Category: Phinizy Blog Feed

The Snag – Full of Life

The Snag – Full of Life
By: Ruth Mead

snag 2A snag – a tree that is dead but still standing as opposed to a log which is a dead tree lying on the ground – is still very much alive long after the tree itself has passed on. It’s hard to even imagine a forest or swamp without a snag, for the very ecology of the habitat relies on them. In fact, we do our neighborhoods injustice when we so quickly cut down our dead trees. At first, the decomposers come in, quickly eating away the cambium layer between the bark and the wood. These decomposers include many insects – especially beetle larva and termites, centipedes, lots of bacteria, and many more. Soon the bark falls off, leaving the tree naked. Woodpeckers come by looking for a good bug hidden under the bark. If they find a soft spot in the wood, they are able to excavate a nest hole. Cavities in the main stem are highly sought after by cavity nesters including bluebirds, chickadees, titmouse, and even larger birds like woodpeckers, wood ducks, and owls. Many cavity nesters use live trees, too, and some species of bats also roost in tree cavities. Some snags are short lived such as pine trees and tupelo. Others, such as cypress, can stand up to 75 years! Rat snakes love to investigate holes in snags, maybe looking for a cool spot on a hot day or more likely, their next meal. Besides bats, other mammals use cavities – such as snag 1raccoons and opossums. I was once with a group of students, and we stopped to look into a hollow spot in a tree. Much to our surprise, a group of baby opossums lay waiting for their mom. One of the girls screamed, but everyone agreed they were very cute.  Besides the inside of a snag, the outside might be more highly used. I can’t tell you how many birds use snags for perches, but mostly our birds of prey – waiting for the right moment to swoop down for their next dinner.

Featured Photographer: Liam Wolff

Featured Photographer: Liam Wolff

At Phinizy Center, we appreciate our fantastic photographers who allow us to use their photos of the park and its wildlife. This month, we are featuring photographer Liam Wolff. Liam’s photos have been featured in our 2015 calendar, park photo magnets and more. You can see more of his photos at our photo gallery or on his Flikr page.

Liam Wolff Great Egret (2)I’m a 19 year old freshman studying biology at Georgia Regents University. My interest in birds and wildlife started at 8 years old and, being homeschooled until graduation, I had plenty of spare time to develop my interest. At 13 I bought my first digital camera and since then photography has become a part of me. Although birds are my specialty, I enjoy trying my hand at HDR landscapes. I won first place plus an honorable mention at Phinizy’s 2013 photo contest.

Outdoors is where I feel most at home. There’s something about the moss-draped trees, the singing birds, the comforting wind that relaxes me like nothing else. It’s always wonderful to escape reality for a few hours and surround myself with nature. I often find myself travelling to distant Liam Wolff 38places in pursuit of this – to see wildlife that isn’t normally found in Augusta or to simply smell the salt of the sea. I have been to many incredible places and seen some amazing things. Yet Phinizy Swamp remains one my favorite places. It is an oasis for wildlife in Southeast Georgia. I know of no other park in the Coastal Plain that has such diverse habitat. The combination of wispy cypress swamps, whispering pine forests, and wistful marsh cells attracts a large variety of wildlife of all kinds – from birds and beavers to butterflies and bullfrogs. Many rare birds have graced the waters at Phinizy Swamp, some of which I have had the pleasure of observing myself, such as Surf Scoter, American White Pelican, and Ross’s Goose. The trails are safe and accessible and the animals may allow close views. It is well worth it any day to hike Phinizy Swamp. There is no better way to spend a morning, afternoon, or evening.​

Liam Wolff 55

EDS Science Night 2015

EDS Science Night 2015

20150210_183515Phinizy Center for Water Sciences’ education department once again participated in the annual Episcopal Day School Science Night. This fun filled night is a kickoff to their winter break and a venue for the middle school students to present their science projects. K through 5th graders also participate with a class display. The gymnasium comes to life with active displays of various science projects and demonstrations and students, teachers, parents, grandparents, and younger siblings scurry about taking in as many displays as possible.

photo 4Our educators are one of the few outside presenters every year. There is always a crowd around our tables as participants jump in for a chance to look at a macroinvertebrate (bug) under the microscope or catch the bugs out of the pans of water that we collected from Butler Creek. Some of the students seem to hang with us all evening as they feel compelled to find every bug in the water.

