Summer migrant at last!

The weather last weekend certainly suggested that spring had sprung and the many signs of the changing seasons about such as flowering Wood-Sorrel and active Bee-Flies supported that fact. However despite the beautiful sunny weather, by yesterday morning I was still yet to see a summer migrant this year!

Early yesterday morning I spent over an hour at the beautifully serene and calm Hedgecourt Lake waiting for a particular species I was hoping to see arrive. Ospreys are apparently seen here every spring and autumn when they travel through on their way to their more northerly breeding grounds. However I have never seen a single one here.

The previous evening (Saturday) not one but two Ospreys were reported nearby at Weir Wood Reservoir just as the sun was setting at 18:30. I was hoping that they would carry on their migration northwards earlier this morning and arrive at Hedgecourt, which is the nearest large waterbody to the reservoir. That is the main reason why I was up nearly at dawn getting ready to wait for one to appear.

Unfortunately I didn’t have any luck with the Ospreys at Hedgecourt although there were some other nice birds about around the lake, with many singing Chiffchaffs, a displaying Sparrowhawk and a male Mandarin which flew in.

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Upon arrival back home I heard news that a couple of nice summer migrants had been seen at Weir Wood Reservoir while I had been at Hedgecourt. These were an Osprey, possibly one of the two there yesterday, and a Little Ringed Plover. Encouraged by this news we decided to head to Weir Wood Reservoir to see if we could see either of these birds ourselves.

Weir Wood Reservoir is quite a large reservoir and the whole reservoir cannot be seen from just one viewpoint. Therefore most people visit both ends of the reservoir, the West end and the Dam end. The West end was where we visited first and where the Ospreys were seen yesterday evening and this morning.

Despite the large number of birders at the car park there were few interesting birds to be seen and certainly no Ospreys. According to one of the birders there, Alastair Gray, they can remain well-hidden during a lot of the day simply perched in the trees beside the reservoir and only become noticeable when they set out to fish most commonly in the early morning and late afternoon. They don’t like to fly a lot unnecessarily as it really upsets the local crows which harass the Ospreys until they land! However there was an immature male Goldeneye amongst a group of Great Crested Grebes which was my first of the year.

After searching for hidden Ospreys unsuccessfully we then moved on to the dam end to look for the Little Ringed Plover. The walk up to the dam wall was alive with the song of many Chiffchaffs and the blossoming Blackthorns were full of life. There were a pair of Pied Wagtails on the grassy bank of the dam and a Grey Heron flew overhead.

After walking along the dam wall for a little while to my relief the Little Ringed Plover came into view. It was small and slender, moreso than its relative the Ringed Plover, and was feeding right on the water’s edge. I was able to get quite close, up to a distance of about 10 feet, and from there I was easily able to observe its distinguishing features. To separate Little Ringed from Ringed Plover, the easiest feature to see is the colour of the bill. Little Ringed Plovers have an entirely dark bill whereas Ringed Plovers have a bill with an orange base and a dark tip. Also,  if you are close enough, you might be able to see the yellow eye ring of a Little Ringed Plover which is a feature absent in Ringed Plovers.

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The Little Ringed Plover

Although Little Ringed Plovers are regular breeders in England and Wales in the modern day, they first bred as recently as 1938. Their expansion across southern Britain is partly due to the creation of man-made habitats perfect for breeding such as water-filled gravel pits. Now over a thousand pairs of these small waders arrive here each spring to leave again in late June/July.

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I am pleased that I have now managed to find my first ‘proper’ summer migrant of 2017. Over the coming weeks, migration is set to pick up as winds become favourable and it becomes warmer. Hopefully I will soon be waking up to the song of Blackcaps and Willow Warblers!

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Ouzels and Sprites

Last weekend was a great one for birding. Saturday started drizzly and it continued like that for the rest of the day, but when I saw news of a Yellow-browed Warbler just 10 minutes away I couldn’t resist going for this scarce vagrant. When we arrived at Bewbush West Playing Fields it was cloudy and miserable. We could tell that this wasn’t the most likely destination for most birders, it was simply a few football pitches, a tiny section of woodland and a hedgerow.

