Sable Island’s Birds vs. Invertebrates

The wonders of nature are endless – Walt Disney

When people think of Sable Island, they may think of a windswept island of sand, the island’s famous feral horses, or its involvement in maritime stories. More overlooked is Sable’s vibrant collection of fauna and flora, the latter having previously been touched upon in my ‘Guide to Sable Island’s habitats and plants’. When considering Sable’s fauna though, the most abundant can be split into its birds and its invertebrates.

Birds

Juvenile gull

Over Sable’s recorded history, at least 340 bird species have been observed on the island. These species span from American kestrel (Falco sparverius) to ruby-throated hummingbird (Archilochus colubris) to red-breasted nuthatch (Sitta canadensis), the last being one species I got to see myself this summer on Sable.

More than 45% of bird species that have been observed on Sable though, are termed as vagrants. This means that they have strayed from their usual range, for example arriving on the island due to being blown off course by strong winds during migration. As a result, I had the pleasure of seeing one iconic species during my stay this summer; a snowy owl (Nyctea scandiaca), floating like a ghost between the island’s dunes.

Snowy owl 3

Snowy Owl

Many species also use the island as a stopover site during their migration, for example waders, raptors and warblers. Regular migrant species include willet (Catoptrophorus semipalmatus), sooty shearwater (Puffinus griseus), grey-cheeked thrush (Catharus minimus) and:

Yellowlegs

Yellowlegs

Female American Golden Plover and sandpiper

Female American golden plover (Pluvialis dominica) (sandpiper in foreground)

Ruddy turnstone

Ruddy turnstone (Arenaria interpres)

Sanderling

Sanderling (Calidris alba)

Whimbrel

Whimbrel (Numenius phaeopus)

White-rumped sandpiper

White-rumped sandpiper (Calidris fuscicollis)

Of the 340+ species seen on Sable though, more than 30 have been recorded as breeding on the island. Regular breeders include:

  • Arctic tern (Sterna paradisaea)
  • Common tern (Sterna hirundo)
  • Roseate tern (Sterna dougallii)
  • Herring gull (Larus argentatus)
  • Great black-backed gull (Larus marinus)
  • Ipswich sparrow (Passerculus sandwichensis princeps)= endemic
    • Subspecies of Savannah sparrow and of conservation concern

Ipswich sparrow

  • Leach’s storm-petrel (Oceanodroma leucorhoa)
  • American black duck (Anas rubripes)
  • Mallard (Anas platyrhynchos)
  • Red-breasted merganser (Mergus serrator)
  • Northern pintail (Anas acuta)
  • Least sandpiper (Calidris minutilla)
  • Spotted sandpiper (Actitis macularia)

Juvenile spotted sandpiper

Invertebrates

In comparison to the 340+ bird species that have been recorded on Sable Island, 875+ invertebrate species have been identified on and in its marine proximity. Species include the monarch butterfly (Danaus plexippus), painted lady (Vanessa cardui), seven-spot ladybird (Coccinella septempunctata), and round-tipped cone-headed grasshopper (Neoconocephalus retusus).

Six spot ladybird

Seven-spot ladybird (Coccinella septempunctata)

Six spot ladybird larvae

Seven-spot ladybird larvae

Sable Island also has some endemic invertebrate species. These include the Sable Island leaf beetle (Pyrrhalta sablensis), the Sable Island sweat bee (Lasioglossum sablense)and three moth species (Agrotis arenariusOrgyia leucostigma sablensis and a Papaipema species).

Though I did not get enough time on Sable Island to delve too deeply into the world of the invertebrates, I did enjoy seeing new species and identifying the many caterpillars I saw, such as:

Apple sphinx moth caterpillar

Apple sphinx moth caterpillar (Sphinx gordius)

Virginian tiger moth caterpillar

Virginian tiger moth caterpillar 2

Two variants of Virginian tiger moth caterpillars (Spilosoma virginica)

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