We began presenting at Science Night after having multiple field trips with the 6th and 7th graders for many years at the Swamp. With the help of EDS educators, we created off-site field trips to explore the water quality in both the canal (by kayak) and the river (by pontoon boat). photo 6These are now annual field trips for the 6th and 7th graders. Later this spring / summer, we will be providing the EDS teachers with curriculum training in both wetlands and GA Adopt-A-Stream.

We were happy to leave the event to a warm night as just one year ago we found ourselves in the middle of an ice storm as we stepped out of the gym.

Using Freshwater Invertebrates in River Monitoring

Using Freshwater Invertebrates in River Monitoring
By: Damon Mullis

0209150934In the summer of 2014, we implemented a quarterly macroinvertebrate sampling regime to complement our continuous water quality monitoring programs on the Savannah and Ogeechee Rivers. Macoinvertebrates are any of a wide variety of invertebrates that live in aquatic habitats and are large enough to be seen without the aid of a microscope. Examples include crayfish, snails, segmented worms, and insects. The tolerance level of these diverse, localized populations to environmental stressors varies widely. As a result, their community structures are reliable indicators of changing environmental conditions over time and space. This characteristic makes macroinvertebrate assemblages ideal indicators of aquatic ecosystem health and quality. In addition, macroinvertebrates play an important role in freshwater food webs, serving as prey for other organisms including fish, amphibians, and wading birds. However, their role in processes like breaking down organic matter and nutrient cycling is likely their most significant contribution to the ecosystem. In fact, we initiated these biomonitoring projects because of the ecological importance and environmental utility of macroinvertebrate communities.

We collect macroinvertebrates by deploying Hester-Dendy multiplate samplers tied to floats that suspend them approximately 2 feet below the water’s surface. These samplers do not trap invertebrates; rather, they supply a stable substrate for them to inhabit. Fungus and bacteria start to grow on the samplers soon after they enter the water. This growth encourages the 0209150931presence of species of macroinvertebrates that feed on these colonies. Other species use the stable substrate as a place to attach and filter food out of the flowing water. Predatory macroinvertebrates soon show up to feed on these other groups. After 30 days, the samplers are retrieved and the macroinvertebrates are identified, measured, counted, and classified into groups based on their ecological roles and tolerances to pollution. This data allows us to calculate abundance and biomass. We also use it to estimate diversity, biotic integrity, and functional roles for each community. Using this information in conjunction with data collected from our continuous monitoring stations allows us to detect changes in water quality and see how these changes directly impact biological communities.

 

Savannah River Dinosaurs

Shortnose Sturgeon

Shortnose Sturgeon

Atlantic Sturgeon

Atlantic Sturgeon

Savannah River Dinosaurs
By: Jason Moak & Kelsey Laymon

There are dinosaurs living in the Savannah River. While they may not be as fearsome as a Tyrannosaurus rex, they are every bit as primitive. These river dinosaurs are fish – the shortnose sturgeon (Acipenser brevirostrum) and Atlantic sturgeon (Acipenser oxyrinchus). Scientists have thought of sturgeon species as living fossils because their anatomy has not changed in over 100 million years. Sturgeons are long-lived, slow growing species that have been captured as a source of food and caviar which has contributed to their decline and landed them on the list of federally endangered species since 1967.

SCDNR Reasearcher with Shortnose Sturgeon

SCDNR Reasearcher with Shortnose Sturgeon

Sturgeon are unique among bony fishes because their skeleton is almost all cartilaginous. Unlike most fish, they are covered with bony plates called scutes instead of scales. They have an elongated body and barbels, similar to a catfish’s whiskers, which help them find their food, commonly aquatic insects, mollusks, and crustaceans.  Both of these species can live more than 60 years, and while shortnose sturgeon typically grow to about 3 feet long, some Atlantic sturgeon reach lengths of up to 14 feet!

Atlantic and shortnose sturgeons are found in rivers, estuaries and the sea all along the Eastern coast of North America. They are anadromous, a fisheries term meaning they spend most of their time in saltwater, but migrate up freshwater rivers from time to time for reproduction. In the Savannah River, the shortnose sturgeon spawns in the spring, but typically begin their upstream migration in January or February. Atlantic Sturgeon spawn from spring to fall, and can be found in the freshwater portion of the river throughout the year.

