Friday, 20 October 2017

Where are all the bugs?

Believe it or not, this is a flying insect. So are most beetles.
I think that all of us are aware that there are less "bugs" about than there used to be. Back in the '60s a family trip from Southampton to Yorkshire would require several stops to clean flattened insects from the windscreen of our old Austin. Today we travel much faster and acquire almost no "splats" on the way. That's on our highways, but what about the wilderness, or the nature reserves where we try to create space for insects?

A study of 63 nature reserves in Germany involved trapping flying insects and weighing the biomass caught. Scientists and volunteers have been doing this since 1989, so they have a really good run of data. There was no attempt to identify the species caught, which would be very interesting too, but the numbers speak for themselves.

Over the last 27 years, their average catch has dropped by 76% meaning that they only have about a quarter of their insects left, but are still losing them at 6% a year, assuming that the decline is steady, which it probably isn't. I'm rubbish at maths but it doesn't look like we have very much time to turn this situation around.

Remember that this study was conducted in Germany which is a country that takes the environment very seriously. Despite being part of the same Common Agriculture Policy that we are, their countryside looks to me to be in much better shape than ours. Remember too that this was done on nature reserves, so the landscape as a whole would reflect an even worse situation.

Many of our insects breed in water.
Of course, we want to know what the causes are and what we can do about it. We also want to know if the situation is any different in the UK.

The causes are really not known, but we can make guesses. If the country was a person, the reserves would be its liver. Nature reserves exist to produce a surplus of biodiversity, including insects and plants, that can spread out and (re) colonise the surrounding areas between reserves. We try really hard to do this but, what if the surrounding area is so toxic that they all fail to come home? Many bee species have declined by 30% in recent years and this is directly linked to pesticides on crops like oilseed rape that attract bees from miles around. Pesticides and pollution are certainly involved, but that's not the whole problem.

Imagine that you are an insect that only hatches when conditions are just right. The temperature and humidity are perfect, but your food plant is over, or has not yet flowered.  "That's OK", you say, "I'll just fly upwind until I find my plant, or an alternative." But the (largely wild) plants that our insects evolved to live with (and evolved to live with them) are themselves in trouble. Take a look at a farm near you. How many "weeds" can you see? Those missing common wildflowers once fed our insects and their seeds fed our once-common birds like partridges, sparrows, buntings and finches. And that's farmland. Maybe the neighbourhood is now a new town with concrete parking bays, astro-turf yards and densely packed "town houses" with neither parking or gardens. It's impossible to argue that these changes haven't happened in the last 27 years, isn't it?

But here's another factor; climate change. If we just stay on our nature reserve where, on the surface, things haven't altered that much, we can see some pretty amazing changes such as very early springs and winters with no frost. Rivers no longer regularly flood in winter and lakes no longer freeze. Flowering dates may be all out of sync with the emergence of insects. And what about all the new species that are arriving? Many of them are predators like Asian hornets and harlequin ladybirds. There are new parasites too but these newcomers are a minor factor in my view.

The survey looked only at flying insects, many of which have their larval stage in water. We tend to think of a river or lake being a pretty stable environment, separate from the land around it, but of course it isn't. We have had acid rain, over abstraction, siltation, and eutrophication. If the main cause was to be pesticides, they would surely be in our waterways too, and where do we think all those medicines and chemicals go that we tip down the drain or the loo? A lot of upland rivers have never really recovered from pesticides used in sheep dips years ago and drainage of the uplands has created a rapid run-off situation which results in multiple short spates with droughts in between.

Paxton Pits Nature Reserve. Looking good on the surface.
The average temperature in our ponds has risen, and this can have a huge effect on the sensitive creatures that live there. Warm water dissolves less oxygen and has more algal blooms. It can become like a thick soup in summer with floating mats that prevent the sunlight from reaching the bottom, killing off the underwater plants. As it's biodiversity declines, the pond loses its ability to recover from shocks like these.

Studies have been carried out over the years on many of our waterways and lakes to see changes in in the insect species that live there. Anglers have had concerns about this all of my lifetime ass the hatch of mayflies has all but disappeared in many rivers. I used to use a trout fly called the March Brown but the early season fly that it imitated is no longer around.  Lakes and Lochs that once boasted prolific hatches of mayflies and caddisflies now only contain silt-loving midges that emerge in smothering swarms on summer evenings. Now it seems that even they are declining.

