The female Wren is still sitting on eggs and only leaves them occasionally, to ferret for insects, beetles and spiders at the bottom of the garden, close to the nest. The male, which is polygonous and therefore may also have at least another mate on another nest (50% of male wrens do), feeds her occasionally but does not sit on the eggs, which take between 12-19 days to hatch. If we have to go near the nest, the male sings it’s loud alarm call and song. There are quite a few young Magpies visiting the garden at present They have yet to get the darker plumage and long tail of an adult. This one was working out, with its beady eye, whether it could reach the fat on our bird-feeder, and decided against it. After yesterdays blog, Scottish friends got in touch to say they heard many Cuckoos this year as they drove up the west coast of Scotland– that’s reassuring. Conditions: Cool and cloudy, but dry again. Temperature: Max 15- Min 11 c
I haven’t heard a Cuckoo this year but I have seen a Cuckoo Bee or two and here is a dramatic-looking one, called Nomada Flava. You may’ve seen the Bee Fly (featured on this blog on 14th April) on Springwatch last night with wonderful footage of it flinging its eggs into a Bumble Bee nest while still in flight. The Nomada is another insect which, like it’s `cuckoo name-sake, lays its eggs in Bumble Bee nests, and this one turned up a while ago in our garden. I couldn’t identify it myself so I submitted it to the wonderful http://www.ispotnature.org site, an initiative of the OpenScience Laboratory, supported by the Open University, and an expert identified it for me! Anyone can submit a photo and you can see all the other species people have uploaded, either as a record or, as I did, to get help with identification. Cuckoo Bees (there are several species in Britain) locate a genuine Bumble Bee’s nest, it is thought by scent, and then either kill the Queen and lay their eggs in the nest, or lay their eggs and the larvae hatch and kill the queen, eating the pollen stores and larvae of the host Bees. Though this sort looks a bit sinister, they don’t sting humans. Continuing the Cuckoo theme, many plants in the garden are hosting Cuckoo Spit at present. This has nothing to do with Cuckoos, except that it turns up during Cuckoo season, but is the protective bubbles excreted by Frog Hopper larvae. Frog Hoppers (more of these when the adults emerge) lay eggs into plant stems in late summer causing little damage to the host plant. The larvae hatch in spring, insert their syringe-like mouth-parts into the plant and excrete the sap, mixed with air bubbles through a special valve in its abdomen which acts like bellows! The ‘Spit’ protects from predation, maintains its temperature and stops the larva from drying out, until the Frog Hopper adult emerges.
Conditions: A dry day! Cloudy but still, no rain here all day! Temperature: Max 15- Min 11 C
Question- Why has the smoking ban helped Blue Tits? Answer: Because the outdoor wall-mounted ashtrays erected by many pubs, offices etc are increasingly being used as nest-boxes by the bird! While we await the fledging of Springwatch Blue Tits at the wonderful Minsmere RSPB Reserve, those in the garden continue to be fed by their adults, and will be fed for 2-3 weeks after fledging. Each Blue Tit nestling can eat up to 100 caterpillars a day and, as you can see, they continue to make huge demands for food after leaving the nest. Caterpillars are a protein-rich food, ideal for the growing young. Unsurprisingly, the presence of Blue and Great Tits can reduce caterpillar damage to orchards by 50%! However, that’s not the only interesting role caterpillars play in the life of Blue Tits. Female Blue Tits tend to prefer males with the brightest yellow chests, and the young are also very yellow when they emerge. This yellow coloration is created by carotenoids, pigments found in plants. These carotenoids are taken up from the tree-leaves by the caterpillars favoured by Tits. The more they eat, the more intensely yellow the Tits are, and of course, the young are fed hundreds before fledging. Research is being carried out to see
what role having a bright yellow chest plays in stimulating the adults to feed the young. P.S If you only saw 2 photos yesterday, scroll down for some added later Conditions: Another dull, drizzly day Temperature: Max 12- Min 10c.