Phinizy Center Research Scientists Downloading Sturgeon Logger

Phinizy Center Research Scientists Downloading Sturgeon Logger

Phinizy Center scientists have worked with other researchers since 2009 to study the movements of these fish in the Savannah River. Currently, we help monitor a network of underwater sensors that detect when a tagged sturgeon swims past. The sensors record the date and time, as well as the unique ID of the tagged fish. Using this data, researchers are gaining a better understanding of which habitats are most important for these species and when they migrate to spawn.

The Dead of Winter – but Signs of Spring are Showing

The Dead of Winter – but Signs of Spring are Showing
By: Priscilla Hollingsworth

I was walking in the nature park a couple of days ago, on a chilly, depressingly gray day. At this time of year, grays and dull browns predominate in the landscape at the Phinizy Swamp:

winter view towards Butler Creek

view towards Butler Creek

But it turns out there is still plenty to see.  For one thing, if you look up at the tops of some of the trees, you can see the swelling of growth that will pop out into leaves in a few weeks:

Tree swelling for spring

Trees swelling for spring

The effect is still subtle, but the smallest branches of the trees just look thicker than a couple of weeks ago.

And I saw a couple of plants up close that are budding:

Buds

Buds

And this one, which I am pretty sure is one of those trees that I wrote about recently, the Bradford pear/Callery pear wild hybrids that are rampaging through our landscape:

"Frankenpear" - wild Bradford pear/Callery pear hybrid, with buds

“Frankenpear” – wild Bradford pear/Callery pear hybrid, with buds

This tree will be so pretty when the blooms come out, I will probably take another photo.

I saw some other interesting things on my walk.  Here’s a view of hairy poison ivy vines, in their winter state, but very much full of life and able to blister the skin of anyone who tries to pet their hairiness:

Hairy poison ivy vines on trees

Hairy poison ivy vines on trees

Here’s what looks like a mud ball, hanging from a dangling branch:

Mud ball

Mud ball

Could it be a mud dauber’s nest?  I wasn’t able to identify it.

Note on 2/10: Aaliyah Ross, Environmental Educator at the Phinizy Center, advises that this strange-looking ball is probably a gall.  Thanks, Aaliyah!  I looked up galls, and they are growths on trees that can be caused by a variety of organisms foreign to the host tree, such as insects, fungi, bacteria, nematodes, and even other plants!  Sometimes the gall is harmful to the host plant, and sometimes not.

Winter is a great time for being able to see into the woods.  You can see structures that later will be covered over with green growth:

Small tree trunk twisted by a vine

Small tree trunk twisted by a vine

The vine that caused the young tree to swell and twist is still embedded in the trunk.

And finally, here is some really interesting-looking swamp water, as viewed right off the School Bus bridge:

Red patch and slime in the water

Red patch and slime in the water

I wish I could identify what is happening here.  My own research didn’t yield any real information.  At the lower left in the photo above, you can see a red growth or substance.  And in the middle, the water has interestingly thick and slimy-looking areas.

Note on 2/10:  Aaliyah Ross advises that the red substance is mosquito fern.  Mosquito fern, genus Azolla, is a tiny plant that grows rapidly on the surface of water that is not moving fast.  It can be red or green, at different times of the year, responding to temperature and sunlight changes.   Mosquito fern has some interesting qualities and can be a beneficial part of an ecosystem – or when there is too much fertilizer runoff into a wetland, it can grow too much and become invasive.  As for the slime in the water on the right, Aaliyah says this is the result of some kind of bacterial action, in which bacteria are decomposing plant matter.   Personally, I think slime is fascinating, and I look forward to learning more about it.

Even a dull winter day at the swamp yields some interesting sights.

-Priscilla Hollingsworth

Distinctively Colored Mayfly Nymphs

Distinctively Colored Mayfly Nymphs Collected From the Ogeechee River
By: Damon Mullis
Tricorythode nymph

Mayfly

Recently while processing invertebrate samples from the Ogeechee River, I spotted six exceptionally colored mayfly nymphs. They were very small (2-4mm in length) and had striking pink markings. Upon further inspection, I discovered that they were a species of mayfly within the Tricorythode genus. There are thirteen species of Tricorythodes in North America, with four species regularly occurring in our area. While insect biologists have discovered characteristics to distinguish between these species in their adult life stage, no one has done the tedious work of rearing them in a laboratory to reveal differences in the nymphs. As a result, we are unfortunately only able to identify these nymphs to the genus level.

