Friday, May 10, 2013

Flowers Flowers Everywhere

As part of my current job in the Midwest, I have gotten to hike the same 6 or so miles everyday since mid-March. This has been a great way to see how a whole forest landscape changes with the seasons. Because of the varied topography, geology, and forest types present, I have gotten to see a quite a variety of wildflowers as they come into bloom. Below are some of my favorites, enjoy! 






    
Woodland Phlox (Phlox divaricata divaricata)
A nectar source for butterflies and hummingbirds.

Fire Pink (Silene virginica)
Pollinated primarily by the Ruby-throated Hummingbird (Archilochus colubris)

Dutchman's Breeches (Dicentra cucullaria)
Seeds spread via myrmecochory--ants are specifically attracted by seeds and seeds are taken to the nest--providing both a food source for the ants and a rich soil for germination.

Jack-in-the-Pulpit (Arisaema triphyllum)
Contains oxalic acid which is poisonous. Used medicinally for sore eyes, rheumatism, and snakebites.

Showy Orchis (Galearis spectabilis)
Often called a hooded orchis due to the fact that the petals and flower are found
inside the purple and white sepals.

Bellwort/Merry Bells (Uvularia perfoliata)
Perfiolate, which means the leaves grow around the stem, a unique growth pattern.

Blue-eyed Mary (Collinsia verna)
One of the few wildflowers that exhibit a true blue color.

Yellow Lady's Slipper (Cypripedium parviflorum)
This orchid is threatened or endangered in many states.

White Trillium (Trillium grandiflorum)
A contester of Reid's Paradox, which states that plants could not have survived past glaciation if their seed dispersal is less than several hundred meters per year. Once again a flower that uses myrmecochory.

Have you found any favorite flowers in bloom yet? Depending on your latitude, there are still many flowers that have yet to bloom, so get outside and check it out. 

Monday, April 22, 2013

Twitterpated

Well, it's getting that time of year where all the animals are getting frisky. Many of the amphibians are waiting for their larvae to hatch, and some are in the race against time to metamorph for terrestrial life before their breeding pools dry up.

Now that it is getting warm enough for the reptiles to stir, their season of reptile love (and war) is starting to begin. In particular, I came upon a male Northern Fence Lizard (Sceloporus undulatus) trying to woo a female in courtship. Typically, fence lizards do push-ups to mark their territory and to signal that other lizards should stay away; however, in this case, there is a male and a female fence lizard present, so I am guessing it has more to do with that than anything else. For the fence lizards, mating season typically begins in April. On top of their macho push-up routine, males will also use a pheromone to attract a mate.

Maybe it is because I interrupted the process, but I don't think the female showed much interest. (For both videos, play in higher resolution).


Please forgive the disenchanting narration. My coworker called to tell me he
had found a snake.

In part to attract a female, but also to show how tough they are, males also have a bright blue coloration on their belly and neck. Thus, when the lizard conducts their push-up routine, the colors are flashed as the lizard goes up and down. One way to tell the difference between a male and female is that the blue color is much less intense on a female, and it often is less apparent on the neck. Below is the male, and from this angle you can see the blue much more vividly (The blue doesn't show up unless it is played on the higher resolution youtube setting).

If the mating is successful, the female will be in gestation for about eight weeks, after which she will lay the eggs under a few inches of soil. This will help regulate the temperature of the eggs. Depending on when the eggs are laid, they will hatch between June and September. The size of the female determines how many eggs are laid, and it ranges from 3-13 eggs per clutch. During the year, a mature female can have multiple clutches. Younger females (1 year-old), typically only have one clutch per year.

As these are a very common species, I'm sure you all have been seeing them moving about now that spring is here.

References
Adolph, S., W. Porter. 1996. Growth, Seasonality, and Lizard Life Histories: Age and Size at Maturity. Oikos, 77: 267-278.
Ferguson, G., C. Bohlen, P. Woolley. 1980. Sceloporus Undulatus: Comparative Life History and Regulation of a Kansas Population. Ecology, 61: 313-322.
Presidents and Fellows of Harvard College. 1983. Lizard Ecology. Cambridge, Massachusetts: Harvard University Press.

Wednesday, April 10, 2013

Odin to a Bobcat



He gave the orb of an eye to Mimir's Well,
and in return sound counsel bequeathed.
            My own eye watched,
            wrought of glass and wire,
Upon the bark of Yggdrasil it waited in steel sheathed.
On the path through the wood this avatar did tread.
The wanderer, Asgardian, the Allfather
            filled Midgard with dread,
yet this forest deity I did bother,
and now too I must search for an answer.
           

