30 Days Wild – Day 9

The moth trap at Blashford was run last night, in fact we run it almost every night and have done so for many years. The advantage of doing survey over long periods is that you get some idea of changes over time. Although one moth trap in one location is not a controlled dataset when the data from lots of traps run all across the country is combined a picture of change begins to emerge.

The longest running systematic survey data for moth comes from the Rothamsted traps, which have been run every night at locations all across the country since 1967. A summary of the results of this work was published (Macgregor, C.J., Williams, J.H., Bell, J.R. et al. Moth biomass increases and decreases over 50 years in Britain. Nat Ecol Evol 3, 1645–1649). The traps are of a standard design so the catches can be compared between sites and between years. It turns out that moth biomass, the total weight of moths of all types caught, actually increased between 1967 and 1982. Since then there has been a steady decline to the present. However there still seems to be almost twice the biomass of moths now that there was in 1967. Catches varied widely between years, with hot, dry years, such as 1976 resulting in large increases, so we might expect increases following the last two summers, time will tell.

Although the data does not go back before 1967 in such a systematic way, the evidence that is available suggests that the really big declines had already happened by 1967, following the large growth in pesticide use in the years following WW2. Comparing habitats the poorest are urban and arable areas, arable perhaps due to their uniformity and continuing pesticide use, urban areas although more diverse are still subject to light and chemical pollution, both of which probably have impacts. More natural habitats such as grassland and woodland have larger catches and might be expected to be more stable, but have actually suffered 18% and 15% decline respectively since 1983. Although numbers are lower, catches have been stable on arable land over the same period.

great oak beauty

great oak beauty – a moth of old woodland

It appears that the continuing declines are ongoing in the richest habitats but stable on the degraded ones, perhaps indicating that all habitats are declining towards an impoverished base level of bio-abundance, at least for moths. A similar pattern is suggested for other insects too and is supported to some degree by observations of long-term changes in bird populations across a range of habitats.

In recent years there has been a lot of enthusiasm for “Rewilding” and this does seem to be one way to start to reverse the wholesale declines impacting many species. It is certainly true that typically small, isolated nature reserves cannot maintain our biodiversity, but they do still have a vital role to play. They are biodiversity islands in a generally impoverished landscape. If the impoverishment can be reversed this biodiversity can start to spread out from the reserves and repopulate the wider countryside and urban areas. Nature reserves are not just slightly nicer bits of countryside, they are where we have effectively “Banked” much of our wildlife and so need special treatment if we are ever to rebuild wildlife richness across the country. Far from being irrelevant in a time of rewilding, nature reserves remain essential to rewidling achieving its full potential.

The breeding season seems to have been a good one for most bird species at Blashford Lakes. There are now well grown broods of little grebe, coot, moorhen and wildfowl all around the reserve.

coot family

coot family

One group that as fared less well are the ground nesters that use the lake shores and islands. Black-headed gulls are nesting only on the few available rafts, for the first time in over a decade none are using the islands. This may be due to predation last season, but in combination with no breeding around the lake shore by lapwing, I suspect that heavy disturbance, especially at night, is a very likely reason. Unfortunately lockdown started just as the breeding season got underway, which might seem a good thing, but it brought a huge increase in nighttime poaching activity on the reserve as people had more time on their hands and legitimate angling sites were closed.

gulls on a raft

Black-headed gulls are doing well on the rafts with lost of fast growing chicks

Luckily poaching activity has now declined again as angling lakes have reopened. Lockdown has seen lots more people out in the countryside and seemingly a much greater value being put on local greenspace, which is all positive. However, as has been widely seen in the media, it also seems to have resulted in a large increase in more careless use. Many reserves have suffered incidents, with fires being perhaps the worst in terms of wildlife impacts. It would perhaps be ironic if, just as more people have recognised the great value of greenspace, inconsiderate use resulted in some of its value being lost. If we value something we should be looking after it, ultimately nature reserve do not look after wildlife, we all do, we have banked some nature on our reserves, not so we can go in and burn a few pounds from time to time, but so we have seed capital to invest in a better future with wildlife across the whole landscape.

I will try and include more pictures and less verbiage in Day 10’s post!

