Spring is in the Air

Hungry Mouths - © Edward Nurcombe

As I walked around the Reserve over the last week I found it hard to believe that less than a month ago we were caught in the grip of the coldest winter for over 30 years! The ice has since cleared from the lakes, the days are getting longer and at times, when the sun was shining, it has felt rather spring-like.

As I made my way along the Wet Marsh Path, adjacent to Tween Pond, I could hear a familiar sound coming from high in the trees on one of the islands – the clapping bills and loud, harsh chattering calls of Grey Herons that were busy tending to their nests. For this species in particular, spring and the breeding season had already begun.

The Grey Heron is the largest European heron species and is a top predator in the freshwater foodchain. They mainly feed on fish, amphibians and invertebrates which they catch with their dagger like bills. However, Grey Herons are not exactly fussy eaters and will also feed on small mammals, and occasionally even small birds and nestlings.

Grey Herons have a very prolonged breeding season that begins as early as February when most birds will return to the same nesting site they had used in the previous year. Once any repairs and renewals are made, four to five eggs will be laid per clutch that will hatch after 23-28 days of incubation. Grey Herons typically nest communally with other herons to form a colony or heronry.

Despite being present on the Reserve for a great number of years, the Grey Heron first bred on the Reserve as recently as 2004 - following a disturbance at their traditional breeding site nearby in Brandshill Woods. That year the heron’s nests were widely spaced throughout the Reserve and were even spread along the Trent Valley towards Nottingham. It was not until the following year that the herons came together within the islands of Tween Pond to form a more traditional communal heronry.

Seven years after it was first established the Attenborough heronry has now become one of county-wide importance - second only to the heronry at Besthorpe Nature Reserve. In 2010 a total of 32 nests were counted on the Reserve, many of which can be easily observed from the Main Path Bridge or along Wet Marsh Path.

Grey Herons are one of the species that suffer greatly during severe winter weather and this year’s heronries census will give us one of the first indications of the effect that the freezing conditions over the last few months have had on the Grey Heron population at Attenborough.

Once 'Bittern', Forever Smitten

A Bittern showing off it's camouflage in Clifton Pond Reedbed - © Harry McMahon

Harsh winters can often spell trouble for many of our resident and over-wintering birds. One of the greatest challenges for wild birds during cold periods is to find food and ensure that they eat enough to be able to build up adequate fat supplies to store on their bodies and burn for energy.

As 2010 drew to an end, we witnessed the coldest December on the Nature Reserve since local records began (1960). From late November, snow and ice began to spread across the lakes covering all but the smallest areas of open water. Concern grew for our over-wintering bittern population, an incredibly rare species of heron which has traditionally suffered during such cold winters.

As the bittern’s usual feeding areas, hidden deep within the reedbeds, became locked in ice, they were forced into the open to search for food. Through much of December and January visitors to the Reserve were treated to unprecedented views of up to four of these normally shy and secretive birds as they fed, rather exposed, in the outflow between Coneries Pond and the River Trent.

The bittern’s gold and brown striped plumage would otherwise make the perfect camouflage in their marshy habitat with extensive stands of common reed – making them very difficult to spot. When alarmed, they stop and stretch their neck and beak upwards. Markings along the neck imitate dry reed stems perfectly and the bittern has even mastered the art of swaying in the wind to really blend in with its surroundings.

Over the last week as the remaining ice covering the lakes receded, the bitterns returned to their usual feeding and roosting grounds of Clifton Pond and the Delta reedbeds. Despite almost two months of frozen water on the Reserve, it would seem as though the bitterns were unaffected. A total of five birds were counted returning to roost on Clifton Pond on the 15^th!

Causing a Stir!

The excitement surrounding the arrival of the bitterns each year at Attenborough is wholly justified when you consider the rarity of this species and their unsettled past. Drainage of wetlands and persecution led to the extinction of the bittern in the UK by the late 19^th century. They returned to breed in 1911 yet despite a steady increase through the 1950’s the population never reached more than 80 individuals. In 1997 the population crashed to its lowest number since the 1920’s, with just 11 males recorded! – Counting the number of booming males is the only way to accurately establish the population size.