Red Admiral Butterfly
Does the German study reflect our situation in the UK? The numbers may not be exactly the same but my bet is that they would be really close. One indicator is the decline in butterflies which are monitored every year by the charity Butterfly Conservation. 2016 was the worst year on record with 40 of the 57 species monitored in decline. Interestingly, some species have increased their ranges, probably because of climate change.

Moths are also in trouble. "Studies have found the overall number of moths has decreased by 28% since 1968. The situation is particularly bad in southern Britain, where moth numbers are down by 40%. Many individual species have declined dramatically in recent decades and over 60 became extinct in the 20th century." (Butterfly Conservation website)

I have worked on Nature Reserves for over 30 years and I studied butterflies and moths on Salisbury Plain in the 70s. I can tell you that insect decline is real and has arrived at a nature reserve near you.

The story get's worse. It's not only insects that are declining, on and off our reserves, insect eating birds are in trouble too. Shortage of insects in the breeding season means that chicks starve in the nest. The adults may only have a couple of years to reproduce themselves in and every failure contributes to a fall in the population. Is this what happened to our Nightingales?  Swallows are declining across Europe, but seem to be stabilised in the UK. They are helped by having a long breeding season and may attempt to raise three or even four broods in a year, whereas many warblers only have one brood. Overall, our bird population is down 6% since 1970, but some species fare much worse than others.

This is from a Defra report this year (2017): "Birds associated with farmland, which covers 75 per cent of land in the UK, were down by 55 per cent, woodland birds by 21 per cent and seabirds by 20 per cent."

What can we do about all this? Certainly we must clean up our act and think Bug! When we manage a reserve, a farm or even a garden, we need to think about increasing the number of insects.



Thursday, 5 October 2017

Graveyard

Yew berries.
Every  autumn, when there is a sunny day with a deep blue sky, I head to the churchyard to see what's about. As I get older, I feel a growing affinity for this time of year, but not in any negative way. After the fading brilliance of the summer, I look forward to the crisp, slanting light and glowing colours.

Despite the sun and the blue sky, today is a very windy day, due to the remains of two Caribbean hurricanes that are passing through the UK, bringing a fall of American birds to our west coast and our most far-flung Atlantic islands. There is a cinematic blizzard of golden and brown leaves between the headstones that could denote the passage of time but, because of the strong wind, my chances of catching any small birds out in the open are limited.

A headstone spattered with fallen berries.
I work my way along the south wall, keeping my back to the sun so that the scene is well illuminated, but all I can detect is a small disturbance in a yew tree that has a holly bush growing up through it. A pair of great tits are snatching bright red arils; the scarlet berries of yew trees that are edible, but extremely sticky.

Blue tits hunt spiders in a cedar nearby and a pair of extremely shy blackbirds cluck in the undergrowth. They explode skywards as I approach and I wonder if these are the first winter visitors to the church-yard. After all, unlike their wilder Scandinavian brethren, English blackbirds are not generally bothered by my presence. Two song thrushes flit from a hawthorn bush: definitely song thrushes, redwings are darker in hue and it's too soon for them to be here.
Shaggy parasols, ignored in the churchyard
but very much edible. 
At the back of my mind, I'm hoping for a few early migrants from the east, but the wind has been in the wrong direction. A few goldcrests and yellow-browed warblers have reached the Norfolk Coast, but the main inward migration hasn't started here yet.

In fact, the last swallows and martins are still saying their farewells and the neighbouring wetlands along the Great Ouse valley are still rich in insects such as dragonflies that attract the last few hobby-falcons of the season.

In my graveyard, I watch the last of the summer's butterflies sunning themselves on an ancient sun-bathed wall. A fresh-looking red admiral and a faded and battered speckled wood are attracted to the tendrils of flowering ivy that cling to a memorial stone. They need to keep sharp because predatory hornets are patrolling the sunny glades. Under a faded buddleia, I find a pile of butterfly wings that the hornets have discarded. 

