Showing posts with label Dr. Alexandra DeCandia. Show all posts
Showing posts with label Dr. Alexandra DeCandia. Show all posts

Friday, May 10, 2024

Date With A Fox - Island Fox Research with Juliann Schamel and Dr. Alexandria DeCandia

Friends of the Island Fox's Virtual Program on current island fox research.

"Date With A Fox"

with guests Juliann Schamel and Dr. Alexandra DeCandia

from Tuesday, April 30th

The April program highlighted current findings on island fox diet and microbiome. Microbiome investigations can help us understand how island foxes and island spotted skunks are using resources in the island ecosystem. Dietary investigations analyzing stable isotopes in whisker samples are revealing changes in island fox diet as their population size recovers and potential resource competition with island spotted skunks. 

Both research presenters are past recipients of Friends of the Island Fox Research Grants.

 



 

 

Dr. Alexandra DeCandia is an Assistant Teaching Professor in the Biology Dept. at Georgetown University and works with the Center for Conservation Genomics at the Smithsonian's National Zoo and Conservation Biology Institute. Her work has been published in Molecular Ecology and she is currently working on a joint project with Juliann Schamel supported by Friends of the Island Fox.

 

Juliann Schamel is a Biological Science Technician working with island foxes at Channel Islands National Park and a graduate student in ecology and conservation at the University of Aberdeen, Scotland. Her work has been published in PLOS ONE and she presented a poster on island fox and island spotted skunk dietary overlap at the California Island Symposium. 

Informed conservation decisions for island foxes and island spotted skunks depend on scientific knowledge.


Friends of the Island Fox is currently 

accepting applications for our 2024 FIF Research Grant.


Subscribe to the FIF bi-monthly e-newsletter for invitations to upcoming "Date with a Fox" presentations.

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

Tuesday, December 21, 2021

Island Fox Microbiome at the Smithsonian!

FIF's 2020 Research Grant recipient Dr. Alexandra DeCandia recently spoke about her work investigating the island fox microbiome

Watch the video of the program

Here's a behind the scenes look at her process extracting the DNA of different microbes from the island fox swab samples.

Dr. Allie reports: 

I inventoried over 800 swabs and over 300 blood samples collected from Channel Island foxes and island spotted skunks in 2020. I then extracted DNA and prepared samples for microbiome sequencing (a process called "library preparation"). The last step of the library preparation is cleaning the library–in essence, removing all of the DNA fragments that I don't want to ultimately sequence.


Although it may seem like a straightforward process, this took a bit of troubleshooting. After a few failed attempts, I worked with the lab manager at the Smithsonian National Zoo's Center for Conservation Genomics to learn how to run an "eGel". In this approach, you put your library in an agarose gel (which looks like a think rectangle of gelatin), run an electrical current through the gel to separate DNA fragments based on size...


(under UV light, the fragments look like glowing bands of the gel), and then pull out the band you want to sequence (in my case, fragments roughly 400 base pairs in length).


Then the DNA had to be treated to remove "gel particles and other potential contaminants."

Overall, this was a nerve-wracking process, but thankfully it worked!

Dr. Allie has submitted all seven sequencing libraries to the Princeton University Genomics Core Facility for sequencing. She reported on some preliminary findings during her "Date with a Fox" presentation. This is Fox Science at work! 

Your donations support this cutting-edge science that will provide important information regarding island fox health.  

Swab collection continues.

What is a microbiome? and Why is this important for island foxes?