Conservation Science Webinar Series

Conservation Science

The National Conservation Training Center's Conservation Science Webinar Series attempts to cut through the spin and rhetoric by providing the science behind conservation issues in the news.

This product is for educational purposes only. The opinions, ideas or data presented in this webinar series do not represent FWS policy or constitute endorsement by FWS. Some of the materials and images may be protected by copyright or may have been licenses to us by a third party and are restricted in their use.  Mention of any product names, companies, Web links, textbooks, or other references does not imply Federal endorsement.


Date: December 9th, 2014
Time: 2:00-3:00PM ET

Introduced Parasitic Nest Fly reduces Survival of Darwin's Finches: Is there a Solution?

Captioning: Captioning Services will be available for this webinar.
Archive: If you are unable to attend this webinar, it will be recorded and posted on the Conservation Science Webinar Series Archive approximately 1-2 weeks after the presentation.
Presenter: Dr. Sarah Knutie, University of South Florida.
Description: finche heads Introduced parasites are a threat to biodiversity when naïve hosts lack
effective defenses against such parasites. Several parasites have recently colonized the Galápagos Islands, threatening native bird populations. For example, the introduced parasitic nest fly Philornis downsi (Diptera: Muscidae) has been implicated in the decline of endangered species of Darwin’s finches, such as the mangrove finch (Camarhynchus heliobates). First, I will present data on the effect of P. downsi on Darwin’s finch nestling survival; nests directly fumigated with a mild insecticide (1% permethrin solution) had fewer parasites and fledged more offspring than nests treated with water. I will then show that Darwin’s finches can be encouraged to “self-fumigate” nests with cotton fibers that have been treated with a 1% permethrin solution. Nests with treated cotton had significantly fewer P. downsi than control nests, and nests containing at least one gram of treated cotton were virtually parasite-free. The results from this study demonstrate that self-fumigation can be used to mitigate the effect of nest flies on Darwin’s finches and potentially in other systems.


Registration iconRegister for the webinar.



Marilyn Williams, Training Technician, Conservation Science and Policy Branch, National Conservation Training Center at 304-876-7940; e-mail


Matthew Patterson, Course Leader, Conservation Science and Policy Branch, National Conservation Training Center at 304-876-7473; e-mail