Fortunately things are now looking up for the bittern. A combination of careful reedbed management and biodiversity action plans, which encourage the creation of wetland habitats, has meant that the population is now showing a positive recovery. A total of 87 males were recorded in the UK last spring!

Each year there is a programme of management work here at the Nature Reserve which includes maintaining the reedbeds for bittern and other wildlife. Staff and volunteers work tirelessly to remove willow saplings and dead vegetation that would otherwise cause this wetland habitat to dry out. As part of the recent floodwall mitigation, reedbeds have also been created on Coneries Pond, Church Pond and Tween Pond that are sure to attract species like the bittern to Attenborough for many years to come.

Rare Fungus Makes an Appearance

The 'Winter Stalkball Fungus'

It is coming to the end of the fungi ‘fruiting’ season at Attenborough Nature Reserve, but there is one species in particular that is receiving an unusual amount of attention. Tulostoma brumale, the Winter Stalkball, is a rare type of puffball fungus that has not been seen in Nottinghamshire for over 100 years! 112 years to be exact, with the last one being recorded in Colwick Park in 1898. This is a totally new species for Attenborough and was discovered during one of the Nature Reserve’s organised annual fungi identification courses, led by members of the Nottinghamshire Fungi Group.

Despite the fruiting body of the Winter Stalkball fungus being matchstick thin and only 2-5cm high with a 0.5-1cm puffball sat on the top, it caught the attention of an eagle eyed visitor who was on the identification course. The fungus was found hidden amongst the moss on the edge of Corbett’s Meadow adjacent to The Village Green. Tulostoma brumale is light grey/ brown in colour and on the top of the puffball is a papillate projection with a small opening, the ostiole, from which millions of spores are released in order for it to reproduce. A specimen had to be taken away by the fungi group for further identification before it could be confirmed as being this rare species. 

The Winter Stalkball is generally uncommon in the UK. One of the reasons it is extremely rare in Nottinghamshire is that it is normally found in sandy, alkaline soils and sand dunes where it is associated with mosses and short grass. This species was however more frequent during the Victorian era when lime mortar, used for construction, provided suitable growing conditions on old stone walls. Formerly a slag heap from the Beeston Boiler Company, Corbett’s Meadow, where the fungus was discovered, has now transformed into a species rich wild flower meadow. The low nutrient levels make the meadow ideal for a great number of native wild flowers including three species of orchid. It has been suggested that the lime used during the smelting process could still be present in the slag and the soil, and would therefore create suitable conditions for the Winter Stalkball fungus here.

229 species of fungi have been identified at Attenborough in the last 5 years through our organised fungi walks and from findings by local naturalists. The latest, Galerina laevis, was found by a member of the Nottinghamshire Fungi Group when he returned to photograph the Winter Stalkball! With names such as Dead Man’s Fingers, Jelly Rot, Toad’s Ear, Crystal Brain and Chicken of the Woods it is hard not to enjoy studying the many different species of fungi that can be found on the Reserve. Many species continue to ‘fruit’ into the winter months, so why not go out and photograph some fungi of your own? Please do not pick any fungi you find on the Nature Reserve. If you would like to find out more, the Nottinghamshire Fungi Group has a calendar of organised walks which runs from September through to December which includes some that are open to interested members of the public. For more information visit www.nottsfungigroup.org.uk

Autumn Migration - Birds on the Move

Common Tern - One of Attenborough's Longest Distance Migrants

With recent sightings of coastal waders such as curlew sandpiper, black-tailed godwit and ruff on the Reserve, it is clear to see that we are in the middle of that wonderful time of year that is the autumn migration. This is the annual movement of birds from their northern breeding territories to their southern over-wintering grounds and often involves journeys of thousands of miles.

For most of Attenborough’s summer breeding birds including nine warbler species, swallows, sand martins and the common tern this long journey south would have started back in September. However, through early October, birds that have bred further north can be seen as they move through the county on passage.

