Last week I wrote about Ian Shive and the Wild Life team visiting my field sites in South Miami. Today, Ian has posted a couple of still images from the shoot. Go to GenerationWild.tv to check it out! And don’t forget to check back on April 18, when Wild Collective will be launching the pilot episode of Wild Life exclusively online!
It’s Friday again, and that means it’s time for some “Good Stuff of the Week.”
As a scientist, personal financial security usually comes in the form of a tenure-track position at a university. Even then, many modern tenure agreements include a “this is not a guarantee of a salary” clause – scientists need to keep bringing in grant money to keep getting paid. Science outside of institutions is definitely a road less traveled, but some manage to make it work. One marine biologist, Wallace J. Nichols, is using a novel strategy to fund his work: through his 100 Blue Angels project, Nichols crowdsources monthly contributions from dozens of backers to pay his salary and keep his research going. You can read more about it here. Cool idea, Wallace! Now, to find some financial backers of my own…
This next piece is really neither here nor there, but it’s too cool to ignore. Flapping flight is complicated, and I’ve never seen a machine that looks as genuinely graceful and, well, biological as this one.
Ever wonder why some Facebook posts and tweets get lots of attention, and others none? Certainly content has something to do with it, but timing is important too. This short article at the Nieman Lab of Harvard University dissects a huge analysis of Facebook posts, tweets, and e-mail newsletters, and suggests ways that better timing can make your social media strategy more effective.
Speaking of alternatives to the tenure track, have you ever wondered where the science comes from in shows like Bones, House, or CSI? Have you thought it might be a good idea to become a science consultant for the entertainment industry? Yeah, me neither. Still, I enjoyed this article by Jennifer Ouellette about how science consulting works. It’s an interesting look inside the entertainment industry, and provides some insight into the process by which science becomes part of our pop culture.
I’ve thought a lot about the connection between art and science. And while I generally find it easy to come up with examples of how science has contributed to art, it’s more difficult for me to come up with examples of how art contributes to science. Surely art can serve as a medium for communicating about science, but is this the only way science benefits from art? Nope. And this short article should convince you — it gives lots of great examples of the ways that art and artists have inspired scientists and engineers.
As much as I enjoy working with anoles, I’ve got to take a break from them once in a while. Luckily, I had a great opportunity last weekend to go shooting with two of South Florida’s best nature photographers. I got up early on Sunday and headed to Big Cypress National Preserve with photographers Mac Stone and Paul Marcellini, and local kayaking guide Garl (last name unimportant). Our objective was to find a couple of small lakes that Mac and Paul had only seen in satellite images. Big Cypress is about as dry as it gets right now, so a lot of wildlife would gather around the few remaining bodies of water. As we arrived at the Preserve parking area, I could already see that we were in for a good day – a few big alligators were bellowing right in the drainage ditches on the side of the road!
After hiking a few miles off the highway, and with a bit of help from the GPSes in our phones, we found the first lake. We emerged from dense swamp forest into a primeval-looking scene – in the early morning light, hundreds of alligators were crowded into a small lake surrounded by pond apples and dense blooming alligator flag. Herons and egrets were everywhere, and a bit of movement on the far shore alerted us to the presence of much larger game: a large adult black bear (Ursus americanus)! Bears are always present but seldom seen in the area – no one in our group had ever seen a bear in South Florida before. Unfortunately, once alerted to our presence, it ambled off, only giving Mac and Garl a chance for some distant “rump shots.” Still, it was a great way to start our day!
As we followed the tail-dragging tracks of alligators through a beautiful cypress strand toward a second lake, Mac spotted nearly stepped on a gorgeous water moccasin (Agkistrodon piscivorus). We photographed it (carefully!) and let it go about its business. I focused on closeups, but for a different interpretation than mine, you can see Paul’s beautiful wide-angle portrait of the snake here. We found the second lake around midday. As we rested in the shade and ate our lunch, the alligators crowded into the pond were trying to catch a midday meal of their own. You see, fish get concentrated into these small lakes, just like the gators do, and the gators have a technique for hunting fish in shallow water: they leap out of the water, turn their heads sideways, and crash down onto their prey. We had a blast trying to capture this behavior, and you can see one lunge captured in the photo sequence below. One thing I didn’t notice this until examining the photos on my computer is that when the gator hits the water, hundreds of tiny fish scatter in every direction, many of them leaping out of the water!
En route to the third and final lake, we ran across a small “gator hole” containing a brood of baby alligators, each no longer than my hand! As much as I wanted to get a closer look, the thick black mud surrounding the pool, and the possibility of the mother’s return, dissuaded me. The last place you want to be when an irate mother gator storms out of the brush is stuck in thigh-deep mud next to her babies! Nearby, we found a little Eastern Narrowmouth Toad (Gastrophryne carolinensis) – my first ever sighting of this species.
