The International Union for the Conservation of Nature (IUCN) publishes the Red List.   It is a list of species that are under threat in different parts of the world; it goes back to 1964 when it published the ‘list of threatened plants’. By 2012, the IUCN assessed a total of 63,837 species and reported on their status in the following terms: Extinct (EX) – No known individuals remaining. Extinct in the wild (EW) – Known only to survive in captivity, or as a naturalised population outside its historic range. Read more...

You may well have heard that bees are in trouble. Domestic honeybee hives seem to die more often than they used to, and some of our wild bees have disappeared altogether; for example, three of the UK’s twenty seven bumblebee species have gone extinct. The big, long-term driver of declines has been farming intensification; where once we had plentiful hay-meadows and chalk downland, rich with flowers, we now have flower-free monocultures of wheat or silage grass. Pesticide use is also contributing to the problem, particularly new generations of systemic, persistent insecticides called neonicotinoids that get into nectar and pollen of both flowering crops and wildflowers. Read more...

Following on from last week's post, the woodlands blog has often reported on the problems facing honey bees and bumblebees - from the vagaries of climate to the effects of insecticides, such as neonicotinoids.  Whilst it is easy to identify a honey bee and spot a bumblebee, it is somewhat more difficult to say what type of bumblebee might be foraging in your garden or woodland. There is a lot of information about bumblebees at the bumblebee conservation trust website.  A particularly useful link is "Top tips for bee ID"; tail colour is an important or helpful feature.  Read more...

DDT was used an insecticide at the onset of WW2, with great success in terms of controlling malaria and typhus among civilians and troops. After the war, it was available as an agricultural insecticide.  However, within a few years, there were warning signs that not all was well and in 1946, the Soil Association journal read as follows "By the wholesale use of powerful insecticides of which far too little is yet known, we may well be upsetting the whole balance of Nature. We are like schoolboys rat-hunting in a munition dump with a flame-thrower." Some years later (in 1962),  Rachel Carson published ‘Silent Spring’ – which seriously questioned the use of organochlorines, such as DDT and warned of the dangers of the indiscriminate use of insecticides.  The use of these chemicals continued Read more...

The Bumblebee Conservation Trust, based at Stirling University, needs your help in recording sightings of bumblebees. They would like you to record what species you see, where and how many, and take pictures of any unusual specimens. Go to http://www.bumblebeeconservationtrust.co.uk/surveys.htm to find out how to take part. Read more...

Bumblebees are regarded as nice, gentle creatures; even their buzzing has a placid, reassuring sound. They rarely sting and are important pollinators in orchards, on farms and in our gardens. Sadly, however, they are under threat. Many species of bumblebee are on the decline and have been, according to some authors, since the late 1950’s. Their decline is often attributed to the introduction of intensive agricultural techniques. For example, Read more...

A plant growing in the wrong place is sometimes described as a weed, but it can be more than just an inconvenience.  Plants in the wrong place can have a devastating effect on ecosystems, dramatically reducing biodiversity.  The same is true for certain animals - those that have 'traveled' from their natural habitats to 'foreign areas’ where they have no natural predators to keep their numbers in check.  Foreign or alien species are sometimes introduced to an area in the belief that they will solve local problems with pests or over-population of a native species.   A classic example of this is the cane toad.  Native to  parts of central and South America, the cane toad is preyed upon by a variety of animals such as caimans, snakes, eels and some fish species.  It was introduced into sugar plantations in various parts of the world to control beetles that were damaging sugar cane crops. Since this was a successful strategy in Puerto Rico, the toad was introduced elsewhere, notably Australia.  Just over a hundred toads were released in Queensland in 1935, with more released in 1937.  Unfortunately the toad did not effectively control the grey-backed cane beetles (the intended target), and they found other things to eat.  Their numbers grew exponentially and they spread into other areas, such as the Northern Territory and New South Wales.  These poisonous toads have significantly reduced biodiversity particularly affecting native amphibians and reptiles. Sometimes foreign species are introduced as ornamental plants or 'exotics'. During the Victorian period many plant species were brought to the UK for country estates.  Rhododendrons that were collected across Asia and the Himalayas became popular in parks and gardens.  However, Rhododendron ponticum, a species native to the southwestern Iberian Peninsula (parts of Portugal and Spain) and the southern Black Sea Basin (parts of Bulgaria & Turkey)  has been less well received.   It was introduced in the eighteenth century by Conrad Loddiges.  Loddiges grew seed and sold on young plants as an ornamental flowering shrubs for gardens, parks and estates. On country estates and heathland areas, it was planted as cover for game birds as its dense growth offered shelter and protection. It has since spread aggressively and is now considered to be an invasive species. An invasive species is a non-native species that spreads and damages its new environment. R. ponticum poses a threat to key woodland ecosystems, such as Atlantic Oak Woodland.  When this shrub ‘invades’, it comes to dominate the area.  It creates deep shade so the woodland floor becomes a dark and ‘barren’ place. Many ground flora species are lost so that only shade tolerant mosses and liverworts remain.  These plants form a ‘dense mat’ of vegetation that is a barrier to seed germination.  Additionally, there is evidence that as R. ponticum grows, it produces chemicals which inhibit the growth of other species.  This phenomenon is known as allelopathy.  Even when the Rhododendron is removed, it is difficult to reestablish the original flora.  Clearing an area of this plant is difficult and expensive. One effective method involves drilling the stems and injecting herbicide directly into the plant, a targeted approach that uses a lot less herbicide than spraying.  Mabberley’s Plant-book notes that the cost of eradicating the plant from Snowdonia was £30M and that was in 1988. Another Victorian introduction was the grey squirrel. Native to North America, grey squirrels were first released in the UK in the latter part of the 19th century.   One person associated with their spread was the 11th Duke of Bedford  (Herbrand Russell).   He was involved in various animal conservation projects, but he released and 'gifted' many grey squirrels from the estate at Woburn.  The populations of grey squirrels in Regent's Park, London are thought to have come from there. Humans may still be helping the spread of the grey squirrel, albeit unintentionally.  One squirrel was captured on the Isle of Skye (in 2010), it had traveled from Glasgow, as revealed by its genetic profile.  It had probably made the journey as stowaway under a car bonnet. It is important that we are aware of how 'easy' it is for these animals to travel with us.  Their introduction has been disastrous for the native red squirrel populations, due to competition and the spread of the squirrel pox virus.  It is vital that grey squirrels do not colonise areas where the red squirrel still survives. . More recent introductions have arrived due to increased global trade.  Parasites and pests can ‘hitch a ride’ with people, materials or goods as they move across the world.   Climate change is also altering the range and distribution of many plant and animal species.  There is an alert for the Asian or Yellow Legged hornet (Vespa velutina nigrithorax), an invasive, non-native species from Asia.  This hornet preys upon honeybees and other beneficial insects such as hover flies and bumblebees. It hovers outside bee hives, waiting to catch and then kill returning honeybees. The effect on bee colonies can be devastating. The Asian Hornet arrived in France in 2004 (through an import of Chinese pottery) and has spread rapidly. Now it is found in Italy, Spain, Portugal, Switzerland, Belgium and Germany.  Preventing its establishment in the UK is critical.  Any sighting needs to be reported, this can be done through the Asian Hornet Watch. This link downloads a PDF, which gives more information about the Asian Hornet, and contains images comparing the  appearance of the asian hornet, the european hornet, the wasp and honey bee. Other invasive species that are a cause for concern include : Himalayan Balsam Harlequin ladybirds, Signal Crayfish, Eight-toothed bark beetle Citrus long horned beetle Giant Hogweed Thanks to Anton for images.

