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