Life in the Saltmarsh - Part 1

 

Sunrise over the saltmarsh at low tide.
Huntington Beach State Park, South Carolina.

Sometimes our travels take us to saltmarshes along the southeast Atlantic coast.  One of our favorite locations is Huntington Beach State Park in South Carolina.  The park has extensive saltmarshes with numerous access points that allow easy exploration of this unique ecosystem.   

Smooth Cordgrass, Spartina alterniflora at high tide.
Huntington Beach State Park, South Carolina. 

Saltmarshes appear simple, just one species of plant for acres and miles.  But look a little closer and all manner of life can be found.  The plant that predominates southeastern saltmarshes is Spartina alterniflora or Smooth Cordgrass.  

This remarkable grass not only lives but thrives in a very harsh environment.  Twice a day the tide rolls in.  As seawater partially submerges the Spartina plants they experience dramatic changes in salinity and temperature.  These environmental fluctuations prevent other plants from growing in the marsh, so Spartina provides the basis for the saltmarsh food chain.  

Marsh Periwinkle (Littoraria irroata) on Spartina.
Huntington Beach State Park, South Carolina. 

One of the most abundant animals in the saltmarsh is the Marsh Periwinkle (Littoraria irrorata). This small snail grazes on algae in the marsh mud and on dead Spartina. Amazingly, these lowly creatures also practice a primitive form of agriculture.  Marsh Periwinkles make wounds on living Spartina stems that become infected with a fungus.  Snails that eat the fungus grow more rapidly and have a better survival rate than those without access to the fungus.  

Marsh Periwinkle on mud at low tide. 
Huntington Beach State Park, South Carolina. 

Marsh Periwinkles are preyed upon by many animals including the reclusive Clapper Rail (Rallus crepitans).  These shy, chicken-like birds are more often heard than seen.  Clapper Rails walk the marsh mud and between the stalks of Spartina where they catch not only Marsh Periwinkles but also crustaceans, small fish and insects. Clapper Rails are dark brown with fine barring on the sides, a turned up white tail and a strong beak.  When viewed from the rear, Clapper Rails look like they have been squeezed.  They are as thin as a rail.  This compressed body shape allows the Rails to slip between the Spartina stems and quickly disappear.   

Clapper Rail (Rallus crepitans) dashing across the mud at low tide.
Huntington Beach State Park, South Carolina. 

Clapper Rail about to disappear into the Spartina.
Huntington Beach State Park, South Carolina.  

Fish are abundant in the tidal creeks of the saltmarsh and are fed upon by many wading birds.  Great Blue Herons (Ardea herodias), Great Egrets (Ardea alba) and Snowy Egrets (Egretta thula) impale fish with their long, pointed beaks. White Ibises (Eudocimus albus) and Wood Storks (Mycteria americana) work their open bills through the shallow water and snap up any prey they encounter.

Great Egret (Ardea alba) and 
Great Blue Heron (Ardea herodias) fishing at low tide.
Huntington Beach State Park, South Carolina. 

Snowy Egret (Egretta thula).
Huntington Beach State Park, South Carolina. 

Snowy Egret with a fish.
Huntington Beach State Park, South Carolina. 

White Ibis (Eudocimus albus).
Huntington Beach State Park, South Carolina. 

Wood Stork (Mycteria americana).
Huntington Beach State Park, South Carolina. 

Wood Stork feeding.
Huntington Beach State Park, South Carolina. 

Double-crested Cormorants (Phalacrocorax auritus) dive in the tidal creeks and catch fish with their hooked beaks. These relatives of pelicans are found in large numbers along the coast, on inland lakes and rivers.

Double-crested Cormorant (Phalacrocorax auritus).
Huntington Beach State Park, South Carolina. 

Double-crested Cormorant with a fish.
Huntington Beach State Park, South Carolina. 

Ospreys (Pandion haliaetus) are large birds of prey and have a most dramatic fishing style.  They dive from heights, plunge into the water feet first and snatch swimming fish.  Ospreys then lift off from the water carrying their catch in their sharp talons. 

Osprey (Pandion haliaetus).
Huntington Beach State Park, South Carolina. 

Roseate Spoonbills (Platalea ajaja) have a unique feeding style.  These pink waders sweep their spatulate bills through the mud catching fish and invertebrates they encounter.     

Roseate Spoonbill (Platalea ajaja).
Huntington Beach State Park, South Carolina. 

Roseate Spoonbill feeding.
Huntington Beach State Park, South Carolina. 

