Dolphin School Eye Spy at Dolphin

Eco Warriors
Eye Spy at Dolphin
By Claire
Apr 19, 2009 - 4:34:19 PM

Tony Towner is delighting and informing us as he photographs and details the biodiversity at Dolphin School.

09/01/12 – Pale Brindled Beauty Phigalia pilosaria -

For anyone interested in Moths, it is always exciting to see the first one of the New Year. Here at the Dolphin it never takes very long, due to the numerous broadleaved trees and shrubs that surround the school.

The larval foodplants of this species include Oaks, Hawthorn, Apple, Hazel, Poplars, Elms and Ash, which are all found in the grounds of the school.

The flight season is from January to March, and occasionally in late December. The flightless female is regularly found near the base of tree trunks, just after dawn. The male comes readily to light, often in large numbers in woodland.

To survive the winter and the cold weather, most invertebrates either migrate or hibernate in some form or another. However, there are a few who use their body fluids to protect themselves against the cold, and these come in the form of “anti-freeze” chemicals.

15/12/11 – Orb-web spider Nuctenea umbratica -

I was carrying out my annual clean of the Dolphin nest boxes, when I noticed that a pair of these handsome spiders had taken up residence in one of them. They have a shiny, flattened abdomen, which allows them to hide under the bark of trees during the daytime. They emerge just as it is getting dark to spin a new web for catching moths or other night flying insects.

Without wishing to cause any alarm to any arachnophobiacs out there, this spider is capable of biting humans, causing itchiness and a burning sensation followed by a red patch with white lumps. In this country, 90 to 100% of spider bite cases are caused by no more than 12 of the approximately 700 native species. It is worth remembering that they will only bite in self defence.

When disturbed, this species doesn't run off towards the nearest cover, but tends to sit very still with a habit of tucking its legs tightly up against its body, allowing easy photograph opportunities.

When finished, I carefully re-located the pair to another tree.

29/06/11 – Green-veined White Pieris napi -

I found these two butterflies mating amongst the meadow area of the pond during my lunch break. Although this species is one of our most widespread and commonest, it is often mistaken for the Small White butterfly. The yellow underside of the hindwings reveals conspicuous dark ‘veins’, which are absent on the Small White. This species also has a rather fluttery flight compared to the more direct flight of the Small White.

These butterflies are a very adaptable species and are found in a wide variety of habitats from hedgerows to riverbanks. Damp, lush vegetation is an essential requirement so they can often be found near damp meadows such as the Dolphin pond.

The Caterpillar foodplants include Garlic Mustard, Charlock, Hedge Mustard and Cuckooflower. There is an abundance of Garlic Mustard around the pond area, so hopefully our female will choose to lay her eggs there.

28/04/11 – Mallard ducklings -

Mrs Mallard has produced 12 ducklings as can be seen from this photograph. She decided to forgo the luxury hotel that we built for her, and instead took advantage of the lovely unseasonal weather by nesting on the straw outside.

I saw the first duckling poking its head up from underneath her late on Wednesday the 27^th. It then normally takes at least a further 10hours for them to dry and get used to using their legs. In the early morning the next day, the mother then encourages them into the water to start feeding. The nest is abandoned, but if close to the feeding site, the mother will use it for brooding and roosting. This behaviour was observed at the Dolphin pond.

Unfortunately, as soon as the ducklings took to the water, the local cats appeared on the scene, waiting for any ducklings that were foolish enough to stray onto the bank vegetation. I fenced off a particular sheltered bank with chicken wire to try and keep them at bay. Also, at one stage both the male and female flew away from the pond, causing the ducklings to huddle together in the middle of the pond. They cannot survive without their mother, and take 50-60 days before they fledge and become independent. Fortunately the mother returned a short time after.

The following morning after the pre Royal wedding sleepover, some of the children saw the Mother and ducklings walking through the playground towards the farm behind the log cabins. It is hoped that Mrs Mallard has found another body of water where she feels safer with her brood. Maybe when she flew away with the male it was to do a quick reconnaissance mission to find a new home. They have been known to travel a couple of miles to find water.