We followed a footpath adjacent to the playing fields, as that was where the Yellow-browed Warbler was seen. Along the whole route I played the call of this species, hoping that the lost bird would call back and reveal its presence. We had no luck for the first fifteen minutes, with only Blue Tits and Robins calling from the trees. However, as we reached a large, dense, berry-laden Hawthorn bush, my mum and I both heard the call. ‘Tseeweest, tseeweest’. That was the bird! I played back the call several times and received a couple more faint responses, but that was it. There was no sign of the bird, it was obviously well hidden inside the dark, dark hedge.

Yellow-browed Warblers are birds that breed in Siberia and winter in South-east Asia, but hundreds each year perform ‘reverse migration’, that is migrating in the wrong direction, and find themselves here in Britain. This is the perfect time of year for these Siberian ‘sprites’ to turn up on our coasts, with a maximum of 600 on one day earlier this year. All records are pretty much confined to the east coast, however, with few making their way inland. This year has so far been a bumper year for them, with 8 being seen in Surrey at the time of writing. Considering that there haven’t been any confirmed records for at least 2 years this is amazing!

The next day the weather was much more favourable and my dad and I made our way to the brilliant Ashdown Forest to see how Autumn was getting on. There had been 12 Ring Ouzels reported during the last two days and these are another species I had yet to see in Britain and indeed the world. When we arrived in the car park we could simply hear autumn calling from the trees: there were Chaffinches everywhere! Given this being a bumper year for beech mast, one of their favourite foods, I wasn’t too surprised to see lots. However, I think 69 is a pretty good total!

Continuing along the tarmac road I heard a distant Pheasant and party of Blackbirds in a dense holly bush. For a moment I thought I could hear a faint ‘chack’ of a Ring Ouzel, but I couldn’t be sure. Further along the road we came to a more open area with gorse and some isolated pines. Ahead of us on the path we could see a flock of about 20 Chaffinches; however they were very flighty and I couldn’t tell if there were any Brambling among them. It didn’t sound like it, no Brambling calls stood out as the flock flew over our heads and into some tall pines at the bottom of a short slope.

A short while later, as we were under the cover of some tall pines and beech trees again, I spotted a flock of thrush-size birds flying around a small Rowan. They weren’t close and even through my binoculars I couldn’t tell if they were Blackbirds or Ring Ouzels; however it seemed unlikely that Blackbirds would form such a large flock. Retracing our steps we managed to find a path that lead down towards the Rowan for us to get a closer look and confirm the identity of those birds. It was a steep but easy descent, in one place we had to move quickly as we came across a huge Wood Ant nest!

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Formica rufa, Southern Wood Ant, nest

The number of birds around us was incredible. A tit flock made their way through the thin birch trees, hanging from the flimsy twigs. It was mainly made up of Long-tailed Tits, however there were also Blue, Coal and Great Tits along with seven Chiffchaffs. Several Redwings passed overhead and there were even more Chaffinches and Goldfinches calling from above.

We soon got to a point where we could see the bush where we had seen the Ring Ouzels feeding. There was clearly a lot of activity on the small Rowan and I was pleased to see, through my binoculars, that they were definitely Ring Ouzels! They were very busy feeding on the ripe red berries, along with many Chaffinches. Three Bramblings were also a nice surprise feeding on the berries, they are my first this winter and always great to see. This year I am trying to attract them in to our garden, but there hasn’t been much luck yet unfortunately.

Ring Ouzels are migrants that breed here in the UK in hilly and mountainous open areas. They don’t usually breed in South-East England so this time of year when they are passing through on their way to their wintering grounds is the best to see them. They are similar in appearance to Blackbirds being primarily black, however the males are easy to tell apart due to the bright white crescent on the breast. All genders and ages have this white crescent however it is duller in the females and especially so in juvenile birds. In cases where the crescent is faint, then the next best method of identification is looking at the wings. In Ring Ouzels, the wing is paler than the rest of the body and almost appears translucent, whereas in Blackbirds they are completely black in the males or uniformly dark brown.

