Owl

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.

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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)

Barmy about barn owls: Owl pellets

/ Laura Tuke / Leave a comment

Currently we have at least one pair of resident barn owls on our 250 acre Dairy Farm, with one notable pair being seen amongst our farm buildings and fields closest to the centre of the farm.

On 26/05/16, I found a barn owl pellet within our straw barn, which was at least 1 month old. Through my interest in barn owls and the other species living on our farm, I then soaked the pellet and teased it apart to find the small mammal bones within.

The pellet was filled with lots of bones, such as shoulder blades, hipbones, femurs and humeri.

Selection of small mammal bones
Shoulder blade
Shin bone (tibia/fibula)
Hipbone (pelvis)
Femurs and Humeri

From the skulls and jaw bones found in the pellet, I was able to identify the four skulls to species level. Two skulls were from common shrews…

Common Shrew mandible
Common Shrew skull
Common Shrew skull

…and two skulls were from field voles.

Field Vole mandible
Field Vole skull

It was really interesting to be able to get closer to the small mammals that can be found on our farm, whatever the level of species abundance. It also gave me the opportunity to brush up on my skull and bone identification skills with the help of an RSPB owl pellet identification guide, which can highly recommend to others

(https://www.rspb.org.uk/Images/Owlpellets_tcm9-133500.pdf). 

I also recommend to others to get out at this time of year and to find your own owl pellets to learn more about the owls and prey species in your local area.

Winter into spring: January on the farm

/ Laura Tuke / Leave a comment

January is often a cold and bare month, no leaves on the trees and an atmosphere of dormancy. But I say, if you just look closely enough, beauty is still there to be found.

January is the month when snowdrops begin to spring from the earth, hinting at the new life that is to come with spring.

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Trees stand bare and leafless, showing off their magnificent skeletal shapes.

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The last of the autumn’s berries still laden the hedgerows throughout January this year, in particular bright red rose hips.

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As well, windfalls still lie beneath the apple trees from last years crop, ready for the taking. Badgers make frequent trips to the orchard to take advantage of the food source, and all that can be seen as evidence of these raids, are the discarded left overs of apples out in the nearby fields.

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Many gulls feed on the farmland fields during the daytime, with the flocks being mainly made up of herring gulls and great-black backed gulls. Usually also during the winter, flocks of starlings feed around the farm, but they only appeared for the first time this winter, near the beginning of January. Currently they can be seen flocking on the fields to feed or chattering away in the trees around our farm buildings. As well, iconic of this time of year, fieldfares and redwings can be seen feeding in the fields.

During the daytime, lots and lots of birds visit the bird feeders in the garden, to feed on peanuts and mixed seed. These bird species include, blue tits, chaffinches, great tits, goldfinches, house sparrows, dunnocks and great spotted woodpeckers.

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During the night at this time of year, tawny owls can be heard calling, as they attempt to rekindle pair bonds before the breeding season begins from February onwards. Also, female foxes can be heard calling to males, as they become receptive for mating.

Some mornings are woken up to a frost covered landscape. It makes things look particularly magical with the ground sparkling in the morning sunshine. With changes in winter weather though, these mornings have become rare in Dorset during this winter.

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This January, change is in the air. Not the change of tradition, but change that feels wrong. Daffodils began to shoot from the beginning of January and primroses appeared in the hedgerows.

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My highlight of January 2016 has to be, seeing a lone kestrel hunting close to our house everyday. A magnificent sight to see a bird hovering, still in mid air, before swooping down to catch a vole.

Brilliant barn owls

/ Laura Tuke / Leave a comment

When I arrived back home a week ago from my first year of uni, I was told that my friend had seen a pair of barn owls on my home farm. These owls were seen to be using a barn owl box that had been put up by my Dad a couple of months ago. As barn owls had been seen by my family and myself on our dairy farm before, this year my Dad had decided he wanted to give them a helping hand, in the hope that they would use our box to breed. The news that it was possibly being used already, excited me. Consequently, I wanted to see for myself that the box was actually in use, and planned a barn owl box stake out the following evening.

I headed to where the box was situated at 20:45 and positioned myself in a cubicle barn across from the box, where I could look through a gap up at the box and surrounding possible perches. Patiently I waited, with no sign of either adult birds, though I could hear an individual screeching noise coming from the box, which made me aware that an adult bird was present.

After a period of only blackbirds, magpies and pheasants being heard, I heard a screech come from the nest box, followed by an adult female barn owl flying out of the entrance hole of the box, and landing on a metal roof truss a couple of metres from the box. After a few minutes of the female scoping her surroundings, she flew a couple of metres further, perching on a second roof truss. There she preened her feathers, stretched and defecated, before returning back to the nest box.

It was amazing to actually got to see the female up close, closer than I had ever seen one before. From this sighting, I could deduce that the female was going through the processes of incubation, though I cannot say at what point the female started sitting. On my walk back home from the barn, I disturbed the male who had been sat on a bank of grass not too far off from the barn.

I am looking forward to keeping an eye on the pairs’ process, and a family friend who is a licensed bird ringer is hoping to make a visit to us at the end of June to check the barn owl box. If there are chicks and they are big enough, he is hoping ring them. I cannot wait!