21/03/11 - Mallard duck house -

Af ter the success of the blue tit nest box, we (Alex and Tony) decided to build one specifically for Mallards. Using re-cycled materials and off cuts of wood, Alex was in charge of the floating platform and I was in charge of the nest box. Imagine our excitement when shortly afterwards the two Mallards in the photograph showed up. As far as we can tell, the female has not been inside the box, but seems quite happy snuggling down in the straw outside.

Mallards start to pair up in October and November, and start to nest in March. They prefer to nest near water and the duck generally makes her nest well covered in vegetation or in a natural hole in a tree. The female builds a nest from leaves and grasses and lines it with down plucked from her breast. Eggs are laid between mid-March and the end of July. The normal clutch is about 12 eggs, laid at one to two day intervals. After each egg is added, the clutch is covered to protect it from predators.

Mallards eat seeds, acorns and berries, plants, insects and shellfish. The female should be able to find food for herself while she incubates, but you could put out a bowl of drinking water, together with duck pellets and cooked potatoes for her to eat. Put these in an accessible area some distance from the nest.

Whether this Mallard decides to stay and lay eggs will probably be down to how much food is available, and whether she feels safe from predators. This is a natural wildlife pond which has been stocked with ornamental fish. This creates a conflict of interests as regards food for the duck and the fish.

09/03/11 - Minotaur Beetle Typhaeus typhoeus -

I rescued this Beetle just before lunchtime today, as it crawled across the playground outside the basilica entrance. This is a type of dung beetle, which is usually found mainly in sandy places, where it buries rabbit or sheep droppings, on which adults and larvae feed. Dung beetles can be conveniently divided into three groups, Rollers, Tunnellers and Dwellers. Rollers are more usually found in the tropics where they are far more successful, but in Britain we have one only - The Minotaur Beetle. Rollers are species who make a burrow some way away from the dung they are going to use and then collect small to medium sized lumps to role away from the source and into their burrows.

The Minotaur Beetle is also known as the "winter beetle" as it emerges in late September after rains, and then reaches sexual maturity during a maturation feeding period, ready to nest in December if the weather stays mild.

The male is a very striking insect with three thoracic horns, but the female shown here has just two small thoracic points. They usually fly at night and my guess is that this one was attracted to the playground floodlight.

28/01/11 - Spring Usher Agriopis leucophaearia -

Whilst unlocking the school during the dark and dreary mornings of January, it is heart-warming to find that there is still plenty of wildlife about. This comes in the form of several moth species. One of these is the Spring Usher shown here, which was found attracted to a lighted window by the Art room door. The flight season of this moth is usually early February - mid March, but can be found from early January depending on the pattern of mild nights. This one was found on 28th Jan.

The Art room and Meadow reception doors are two good places to hunt for moths in the early morning and so far this year I have found the following species: Winter Moth, Mottled Umber, Pale Brindled Beauty, Early Moth and Spring Usher.

12/10/10 - Noctule bat -

Just before half term, there was great excitement in the quiet garden when a group of children found this bat at the base of one of the apple trees. As it is unusual to find a bat out in the daytime, I decided to contact the Bat Conversation Trust (BCT) for further advice. Firstly, to avoid predation from a cat, I was told to gently transfer the bat into a shoe sized box and place a piece of cloth in one corner to allow it to hide and feel safe. Secondly, I was told to place a shallow container in one corner, such as a milk bottle top, and fill it with water. This was done with gloves on as there is a small risk of a bite or a scratch from a distressed bat, which could lead to the transfer of a rabies related virus. Having done all this, it became obvious that the poor bat was injured and would have to be treated by the local vet.

Unfortunately, there was no happy ending to this story, as the vet had to put the bat down, due to a fractured wing. I took this final photograph at the vets, which to me shows what an endearing and lovely animal a bat is.

The species is a Noctule bat Nyctalus noctula, which is one of the largest in Britain, and is usually the first bat species to appear in the evening, sometimes even before sunset. Noctules have broad brown ears and a distinctive mushroom-shaped tragus (fleshy prominence at the front of the external opening of the ear). They fly in the open, often well above tree-top level, with repeated steep dives when chasing insects. Their diet consists of Moths, beetles (mainly chafer and dung beetles), mayflies and winged ants.

