No fruit bats, no durian fruit

This video says about itself:

14 May 2015

A Cave Nectar Bat is pollinating durian flowers in Thailand. The durian is the king of South East Asian fruits, selling for billions of dollars annually. However, every flower must be pollinated by a bat in order to set fruit, even when grown in orchards.

From the University of Nottingham in England:

Durian industry could suffer without the endangered fruit bat

October 3, 2017

Scientists have discovered that Southeast Asia’s endangered fruit bats — commonly known as flying foxes — play an important part in the pollination of the iconic and economically important durian tree.

Using camera traps, researchers collected video evidence showing the island flying fox (Pteropus hypomelanus) pollinating durian flowers, leading to the production of healthy durian fruit. Their study — Pollination by the locally endangered island flying fox (Pteropus hypomelanus) enhances fruit production of the economically important durian (Durio zibethinus) — has been published in the Journal of Ecology and Evolution.

The video footage was captured on Tioman Island by a team led by Dr Sheema Abdul Aziz as part of her PhD at the Muséum National d’Histoire Naturelle (France) in collaboration with the University of Nottingham Malaysia Campus. Dr Sheema said: “These are very important findings because they shed more light on the crucial ecosystem services provided by flying foxes. Previously it was known that the smaller, nectar-feeding bats are pollinators for durian — but many people believed that flying foxes were too large and destructive to play such a role. Our study shows the exact opposite: that these giant fruit bats are actually very effective in pollinating durian trees.”

The spikey tropical durian fruit, with its spikey skin and distinctive odour, is highly prized throughout Malaysia and Thailand. A ubiquitous icon of Southeast Asian culture, it is also a lucrative industry, generating millions of US dollars in local and international trade. The new findings suggest these economic profits owe a huge debt to large fruit bats such as flying foxes — as they were previously believed to be destructive rather than beneficial.

Dr Ahimsa Campos-Arceiz, from the School of Environment and Geographical Sciences of the University of Nottingham Malaysia Campus and one of the coauthors of the study, said: “The durian is a fascinating plant that, with its flowers pollinated by bats and its seeds dispersed by large animals like elephants, beautifully exemplifies the importance of plant animal interactions. The durian fruit is particularly famous for its pungent smell and unique taste, adored by most people in Southeast Asia and so often misunderstood — abhorred? — by westerners. We hope this study brings attention to the urgency of conserving flying foxes in Southeast Asia.”

Flying fox populations in severe decline

The island flying fox is already classified as ‘endangered’ on Malaysia’s National Red List.

Large fruit bats of the genus Pteropus are severely threatened by hunting and deforestation. They are often sold and eaten as exotic meat due to an unsubstantiated belief that consuming them can help cure asthma and other respiratory problems. They are also persecuted and killed as agricultural pests, as some people claim that the bats cause damage and economic loss by feeding on cultivated fruits.

Consequently, these factors have led to a severe decline in flying fox populations worldwide.

Repercussions for tropical ecosystems

This study shows that these bats play important roles as seed dispersers and pollinators in rainforests, especially on islands. Their disappearance could therefore have repercussions for tropical ecosystems.

This international team of researchers from Malaysia, France, India, and Thailand, in collaboration with Tree Climbers Malaysia, has found that Southeast Asia’s durian supply could be affected too.

Dr Sheema said: “If people end up hunting flying foxes to extinction, it’s not hard to see that there could be serious implications for Southeast Asia’s beloved ‘King of Fruits‘”.


Dutch birds and bats, good news

This 2012 video is called Birds of Holland in the Spring – PIJNACKER – The Netherlands.

Translated from Dutch NOS TV today:

Five Dutch North Brabant province municipalities have committed to conservation of birds and bats. Breda, Den Bosch, Eindhoven, Helmond and Tilburg have agreed with BirdLife in the Netherlands, among other things, to increase the number of nesting places.

This video says about itself:

29 September 2016

Beautiful footage of beautiful mammals, all eighteen species of British bat are featured.

Bat brain signals illuminate navigation in the dark. With new tech, researchers track nerve cell activity as bats dodge and weave. By Amber Dance, 12:30pm, September 20, 2017.

