Friday, 25 March 2016

Quinta and Swettenham meadows 14th March

With another day of sunshine and an afternoon free I ventured over  to Quinta arboretum and wildlife trust reserve, and also the nearby Swettenham meadows. Temperatures were suddenly considerably milder and with this, the insects which have overwintered as adults, were becoming increasingly visible. After a busy weekend of bird ringing and some Barn Owl box repairs (a post for another time perhaps), it was enjoyable just to relax and enjoy the peace and quiet in the sun. Driving home the day previous I’d seen a butterfly - large, dark and strong-flying I suspect it was a Peacock (though a Red Admiral which are increasingly surviving our milder winters would be another possibility) - ID-ing a butterfly whilst driving is, admittedly, not the best way to do it! Another first for the year that weekend had been a large queen Buff-tailed bumblebee, so it was with these invertebrates in mind that I included Swettenham meadows in my wanderings.

Hoverflies which overwinter as adults have been tempted from their winter slumber and several individuals of the species Eristalis pertinax were basking in the sunlight on benches and branches, the one below a female (apparent from the spacing between the eyes, male hoverflies having eyes which meet together as a general rule) on a branch encrusted with common orange lichen (Xanthoria parietina). 

Female hoverfly Eristalis pertinax

Male dung fly
The humble dung fly can always be depended upon to provide a splash of spring colour - the males being bright yellow in colour with lovely golden 'fur' on their front legs. As you'd expect from their name, they have close associations with animal dung, visiting it to hunt their smaller insect (typically fly) prey, to breed, and for the females to lay their eggs.

Another splash of colour was found in the purpley-pink flowers of common lungwort, a pretty wildflower which blooms in late winter/early spring and is quite disctinctive with its silver spotted leaves. The plant has historically been used in herbal medicine as a treatment for various lung/respiratory conditions, originally because of the leaves' supposed resemblance to a diseased lung, hence its common name and also its latin name of Pulmonaria officinalis.

Flowers of Common Lungwort

7-spot ladybird
Meanwhile, several 7-spot ladybirds could be seen ambling along branches or huddled together in evergreens.

The buff 'tail' of a queen Buff-tailed bumblebee
One of the earliest of the bumblebees to emerge from hibernation, as well as one of the largest to visit gardens, Buff-tailed bumblebee queens were buzzed around noisily. Only the mated young queens survive the winter and they are most easily seen in early spring when they emerge and go in search of suitable nest sites, perhaps using an abandoned mouse nest, or just dense undisturbed vegetation. Some bumblebees (particularly Tree bumblebees) can take up residence in bird boxes. 

This particular individual was quite happy to sit still but with her head pushed into the grass - fine for identification but perhaps not so good for photography! As with many other insects, without sudden movements they are often quite tolerant of close-up photography, of course being respectful of the fact that they can sting. Unlike honey bees bumblebees can sting more than once and it is only the females that can sting. In several years of getting very close to them, I have never (at least not yet anyway!), been stung. 

Having seen a fleeting glimpse of a butterfly the previous day, I was keen to see if I could find any more which had been tempted from hibernation so I made the short walk between Quinta arboretum and Swettenham meadows, an excellent place locally for butterflies. (In the UK most butterflies overwinter as either a caterpillar or chrysalis but a handful hibernate as adults - Brimstone, Comma, Small Tortoiseshell, Peacock and increasingly with milder winters, Red Admirals.) Alas it was not meant to be, and another buff-tailed bumblebee was my only invertebrate sighting of note.

These are Oak Marble Galls induced by the gall wasp Andricus kollari, a very small and stumpy parasitic wasp.  These wasps have two quite different generations which complete their lifecycle, an asexual generation composed entirely of females and a sexual generation of males and females. Mated females of the sexual generation lay their eggs in the developing leaf buds of native oak trees, chemicals produced by the larvae cause this distortion of the buds. These galls provide a safe home to the developing agamic (asexual) females. The mature agamic wasps then leave in the autumn - you can clearly see the exit holes in the galls in this photo. This generation of wasps will then go on to lay their eggs in the buds of Turkey oak where the sexual generation of males and females develop in tiny egg-shaped galls, completing their complex lifecycle.   