Tricorythode nymphs are typically found in areas of flowing water in large streams and rivers. They prefer slow moving water that is slightly acidic, making the rivers and streams of the Coastal Plain of Georgia an ideal environment. They feed on the dead plant material and diatoms that are plentiful in this habitat. These rivers and streams are also pretty silty, so these little insects have evolved specially adapted gills. The first pair of gills are thickened and plate-like and do not function to obtain oxygen. They cover the functional gills and protect them from being covered with silt, which would prevent them from obtaining oxygen. To obtain dissolved oxygen, they raise the plate-like gills slightly and circulate water under them by waving the functional gills back and forth.

Too smart for our own good: the Callery Pear and the Bradford Pear

I have been looking at these amazingly thorny young trees that are growing on some of the berms (levees/roadways) that run between the ponds of the constructed wetlands. What amazing texture – and what horrible thorns. It would be hard to imagine pushing my way through a thicket of these.

Callery pear hybrid web

Frankenstein meets the Bradford pear tree

Ruth Mead (Senior Environmental Educator at the Phinizy Center) pointed out to me that these thorny trees are related to Bradford pear trees. You know Bradford pear trees – they are everywhere, in parking lots and suburban yards. For a long time, these were considered perfect landscaping trees: they grow fast, they are oblivious to poor growing conditions, and they are pretty most of the year (flowers in the spring, glossy green leaves in summer, dramatic leaf colors in the fall). Later on, people started recognizing that mature Bradford pear trees crack and break limbs easily because of the growth pattern of their branch structure. But other than that, this seemed like an ideal, easy tree to grow in yards and on city streets. Many people still love and grow them.

It turns out that the truth is much more complex than that. Remember the promise of kudzu? It was supposed to be this great, fast-growing plant that controls erosion on steep hillsides in the South. It was imported from Asia. We all know that kudzu turned out to be a disaster, the green monster that Eats The South. In other words, kudzu is a poster child for the concept of an invasive species. How did a good thing become a bad thing? Sometimes human decisions go wrong.

Callery pear closer web

“Franken-Bradford” closer up

Bradford pear trees were developed in the U.S. as a variant of Pyrus Calleryana, or Callery pear trees. Seeds from Callery pear trees were brought from China beginning around 1918 as part of a possible solution to a pear tree disease that was devastating American pear fruit crops. The Callery pear tree is highly resistant to various diseases, and it grows well in a variety of environmental conditions. Over decades of experimentation and research, botanical scientists in the U.S. developed cultivars of this plant with promising qualities. The most famous cultivar was the one named Bradford. And for decades, Bradford pear trees were planted seemingly everywhere, with few problems. A useful feature of the Bradford pear was that it seemed to be NOT invasive – it was basically sterile. Bradford pear trees produce lots of pretty flowers, but usually no fruit or seeds. What’s not to love about that? If you need another tree, you can buy them at all the major garden centers, because horticultural businesses can make more trees through grafting and other methods.

However, scientists did not stop experimenting with the Callery pear tree when they discovered the Bradford cultivar in the 1960s. In the decades since then, more variants have been brought onto the market – pear trees with various desirable qualities that are a little different from the Bradford. Within the last ten years, there has been a sudden explosion of spontaneously appearing trees like the one in my photo. Many of these unwanted Callery pear trees grow extremely rapidly and have very tightly arranged branches studded with long thorns. They appear in thick stands at the edges of cleared land, along fence lines, and along roadways. Cutting the trees down makes them grow even faster and thicker from the roots. They are resistant to diseases, too painful for deer to munch on because of the thorns, and they crowd out the plants that would naturally grow in these spots. Yow! I think I could write a horror movie script about these trees. How did this situation come to pass?

Callery pear closest web

Scary!

