Three of us, Ray Staszko, Keith Lowe and I, visited Sambro Island last Monday. I gave my companions just 24 hours notice since an end of month trip must coincide with lack of fog, fair weather, and favourable winds. It is a tricky affair and because it's tricky I've missed visiting the island for the last two years due to fog or a strong south-westerly wind. As it was there was morning fog over Portuguese Cove but thankfully it was absent at our departure point, Sambro Head, and mostly absent over Sambro Island.

Sambro Island

The aerial photo above shows the appropriate areas to walk when on the island. The white areas are solid rock and this is where one should be most of the time. There are a few well trudged trails through the grass which are OK but the large green/brown areas on the north and south side of the island are definitely "feet off". Arctic Tern are ground nesters and scratch out a space of ground to lay their camouflaged eggs so it would be easy to destroy or expose the location of a nest by trudging about in the grassy areas. The same reasons apply for not walking on sandy and gravel areas.

When we arrived at Sambro Island at 8:30AM and the captain took us on a clockwise loop of the island I witnessed a life event, although for mariners of all types this is no doubt witnessed regularly. It was a fog bow! According to Wikipeida:

A fog bow is a similar phenomenon to a rainbow; however, as its name suggests, it appears as a bow in fog rather than rain. Because of the very small size of water droplets that cause fog—smaller than 0.05 millimeters (0.0020 in)—the fog bow has only very weak colors, with a red outer edge and bluish inner edge.^[1]

In many cases when the droplets are very small, fog bows appear white, and are therefore sometimes called white rainbows. This lack of color is a feature of a fog bow which distinguishes it from a glory, which has multiple pale colored rings caused by diffraction. When the droplets forming it are almost all of the same size the fog bow can have multiple inner rings, or supernumeraries, that are more strongly colored than the main bow. According to NASA:

The fogbow's lack of colors is caused by the smaller water drops ... so small that the wavelength of light becomes important. Diffraction smears out colors that would be created by larger rainbow water drops ...^[2]

A fog bow seen in clouds, typically from an aircraft looking downwards, is called a cloud bow. Mariners sometimes call fog bows sea-dogs.

FogbowFogbow The Sambro Island Light is the oldest original lighthouse in North America. For the benefit of my American friends replacement lighthouses don't count for aging an original structure. The island itself is a well established nesting colony of Arctic Terns and Black Guillemots and should be protected as a conservation area except for occasional expert, guided and well controlled groups during the breeding time. Otherwise, it should be closed completely during June and July.

When at the light itself you'll see two cannons. These cannons were fired in lieu of fog horns before fog horns were available.

We moor at the the island in a narrow inlet that faces directly south west(see aerial photo above) which is why strong south-westerly winds are trip killers. The old mooring eyes are still present and the boat can be pulled up tight to the rock which has a shear vertical face dropping into deep water. There is an old shack here which might have been used for temporary storage when unloading supplies for the lightkeeper and his family. It also makes a superb blind for photography. A great pile of garbage from previous and probably recent visitors was left here, a shame.

Sambro Island Gas House

The Arctic Tern is easily recognized by it's all red bill and extra long tail. When at rest the tail extends beyound the wing tips.

The tail can also be observed in flight, a spectacular vision. Interestingly the Arctic Terns although constantly dive bombing the gulls ignored the humans.

The principle enemy of the Arctic Tern is the Great Black-backed Gull which also nests on the ground. I walked past a nesting Black-backed Gull not a metre from me while I was on one of the main trails.

On the same trail near the shore I stood briefly on a rock when out popped a Black Guillemot from under the rock. It's primarily a cavity nester where it wedges into rock crevices and can easily defend its nest.

Black GuillemotBlack Guillemot

Black GuillemotBlack Guillemot

Black GuillemotBlack Guillemot

Black GuillemotBlack Guillemot

Black GuillemotBlack Guillemot

Another common nesting bird is the Spotted Sandpiper. We must have been close to its nest since it appeared to be trying to divert our gaze elsewhere.

Spotted SandpiperSpotted Sandpiper

I have lots of other photos from this trip but to see them all you should visit my website, and look under birds/shorebirds, birds/swimming birds and birds/aerialists.

It was a magnificent day with light winds, no biting insects, excellent company and with one missed opportunity. When I was on the other side of the island observing what I believe was an Arctic Tern nest in a gravel space between rocks I heard Ray bellow for my attention. I arrived at the south west corner of the island just in time to miss two Atlantic Puffins which both my compatriots had already photographed. Next time!

A compete e-bird record was posted by Keith so I won't repeat that material.

I was exhausted after hobbling around on a gimpy knee and looked forward to an afternoon of rest.