Today we have fledging of tits! Despite a cool day of virtually non-stop drizzle and rain, young Blue Tits and Great Tits appeared in the garden, from neighbours nests, to be fed by rather frazzled adults, so I will leave the pictures to tell the story. Conditions: Rain and drizzle all day and night. Temperature: Max 12- Min 11 c
Galls have several causes- viruses, fungi, bacteria and insects, and appear on half of all plant species. In all cases, the host plant is invaded which causes the host plant to reorganise its cellular structure to provide nutrition, protection and/or shelter for the invading organism, in a parasitic relationship. Oak Apples, produced by Gall Wasps or Cynipids, are perhaps the best known galls, but a single Oak Tree, like the one we are lucky to have at the end of our garden, may support thousands of galls of different sorts without causing real damage to the tree. Over the last few weeks hundreds of these small Currant Galls have been appearing on the tree, with many falling onto the ground. The Gall Wasps that cause these Currant Galls to grow have a fascinating life-cycle. In autumn, eggs are laid on the backs of oak leaves causing Spangle Galls, which all hatch into female wasps. These are agamic, meaning they can reproduce without mating. In spring it is these which lay eggs in oak buds and catkins, generating Currant Galls, which hatch as males and females in June, mate and lay the eggs that form the Spangle Galls, and so it goes on. Gall Wasps not only cause the plant material to change form but cause the oak tree to produce more nutrients in the gall cells, to feed the larvae which hatch inside the gall. The larvae have sealed guts until just before they hatch, so they don’t foul their home! Even these little galls have been shown to creat mini-ecosystems for other lodgers, and they can themselves be parasitised by parsitoid wasps! More of galls another time I’m sure! Conditions: A dull, quiet, cloudy day, occasional very light rain. Temperature: Max 14- Min 10 c
Here’s a wildlife gardening plea to anyone who has a hedge with a gap, or garden space for an interesting small, slow-growing tree. I planted an Alder Buckthorn in the garden a few years ago, solely because it’s leaves are the key food plant for the caterpillars of the wonderful Brimstone Butterfly (they have started flying through the garden occasionally but I’ve never had caterpillars on it yet!). The more people who plant it, the more likely that colonies of the butterfly will build up! However, the tree has lots of other wildlife benefits– though the flowers are tiny they were covered with a range of bumblebees today, seeking nectar and pollen. The black berries are attractive to birds in the autumn, especially thrushes, and the leaves are beautiful with light shining through. Alder Buckthorn prefers dampish, acidic soil but will tolerate other soils and conditions. The leaves and bark make a good yellow dye. The wood was thought to make the best charcoal for gunpowder, was used to make wooden nails and, due to its even burning quality, was used to make time-fuses!
Conditions: Mild, still, dry morning with light showers building to light rain by evening. Temperature: Max 16- Min 11 c.
After a day and a half of sometimes torrential rain, the sun came out briefly late afternoon and we walked round the garden. Hanging on a strong but delicate thread of silk was this bright green caterpillar. I had trouble working out whether it was a Hawthorn Sawfly or a Green Oak Tartrix Moth caterpillar, both of which will fall while spinning a line of silk from their host trees, either to escape a predator or when dislodged by strong winds or rain. We watched this one slowly and painstakingly climb back up its thread, still being blown around in the wind, till it arrived on a Hawthorn leaf, which made me wonder about it being the Hawthorn Sawfly but if you look carefully there is another part of the thread leading up, and what is above the hawthorn is an oak tree! Also, Sawflies have more continuous legs down their body while caterpillars have pairs near the head and towards the tail, which, on downloading, this one looks to have. The Green Oak Tartrix caterpillar has a narrow time margin to survive- the eggs, laid near leaf-buds, have to hatch just as the new leaves emerge- before and they starve, later and the tannins building in the leaves are indigestible to it. Sometimes there are so many caterpillars they completely defoliate an oak tree!
Timing is also vital for their predators, especially Blue Tits as these caterpillars form the staple food of Blue Tit nestlings. After feeding up, the caterpillars roll themselves in an oak leaf, sealing it with silk, and pupate.
Conditions: Rain and more rain till late afternoon. Temperature: Max 17- Min 9 c.