House Martin diary 2011, Swift diary 2011

Screaming Swifts

Recent warmth has enabled the Swifts to feed on the abundance of flying insects, which gives them plenty of energy. Their flying in such conditions is spectacular, with screaming flocks passing the eaves at high speed throughout the daylight hours, literally starting at 4.30am and finishing at 10pm. Most of these screaming Swifts are non breeding birds who are looking for nest sites and in some cases joining existing colonies. We don’t know why they scream in tight flocks, it could be a social activity which bonds the colony or perhaps some form of courtship, we can only guess.
Recently these non breeders have been turning their attention towards the martin nests, hurling themselves at the mud structures to look in the entrances. The martins stay in their nests and defend them. Sometimes they even chase the Swifts in the air. It is unlikely that the Swifts would use the martin nests though this has occasionally been recorded. The martins added additional mud to their nest entrances and made the nests even stronger. Three out of the four pairs on the front of our house did this at the same time as a response to the increase in Swift activity. The slightly heavier Swifts were knocking small amounts of mud from the structures, mainly through the speed at which they landed.

We now have another pair of Swifts in residence. They have taken to a Swift nest box and visit frequently. They will probably build a nest during the rest of their stay and return to breed next May.

Swift looking at a House Martin nest on a fast pass
Swift perched on a House Martin's nest- copyright Jonathan Pomroy 2011
Swift prospecting nest box, landing needs practice! Copyright Jonathan Pomroy 2011
Swift prospecting nest box- copyright Jonathan Pomroy 2011
bird behaviour, Sketchbook

Nightjar and Turtle Dove

In the last two days I have managed to see two really special summer migrants, both very close to our home. After a failed attempt to see the eclipse of the moon on a cloudy evening I decided to try and find some Nightjars. It was nearly 11pm but twilight lingered in the North Western sky. I set out into likely habitat and began to clap my hands, as one does! This was an attempt to replicate the male Nightjar’s wing clapping display, almost immediately I was aware of a Nightjar approaching me, silhouetted against the dim sky it flew a couple of feet above my head on buoyant flight circling around me several times until it was sure I was not another Nightjar. It then settled close by and began its amazing churring song. This chilling sound is pure magic to listen to, perhaps more so when you are alone in near darkness in remote habitat Add to this the strange frog like calls of Woodcock roding flights and you have an night to remember.

A stone’s throw from where I saw the Nightjar early this morning I heard the beautiful purring calls of three Turtle Doves. They are extremely elusive when calling but I did manage a brief view of one in the top of a larch tree, enough time to glimpse its beautiful tawny and grey plumage before it flew. Turtle Doves are summer migrants to Britain have declined massively not least due to the fact that they are shot whilst on migration through Southern Europe.

I know I am extremely privileged to be able to observe these two fascinating birds so close to home.

Nightjar in flight- watercolour in sketchbook
bird behaviour, Sketchbook

Whinchats at Fen Bog, Yorkshire Wildlife Trust

A visit to the Yorkshire Wildlife Trust reserve Fen Bog on the North York Moors yielded excellent views of Whinchats. These beautiful summer visitors nest on the ground. They have suffered a sharp decline in the last two decades, possibly related to changes in their wintering areas in sub equatorial Africa. Fen Bog is a magnificent reserve at the head of the glacial meltwater channel of Newton Dale. In places the glacial peat deposits are 12 metres deep. I hope to return later in the year to see the dragonflies the reserve supports. These include Black- tailed Skimmer, Keeled Skimmer and Golden Ringed Dragonfly. The reserve is also known for its poulation of Small Pearl- bordered Fritillaries and an impressive list of upland mire plant species. If the wildlife is in short supply you can enjoy the steam trains running adjacent to the resrve on the North York Moors railway.

Male Whinchat (left with caterpillar)- watercolour in sketchbook
bird behaviour, Swift diary 2011

Mad Swifts!

On June 15th- 17th we were visited by many non breeding Swifts. These curious young birds queue up to look in the nest sites of the breeders. The breeders quickly return to their boxes and scream in duet at the visitors who hardly ever attempt to enter the nest site. They were also showing an interest in the vacant nest boxes though their early attempts at alighting on them are haphazard to say the least. There does seem to be another pair keen to find a site on our house and they seem particularly intersted in a hole under the pantiles. They may well build a nest this year and return to breed in 2012.
The flying displays have been spectacular with extreme high speed passes by the eaves, impossibly tight fast turns as if they are on a wire, then back past the eaves, screaming wildly especially when close to the potential nest site. This flying is so precise, millimetres at times from certain death, but they never miss and continue to thrill me, as they have every year since I first remember them flying round the eaves of my primary school.

Swift prospecting nest box- photograph by Jonathan Pomroy copyright 2011
Butterflies and moths

Eyed Hawkmoth

Eyed Hawk Moth- bird's eye view!
Eyed Hawk Moth

On the second night of testing my new moth trap which boasts a 125v mercury vapour bulb I caught this beautiful Eyed Hawkmoth. If attacked by a bird it reveals the blue eyes and rocks itself. This has been shown to be an effective deterrent against small birds. The caterpillars of this species feed on the leaves of wild and cultivated willows, sallows and apples. It is not uncommon in the Southern half of Britain, but extremely rare in Scotland. We are near the Northern edge of this species range here in North Yorkshire.

bird behaviour, Swift diary 2011

Swift nest

Swift nest- 8th June

The partial albino Swift and its mate have built a nest. I placed some of the material in the box to get them started but they have added their own too, such as the small oak leaf, grass pieces and the occasional petal all gathered in the air. They will probably lay one more egg in 48 hours then incubation will begin.  Swifts glue the nest materials together with their saliva. The nest is built onto a specially designed nest mould.

Butterflies and moths

Fun finding Fritillaries

Heath Fritillary near Porlock, Somerset (photograph copyright Jonathan Pomroy 2011)
Small Pearl- bordered Fritillary- Heddon's Mouth, North Devon (photograph copyright Jonathn Pomroy 2011)
Dark Green Fritillary, Heddon's Mouth, North Devon (photograph copyright Jonathan Pomroy 2011)
Dark Green Fritillary (Photograph copyright Jonathan Pomroy 2011)

These gorgeous butterflies were seen during a family camping holiday last week.