Summer's over! For humans, that means the end of BBQ season and the start of searching for your favourite woolly scarf.
But if you're a bird, northern Europe might be losing its appeal in a much more important way, and it's time to get out before all your food disappears.
Bird migration is pretty amazing. A range of species, from swallows, robins and house martins to hobbies, some warblers, ducks and ospreys do it, because life is easier elsewhere (you can see how Loch Garten's ospreys are getting on our website). But although it's normal behaviour, it's never easy.
How do they do it?
We still don't know exactly how birds find their way to places they've never been to, or what tells them to leave. They might navigate using the stars, smells or the earth's magnetic field. There's still so much we don't know.
Whatever triggers that urge, it means leaving an area you're familiar with, and very likely crossing difficult terrain.
For example, as a warbler like a whitethroat, plenty of insects await you once you arrive in tropical Africa. But to get there you first have to cross the sea (definitely the Channel, maybe the mighty Bay of Biscay and then the Mediterranean), and finally the ever-widening Sahara desert!
Migration is tiring, especially if you have to keep going for a long time, and it's not always easy to stop to feed along the way.
Birds like swallows have it fairly easy, as their small insect prey can be grabbed and eaten as they fly along. Others, like the warblers, often fatten up before they start their journeys. Fat is fuel for migration, and it's stored under the bird's skin (if you saw a bird without its feathers, the fat would look like smears of butter around the pink muscles).
Birds need to balance the advantages of being fat (and having plenty of fuel in reserve) with that extra weight making them less manoeuvrable - and maybe more prone to being caught by a predator. Swallows stay lean and mean, but warblers like blackcaps can put on an extra 25 per cent on top of their pre-migration body weight!
How you can help
We know that lots of our migrating birds that cross the Sahara are in trouble. Populations of some have declined by 93 per cent in the last 40 years, and finding out where their problems lie is difficult. But we're working on it, in the UK, Europe and Africa. Make a donation and you can give migrant birds a helping hand.
You can do your bit at home, too.
The easiest way to help birds in your garden is to grow insect-friendly plants, or shrubs and trees that produce berries.
One of the best is honeysuckle - it's evergreen, providing shelter for wildlife all year-round, it has flowers which smell gorgeous and which bees, moths and other insects love, and then you see a crop of beautiful, shiny red berries at this time of year, which warblers and other birds can't get enough of!
There are lots of other great plants for garden wildlife to choose from - sign up for Giving Nature a Home and you can get loads of advice and tips for free.
Thank you so much Katie for the link ! I've had a good read .