It’s Popping Hot

Some people find plants boring. However, they are very clever. How can a plant be clever? Through evolution, plants have developed many fascinating ways to survive and thrive.

The key to a plant’s success is largely in the seed dispersal technique. Without a way to disperse seeds, plants would not be able to colonise new suitable habitat and spread. Therefore plants have learnt to be ingenious in their methods of ensuring the future of generations to come.

Yesterday afternoon I was walking through my local farm when I heard a few pops coming from the vegetation beside the path. At first I thought they were the calls of a grasshopper or a cricket, but definitely not a species I had heard before. I stopped and waited to see if I could hear anymore. I did, and this time I thought they sounded like click beetles, but why would so many be clicking at the same time? I was puzzled by this strange sound until, accompanied by a pop, I saw a quick movement out of the corner of my eye. I looked closer to where the movement had come from but I couldn’t see anything that I thought could have made the sound, just a patch of vetch. Then I realised that the sound was coming from the vetch itself!

Vetches are plants related to peas, they have pods like peas although usually much smaller. The pods begin green, the same colour as the leaves, and then as they mature they turn darker until they are brown. Plants in the pea family often have pods that pop, which is advantageous to the plant as it is a great method of seed dispersal. This method ensures the seed is enough distance away from the parent plant to prevent overcrowding.

Before I witnessed the popping of the seed pods yesterday I had no idea how it actually worked. How did the pods pop? I have done a bit of research and what I found out was fascinating. On hot days like yesterday the seed pods dry out, aided by the dark colour of the mature pods in some species which absorb heat. During the drying process forces build up inside the pod until it reaches a point when the pod explodes. In most pods there are two lines of weakness running along the pod, and it is here where the tensions which are set up in the wall of the pod cause the pod to explode. Similar to when a pulled spring is let back, the two halves of the pod curl back at lightning speed which flicks the seeds out of the pod!

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These two pods are still green and have not dried enough to pop.

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Two seed pods which are ready to pop! They have dried in the hot weather and turned brown.

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Two freshly-popped seed pods, showing the two halves of the pod

 

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Golden Robber

Diptera, the true flies, are not one of the most glamorous groups I must admit. However, they are one of my favourites because of the sheer diversity of shapes, sizes and colours. I recently added my 100th fly species to my Pan-species List, a figure I have been working towards for quite a while now. The fly species that I am writing about today was my 103rd.

Yesterday I went on another Hedgecourt Invertebrate Survey trip to try to add more species to my list. There was lots about and only about 10 metres into the reserve I was distracted by the many invertebrates I was recording. These included a White-legged Damselfly and a snipefly (Rhagio tringarius) that voluntarily flew into my net. I was so distracted that at first I didn’t notice a medium sized black fly that had landed on my hand. Annoyingly it was on my right hand, my camera hand, so I found it difficult to take a photo. Then I realised that it was strangely placid, and I coaxed it onto my left hand where I was able to photograph it.

The fly had its wings folded back, which made it look like a Bibio. However, when I blew the wings apart and off from the abdomen it clearly wasn’t a Bibio. It had a long abdomen with a ring of golden hairs between each tergite (segment). To identify it I posted the photo on the identification forum on the Dipterists Forum website. The Dipterists Forum is a society set up for the study of flies. The Dipterists Forum run regular field meetings, such as the current one in Canterbury, curate Diptera-related Wiki pages and a whole host of online forums and run recording schemes for different fly groups. I received an identification for my fly very quickly: it was the Golden-haired Robberfly.

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Before I saw this one, I hadn’t seen a robberfly for a surprisingly long time although they are very interesting insects. They belong to the family Asilidae, with about 5000 species worldwide. The alternative name ‘assassin fly’ is very appropriate as they are very effective hunters that tackle difficult prey like wasps and occasionally even dragonflies. They are very fast flying, allowing them to outpace most of their prey. They are also patient, sitting on a sunny plant or log waiting for suitable prey to fly past. Even robberfly larvae are formidable predators, feeding on other insect larvae and eggs beneath the soil.

This robberfly wasn’t the only interesting invertebrate I found on my survey trip. I also found two caterpillars that I have been wanting to see for a long time: Mullein Moth caterpillars. They are very impressive and, as the name suggests, they usually feed on Mullein. However, some other plants are sometimes also fed on. I found mine in a habitat I really wouldn’t expect to see them in. I have never seen Mullein growing in Hedgecourt at all… let alone a wet reedbed! Still, there they were, a pair of them. They were large, well grown, and stunningly coloured.

If they weren’t feeding on Mullein, then what were they feeding on? Water Figwort has been recorded at Hedgecourt, and is apparently a known foodplant. Unfortunately at the time I didn’t note down what they were feeding on but I will look to see if there is any Water Figwort where the caterpillars were feeding the next time I visit.

