Tuesday, 24 October 2017

Some Notes on Asian Hornets

Some Notes on Asian Hornets

According to the Wedderspoon website, one of the reasons we may be seeing more Asian Hornets is because of climate change and habitat loss:

“The Asian Giant Hornets are also experiencing a population decline, although it is not as steady as the decline in bee population. The hornets are facing deforestation in their native areas. Due to habitat loss and climate change, they are forced to move elsewhere such as regions in Europe and neighbours of the Eastern Asia region.”(1)

The website says that there is only one known predator of the species:

“The European Honey Buzzard is the only known predator of Asian Giant Hornets (aside from humans), and they are armed with sting-resistant feathers that protect them from the attacks of their prey. In fact, the feathers have a natural repellant that lessens the risk of being swarmed by the hornets. Unlike other members in the honey buzzard family (including the Barred and Crested honey buzzards), the European Honey Buzzard feeds specifically on the larvae and honey of Asian Giant Hornets. “(1)

Wildlife in France reports that:

“The Honey Buzzard, despite its name, is not related to the true buzzards in the genus Buteo, but is closer to the kites in the genus Perninae. Unlike the Common Buzzard it is a migratory species and spends the winter period from September / October until April in Africa.” (2)

Looking to the Channel Island Bird Website, we find

Honey-buzzard (Pernis apivorus)

Jersey Rare spring and scarce autumn migrant. First recorded 1940, now annual. Guernsey Scarce annual migrant, first record 4/6/1989. Alderney Occasional summer visitor and migrant.

The 2004 review mentioned

“Spring migration is all but over now, with little in the way of new birds this week. Two Honey Buzzards were reported, one over the Zoo on the 11th and the other over Red Houses on the 13th.”

“Another fine day today, with a north-easterly breeze that brought a Honey Buzzard to the Island late this afternoon, picture here flying over Red Houses as it looked for a suitable roost site for the night.”

2017 seems to show more sightings:

“A Honey Buzzard was seen over Les Chenes Farm at Trinity.” (September 2017)

“Despite the wind, there was a little movement at Noirmont with a Honey Buzzard” (September 2017)

“On the east side of the Island, a Honey Buzzard was at La Coupe early on” (September 2017)

“Visible migration at Noirmont staggered along this morning in the fresh wind. The highlights were 3 Honey Buzzards, seen singly and including the juvenile of recent days.” (September 2017)

“There were some more hints of Autumn migration getting underway at Noirmont this morning. An adult Honey Buzzard which flew out from trees there may well have been the unidentified raptor seen there three days earlier.” (August 2017)

“A Honey Buzzard was flying to the West of Sorel around 11 o'clock. Under the usual mob pressure, it headed West along the coast.” (April 2017)

Wildlife in France notes that:

“Honey Buzzard, Pernis apivorus will rip apart perhaps a 100 or more wasp nests during the summer months to feed both themselves and their young with the larvae, and the Bee-eater Merops apiaster will also take large numbers of wasps and hornets among other insects to feed themselves and their young.” (3)

Living Magazine France also notes that:

“There is some hope that they will adapt to preying on the Asian Hornet nests that are increasingly to be seen hanging in the trees throughout the region.”(4)

Nurturing Nature indicates this has promise:

“Recently in France, a honey buzzard was seen attacking and destroying an Asian hornets nest” (5)

It also notes that

“The parasitoid Conops vesiclaris has been shown to parasitise queen Asian hornets in France by French researchers. I have watched Conopid flies as they literally fly towards and slam into flying bumblebee workers and even target them when they have landed on flowers to forage. Job done, egg laid into their host abdomen.” (5)

In conclusion, apart from destroying nests, the best hope for reducing the Asian hornets, especially in remoter locations, is by a predator such as the Honey Buzzard. While the parasitoid Conops vesiclaris flies can destroy hornets they might also attack bumblebees, so care would need to be taken before introducing them into a fragile ecosystem.


(1) https://wedderspoonblog.wordpress.com/2014/01/03/asian-giant-hornets-our-bees/
(2) http://www.wildlifeinfrance.com/honey-buzzard-pernis-apivorus-bondree-apivore-in-france.html
(3) http://wild-life-in-france.blogspot.com/2013/11/poor-year-for-wasps-and-hornets.html
(4) http://www.livingmagazine.fr/sw-france-information/wildlife-poitou-charentes/entry/sw-france-information/wildlife-poitou-charentes.html/honey-buzzard-south-west-france.html
(5) http://nurturing-nature.co.uk/wildlife-garden-videos/asian-hornets-a-threat-to-solitary-bees-or-bumblebees/

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