            Thank you for indulging my amateur attempt at the ode form of poetry. Also, please excuse the terrible pun titling this post.
            So you are probably asking, what is all the theatrics for? Well, at my new temporary playground in the Midwest, I have gotten an interesting set of pictures on my camera trap. Not too long ago, a one-eyed bobcat (Lynx rufus) made his way by my camera trap, and considering my the gadget had only been up two weeks, I was pretty ecstatic to see it! In my past experience, such camera-trap captures are infrequent to say the least.




            Bobcats are nothing new in North America. The oldest fossil they have of a bobcat ancestor is from 2.4-2.5 million years ago (Anderson & Lovallo, 2003). Even though the current distribution of the bobcat spans from coast to coast and from Canada down to Mexico, they have restricted ranges in certain states.
            Now I am not sure if the Odin bobcat I got a picture of is big or small, young or old. My guess is he is a male, though, and that arises from the fact it is breeding season, and females move significantly less than males (see Anderson & Lovallo, 2003). Either Odin has seen some battles and has successfully protected his territory from other cats, or he is down on his luck and has been fended off by some bigger males.
            It is also quite possible that I got pictures of two different cats. The photograph from the 24th looks a little more husky and large, yet when they are both nearest to the stem in the center they are around the same height. The individual from the 31st seems to have more spots on his legs. It's plausible that they are two different individuals. In terms of movement, adult bobcats can move over 2 km in a day (with a home range around 40 km^2 depending on region; see Anderson & Lovallo, 2003). When it comes to younger cats dispersing, it is not too uncommon for individuals to move more than a couple hundred kilometers in search of adequate habitat.



            Either way, it is a neat series of pictures. I would be interested to hear your thoughts.

Works Cited
            Anderson, E.M. & M.J. Lovallo. 'Bobcat and Lynx'. In Wild Mammals of North America: Biology, Management, and Conservation. Edited by G.A. Feldhamer, B.C. Thompson, and J.A. Chapman. John Hopkins University Press, Baltimore, MD: pp 758-788.

Wednesday, January 30, 2013

Torpor Affects Us All

Despite the unusually warm winter (2012 being the hottest year on record for the continental U.S.), even I succumbed to winter torpor. Good thing I stocked up some energy with all of the holiday treats!

Diverging from our small-mammal accounts from my time on the Eastern Shore of Virginia, I wanted to provide a quick glimpse at some of the herpetofauna I found while island hopping. It is surprising to think how these animals made it to the islands via saltwater (predators and dehydration) and how they have been able to survey on dynamic ecosystems that are constantly flooding and changing habitat types.



This Eastern Box turtle (Terrapene carolina carolina) was found on Smith Island, which is one of the southernmost barrier islands off of the Delmarva Peninsula. At it's closest point, the island is approximately 2.2 km from the mainland. That is a long way for a terrestrial turtle to go in a harsh environment. Given the number of storms that occur though, it is possible it got blown or swept there. Conant et al (1990) also hypothesized that the turtles might have been brought to the island when it was inhabited by humans up until the 1930s. It seems the population has been able to survive in the wooded areas.



I also came across a rather feisty Black Rat snake (Elaphe obsoleta now Pantherophis obsoletus) while on Mockhorn Island. Mockhorn and Smith occur close together, and the snakes have been documented on Smith Island in the past. Interestingly, this individual was sunbathing on a rather cold and cloudy day. Perhaps it had planned poorly, for it was stranded on a small tump of high ground during high tide. For an instant I expected it to ask for a Marsh Rice rat from one of the Sherman live-traps.



While doing surveys on the mainland, I was also able to glimpse this speedy Ground skink (Scincella lateralis)  "dancing" through the pine needles. These skinks are unusual in that they rarely climb, and they wriggle their body back and forth to move. They can grow up to five inches, so the one in my hand is not all that large.


Switching gears to our amphibian friends, I came across two frog species while working around the field station. The first (above) is a Green Tree frog (Hyla cinerea). The second (below) is a Southern Leopard frog (Lithobates sphenocephalus). The fun thing about the Green Tree frog was that I watched it turn from a bright green to the olive green you see in the picture. This may have been due to an effort to camouflage or because it moved from the sun to the shade. The Southern Leopard frog is simply a nice looking creature.


Sources
Conant, R., J.C. Mitchell, and C.A. Pague. Herpetofauna of the Virginia Barrier Islands. Virginia Journal of Science 41: 364-280.




