Parish Nature Notes for April 2013 - John Wright

At last, spring seems to be making progress, but not before the first ten days of the month retained a wintry feel with cold easterly winds and winter thrushes (redwing and fieldfare) still searching for food in local fields. Fortunately, favourable winds from the south brought in many spring migrant birds around the middle of the month, but in late April, the weather turned cold again with northerly winds discouraging migration. Likewise, flowering plants and insects are still appearing later than is usual.

On the 6th April, despite the easterly wind, a woodlark was singing in Morden Bog and at Morden Park Lake one of the Great Crested Grebes was building a highly visible floating nest. A kingisher and grey wagtail added further interest. West of Sherford Bridge, by the track, flowering current bushes were starting to bloom and despite their unattractive smell to some humans, they are an important early source of nectar for both bumble and honey bees. Flowering current is an introduced garden shrub whose berries are then dispersed into the countryside by birds.  

Flowering Currant

Flowering Currant

Photograph: John Wright

After a misty start on the 10th April and more easterly winds, the morning improved with blue skies as I took a walk round Holton Lee. Numerous chiffchaffs, a dartford warbler and woodlark were all singing yet it was still possible to find redwing and fieldfare. On shallow pools by Lytchett Bay, several redshank, a greenshank and a few black-tailed godwit were feeding. Further on, teal were calling, shelduck could be seen and a group of four sika stags, one with a cream-coloured coat were only partially concealed within the reedbed. As I cast an eye over the Wareham Channel, the gull islands were teaming with black-headed gulls and on the water nearby were four great crested grebes. As I watched them through binoculars, I was treated to my first sandwich tern of the year flying above them. These splendid birds have long black and yellow-tipped bills and are normally first noticed by their strident 'kirrik' calls.

Sandwich Terns

Sandwich Terns

Photograph: John Wright

After exceptionally heavy rain overnight, my regular walk round Wareham Forest/Morden Bog on the 12th revealed lots of chiffchaffs, but still no blackcaps. Normally their beautiful warbling song can be heard from late March/early April. However, at Morden Park Lake about a dozen swallows zipped low over the water catching emerging insects and perhaps 50 feet above the water a similar number of house martins were also feeding. After a while the rain resumed but whereas the swallows continued feeding, the house martins soon disappeared. Meanwhile, both Great Crested Grebes inspected their floating nest and I was lucky to see grey wagtails and kingfishers once again.

Swallows

Swallows

Photograph: Ken Dolbear

A short walk through the southern half of Morden Bog on the 16th confirmed that the flood of migrants was truly underway at last as a blackcap burst into song, tree pipits sang from short conifers and the beautiful downward cascading songs of willow warblers reached my ear from the nearby willow trees. Although superficially similar to the chiffchaff, the willow warbler has a far more pleasing and complex song. One of a number of subtle differences between the two species is that whereas chiffchaffs have dark legs, the willow warbler has much lighter coloured legs (see photo).

Willow Warbler

Willow Warbler

Photograph: ken Dolbear

By the 19th a similar walk in Morden Bog produced the same selection of migrants, together with a lesser redpoll calling overheard and my first cuckoo of the year. (Later in the month cuckoos were heard on several occasions in Morden Bog, Wareham Forest and on Sandford Heath). As I left Morden Bog by the B3075 near Forest Edge I saw my first hedgehog of the year - unfortunately a dead one, having been hit by a vehicle.

Hedgehog

Hedgehog

Photograph: John Wright

The 20th was mild and sunny with a breeze from the south and as I walked through wareham Forest and Morden Bog, chiffchaffs and more Willow warblers, tree pipits and blackcaps were all moving through. At Morden Park Lake the sight of a single feral greylag goose made me wonder whether a second bird was out of sight on a nest, as I had seen a pair together at the lake on 14th March. A single mute swan was also present - an infrequent visitor to this waterbody. Nearby, close to the Sherford River I saw what I believe to be the only patch of wood anemones growing wild within the parish of Wareham St Martin. These attractive indicators of ancient woodland rarely produce fertile seed and spread very slowly through root growth - it is claimed no more than 6ft in 100 years!

Wood Anemones

Wood Anemone

Photograph: Ken Dolbear

On the same walk, a noticed a green tiger beetle in Morden Bog and a couple of small tortoisehell butterflies. These once familiar garden butterflies were exceptionally scarce a few years ago but are, perhaps, starting to make a comeback. Various species of flies and other insects are known to lay their eggs near or in the caterpillars and their grubs then feed on and ultimately kill the caterpillars. Weather conditions can also affect the food quality of the nettles on which the caterpillars feed and therefore affect the size of the next generation of butterflies.

Small Tortoiseshell

Small Tortoiseshell

Photograph: Ken Dolbear

The 23rd was a pleasant sunny day and in walking west from Organford towards Sherford bridge there were further signs of spring as several bright yellow male brimstone butterflies appeared and also a somewhat lighter-coloured female brimstone. Within old hazel coppice woodland close to the Sherford River wood sorrel was showing its mauve-veined small white flowers and trefoil leaves. In nearby trees I heard and then saw a marsh tit and soon afterwards was very lucky to see a migrating wood warbler feeding in a birch tree. This rather dumpy and apparently short-tailed close relative of the chiffchaff and willow warbler gave a very characteristic trill as it went on its way.

Wood Sorrel

Wood Sorrel

Photograph: John Wright

The return of a very cold wind from the north on the 27th encouraged me to wrap up well for my Wareham Forest/Morden Bog walk and although I saw and heard a selection of spring migrants, the sighting of two pairs of crossbills seemed more in keeping with the wintry weather. By the end of the month I heard that it had been the coldest April for 24 years. Nevertheless, the warm chestnut colour of flowering bog myrtle in Morden Bog was a welcome sight. This shrub, sometimes called sweet gale, has a pleasant resinous smell and has been used in making scented candles, in the production of beer and also as an insect repellent.

Bog Myrtle

Bog Myrtle

Photograph: John Wright

And finally, a walk in Morden Bog and Great Ovens on the 29th with sunny conditions again produced further signs of spring. Small pink spikes of lousewort were starting to appear on the heath, my first hobby of the year flew back and forth high over Morden Bog and while linnets sang from gorse bushes, two cuckoos added to the atmosphere. The sun brought out more of the overwintering peacocks and brimstone butterflies and as I neared home I saw my first green-veined white butterfly of the year. This butterfly had recently hatched from an overwintering chrysalis and the name 'green veined' refers to the underside of the wing whose veins have additional dark scales, giving them greater emphasis. My specimen was nectaring on a dandelion flower but the females favour damp conditions and lay their eggs on plants such as cuckooflower and garlic mustard.

Green-veined White

Green-veined White

Photograph: Ken Dolbear