Birding without all my senses - April 2014

The last couple of weeks has proven to be a somewhat frustrating time which started with a heavy cold and led on to ten days with significant hearing loss. For most of the time I was house bound, but this last weekend I decided that I would venture out for some fresh air. Not wishing to travel far, I decided to start with a spot of patch birding and soon found out just how difficult it was to bird with very limited hearing.

I travelled to Botley Wood and could just about hear a common chiffchaff singing about three metres away, finding it, without any sense of direction proved to be even more difficult. I continued along the main track and was rewarded with very little, other than a wren, song thrush and the resident blue and great tits, but it was tough going. Fortunately, the warm spring sunshine made it ideal conditions for raptors. At least seven common buzzards were enjoying the thermals and sparring with each other.

Common Buzzard

The sparring buzzards took my mind off my deafness and as I tried to get some photos I noticed a common raven in amongst them. There has been a pair loitering in the area in recent weeks; this bird was making it very clear that they were still around, and they didn't like the buzzards being there.

Common Raven with two Common Buzzards

The expansion of the common buzzard in the UK has been one of the avian success stories of recent years. Unfortunately its success has been met with anger from the gamekeeping fraternity and there are increasingly regular reports of persecution. The aerial sparring between the buzzards and raven kept me occupied for a while, but they soon got bored with each others attention and drifted off.

Peacock Butterfly

The warm spring conditions were proving ideal for butterflies too. Brimstones were the most abundant with the bright yellow males patrolling the woodland edge. Peacocks too were fairly abundant, seeking out the blackthorn flowers to feed. I recorded two other species on the day, comma and an unidentified small white, which vanished before I could make out whether it was a green-veined or small white.

Great Crested Newt egg - This species is protected under European law
and therefore it is an offence to disturb them. I hold a Natural England licence
that allows me to survey for the species.

There are a few ponds dotted around the patch, and two of these support breeding great crested newts. Newts begin to return to ponds to breed in early March so I thought I would check out one for evidence. It took about 30 seconds to find my first egg and confirm that they were still breeding. A female great crested newt can lay as many as 250 eggs a season, and will lay around 10 a night as the air and water temperatures increase. This early in the season a female may only lay one or two eggs a night.

Streamer Moth

The warmer day and night-time temperatures has seen an increase in moth activity too. Two nights moth trapping in the garden produced 128 moths of 18 species. The majority of the species were ones that I had already trapped this year; the new species were streamer (above), blossom underwing and early tooth-striped (below).

Early Tooth-striped Moth

On the Lookout for Grasshoppers at Noar Hill - 15th August 2013

I had the opportunity to get out of the office yesterday in order to carry out an Orthoptera (Grasshopper and Cricket) survey at The Hampshire and Isle of Wight Wildlife Trusts Noar Hill Reserve. The main purpose of the visit was to check on the status of rufous grasshopper, a species that is known to be present, but had not been searched for recently. It is a species that is restricted to southern England on south-facing slopes of unimproved calcareous grassland, Noar Hill provides the ideal location for the species and has known to be present for many years.

Classic piece of chalk grassland at Noar Hill

The reserve was once the site of medieval chalk workings, but is now owned by the Wildlife Trust. In the spring and early summer it is carpeted with chalk downland flowers, including many species of orchid.

Harebell Campanula rotundifolia

I was hoping for a warm, still and sunny day, since these are the best conditions for Orthoptera surveys. Unfortunately it was quite windy and cloudy, so sunny periods were interspersed will long periods of shade, the temperature dropped considerably during these periods. Over 35 species of butterfly have been recorded at the site, and it wasn't long before we were seeing some of them. Chalkhill Blue was the first species recorded, keeping low in the vegetation but occasionally basking during a sunny interval. This species appears to have had a great year, as on the Wildlife Trusts Arreton Down reserve on the Isle of Wight, a few thousand individuals have been on the wing in recent days. A spectacular sight if you can get there to witness it!

Male Chalkhill Blue Lysandra coridon

Several common blue butterflies were also on the wing, although not as many as there were chalkhills, and the supporting cast included small heath, meadow brown, large and green-veined white and gatekeeper.

Male Common Blue Polyommatus icarus

Hemp-agrimony provided a rich source of nectar for more species, especially peacock, small tortoiseshell and a handful of clouded yellows that were scattered around the site. The latter proved incredibly difficult to photograph as they were easily disturbed, and were being blown around in the gusty conditions.