All the conkers on the village green are gone,
but children shun the graveyard. 
It's a rich habitat, this graveyard, with sunny walls, evergreens, deciduous trees and lawns. Ladybirds cling to tombstones. squirrels gather nuts and acorns while robins hunt for worms on freshly dug graves.

In autumn, it's a place ripe with metaphors for death and decay but that's not what I see. It's an ancient man-made woodland habitat that holds it own special mix of residents and attracts a good range of migrants, and that's ignoring the church itself with its hibernating bats.

Etched letters in stone
The yews were planted long ago to provide longbows for our wars with the French. The cedars, pines  and redwoods are Victorian imports from the new world, while the other trees such as holly, alder and elder were brought in more recently by birds. Horse chestnuts and ash trees were planted quite recently, simply to provide diversity, but the oaks were probably planted by squirrels or jays, maybe a hundred year ago.

The great thing about churchyards is that they give you perspective; a long term view. It's not just all those graves with their headstones dating back through the centuries, even though they are so interesting in themselves. Have you ever noticed how few and how localised the names on the stones were only a hundred years ago?

Gargoyle. What animal is this?
Can we re-introduce them?
Graveyards measure time for us. As more bodies are buried, the ground actually rises, so that the church may appear to sink, and, because the stones are dated, we can measure the rate of growth in lichens or the rate of decay in the inscriptions due to air pollution. The graves record wars, plagues and waves of immigration, the infant mortality rate and our own growing longevity.

But all  of this twaddle can be set aside if you like.

The fact remains that graveyards are just great places to see wildlife and to grab a bit of peace, especially in an urban setting.  Visit yours and tell me what you see.


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Sunday, 3 September 2017

Every year is different......

Common darters by Petter Hagger
Have you noticed that every year is different? My computer tracks all my photos by date so I can see what the place looked like at the same time each year. In dry summers the trees and grasses look burned off by August yet this year they are still lush and green. The horrible spring weather had its benefits after all; at least it did for the flowers and the butterflies. For the birds, the results were more mixed.

Some birds only raise one brood of chicks a year and so, if they nest too early, or too late, or are just unlucky with the weather, it’s a catastrophe. The blue tits in our camera nest box failed to brood the eggs properly, presumably because one parent died. It was a late spring, causing many migrants to arrive late and in smaller numbers than usual. This was a terrible year for nightingales, with just a handful of singing males arriving here, and they didn’t all find mates. Only one pair of turtle doves showed up. As Donald Trump would say, “Sad”. Im really worried for the future of these particular birds as, if they produced no young this year, we might not get them back at all. Until recently we bucked the trend and held on to our nightingales while the Uk population as a whole steadily declined. So much for complacency.
Wild flowers in Peter's Field

However, those birds that nested later or have made repeated attempts produced quite a few chicks. We have two pairs of nesting barn owls this year (plus one in the quarry) and our buzzards nested again. For butterflies and dragonflies, this was a brilliant year and the wildflowers still look good in September.

We have had a few interesting migrants in recent weeks including a wheatear, an osprey, sandwich terns, ravens and hobbies, but my star bird was the great white egret that stayed and stayed. Now the first winter wildfowl are arriving from Iceland. Watch the numbers of widgeon, teal and shovelers build up over the coming weeks.  

Rose hips
This autumn, I forecast a bumper crop of berries and fungi and, because our water levels are low, perhaps some interesting waders to watch.

If you want to keep up with the changing seasons, why not join Martin Runchman on his Third Thursday Walk each month?



Wednesday, 30 August 2017

Quarry Extension News.


Paxton Pits Nature Reserve.

The new sorting plant.
In August, planning permission expired for the 2002 extension plan that was delayed due to the recession when the site was closed. Now the quarry is up and working again so Aggregate Industries has  submitted a revised proposal to the County Council  that will take them up to 2029. Here are the basic points as I see them:

·         Much of the land in the scheme belongs to Oxford University, the rest belongs to the estate at Diddington.

·         The plan is very similar to the original one, by which Heronry North Lake, Island Pit, Pumphouse East Pit and Diddington Pit will become part of the nature reserve.  

·         The current excavation between the A1 and Boughton Lodge is expected to continue for 5 years. The arable fields to the west of the processing plant will be dug out over the subsequent two years to create large reed beds.

