Author: Camilla Sherman

Being a Colorblind Birder

By Liam Wolff, Phinizy Research Intern

Can you picture the flaming orange throat of a Blackburnian Warbler? The vibrant rufous on a Hermit Thrush’s tail? The purple iridescence on a Lesser Scaup’s head? These are all sights a color deficient birder like myself will never be able to experience, or at least fully appreciate.

Colorblindness confuses many people. Often times when I tell someone about my colorblindness, their response is usually somewhere along the lines of, “so you can’t see any color at all?” Of course, like any decent troll, I tell them, “no, I see in black and white.”

But that’s a lie (or a bit of deadpan humor). Colorblindess, or more accurately, color deficiency, is not necessarily the total loss of color vision. There are many types of colorblindness, monochromacy (total color loss) included, that are caused by a faulty or absent cone cell in the retina. Since the cone cell in my eye that senses red light is malformed, I have Protanomaly and have a hard time distinguishing reds in other colors. For instance, what most people see as purple, I see as dark blue; pinks appear diffused and grayish; oranges are yellowish; and rufous is a light brown. Reds (e.g. scarlet) themselves are only less vibrant to me.

To illustrate what I see, I have added this comparison collage of a Hermit Thrush. Since I’m the colorblind one, please understand that the photo may not be 100% accurate.

Left: HETH with red tones decreased
Right: HETH with red tones untouched
I see no substantial difference between the two photos.

So how does colorblindess affect my birding? To be perfectly honest, it’s not much of a crutch. Regarding North American birds, the only genera I really have trouble with are Cathartes, Icterus, and Selasphorus. As I commented earlier, I have difficulty seeing rufous, which is one of the most reliable ways to differentiate Allen’s and Rufous Hummingbirds or Hermit and Gray-cheeked Thrushes. So how do I get around these problems? Other field marks and assistance from other birders. For example, Hermit and Gray-cheeked Thrushes can be distinguished by the density of the spotting on their chest and Rufous and Allen’s Hummingbirds can be differentiated by the shape of their tail feathers when extended. However, if I cannot see the chest of a Cathartes thrush, or if a Selasphorus hummingbird doesn’t extend its tail, I won’t be able to identify them as I should be. This is when I have to seek aid from my normal vision friends, who can help me identify the birds properly.

In the end, I do feel like I’m missing out on something, but it doesn’t affect my desire to find or identify birds. As amazing as birds would be in normal color, I don’t mind seeing them the way I do. Still, for those of you who are not color deficient, don’t take your ability for granted. Appreciate birds to the fullest!

Good birding!
Liam

Wetland Plant Series: Lichens

By Aaliyah Ross, Environmental Educator

This installment of the wetland plant series focuses on an organism that isn’t actually a plant. In fact, it isn’t even a single organism. Although they are often studied alongside nonvascular plants like mosses and liverworts, lichens are their own distinct and very unique group of organisms.

What is a Lichen?

Reindeer moss, a fruticose lichen, on the ground near the Beaver Dam Trail.

Lichens evolved as a symbiotic relationship between a fungus and another organism that produces food through photosynthesis (called a photobiont). The photobiont in a lichen can either be an algae, cyanobacteria (also known as blue green algae) or both. The photobiont provides a source of food while the fungus provides protection by enveloping the photobiont within its tissues, and provides moisture to the photobiont by transporting water directly into its cell walls. Therefore, a lichen can be considered an extreme example of symbiosis because the photobiont (either algae or bacteria or both) lives within the fungus’s tissues. It is a true composite organism.

Where do Lichens Live?

Foliose lichen on a cypress tree, Phinizy Center campus.

Lichens cover approximately 8% of the Earth’s surface. They live on trees, rocks, and soil, as well as on manmade objects like concrete and wooden surfaces. They are found everywhere from the poles to the tropics and from intertidal zones to mountaintops. They are abundant throughout Phinizy Swamp Nature Park as well. The next time you’re on a walk, take note of how many lichens you can see. Once you start paying attention to lichens, it can be hard not to notice them!

What do Lichens Look Like?

Brightly colored lichens cover the ground at Heggie’s Rock Preserve in Appling, GA.

The appearance of lichens is incredibly diverse; some are dull green, gray, slate blue, black or brown, while others feature bright red, orange, or yellow colors. Lichens can be grouped into three categories based on body form: Foliose lichens have leaf-like lobes, fruticose lichens are “shrubby” in appearance, and crustose lichens have a crust-like form that is often tightly embedded onto trees, rocks, or manmade surfaces.

What can Lichens Tell us about Air Quality?

Crustose lichen on a tree branch, Beaver Dam Trail.

Lichens are extremely sensitive to air pollution because they rapidly absorb compounds from the air and rainwater. If a pollutant even slightly damages one component of the lichen, the partnership will quickly break down and the lichen will die. The more of a lichen’s surface is exposed to the air, the more sensitive to air pollution it will be. Lichens are completely absent in the zone closest to a source of air pollution. Farther away, pollution tolerant crustose lichens begin to appear. Fruticose lichens are generally most sensitive to air pollution; a high abundance of fruticose lichens in area is an indicator of good air quality.

Wetland Plant Series: Common Duckweed

By Aaliyah Ross, Environmental Educator

Duckweed completely covers the water’s surface in one area of the swamp near the Boardwalk.

If you’ve been to the park this summer, you’ve likely noticed the bright green floating mats covering the water’s surface in many areas of the swamp. Is it pollen? Is it algae? No, it’s duckweed!

