Friday, March 15, 2024

FIF 2023 Research Grant to Investigate Individual Island Fox Impact


FIF awarded a second Research Grant in 2023 to Juliann Schamel, NPS biologist and graduate student in Ecology and Conservation at University of Aberdeen, Scotland...

Juliann Schamel in the field with island fox
 

and Dr. Alexandria DeCandia, biology professor at Georgetown University...

Dr. Alexandria DeCandia
 

for their project: From Microbes to Habitats: How Individual Fox Foraging Behavior Cascades Through an Ecosystem.

Schamel and De Candia are combining their respective work in stable isotope diet analysis and microbiome research to investigate the specific interconnections between 15 male island foxes and the island ecosystem. The team says, "Recent research has revealed that the island fox displays a high level of individual specialization, from their diet, to activity patterns, to the germination rate of scat-dispersed native seeds." This work builds on stable isotope diet analysis that Schamel presented at the Channel Island Symposium that demonstrated that diet specialization is occurring on Santa Rosa Island

GPS radio collar deployed on Santa Rosa Island

The 15 island foxes to be studied were part of a territory range investigation monitoring island fox movement with GPS radio collars by FIF 2021 Research Grant recipient Katie Elder. The final collection of data occurred in December 2023 when the island foxes were recaptured and their GPS collars removed.

Combining specific daily movement data (over the course of a year) with stable isotope diet data from individual whisker samples and microbiome swabs of gut microfloral offers a unique window into the lives of these individual island foxes. 

Microbiome sample swabs
 

It's easy to assume that island foxes, as a species, have a specifically defined relationship with plants and animals in the island ecosystem. However, Schamel's island fox dietary data has revealed a great deal of individualism in dietary choice, especially when resources are abundant. Some island foxes are eating beach foods, some are fruit specialists, others prey predominantly on deer mice.

Island fox whisker sample being collected
 

This investigation will try to reveal "a more holistic understanding of island foxes," DeCandia says. "[H]ost-associated microbes are critical to ... digestion and immunity,... By linking gut microbial communities with individual diet, movement, and activity patterns, we can begin to untangle the eco-evolutionary factors shaping these island hosts, their microbes, and the ecosystem in which they live."

Comparing microbiome of island fox and island spotted skunk, A. DeCandia
 

Friends of the Island Fox is proud to invest in this cutting-edge, multidisciplinary scientific investigation that brings together academic and governmental organizations and investigators. Whisker samples will be processed and analyzed by Julianne Schamel and Seth Newsome at the Center for Stable Isotopes at the University of New Mexico. DNA from microbiome swabs will be extracted by Alexandria DeCandia at the Center for Conservation Genomics at the Smithsonian's National Zoo and Conservation Biology Institute. Undergraduate researchers at Georgetown University, University of New Mexico, and California State University Channel Islands will actively participate in sample collection, laboratory preparation, data analysis and interpretation, and co-authorship of findings. 

Your donations help grow scientific knowledge and the next generation of scientists! 

Applications for FIF's 2024 Research Grant 

will be available March 22

Friday, March 08, 2024

Stable Isotopes Document Decade of Dietary Change in Island Foxes


Juliann Schamel has been researching island fox diet using stable isotopes in whisker samples since 2018. Friends of the Island Fox has supported the processing of whisker samples through several Research Grants. In November of 2023, Schamel presented the following poster of her latest work at the California Islands Symposium.

Using Stable Isotopes to Assess a Decade of Dietary Resource Use in Two Sympatric Island Endemics: The Island Fox and the Island Spotted Skunk (link to complete poster)

Island foxes and island spotted skunks live together on two islands, Santa Rosa and Santa Cruz. When island fox numbers crashed due to predation by golden eagles, island spotted skunk numbers appeared to increase dramatically. In 2011, on Santa Rosa Island, there were still fewer than 90 island foxes in the wild. During annual health checks, whisker samples were collected from both island foxes and island spotted skunks in a northern area of the island and stored for later analysis of what food resources each species was using.

In 2011, island spotted skunks out numbered island foxes in the wild. Stable isotope analysis shows that the skunks and foxes were using different resources. 