Saltmarshes are remarkable places.  Despite their apparent simplicity they are quite diverse and are a key to the coastal ecosystems. Saltmarshes teem with life and serve as a bulwark against hurricanes. So much is going on here, this blog will continue exploring saltmarshes in the next installment. 

Saltmarsh.
Huntington Beach State Park, South Carolina. 

A Fall of Flamingos

 

Greater Flamingo (Phoenicopterus roseus).
Etang de Grussian, France

This fall, circumstances placed flamingos in our path.  Diane and I don’t usually see flamingos but between a hurricane and a long-planned trip to Europe we got to see two different species of these special birds. 

Tropical storm Idalia formed in the Western Caribbean in late August 2023.  It wandered about the northern tip of the of the Yucatan Peninsula of Mexico then entered the Gulf of Mexico.  The warm Gulf waters fueled Idalia’s intensification into a major hurricane.  Idalia came ashore in the Florida panhandle as a category 3 hurricane.  The storm crossed northern Florida where it weakened to tropical storm strength. It crossed southern Georgia and entered the Atlantic off South Carolina.  Idalia then swept past the coast of North Carolina and out into the North Atlantic. 

The track of Tropical Storm/Hurricane Idalia.
August-September 2023.
https://www.nhc.noaa.gov/archive/2023/IDALIA_graphics.php?product=5day_cone_with_line

Hurricanes are notorious not only for mass destruction and loss of life but also for bringing unusual birds to North America.  Many storms deposit sea birds far inland where they can be seen flying over large lakes.  Idalia did something more. 

There are large breeding colonies of American Flamingos (Phoenicopterus ruber) at the northern end of the Yucatan Peninsula.  These tall, long-legged wading birds have black wings, pink feathers and a large, curved beak.  They breed in the spring and the young birds join in large groups called creches. Young Flamingos are easy to tell from adults because they are gray rather than pink.  Flamingos eat crustaceans and other small creatures by filtering them through sieve-like structures in the beak.  The crustaceans that make up their diet contain red carotenoid pigments that are deposited in new feathers as they grow.  So, American Flamingos turn pink in their second year after consuming pigment containing food.  This species is normally found on islands of the West Indies, coastal areas of Mexico bordering the Gulf and the Caribbean, north coasts of Colombia and Venezuela, and the Galapagos Islands.   

Hurricane Idalia picked up some of the Yucatan American Flamingos and deposited then across the United States. Many ended up in Florida and around the Gulf Coast to Louisiana.  Other Flamingos found themselves far inland.  The storm-blown flamingos were recorded in Kansas, Missouri, Maryland, Virginia, Tennessee, Kentucky, South Carolina and North Carolina. 

American Flamingos (Phoenicopterus ruber).
Pea Island National Wildlife Refuge, North Carolina.
Photo courtesy of Karen Lebing. 

Hurricane Idalia brushed past the North Carolina coast on August 31 and on September 2 birders began reporting 11 American Flamingos at the Pea Island National Wildlife Refuge on the Outer Banks. Three of the birds were pink adults and 8 were gray immatures.  The flamingos persisted in the area and numbers increased to 17, with 4 adults and 13 immatures.  Diane and I did not get to see these unusual birds until September 18.  On that day the flamingos were out in Pamlico Sound, and we had to climb a dune to get distant views with a spotting scope.  This was the first time American Flamingos were recorded in North Carolina.

American Flamingos flying over Pamlico Sound.
Pea Island National Wildlife Refuge, North Carolina.

What will become of these vagrants American Flamingos?  Some could return to Mexico, others might be lost to predation, but some may stay.  An American Flamingo was blown to the St. Marks National Wildlife Refuge in north Florida by Hurricane Michael in 2018.  It has been living there ever since.  Some of the storm-tossed birds may take up residence and even breed.  There is a village named Flamingo at the south end of Everglades National Park in Florida.  American Flamingos were abundant in south Florida in the late 19^th century, perhaps they will be again, thanks to Hurricane Adalia.   

We traveled to the south of France in early October 2023 to visit friends and to see birds.  One of our targets was the Greater Flamingo (Phoenicopterus roseus). The Greater Flamingo lives in India, the Middle East, Africa and much of Mediterranean coast of Europe.  It is the largest of the world’s six flamingo species with some standing 6 feet in height.  Adult Greater Flamingos are pale pink in color with red and black on the wings that can be seen when the birds fly. Like in the American Flamingo, the first-year birds are gray and develop their color as the molt in new feathers in their second year. 

Greater Flamingos (Phoenicopterus roseus)with
the ruins of Chateau Grussian in the background.
Etang Grussian, France. 