Peacock Inachis io

Underwing of Peacock Inachis io

Along the woodland edges silver-washed fritillary's, brimstone's and Comma's were also taking advantage of the rich nectar source provided by the hemp-agrimony.

Silver-washed Fritillary Argynnis paphia

Silver-washed Fritillary

Grasshoppers and crickets were proving difficult to locate since they were not really singing in the unfavourable conditions. Dark bush cricket was the first to be heard, and soon meadow, common green and field grasshopper had also been added. Roesel's bush cricket is one of those species which has expanded rapidly since being first recorded in the extreme south-east of the country. A handful of this species were recorded in the areas of taller vegetation, along with a few long-winged coneheads.

Sheltered sunny glade which proved to be a great location for
Rufous Grasshoppers

Eventually, after several hours of searching, a male rufous grasshopper was recorded in a sheltered glade in the east of the site. This species is one of the easier grasshopper species to identify due to the presence of a range of features, some of which are unique and are present on males, females and nymphs.

Male Rufous Grasshopper Gomphocerippus rufus

The grasshopper is generally brown in colour and usually has a reddish abdomen. The male has large club shaped antennae, similar to a butterfly, that are tipped white, these are diagnostic. They do also occur on females and nymphs but are not as pronounced, as can be seen in the pictures below.

Female Rufous Grasshopper

They also have pale palps, which are located by the mouth parts, and the call is like a clockwork toy unwinding. It is a late maturing species and with adults not usually found until late July, but they can survive until late November and even early December.

Rufous Grasshopper - Final instar nymph

Another species restricted to south-facing calcareous slopes in the south of England is stripe-winged grasshopper. It is quite a widespread species and can be quite common in some places. It has a very distinctive call that lasts about 10 to 20 seconds, it is very high pitched, starts with a hiss and then continues with a buzzing, metallic, pulsating sound.

Stripe-winged Grasshopper Stenobothrus lineatus

One distinctive feature is the enlarged central cells of the forewing, you may need a hand lens to see it, but it does tend to give the grasshopper the appearance of having a broad wing.

Enlarged central cells on wing of Stripe-winged Grasshopper

By the end of the visit eight species of Orthoptera had been recorded, including the target species and 13 species of butterfly. Not bad for a blustery afternoon in Hampshire.

Swifts (and bats) in the Belfry

I was recently contacted by a representative of the RSPB to see if I would be able to help resolve an issue with common swifts getting into a local church. This is an issue that has been happening over the last couple of years; and involves birds from the breeding colony at the church somehow getting into the church itself, becoming exhausted and dying. I was asked to attend because as well as breeding swifts, there are also roosting bats, and it was imperative that whatever plan of action was to be designed, it must help the swifts but not impact on the bats. The church dates from Norman times and is constructed with brick and flint, with a clay tiled roof, the side elevations of the bell tower are clad with wooden shingles and again it has  a clay tiled roof.

Dead Common Swift, Peacock Butterfly wings and Cluster Flies

I had to access the bell tower by-way of a long ladder and a small wooden door, which led to a small set of steps, and then into the first floor of the bell tower. I counted at least five dead swifts scattered in various locations in this area, along with several wings from peacock butterflies and hundreds of bat droppings and cluster flies Pollenia species.

Swift Head positioned upright on a Stone

There was also a reasonable amount of rodent activity in the bell tower, and some of the swift corpses had been eaten. Eerily, the head of one of the dead swifts was upright on a piece of plaster, I'm not really sure whether someone had positioned it like that or it had just ended up like that after being knocked/gnawed by rodents, probably the latter since its beak was missing.

Decomposed Swift with Flat Fly Pupae

I was rummaging around trying to find, where swifts were getting into the tower and how they were getting into the church. But as I was doing so I came across a decomposed swift with several small black pellets lying around it. I have seen these before when I have ringed swifts in the nest and know them to be the pupa of the flat-fly parasite Crataerina pallida which is host specific to swifts.

Crataerina pallida Pupa

The adult flat-fly is a blood sucking parasite which does not lay an egg, instead it broods the eggs internally, lays a fully formed larva that immediately starts to pupate. When the pupa hatches in the following year, it will try to seek out an adult bird or associate itself with a nest. 

I did manage to find how swifts were getting into the church, and have hopefully resolved that problem but will need to go back in the summer and see how they are getting into the bell tower. My aim will be to try a stop the swift becoming trapped in the first place, but in doing that I don't want to stop bats getting in, I will keep you posted....