One of my favourite hobbies is to observe the butterflies, birds, squirrels and hedgehogs in my garden.
Here in Austria we have an App where everyone can upload their pictures of butterflies they have seen and this helps Scientists to messure the destribution and the number of butterflies which live here. Every year there is a "competition" where they are looking for one specific butterfly 🦋 - that helps them determine if the population has decreased or increased compared to other years.
Every year in January we have a 3 day "competition" called "Stunde der Wintervögel" ("Hour of the winter birds") 🐦. Austrians are called upon to meet in parks or just observe the birds in their garden and to write down how many birds of differnt species they see at the feeding stations (in the space of one hour). So for example if you see 5 blackbirds at once and thats the highest number - you write down 5 - and so on.
To watch how many hedgehogs live in my garden, I have installed a few wildcams where I have put the feeding stations for my spiky gardenmates 🦔. They make the cutest noises while eating ☺️!
I also have a feeding station for squirrels and I love watching them get a nut and then bury it in the garden - to never find them again, judging by the number of nuttrees growing in my lawn 😂!