 

Very Different Days

I was at Blashford again today after a couple of days off. I was last in on Thursday, when it rained all day and I left in a thunderstorm with hail and torrential rain. Today was quite different, warm, often sunny and altogether very pleasant. Both days produced notable migrants though, despite the very different conditions. On Thursday I arrived to find an osprey perched on the stick in Ibsley Water, the one that Ed Bennett and I put out there for the very purpose of giving an osprey somewhere to rest, it is always good when it works!

osprey in the rain

an osprey in the rain

Also in the rain a pair of Mandarin landed outside the new Tern Hide, they did not look much happier than the osprey.

mandarin

Mandarin in the rain

Today was more about butterflies, I saw good numbers of peacock, speckled wood, brimstone and orange-tip. But there were still migrant birds too, today’s highlight was a flock of 12 adult little gull, some in full breeding plumage and with a pink flush to their underparts, surely one of the best of all gulls in this plumage.

The other top birds today were the brambling, with 100 or more around the Centre and Woodland Hide area, many were feeding around the Woodland Hide giving great views, even I could get a half decent picture.

brambling male

male brambling

There are still small numbers of all the winter duck around, although numbers are declining day by day now. Today I saw nine goldeneye, although I am pretty sure there are still 11 around, there were also goosander, wigeon, teal and shoveler in small numbers. A few pairs of shoveler have been regularly in front of Tern Hide allowing the chance of a picture.

shoveler male

drake shoveler

Next week will see some further work at the Centre, with car park resurfacing and landscaping. There will also be some work at the Tern Hide at the end of the week, which is likely to mean that it will be closed for a day or so.

Also next week, In Focus will be doing optics sale in the Tern Hide on Tuesday.

Wetlands

This week has been busy working with volunteers at both Blashford Lakes and Fishlake Meadows. Both are wetland sites, rich in wildlife and the tasks have been aimed at maintaining this diversity of habitat and wildlife. The value of many wetlands lies not in the water itself but what grows in it or immediately around it and how these species and habitats interact. They form a mosaic including open water with lush marginal vegetation, these plants act as the support for a huge foodweb, although it is often only those species such as reed warbler or marsh harrier near the top that we notice.

So what were the volunteers up to? on both Wednesday and Thursday each team was managing scrub willow, to recreate open areas, allowing in light and restarting the habitat succession. In the past such work might have accompanied by a roaring bonfire, something I moved away from a good few years ago. I have several reasons for avoiding fires, they pollute the atmosphere, they sterilise the ground with their heat at the fire site, the ash acts as a fertiliser for hungry plants like nettle and thistle and the twigs and branches burnt are potential habitat for lost of species. For years we left log piles for beetles and other wood boring species, but the smaller diameter branches and twigs were ignored, despite the fact that they support even more species. So now we avoid fires and use dead hedges wherever we can. Ultimately the wood will break down and the carbon in it be released, but much more slowly and only after use by many other species.

volunteers working at Fishlake Meadows

Fishlake’s volunteers getting stuck-in shifting willow from a reedbed area to a new dead hedge.

At Blashford Lakes the terrain was a little drier and the areas opened up will support a mixed reed and dry fen vegetation, there is also an additional reason for clearance as this habitat is favoured by adder at Blashford. Many adder populations are in trouble, with some rarely producing young, luckily Blashford’s adders seem to be doing well and we see young snakes quite regularly.

Blashford volunteers

Blashford’s volunteers clearing scrub willow.

At Blashford we have combined the clearance of small willow with pollarding of larger ones to keep some dense willow growth favoured by many species. The dead hedges here provide valuable wind breaks for lots of wildlife including snakes and log piles placed in shelter are used for basking.

As it happens today is “World Wetlands Day“, this year’s theme is “Urban Wetlands – prized land, not wasteland“. Blashford Lakes is perhaps not an urban wetland, although it is not far from the town, but it is a prized wetland developed from a former industrial site, used for gravel extraction and making concrete products. Fishlake is perhaps a suburban wetland rather than a truly urban one, it is certainly right on the doorstep of Romsey town. In many ways it had been something of a wasteland since the abandonment of farming, but a “wasteland” that nature has reclaimed in a spectacular manner and well on the way to becoming a prize wetland site.

At dusk yesterday I was struct by just how valuable wetlands are for wildlife, from Ivy South hide I could see close on a thousand wildfowl, scattered all across the lake.

wildfowl on Ivy Lake

wildfowl on Ivy Lake

A little later still on Ibsley Water the huge gull roost emphasised how much wildlife depends upon wetlands, in this case as a roost site, as most of them spend the day feeding on farmland out on Salisbury Plain.

gull roost

A small part of the Ibsley Water gull roost with a few duck in the background.

Although the Thayer’s gull of last Sunday has not returned, this week has seen regular sightings of the regular ring-billed gull and on Wednesday and Thursday evenings a juvenile Iceland gull.