Oak Marble galls

Trees were showing their readiness for the new spring with catkins - the cylindrical flower clusters produced by several types of tree, forming along the branches. Now admittedly my tree identification skills are pretty poor at the best of times, even more so when trees are leafless but I think that these are the male catkins (also sometimes called 'lambs' tails) of Hazel. (Unless of course someone tells me they're Birch....?)

Sunday, 13 March 2016

Early spring and early insects

A couple of quick catch-up posts from recent visits to Quinta and Sutton;

Quinta arboretum, Swettenham, 28th Feb.

The snowdrops were in bloom in their full splendour, not far behind were crocuses and daffodils, the primroses which has only been in bud at my last visit were now flowering.
I had wondered if with so many early spring bulbs in bloom whether I might spot any queen bumblebees tempted from their winter slumber by the gentle warmth of the sun. At only 6.5/7 degrees, this was perhaps being a little optimistic and invertebrate life was largely restricted to a few hardy gnats and flies. 

I did however look closely at some of the evergreen trees which are a great place to find ladybirds at this time of year in amongst the needle-like leaves. It didn't take long before I found two 7-spot ladybirds, one in the needles of a Western hemlock, then another in a Japanese ‘something-whose-name-I’ve-forgotten’. These clearly aren't native trees, but the principle is the same - one place 7-spot ladybirds favour to overwinter is in conifer foliage so these are good places to look out for them awakening in the early spring.

7-spot ladybird on Western Hemlock

7-spot ladybird (on something else...!)

Fur from European Rabbit

Clumps of fur lying on the grass were all that remained of an unfortunate rabbit, possibly predated by one of the many Buzzards that patrol the skies here. This image of a cross-section of the fur clearly shows the densely packed insulating grey/white fur, as well as the longer and coarser ‘guard’ hairs. 

We are so used to seeing rabbits here in the UK and hearing them being referred to as an invasive species (not forgetting that it was of course humans that introduced them in the first place) that they feel an unlikely mammal to have a conservation status of 'Near Threatened'. But that they do, and in their native range of southwestern Europe and northwest Africa, numbers have declined significantly due to the introduction of the generally fatal disease myxomatosis, as well as habitat loss and excessive hunting. In turn this decline has had a negative impact on the predators such as Iberian Lynx and Spanish Imperial Eagle which rely on them as a significant food source. 

Sutton Reservoir 7th March 2016

View across the reservoir to snow-covered hills in the Peak District
Lesser Celandine
The low-growing perennial wildflowers of Lesser Celandine were now starting to bloom, the bright and shiny yellow flowers are enjoyed by many insects, but again, it was just a little cool for much insect-life. The temperature was still only about 7/8C, and in the distance, snow could still be seen on higher ground. 
Ivy berries were plentiful, these being a great food source for birds such as Blackbirds and other thrushes when other berries are no longer available. (Just a quick reminder at this point that ivy berries are toxic to humans!)
Common Ivy berries

Gorse bushes were in flower and it was a pleasure to find the first honey bees I've seen of the year collecting pollen from them. 

With the severe declines of so many of our pollinating insects it almost comes as a relief to see them - we can only hope that [someday] our governments will take heed of scientists' recommendations when it comes to the use of certain pesticides/insecticides that are harming these and so many other vital insects [rather than the lobbying of the agro-chemical companies]. We only need to look to China to see a particularly unfortunate example of how the future could look.... there are areas where the insect populations have been decimated to such an extent that fruit trees are having to be pollinated by [human] hand. Sadly that doesn't seem to shock our politicians nearly as much as I think it should. 

Honey bee on Gorse