Monthly Archives: March 2014

Bat Evolution

What is a bat? From a human perspective, they are easy to recognize: little flying rodents that come out at night. Bats are the largest mammalian order after rodents, with 966 different identified species (Altringham 1996). Together, this one order comprises one-quarter of all known mammal species. They range in size from the bumblebee bat (the smallest known mammal at 1.5-2g) to the 1kg flying fox, which has a wingspan of 1.5m.

From an evolutionary standpoint, however, the truth is much more complicated. Currently, all of what we know to be “bats” are grouped in one order, chiroptera. Animals within this order are the only known mammals that can sustain flight (mammals such as flying squirrels can only glide.) Within this order are two subgroups mega- and microchiroptera, frequently called mega- and micro-bats. Mega-bats are found only in old-world locales and are exclusively plant-eating. Micro-bats are much more widespread, inhabiting every continent except Antarctica, and also have a more varied diet. Because of their similar physiology, these two groups of bats were classified as subgroups of the same origin but recent evolutionary evidence is casting doubt on this assumption.

Bumblebee Bat

There is very little fossil evidence remaining of ancient bats, possibly because of their light bone structure.  The oldest bat fossil was found in Yellowstone National Park and dates to around 50 million years ago.  Genetically, they are not very closely related to any mammalian order except sloths and anteaters, neither of which is very different from their ancient ancestors.  Scientists have therefore had to rely heavily on genetic and physiological analysis to try to understand bats’ evolutionary history (Altringham 1996).  They speculate that early bats probably got around by jumping or gliding, much in the same way as the modern flying squirrel.  They evolved to hunt at night to avoid predators and other more adept flyers such as birds, and fed on flowers to avoid competing with them for food.  Eventually, the skin membranes that enabled them to glide evolved into wings, allowing them to sustain flight.  Based on analysis of the cochlear cavities of ancient bats, scientists believe that their ability to echolocate evolved alongside flight.

Flying Foxes

Mega-bats are generally much larger than their micro-bat cousins.  They are found only in very specific regions around the equator in areas that produce enough vegetable matter to sustain them, such as the Amazon rainforest, the Congo, and the Indonesian islands.  Their strict vegetarian diet is not the only thing that differentiates them from micro-bats; they also do not echolocate.  There are many more species of micro-bats (around 700) than mega-bats (around 300).  It has always been puzzling to scientists why mega-bats’ range is so confined and why, if they are so closely related to micro-bats, they are exclusively vegetarian and cannot echolocate (Fink 2007).  Scientists are now beginning to piece together an alternate evolutionary history of these mammals: instead of the two subgroups evolving from a common ancestor, they now believe that micro-bats evolved millions of years before mega-bats.  This explains the preponderance of species, difference in diet, and echolocating ability, but it does not explain their almost identical physiology.  However, recent studies of modern bat skeletons have shown a significant difference in the ratios of finger bones to forearm length in mega- and micro-bats causing scientists to rethink whether these two subgroups are related at all.  (Altringham 1996) Some are now entertaining the idea that these two orders evolved entirely independently of one another and somehow achieved an almost identical physiology.

What constitutes a “bat” is much more complicated than what once had been assumed, the order chiroptera may not be an adequate classification.  Although it is convenient to keep them together, the truth is not as straightforward.

Works Cited

Altringham, John D. Bats : Biology and Behaviour. Oxford [England]: Oxford University Press, 1996.

Fink, Patrick. “Echolocation in Microchiroptera.” Reed College, 2007. Web. 28 Feb. 2014.

Post by Luke Gates, Fourth-Year, Architecture

Nocturnal Team Update

The nocturnal BioGrounds team now has a total of five cameras. On March 7th before spring break, team members set up 3 of the 5 cameras.

