Blue Tits Are Also Coping With an Epidemic
We are not the only ones advised ‘social distancing’…
The blue tit is a common garden bird characterized by its lively blue and yellow colored feathers. Sadly, in Germany, Belgium, and Holland, many blue tits have been reported sick or dead this season. While humanity is fighting a viral infection, these birds are fighting a bacterial one. Which bacterium is the culprit, what are the disease symptoms, and is there something to do against this epidemic?
Feathered Friend
Everyone is familiar with the great tit (Parus major), one of the most common visitors of European gardens. Less people know the blue tit (Cyanistes caeruleus), a close family member. This species is somewhat smaller (12 vs. 14 cm in length, on average) and displays cheerful blue feathers in addition to the yellow and black plumage. The bird enjoys a varying diet comprised of insects, caterpillars, and seeds, dependent on the season. Although blue tits are more shy and less abundant than great tits, they can still be spotted year round in Europe.
Disease and Death
The NABU, a German conservation group, first became aware of a possible disease outbreak back in March 2020. More blue tits than usual were found dead or sick. This prompted both biologists and scientists to do more research, of which results were not received before late April. In many investigated cases, the same bacterial infection was found. Currently (in May), already around 11,000 sick and dead blue tit cases have been reported in Germany this year. Actually, this specific infection is not a new trend; already since the 1990s, blue tits in the UK have been fighting contamination of this disease in separate epidemic waves.
Symptoms and Susceptibility
The cases examined were affected by the bacterium Suttonella ornithocola, a member of the family Cardiobacteriaceae. This family is known for their rod-shaped appearance and 1 to 5 micrometer length. Although these pathogens are small in nature, impact on their hosts can be massive. They affect the lungs, presumably in a similar way to pneumonia, and consequently lead to breathing difficulties. Apart from breathing more heavily, birds show several other symptoms when infected. Blue tits are less shy when approached, and no longer eat food that is handed out to them.
Tit-To-Tit Transmission
Since many sick or killed birds are found near feeders, Suttonella ornithocola is thought to be airborne and thus transmitted when birds congregate. Several other infectious diseases caused by bacteria, such as Chlamydia, can be transmitted from birds to humans or other animals. This bacterium also affects other tits (although less) such as the great tit, long-tailed tit and coal tit. However, the disease has not been reported in any other species apart from these four closely related birds, so all other organisms seem to be either insusceptible or immune. So far, the disease has only spread from Germany to Holland and Belgium. Transmission to new countries is expected to be quite slow. Although this specific bacterial infection has previously been reported several times in the UK, a biologist in London said no increase in blue tit mortality has been seen there so far. Nonetheless, the bird populations overseas will be closely monitored.
Advice and Action
We can only guess the length of the infectious period and the pace at which this epidemic wave will fade. In the mean time, some measures can be taken to minimize damage. First of all, the public plays an important role in supervising, since the UK urges its citizens to report dead or sick blue tits they encounter. It is also suggested to stop placing drinking and feeding troughs. Gatherings of blue tits around these increase transmission risk through aerosols. The birds themselves, in the mean time, are advised to ‘practice social distancing’, as stated earlier by The Independent.
Prosperity Practices
The blue tit has just been classified as increasing on the IUCN Red List of threatened species. To keep this trend up, they should stay away from close contact. As is the case for us humans, meeting fewer friends and family members reduces transmission risk. Let’s hope both the viral infection in humans and the bacterial one in blue tits will be conquered soon.
Articles used in the process of writing:
- https://www.dw.com/en/mystery-disease-killing-germanys-blue-tits/a-53198113
- https://www.independent.co.uk/environment/blue-tits-birds-social-distancing-disease-germany-nabu-lower-saxony-a9478896.html
- https://www.theguardian.com/environment/2020/apr/22/mystery-bird-illness-investigated-after-german-blue-tit-deaths
- https://www.gardenwildlifehealth.org/portfolio/suttonella-ornithocola-infection-in-garden-birds/
Stay updated for the role of badgers in SARS-CoV-2 transmission!
Thanks for reading! I hope you like my blog. I am Mo Schouten, a Biology student located in the Netherlands. Capturing my environment with a camera is what I love most. — — Comments as well as tips are always welcome; leave them below!
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