Rare pond bats research

This 23 June 2017 Dutch video shows pond bats, rare in the Netherlands, being freed by biologist Anne-Jifke Haarsma after transmitters have been affixed to their backs for research.

Red light does not harm bats

This video from Texas, USA says about itself:

Austin Bats under Capital Bridge HD with a red light

Filmed in April of 2012 on a Canon HD DSLR

From the Netherlands Institute of Ecology (NIOO-KNAW):

Red light has no effect on bat activity

Changing the colour of artificial light could reduce disruption


Artificial light at night can have a disruptive effect on bats, but not if the light is red. Switching to red light may therefore limit or prevent habitat loss for rare, light-shy bat species. The latest issue of Proceedings of the Royal Society B publishes results from five years of pioneering research led by the Netherlands Institute of Ecology (NIOO-KNAW).

It’s the first time researchers have succeeded in measuring the effects of light with different spectra on the activity of slow-flying, light-shy bats in their foraging habitat. “We’ve found these bats to be equally active in red light and in darkness”, says principal researcher Kamiel Spoelstra. “White and green light, on the other hand, substantially reduce the bats’ level of activity.”

The effect of red light on more common bat species such as the pipistrelle is reduced as well. While there’s a strong increase in activity of this species in white and green light, activity in red light is comparable to that in darkness. This is caused by the strong attraction of insects to white and green (not red) light. Pipistrelles opportunistically feed on these accumulated insects.

Real-life conditions

“The lack of effect of red light on both the rarer, light-shy species and the more common non-light-shy bats”, concludes Spoelstra, “opens up possibilities for limiting the disruption caused by external, artificial lighting in natural areas, in situations where having light is considered desirable.”

One of the things that make this research unique is that the intensity of the light used for the experiments holds up under real-life conditions. “In fact, it’s entirely suitable for use on country roads.” The scale and duration of the experiments also make them quite unique.

Bats hunt for insects at night because there’s not much competition from other animals, and predators won’t see them because it’s too dark. Which is why artificial light can cause such disruption: less common, slow-flying species such as Natterer’s bat or the brown long-eared bat may feel vulnerable to visual predators such as owls.

Agile flyers such as the pipistrelle, on the other hand, don’t mind the extra light. On the contrary: streetlights come in handy for them for catching more insects. Larger bat species such as the serotine bat and the lesser noctule, finally, fly high and don’t seem to care either way.

Control row

“So for the more common species”, says Spoelstra, “artificial light can serve as a facilitator while less common species face potential loss of habitat.” Together with fellow scientists from NIOO and Wageningen University … he tried to find out if adjusting the colour of the light could limit or prevent this effect.

Over a five-year period, the researchers studied bat activity under experimental white, green and red LED-light conditions. For this, they used the one-of-a-kind facilities of the ‘Licht op Natuur’ (“light on nature”) project: eight study sites along forest edges in dark parts of the Netherlands. Each study site consists of four rows of streetlights in a single colour, and a control row of unlit streetlights.

The Licht op Natuur project isn’t ‘just’ about bats, however. The study sites are used to measure the effects of artificial light on a wide range of species including mice, larger mammals, plants, moths, soil animals and birds.

Some of the main partners in the project are Natuurmonumenten (the Netherlands Society for Nature Conservation), Staatsbosbeheer (State Forestry Commission), … the Drentse Landschap Foundation and the municipality of Ede. Data are compiled with support from the main Dutch non-governmental data managing organisations (PGOs). …

The research team expects to issue comprehensive advice – based on the response of all species groups studied – on the use of artificial light by the end of this year.

Rare barbastelle bats back in the Netherlands

This is a German language video about a barbastelle bat.

Dutch Vroege Vogels radio reported on 11 May 2007 about barbastelle bats. They used to be rare in the Netherlands. Until 1993, they hibernated in one spot: a ruin in Zeeuws-Vlaanderen region in Zeeland province.

After that ruin was demolished, the bats disappeared.

On 1 May this year, barbastelle bats were seen again in a woodland in Zeeuws-Vlaanderen.

Japanese bats in winter, video

This video says about itself:

Searching for Japanese Bats – Japan‘s Northern Wilderness – BBC Earth

Steve heads for the Rimizu limestone caves in Japan to search for hibernating bats.