Showing posts with label Katie Elder. Show all posts
Showing posts with label Katie Elder. Show all posts

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, November 19, 2021

FIF Research Grant to Investigate Island Fox Territory Size


Friends of the Island Fox is happy to announce Kathleen "Katie" Elder is the recipient of the FIF 2021 Island Fox Research Grant. 

island fox with GPS collar
In conjunction with the Biological Sciences Department of California Polytechnic University (CA Poly), San Luis Obispo, and Channel Islands National Park, Elder will be investigating territory size for individual male island foxes on Santa Rosa Island. This project will replicate and expand on a Santa Rosa study done in 2009–2010 using specially adapted GPS radio-tracking collars. Twelve years ago, Santa Rosa Island foxes were just starting to recover, with an estimated population size of 389 individuals. The GPS-collared male island foxes were calculated to have a territory size on Santa Rosa of 3.39 square kilometers (Drake et al. 2015).

Two island fox populations, which have not encountered recent population declines–San Nicolas and San Clemente Islands–have been found to have vastly different territorial sizes: 

  • San Nicolas Island (2005–2006) 1.81 square kilometers (Powers 2009)
  • San Clemente (2010–2011) .42 square kilometers (Sanchez 2012)

In the fall of 2020, Santa Rosa Island was home to an estimated 2,657 island foxes. As the population has recovered fully, have territory sizes decreased? 

island fox on Santa Rosa Island, courtesy Tim Bean

Elder will be investigating whether the density of the island fox population impacts territory size and/or the extent of fox territory overlap. She'll also be looking at whether habitat quality is a factor in territory size or territory use during different parts of the day. Are there some habitat areas, like beaches, that are included in the territory of multiple foxes? How do these territorial animals manage areas of overlap? Do they access overlapping areas at different times of the day? Are individuals with inland territories venturing to beaches occasionally? Beach areas provide supplemental food resources, but also may be primary zones for contact with introduced species and disease vectors.

Understanding territory size, overlap, and use, impacts island fox management. Territory-size data plays a role in the algorithms for calculating overall island population estimates. If the data on territory size is outdated, population estimates could be over- or understated. If specific habitats or areas are more important to island fox success, identifying those areas will help secure targeted protections. Identifying areas where island foxes are more likely to encounter threats, may also help us find ways to reduce those negative impacts.

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It's Science, For Fox Sake!

  

More about FIF funded Research 

References:

Drake, E.M., B.L. Cypher, K. Ralls, J. D. Perrine, R. White, and T. J. Coonan.  2015. The Southwestern Naturalist. 60:247-255

 Sanchez, J. N. 2012. Spatial ecology of disease spread in the island fox. M.S. thesis, Humboldt State University, Arcata, California.