The goal of this project is to understand and observe animal activities at night therefore location is crucial when setting up the motion detectors. Our team members decided to place the cameras at 3 distinct locations on grounds: dumpsters behind Lambeth, the Observatory Hill and the garden behind the lawn. Dumpsters behind Lambeth provide continuous food supply and shelter to stray animals e.g. cats, raccoons and skunks. These creatures will frequently visit dumpster sites to search for food. In cold, unpleasant weather, animals may also temporarily hide in dumpsters to stay warm. Animals prefer places where there are few human activities, therefore, our team members placed the second camera at the Observatory Hill located far away from all dorms and academic buildings. Observatory hill is also surrounded by trees and bushes thus serve as good hide out or homes for creatures where they can feel more comfortable. The third camera is placed in the gardens behind the lawn. These gardens are frequently visited by birds and squirrels and may also attract raccoons from time to time since it is located away from the roads.

The cameras are strapped to trees or lampposts at around 1.5 to 1.8 meters above ground. This gives the camera a wider view and increases the probability of capturing more animal movements. When setting up the camera, team members have to make sure not to face the lenses directly east or west. Direct sunlight entering the lenses can burn and destroy the camera. Once the camera is secured, the switch is turned to manual. When motion is detected, the camera will automatically take three pictures of the moving object and save it to internal storage.

Camera strapped to a tree located in one of the gardens behind the lawn.
Camera strapped to a tree located in one of the gardens behind the lawn.

Post by Linda Chen, Third-Year, Environmental Sciences

The Visiting Great Blue Heron of the Dell Pond

In the next few months of the Cities + Nature BioGrounds project, the students of the BioGrounds Bird Team (General) will be taking turns highlighting a species of bird that we have identified somewhere on Grounds. This week, I will be showcasing the Great Blue Heron that quite often visits the Dell Pond at UVA.

Photo by Samantha Taggart

A Great Blue Heron is a remarkable creature to behold. I have spotted one twice now, visiting the Dell Pond. The first time I noticed a heron at the Dell was last Fall, when a briskness was just beginning to touch the early autumn air. The heron’s fixed, pointed gaze and cautious, calculated slow movements seemed to perfectly match the crisp, clear air signaling the coming of the cold. I found myself a sun-drenched rock to sit upon and studied the heron for what seemed like hours (in actuality it was probably just a few minutes). The heron didn’t move, it stood poised, still as a statue, until in one fell swoop its razor sharp beak darted down to catch a fish. It swallowed the fish in one gulp.


The heron stands in water where the swamp
Has deepened to the blackness of a pool,
Or balances with one leg on a hump
Of marsh grass heaped above a muskrat hole.

He walks the shallow with an antic grace.
The great feet break the ridges of the sand,
The long eye notes the minnow’s hiding place.
His beak is quicker than a human hand.

He jerks a frog across his bony lip,
Then points his heavy bill above the wood.
The wide wings flap but once to lift him up.
A single ripple starts from where he stood.

—Theodore Roethke (1908-1963)


Photo by Samantha Taggart

You may be wondering, “what is a great blue heron doing this far from the coast?” I was wondering the same thing. Apparently the habitat and hunting grounds of the great blue heron is not restricted to the coastlines of the ocean, but also includes marshes as well as the shores of freshwater ponds and streams. Also unknown to me was the fact that although herons typically hunt alone, they normally nest in colonies. In addition to eating many aquatic species including fish, eels, shellfish, and aquatic insects, these carnivorous birds also consume small mammals, reptiles, amphibians, and even small birds. In fact, it is not uncommon for a heron to choke to death because it’s attempted to swallow a creature that was too big for its long S-shaped neck.1

Photo by Samantha Taggart

If you’ve never seen a great blue heron, they’re huge! Their height (3.2-4.5 feet) and wingspan (5.5-6.6 feet) make them quite a stunning creature to witness in flight.  They typically fly between 20 and 30 miles per hour.1

Contrary to their breathtaking physical features, the great blue heron has a call that would make anyone want to put earplugs in immediately.

Rather than trying to describe the cacophonous calls of the great blue heron to you, I’ll let you listen to them for yourself…


I’d like to end with a question posed to another fellow BioGrounds Team – the Aquatic Life Team. My question is: what sorts of aquatic species are attracting this great blue heron to the Dell? Is the Dell teeming with all sorts of reptile, amphibian, and fish species that the heron finds simply irresistible? And what about this time of year – is there anything alive in there?