J. Schamel, 2023 poster
 

Carbon and nitrogen isotopes travel up the food chain leaving a specific isotope signature for plant and animal resources. Literally, you are what you eat and isotopes from a mammal's diet are laid down chronologically in hair or fur. A single island fox whisker can provide 5–6 months of weekly diet data. On the graph above, native terrestrial plant foods, like manzanita berries, are high in Carbon and low in Nitrogen. A deer mouse is the accumulation of its own, mostly plant diet; it has a mid-range Carbon and Nitrogen signature. In the graph above, the blue data points represent island fox diet and the orange data points represent island spotted skunk diet. 

In 2011, when island fox numbers in the wild were low, their diet tended to be higher on the food chain or trophic level: deer mice, birds and reptiles. The data suggested separate diet niches for island foxes and island spotted skunks. The skunks were eating primarily, lower level prey, like insects, and some plant foods.

J. Schamel, 2023 poster

In 2014, continuing drought influenced wildlife survival; island fox and island spotted skunks were nearly even in number on Santa Rosa Island. Island foxes expanded their diet, including marine resources, and island spotted skunks preyed more on deer mice and higher level prey. The two predators began competing for resources.

J. Schamel, 2023 poster

By 2018, the island fox population had recovered, but island spotted skunks appeared to decline in number. (Counting island spotted skunks) As island fox density increased across the island, they dramatically broadened their diet–from native fruit through a range of prey species. The spotted skunks maintained a more narrow diet, but they were now in constant competition with island foxes. What will this mean for the two species?

Schamel's work also revealed that individual island foxes are becoming specialized in their diet.

J. Schamel, 2023 poster
 

In the graphic above, each circle of data points represents an individual island fox and its diet. Some individuals appear to be specializing in fruit and insects, while others are eating predominately terrestrial prey. How is island fox diet continuing to change?

Save the date of April 30th at 6:30 pm PT 

Juliann Schamel will talk about her work on 

FIF's "Date with a Fox" webinar

sign-up for FIF's e-newsletter to receive an invitation

Measuring out a whisker sample

Whisker samples continue to be collected for both species. 

designed by island biologist, Stacy Baker

When you purchase an island spotted skunk pin

you send a sample of island spotted skunk whisker 

to the mass spectrometer to reveal stable isotopes.


Monday, February 26, 2024

You Did It! You Gave An Island Fox a Second Chance!

Thank you to our donors - near and far!

Over the past three days, you've responded with overwhelming support and raised the funds to pay for special orthopedic surgery needed for this young injured island fox. Her story

 
 
Thank you to:

  • FIF's long-time donors
  • Our Instagram followers
  • Our "X" followers especially our "Hijinkai" who love island foxes from afar in Japan

You all have helped to give this island fox a second chance on life.

Friday, February 23, 2024

Injured Island Fox Pup Gets Second Chance

 You can help this young island fox


Friends of the Island Fox is raising funds to pay for her orthopedic surgery

During the annual fall 2023 counting and island fox health checks on San Nicolas Island, biologists discovered this female pup with a recently injured right hind leg. The bones just above her foot, the metatarsal bones, had been fractured and the wound was open.

The injury was too severe for treatment on the remote Navy island. According to our friends with the U.S. Navy and the Santa Barbara Zoo: "The cause of the injury could not be determined but her chance for survival without intervention was minimal due [to] the risk of infection and septicemia posed by the open fracture. Releasing her without treatment with such an injury was determined to be both inhumane and life threatening."

island fox in the wild on Santa Cruz Island

Removing an island fox from the island where it lives is a big decision. Having evolved in isolation on their specific islands, once an island fox leaves an island it can not return. The biosecurity risk of introducing disease from the mainland to the wild population is too great.

The young fox was just old enough to be dispersing from her parents. With treatment and several months of observed convalescence, she had a good chance for full recovery. The cost of treatment, however, was being removed from the wild for the rest of her life.

 

The California Department of Fish and Wildlife (CDFW) gave special authorization to transport the state-protected species off of the island and off of the Navy's federal lands into state jurisdiction. She was flown off of San Nicolas Island and transferred to the Santa Barbara Zoo, which has "extensive experience in caring for orphaned and injured island foxes." A pair of brother San Clemente Island foxes who were abandoned by their parents during a drought year, currently live at the Santa Barbara Zoo. (Lewis and Clark)

In consultation with Dr. Steve Klause, a veterinary orthopedic surgeon, the Santa Barbara Zoo veterinary team initiated a conservative treatment plan. While the little fox responded well, the fracture did not initially heal as hoped. 


