Friday, 30 June 2017

Cnoc Salltraim ...

Cuckoo (Cuculus canorus)




C. canorus is a familiar herald of spring and a species that is thinly distributed over a wide breeding range throughout most of Britain, Europe and the Palearctic. It is a fairly common but rapidly declining summer visitor to Sussex, where the males commence singing soon after their arrival; typically in early April. Recent satellite tracking technology has shown that the males usually leave the UK to their wintering area south of the Sahara only a few weeks after first arriving here in the spring.

C. canorus has a well-known breeding strategy as a brood parasite, laying its eggs in the nests of other birds; typically those of the Dunnock (Prunella modularis), Meadow Pipit (Anthus pratensis), Pied Wagtail (Motacilla alba) and Reed Warbler (Acrocephalus scirpaceus) in the UK. The female, who will specialise in one particular host species, will only ever lay one type of egg and will always target her egg-laying appropriately. The genes for egg pattern and colour are thought to be carried on the female chromosome, so they are passed down from mother to daughter regardless of who the female mates with. This means that a Cuckoo targeting a Reed Warbler always produces eggs with a Reed Warbler pattern and she knows which nests to target thanks to the process of imprinting. As a young chick, she will have learned to recognise the song and appearance of her foster mother; and as a returning adult she will seek out the nests of females that match this mental image and lay her eggs accordingly.

The above images of a female were recently taken on North Uist in the Outer Hebrides.

References:

Yates, B. (2014). Common Cuckoo. The Birds of Sussex. Thetford: British Trust for Ornithology (BTO) Books on behalf of the Sussex Ornithological Society, pp. 360-361.
Whitcomb, P. (1996). Cuckoo. Birds of Sussex. Sussex Ornithological Society, pp. 358-359.


Saturday, 24 June 2017

In context …

Purple Emperor (Apatura iris)


A. iris is best seen through the early morning and again during the late afternoon, when the males come down to the ground, on hot humid days, to take in nutrients from damp earth and animal droppings. They are also partial to human sweat - a key component of Emperor watching - and readily land on observers. Despite this ‘grounding’ behaviour, both males and females spend much of their time resting or feeding high within their arboreal home and out of sight.

The above image shows a male feeding on honeydew high in the oak canopy.

More at:

Thursday, 22 June 2017

Cause and effect …

Purple Emperor (Apatura iris)








2017 is turning out to be a very early season for many species of butterfly. My first sighting of iris this year came on Saturday, 17th June when I recorded three males and a female in Chiddingfold Forest. On the same day, a friend recorded four males in a nearby area of the same forestry complex. Our joint feelings were that they’d been out for a maximum of 48 hours. The earliest I’ve ever recorded iris is a sighting of a solitary individual on 12th June 2015. However, for whatever reason(s), that same year I didn’t see another in my local woodlands until 4th July. A highly unusual and freak encounter or are things changing?

One must always be cautious when claiming ‘cause and effect’ with regards to the timing of a butterfly’s flight season. One thing that is evident is that the vast majority of our butterfly species have demonstrated a clear and unequivocal response to climate warming, with their average first appearance dates and abundance peaks now being significantly earlier than they were (Blencowe and Hulme, 2017). The flight periods of most of our species, measured in terms of first annual appearance, the first appearance of subsequent broods (in polyvoltine species), and abundance peaks, have moved forward by between one and three weeks in 20 years, with an average based on 40 species being about 13 days. Interestingly, a few species registered very little response to a warming climate; these included Meadow Brown, Gatekeeper, Silver-washed Fritillary and Brown Hairstreak (Blencowe and Hulme, 2017).

These days iris usually flies from late June to early August, with most adults emerging over a three week period; the average flight season recorded between 2010 and 2014 in Sussex was 28th June to 9th August. However, during this five-year period, two late years (by modern standards) were recorded. The typical first appearance date during the 21st century is now a little earlier, usually falling between the 20th and 25th June. During the later decades of the last century iris usually emerged in early July, so the flight period has shifted forward significantly, by at least two weeks (Blencowe and Hulme, 2017).

The above images show (i) a male from 17th June 2017, (ii) a male from 23rd June 2017, (iii) a female from 19th June 2017, and (iv, v, vi and vii) four images of two females from 21st June 2017.

More at:

Blencowe, M. and Hulme, N. (2017). The Butterflies of Sussex. Newbury, Berkshire: Pisces Publications on behalf of Butterfly Conservation (Sussex Branch), pp. 27, 170-179.

Sunday, 18 June 2017

Loch Fada na Gearrachun …

Short-eared Owl (Asio flammeus)



A. flammeus is a scarce winter visitor and passage migrant to my home county of Sussex. Wintering birds are found mainly on the coastal plain, especially around Chichester and Pagham Harbours, on the Pevensey Levels and at Rye Harbour. They also occur in smaller numbers on the Downs and in the river valleys of the Adur, Arun and Ouse. Autumn migrants are generally first seen in Sussex in late August or early September where they typically continue their journeys south to more southerly wintering grounds. If weather conditions are favourable and prey numbers are high, birds arriving from late September onwards are likely to remain in Sussex for an extended period and may settle down and winter in suitable areas.