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A Quick Walk down Mill Lane

 

This morning I walked along Mill Lane which runs along the east side of Hedgecourt Lake. What struck me first was the height that the Water Dock had grown to compared to the last time I visited the lake. It was at least the height of me if not taller. This is not unusual though, some plants can grow to more than 2 metres. This plant can grow in very tough conditions, these ones grow on the concrete wall of the lake against the hard wind and the severe waves that sometimes form. Equally large were the leaf mines that covered almost half of each leaf. Some leaf-mined leaves were about 75 centimetres long, so the leaf mines were huge! Whose larvae are growing up inside those leaf mines?

To identify the culprit, I visited a site I use regularly: http://www.ukflymines.co.uk
I went to the Rumex (Dock) section of the site and I saw that luckily there are not that many leaf mines on Dock in Britain. From the photos on that page I think that my species is Pegomya solennis. Pegomya solennis is a species of fly, unfortunately not new for my list although very impressive. This species is not a large fly, but the key to its very big mines lies in teamwork. In each mine there are two or more larvae that at first work together making a wide corridor. They then separate and each form a large blotch which all fuse together making one large blotch from which they feed. Sometimes the blotch size is increased even further when the blotch joins the blotch from a different leaf mine.

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The larvae feed on the leaf from inside these blotches.

Along the grassy verge between the lane and the lake there are several large patches of Bird’s-foot Trefoil, Ribwort Plantain and Black Medick. I thought these large patches might hold some specialist species but alas not much was swept from them using my net. The only species of interest was a single Platycheirus peltatus, a species of hoverfly and my 94th fly species on my Pan-species List.

Moving on, it was still windy and not too warm so most of the wildlife was hiding away. I stepped down onto one of the fishing jetties to get a closer view of the lake wall without the risk of falling in to the nippy water. On top of the concrete wall was a hole, which was occupied…

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The white spherical object in the centre of the hole is an egg sac, which belongs to a very large spider. I tried to coax it out from the hole, but it wouldn’t come. I’m not certain what it is, but one possibility is the mouse spider, Scotophaeus blackwalli. However it is usually found in sheltered places indoors so I’m not sure what it is doing on this exposed wall if I am correct.

On some more Water Dock further along I noticed a colony of aphids. It is often not hard to identify aphids when you see a colony on a particular species of plant. For this one I just searched with Google ‘aphids on dock’ and I was presented with two options: Aphis rumicis and Aphis fabae. Aphis rumicis is more plant-specific, being found on mainly dock and sometimes on rhubarb. Aphis fabae (the Black Bean Aphid), is much less so being found on a wide range of vegetables. Unfortunately the two are quite similar, although I am leaning towards A. fabae due to the paler legs shown in many of the photos I have seen on this species. My 50th hemipteroid (bug) for my Pan-species List! In my (not great) photo, the colony appears to be being attended by a Lasius ant.

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Suddenly the sun emerged from behind the clouds and everything seemed to suddenly wake up. There were loads of umbellifers on the lake shore which were great for invertebrates although I had little time to examine them closely. What I did find, however, is a mini-miner. These are very tiny bees in the genus Andrena, which I don’t come across too often. Their larger relatives in the same genus I more often come across. There are 10 mini-miner species compared to 57 other Andrena species, although I find them much harder to identify. Also, many of them have very restricted distributions.

I potted this tiny bee and when I arrived back home I took a few hasty shots though the gap between the lid and the pot. The long, very white hair caught my eye and helped me when I attempted to identify it using Steven Falk’s Field Guide to the Bees of Great Britain and Ireland. Currently I think the most likely species is Andrena niveata, the Long-fringed Mini-miner. Modern records are restricted to South-east England and it is not very common, therefore I am tentative with my identification and I will hopefully get it checked under the microscope or with an expert. In the book it says: ‘the body hairs are much whiter than in other mini-miners…the overall effect is thus of a very silvery, strongly marked mini-miner’. This definitely fits my bee.

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I was very pleased with the number of interesting and new species that I found this morning, given the short amount of time and the unfavourable weather conditions. I can’t wait until the summer holidays when there will be more time to explore!

Some interesting Blackbird behaviour

There has been some drama happening with our Blackbirds this year. Before exactly a month ago, we had a regular pair of Blackbirds that inhabited our garden and regularly visited the space under our feeders. We could tell this pair from the other Blackbirds as both were ringed earlier in the year. They had built a nest in the middle of March, which had 3 eggs in by the time I left on holiday to South Africa. When I returned the eggs should have been at the nestling stage, but the nest was empty.

On the 1st of May I noticed 4 male Blackbirds chasing each other around the garden pursued by a female. They disappeared out of view until a few hours later I spotted a male singing in the tallest Oak that I can see from my bedroom window, which leans over into our garden from our neighbour’s. It wasn’t ringed.

