numbers and reduced adult survivorship across all islands. As first documented on Catalina Island, island fox reproduction is linked to annual rainfall. Fortunately, normal rainfall levels in 2019 should benefit all island fox populations.

In 2019 Channel Island foxes face four major threats:
  • climate change: increasing regional temperatures and decreasing annual rainfall, which reduce food resources, increase wildfire threat, and promote parasite numbers
  • biosecurity: the introduction of non-native plants, animals, and diseases
  • parasites: rising tick numbers and tick-borne diseases; increased intestinal parasites on some islands
  • reduction of management funding
The following update is drawn from FIF notes taken at the 2019 Island Fox Conservation Working Group meeting. Population numbers reported here are the official estimates from each island manager, as calculated from the fall 2018 count and reported May 21, 2019. Download the detailed 2019 Island Fox Status Update


Greatest Concern 
San Miguel Island foxes robustly recovered from 15 individuals in 2000 to over 500 by 2010 (lime-green line on graph below). As a smaller island, it will always have a smaller fox population. In 2015, however, following several years of drought, the population began declining. As of fall 2018, the population has dropped to an estimated 171 individuals (a decline of over 70%). This decline may involve several interconnected threats: climate change, biosecurity and parasites. Details regarding San Miguel will be posted in coming days.



Improved
San Nicolas Island foxes declined by 59% to 260 individuals during consecutive years of drought from 2012–2015
(pink line on graph above). The US Navy initiated native plant restoration projects in conjunction with Channel Islands Restoration. As these plants, like prickly pear cactus, mature they are providing food and habitat for island foxes and prey species. The fox population has increased to a more stable number–estimated 400 individuals. 



Stable
Santa Rosa Island foxes may have reached capacity for the island (pink line on "larger islands" graph above). Native vegetation is recovering and increasing resource options for foxes during periods of drought. No island foxes have been lost to golden eagles on this island or San Miguel since 2010. Parasites, including tick-borne disease, are a growing concern on Santa Rosa. FIF has refurbished 7 radio collars, and funded dietary research and health testing measures in 2019.


Santa Cruz Island foxes have reached capacity for their habitat. As a result the population decreased naturally during 2018 (green line on "larger islands" graph above). Parasites, especially tick-borne Lyme disease, are an increasing concern. Because the Cruz population has been stable since 2014, there is pressure to reduce funds for monitoring. This poses a potential threat because this population receives elevated contact from the outside world via island visitors. FIF has refurbished 20 radio collars for monitoring in 2019.


Santa Catalina Island foxes have also reached capacity for their habitat. In reaction to decreased rainfall, this population also declined naturally in 2018
(red line on "larger islands" graph above). Parasites, especially tick-borne Lyme disease, and biosecurity are an increasing concern for this population. Lyme disease and canine herpes virus were both introduced via human visitors and their pets. Monitoring of disease exposure is vital to this populations continued health. FIF has funded 5 new radio collars and health testing measures in 2019.

San Clemente Island foxes live on the most southern Channel Island
(blue line on "smaller islands" graph above). In 2018, they were the first population to see deaths directly attributed to high temperatures. Reduced rainfall stressed the population and eight individual island foxes are known to have perished in the heatwave between June and July of 2018. Climate change is impacting this island fox most directly. 

Download the detailed 2019 Island Fox Status Update

Friday, July 26, 2019

Fox Foto Friday - What's That Island Fox Wearing

Yes, it is a new radio-tracking collar! 


Through your generous donations, FIF was able to fund 5 new radio-tracking collars for island foxes on Catalina Island. 

Catalina Island fox receives vaccination during health check
These new collars will be placed on island foxes during this summer/fall annual counting and health checks.

Are you keeping count? We are:
Our goal is to fund 8 more $220 refurbished collars for Santa Rosa/ San Miguel in 2019. 

With your help we can meet this important need.  
Please donate today

Friday, July 19, 2019

Bald Eagles Thriving and Maintaining Island Balance for Island Foxes

Across the Channel Islands, 2019 has been the best year for bald eagle reproduction since recovery efforts began 35 years ago. This spring 24 bald eagle chicks successfully fledged from nests. (That means they survived to fly.)

According to a press release from Channel Islands National Park: "This year there were 19 breeding bald eagle pairs on the Channel Islands producing 24 chicks, including 10 on Santa Cruz Island, 9 on Santa Catalina Island, two each on Anacapa and San Clemente Islands, and one on Santa Rosa Island."