·         There is a period of landscaping and after care that will continue after extraction has ceased, hence the 12 year plan.

·         There are some amendments to the original plan. The biggest one is that Diddington Pit is to stay as one lake that will not be divided by a bund. The entire lake will come into the Reserve. A couple of short sections of path and cycle way have been slightly diverted around Diddington and the extent of reedbed creation has been slightly cut.

·         As part of a revised plan for the process of extraction, the company has asked to use modern diesel pumps, not electric ones, as they are more mobile. Each pump sits in a tray that catches any leaking oil.

·         Material is currently brought to the plant by conveyor but Aggregate Industries have asked to transport quantities in bulk within the site by lorry.
The Parish Council and the Friends have been consulted about the proposal. Of course the Rangers are really pleased to see our dream of a bigger reserve with more access for the public  draw nearer to being a  reality. Our main concern is to get access to the extension a bit at a time, rather than having to wait until all of the quarrying is over. 2029 is a long time away and we can’t see why the lakes that are away from the quarrying process shouldn’t be handed over now so that we can put in paths, signage and hides. The Friends of Paxton Pits Nature Reserve feel the same and this point has been supported by Natural England.

This is an extract from a statement by Aggregate Industries:

"The Company is proud to say the site reopened during 2016 and we are committed to completing mineral extraction which will help achieve the full aims of the restoration scheme. 
The quarry has three remaining extraction areas B, C and D which will be worked over the next 7 years. The remaining restoration includes agriculture along the western boundary, wetland / reedbeds adjacent to the sailing lakes, conservation grassland and woodland which in part will be incorporated into Paxton Pit Reserve.  The restoration scheme also sees improved footpath, cycle ways and bridleways." 

Mike Thomas, who is the chair of the Friends of Paxton Pits sums it all up by saying:

"The extension to the Nature Reserve would not only bring significant benefit to the wildlife in the area but would also expand what is now a valuable local resource to a significant countryside recreation area in south west Cambridgeshire."

 
Map showing restoration proposals.
Access map.

Friday, 25 August 2017

A group visit.


Wheatear


I went into work today to lead a small group from Market Deeping U3A (University of the Third Age.) Nine of them turned out and I enjoyed their visit so much I stayed an extra hour. We saw so much! 
Hobby
If birds are your thing, then a wheatear in the former Lafarge site should float your boat. Then we picked up a lesser whitethroat but lost it while we were distracted by a hobby. There was a kingfisher and a buzzard at the river viewpoint, plus all the usual birds on the Heronry Lakes. 
Brown argus.
For me the wasp spider, brown argus, small heath and common blue butterflies were a delight and the plants were excellent too. We poked around and found cornflower, corn chamomile, poppy and wild carrot as well as my set pieces like great dodder and blue fleabane, which is everywhere at Paxton. We found yellow-wort (a gentian related to centaury) in an area we didnt expect it. It usually grows on chalk.
Mating damsels.

And finally there were dragonflies and damsels. We all saw migrant hawkers, southern hawkers, brown hawkers and ruddy darters. 

Wasp spider
Don't ever tell me there's nothing to see at Paxton in August!

If you would like to bring a group for a guided tour, please book well in advance. You will find a booking form on our website at https://sites.google.com/site/paxtonpitsnaturereserve/visiting/group-visits

Sunday, 2 July 2017

Bullying butterflies.

Hunting for butterflies sounds like a bit of a joke. You might imagine and old clergyman out with a net and a killing jar, or a man wearing shorts like a boy scout, but with a beard and thick spectacles, waist deep in meadow grasses. In fact, butterfly collecting is still big business. I remember going to a forest on top of the Uluguru mountains in Tanzania to find quite a sophisticated trapping operation in progress, and this happens across the tropics. The collectors who buy these butterflies are mostly in wealthy countries like ours and the victims end up in glass cases.
Ringlet

Needless to say, when I go butterfly hunting it is with a camera, not a net and it is quite a challenging sport. Having said that there is the lazy way, which is to find a thistle flower, some lavender flowers or a buddleia bush and just wait. If it's not too windy and there are butterflies about they will come to you. I've had great success with this method but mostly with the big common  garden butterflies such as tortoiseshells, red admirals, peacocks and brimstones. The rarer butterflies tend to be a bit more picky about where to live and which plants to visit.

