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| (Northern) Wheatear - Portland Bill, Dorset, UK |
A visit to Portland Bill rarely disappoints, and today's sunny weather was enough to lure the family down for a walk, lunch and some wildlife watching. Reports of good numbers of Wheatears on the Portland Bird Observatory website (link) meant that this neat migrant was top of my wish list. And it didn't take long to spot one, perched on a roadside boulder near the Bill car park. I would have to wait a little bit longer for a decent image, however; the above photo was taken on the coast path heading up the east side of the 'island' (actually not an island, but that's what everyone calls it) just north of the beach huts. It was one of an estimated 10-15 that I saw on the fields and in the nearby quarries. This is good news: the Spring migration is up and running.
One of Portland's great selling points is the diversity of wildlife that can turn up. Whilst enjoying the background chatter of Skylark song and watching Rock Pipits flit along the shoreline we noticed a Grey Seal's muzzle sticking out of the water, close in to the shore (below). A fine set of whiskers were on display.
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| Grey Seal 'bottling' - Portland Bill, Dorset, UK |
This common behaviour is known as 'bottling' - as it apparently resembles a floating bottle - and it allows the seal to rest, and even sleep, with minimal exertion. Its eyes (not visible in this photo) were near to the waterline, and may even have been shut. It may have heard us, as it raised its head up and gave us a rather penetrating stare (below) before diving.
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| Grey Seal 'bottling' - Portland Bill, Dorset, UK |
I've written before about Portland's Wall Lizards (see a blog about recent sightings here and a more detailed one about identifying British lizards here). These non-native reptiles are a charming and visible addition to the local fauna, and it's always great to have an encounter. The jury remains out as to whether they have a harmful effect on native reptiles, by the way; this certainly can't be ruled out. But, as I've previously commented, they appear to occupy a distinctly different 'niche' to Common (or Viviparous) Lizards their nearest likely competitor, while their colonies on the south coast of England are well-separated from the heathland domain of the threatened Sand Lizard.
Anyway, we went looking for Wall Lizards in one of the quarries next to the coast path on the eastern side of the island, a place with several previous sightings. Although the day was sunny, a cool easterly breeze wasn't ideal for these ectothermic creatures - ectothermic meaning that they rely on external heat sources. On that point: reptiles are commonly called 'cold-blooded' - I've done it myself - but this isn't fully accurate. To be properly active, they need to reach a certain blood temperature, which in Britain is around 25-30 degrees Celsius (Inns, 2009). Obviously, such temperatures cannot be guaranteed in our chilly latitudes, even sometimes during the British summer. Today on Portland it was considerably colder, perhaps 15 degrees at the most. However, reptiles are very good at extracting what heat they can from the surrounding environment, mainly by basking in the sunshine but also by flattening themselves against warm surfaces. This morning, the best place to look for Wall Lizards was therefore in a sunny but crucially sheltered corner of the quarry. And that's where we found a couple:
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| Common Wall Lizard - Portland, Dorset, UK |
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| Common Wall Lizard - Portland, Dorset, UK |
The mottled pattern on the back suggests that both lizards are males, although only the second one was showing the characteristic yellow-green colour that accompanies the breeding season. Wall Lizards, and indeed Common Lizards, are relatively quick off the mark in that regard compared to Sand Lizards which will usually not begin to mate until April at the earliest. (As it happens, I saw my first Sand Lizard of the year while surveying on the Purbeck Heaths this week; it was a male without any evidence of green colouration.)
Before leaving the island we revisited the Wall Lizard colony at Cheyne Weares (further up the island's east side) that was the subject of my previous blog. By now, the sun had moved into the western sky and much of the roadside wall was in shadow. But we still found eight individuals making the most of the sunshine, including these two:
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| Wall Lizard - Cheyne Weares, Portland, Dorset, UK |
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| Wall Lizard - Cheyne Weares, Portland, Dorset, UK |
The obvious stripes on the back of each individual suggest that they are both females - although please let me know if you disagree. Also present in this colony were several much smaller lizards, likely last year's juveniles that have successfully overwintered.
As ever, Portland delivered on the wildlife front - and we had an excellent lunch at the Lobster Pot, too. With Spring now getting into gear, it won't be long before I'm back.
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| Portland Bill, Dorset, UK |
References
Beebee, T. & Griffith, R. (2000) Amphibians and Reptiles (New Naturalist Series) London: HarperCollins.
Inns, H. (2009) Britain's Reptiles and Amphibians Wildguides
Text and images (c) Mike Hetherington
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