Why swans could also be extra more likely to die from hen flu

The south of England is not any stranger to hen flu scares, with outbreaks amongst poultry affecting the livelihood of farmers in Hampshire and Dorset.

Now suspected cases among swans are reported to be on the rise, most not too long ago throughout Berkshire, the place about 30 swans died on the River Kennet in Newbury, together with about 12 on the River Thames in Windsor, two in Maidenhead and an additional two discovered downstream.

Dr Teresa Frost, head of waterbird monitoring at British Trust for Ornithology (BTO), says there appears to be “genuine susceptibility” to the illness among the many swan species, as a result of life-style and climate components.

There are multiple signs of the highly pathogenic avian influenza (HPAI) in contaminated birds, together with a swollen head, closed and runny eyes and disorientation.

Frost says they’re “feeling generally unwell, just like we would”.

“They can be very listless and not doing their normal behaviours, sometimes they can also preen more than usual.”

She says individuals are “more likely to see dead swans than they are to see a bird that’s more well camouflaged”.

“But I think even despite that, there does seem to be genuine susceptibility and we are seeing at times large numbers of deaths in different places,” she provides.

“It’s not confined to just Southern England, for example we’re seeing similar reports from Scotland.”

Frost observes some hen species “seem to be more susceptible than others”.

“We’re still a bit unsure about how much of that is due to genetic differences or just the way that the birds are.

“But what does appear to be very clear is that wild fowl, like geese and geese and swans, appear very inclined.”

She adds that with water birds, “it is also the atmosphere that they dwell in and the way in which they behave”.

Frost says that while the flu “may be destroyed by daylight and heat”, during the winter “it might fairly fortunately keep inside nonetheless water for fairly lengthy durations of time”.

“If you’ve got obtained a hen species that normally lives in that form of atmosphere, then clearly they’ll be extra more likely to be uncovered to the virus,” she says.

She adds that in winter, water birds tend to congregate in certain places, “so that they’ll clearly have the ability to host the virus and transmit the virus to one another”.

“And additionally from not solely inside their species, but additionally between species – you may get one species that maybe is just not that badly affected by it, [which] then may convey that virus to a species that’s extra inclined to mortality and you then see deaths occurring in that different hen species.”

The mute swan is among the most recognisable species, but Frost also mentions the migratory wild swans Whooper and Bewick’s swan populations.

“In Whooper swans specifically, early within the season this 12 months, we did see some large mortality occasions and we predict that, a bit just like the mute swans, this was partly as a result of they have been all roosting collectively.

“[They form] these tight groups of individuals all close together and that was caused we think by weather conditions at the time – there wasn’t as much places for them to roost so they were having to be more concentrated.”

Frost says the case appears to be “a bit more random” with mute swans.

“You’ll get it in one lake now and then you might see nothing but then in another town, in a couple of months time, you’ll get a similar thing happening.

“It’s very distressing for the people who find themselves going there day-after-day and seeing the swans get sick sooner or later after the opposite and die very often.”

A current case of suspected hen flu within the South closed Abbotsbury Swannery in Dorset per week sooner than deliberate.

Frost says the BTO has been doing work on the disease’s impacts on wild birds.

“Thinking in regards to the conservation implications is without doubt one of the issues that we’re engaged on.”

She adds that they are collaborating with the Animal and Plant Health Agency (APHA) to “have a look at spatially which areas of the nation you may anticipate extra virus to be in”.

“This issues as a result of we predict that there’s a sturdy hyperlink between the variety of water birds and the quantity of virus within the atmosphere and that has an influence then on the agricultural atmosphere and poultry.”