Referenced Materials:



Post by Samantha Taggart, Fourth-Year, Environmental Thought and Practice

Green Roof or Greenery on a Roof? What Defines a Green Roof?

As our group prepared to take on the task of cataloging the biodiversity found on green roofs around the University of Virginia, we were faced with an initial uncertainty- what defines a green roof? In particular, we asked ourselves what distinguishes a green roof from greenery on a roof? After further research on the topic, it is obvious that there is no quintessential prototype of a green roof.

Green roofs, sometimes referred to as “living roofs,” are growing in popularity and abundance in urban environments. Their manifestation varies significantly from continuous roof-spanning versions, to modular greenery and potted plants, to even rooftop ponds that serve to treat greywater. In general, a typical green roof is composed of vegetation growing over a weatherproof membrane. Additional root-protective layers and irrigation systems are sometimes incorporated as well.

While the appearance and structure of green roofs can be diverse, the accompanying ecosystem services are universal. These benefits can be broken down into three main groupings: environmental, economic, and aesthetic benefits. Green roofs provide an added habitat to otherwise barren urban environments. Plants have the ability to filter pollutants from the atmosphere, which improves local air quality. Vegetation can also serve in storm water retention, providing additional environmental benefits. Green roofs have a cooling effect that helps to combat the urban heat island effect. They provide enhanced insulation to buildings, which saves heating and cooling energy, therefore saving money. Green roofs also protect the actual roof surface and may increase the longevity of the structure. This saves money from being spent on maintenance and replacement. The aesthetic benefits of green roofs are not negligible either. In class, we have discussed the numerous health benefits humans receive from being in close contact with nature. Studies have shown that greenery is beneficial to our mind, body, and spirit.

In early February, our team decided to check out our first green roof at the University of Virginia. We visited Ruth Caplin Theatre, one of the university’s drama buildings. There, a grassy hills gently slopes upward and levels off at the rooftop of the theater. On the roof we found multiple plant species, a mix of hard concrete surfaces and vegetation, and they appeared to be utilizing a drip irrigation system. Overall, this green roof is highly accessible.

On top of Ruth Caplin Theatre
View of the green roof from the Arts Quad
A combination of concrete and vegetation
A combination of concrete and vegetation

Over the course of the semester our team plans to visit multiple green roofs around grounds, meet with UVA Facilities Management, as well as interview the architect to discuss his intentions in implementing green rooftop infrastructure in his design.

Post by Cara Pattullo, Fourth-Year, Environmental Science

Tree and Forest Team

As we walk around grounds, our focus is usually centered on getting from one place to the next. However, as the landscape changes with every season, we often admire the beauty of nature by spending more time outside. There are over a thousand trees at U.Va. and although we appreciate the aesthetic value of these trees, the average student probably has little knowledge of the history, let alone can name or identify the various tree species that exist on grounds. In our first blog post, the Tree and Forest team will provide historical facts so the reader has some general information that he or she can use for future reference. 

In a 2008 article entitled “Deep Rooted” (U.Va. Magazine), Mary Hughes (University landscape architect) identifies a few key facts about trees at U.Va. For example, the first trees were black locust trees but none of these original trees still exist on grounds. The oldest trees are the sycamores on the north side of the Rotunda, which were planted before the Civil War. Around this same time, the University planted the Pratt Gingko on the west side of the Rotunda. The Gingko was planted in honor of William Pratt and is considered the first official memorial tree.

The picturesque Pratt Gingko. Photo by Robert Llewellyn for “Deep Rooted” article in U.Va. Magazine.

Since 1970, U.Va. has made it a tradition to plant a tree to honor an individual who has made a lasting impact on the University. This annual ceremony, which is presided over by the University President, occurs on Founder’s Day and is organized by the Arboretum and Landscape Committee. In addition to this official tradition, U.Va.’s memorial and commemorative tree program allows private individuals the opportunity to fund the planting of a tree in honor of an individual connected to the University. Overall, these trees are intended to serve as “living memorials” to significant members of the U.Va. community.