The use of visual landmarks such as the River Trent is one of the many ways in which birds navigate during their remarkable migration journey. It is the proximity of the Nature Reserve to the river that makes Attenborough a perfect ‘re-fuelling’ site for passage migrants (birds that appear for a short duration between their origin and destination). During inclement weather, species not normally found on the Reserve such as black tern are forced to land or stop off and re-fuel before continuing on their migration. In extreme cases North American or Continental European species that have been blown off their usual migration course might even make an appearance. Because of this, October is one of the most exciting months of the year to be out on the Reserve.

Bird migration has fascinated naturalists since the time of Aristotle. Back then, although migration was obvious in large species such as cranes and storks, it was inconceivable to think that smaller birds were capable of making such incredible journeys. Until the early 1800’s, it was still widely believed that swallows hibernated in the mud at the bottom of ponds. Bird ringing studies have long since disproved traditional theories about migration and have provided fascinating insights into the movements of birds.

Last year a ringed common tern (pictured) was regularly seen feeding around the reedbed at the front of the Nature Centre. As it came to perch on the fence posts and handrail, the ring number could be easily read. It turned out that this bird was originally ringed as a chick in Oxford in 1997! We know from previous ringing data that the common terns ringed at Attenborough migrate to Senegal in Africa for the winter. That would mean that this bird has already flown over 90,000 miles in its lifetime!

As the common terns that have been with us for the summer leave, it is not long before wintering ducks start to arrive. Over 1% of the country’s population of shoveler reside at Attenborough for the winter. Male and female shovelers stir up the water by swimming in a tight circular formation. They then use their strange spatulate bills to filter insects from the surface. By the end of October, goosander, goldeneye, wigeon, pochard, and teal will have joined the resident mallards, gadwall and tufted ducks on the vast water-filled gravel pits.

By November you might even get a chance to glimpse the rare bittern skulking through the reeds. This scarce species of heron became extinct in the UK by the 1900’s. They returned as a breeding species some 15 years later however even now they number fewer than 100 pairs. The bittern’s cryptic camouflage enables it to blend in perfectly with its reedbed habitat as it hunts for fish. Last year up to seven could be seen over-wintering in the reedbed on Clifton Pond.

Batty about Bats

It is a little known fact that this weekend (28^th-29^th August) is European Bat Weekend, an annual celebration of bats organised by The Bat Conservation Trust.

With seven of the UK’s 17 breeding bat species having been recorded at Attenborough Nature Reserve, the news of the forthcoming bat celebration spurred me on to dust off my bat detector and go out looking for some of Attenborough’s rarely seen nocturnal mammals.

Following a few nights of heavy rain, the forecast clear sky last Monday night was sure to attract large numbers of hungry bats that would have been unable to feed during the bad weather. Despite a strong wind (and a heavy down pour half an hour before leaving the house) I was not to be disappointed.

Just after dusk and only 10 minutes after arriving on the Reserve my bat detector started to make some strange sounds likened to wet slaps, that without the detector were inaudible to the human ear. These were the sonar calls made by my first bat of the night, a Common Pipistrelle. This is Britain’s commonest bat which weighing only 5g (less than a 2p coin) is also one of the smallest. In spite of its small size the Pipistrelle’s voracious appetite means it can consume around 3000 insects in a single night!

A few minutes later and having tuned the detector to a different frequency, a Noctule Bat, one of the largest species in Britain could be heard as it cruised along its feeding path over The Bund. The characteristic ‘chip chop’ call of the Noctule was replaced regularly with a series of ever increasing clicking sounds as the bat homed in on its insect prey.

With the going good, I moved to the Works Pond bridge. Here, the sounds coming from the bat detector became hard to distinguish as large numbers of Pipistrelles and Noctules were busy feeding over the pond and along the marginal vegetation. All of a sudden the higher frequency call of a Soprano Pipistrelle came in to range as it joined in the feeding foray. So similar is the Soprano to the Common Pipistrelle, that this bat was only identified as a separate species in 1990.   

As I walked through the Reserve towards the Nature Centre, bats could be heard from all directions. Even in Attenborough Village Common Pipistrelles could be seen patrolling the street lamp lit roads. Over Coneries Pond surrounding the Nature Centre I encountered my final species of the night, the rare Nathusius’ Pipistrelle, first recorded in Nottinghamshire at Attenborough Nature Reserve in 2006. What a way to end a very exciting night bat detecting.

