Friday, June 19, 2015

Five-Lined Skink!

Last week was the end of the salamander field season in Northern Ohio; the high temperatures had driven most of the Plethodontid salamanders completely underground, rendering them nearly impossible to find. With the field season over, the lab-based part of my summer job is about to begin. I have a few days off before I have to head back down to Athens, and I've spent many of those days exploring (surprise surprise). One of the locations I've visited so far is Cedar Bog Nature Preserve in Champaign County, Ohio.

Cedar Bog Ohio
Cedar Bog is indescribable; it is by far one of the most amazing, and unique, places I've been to in Ohio. There are several different types of ecosystems located there, but this post takes place in the scene above. This is a White Cedar swamp. Swamps are essentially a forested wetland, and in this case the dominant tree is the White Cedar, a rare tree in Ohio.

Five-Lined Skink male
I was walking quietly down the boardwalk when a tiny scurrying noise caught my attention. I assumed it was probably a snake so I began searching intently for it. After a few seconds, I noticed a tiny head staring at me. It was a skink! I froze and hoped that he would possibly come out for a better view...

Five-Lined Skink, Plestiodon fasciatus
Sure enough, he did. This is a Five-Lined Skink, Plestiodon fasciatus. This specific individual, with his bright orange head, is a male in breeding colors. You might have heard of this skink by another common name, the Blue-Tailed Skink, which refers to the bright blue tail that the juveniles have. The Five-Lined Skink is the most common of the 5 lizard species we have in Ohio. I've previously covered another Ohio lizard on this blog, the Eastern Fence Lizard, which you can read about here. Although this species is the most common in Ohio, it isn't an easy find by any means. Skinks are incredibly fast (they're some of the fastest lizards out there), and any that might be in the area will simply run quickly away from you if you're not quiet and paying close attention. I would have never seen this guy had I not been looking and listening for anything that might be in the area.

Male Five-Lined Skink
Eventually the curious little skink wandered out onto the boardwalk only a few feet away from me. This was the start of a 10 to 15 minute game of hide-and-seek-with-a-skink. The skink would wander out into the open for a few seconds, then run away and hide. A few seconds later he would reemerge from a new location somewhere within 5 feet of me. This cycle repeated over and over. A ground-dwelling species, this skink knew all the ins-and-outs of his territory and could have easily slipped away never to be seen if he wanted to. It was an interesting encounter to watch unfold; he was obviously interested enough in me to check me out, and also seemed to know that I wasn't an immediate threat to him. He would have been gone had he seen me as a real threat, but instead he kept coming back and watching me.

Five-Lined Skink Cedar Bog
The Five-Lined Skink probably lives in most, if not all, of the counties in Ohio; however, only about half the counties have official records of this species, which can often be hard to find. Records of this species are conspicuously missing from the central part of Eastern Ohio. This is a common theme with many reptile and amphibian species of Ohio. Counties such as Belmont, Harrison, Jefferson, and others in that immediate area are missing records of many species that are almost certainly there. These counties must not be heavily explored by surveyors. Southern Ohio is still your best bet to see this species, as well as Cedar Bog NP in Western Ohio.

Thursday, June 4, 2015

Northern Parula

This year's Spring migration is all but a memory now, and most species are currently focusing on raising a successful brood. I, however, want to revisit a day during migration for this post. On May 19th I had the chance to visit the famous boardwalk at Magee Marsh along Lake Erie. Sadly, I was a few days late for the Biggest Week in Birding, but Spring migration was still hopping. I saw many warblers and assorted other migrants, but one Northern Parula gave me and a few other birders quite the show. I was fascinated by this Parula and decided to write up a post about the species, so here we go!