Throughout our swamp trek, we made our way through some spectacular stands of bald cypress and pond apple. Surrounded by abundant plant life in the densely shaded understory, the heavy air filled with the songs of Northern Parulas, White-eyed Vireos, and the occasional Barred Owl, I really got a sense of what all of South Florida must have been like before the landscape bore the scars of human exploitation. Big Cypress National Preserve is truly a remarkable piece of Florida’s natural heritage, and I can’t wait to explore it further.
I just returned to Los Angeles from two weeks of fieldwork in Miami. You’ve already heard about one of my adventures, but most of my fieldwork isn’t quite so glamorous! Instead of fishing for lizards with celebrities, imagine long days in the muggy heat of Miami, catching dozens of lizards and getting pooped on by most of them.
Last year at this time, I was dismayed to find that one of my study species, the Puerto Rican crested anole (Anolis cristatellus) was largely absent from the areas where I had expected to find it. This was a problem for me, since I study the interactions between the crested anole and another non-native, the Cuban brown anole (A. sagrei). Initially, my fear was that the dramatic cold snap that occurred early in 2010 might have wiped out one of my two study species!
Luckily for me, however, I was finding plenty of crested anoles by mid-May, so I began to suspect that crested anoles simply became active later in the season than brown anoles. If so, this could provide an interesting opportunity: I could test whether brown anoles exploited the available habitat differently before and after the “emergence” of crested anoles. Data from this natural experiment could help me understand how (and if) the two species were competing.
Of course, field research never goes quite as planned, and when I returned in April this year, the crested anoles were actually very active! The suppressed or delayed crested anole activity that I observed last year might have just been a fluke, brought on by the unusually cold winter.
But because fieldwork is full of unexpected turns, I had a backup plan for this visit. I wanted lay the groundwork for a large experiment I’ll be running this summer. In this experiment, I’ll basically try to accomplish what the cold winter of 2010 did for me: I’ll remove all the individuals of one species from an area, and observe the effects of this removal treatment on the remaining species. And unlike the cold snap of 2010, I can control which species are removed from different plots of land.
A critical part of this experiment is having a marked population of lizards. I’m focusing on males, because they defend territories aggressively against other males (and I’m interested in territoriality, among other things). So my goal on this trip was to find a site appropriate for my removal experiment – an area with approximately equal numbers of brown and crested anoles – and to mark as many males as I could. I settled on a roughly 500-meter stretch of canal-side parkland in South Miami.
In my previous experiments, I’ve never needed males to be marked for more than a few days at a time. So I could just use a paint pen to give each male a unique number – a male would lose this marking when he shed his skin, but generally I was finished with him before that happened. For this summer’s experiment, however, I need markings that will remain identifiable for much longer. Nate showed me a technique that he’s used for identifying his Podarcis lizards in Spain: using a loop of surgical suture, Nate attaches a series of colored beads to the base of each lizard’s tail. Like the colored leg bands often used to identify birds, the sequence of colors in this bead marking will serve to identify each male. With a few small modifications, Nate’s technique worked great with anoles!
Over the course of about a week, I marked 133 male anoles, and I managed to re-sight most of them in the same area where they were initially captured. The markings don’t seem to bother them in the least; I observed males performing all their usual behaviors, including copulating with females, in the days following their re-release. With any luck, I’ll be able to find most of these males again when I return in June, and there won’t be too many new individuals to mark! I know I didn’t get all the males in my study site, but I think I got most of them. And I should be in a good position to start my removal experiment in June!
I spent the last twelve days on the Spanish Mediterranean island of Formentera getting my field season started. This is my second summer here on Formentera and is my third year studying lizards in the Balearic islands. To find out more about the island, you can check out one of my first posts from last year (here). I thought it might be cool to start up regular video blogs from the field. This first one is a little long and boring, but they’ll get better as the season warms up and my experiments get underway!
The first entry of video blogging from the field in Formentera. More to come!
Remember the Gouldian Finch? I wrote about it a few months ago. Sarah Pryke, a behavioral ecologist at Macquarie University in Sydney, Australia has conducted some amazing research showing that female Gouldian Finches can control the sex ratio of their broods.
Now, there’s no denying that Gouldian finches are weird; males and females come in three head-color morphs, and this “sex ratio manipulation” comes into play only when a female is paired with a male bearing a different head color than her own – a situation in which the average fitness of male and female “mixed-morph” offspring differs dramatically. So, given all the peculiarities of the Gouldian Finch, is the manipulation of offspring sex ratio widespread among more “normal” birds?
A good strategy to address this question is to look for other situations in which the expected fitness of male and female offspring differ. Lincoln’s Sparrows, somber-toned residents of high-altitude and high-latitude breeding grounds in North America, provide just such an example. Male Lincoln’s Sparrows compete for mates using elaborate songs, and producing a high-quality song requires a certain bill shape. A deep, narrow bill allows males to produce a sexier song than does a wide, shallow bill.