The most recent “officially designated” tree honors John Casteen, the President of U.Va. from 1990-2010. The American Linden is located in the Arts Quadrangle between the Drama building and Ruffin Hall. Photo from

Officially designated trees and the private commemorative trees are planted in various locations around central grounds. However, only a handful of trees on the upper and lower lawn are commemorative. Regardless, every tree on the lawn, whether commemorative or non-commemorative, belongs to either the ash or maple tree family (around 80 percent are ash). After the black locust trees died off, they were replaced with hardwoods that were taller, long lasting, and could provide more shade. While sugar maple, green ash, purple ash, rosehill ash, and pumpkin ash populate the upper lawn, the lower lawn largely consists of sugar maple and white ash trees.

In light of the renovations around grounds, many people have raised concerns about how to incorporate trees into the changing landscape. Trees are often viewed as barriers to new construction and, unfortunately, one way to deal with the barrier is to remove it. Recently, the magnolia trees surrounding the Rotunda were removed despite fervent pleas to save them. However, the magnolias were damaging the underground sewer lines and proposed a risk to the building itself. On the other hand, the South Lawn project (completed in 2010) provided a blank canvas for landscaping. The proposed height of the buildings meant that larger trees were needed in order to ensure that the complex wouldn’t appear too overwhelming to pedestrians. In addition to the popular ash or maple, some of the intended tree species to be planted included the willow oak and European beech. Large trees were strategically planted to maximize building shade in the summer and capitalize on sunlight in the winter. By emphasizing the importance of tree preservation and growth, the landscape design plan for the South Lawn increased the overall energy efficiency of the buildings.

Overall, the value of trees extends beyond their beauty; trees add character to the University. Although this post only focuses on the history of trees on grounds, we intend to provide more detailed findings as the semester progresses.

Post by Lisa Zimmerman, Fourth-Year, American Government

Wildlife of Your Dorm

After meeting a couple of times, our group has begun to formulate a plan as how to gain a better understanding of the interior microbial life across UVA’s Grounds. Despite constantly being in the places we hope to collect samples from, few, if any, people at UVA have knowledge of the microbial life that is around us throughout our days. Our inquiry into the indoor microscopic life of UVA was partially motivated by a project conducted by Professor Robert Dunn of North Carolina State University called The Wild Life of Our Homes. The main premise behind his project is that there is an invisible ecosystem within our homes. While Professor Dunn’s project used around 1,000 samples sent in from homes across North America, a project on this scale may not be feasible in the time we have with the resources we have.

One idea that we have come up with as a group is to collect samples from various living situations, both on-Grounds dorms and off-Grounds apartments and houses. Ideally, the dorm room samples would be collected in male and female rooms from both new dorms and old dorms. Comparing the microbiology of school maintained dorms with the student maintained apartments and houses could prove to be fairly interesting (Can college students really clean their living space?). One of the problems that may arise, however, is accessing all of the buildings and rooms in which we would want to take samples. It can be done but would most likely require coordination with resident staff and students living in those rooms.

Another idea that was actually brought up by Professor Timothy Beatley was that our team could collect samples in the libraries on Grounds. He was fairly open ended about the idea, but after thinking about it, the amount and types of people that study on each floor of each of the main libraries varies quite a bit. This plan takes less pre-planning than going to dorms and apartments. The drawbacks to this idea include the possibility that because a high volume of people frequent all the libraries that there would not be much variance in the microbiology.

Moving forward, we hope to meet and speak with Rob Dunn during his visit to UVA. We hope that he will be able to provide insight into which of our ideas he prefers or whether he has a different idea entirely. Our current goal is to get started with the sampling shortly after meeting with Professor Dunn. And as stated in the beginning, hopefully we shed light on the indoor wildlife of our university.

