Tuesday, October 13, 2009
Although I don't have any exciting new field stories to recount, I haven't had to venture far from NESCent to have had a few close encounters with nature - including one that was much closer than expected. Pictured in the upper panel of the figure at right is a cool praying mantis that we found perched on the rear tire of my Aveo the other day. However, it was what happened to me this evening as I finished an easy run around dusk that really takes the cake. As I was running up the street towards my house in Old West Durham, I suddenly perceived the shadow of something flapping right above my head. Before I had time to react, I felt what later turned out to be talons and the weight of something quite large on my head! Of course, I did what almost any normal person would do (yell "Ahh, ahh!" and swat wildly). After hanging on to my scalp for a second, I felt it release, and then an enormous barred owl flew off my head and up to the telephone wires, where it hung out long enough for me to go back to my house and grab a camera to snap the (admittedly poor) photo in the lower panel at right. My neighbor reports that this is the 4th time he has heard of this owl attacking, and by interesting coincidence, several other owl attacks have recently been reported for North Carolina (here and here).
Sunday, October 4, 2009
Day 2 of talks in the 2009 Anolis Symposium hosted by the Museum of Comparative Zoology is drawing to a close this afternoon with some of the final scheduled talks of the meeting by Jonathan Losos, pictured right (upper panel); and by Dechronization blogger-in-chief Rich Glor (lower panel). This meeting has featured a large number of great talks, but I only have time & space to comment on a few here. In the morning session, we saw a whole series of presentations on invasive anoles (a "mini-symposium," to steal Jason Kolbe's words), including a great talk by Todd Campbell on the natural history and ecological interactions of the 6 introduced anoles found in the Miami area of South Florida; and some cool preliminary results from Kolbe suggesting adaptation in thermal tolerance in northern vs. southern populations of introduced Anolis sagrei in Florida. We also saw several talks on the evolution and genetics of development in Anolis, including a genuinely fascinating study (and I'm not usually fascinated by such studies, so this is no small compliment) by Doug Menke showing the association of a deletion in the Tbx4 hindlimb enhancer and "short-limbedness" among anole species. To my knowledge, this is the first study to potentially identify a explicit genetic variant responsible for the quantitative difference in limb lengths among anoles. This afternoon we heard from Joel McGlothlin, a post-doc with Butch Brodie at the University of Virginia, who presented results showing that genetic constraint in the form of the G-matrix is quite conserved among anole species; and from Luke Mahler, a present Losos graduate student, who is examining the relationship between niche availability and the rate of phenotypic evolution in Caribbean Anolis. If recent history can be used as a guide, there should be only 3653 days (and counting) until the next edition of the Anolis symposium. . . . I'll be there!
Saturday, October 3, 2009
The Museum of Comparative Zoology at Harvard University is presently (Oct. 2-4) hosting the 4th edition of the "Anolis Symposium," the definitive international meeeting of Anolis biologists worldwide. This edition, my first, seems particularly poignant as it has been accompanied by a dedication of the MCZ Herpetology Library to esteemed former herpetology curator and grandfather to the study of Anolis lizards, Ernest Williams. As a consequence the meeting has been so far highlighted by a series of informal speeches by a prestigious list of former Williams students at last night's dinner. These include, but are not limited to Paul Hertz, Ray Huey, George Gorman, Bob Holt, Richard Etheridge, and (as an undergraduate student in the 1980s), my former advisor, Jonathan Losos. Talk highlights of the day include prominent theoretical ecologist Bob Holt's "aesthetically impaired" but fascinating talk relating his graduate work under Williams in the 1970s on the introduced species pair of Anolis aenus and A. trinitatis on Trinadad; as well as an immensely entertaining talk by Manuel Leal on homing in Anolis gundlachi (evidently they do it very well, but we don't know how!). At right is a picture featuring Steve Poe's opening slide (in the upper panel), and me blogging about Steve Poe's fascinating talk (in the lower panel).
Thursday, October 1, 2009
In this week's PLoS One, Ewan Wolff and colleagues present evidence that a common parasite of birds, Trichomonas, also infected tyrannosaurid dinosaurs, and may have caused several, including the Field Museum's famous "Sue" to have died of starvation. The authors examined 61 tyrannosaurid specimens and found mandibular lesions in 10 of these that were consistent with similar lesions that are observed in modern-day birds that are infected with these parasites. Today, columbiforms are heavily parasitized by Trichomonas gallinae and these birds are likely the source of infection in raptors when they are consumed as prey (if anyone wants a live demonstration of this, come hang out in my office and watch the red-tails pick off pigeons). Wolff et al. argue that although infection via consumption of Trichomonas-laden prey can certainly not be ruled out, many of the specimens that show the lesions also have evidence of bite wounds on their heads, suggesting that face-to-face transmission may be the bigger culprit. While looking up information on T. gallinae, I also came across an interesting article in the Journal of Parasitology from last year that conducted molecular studies of Trichomonas isolates from doves around the U.S. using the parasites' ITS1, 18S and alpha-tubulin genes. The surprise of that paper was that the isolates from doves generally fell into two distinct clades - one similar to T. gallinae, but others that were genetically similar to the human STD, T. vaginalis! Clearly, more sampling of trichomonads should be done as they may play significant roles in the ecology of avian communities...and, as Wolff et al. suggest, may have even been having large impacts on birds' dino ancestors.