Guernsey residents have been asked to help birds through the winter after the especially cold weather.
The Environment Department and La Societe Guernesiaise said dogs have to be kept under control and not allowed near birds on beaches.
They said: "Wading birds and sea birds expend a lot of energy in very cold weather while they hunt for food.
"Those birds which don't find enough food during low tides may not survive the night in very cold weather."
Environment Minister Peter Sirett said: "This second spell of very cold weather will mean that garden and sea birds will be struggling to maintain their fat reserves, which are essential if they're to survive the rest of the winter.
"Feeding birds in the garden is second nature for many people here, but right now this may be all that's keeping them alive."
He said dog walkers should especially avoid the beaches at Richmond and Vazon as they are home to various species of wading birds, which have very few hours of daylight to feed at this time of year.
Deputy Sirett said: "Giving birds some care and consideration during the worst of the winter weather will help maintain the island's natural biodiversity for the future."
La Societe said access to fresh water was essential all year round and frozen bird baths should be gently thawed out with warm water each morning.
The group said it was important to put out the right foods as "it may be the difference between life and death for some species" as "small birds such as Blue Tits need to eat a quarter of their body weight every day in cold weather".
It said food put on the ground should be placed away from bushes to avoid birds being ambushed by cats and any uneaten food should be cleared daily to avoid attracting vermin.
One type of food it advised to avoid putting out during the winter was bread as it "has no food value and by filling them up it prevents birds looking for the nutritious foods they need through the cold weather".
La Societe said scraps such as fruit cake, jacket or roast potatoes, grated cheese, suet or scraps of raw pastry were all welcomed by hungry birds seeking fats and protein for energy.