Tuesday, November 6, 2012

No Floaties Required aka Mammal Profile Vol. 3: The Marsh Rice Rat

Despite Hurricane Sandy's best efforts, Eastern Shore of Virginia has survived the strong winds and the high waters. Power was only lost temporarily, and the flooding was minimal. To many this may be surprising, but the Virginian section of the Delmarva Peninsula still has many of its natural fortifications. Almost all of the barrier islands off the coast are wilderness, and there are expansive salt marshes between the shore and the islands--not to mention extensive oyster and shellfish beds. All of these reduce wave motion and act as a shield to hurricanes. This is a fine example of ecosystem services, processes which ecosystems perform that benefit humans.

Compared to Norway rats and black rats (the invasive beast and
the grungy city-dweller, respectively) The marsh rice rat is a rather handsome rodent.

But, the real reason we are here is because we want to learn about the robust, ever-versatile marsh rice rat (Oryzomys palustrus, "Marsh/Swamp Rice Mouse"). As it is semiaquatic, these mid-sized rodents flourish in marshes and the Atlantic coastal plains. Their distribution ranges from Texas through the Southeast and some parts of the Midwest, up to New Jersey.

Marsh, marsh edges, and the surrounding uplands all are likely
places to find this species. Here, my colleague J. Sparks works along
one of the trapping lines. 

As their name suggests, they are bountiful in all types of marshes (saltwater and freshwater), and are able to swim great distances, sometimes holding their breath underwater for long periods of time. The longest I have counted so far is 17 seconds. On the barrier island system they have been reported to swim distances greater than 50 meters across deep channels, no easy feat for an animal that is usually smaller than a soda can. Because they are a truly hardy species, the presence of the marsh rice rat is almost the "100% guarantee" of small mammal trapping on the barrier islands we are surveying. Even on islands that are constantly shifting or are barely an island at all, a rice rat will be present. Thus, they are important players in understanding biogeography, the discipline that tries to understand how populations of species vary and function over different landscapes.

After taking measurements, this guy went on a nice underwater swim and hid in the grasses.

Another rat wanted to demonstrate its swimming abilities for the camera. Given that water
causes rapid temperature loss, it is curious to think about how these rodents survive during
colder months after being submerged. It probably has significant energy consequences.

Marsh rice rats are true omnivores and will generally eat most things they come across: plants, seeds, snails, insects, fiddler crabs, mollusks, and some eggs of marsh-nesting birds. They also are an important food  for marsh hawks, owls, snakes, and mammalian predators such as fox and mink. Thankfully, they are not too much of a hassle for human beings. Because of their habitat preferences, they rarely infringe on human endeavors and become pests.

Unfortunately, these animals are quick, and this is the only natural picture I have been
able to capture. These species are also gutsy, inhabiting grassy dunes and making sprints
across open sand.

Sources
Linzey, D.W. 1998. The Mammals of Virginia. The McDonald & Woodward Publishing Company: Blacksburg, VA.
Moncreif, N.D. and R.D. Dueser. 1994. Island Hoppers. Virginia Explorer 10(4): 14-19.
Webster, WM. D., J.F. Parnell, and W.C. Biggs, Jr. Mammals of the Carolinas, Virginia, and Maryland. The University of North Carolina Press: Chapel Hill, NC.

Sunday, October 21, 2012

Mammal Profile Vol. 2: The White-footed Mouse

For those who do small mammal surveys, it is never unusual to get a white-footed mouse (Peromyscus leucopus, "Mouse with White-Footed Boots"). Both the white-footed mouse and its close relative the deer mouse (Peromyscus maniculatus "Agile Mouse with Boots") are the most populous mammals in North America. So, while they might not be the most exotic species to capture, they certainly play an important role in ecosystems.

White-footed mice are skilled climbers, sometimes caching food or making nests in
tree hollows. Here, a mouse avoids be weighed by climbing the Pesola scale.

Interestingly, the white-footed mouse has not colonized many of the barrier islands off the Eastern Shore, with the exception of four islands (Assateague, Wallops, Cedar, and Fishermans; Moncreif and Dueser, 1994). While there is certainly great habitat for them, they have not been documented on any of the other islands. This is surprising, as P. leucopus has great homing abilities and has well documented swimming abilities. It could be that the intercoastal water conditions are too prohibitive.


There is no scientific merit to this picture, except that the mouse looks funny while
trying to bite the Pesola scale so that it can escape. Actually, wriggling and biting, besides their speed,
is their only defense once captured by predators.