What is Duckweed?

Duckweeds are a subfamily (Lemnoideae) of floating freshwater plants that are among the smallest flowering plants in the world. There are many duckweed species; the common duckweed (Lemna minor) is found in slow-moving freshwater throughout North America and is abundant in Phinizy Swamp Nature Park. The plant consists of 1-3 leaves with a single root extending into the water. Like many wetland plants, it contains air spaces (called aerenchyma) between its tissues that hold oxygen, allowing it to stay afloat.

Duckweed aerenchyma: A microscopic image of duckweed leaves showing the aerenchyma (air spaces) between its tissues that allow it to stay afloat. Source: www.waynesword.palomar.edu

Although duckweed can produce tiny flowers, the plant primarily reproduces asexually. As leaves grow, the plants divide and become separate (but genetically identical) individuals. Duckweed is often spread to other bodies of water on the feet of waterfowl.

A Bane to Some, a Boon to Others

Duckweed can be a nuisance in garden ponds, fishing ponds, and other calm bodies of water used primarily for recreation. It thrives in water with high levels of nitrogen and phosphorus, which can come from animal waste, lawn fertilizer runoff, leaking septic systems, and decomposing plant material. Although it is native, it can behave like an invasive species, reproducing quickly and forming large, thick colonies. This can block sunlight from other aquatic plants and deplete the water of oxygen.

A small handful of duckweed contains dozens of individual plants.

Despite this, duckweed is extremely beneficial to many species. Its dense mats provide cover for small aquatic animals, including juvenile fish, insects and other macroinvertebrates. It also provides a nutritious food source for many waterfowl and fish. In fact, duckweed is cultivated for use in livestock and fish feed due to its high growth rate and protein content. It has also shown potential for use in biofuel production (Cui and Cheng, 2015).

A Natural Cleanser

Over 40 years of extensive research on duckweed has supported its potential for use in phytoremediation—the use of plants to remove pollutants from water or soil. Duckweed has been shown to remove nitrogen and phosphorus from swine wastewater (Chaipraprat et al., 2005), uranium and arsenic from mine drainage (Mkandawire et al., 2004; Mkandawire and Dudel, 2005), and even pharmaceuticals from wastewater (Brain et al., 2004, 2006)!

Pharmaceuticals (such as antibiotics, painkillers, birth control, and other hormone treatments) enter wastewater through the excretions of consumers, and also when expired medications are flushed down toilets. Most pharmaceuticals are not removed by current wastewater treatment methods, and as a result end up in streams. Some drugs can alter hormonal activity in aquatic organisms, causing detrimental effects such as sterility, developmental abnormalities, and death. Pharmaceuticals present a unique challenge for wastewater treatment because they persist in the environment and are active at extremely low concentrations. Additional treatment of wastewater with duckweed may prove to be an effective solution to this problem.

Wetland Plant Series: Spanish Moss

By Aaliyah Ross, Environmental Educator

Spanish moss on Bald Cypress trees, Floodplain Boardwalk

Long, wispy strands of gray-green moss draped over Live Oak branches is a familiar scene often associated with the Southeastern US. But although Spanish moss is one of the most recognizable plants at Phinizy Swamp Nature Park, its history and ecology are often misunderstood. Here are some interesting facts about this unique wetland species:

What’s in a Name?

The common name “Spanish moss” is a misnomer—the plant is neither Spanish nor a moss. Its native range extends from Argentina and Chile north through Virginia. Indigenous tribes called the plant itla-okla, i.e. “tree hair”. French explorers named the plant barbe espagnole, or “Spanish beard”, after the long beards worn by many Spanish conquistadores who were also in the Southeast at the time. The strange name stuck, and evolved over time into “Spanish moss”.

Trichomes on a strand of Spanish moss, which help the plant absorb and retain water. Source: Clemson University Extension, www.clemson.edu/extension/horticulture

Spanish moss is a bromeliad, the same family of plants that pineapples belong to. In fact, looking at a strand of Spanish moss under a magnifying glass reveals a pattern of overlapping scales (called trichomes) similar to that of a pineapple rind!

An Epiphyte, not a Parasite

Spanish moss is an epiphyte, which is a plant that grows on another plant for physical support. Contrary to popular belief, it does not remove water or nutrients from its host tree. Rather, the trichomes covering its strands are specialized to trap water from rain, fog, and water vapor in the air. This adaptation is why Spanish moss does not need roots. The relationship between Spanish moss and its host tree is best described as a commensalism; an ecological relationship in which one species benefits and the other is neither helped nor harmed.

Red Alert

Another common misconception is that Spanish moss contains chiggers, also known as red bugs. The biting larval forms of these tiny arachnids (adults don’t bite) often hang out in pine straw and tall grass, waiting for a passing host. They may also inhabit Spanish moss that has fallen to the ground, but Spanish moss on trees is unlikely to harbor chiggers.

Two Forms of Reproduction

Spanish moss produces small, inconspicuous flowers that are pollinated by wind.

On school field trips, one of the most common questions we get about Spanish moss is “How does it get in the tree in the first place?” Like many plants, it has two forms of reproduction. New Spanish moss plants are created when wind-dispersed seeds land in crevices in the bark of trees. It can also reproduce asexually when growing portions are broken off and carried by wind or birds to new trees, where they continue to grow.

On your next visit to the park, stop and take a minute to appreciate the incredible survival skills of this beautiful bromeliad!