They also said that not all leftovers are good for the little winged creatures, so they released a list of "do's and don'ts" for feeding Christmas leftovers to birds, The Independent reported.

The list puts Christmas cake and mince pies high on the list of good snacks for birds, since dried fruit and fat are very high energy. Unsalted snacks are supposed to be good for house sparrows, greenfinches, tits, robins and starlings.

The Royal Society for the Protection of Birds told The Independent to make sure that there is water available as well since dehydration is as dangerous to birds at this time of year as starvation.

The society warns against putting out cooked meats as they could attract unwanted vermin.

Salted snacks, like peanuts, bacon and chips are a big "don't," because most garden birds cannot process salt and will die if they ingest too much.