Insect pollinators are currently in decline.  This is, in part, due to the loss of habitats and foraging resources for pollen and nectar.  Pesticides, like the neonicotinoids, don’t help. Lawns and pollinators. “No mow May” has been promoted by Plantlife to  provide a feast for pollinators,  tackle pollution,  reduce urban heat extremes, and  lock away atmospheric carbon Lawns in gardens, parks, recreation grounds etc. represent a significant proportion of green space in cities, towns and villages. If these spaces and suburban lawns are managed with pollinators in mind, then they could become an important source of foraging resources.  Now, there is evidence accumulating that this is the case.  A  recent study used the lawns at Ministry of Justice prison and court sites.   Each site contained four patches,  A patch mown as normal every two weeks - the control  A patch mown every 4 weeks A patch mown every 6 weeks A patch mown every 12 weeks Weekly surveys of pollinators and flowering plants were made throughout June to late August. Butterflies, bees, bumblebees, hoverflies and beetles were recorded as pollinators.   The patches that were mowed less frequently (6 and 12 weeks) had many more pollinators [in fact 170% higher than the 2 week patch], and more flowers.  The most common plants recorded included selfheal, daisy, dandelion, creeping buttercup, and white clover.  Apart from the increase in biodiversity, the patches were ‘visually pleasant’, contributing to the wellbeing of staff / prisoners and saved on lawnmower fuel (cost). Details of the study : https://conservationevidencejournal.com/reference/pdf/12801 Farms and Pollinators. Farms and their crops, such as clover and oil seed rape, can offer a rich supply of pollen and nectar to pollinators.    The ‘richness’ of this supply can draw pollinators away from more natural areas.  However, the pollinators can go from ‘feast to famine’, when the crop has finished flowering.   A Swedish study has followed the behaviour of farmland pollinators after clover flowering.  They found that if natural areas were available after the flowering of the clover, then pollinators [like different bumble bee species] became more selective in their foraging.  This reduces the intensity of competition between the various pollinator species.  Areas of natural vegetation on farmland are therefore important in helping pollinators adapt after crops (such as clover) have finished flowering. [caption id="attachment_33904" align="aligncenter" width="650"] Oilseed rape[/caption] https://www.sciencedirect.com/science/article/pii/S0167880924005735?via=ihub Gardens and pollinators. A study In the Boston area of the US has revealed that small gardens with a diverse range of plants are important to pollinators.  The researchers first used Google Street View to identify and categorise some 86,000 front gardens (or yards, in their terminology) across the area - ranging from lawns to diverse flower gardens. They then visited 500+ of these gardens when the plants were flowering [in 2021], identifying and documenting the plants in each.   The found that : Whilst the higher income areas tended to have more cultivated flower gardens, these gardens were home fewer wild flower (weed) species. Small gardens often had the richest diversity of plants in flower as compared to those with lawns. The authors of the study conclude “Dense urban areas are a promising target for pollinator conservation.” Detail of this study can be found here : https://www.sciencedirect.com/science/article/abs/pii/S0169204624002706?via=ihub