The Northern Parula, Setophaga americana, is a small migratory warbler. You might be wondering where in the world the name "Parula" came from. When this species was first classified by Carl Linnaeus in 1758, Linnaeus considered it to be related to the tits of the Old World. The name for this genus was Parus, and that was slightly changed to Parula for the common name of this species. However, the Northern Parula isn't a tit, and is instead a new world warbler. Like other neotropical warblers, the Parula spends half the year in more southerly climes and the other half in more northerly climes to breed. During Spring (April-May in Ohio), this species migrates from parts of Central America and the West Indies to the Eastern United States and Eastern Canada. It then spends the next few months trying to find a mate and raising a new generation before migrating back south to overwinter.

Northern Parula Magee Marsh
Where can you find this species in Ohio? Well, it depends on when you're looking. They can essentially be found anywhere across Ohio during migration, especially in the southern portion of Ohio and along the Lake Erie coast. It's a little harder to find this species during the Summer. They breed in the Allegheny Plateau region of Southern and Eastern Ohio, becoming scarcer the farther North you travel. The Northern Parula breeds in well-established forests here in Ohio. The older forests of Southern Ohio typically hold a good number of individuals. You can always find some in the Hocking Hills region, as well as Adams County. If you're looking for one though, good luck! The Northern Parula is a tree-top gleaner, meaning it feeds on insects that live on the branches in the canopy. Parulas are also roughly the same size as a chickadee. Spotting this tiny bird when it's 80 feet up in the leaves is definitely a frustratingly hard thing to accomplish. To help know when there's a Northern Parula near you, learn their song! It's a fairly easy song to learn, and you will find ten times more individuals this way than you would by just scanning the trees in hope for one. To listen to some examples of their songs, go to this link and look on the bottom right for "Songs and Calls."

Northern Parula Ohio
At Magee Marsh during Spring migration, things are a little different. Tree-top gleaners, such as the Northern Parula, might be only 5 feet off the ground. On top of that, the warblers are so focused on getting enough food to make it across Lake Erie that they essentially ignore all the people around. That means there might be a warbler only an arm's length away and right at eye level. Regardless of how cheesy it sounds, I can only describe Magee Marsh as a magical place, and birders who have made the trip know exactly what I'm talking about. This Northern Parula was no exception, foraging right at eye level only about 5 feet away. In the photo above you can see him checking out a leaf for a possible tasty arthropod morsel.

Northern Parula
And turns out there was indeed a tasty arthropod about! He quickly pulled a tiny green caterpillar off the leaf, which you can see in his beak above. As always, you can click on the photo to get a bigger version. While the Northern Parula eats a wide variety of arthropods, their favorites are caterpillars and spiders.

Northern Parula Eating
Another caterpillar victory!
If you look at a range map, like this one here, you might notice something strange. The Northern Parula nests in southeast Canada and the southeast US, but there's a noticeable gap where they don't breed. This gap separates the species into a northern and a southern breeding population. The gap is probably due to a combination of two main factors that I'll discuss below.

Northern Parula
The Northern Parula loves to make nests out of tree lichen. In the south they use Spanish Moss, which is actually a lichen, while in the north they utilize Usnea sp. lichens, commonly known as the Beard Lichens. Is there abundant tree lichen in the gap? Turns out there isn't, but that wasn't always the case. Lichen is very sensitive to air quality, and if you look at the gap you can see that it matches up nicely with big metropolitan areas where air pollution was, and still is, an issue. The Parula more than likely nested in the gap in the past before industrialization, but the air pollution the cities brought killed off the tree lichen species they would utilize. With the disappearance of appropriate nesting material, the Parulas were simply forced to leave that area; however, there is another factor to consider. Parulas favor complex forests where there is a variety in tree height, plant species, and so on. The area that the gap is in was a victim of deforestation, and as a result there is now a very homogenous forest instead of a complex heterogeneous forest. The homogenous, young forests of the area coupled with the lack of tree lichens is probably the true cause of the gap, not just one or the other. Once again, this is another example of human-caused problems. Hopefully the air quality will get better in the gap over the upcoming decades and the Northern Parula will once again return to the area to nest.