Morris Animal Foundation-funded researchers protect Ridgeway's hawks from botflies

October 30, 2018

Eggs hatching. Larvae burrowing under the skin and feeding on surrounding tissue. It's like a scene from a horror movie. Only this isn't a movie - it's happening in real life to an extremely endangered bird species, the Ridgway's hawk. The culprit is a botfly in the genus Philornis that is so aggressive it's eating hawk nestlings from the inside out.

Native to the Dominican Republic, around 300 Ridgway's hawks remain in the wild and researchers have been working diligently to save them. Botfly infestations are jeopardizing conservation efforts of not only Ridgway's hawks, but potentially other island raptors as well.

The story, though, is taking a turn for the better, thanks to Morris Animal Foundation-funded researchers at The Peregrine Fund. Dr. David Anderson and his team found a way to take on the Philornis botfly - and they're winning. The biologists are taking the fight to the botfly, scaling trees to reach Ridgway's hawk nests high in the canopy to apply an insecticide product. The findings and successes of their work recently were published in Animal Conservation.

"Peregrine Fund biologists found that botflies in the genus Philornis were practically wiping out all the hawk's nestlings," said Dr. David Anderson, Program Director at The Peregrine Fund. "We devised a solution - spraying nestlings with the chemical fipronil, the same chemical we use on our pets to get rid of fleas and ticks - and it seemed to work."

Initial results were promising but led to more questions. The team wanted to know exactly how much of an effect fipronil was having on the botflies, how many more birds survive if treated, and what impact their strategy would have on the hawk population overall.

"Fortunately, we found a great partner in Morris Animal Foundation, who saw the importance of this work," said Dr. Anderson. "After two years of study we can say that when we use the fipronil treatment on Ridgway's hawks, over 170 percent more nestlings survive than would without the treatment. That's huge. We have reversed the decline of a hawk that was nearing extinction."

As a bonus, this treatment could be used to help save other island birds in decline due to aggressive botfly infestations. There are endemic birds - that occur only in one place and nowhere else - living on islands in the Caribbean with declining populations and nobody knows why.

"One reason we are doing our research and sharing it, is to get other scientists asking if botflies might be affecting some declining species that they are studying," said Dr. Anderson. "If it is happening to Ridgway's hawks, maybe it is happening to other bird species, too."

"When we think about saving endangered species, many think of habitat conservation as the first line of defense," said Dr. Kelly Diehl, Interim Vice President of Scientific Programs at Morris Animal Foundation. "Another important piece of the puzzle is animal health, and we are proud to work with partners like The Peregrine Fund to put this puzzle piece in place and help save critically endangered species around the world, like the Ridgway's hawk."
About Morris Animal Foundation

Morris Animal Foundation's mission is to bridge science and resources to advance the health of animals. Founded by a veterinarian in 1948, we fund and conduct critical health studies for the benefit of all animals. Learn more at

Morris Animal Foundation

Related Bird Species Articles from Brightsurf:

Abundance of prey species is key to bird diversity in cities
A team of scientists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) and the Technische Universität Berlin (TUB) collaborated to analyse breeding bird data from the Senate of Berlin gathered by citizen scientists.

Shifts seen in breeding times and duration for 73 boreal bird species over 40 years
In a new study out this week, a team including forest ecologist Malcolm Itter at the University of Massachusetts Amherst reports finding ''clear evidence of a contraction of the breeding period'' among boreal birds in Finland over a 43-year span for which good quality data were available.

Two new species of parasite discovered in crabs -- discovery will help prevent infection of other marine species
Two new species of parasite, previously unknown to science, have been discovered in crabs in Swansea Bay, Wales, during a study on disease in the Celtic and Irish Seas.

Marine species are outpacing terrestrial species in the race against global warming
Global warming is causing species to search for more temperate environments in which to migrate to, but it is marine species -- according to the latest results of a Franco-American study mainly involving scientists from the CNRS, Ifremer, the Université Toulouse III-Paul Sabatier and the University of Picardy Jules Verne -- that are leading the way by moving up to six times faster towards the poles than their terrestrial congeners.

Analysis of bird species reveals how wings adapted to their environment and behavior
Bird wings adapted for long-distance flight are linked to their environment and behavior, according to new research on an extensive database of wing measurements, led by the University of Bristol.

Discovery of smallest known mesozoic dinosaur reveals new species in bird evolution
The discovery of a small, bird-like skull, described in an article in Nature, reveals a new species, Oculudentavis khaungraae, that could represent the smallest known Mesozoic dinosaur in the fossil record.

One species to four: New analysis documents new bird diversity in the Pacific
New findings from UMBC researchers and colleagues suggest several island bird populations in the Pacific that were previously designated as a single species actually comprise up to four distinct species.

APS tip sheet: Using bird song to determine bird size
An analysis of a bird species' unique rasps shows how sound fluctuations in birds' songs might reveal details about birds' body sizes.

Directed species loss from species-rich forests strongly decreases productivity
At high species richness, directed loss, but not random loss, of tree species strongly decreases forest productivity.

How bird flocks with multiple species behave like K-pop groups
Peer into a forest canopy, and you will likely spot multiple bird species flying and feeding together.

Read More: Bird Species News and Bird Species Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to