Chirping and vulnerable-looking birds can look like they're calling out for your help, but we humans can quickly do more harm than good in these situations.
Young birds tend not to be as helpless or orphaned as they may seem, which is why German's Nature And Biodiversity Conservation Union (NABU) advises you to stop and intervene only when it makes sense.
Particularly noisy are fledglings that have opened their eyes and have feathers, but have not yet learned to fly. Their parents still feed them insects and use calls to communicate with them.
So how can you tell if these little birds need help?
Watch from a distance for about an hour to see if the parents are still looking after their young. If neither parent appears, you can pick up the bird and care for it. But wear gloves to do so. Don't wait if any of the following applies:
Immediate danger: If the calling bird is on or near a road, or seems easy prey for the likes of a nearby cat, move it into a shelter or hedge.
Nestlings: Nestlings keep their eyes closed and do not have feathers. Adult birds usually keep them warm and feed them constantly. If you find such a baby bird, look for its nest and put it back. If you cannot find the nest, take the bird to the nearest animal shelter.
Injured bird: If the young bird is injured, seek help from a vet, bird rescue centre or animal welfare organization. To carry it, you can place the foundling in a cardboard box lined with kitchen paper with air holes.
Too wet: If the young bird is wet, dry it indoors. Place the bird on a hot water bottle filled with lukewarm water and wrapped in a towel. Be careful not to overheat the bird! If it starts to pant or seems weak, it is too warm.
If you found the bird in this hot state to begin with, take it to a cool, shady place first, say the NABU experts. If the bird still needs help despite all your attempts at first aid, take it to an animal shelter or bird rescue centre.