Ring Ouzels are sadly declining in the UK and they have been given the red status. However there isn’t a clear cause of the decline and there are several groups working on researching this species and finding out why populations have decreased so much. However, the least numbers of birds have been recorded after warm summers, suggesting that a lack of food might be the problem. With an ongoing trend of warm weather due to global warming it is likely that the decline will continue.

The Birds, The Bees and The Butterflies

Yesterday I was very lucky to be able to spend a full day at Knepp Estate in Sussex, one of my most favourite sites to visit. We arrived early, at 6am, for some bird ringing to start off the day.

Yesterday we were using a new bird ringing site on the estate, after success at the A Focus on Nature event recently when several Lesser Whitethroats were caught, a bird I have only ringed once before. None were seen let alone caught yesterday, which is very odd. Perhaps they have started to migrate already, however it is still quite early for the Sylvia warblers to be on the move. Maybe they just moved to a new part of the estate.

We did catch many other warblers, however, the bulk of which were Chiffchaffs with 12 caught. One Chiffchaff showed very unusual moult: most of its coverts had just come out of pin. The pin of a feather is where the feather develops before coming out of pin and growing into a full feather. What makes the moult of this Chiffchaff strange is that usually moult is more gradual than the moult this Chiffchaff has shown:

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The highlight of my ringing morning was catching my first Sedge Warbler. This was a very peculiar catch! That is because although there are a number of waterbodies at Knepp, no Sedge Warblers breed here. This individual was a juvenile, which explains it. At this time of year, juveniles are dispersing, leaving the sites where they hatched and grew up. Soon we might even be able to catch adults as they stream south to winter in Africa.

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Soon after the ringing we had to leave to a different area of the estate for a bee field trip which I was very excited about. It was organised by the Amateur Entomologists’ Society (AES). I attended a similar one at Knepp last year which focused on grasshoppers and crickets.

When the field trip got going we were surprised at small numbers of bees that we were finding. Knepp Estate is a great habitat for bees with many different flowers which cater for the different tongue-lengths of bees. For instance, long-tongued bees such as the Garden Bumblebee (Bombus hortorum) are able to feed on Foxgloves and similar plants whereas short-tongued bees like the smaller solitary bees can only feed on flat flowers such as mayweeds and daisies. There are also lots of great nesting habitats for bees, such as fence posts, old lightning-stricken trees and farmyard walls. So why were the bee numbers so low?

The two most likely reasons are due to the weather. On the day it was very cloudy and dull, poor weather for bees to be out and about as they need to warm up in the sun before they can fly. Also, it has been a very poor season as a whole for them. June was a very wet and cold month, severely hindering the opportunities where bees could go out and collect pollen and nectar.

Despite the lack of bees, invertebrates of many other orders were well-represented and we spent time recording and marvelling at those as well between looking for and at bees. One thing that we all noticed were the incredible abundance of Cinnabar moth caterpillars. Their foodplant is Ragwort, and there are thousands and thousands of them at Knepp. In fact, it is the most abundant plant by quite a long way and most plants seemed to have several caterpillars devouring their foliage. Many plants were completely devoured apart from their stem and we found instances where a group of caterpillars had munched their way through one ragwort plant and had moved to another.

When it became particularly cloudy and there were no bees in sight, I became especially interested in finding grasshoppers following the field trip last year. Ralph Hobbs led the event last year and was here again this year and together we found quite a few. We noticed that on the inside side of the ‘thigh’ of the back leg of the Lesser Marsh Grasshoppers we caught there was a dark mark that we also found on Field Grasshoppers. Meadow Grasshoppers are the main confusion species for the Lesser Marsh Grasshopper and they seem to lack the dark mark on the leg. Ralph and I reckon that we have found a new identification feature to separate these two similar species, however more specimens will have to be caught and looked at before we can say that the dark mark is a completely reliable separation feature.

We stopped for lunch at a good site, it seemed. After I had finished my lunch I went exploring in the general area and there were lots of interesting creatures to be found. There were a large number of marsh flies (Dolipechidae) on and by a large muddy puddle, the species is easily recognised by the white tips to the smokey wings. These white tips are especially prominent in the males, which use them to display to the females. It is quite entertaining to watch, especially when a female rejects a male!