Orange wing-tags mark Catalina-hatched bald eagles
Bald eagles are a vital part of the Channel Island ecosystem. As fishing eagles, they prey primarily on fish and other birds, as well as consuming carrion. Bald eagles do not typically eat mammal prey and therefore are not usually a threat to island foxes.

On occasion island foxes climb up into bald eagle nests. For the most part the foxes act as a clean-up crew picking up tidbits of food left behind by eagle chicks. Eaglets are typically either protected by a parent when very young or too large for island foxes to prey upon.

blue wing-tags mark no. island eagles
Bald eagles therefore help transfer vital nutrients from the marine environment up onto the island. They help provide marine resources to island foxes, deer mice, and the island ecosystem. Nitrogen and calcium from fish are dropped on the land or eaten and deposited via scat. Marine resources can then help to fertilize island plants.  


Island foxes and bald eagles lived in balance on the Channel Islands for thousands of years. The oldest bald eagle fossils found in Southern California are 35,000 yrs old and from the La Brea Tar Pits. Bald eagles declined between 1945 and 1960 because of the insecticide DDT which had been introduced by people into the surrounding marine environment. DDT and bald eagle.



Bald eagles historically kept golden eagles from colonizing the Channel Islands and, in doing so, protected the island fox. Though they are both called "eagles," bald eagles (Haliaeetus leucocephalus) and golden eagles (Aquila chrysaetos) are not closely related. They come from two distinct evolutionary branches of predatory birds that separated and became competitors more than 12 million years ago. (By comparison, humans and chimpanzees diverged from a common ancestor just 7 million years ago.)

Golden eagles are mammal predators; they specialize in hunting small mammals about the size of a football (rabbits, ground squirrels, deer fawns, marmot, etc.) . Golden eagles hunt island foxes. They also eat carrion. Because both species will eat something that is already dead, they are known to take food from each other. There have been accounts of a bald eagle taking a dead island fox body from a golden eagle.


These two large birds have evolved to specialize in different food, but they compete for territory and nesting sites. Around the world fishing eagles and mammal-eating eagles are in competition with each other. You might think of them like dogs and cats–they share an ancestor, both are predators, but they have different specializations. They put up with each other at times, they will steal food from each, and in a confined space, like the islands, they just don't get along.

Though both bald and golden eagles are similar in size, resident bald eagles on the islands are frequently in mated pairs. Golden eagles encountering the islands are typically migrating individuals. This two-on-one situation gives bald eagles the upper hand.

When the Channel Islands' bald eagle population is thriving, there is no room for golden eagles and the habitat is safer for island foxes. Check out live bald eagle nest cams on the islands: http://www.iws.org/livecams.html

Friday, July 12, 2019

Foxes on Santa Cruz Island are Wearing FIF Collars


This island fox was captured and counted this week on Santa Cruz Island. 

She received a health check and her radio-tracking collar was replaced with a newly refurbished collar. Her old collar will come off and be eligible for refurbishing. 



Earlier this year, 20 radio collars from Santa Cruz Island were sent in for refurbishing and funded by FIF.

In just a few minutes this little fox was released back into the wild. Her refurbished radio collar has a battery that will last 2-3 years.


Her microchip enables biologists to identify her as a specific individual. If she is caught again this summer, the microchip reader will quickly identify her so that she can be released immediately without being handled.

Your donation of $220 would recycle her used radio collar to be placed on another island fox.

Saturday, July 06, 2019

Research Grant Deadline - July 12, 2019


The more we know about island foxes, the better we can play a positive role in their continued survival.

Friends of the Island Fox is accepting proposals for research projects that improve our scientific understanding of island foxes. Grant funding up to $5,000 is available.

The deadline for this year's applications is July 12, 2019.



Friends of the Island Fox Funded Research


Other Researchers:

We hope you are noticing that island fox research is filled with innovative women.


For other research regarding island foxes: 

Wednesday, July 03, 2019

Fox Foto Friday - Radio Collars Going On Island Foxes

photo courtesy of M. Navarro, CINP
Island foxes on Santa Cruz Island are receiving health checks and being fitted with newly refurbished radio tracking collars RIGHT NOW!

You refurbished these radio collars and today they are going on island foxes.

Tuesday, June 25, 2019

More Radio Collars for Island Foxes !


This island fox is smiling because it is wearing a newly refurbished radio collar. More about M152

Two things happened this week:
  • 7 newly refurbished radio collars arrived at Channel Islands National Park to be deployed on San Miguel and Santa Rosa Island foxes
  • FIF funded our 27th radio collar this year!

Twenty refurbished radio collars went to Santa Cruz Island in May to be fitted on island foxes this summer. 