The Zoo team reached out to Friends of the Island Fox. The little female island fox needed special orthopedic surgical repair for internal fixation of the fracture. Could we help with some of the unexpected costs? 

FIF determined to raise the $1,900 needed.


On December 16, 2023, the little fox had her surgery and Dr. Julie Barnes Vice-President of Animal Care and Health tells us, she is doing well. The island fox still has several months of recuperation before she is fully healed. The Santa Barbara Zoo says "Once fully recovered, the fox will be transferred to a permanent home ... at an Association of Zoos and Aquariums (AZA) accredited facility where she will serve as an ambassador for the species - the first known San Nicolas Island fox to do so!"

Protecting island foxes is a community effort and saving this individual island fox is no different. People from the U.S. Navy, Santa Barbara Zoo, specialist veterinarians, and FIF are all investing in the future of this island fox.

You can HELP Too! 

Join our list of donors supporting this island fox

  • Recycling for Island Foxes and the Planet: $200
  • school children in Thousand Oaks, CA: $300+
  • FIF Instagram followers: $125
  • FIF "X" followers, including in Japan: $360
  • FIF returning donors: $1,190

Thursday, January 25, 2024

Unexpected Creatures During Island Fox Counting - Part 4

Welcome guest blogger Jessica Sanchez, wildlife veterinarian and FIF Board Member. She's explained how island foxes are captured annually in Part 1, shown how a fox's body condition is evaluated in Part 2, and demonstrated health procedures preformed on island foxes during an annual health check in Part 3. As she explains, she might be out capturing island foxes, but they aren't the only animals she encounters.

We also catch island spotted skunks, although this has become rarer in recent years.


You know you have caught a skunk even before you get to the trap because...

  1. of the smell
  2. they ball up all the grass and vegetation in the trap to make a cozy little nest for themselves

If you're lucky, they will still be asleep in this nest when you approach the trap the next morning. All of this gives you time to pause and carefully plan your approach to getting them out of the humane box trap. 

Skunks also get a microchip for identification and we take a tiny 2–3mm biopsy of the ear, with a special cartilage snip device, for genetic testing. Then they receive a thorough exam. (similar to island foxes) We try to handle the little skunks carefully so they don't spray us–this is for our benefit and theirs as it can take up to a couple of weeks for skunks to regenerate their spray and they need it to defend themselves. 

Currently, island spotted skunks are not vaccinated, though researchers are investigating options to potentially do so in the future.

Island spotted skunks aren't the only surprise that might be found in a box trap set out for island foxes. See what else Sanchez has found:

 
An island scrub-jay!


The final steps of a long day catching island foxes are to wash off any skunk spray and/or fleas, check yourself for ticks, enjoy a beautiful sunset, and get a good night's sleep before doing it again the next day! - Jessica Sanchez


Part 1 - capturing island foxes

Part 2 - Health Check: body condition

Part 3 - Health Check: veterinary procedures

 


Monday, January 22, 2024

Island Fox Gets a Health Check - Part 3

Welcome guest blogger Jessica Sanchez, wildlife veterinarian and FIF Board Member. She's explained how island foxes are captured annually in Part 1 and shown how a fox's body condition is evaluated in Part 2. But an island fox health check includes additional health measures.

We check the foxes for ectoparasites such as ticks, fleas, mites, and lice. We comb their fur to find fleas, and pay special attention to their ears, armpits, and belly area–where lice and ticks are often found. 

Ticks are collected so we can identify the species and test them for viruses or bacteria they might be carrying. Since ticks can feed on multiple hosts in their lifetime, testing the ticks tells us about what diseases the island spotted skunks, deermice, and other island species might be exposed to as well. 

 

 

We take a look in the fox's ears using an otoscope, just like the doctor uses to examine your ear canal. On Santa Catalina Island, where ear mites introduced by feral cats have been associated with ear tumors, foxes are treated with a topical medication to kill ear mites and reduce inflammation in the ear canal.