As it turns out, the shape of a Lincoln’s Sparrow’s bill is related to its hatching date (the exact reason for this odd relationship is unclear). Chicks that hatch later in the season tend to have shallower, wider bills than those hatching early in the season. This holds true for both males and females, but females don’t need to sing to impress potential mates, so only late-hatching males suffer the cost of this seasonal shift in bill shape – when these males reach adulthood, their songs will be less attractive than those of earlier-hatching males.
Emily Graham and colleagues at UNC-Chapel Hill tested the hypothesis that Lincoln’s Sparrow parents manipulate the sex ratios of their broods based on their laying date. Later in the season, they predicted, broods ought to contain more female chicks. In a wild population of Lincoln’s Sparrows in Colorado, Graham and colleagues observed 35 nests and used genetic markers specific to the avian sex-determining chromosomes to identify the sex of each chick.
Sure enough, the later-laid clutches contained more female offspring. In fact, over a period of just 19 days from the earliest-laid to latest-laid clutches, the proportion of males in each brood declined from about 0.8 to about 0.4. This means that there were about twice as many male chicks per brood early in the breeding season as there were later in the season!
This study adds to the growing body of evidence that parents invest selectively in offspring of different sexes – they invest preferentially in male offspring when males are likely to have higher fitness, and in females when female offspring are likely to have higher fitness. The marked seasonality of sex-ratio bias in Lincoln’s Sparrows is an interesting wrinkle on this story. Seasonal variation in sex ratio is a clever solution to an evolutionary problem: what do you do when the complex relationship between the environment and the phenotype (i.e. the external, observable characteristics of an organism) causes a transient, but predictable difference in the fitness of male and female offspring?
What if the fitness of human males and females could be predicted by their date of birth? Loads of people (about a third of Americans, it turns out) believe that astrology is at least “sort of scientific,” so let’s all suspend our disbelief for a moment and imagine that people really have personality traits that can be predicted by the date of their birth. Some of these traits might affect reproductive success, and perhaps not equally for both sexes. For example, I am a Pisces. According to the Internet, this automatically qualifies me as “mysterious.” Does this characteristic make me irresistible to the opposite sex? Perhaps so.
But while my exaggerated level of mysteriousness makes me dreamy, a comparably mysterious woman might not gain the same reproductive advantage – maybe men don’t like mystery. In this case, natural selection would favor humans who tended to produce sons from February 19-March 20. You could test this hypothesis, as Graham and colleagues did, by examining hospital records and asking whether birth date predicted sex as predicted.
Of course, that test would be futile, because astrology is bogus. Sorry, 33% of Americans!
Graham, E., Caro, S., & Sockman, K. (2011). Change in offspring sex ratio over a very short season in Lincoln’s Sparrows: the potential role of bill development Journal of Field Ornithology, 82 (1), 44-51 DOI: 10.1111/j.1557-9263.2010.00306.x
Well, not quite. For one thing, when I’m doing fieldwork, my “office” is outdoors. And Sunday is supposed to be the one day a week when I don’t deal with anoles. Nevertheless, I headed to Matheson Hammock Park in South Miami on Sunday morning to catch lizards. But unlike my typical days in the field, I wasn’t alone. Instead, I met up with photographer Ian Shive, two well known TV actors (Stephen Colletti and Stuart Lafferty), and a small film crew.
Shive and his crew were in Florida filming a pilot for a new TV show, Wild Life: A New Generation of Wild. In Wild Life, which stars Colletti and the two Lafferty brothers (Stuart and his brother James, who couldn’t make it to the anole shoot), Shive wants to build the connection between people and nature, focusing on a younger generation of viewers. Young audiences already know the stars of Wild Life from their work on the series One Tree Hill. So as these TV role models explore some of America’s wild places, Shive hopes that kids and teens will realize that loving nature can be pretty cool.
My field sites in South Miami don’t quite count as “wild places,” but you can still find plenty of life even in small city parks. Stephen managed to noose a few anoles on his first try, which makes him better than some veteran anole researchers! We chatted about why I’m studying anoles, why we call them “invasive,” and why there are so many invasive species in South Florida.
All told, Shive and the Wild Life crew spent a week traveling all over Florida, visiting some spectacular places off the beaten track. I’m excited to see the finished pilot! (I’ll be sure to share as soon as I can.) I think using star power to sell young people on nature is a cool idea, and I really hope the Wild Life series takes off. Honestly, when it includes anoles, how can it fail?
Earlier this year Birder’s World magazine (now BirdWatching) ran my story about burrowing owl behavior and conservation. I was stoked to get the cover shot too! But at the time, I couldn’t share the whole article with my blog readers. Luckily, editor Matt Mendenhall just provided me with a PDF of the article, so now you can read it, complete with images, just as it appeared in the magazine. Don’t miss the awesome opening spread by my buddy Mac Stone (see below). Click here or on the image below to download the PDF. I’d love to know what you think!