St Mark's-Fly - Bibio marci is a very common fly that everyone can recognise at Dolphin. The males are very obvious as they can be seen flying in swarms on the field with their dangling legs.

Here is a mating pair clearly showing the differences between the male and female. The male is the lighter of the two with large bulging eyes, and the female much darker with smaller eyes.

This fly is named for its appearance on or around St Mark’s day (April 25th)

Spotted Crane-Fly - Nephrotoma appendiculata is very abundant during the months of May and June and can be found around the field and pond.

They are also very common in gardens and the larvae can be destructive in the vegetable garden, feeding on roots and tubers of brassicas and potatoes.

When the wings are open, the abdomen is a brightly coloured yellow and black giving it the nickname of ‘Tiger’ Crane-fly.

Cockchafer or May Bug - Melolontha melolontha is a very common Beetle found around the school during May and June.   I have even seen it on Mr. Leakey’s classroom door waiting for a German lesson.

It flies clumsily at night with an audible humming sound and can cause alarm when entering lighted windows.   It feeds on foliage, with a preference for oak and apple, which are abundant at Dolphin.

Males have well developed, fan like antennae which are very striking to look at.   The specimen above must therefore be a female as these are clearly absent.

Redwing - During the cold spell early January, I was lucky enough to photograph this Redwing, which is rather an unusual visitor to the Dolphin school grounds.

The Redwing is a winter visitor to this country and migrates from Iceland and Scandinavia. They normally eat fruit and berries in the autumn and winter, but with all the snow and ice around, their usual food source must have been increasingly difficult to find. Hence I found this one turning over leaves like Blackbirds do in the compost area of the orchard, presumably trying to find some invertebrates.

Redwings belong to the Thrush family of birds and are somewhat smaller in comparison to our commonest Thrush, the Blackbird. The main identification features are the whitish stripes above the eye and beneath the cheek, and by the rusty-red flanks when perched or by the rusty-red underwing when in flight.

Now that the snow and ice have retreated, the Redwing has moved on to its more usual food supply.

Dragonfly - With the warm weather this autumn there has been much opportunity to study the many species of dragonfly that we are lucky enough to have around the Dolphin pond. The handsome species above shows a male Southern Hawker dragonfly that I found resting and basking in the sun towards the end of September. There are certain identification features that we have to look out for that distinguishes this species from Migrant, Brown and Common Hawkers that are also around the Dolphin pond during September and October.

Brown Hawkers, as the name suggests, are predominately brown and so we can eliminate that species. However, Migrant and Common Hawkers could possibly be confused with Southern Hawkers and therefore it is worth noting these differences. Firstly, there are two broad apple-green vertical stripes between the head and the wings on top of the thorax known as antehumeral stripes. These are narrow or almost absent on the other two species. Secondly, there are paired spots on each segment of the abdomen except for the last two segments (S9-10) which are stripes. The other Hawkers have paired spots on every segment. These markings are apple-green except for the last three segments (S8-10) which are sky blue. The Migrant Hawker is predominately blue on the abdomen and the Common Hawker blue with yellow flecks.
The behaviour of this species is also quite interesting and helps in identification. Males will closely investigate human intruders that are in their territories, hovering about waist height just in front of them before returning to their regular beat.

Purple Hairstreak butterflies - I have been lucky enough to discover a small colony of Purple Hairstreak butterflies in the Ash trees at the far left hand corner of the field. This is a very difficult species to find and observe as they spend most of their life up in the tree canopy. Unlike most of our native butterflies, this species shows little interest in the nectar of flowers and instead feeds on the sugar-rich honeydew deposited by aphids on oak, ash and aspen leaves. The photograph shows the butterflies proboscis inserted into the leaf of the ash tree.

Identification of the male is by a purple sheen with dark borders on the upperside compared to just a flash of purple on the forewing of the female. The underside of both sexes is similar, with prominent white lines on a greyish background, and orange-yellow spots near the corner of the hindwing.

