Does Temperature Affect Bird Feeding Behaviors?

Heat

• Birds do not sweat, so they need other ways to cool themselves off when temperatures are high. During the middle of the day, when the temperature is the highest, birds will sit in the shade, cool themselves off in water, or puff out their feathers to get rid of the heat. Birds can also gape, which is similar to panting. Foraging for food is usually done earlier or later in the day when the temperature is cooler.

Cold

• Birds that do not migrate south have adapted to deal with cold weather. They have thick layers of down and small feet. They will often tuck their heads close to their body when sleeping and reduce their body temperature at night to reduce energy loss. During the winter, birds need to spend more time foraging for food than in the summer for two reasons: they need more energy to boost their metabolism and food is harder to find. Most birds will spend all day foraging for food.

Extreme Cold

• When temperatures drop below minus 20 degrees Fahrenheit, birds will stop looking for food. Instead, they find shelter and wait for the temperature to warm up, a behavior known as "torpid." This is actually a survival technique, according to wildlife ecologist Margaret Clark Brittingham. Birds would expend more energy trying to stay warm while looking for food than they could find while foraging. Since bird feeders do not require any foraging, bird activity will increase. In cold weather, bird feeders filled with sunflower seeds can double the survival rate of wild birds because it allows them to keep warm without expending energy foraging.

Small versus Large Birds

• You might think that larger birds would eat more when the weather gets cold, but the opposite is true. Ounce for ounce, smaller birds need more food in the winter than larger birds. Smaller birds have a higher metabolic rate and body temperature than larger birds. They also lose heat easier because they have a larger surface area to volume ratio. They need to eat more food to produce enough heat to stay warm.