Diane, two friends and I found a flock of dozens of Greater Flamingos in a brackish lagoon called Etang de Grussian near the Mediterranean coast of France.  The ruins of Chateau Grussian frown down on the lagoon where the flamingos fed, rested and flew about.  Other ponds in the area gave us views of hundreds more of these stunning birds.  

Greater Flamingos landing.
Etang Grussian, France. 

We rarely see wild flamingos, so for us to see two species, on two continents, in one season was a rare treat indeed.  

Greater Flamingos feeding.
Port Grussian, France.

Thanks to Karen Lebing for allowing the use of her excellent photo of American Flamingos. 

Tent Caterpillars and Webworms

 

Eastern Tent Caterpillars (Malacosoma americanum)
and web on Black Cherry (Prunus serotina). 
Rowan County, North Carolina.

There are about 12,000 species of moths in North America, and each one comes from caterpillars.  In some species this larval stage is tiny and inconspicuous, others are large and impressive.  While all caterpillars can make silk, a select group weaves a large web to house and protect the larvae.   

Two caterpillars in our area make impressive webs on trees, the Eastern Tent Caterpillar (Malacosoma americanum) and the Fall Webworm (Hyphantria cunea).

A large group of Eastern Tent Caterpillars swarming on
their web.  This tent was made in an ornamental cherry tree (Prunus sp.).
Rowan County, North Carolina. 

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Eastern Tent Caterpillars hatch in spring and build large, tent-like webs at the forks of tree branches. The caterpillars are usually found on trees in the Rose family, the Rosaceae.  We see their webs most often on Wild Cherry (Prunus serotina).  Each web may host several hundred caterpillars.  Eastern Tent Caterpillars go through 6 larval stages called instars. Each instar is larger than the last and the caterpillar molts between these stages.

A sixth instar Eastern Tent Caterpillar feeding on
Black Cherry leaves.
Rowan County, North Carolina. 

The Eastern Tent Caterpillars shelter in the web and crawl out the tree branch to feed on leaves.  The caterpillars eat several times a day and then return to the web. The web controls the temperature and humidity to give the best environment for caterpillar development.   The final instar is about two inches long, dark brown with a white stripe down the middle of the back and blue, black and yellow markings on the side.  Caterpillars of all stages have hairs called setae that help in thermoregulation and may deter predators. Birds are the main predators of Eastern Tent Caterpillars.  The birds prefer the early instars, probably because of the large, irritating setae of later stages.  The final larval stage may wander from the host tree and pupate in a sheltered location.  The moth stage of the Eastern Tent Caterpillar emerges in early spring, lays eggs on a tree and the cycle begins again. 

A sixth instar Tent Caterpillar wandering from the web.  
This one was on a metal fence post. 
Rowan County, North Carolina. 

As their name suggests, Fall Webworms appear in late summer and are present through the fall.  The Fall Webworm Moth lays eggs on the host tree in summer and when the caterpillars hatch, they immediately begin spinning their webs. The webs enclose whole tree branches, including leaves.  The caterpillars eat the soft tissue of the leaves, leaving behind the veins.  Fall Webworms remain within their web to feed and as leaves are consumed, they expand the web to include fresh leaves. Fall Webworms go through 5 larval instars in their development with the final instar being about 1½ inches long, yellow in color with long white setae. 

Fall Webworms (Hyphantria cunea) in their web. 
The host tree of this web was
an Eastern Redbud (Cercis canadensis).
Rowan County, North Carolina. 

Detail of Fall Webworms and web.
Rowan County, North Carolina.

A fifth instar Fall Webworm surrounded by
 earlier larval stages. 
Rowan County, North Carolina. 

Fall Webworms use dozens of deciduous tree species as their host. This fall in our yard they took over branches of Eastern Redbud (Cercis canadensis) and Red Mulberry (Morus rubra).  Birds are major predators of Fall Webworms. Yellow-billed Cuckoos (Coccyzus americanus) on fall migration will tear open the webs and eat dozens of the caterpillars. Fall Webworms are native to North America but have been introduced to Europe and Asia where they are considered invasive species. 

A Yellow-billed Cuckoo (Coccyzus amerianus)
eating fall Webworms.
Orange County, North Carolina. 

 

A fifth instar Fall Webworm outside the web on
Red Mulberry (Morus rubra).
Rowan County, North Carolina. 

While Eastern Tent Caterpillars and the Fall Webworms are superficially similar, they are easy to tell apart.  Eastern Tent Caterpillars appear in early spring and make their webs at the fork of tree branches.  Fall Webworms show up later in the year with webs that enclose branches including leaves.  Both these caterpillars do some damage to trees but do not kill them.  I think these two caterpillars are bookends of the growing seasons of the year.  Eastern Tent Caterpillars to open the spring and Fall Webworms to close out the warm months.  