An estimate of the Scottish population suggested 780 to 2,700 breeding pairs (1,000 - 3,500 pairs for the UK) in the late 90’s; although this is thought to be one the most unreliable estimates for any raptor or owl species. A more recent estimate (2013) for Britain is 610 to 2,140 pairs. Some experts consider the lower end of these ranges to be the more likely and are concerned that the species may have shown marked declines during the past two decades.

The above images from North Uist in the Outer Hebrides.

References:

Green, D. (2014). Short-eared Owl. The Birds of Sussex. Thetford: British Trust for Ornithology (BTO) Books on behalf of the Sussex Ornithological Society, pp. 369-370.
Patton, S.J. (1996). Short-eared Owl. Birds of Sussex. Sussex Ornithological Society, pp. 366-367.

Wednesday, 14 June 2017

Early bird ...

North Uist, Outer Hebrides

The rewards of an early morning approach ...




The first two images taken before 6am ….

More at:

Saturday, 10 June 2017

Balranald …

North Uist, Outer Hebrides, 13 to 27 May 2017






Balranald Nature Reserve incorporates the most westerly point of the island of North Uist, the Aird an RĂ¹nair peninsula, looking out to the Monach Islands and the magnificent St Kilda archipelago. It is a Site of Special Scientific Interest (SSSI) and is designated as a Wetland of International Importance (Ramsar).

This beautiful Hebridean reserve comprises 658 hectares [1626 acres] of rocky headland, islands, sandy bays, dunes, grasslands, freshwater lochs, fen and the flower-rich species diverse machair. Machair is a rare, bio-diverse coastal grassland, unique to the north-western fringe of Europe. It is listed on Annex 1 of the EU Habitats Directive, and occurs over a total global area of just 19,000 ha, with 70% of this in western Scotland, mostly on the offshore islands, and the remainder in western Ireland. These habitats support internationally important populations of many wading and farmland bird species, notably the Corncrake Crex crex. They also protect a number of important plant species and a variety of other wildlife, including the rarest UK bumblebee, the Great Yellow Bumblebee Bombus distinguendus.

The unmanned RSPB visitor information centre explains the importance of traditional crofting agriculture for rare birds and other important wildlife. A few images from my recent visit above.

More at:

Friday, 9 June 2017

Stinky Bay …

Iceland Gull (Larus glaucoides)




Despite its vernacular name, the Iceland Gull does not breed in Iceland but in Arctic Canada and Greenland. In Britain, it occurs mainly in the north and west during winter. Numbers appearing in Britain fluctuate considerably and large influxes occasionally occur, possibly associated with severe northwesterly gales. L. glaucoides is a very scarce winter visitor and passage migrant in Sussex; around 89 individuals in total being recorded during the winter periods of 1961/62 to 2010/11. Prior to this only 26 had been recorded in the county. Most records relate to individual birds observed in late winter or spring. The above pictures of a second summer bird were all recently taken during very overcast conditions on Benbecula in the Outer Hebrides.

References:

Newnham, J. (2014). Iceland Gull. The Birds of Sussex. Thetford: British Trust for Ornithology (BTO) Books on behalf of the Sussex Ornithological Society, pp. 324-325.
Newnham, J. (1996). Iceland Gull. Birds of Sussex. Sussex Ornithological Society, pp. 324-325.

Thursday, 8 June 2017

Bucket list ...

Eurasian Otter (Lutra lutra)


It’s taken me a very long time but I’ve finally managed to see and get a reasonable photograph of an Otter in the wild in the UK. The above male was recently spotted hunting for flatfish and crabs in a sea loch located on North Uist in the Outer Hebrides. As luck would have it, as the prevailing weather conditions really weren't very good, he decided to come out of the water and on to a small grassy bank to pause for a few moments before returning back to his watery domain.

All I can say is, "well happy" …

Tuesday, 6 June 2017

Amongst the machair …

Corncrake (Crex crex)




This charismatic and generally very secretive bird is best recognised by its rasping call and slight twitching of leaves as it moves effortlessly through tall grasses and herbage in order to stay concealed in cover. Although relatively easy to hear it is not always easy to see - its voice carrying some considerable distance easily disorientating the expectant observer.

C. crex is listed in Birds of Conservation Concern 4: the Red List for Birds because of major population declines both historically and recently. Once widespread in Britain, C. crex has undergone a devastating national decline and range contraction since the 19th century due to the change in the way grassland is farmed. Earlier cutting of hay, increased mechanisation of the hay cut and the switch to silage meant that nests, chicks and even adults were killed. Its rasping call has not been heard regularly in Sussex since breeding ceased in the early 1940s. Numbers in the UK reached a low point of 489 singing males concentrated in the remaining core areas of the Outer Hebrides and Orkney in 1993. Their fortunes have at least been partially reversed by the recent conservation efforts of the RSPB and local crofters in the Western Isles and by a reintroduction scheme in the Nene Washes, Cambridgeshire.

The above birds were recently photographed amongst the stunning scenery of the Outer Hebrides.

More at:

Hobson, J. (2014). Corncrake. The Birds of Sussex. Thetford: British Trust for Ornithology (BTO) Books on behalf of the Sussex Ornithological Society, pp. 216.
Kelly, R. (1996). Corncrake. Birds of Sussex. Sussex Ornithological Society, pp. 220-221.