It turns out that, for specific genetic reasons, Callery pear varieties are often sterile in terms of being able to pollinate themselves or other trees of the same variety. So, a tree that is sterile isn’t going to become invasive, right? But as more varieties came on the market, the different varieties were sterile in relation to their own kind – but often fertile when pollinated by a slightly different variety. And the different varieties back-crossed with each other, often bringing out extremely undesirable qualities (such as lots of thorns) in trees that then grow freely in locations that are not mowed regularly. Another kudzu-monster has been born. And did you know that the southern U.S. is on the same latitude as the part of China where the original Callery pear tree is native and grows most easily? American Callery pear hybrids will be that much harder to eradicate in our region because of this.

So was there ever a point when reasonable scientists, administrators, government officials, etc. could have reasonably suspected that their efforts to improve American pear trees might take a dark turn? And what do we do now about our invasion of self-hybridizing Asian pear tree descendants?

For further history of the science involved with Callery pear research, this is a good article:
http://bioscience.oxfordjournals.org/content/57/11/956.full

-Priscilla Hollingsworth

Raccoon spotted!

While walking in the swamp recently, a raccoon ran across my path. It quickly climbed high into a tree, and stayed there, looking down at me.

I’m familiar with raccoons in my backyard, raccoons in alleys, raccoons getting into the trash.  But I wondered, what’s it like to be a a wild raccoon living at the Phinizy Swamp?

raccoon in tree

raccoon in tree

The most interesting thing about raccoons to me is how adaptable they are. They are quite smart and are good at learning how to work new situations to their advantage. Their Latin name is Procyon lotor, which more or less means “doglike animal that washes a lot” (they are actually a little more closely related to bears than dogs). They are native to forests and waterways all over North America, though they may well have originated in the Southeast. So you could say that this raccoon that I saw is in its most native habitat – in a forest/wetlands area in Georgia.

raccoon closeup

raccoon closeup

Raccoons are omnivores, and they do their best to get a varied diet. In the swamp, they are probably eating plant parts such as nuts and fruits, eggs from birds’ nests, worms and crustaceans and other invertebrates from soil and water areas, smaller vertebrates, and even carrion. In other words, they sample widely from everything available to them in a forest/wetland habitat.

The “washing” behavior isn’t fully understood. It may be somewhat instinctive and derived from the raccoon’s origins as a hunter along waterways. The raccoon’s skin on its forepaws is extremely sensitive, and seems to become more so when it is moistened.

A raccoon’s rear paws are also special. Unlike a cat’s, a raccoon’s back paws can rotate backwards as the animal descends a tree – so the raccoon that I saw could as easily run down the tree trunk as it ran up. Wild raccoons tend to sleep and nest in trees.

In really cold winter weather, raccoons can go into a state called “winter rest”. It’s not hibernation – their heart rate drops, but their body temperature stays normal. If the weather warms up, a raccoon can quickly come out of winter rest and get moving again.

A raccoon in the wild lives for two to three years, usually. In captivity, raccoons live a more catlike lifespan. Most wild raccoons are killed by disease or by getting run over by an automobile when they cross a road. The natural predators for the raccoon I saw would be bobcats, coyotes, and the larger birds of prey.

Finally, raccoons are most active at night, but it isn’t that unusual to see them during the day. They are just so adaptable in their behaviors that almost any rule you could cite about them has exceptions.

-Priscilla Hollingsworth

The Tiniest Catfish

IMG_4442Most folks in these parts have had the pleasure of consuming catfish at some point in their lives. You might know that some catfish species found in our area can grow quite large – the Georgia state record blue catfish caught in 2010 weighed 80 lbs! What you might not know is that there are some catfish in our local creeks and rivers that don’t get much bigger than your pointer finger.

Recently, while checking on a water quality monitor in the Savannah River, one of our researchers found one of these small catfish, called “madtoms,” hiding in the small cage that guards the probes. This particular species is a speckled madtom (Noturus leptacanthus), named for the numerous spots covering its body. This species grows to a normal length of about two inches and typically lives two to three years.

IMG_4441The speckled madtom are found in both small creeks (they are present in Butler Creek at Phinizy Swamp Nature Park) and large rivers. They typically spend most of their day hiding in crevices around rocks or fallen trees and limbs and come out at night to feed on prey, which is mostly made up of small aquatic insect larvae. To protect themselves from predators, madtoms have bony, sharp spines that actually contain venom. This biologist can confirm that being stuck by a madtom spine is fairly painful, so be careful if you ever encounter one of these tiny catfish!