Video of Eastern Tent Caterpillars 

and Fall Webworms.

Rowan County, North Carolina 

Kudzu and its Bug: A Tale of Two Invasives

 

Kudzu (Pueraria montana)
growing over trees.
Rowan County, North Carolina. 

Kudzu (Pueraria montana) is a famous, nay infamous, invasive vine from Asia.  It was introduced to the United States, like many invasive species, with good intentions.  It was imported as an ornamental plant in the late 19^th century and was used by United States Soil Conservation Service in the early 20^th century to control erosion in the south.  Kudzu is known as "the vine that ate the south" and grows over fields, trees, power poles and buildings. 

A trifoliate compound leaf of Kudzu.
Rowan County, North Carolina. 

Early spring Kudzu vine.
Rowan County, North Carolina. 

Twining vines of Kudzu.
Rowan County, North Carolina. 

Kudzu growing over a house.
Rowan County, North Carolina. 

Kudzu is a member of the Fabaceae, the pea family.  It has large, trifoliate compound leaves and hairy stems. Like many members of this family, Kudzu roots harbor nitrogen fixing bacteria that allows the vine to thrive in even the poorest soils. Kudzu has large tap roots resembling sweet potatoes that are rich in starch. In late summer, Kudzu produces inflorescences of beautiful purple and yellow flowers that smell of grape jelly.   In fall, Kudzu makes a hairy pod containing bean-like seeds.

A Kudzu inflorescence.
The inflorescence blooms from the bottom up.
Rowan County, North Carolina. 

A closeup of a Kudzu flowers.
Rowan County, North Carolina. 

Kudzu fruits.
Rowan County, North Carolina. 

While the plants do make seeds, Kudzu usually spreads by vegetative growth.  Stems that make contact with the soil make new roots and with a growth rate of a foot per day, the vines can ramble long distances in a single growing season.  Kudzu can kill other vegetation including large trees when the leaves and vines block out light and the roots outcompete other plants. 

Kudzu smothering trees.
Rowan County, North Carolina.

Control of Kudzu has proven difficult, and many methods have been tried.  Mowing a stand of Kudzu for several seasons or grazing with goats can remove the invasive plants.  Digging up the vines and herbicide application also works to get rid of Kudzu.  The aerial portions of Kudzu are killed by the first hard freeze and that makes a landscape of brown leaves and vines.  During the winter there is some decay of the dead vines but the following spring the plant begin its relentless growth again. 

A stand of Kudzu in winter.
Rowan County, North Carolina. 

In 2009 a new insect, Megacopta cribraia, started appearing in the counties around Atlanta, Georgia. This invasive insect is called the Kudzu Bug does feed on Kudzu, but it also causes severe damage to Soybean (Glycine max) crops.  Kudzu Bugs are true bugs in the Order Hemiptera and are native to East Asia, the same area that gave us Kudzu.  Kudzu Bugs are small, about ¼ inch long, dark brown and emit a foul, stinkbug-like odor when disturbed. Besides living on Kudzu and eating Soybean plants, this bug is also a pest around homes.  Kudzu bugs are attracted to white or yellow buildings and can congregate in large numbers on houses.  This new invasive insects probably arrived from Asia as stowaways on an airliner.  Since their arrival in 2009 Kudzu Bugs have spread out from Georgia and are now found from Texas to New Jersey and are a major concern for Soybean farmers.  

A Kudzu Bug (Megacopta cribraria) on a Kudzu leaf.
Rowan County, North Carolina. 

A group of Kudzu Bugs on a Kudzu leaf.
Rowan County, North Carolina. 

When Kudzu arrived in North America it found a favorable habitat with few natural enemies, and so it spread. Kudzu now grows from Florida to the Midwest and into Mid-Atlantic states. Contrary to some rumors, Kudzu Bugs were not intentionally introduced to control Kudzu.  Although the bugs do reduce the growth of the vine, it is unlikely this second invasive species will stop the march of  the "vine that ate the south".  

A Kudzu landscape.
Rowan County, North Carolina. 

Some Florida Notes

 

Juvenile Pied-billed Grebe (Podilymbus podiceps).
Green Cay Wetlands, Palm Beach County, Florida. 

Diane and I visited south Florida in August. It was hot.  The low temperatures at night were in the 80s and it went up from there.  These were not the best conditions for nature observation.  Birds were quiet and mammals were hiding out, but we went out each day to visit wetlands.  Even in these steamy conditions we saw some interesting sights. 

