“The perfect spot for sunbathing, in a peaceful woodland edge location, offers privacy and safety in which to relax or indulge in some leisurely
grooming preening. No charge for use of facilities”.
This summer this ideal location, set conveniently for me just a few metres from my kitchen and bedroom windows, has been a popular spot with some of the local birds, particularly some of the younger ones.They come to make the most of this sheltered sun-trap to sunbathe, also known as ‘sunning’ in application to birds. Sunning birds may become so absorbed in the activity that they are easily approached, which can make them vulnerable to predators. They are safer here; there is no easy access to this spot from any angle, although a savvy Sparrowhawk may possibly be able to make a strike if it got its timing right so as not to cast a shadow.
Most commonly we see Blackbirds and sometimes Robins sunning in gardens , but other species indulge too in slightly different ways.
To begin sunning, birds orient themselves to expose the maximum amount of their plumage to the sun. The classic sunning posture is thus: head and body feathers are fluffed up and out and depending on available space and/or sense of security felt, one or both wings are held out from the body with feathers spread; the tail is sometimes fanned out too. The bird may keep the same position throughout a sunning session, or it may change positions to expose different parts of its body to the sun.
Sunning is often a precursor to preening, vital to a bird’s feather maintenance, and in this instance it is thought this has two effects; one is that the sun’s heat helps to spread preening oil across the feathers. The other is that it drives out parasites from within the plumage that can then be more easily dislodged as the bird preens.
Sunning and Preening demonstrated by a Dunnock
I’m fairly sure this session was more concerned with pest control than anything else.
Firstly, adopt the sunning pose: fluff out feathers and spread tail and wing feathers. Well, alright just the tail feathers will do for now.
Secondly, begin preening with any particularly itchy spots caused by unwelcome hitchhikers.
Pay attention to armpits
Some areas such as the head and around the eyes and bill can only be serviced by extending and lifting the leg and having a good old scratch.
It helps to have a flexible neck.
That will have to do for now, it’s getting a bit shady here.Time to go.
The young Robin in the following sequence of images seems to be similarly afflicted with ‘lumps’ apparent on its neck.
The head and neck are areas birds are unable to reach with their bills and have to scratch with a foot.
The other side needs attention too.
It looks as though the bird’s frantic scratching has created a bald spot. And is that another lump under its eye?
During sunning sessions birds often have their bills open. This is because the warmth of the sun raises their body temperature and as they can’t release heat by perspiration, they have to regulate it some other way, so will gape and sometimes pant in order to lose heat.
To sum up, no-one knows for certain the reasons birds sunbathe, although several theories have been proposed.
- To maintain the bird’s feathers in good condition. Exactly how sunning assists with this is not known, despite being widely studied. All birds have a gland on the rump, called an oil gland. The ‘preen-oil’ that this gland produces helps to keep the feathers flexible and hygienic. As preening usually occurs directly after sunning, it has been suggested that the sun affects the preen-oil in the feathers in some beneficial manner, or that it helps to synthesize the Vitamin D and helping to regulate it’s temperature.
- The heat from the sun may stimulate activity in parasites within the feathers, making them more accessible when the bird starts to preen.
- Birds also make use of the sun’s heat to increase their body temperature or prevent heat loss. This form of ‘sunning’ is also used when the bird dries itself after bathing.
- They do it simply because they enjoy it.