Tuesday, June 15, 2010

Team Working on Encephalitis Outbreak

It is with great pride that I bid farewell to Oscar, Alonso and Celestino this morning. They left with Jeremy Ledermann of the CDC and scientists from the Animal Health lab of the Agriculture Ministry (MIDA) to help collect samples in eastern Panama.

Here in Panama, the rumors have gotten ahead of the scientific facts, but I got the straight skinny from the Alex Martinez, my colleague and head of virology at the Gorgas. Basically, there appears to be an outbreak of either Venezuelan or Eastern Equine Encephalitis. One girl, nearly the same age as my daughter, has already died, and many horses have died.

The team is currently near Tortí and will move from there to the Metetí area. We'll be providing the Gorgas will all of the diagnostic samples. There are claims of dead birds in the area, but I should caution that there's lots of mis-information out there in a population that has been historically marginalized and is quite reasonably quite afraid.

STRI's role in this research is multi-faceted. Jose Loaiza will return from defending his PhD in medical entomology from McGill University and will identify the mosquitos collected. They will be then screened for virus, which we hope to sequence in order to tell us where the virus comes from. Blood serum samples from birds in the affected area will be screen for VEE and EEE antibodies. Together we will put this information together to try to understand the ecology of this outbreak. This is quite important because "migratory birds" were immediately blamed for the disease.

Typically, when an outbreak occurs, the conventional wisdom is that the virus was carried into the region somehow. Birds, especially migratory birds, are a convenient scapegoat. However, it may be that the virus has historically persisted as in a local reservoir. Hopefully with the combined study of the small rodent populations (sampling being done by MIDA) and the bird and mosquito populations (our group), we will be able to identify which animal species are part of the transmission cycle.

This is one of the strongest arguments for why we return to the same region year after year to collect specimens. Tissues from museum specimens provide a very useful source of information about the baseline conditions. Had we sampled previously in Metetí and Tortí, we would be able to evaluate changes in the serological condition of birds collected before the outbreak to those collected during and after the outbreak. Thanks to our CDC funded work in the Panama Canal watershed, we will have this baseline information for the center part of our country.

Thursday, January 14, 2010

Updates on the Escudo Hummingbird Question

The new year starts with an intern, Andrea Baquero, who hails from Colombia working in the lab with me. This week we began to collect nuclear DNA fragments from Amazilia hummingbirds (tzacatl on the mainland and Isla Colon) and handleyi (Isla Escudo) to get a more robust estimate of divergence time and gene flow between Escudo and the mainland. We haven't analyzed the preliminary data yet, but the few sequences that I've seen give me the general impression that gene flow was ceased between Escudo and the mainland for some time now.

I have to say that I'm pretty surprised at the level of DNA polymorphism in the Escudo population. Polymorphism is another word for genetic diversity, and as everyone remembers from high school biology, small inbred populations lose genetic diversity overtime due to genetic drift. However, we only have two small nuclear DNA fragments (as opposed to the mitochondrial DNA fragments I discussed earlier) and so this may be a consequence of chance. We will be collecting more data in the coming weeks, and I'll post an update.

I believe that this would make the Escudo Hummingbird, among all the world's hummingbirds, the species with the smallest range.

Saturday, October 3, 2009

New Website

I've got a website for my research up and running. It is a typical academic website, with links to research articles, contact info, etc. This blog will continue to highlight my work in progress, especially as it relates to Panama's birds. That website is: www.mj-miller.net

Tuesday, September 29, 2009

Delays in Posting

Too much time has passed since posting. We had a relaxing trip to the states earlier this month. The highlight was seeing U2 in concert in Boston! Frustratingly, upon our return to Panama, some one decided to break into our house and steal both laptops. It's taking me a while to get back to speed.

Nonetheless, our work with avian disease is growing rapidly, and I'm trying to juggle that with the on-going work in the diversification and speciation in Panamanian lowland birds. It should be a fun year ahead.

Tuesday, August 18, 2009

Just Back from the 127th Annual Meeting of the AOU

I just returned from Philadelphia, where U Penn was hosting the 127th edition of the annual meeting of the American Ornithologists' Union. The meeting was shorter by a day that typical meetings -- the economy even affects already frugal ornithologists. But we had a productive meeting. It was good to be a representative of STRI, Panama, and Neotropical birds at the conference. Lot's of folks are interested in what we've been uncovering about Panama's cryptic bird diversity, and there was a few really interesting talks that shook things up a bit. For example we learned that Green Violet-ears from Panama northward are only very distant relatives of conspecifics in the Andes.

Joel Cracraft reviewed recent geological literature which, along with trumpeters (Genus Psophia) suggests that western Amazonian forests are the most recent of the Amazonian biome. I'm sure the tropical tree ecologists at STRI would have something to say about that, since western Amazonia is the most species rich place in the world not just for birds, but also for trees, beetles, dragonflies, primates, etc. And we generally believe that older biomes have more species than younger ones. It's no understatement to say that I think that this was among the most controversial of talks at the meeting. (Top honors goes to an undergrad from Cornell who presented compelling evidence for a much better tree of the relationship among North American chickadees...the old tree didn't make sense, but that didn't stop it's authors from raising issue with the 22 year old who presented the new phylogenetic hypothesis.

Finally, a note about Panama's birds. George Angehr as
ked me to look at specimens of the Emerald Toucanet from throughout Panama. According t
o genetic data, the birds from Darien are sister to all the other birds from Central America, including
those that have throat colors other than blue. Genetic distances are large, and the authors of that study want to call each form a separate species. They didn't have material from the central part of Panama, but assumed it lumped in with the western Panama form (caeruleogularis) and not the eastern from (cognatus). But, George thinks that the birds from El Valle, Cerro Campana or elsewhere in central Panama may have Darien characteristics. Dear Birder, you can help out! Field notes of Emerald Toucanets are helpful. We're looking for presence of a red dot on the base of the mandible and some day-glo sky blue around the eye. In Philadelphia, I compared 100 year old specimens from Boquete and northern Colombia and found that both marks werk pretty consistent among individuals. Hat tip to Nick Sly for the figure. Nick is another recent undergrad from Cornell that I hope will be visiting us for a short-term research project in Panama soon.