We collect blood from the jugular vein. This is used to test for exposure to disease, genetic analyses, and to look at other health parameters like liver and kidney function.

One of the most important steps is to administer vaccinations. A subset of the population is vaccinated every year for rabies and canine distemper virus. Neither disease is currently found on the Channel Islands, but we vaccinate as a preventative measure after the Santa Catalina Island foxes almost went extinct due to the introduction of canine distemper in 1999–2000. Vaccinations ensure that if there is ever an outbreak of either disease, at least the vaccinated foxes will survive to repopulate the island. (FIF's efforts to provide vaccine for island foxes in 2023)

A subset of foxes also gets radio collared. 

 

These collars are small, less than 5% of their body weight, and do not interfere with the foxes going about their daily life. Collars serve multiple purposes, allowing us to track the size and location of home ranges, monitor survival, and find dead animals quickly so their carcasses can be sent for necropsy ASAP to identify the cause of death. 

Most of the radio collared foxes are unvaccinated "sentinels," meaning if a disease outbreak occurs, they are not protected and may get sick, but their deaths will be detected via the change in their collar signal so we can recover the bodies for necropsy. Without collared animals, we would not know foxes were dying and would not be able to find the carcasses to get more information about the cause. Monitoring mortalities also gives us information on trends in other causes of death, such as internal parasites or being hit by cars, so we can address those threats as well.

Foxes are released after their workups and immediately run off! - Jessica Sanchez

 



In Part 4, Jessica details what happens when an island spotted skunk is unexpectedly caught during island fox health checks.



Friday, January 19, 2024

An Island Fox Gets a Health Check - Part 2

Welcome guest blogger Jessica Sanchez, wildlife veterinarian and FIF Board Member. In Part 1, she explained how island foxes are captured annually. Now, she'll take us through an island fox health check.

As biologists and veterinarians, we carefully remove the fox from the box trap, being sure not to get their tail caught in the door!

Island foxes are blindfolded to help keep them calm and reduce stress. Foxes do not have any natural predators on the Channel Islands so they are very brave, but they can still be stressed from handling by humans. Exams are quick and we do our best to be quiet and efficient. Island foxes are not sedated, so they can be released immediately and return to life as normal ASAP.

The health exam begins with an examination of teeth.

We open their mouths very gently so we can see the upper premolars. The wear on these teeth allows us to classify each animal into an "age class." Age classes range from 0 (pups born that year) to 4 (very old foxes with worn teeth). The pups also have serration on their incisors that have not yet worn smooth. Although age classes are not an exact age–and can vary by island, diet, and habitat (rougher food and sand wear teeth faster)–they give us a semi-standardized guide for assessing how old the population is overall. (more on using teeth to age island foxes)

We can also identify the pups of the year (less than a year old) by their appearance. They start out darkly colored and slowly transition to their adult gray/rufous/white. By the time we catch them during the summer/fall season, they look like mini-adults but with a rounder, fluffier shape.

Reproduction can be assessed in the females by examining their abdomens. A female who has not had pups that year will have white fur on her belly, with no mammary/nipple development (left, below). A female nursing pups will have the hair licked away from her nipples, the surrounding hair will be stained red from the saliva of the puppies, and her mammary tissue will be large and well developed from producing milk (right, below).

We do a thorough exam, assessing body condition and checking for any injuries. We check each foot to make sure they have no injuries to their claws, which are semi-retractable. Island foxes and grey foxes are unique among canids in that they can rotate their wrists, allowing them to grip and climb trees. (more on the island fox's ancestor, the grey fox)

Foxes often have grass awns or other debris stuck in their eyes, so we clean these out and remove any gunk that has accumulated. - Jessica Sanchez

In Health Check Part 3 - Jessica will detail the specific health measures taken for island foxes.

Part 4 - Other species encountered during health checks

Tuesday, January 16, 2024

How Do Biologists Capture Island Foxes?

Meet guest blogger, FIF Board Member, Jessica Sanchez. 

Sanchez is a wildlife veterinarian and epidemiologist who's been working with Channel Island foxes since 2006. She started her career managing the captive breeding and wild fox monitoring program on Santa Cruz Island. For her master's degree, she researched social interactions among island foxes, and modeled vaccination and monitoring methods to prevent and detect disease outbreaks. She is currently a consulting veterinarian for island foxes across the Channel Islands, providing medical care and advising on biosecurity and fox health research.