You helped fund these radio collars to monitor island fox health and welfare

But we aren't done yet. 

Health checks and annual counting are starting across the islands. This is when old damaged radio collars are removed and replaced with new or refurbished radio collars. 

 


FIF is hoping to fund:

  • 5 more $350 new collar
  • 13 more $220 refurbished collars 

We know we can do this with YOUR HELP!


The time to radio collar island foxes is right NOW! 
Please DONATE TODAY 

Monday, June 10, 2019

FIF Funds Important Health Investigations for Island Foxes

Why are these biologists smiling? Because you are helping island foxes.

Mike Watling (FIF) presents funds to Lara Brenner (CIC) and Laura Shaskey (CINP)

At the annual meeting of the Island Fox Conservation Working Group, Mike Watling, a member of the Friends of the Island Fox Advisory Committee, presented FIF donations to support important investigations into the health of island foxes.

$3,000 to the Fox Program at Catalina Island Conservancy
tick attached to fox lower eyelid
This funding will test a second year of tick samples to determine the threat to island foxes from Lyme disease introduced to several islands in 2018. More on tick-borne disease testing. 

It also represents support from a Fresno Chaffee Zoo Wildlife Conservation grant that will analyze blood samples from island foxes on Catalina for signs of introduced disease. Once again a stow-away raccoon was recently stopped before hopping from a private boat to Catalina Island. Introduction of new diseases via pets and transported wildlife continue to be a problem for all islands, but especially Catalina. In 2018, blood samples revealed for the first time that a small number of Catalina Island foxes were exposed to a form of canine herpes virus. This important testing also detected exposure to a common dog illness, Coronavirus. 30% of the tested island foxes had been exposed to Coronavirus. Fortunately, no island foxes are known to have died from this disease.


$2,000 to the Fox Program at Channel Islands National Park
Intestinal parasites are causing early deaths among island foxes on San Miguel Island. This funding is part of a multi-pronged investigation to understand why and how new parasites are plaguing foxes on this island and why well-known parasites are causing greater impacts on San Miguel Island foxes. (see other ways FIF is helping this investigation)  

When you donate to FIF 
your donations go right to work helping island foxes.
  


Friday, May 24, 2019

You Can Help Island Foxes with Radio Collars


These island fox radio collars have gone to the shop to be refurbished. They have been chewed on, rubbed on rocks, and used as teething bars by island fox pups. But, with your help these collars can be repaired and used to help island foxes, again.

Radio-tracking collars protect whole islands of island foxes.

Radio-tracking collars can also be used for specific situations:

Which foxes wear radio-tracking collars?
 
Soon the radio collars above will be renewed and ready for the field. Before they can start making a difference, Friends of the Island Fox needs to pay for them. 

Refurbishing these 20 radio collars costs over $4,000

Your donation can help put these radio collars back on a wild island fox. 

Please DONATE TODAY 
to help monitor island foxes all year long.

Friday, May 10, 2019

This Island Fox Pup Needs You!

Across the Channel Islands, winter rains have renewed the native island plants and increased food resources for island foxes. 

2019 should be a good year for island fox pups!


Most island foxes are born in April. For the first several months of their lives, they depend on their mother for milk. Both parents will then bring food to the youngsters back at the den. Pups, generally, emerge in June and over the summer their parents teach them how to hunt and find native fruit. Healthy island fox parents have a head start in raising healthy pups.

You can help keep island foxes healthy and safe. 

This year the need for radio-tracking collars is greater than ever.

On each island 50–60 island foxes wear radio-tracking collars. Each year 30% to 50% of the collars need to be replaced or refurbished.

 

In 2019, Friends of the Island Fox is trying to fund:
island fox is vaccinated during health check
These radio collars will be assigned to island foxes this summer and fall during annual counting and health checks. A radio-tracking collar monitors an island fox's movements and signals to biologists when an island fox has died. Radio-tracking collars provide the first alert that disease, parasites, or unexpected predators have killed an island fox.

The sooner biologists can respond to a new threat, the more island foxes can be protected.

Friends of the Island Fox is also helping to fund important investigations into new health threats facing island foxes:
photo courtesy of Inge Rose
Foxes need your help with science-based solutions.
  • $25 tests a tick sample for 5 diseases
  • $50 checks two blood samples
  • $100 analyzes diet from 10 whisker samples
  • $220 refurbishes a used radio collar
  • $350 funds a new radio collar
Island foxes need all of us to help assure the pups of 2019 grow up in a healthy island fox community.

Please DONATE today