A few days later something I wasn’t expecting appeared below our feeders. A juvenile Blackbird. There was still no sign of the original pair, so this one must have been brought in by the currently dominant pair. But why only one? I think that as this is still quite early in the year, the parents might not have been able to find enough food for all 3 or 4 of their chicks, especially considering the strange weather we have been having. I will keep watching the Blackbirds to see if the ringed pair re-appear.

From what I have researched about Blackbird territories, I think that my garden must be quite a good habitat for them. The RSPB say that they are solitary birds, but “Small feeding and roosting aggregation sometimes form at good sites”. We have around six Blackbirds in our garden throughout the year and more in the winter when migrants from the mainland come in. There currently seem to be 3 pairs and therefore 3 territories in our garden, one in the front garden, one in the front half of our back garden and one at the back of our back garden. The size of these territories seems quite small for Blackbirds, so there must be good concentration of food. Inevitably, there have been squabbles from time to time.

I will continue to watch these Blackbirds. Who knows what interesting behaviour I could see next or will I locate the ringed pair?

 

 

 

 

The spider on my wheelbarrow

When I was five or six, I used to play with a small green and yellow wheelbarrow, ‘helping’ my dad transport sticks to the compost heap. It has been sitting outside the garage on a bit of patio since then, contributing nothing except a few algae species that have accumulated at the bottom. However, on Sunday, I had a big surprise.

On Sunday I went out for a complete circuit of my garden and my first stop was the dry bit of patio where the wheelbarrow was. Except for the Tree Bumblebee nest in the wall and the Procumbent Pearlwort growing out of a crack, there wasn’t much else. That was until I bent down to look at a small spider running across the patio – Salticus scenicus. Not a new species for me nor anything rare but the first for me in the garden this year.

Turning around to get up I noticed another spider, even smaller, running intermittently along the yellow handle of the wheelbarrow. I got up and moved into a better position to see the spider and it paused, allowing me to get a few quick photos. I was doubting the fact that it could be identified so I didn’t try until that evening, when I put it on iSpot. Soon enough, to my surprise, I had an identification!

Steve Gregory, one of the invertebrate experts on iSpot had added an identification to my observation: Bianor aurocinctus. He wasn’t certain as it was quite a rare species, he said, although he added in the comments section that he didn’t think there were any similar species. Looking on the NBN Gateway I think he is right that it is quite rare. The Gateway doesn’t hold all the records but the Bianor aurocinctus records on it at the moment are mostly along the River Thames with a few scattered records in central England and east Wales.

The most striking and distinctive feature of this spider are its swollen, hairy front legs. I’m not too certain about the purpose of these legs, but I am assuming that they are used in attracting a mate. They are definitely useful in identification though! Despite being so rare, this spider doesn’t show much of a habitat preference. All it needs is a dry area, so our patio is perfect. However, it is more often found on short vegetation, which there is none of on our patio, in sand and chalk quarries. Sites such as Portland Bill are perfect for it. It has only been recorded in 38 hectads (10km x 10km squares) since 1992 and is Na (Nationally scarce A).

I’m excited to find out what other rare species are hiding in the unlikely corners of my garden over the coming summer…

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Hedgecourt Invertebrate Survey: Part 1

I am very lucky to live within walking distance of a great Surrey Wildlife Trust reserve in South Surrey near the Surrey-Sussex border. Hedgecourt Nature Reserve is quite a small reserve, but it contains a mix of habitats. It is situated on the edge of Hedgecourt Lake, so that you can get a good view of the open water and the river that feeds into it runs through the nature reserve, creating a few stony streams too. There is a lot of marshland on the reserve, some open and some with tree cover. The woodland near to the lake is almost always flooded, especially so after rain when the lake level rises. This creates a fantastic habitat and I keep saying that it resembles the Florida Everglades in some places. I keep expecting to see a snapping turtle rise up from the murky water! There is also lots of dry woodland – interspersed with many small ponds – which attracts birds such as Nightingales.

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It is usually much wetter than this!

This year I have been given permission to conduct a relaxed invertebrate survey of the reserve. The wardens were very happy to have a free survey take place, they haven’t had one in quite a few years. My target number of species is 1000 by the end of the year but I’ll have to work quite hard to get to that figure! On my Pan-species list I barely have 1300 species, and that includes fungi, birds, mammals and plants!

So far this year I have made a few visits, mainly mopping up the common species before I get weighed down by the bizarre beetles and fantastic flies! Most were in the first winter period (January – March).

However, I have made one April visit so far this year. The walk through the reserve started off well. I had just passed the entrance sign when two Brimstone butterflies flew past across the marsh. A Buff-tailed Bumblebee clumsily flew in front of me and a Peacock butterfly erupted from the path ahead. There is a patch of new iris shoots coming out in the first marsh and I noticed small dark things on them when I walked past. At first I thought they were just holes in the leaves but on closer inspection I saw they were very small beetles. I tried to get one in the pot but it vanished – characteristic of a flea-beetle. One moment it’s there, the next: Whoosh!