Adult Pied-billed Grebe feeding young.
Green Cay Wetlands, Palm Beach County, Florida. 

Many of the birds were still taking care of their last brood of the year.  An adult Pied-billed Grebe (Podilymbus podiceps) was teaching its two babies to catch fish.  The adult would dive, bring up a fish and drop it and let the juveniles try their hand at fishing.  This went on for at least 20 minutes and the fish was getting a little worse for wear by the time we left.  The young Pied-billed Grebes had a striking color pattern with gold, black and white stripes on their heads and pink at the base of their pied bills.  

Common Gallinule (Gallinula galeata).
Green Cay Wetlands, Palm Beach County, Florida. 

 

Adult and juvenile Common Gallinules.
Wakodahatchee Wetlands, Palm Beach County, Florida.

Common Gallinules (Gallinula galeata) and were also busy raising their young.  A baby Common Gallinule still had some downy black feathers and a partially bare head.  Its beak was yellow with a black mark and just a hint of red at the base.  The parent by contrast was dark gray with a yellow-tipped red beak.  Above the beak adult Common Gallinules had a red shield.  This structure is found in certain members of the Rail family, the Ralllidae, and probably functions in attracting mates.  Another striking feature of adult Common Gallinules was their legs and feet.  The toes are long allowing the birds to easily walk across floating vegetation.  The legs and toes are bright yellow with a red band near the body.    

An Black-bellied Whistling Duck (Dendrocygna autumnalis)
admiring the sunrise.
Green Cay Wetlands, Palm Beach County, Florida. 

Back-bellied Whistling Ducks (Dendrocygna autumnalis) were leading their latest offspring.   An adult was waddling through the shallows being trailed by a line of rather large ducklings. These handsome ducks have a gray head, brown body, a pink beak and, of course, a black belly.  The young ducks look much like adults but with a gray beak.  Black-bellied Whistling Ducks were formerly found in the American tropics but have expanded their range through the southern and eastern United States and north into Canada. 

Adult and juvenile Black-bellied Whistling Ducks.
Wakodahatchee Wetlands, Palm Beach County, Florida. 

Least Bitterns (Ixobrychus exilis) are the smallest of our herons.  They have short necks and short legs and spend their time hiding among the reeds.  It is rare to get a good look at one of these shy waders so the day we saw three was a real treat.   A family group was working their way across a marsh jumping between the rushes (Juncus sp.) then flying across short gaps of water to disappear again in the vegetation.

 

Least Bittern (Ixobrychus exilis).
Green Cay Wetlands, Palm Beach County, Florida. 

Dragonflies were active in the summer heat.  These voracious predators flew across the marsh searching for insects and would briefly perch on the tips of plants. Brilliant Blue Dashers (Pachydiplax longipennis) were common with their bright blue bodies and emerald eyes.  

A male Blue Dasher (Pachydiplax longipennis). 
Green Cay Wetlands, Palm Beach County, Florida. 

Four-spotted Pennants (Brachymesia gravida) were abundant in the marsh. Their common name comes from the dark spot on each of the dragonfly's four wings.  They also have a small white spots called stigma on the leading edge near the tip of the wings.  

Four-spotted Pennant (Brachymesia gravida).  This is
a female with light brown wing spots. 
Green Cay Wetlands, Palm Beach County, Florida. 

The most dramatic dragonflies we saw were the Halloween Pennants (Celithemis eponina).  The males are orange with brown wing spots.  This color pattern is reminiscent of Halloween decorations and gives the insect its name. Females are a little less orange but still have the dark wing spots.  Halloween Pennants have the curious habit of perching with their front and back wings held at different angles. 

Halloween Pennant (Celithemis eponina). 
Green Cay Wetlands, Palm Beach County, Florida. 

Halloween Pennant.
Green Cay Wetlands, Palm Beach County, Florida. 

On a boardwalk that crossed a pond, we saw feathers floating on the water.  The first feather was a primary, white with a black tip. It was from a White Ibis (Eudocimus albus).  I thought it had been dropped by a molting bird since they replace their feathers after the breeding season.  Then other feathers started drifting by.  There were more primaries, then secondaries, then body feathers.  This peaceful sight of floating feathers started to look like something darker.  Like leftovers from an alligator's meal. 

White Ibis (Eudocimus albus).
Wakodahatchee Wetlands, Palm Beach County, Florida. 

White Ibis primary feather floating.
Green Cay Wetlands, Palm Beach County, Florida.

White Ibis body feather floating.
Green Cay Wetlands, Palm Beach County, Florida. 

It was fun going out on those slow, hot Florida days.  Several people told us, “Come back in October, when the weather is nicer.”  We will.