The Purple Hairstreak has one generation a year and flies from late June until early September. They are reliant solely on the oak tree to complete its life cycle. The eggs are laid singly at the base of an oak leaf-bud and the small caterpillar remains inside the egg until the following spring. During March the young caterpillars emerge and start to feed within the leaf-bud. After six weeks they change into a plump brown chrysalis which is formed on the ground and is capable of making a rasping squeak to attract the attention of ants. Protection from attack by parasitoids and other small predators is gained from the ants, in return for a sugary meal exuded from a gland on the back of the chrysalis. The ants usually cover it to hide it, or transport it into their nests at the base of oak trees.

Grass Snake - On the 16th June, there was great excitement when a group of Year One girls found this small grass snake under one of the turfs by the tennis court fence. As the snake was getting agitated by all the sudden attention it was getting, I transferred it into the meadow area of the pond. There have been several sightings of adult grass snakes swimming in the pond and I have also seen one coiled up basking in the sun on the rubber mats leading up to the caretakers shed.

The Grass Snake is the longest of our three British snakes and can clearly be identified by the light yellow/cream collar just behind the head, as shown above. Grass snakes feed on tadpoles, frogs and toads, as well as fish, newts, and occasionally mice and small birds. Most hunting is done underwater, and prey is typically swallowed alive. They are good swimmers and do so with their heads out of the water, but if disturbed, will dive underneath and hide amongst water weeds where they can remain for up to an hour

Grass snakes mate in April-May. The female lays 8-40 eggs, depending on her size, in July-August in a warm site such as a compost heap or under rotting logs. The young snakes have an egg tooth to help them hatch out of the leathery eggs in late August-September.

They are active during the day and spend time basking in the sun to warm up. They hibernate from October to March, often communally in old rabbit burrows, wall crevices and under tree roots.

Caterpillar - Moth - You may recall that I was trying to trace the source of the food that the Blue Tits were feeding to their young.

I found this caterpillar on my rucksack after standing under one of the many Oak trees situated around the school, and I believed this could be the source of food. I took it home and on that same day it started to spin a cocoon. I placed it in my rearing tent and after 3 weeks it changed into the moth, a Ptycholoma Lecheana. There must be hundreds and thousands of these caterpillars around the school as it takes approximately 15,000 caterpillars to raise a brood of Blue Tits.

Nestbox - I put this nest box up earlier in the year on a tree in the pond area, and luckily a pair of Blue Tits took up residence. If you watch carefully, the adults are feeding their young every couple of minutes with tiny green moth caterpillars. I’m currently trying to trace the source of the food as I would like to know what species of Moth these caterpillars belong to.

The female lays 7-13 eggs in April-May, which she incubates for about 15 days. During this period, the male defends the area around the nest site from other Blue Tits, so protecting the available food needed for both adults and, later, the young. This is probably the reason that our camera nest box by Meadow building reception is not being used. Next year, funds permitting, I would like to try the camera nest box on this particular tree. The chicks will then fledge after 19 days.

Mallard - Look out for this male Mallard on his favourite tree stump in the pond area. He tends to be there first thing in the morning, but as he does not like too much disturbance, he usually disappears around mid morning break. Sometimes he brings a female with him, and I will try and photograph her at some other time to show the differences.

The main identification features are the metallic green head, narrow white neck collar, purple-brown breast and grey back.

The Mallard is classed as a surface feeder or dabbling duck rather than a diving duck. As it does not dive, the legs are positioned near their centre of gravity in the mid-body. This helps them to ‘spring’ from the surface of the water when flying off. Diving ducks have their legs positioned further towards their tail end, which means they usually need a run up to get airborne.

Large Red Damselfly - During the sunny weather last week there were many of these Damselflies feeding in patches of sunlight around the pond area and the shrub borders outside the Basilica. This species is the first one to emerge in spring and is known as the Large Red Damselfly.
The other red species to be found in Britain is the Small Red Damselfly, but unless you have the two side by side, it is not always easy to distinguish by size alone. The easy way is to check the colour of the legs. The Large Red has black legs as shown above, and the Small Red has reddish legs. Also, the Small Red does not emerge until late May and is normally found in boggy heathlands.

OakBeauty - This moth was photographed on Wednesday 18th March after Tony found it attracted to a lighted window in Meadow building reception. The species is the Oak Beauty, which is common and well distributed in south-east England . As the name suggests, the caterpillars feed on oak trees as well as other deciduous trees. The flight season is late February-April.