Month: September 2018

Sable Island’s Birds vs. Invertebrates

/ Laura Tuke / Leave a comment

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 arenarius, Orgyia 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)

Guide to Sable Island’s habitats and plants

/ Laura Tuke / Leave a comment

Look deep into nature, and then you will understand everything better – Albert Einstein

Sable Island, 250km from Halifax, Nova Scotia, Canada, is an island made entirely of sand. For approximately two thirds of the island runs a series of high dunes, flanked by two long sandy beaches, and are considered one of the largest dune systems in Eastern Canada. With the island experiencing a maritime temperate climate, the island sustains a range of habitat types, which include grassland, heath, sandwort, freshwater ponds, brackish ponds, and non-vegetated terrain.

Due to strong winds and a lack of soil, the island is treeless (apart from one) and is dominated by low-growing plant species. When on the island myself, one thing i loved, other than the vast variety of plant species, was the strong smell of lush green vegetation that would bombard my sense of smell everytime i was out and about walking.

Plant Species

In 2016, 183 vascular plant species were recorded on Sable Island, in which 34% were considered alien species.

Here’s a selection of different, more notable species that can be found on Sable Island:

Common species

Marram grasslandAmerican marram grass (Ammophila breviligulata)= Most common species

Beach peaBeach pea (Lathyrus japonicas var. maritimus)

Common yarrowCommon yarrow (Achillea millefolium var. occidentalis)

SandwortSea sandwort (Honckenya peploides sp. robusta)

Common wild roseCommon wild rose (Rosa virginiana)
Edible fruit and fragrant flowers

Lowbush blueberryLowbush blueberry (Vaccinium angustifolium)
Edible fruit

Large cranberryLarge cranberry (Vaccinium macrocarpon)
Edible fruit

New york asterNew York aster (Symphyotrichum novi-belgii)

Swamp smartweed

Stretch of swamp smartweedSwamp smartweed (Polygonum hydropiperoides)

Wild strawberryWild strawberry (Fragaria virginiana sp. glauca)
Edible fruit

Small flowered evening primroseSmall flowered evening primrose (Oenothera parviflora)

Blue flag irisBlue flag iris (Iris versicolor)

Hooded Ladies' tressesHooded ladies’ tresses (Spiranthes romanzoffiana)

Blue eyed grassBlue-eyed grass (Sisyrinchium angustifolium)

Hedge bindweedHedge bindweed (Calystegia sepium)

Seaside goldenrodSeaside goldenrod (Solidago sempervirens)

Also:
Pearly everlasting (Anaphalis margaritacea)
Creeping juniper (Juniperus horizontalis)
Common juniper (Juniperus communis var. megistocarpa)
Star-flowered false solomon’s seal (Maianthemum stellatum)
Black crowberry (Empetrum nigrum)= Edible fruit
Bayberry (Morella pensylvanica)= Edible fruit and aromatic leaves
Wand dewberry (Rubus arcuans)= Edible fruit
Threepetal bedstraw (Galium trifidum)

Juncus

 

Rushes and sedges

Baltic rush (Juncus balticus var. littoralis)
Canada rush (Juncus canadensis)
Slender rush (Juncus tenuis)
Jointleaf rush (Juncus articulatus)

Star sedge (Carex echinata)
Soft-stemmed bulrush (Schoenoplectus tabernaemontani)

 

 

Other grass species (Poa and fescue)

Red fescue (Festuca rubra)
Annual meadow grass (Poa annua)
Kentucky bluegrass (Poa pratensis)
Bentgrass (Agrostis scabra)

Introduced species

Curled dockCurled dock (Rumex crispus)

Black knapweedBlack knapweed (Centaurea nigra)

Also:
White clover (Trifolium repens)
Common heather (Calluna vulgaris)
Red clover (Trifolium pratense)
Common plantain (Plantago major)
English plantain (Plantago lanceolata)

Sable Island’s Only Tree

On Sable Island, due to the extreme conditions, there is only one living tree. This tree is a Scot’s pine, standing at a few feet tall. It was planted 50 years ago and can be found at the ‘Pine Tree Pond’ near Main Station on the island.

Here’s a couple of photos of the tree with the Sable Island Horse Project’s crew for the second half of this year’s summer field season:

DSC_0419DSC_0424

Introducing Sable

/ Laura Tuke / Leave a comment

We had been flying nearly an hour when a smudge first appeared on the horizon of the ocean stretching before us. Though shrouded in fog, it was clear that we were finally nearing  our destination, the remote island that would be my home for the next 4 weeks, Sable Island.

 

Flying

First recorded by European explorers during the early 1500s, Sable Island is a large crescent-shaped sandbar situated approximately 156km from the nearest landmass (Nova Scotia, Canada). Sitting on the edge of the eastern North American continental shelf, the island was probably formed from deposits left by retreating glaciers at the end of the last ice age. Currently at about 49km in length, 1.25km in width and up to 30m in height above sea level, the island is experiencing decreases in size over time and shifting eastwards.

Sable Island

Map images from Google Maps

Images from Google Maps

Though fabled by many, Sable Island is known for its abundance of wildlife and colourful history. In particular, the island is famous for being the ‘Graveyard of the Atlantic’, with 350+ shipwrecks resting off its shores, the latest originating from 1999 (the Merrimac). Despite people living on Sable from time to time since its discovery, during the 19th century it was these shipwrecks and the establishment of lighthouses and lifesaving stations that led to the start of continuous human presence on the island. The lifesaving stations persisted till they were decommissioned in 1958, but a meteorological station was set up at the start of the 20th century that is still functioning on the island today.

Sable shipwreck map

Map from the NS Department of Education

Today Sable Island is now under the management of Parks Canada, following its designation as a National Park Reserve in 2013. This designation recognises Sable for its impressive dune system and rich biodiversity, including endemic species and the world’s largest grey seal breeding colony. Despite this and the island’s many bird, invertebrate and plant species, you will find that the island’s population of feral horses is what captures most the public’s imagination. These horses were what I first saw when the green strip of Sable flanked by sandy beaches first came fully into view from the plane and its these horses that I was here to visit.

Following my first sight of the island, we were soon bumping down on to the landing strip on the island’s sandy south beach. After months of planning and much hard work, I had finally arrived!

Sable Aviation Plane

 

For Further Reading:

  • Sable Island: Explorations in Ecology and Biodiversity – Edited by Bill Freedman