Post by Gregory Waldrip, Second-Year, Systems and Information Engineering

Nightlife at UVa, and we’re not speaking of the Corner

The job of the Nocturnal Life team is to gather information on the animals that can be found on UVa grounds at night. The nocturnal fauna is more diverse and numerous than most people think; indeed, it is easy to miss it, because it’s most active at times when humans sleep (or stay inside) and because as diurnal creatures, we’re not very good at seeing what happens in the dark. And yet, a lot happens. Some signs might be found in the morning by those who know what to look for: tracks, animal waste, etc. Studying the nocturnal fauna of our University brings us a new insight on the vast biodiversity of grounds and the complexity of the ecosystem we live in.

Our goal is to accumulate data on what animals go out at night, and to determinate where and when they might be found. The best way for us to do so is by taking pictures of animals at night using camera traps. These are special cameras meant to be disposed outside (they’re waterproof, have a long battery life etc.). They have “night vision” – meaning they can take pictures in the dark – and are movement-activated. So basically, the idea is just to place them in a strategic place, wait for an animal to walk in front of them and come get the photos in the morning. As I’m writing this blog post, we haven’t received the cameras yet. The University has promised us five of them, and we should start taking pictures in the next few days. What we have done right now is set up our plan of action and methodology.


Where should the cameras be?

We first decided which were the best locations to set up our camera traps on. UVa grounds includes a lot of different environments with different potential fauna. Five cameras is enough for us to get pictures of various places, but not enough that we don’t have to be careful in positioning them.

Forest – When speaking of wildlife, the most obvious kind of area would be a woodland. There are a few wooded areas on grounds, the largest being Observatory Hill/Mount Jefferson around the McCormick Observatory, north/north-west of Hereford and in the Poplar Glen neighborhood. There are also small chunks of forest near Fontaine Research Park, in several places of North Grounds near the Law School and Lambeth Residential Area.

Near the water – We think it would be interesting to set up a camera or two close to the aquatic areas on grounds. There is the Pond, the Dell and the portion of Meadow Creek visible near the old dormitories or near Lambeth. Placing cameras here would maybe help us see animals that came to drink, birds, or aquatic fauna (like frogs).

The gardens – The various gardens near the Lawn and all around Central Grounds are definitely a good spot for us. They could give us insight on the nocturnal fauna of a densely built/inhabited area of grounds. Maybe we could find some bats here?

Urbanized places – near the hospital or in more urbanized places of grounds (near West Main Street, the gardens close to the Corner, etc.), we might try to see if there’s a kind of fauna that dwells near human activities. Maybe cats, mice, rats, and other semi-symbiotic species.

The dumpsters – everybody knows squirrels like to feast in the various dumpster across grounds, like near the IRC. Other animals might be sighted there at night, especially racoons or groundhogs.

UVa BioGrounds areas

Technical aspects

Finding good spots for the cameras is one thing, but it’s not everything. A lot of technical details must be taken into account. We contacted the expert researcher on Portland State University nocturnal fauna, Leslie Bliss-Ketchum, and she gave us some advice. The angle at which we place the cameras seems to be extremely important: it could determine whether we get a lot of pictures, or none at all. Leslie suggested that we lure animals, at least in the beginning, by placing oats and peanut butter on the ground near the cameras – so that we may see whether the angle we chose worked or not. We’ll also need to secure the cameras against potential theft and relocation, especially in public areas.

One of the aspects of the project will also be to set up a routine of checking-up the cameras, relocating them, storing the pictures, etc. We’ll work as a team to split up the work of placing and fetching the cameras, especially in relatively remote/inaccessible places.

Objectives and final project

What we hope to get is a lot of pictures of the most diverse species group possible. With enough data, we should be able to place a species’ habitat on a map of UVa grounds, as well as distinguish patterns regarding the time of the night when they come out, if urban activities disrupt them, etc.

Our findings should be presented on an interactive map, where it would be possible to see which species lives where, and to see what photos was taken at what spot. Hopefully this will help raise awareness about the diversity and richness of the nocturnal fauna in our University.


Image credits

Camera trap:

Map: from and edited by Gabriel Poulain


Post by Gabriel Poulain, Third-Year, Political Science