When I got home I searched ‘flea beetle on iris’ on Google. Lots of results came up, almost all resembling my beetle. Guess what it was called? The Iris Flea-beetle (Aphthona nonstriata)!

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This mating pair was more reluctant to hop away.

Just 10 metres further up the path the open marsh turned into the woodland marsh. I bent down to have a look at a large ground beetle that was scuttling across the path when another one, smaller, caught my eye. A third species, which I recognised as one I found the other day: Asaphidion flavipes, also ran out from under a clump of moss. This site is great for beetles, I thought! I ran through the first two beetles at home and the first I didn’t find too hard to identify. It was quite distinctive and it turned out to be Elaphrus cupreus. I’m glad we found this species as it is found in very wet habitats so the wooded marshland at Hedgecourt is perfect for it.

The second one was a bit trickier as it was small and there weren’t really any distinctive markings. I spent a quite a while puzzling over this beetle with The Carabidae (Ground beetles) of Britain and Ireland (Luff, 2007) open on my lap. Eventually, using a combination of appendage colour and pronotum shape, I narrowed it down to Bembidion properans. This is interesting as this species is usually found in drier areas, the complete opposite of this section of the path at Hedgecourt.

My favourite part of the reserve is along the river that runs into the lake. The vegetation has recently been cut beside the river, presumably to let new vegetation grow through. The sun was shining directly on this open patch and there was lots of insect activity. Some Lady’s Smock (Cardamine pratensis) was already poking through and on one flower I only just spotted a resting Orange-Tip Butterfly. My first of the year!

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There were also lots of flies taking advantage of the warm weather. Three hoverflies were noted – the very common Eristalis pertinax and Helophilus pendulus and the very-common-but-new-to-me Platycheirus albimanus (White-footed Hoverfly). I also saw a Bee-Fly hovering above the cut vegetation, I have seen many this year.

A bit further along the path, I walked out onto the boardwalk to see what was out on the open water of the lake. I was glad to see three Common Terns loafing about on the buoys, showing no interest in breeding. Maybe they had just arrived and were catching their breath! They were sadly the only migrants I saw besides 3 male Blackcaps and a Chiffchaff.

We walked back along the path and turned onto the boardwalk leading into the sheltered reedbed. I was hoping to see an early Reed Warbler, but I did see another Peacock and a Comma butterfly on the boardwalk. They were absorbing up the sun before it goes away again!

There are several old trees by the edge of the lake where the bark is peeling off. I looked under one of these pieces of bark and I found both Common Shiny and Common Striped Woodlouse. I haven’t really looked at Woodlice in great detail before so the Common Striped was a new species to me. It is good to get them both on the year list as I’ll certainly be more busy in the warmer months.

So, I’m currently on 42 species for the year. Only 958 left to go before I reach my target! Hopefully I can find some of Hedgecourt’s specialities before the year ends.

 

More Redpoll News!

The Redpoll numbers in our garden have been stable during the past month, if not increasing. On the 12th, Tony Davis came back to our garden to do some more bird ringing and I was really excited to catch the Redpolls that have been visiting the nyger feeder.

Tony set up the Redpoll tape on the speakers, in order to attract them to the net. The session was slow to begin with, but soon enough we had five Redpolls in the net in one go! It was really great ringing what I think is now my favourite bird and we even ringed another orange-capped individual, sadly definitely a Lesser Redpoll this time rather than a Mealy!

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The next Redpoll was just a bit more exciting! It was caught on its own in the net and when Tony said that it already had a ring on, I wasn’t that happy. However, I had rushed to conclusions! All of the Redpoll-sized rings I have used with Tony start with a ‘T’ followed by the numbers, but this one started with a ‘Y’, which meant it hadn’t been ringed by us!

A number of exciting possibilities went through my head. Maybe it was ringed in Russia? Or Estonia? Unfortunately it had the details of the London Natural History Museum on it which means that it was ringed in the UK.

To get the details of where the bird was ringed originally, Tony had to submit the data to the BTO, who would send back the details. It took just over a week to receive the results, which were very interesting!

The bird was originally ringed at Allerthorpe Common, East Riding of Yorkshire, 312 km away from here in Domewood, on the Sussex-Surrey border! Also, it was ringed with the age code ‘3’ on the 24th November 2011! This means that it hatched in the 2011 breeding season as the code ‘3’ means that it hatched during the calendar year it was ringed in.

To sum up, the Lesser Redpoll ‘Y562211’ was ringed 312km away from Domewood, 1580 days before we caught it and it is coming up to its fifth birthday! Lesser Redpolls usually only live to about 2 years old and the maximum recorded age is 6 years, so hopefully we catch this bird again next year!