White-footed mice have also have become a public issue these days. Whether it is because of a change in predators, climate, or habitat composition, white-footed mice have come under increasing attention due to the higher incidence of Lyme disease and hantavirus--both of which they are carriers of. Even though their higher densities equate to human health concerns, the mice play an important role in linking food webs, as they their omnivorous diets are transferred to larger predators like foxes, bobcats and raptors (many of whom consume large amounts of the rodents). Economically speaking, mice consume large numbers of seeds from weed plants as well as insects and generally avoid cultivated areas. Despite this, the wildlife disease consequences of their current success is a central facet of current research.

This species favors hardwood forests as well as the edges of forests and fields. On the shore, they are found in myrtle shrublands and marshes. While typically not hallmarked for their presence in coastal areas, they also seem to abound in drier mixed hardwood-pine forests.



Sources:
Linzey, D.W. 1998. The Mammals of Virginia. The McDonald & Woodward Publishing Company: Blacksburg, VA.
Moncreif, N.D. and R.D. Dueser. 1994. Island Hoppers. Virginia Explorer 10(4): 14-19.
Webster, WM. D., J.F. Parnell, and W.C. Biggs, Jr. Mammals of the Carolinas, Virginia, and Maryland. The University of North Carolina Press: Chapel Hill, NC.

Saturday, October 6, 2012

Mammal Profile Vol. 1: The Least Shrew

Whum chakka um chakka chumchakka whum!
Guosim dig yore paddle deep,
Hurly-burly river wide'n'curly,
There's no time to sleep.
Whum chakka um chakka chumchakka whum!
Rapid wild and fast do go,
Hurly-burly river wide'n'curly,
Bend yore backs an' row.
Whum chakka um chakka chumchakka whum!
Keep her bows up in the foam,
Hurly-burly river wide'n'curly,
Logboat take us home.
Whum chakka um chakka chumchakka ...


-Paddling Song, Guerrilla Union of Shrews In Mossflower, Marlfox by Brian Jacques

I'm not sure if you have read any of the books in the Redwall series by Brian Jacques, but as the main characters are mostly small mammals, you can bet I will shamelessly make references to the series during these mammal profiles (If you haven't heard of the series, it is similar to Watership Down).

So far during our trapping endeavors, we have captured 5 different species of small mammals. One of my favorites, the least shrew (Cryptotis parva, Greek and Latin for "small hidden-ear" shrew), is the first animal I'm going to discuss. The least shrew is in the diverse and complicated order Insectivora (insect-eating and carnivorous mammals). Within that order, they are classified in the Soricidae (shrew) family, a group containing some of the smallest mammals. Characterized by their small eyes, pointed teeth, and long tapered snout, this species relies mostly on its sense of smell and hearing to move and locate prey.

Least shrews are very vocal, using clicks and squeaks to communicate.
In this case, they are mostly communicating, "Stop weighing me and let me go."

The mammals are very small, growing up to 92 mm in length--including tail--and weighing up to 5.7 grams, the weight of a nickel. Although small, they are voracious eaters and busy critters. They are almost always active and only have short periods of rest. Part of this arises from an incredible metabolism: having to eat 50% of their weight or more every 24 hours. The least shrew consumes large amounts of arthropods, worms, and other insects. For some insects that are too large to consume whole, the shrew will eat out the insides. They also are a food source for many other animals, including snakes, raptors, foxes, and skunks.

While the least shrew is often confused with members of the short-tailed shrew genus (Blarina), the least shrew is distinguishable by its tail, which is less than half the length of its body and head. Behaviorally, the least shrew also is rather social, as nests can have up to two dozen individuals. These nests are usually found near logs, rocks, and debris, and they are made out of shredded grass and leaves.

 Unfortunately, due to their energetics, it is not rare to have shrew mortality.
Sometimes the shrew cannot survive the time in the trap, but all possible measures are taken to avoid it.

The old-field habitat in which we surveyed and found the majority
of our least shrews.

The least shrew is mostly found in dry, open grasslands, but they also are found in saltwater marshes.  Typically, the Sherman live trap is not the best method to capture shrews, but we set the trap's trigger to close at a lighter weight.

Sources:
Linzey, D.W. 1998. The Mammals of Virginia. The McDonald & Woodward Publishing Company: Blacksburg, VA.
Webster, WM. D., J.F. Parnell, and W.C. Biggs, Jr. Mammals of the Carolinas, Virginia, and Maryland. The University of  North Carolina Press: Chapel Hill, NC.
Schemnitz, S.D., 2005. Capturing and Handling Wild Animals. In C. Braun (Ed.).Techniques for Wildlife Investigations and  Management (pp.239-285). Sixth Edition. The Wildlife Society: Bethesda, MD.