Surrounding the lunch site there were many willows (Salix sp.) and some large Oaks. This is great habitat for Purple Emperors, so we kept our eyes peeled.  I had already seen a couple a few weeks ago (blog post here) but I wouldn’t mind seeing another! Amazingly, I didn’t have to wait very long, I was kneeling down looking at a large Toad that had somehow found itself beneath a tight stone when I heard ‘Purple Emperor, just landed! Purple Emperor, just landed!’ coming from down the track. Of course I leapt up and ran towards where the exclamations were coming from. Some of attendees of the field trip were looking confused as our leader, Josh Nelson, tried to point out the magnificent butterfly to them. It was surprising how difficult such a large and impressive butterfly was to spot! The reason was because it was side on to us all, therefore we could only see a sliver of black and white against the oak leaves behind it. I must admit that it did take me a while to find it but once I did I was attempting to show others the butterfly which proved to be a very difficult task, although they all got onto it eventually. There it remained for a while before a ‘Purple Hairstreak’ (definitely not our leader Josh!), flushed it from the oak leaf it was sitting on. We were able to get our best views then however, as it fluttered over the nearby sloe bush and out of sight.

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See if you can spot the Purple Emperor!

So, when everyone was ready we decided to leave the area to see if we could find some bees, although that didn’t really go to plan. We actually only walked approximately 5 metres before we stopped again! This time we heard the calls ‘Purple Hairstreak, landed! Purple Hairstreak, landed!’. Once again, I rushed towards where a group of people were leaning over peering at something on the track. There, on the bare dirt, was a beautiful female Purple Hairstreak, with patches of stunning iridescent purple on the wings. This was easily the best view of a Purple Hairstreak I have ever had. Before I have only seen these small butterflies up at the tops of hedgerows or flying several metres above the ground. So what was this Purple Hairstreak doing on the ground, exposed and with its eyecatching wings open for all to see? It was as if it was saying ‘come eat me, I’m tasty’! Closer inspection revealed that she was indeed pregnant, and appeared to be very weak because of that. After obtaining some quick photographs we managed to get the hairstreak onto someone’s hand and Ralph poured some of his (non-alchoholic!) elderflower cordial onto his fingers. To our delight, the butterfly’s proboscis came out and it started to feed on the cordial! It soon gained energy and we placed it on part of a nearby oak tree which would catch the morning sun and where it would hopefully lay its eggs. Below are some of the photos I managed to take of this beautiful butterfly.

 

Soon we did move on, however, and now that we had our eyes in, we began to spot some more bees and other wildlife. One of the richest habitats of Knepp Estate is the grassland which is peppered with some scrub. On the sandy track through the grassland there is plenty of mayweed, a flower that is similar yet much larger than daisies. There were a few small dark bees, although however much we tried we were unable to catch any to identify them. The track was also riddled with some small circular holes, which were the nests of these small black solitary bees. Eventually, eagle-eyed Josh spotted one on the ground by its nest and swiftly potted it so that he can identify it back home.

The nests in the sandy soil gave us another idea for why there were few bees about. Perhaps the unnatural number of cows, pigs and deer on the estate were constantly trampling on these nests and destroying them. That might be one downside to the rewilding project, although it is restoring habitats to what they were like in prehistoric times, so perhaps bee numbers were this low millenia ago?

Our final stop before heading back to the car park was the outflow of mill pond. The edges of the outflow were rich in aquatic and water-associated flora such as Purple Loosestife, Yellow Loosestrife and Water-plantain. Josh told us that there was a bee that has specialised to exploit Yellow Loosestrife. Unsurprisingly it is called the Yellow Loosestrife Bee (Macropis europae) and it collects the oils from the Yellow Loosestrife flowers to water proof its nest. This allows it to nest in very wet places where other bees are unable to nest. Just as Josh was saying this, Ralph called ‘is this the bee?’. Josh potted it, had a look at it and confirmed that it was the bee! Amazing! This bee is easily identified by its distinctive black and white hind legs.

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Well, there wasn’t a huge number of bees at Knepp that day, although I really enjoyed talking to other naturalists as well as recording other wildlife that I came across. I can’t wait to visit Knepp Estate again!