How can you get involved?

September is one of the best times in the year to go out looking for bats. Numbers will have increased from mid July through to August as juvenile bats born in June start to fly. Furthermore it is the start of the mating season for next year’s brood so many males will be seen busy flying around and using their special mating calls to attract a female.  September is also the time when bats begin to concentrate on building up their fat reserves to see them through the winter.

If you’re looking for a place to start, a basic bat detector will help you get the most out of bat watching and will aid correct identification. You can purchase a heterodyne detector from the Nature Centre for as little as £69. These detectors change the ultrasonic sounds emitted by bats into sounds that we can hear and can be tuned to the frequency of ultrasound used by different species.

Disappearing Ducks

Where have all the male ducks gone? As you look around the Nature Reserve you may have noticed that all of the brightly coloured drakes seem to have disappeared. The male mallard with its iridescent green head, purple brown breast and grey body, or the contrasting black and white of the male tufted duck can simply no longer be seen. So where have they all gone? You may be surprised to know that they haven’t actually gone anywhere they are just undergoing their post breeding moult known as ‘eclipse’.

Feathers are extremely important to birds. They are vital for flight, provide insulation and have evolved into a massive array of colours and patterns to be used in courtship and sexual selection. Bird’s feathers often wear out during the year through flying, exposure to the sun, rubbing against other feathers and parasites such as lice and mites. Feathers therefore need to be regularly replaced and moulting is the process of shedding and regrowing them. Unlike most other birds’ ducks, geese and swans lose all of their flight feathers at once leaving them flightless for a few weeks.

The moult process in mallards starts by shedding the bright coloured body feathers which are replaced with the dull brown feathers seen in the ‘eclipse plumage’. This makes the males look a lot like the females and provides them with some camouflage during their vulnerable flightless period. After the flight feathers have regrown, the birds go through a second moult phase, and by October the male’s full colours will have returned.

Bee Orchid Discovery

The first record in over 20 years

 In the last week there has been an exciting new addition to the Nature Reserve that strangely coincides with the discovery of a locally rare bee orchid found on Corbett’s Meadow after an absence of over 20 years, and a species of bee that has been spotted for the first time at Attenborough.

Last Thursday under the cover of darkness (when the bees are back in their hives and are settled), six bee hives were put into position by Park’s Apiaries on one of our flower rich meadows. The bees, it is hoped, will augment the wild bee population on the Reserve and help to pollinate the diverse wild flower assemblages that can be found here. They will also provide a tasty treat of locally sourced and sustainable Attenborough honey that will be sold in the Nature Centre later in the year.

16 different species of wild bee have been recorded on the Nature Reserve since records began, including the tree bumblebee (Bombus hypnorum) which was seen for the first time at Attenborough this June. The tree bumblebee, which likes to nest in holes in trees, is common and widespread over much of mainland Europe and first arrived on the south coast of England from France in 2001. It has slowly moved north reaching nearby Leicestershire in 2009. It has a distinctive brown thorax, black abdomen and white tail so is unlike any other native species. This species can often be seen along the Wet Marsh Path towards the observation point overlooking Clifton Pond.

Despite this new arrival, native UK bee populations have suffered a catastrophic decline over the last 30 years. Three species have recently become extinct and many more are now seriously threatened. This is thought to be the result of a number of factors including loss of wildflower habitats, agricultural intensification, use of pesticides and emerging parasites and diseases. 

As bees play an important role in pollinating wild flowers and almost a third of all commercial crops, the recent declines are cause for concern. Albert Einstein is reputed to have once said that without bees to pollinate our food crops, humans would die off in just 4 years!

To help restore valuable meadow habitats, the Nottinghamshire Wildlife Trust are giving away Mini Meadow seed packs which will provide all you need to share your garden with nature. Each pack contains enough seed to create a 1m² Mini Meadow, wherever you have space and the mix has been specially selected to attract pollinating insects such as bees. You could sprinkle it on a bare patch of soil, or use to transform an area of your lawn. You could even create a Mini Meadow in a window box or a hanging basket. Packs are available to Nottinghamshire residents from support@nottswt.co.uk or the Attenborough Nature Centre (one pack per household).