Pleistocene Storks of North America

At least 4 species of storks lived in North America during the Pleistocene.  The wood stork (Mycteria americana), the only surviving species, is nearly absent from the fossil record.  It is known from just 1 fossil site–a tar seep in Cuba.  This fossil specimen was found associated with fossils from 2 other species of stork including Wetmore’s (M. wetmori), a similar species but distinctly larger.  Fossil evidence of Wetmore’s stork has also been excavated from sites in Florida and California, indicating it was a widespread species.  Prior to the discovery that wood storks co-existed with Wetmore’s storks on Cuba, scientists assumed the former didn’t colonize North America until the extinction of the latter at the end of the Pleistocene.  But this discovery casts doubt on that assumption.  Wood storks may have lived in parts of North America where the process of fossilization was uncommon.  There is evidence that 2 species of large owls lived in Georgia during the Pleistocene, but the fossil material is so scant scientists are unable to as yet describe the species.  This demonstrates how incomplete the fossil record can be.

The other species of stork that lived in Cuba then was an unknown and undescribed species in the Ciconia genus.  There are 7 extant species of storks in the Ciconia genus including the well known white stork (Ciconia ciconia), a bird that winters in Africa, summers in Europe, and according to legend, brings babies to awaiting parents.  The maguari stork (C. maguari) ranges throughout South America where flooded grasslands predominate. It’s the only extant American stork in the Ciconia genus.  The extinct asphalt stork (C. maltha) was a North American bird, named for specimens found in the asphalt-like tar pits of California. Fossils of this species have been excavated from 34 sites in Florida, 2 sites in California, 1 site in Idaho, and 1 site in Mexico.  (The Mexican specimen was not conclusively identified.) The sites in Florida date from the early Pliocene to the late Pleistocene.  The asphalt stork, as a species, existed for at least 5 million years and likely occurred over a wide continental range for most of that timespan. Though it was closely related to the white stork, the asphalt stork probably occupied an ecological niche similar to that of the marabou stork (Leptoptilos crumeriferus).

Maguari stork  (Ciconia maguari) of South America

Video of marabou storks sharing a carcass with African vultures. Note the featherless head and neck.  This prevents contamination from toxic bacteria on the rotting meat they eat.

Video of marabou storks vs. a pack of mongoose.

The marabou stork scavenges and hunts the African plains but nests in woodlands.  They catch and eat small mammals, bird nestlings, reptiles and amphibians, and insects.  They also rely on carrion, garbage, and even feces.  They often follow vultures, waiting for them to tear open the carcasses before taking advantage of the meal. Stork bills are incapable of opening tough hides.  Species closely related to Old World vultures lived in North America during the Pleistocene.  The asphalt stork likely followed vultures and scavenged in  much the same manner as the marabou stork.  The extinction of North America’s megafauna led to the extinction of avian scavengers including teratorns, Old World vultures, and asphalt storks.

The asphalt stork was a big bird, reaching 4.5 feet tall.  It would have been entertaining to watch scavengers make carcasses disappear during the Pleistocene.  Giant short-faced bears ruled, but if they weren’t around, there would have been battles between coyotes and storks.  With their big bills, storks probably held their own against the smaller canids.

Reference:

Saurez, William

“The Records of Storks (Ciconidae) from Quaternary Asphalt Deposit in Cuba”

The Condor 2003

 

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2 Responses to “Pleistocene Storks of North America”

  1. Pinkney Says:

    Several of what appear to be links do not work.

  2. markgelbart Says:

    The links to youtube videos do show up on my blog viewed from my computer. I just bought a brand new computer. My old computer wouldn’t show links to youtube videos.

    I’ll have to see, if they appear on my wife’s laptop.

    You can cut and paste the links to your browser and that should work.

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