Comma
In a flower-rich meadow you would expect butterflies to flit from flower to flower like bees do, but there's much more going on than that. A solo migratory butterfly, such as a clouded yellow, never seems to stop flying. They may just be migrating through or they may be looking for a mate, neither of which involves landing on a flower.  Other species don't travel far at all, but they still don't spend all day feeding. These butterflies are quite territorial and so, although they might start the day sunning themselves to warm up, they need to find a spot to show off and attract a mate, just like birds do, except that butterflies don't sing (at least I've never heard one.) They need to perform a dance, and perhaps use an attractive perfume too.

Along a shaded path there might be dappled sunlight. Each golden-green sunny glade is a stage for a street- performing woodland butterfly who will breakdance himself dizzy to attract a mate. He will defend his pitch against other butterflies and even other insects such as bees and hover-flies.

Green-veined white
You and I might think that one bit of a meadow is much like any other, but butterflies don't see the world in the way that we do. The flowers in the meadow glow for them like starbursts and a flowery patch is to be desired and fought over. Yes, butterflies are selfish, stroppy, competitive, bullying and aggressive!

This week I was the old man in shorts who was wading through the long grasses of our Great Meadow. I had gone there with pupils from Spring Common Academy to read the meter on our water pump but was soon distracted by the thousands of butterflies we saw there. Not for the first time, I was frustrated in my attempts to get a sharp photograph of a butterfly because there was always a blade of grass in the way, or the insect moved. I soon realised that, every time a meadow brown or a ringlet landed, it got bumped off its perch by another butterfly.
Small skipper

It seemed to me that the small blues and skippers were not so competitive, but there were fewer of these and more flowers to go around.

The butterflies I was chasing were mostly engaged in mating and territorial behaviour so they didn't stay still for long. Later they would move on to laying eggs on the food plants that their caterpillars need, just a few eggs here and there, not stopping for long at all.

Marbled white with hitch-hiking fly.
When it comes to feeding, some plants are much more attractive than others, but butterflies are also attracted by smell. Purple emperors patrol the woodland rides at Fermyn Woods and come down to feed on......(you wont like this) ....horse droppings and urine. Many butterflies are attracted by spilled beer of fruit juice. They even gather on the corpses of dead animals and lick away at the gooey moisture they find.

My star find this week was a single marbled white butterfly, which did eventually settle. When I photographed it, I found that it had a fly sitting on it. I guess photo-bombing is another reason not to hang about.

You can listen to a podcast about butterflies at Paxton Pits at www.whatcomesnaturally.podbean.com 

Friday, 5 May 2017

Willow chiff??

Today I bumped into a chap called Tony Fulford from the zoology department at Cambridge. He had got wind of the fact that we have a lot of willow warblers and chiffchaffs at Paxton Pits, and they don't all sing from the same hymn-sheet! Working here and in the Gambia, he has discovered that willow warblers react to chiffchaff calls by repeating them. Basically, they are bilingual. So are they hybrids? It doesnt look like it to me, but the two species are very similar.

Chiffchaffs sing from tall trees while willow warblers use lower bushes, but both nest on the ground and look very similar. Our willow warblers generally winter in West Africa while chiff chaffs winter around the Mediterranean, but they overlap in all respects. We tell them apart by leg colour, wing length and of course, song. But it's not that simple.

As part of his study, he has ringed one of our birds and measured it up. It's pure willow warbler but it's bilingual.

"Attached are photos of the wiffwaff. Note the emargination to the 5th primary. The 2nd primary was noted to be approximately as long as the 6th. So typical WILWA wing. The wing chord was 68mm and weight 9.4g - typical for male WILWA but way off for a CHIFF. Curiously the bill has a slight hooked overgrowth."
"This was a rather tentative bird compared with some I've encountered. As usual in response to both WILWA and CHIFF playback it stop singing while it searched for the source but once the playback had stopped it resumed with a rather quiet chiff-chaffing. After a minute or two it was back in full swing with its usual half-half song."
Ypu can hear our willow warbler here:
https://paxtonpits.podbean.com/e/willow-warbler-at-paxton-pits/
His new ring number is EJE 495.