Every year, island managers and biologists conduct island-wide capture of wild island foxes to monitor the population size, reproduction, and health of individuals. This is done using the same locations every year, so direct comparisons can be made and trends identified. (counting island foxes)

The first step is finding a safe location to place a box trap–somewhere with flat ground, so it won't roll. It has to be out of the direct sun and wind, away from water with no risk of flooding, and where we can use vegetation to cover and disguise the capture device.

 


We capture foxes using wire, humane, live box traps; the very same ones used to capture feral cats. There is a "treadle plate" at the back that is attached to the door with a stiff wire. When the animal steps on the treadle, the door closes behind them.

We disguise the wire bottom by covering it lightly with grass or other vegetation. This also provides a comfortable bed for the fox to spend the night. We attract the fox with a small cup of fox-safe food at the very back, past the treadle. The fox must enter far enough to trigger the door and close it behind itself. An aromatic scent is also spread on a branch above the box trap–this scent travels longer distances than the smell of the food and attracts the fox to the area.

We cover the box trap with vegetation so the island fox is shaded and protected from any other animals that might come poking around. Then, we leave it overnight and return to check it first thing in the morning.

Sometimes, animals will try to get to the bait without going inside. This trap was disturbed by ravens! Ravens are extremely smart and will learn that the brightly colored "flagging" we put on trees to mark locations means there is an easy meal nearby.

If a fox is in the box trap, we first weigh both the trap and the fox. Once the fox is released, we subtract the weight of just the trap to calculate the fox's weight. An adult island fox will weigh between 1.5–3 kg, or 3–6 lbs, with foxes being slightly different sizes on different islands (largest on Santa Catalina, smallest on Santa Cruz).

We carefully remove the fox from the trap, being sure not to get their tail caught in the door!


The first thing we do once we have the fox in hand is scan it for a microchip tag, just like the ones used in dogs and cats. This tells us that the fox has been previously caught. The microchips are small implants, the size of a grain of rice, and are inserted under the skin near the shoulder blades using a needle.



The microchip provides lifelong identification of an individual so we can track its history–the locations it was captured, its age, any injuries, whether it had offspring, vaccines administered, any blood test results, and radio-collar frequencies.  - Jessica Sanchez

See F257's multi-year story.

The microchip can also alert the biologist that the captured fox has already had a health check that year. If so, it is immediately released.

 

If not, the island fox will receive a full health check. Follow as Jessica provides an island fox with a Health Check Part 2 - body condition. 

Health Check Part 3 - Preventative care 

Other species encountered during health checks

Saturday, December 16, 2023

Fox Foto Friday - Radio Collars on San Miguel Island Foxes

 Look who's getting radio tracking collars!

Island foxes born on San Miguel Island in April of 2023 are now adults and large enough to wear radio collars. Three were fitted with radio collars this week. The mask helps the island fox remain calm while the collar is being fitted.

Channel Island National Park biologists report this year's young adults are looking very healthy.

Watch them for yourself as they are released with their new radio collars.


 

Your donations to Friends of the Island Fox 

help to fund radio collars, vaccinations, and research 

into island fox health and behavior


Tuesday, November 28, 2023

Date With A Fox - Tim Coonan, Biologist

 Join Friends of the Island Fox for a Virtual Event !


"Date with a Fox" 

with guest Tim Coonan

Tuesday, December 5 

6:30 - 7:30 pm Pacific Time on Zoom

Tim Coonan is the retired Senior Biologist for Channel Islands National Park. He documented the mysterious decline of island foxes across the northern Channel Islands and uncovered that golden eagles had colonized the islands and were unexpectedly preying on island foxes. 


How were the decisions made to bring island foxes into captive breeding? What steps had to be taken to restore the ecosystem so that island foxes could return into the wild and recover their populations? Tim Coonan was there when only 15 individual island foxes remained on San Miguel Island and four populations were listed as Endangered Species. 

He released the last captive island foxes back into the wild and is the co-author of "Decline and Recovery of the Island Fox." 

Join FIF for an intimate conversation with Tim Coonan and a chance to ask your questions about island foxes.