can bird houses get too hot

He is still out there, perched on top of the bird box, standing guard over the little ones snuggled up in the messy nest within. The female house wren tends to them. There will be a change of guard at some point.

For the past month, every time we drive in or out of out driveway, a little tannish-gray head pokes out of the bird box hole to see what all the commotion is about. Curious, I peeked in and found several baby birds with fluffy feathers inside. It occurred to me that they must be pretty hot in there, all bunched together inside a box. Granted it has air slits around the top, but with as many as 8 young in the box, it must get pretty warm.

Birds have a normal temperature of 105 degrees Farenheit, warmer than mammals. All passerines (perching birds), have a high rate of metabolism and a byproduct of this is heat. During flight, the wing muscles also generate heat. This heat needs to dissipate in some way to maintain 105 degrees. But the catch is that birds do, not possess sweat glands like we do so they have to rely on other means for cooling themselves down.

According to Cornell Lab of Ornithology, the optimal range for bird egg development is 96.8 to 104.9 degrees. If egg temperatures are lower, embryonic development is slow, and if the temperature is too high, it can be lethal. High temperatures can also be dangerous for nestlings, which can quickly become dehydrated. For example, Bluebird eggs and nestlings cannot survive temperatures exceeding 107 degrees.

In summer, temperatures inside a nest box can reach 120 degrees, and are often at least 10 degrees higher than the outside temperature. Nestlings younger than nine days old often die from heat stress or dehydration. If you are curious about the temperature inside a particular nest box, you can use a high/low thermometer during full sun and place it in your nest box for a few minutes to see if it hits 107 degrees.

Nest box color can also play a role in temperatures inside a box. It is best not to paint or stain boxes dark colors, since they will absorb heat. In hot climates, boxes should be placed where they are shaded from the afternoon sun. Providing ventilation slits in the upper half of nest boxes allows access heat to escape. Slits work better than small round holes and many bird box designs include them.

To provide shade, some folks have rigged umbrellas over the box to keep the hot sun from hitting it directly. There are also designs for making a second roof over the top of bird boxes, using either wood or garden cloth. This second roof should be positioned a few inches above the bird box roof to allow air to pass through. We are lucky that our little wren family’s box is shaded for much of the day so the box doesn’t get too hot.

Birds have a variety of ways to beat the heat. Much of the excess heat escapes through bare skin on the legs and feet, brood patches, (bare skin that is held against eggs and young), and through the skin under the feathers. Another way birds cool off is by “panting.” By using their unique respiratory system, birds can reduce heat through evaporation from inside their bodies. Birds appear to “pant” by fluttering their neck muscles and taking in air which cools the inside of the mouth, tongue, throat and respiratory tract. This helps increase airflow and oxygen levels while simultaneously allowing water to evaporate off the tongue. Birds have a pair of lungs that do not expand like mammals. However, in addition to the lungs, birds have several air sacs, allowing them the ability to store more air that aids in respiration during flight.

Some species, such as pelicans, cormorants, owls, pigeons, pheasants, quail and a few others, have a gular (gew-lar) pouch. The gular is a patch of skin located on the upper throat by the chin that can be vibrated to help cool them down. Another option for cooling is to soar higher, where the air is cooler. This includes raptors. Shore birds will stand in the water and one weird practice among vultures is to pee on their legs. As the urine evaporates it cools the bird’s legs. If all of these mechanisms fail to cool birds down, they reduce their activity and seek shaded areas. They are also more active at dawn and early evening.

We can help turn down the heat by providing shady areas and providing water. Smaller birds lose more water during the cooling “panting” process and so need access to water supplies. Granted we have had enough water this summer, but after it has seeped into the ground or has evaporated to contribute to our already high humidity, it is unusable to birds. Providing them with fresh water in bird baths can help. During really hot weather, birds seek the comfort of water and bathe more often to keep cool.

On very hot days I have watched mourning doves, robins, cardinals and many other birds nestle down and soak in water with their wings outstretched, sometimes for several minutes, letting the cool water wash away the heat. A simple bird bath can be made by using an upturned trash can lid. Add a few stones so the birds can judge the depth.

Our birds are fond of a bird bath located in our shade garden where the water is cooler. Birds are also naturally attracted to moving water, so man-made creeks, fountains and water wigglers invite them to bathe. Last summer, my dad was watering his garden with his thumb over the end of the hose. Much to his surprise, a hummingbird started flying to and fro through the mist. He was delighted.

Keeping birds baths filled with clean cool water is essential. It is also a good idea to change it every few days to keep mosquito larvae from developing. Sprinkling a few Mosquito Bits (a biological mosquito control) into standing water which is safe for wildlife and works very well.

For now, our little wren family is doing well, they will be flying around soon. Their parents no doubt, in addition to teaching them what to eat, will be showing them where all the best water sources are.

The same method can be applied to the sides for attaching aluminum reflective panels. Trim aluminum sheets to the appropriate side lengths, insert four 1/2-inch spacers on each side to provide ventilation, and fasten with four 1 to 1 5? screws.

According to Cornell, the optimal range for bird egg development is 96.8 °F to 104.9 °F (36 °C to 40.5 °C). If egg temperatures are lower, embryonic development slows. Higher temperatures can be lethal for the embryo. (Birdscope, Summer 2002, Vol.16 No.3, Cooper and Chu). Bluebird eggs and nestlings cannot survive temperatures exceeding 107 °F (41° C) (Conley Black). Prolonged excessive heat can severely impact nestling health due to dehydration and heat stress.

The Missouri Bluebird Society recommends an air gap of at least 1/4? inch between the first and second roofs. Spacers (for insulating airflow through the two roofs) can be made of washers, machine nuts, strips of wood, etc. Just attached an oversized roof to the existing roof with screws inserted through the wood from the top, through spacers, and into the existing roof. (This might take more than two hands!).

Babies hatched: S. In the original heat-shielded box, Harris has had a pair of EABL nests and laid a clutch of four eggs. On July 4, three of the eggs hatched, and on July 7, the infertile egg was removed. The temperature inside the heat-shielded homes has never increased by even a single degree above the outside air temperature as of 7/22/03. In the nestbox, it was 104 degrees on a day that was 106 degrees.

Irving Berlin, “Blue Skies,” 1927; “Blue skies smiling at me Nothing but blue skies Do I see Bluebirds Singing a song Nothing but bluebirds All day long”

A gular (gew-lar) pouch is possessed by a few species, including pheasants, quail, owls, pelicans, cormorants, pigeons, and others. The gular, a vibrating skin patch on the upper throat near the chin, is used to help people feel cooler. A different way to cool off is to ascend higher, where the air is colder. This includes raptors. Shorebirds will stand in the water, and vultures have an odd habit of urinating on their legs. As the urine evaporates it cools the bird’s legs. Birds will become less active and seek out shaded areas if none of these mechanisms are able to keep them cool. They are also more active at dawn and early evening.

Some people have rigged umbrellas over the box to provide shade and prevent the hot sun from directly hitting it. Additionally, there are plans for adding a second roof to bird boxes using garden cloth or wood. To allow air to flow through, this second roof needs to be placed a few inches above the bird box roof. Fortunately, our little wren family’s box is shaded for a good portion of the day, keeping it from becoming too hot.

Keeping birds baths filled with clean cool water is essential. Changing it every few days is also a good idea to prevent the development of mosquito larvae. Adding a small amount of mosquito bites—a biological mosquito deterrent that is both safe for wildlife and highly effective—to standing water

A bird bath in our shade garden, where the water is colder, is a favorite spot for our birds. Because they are drawn to flowing water by nature, man-made creeks, fountains, and water wigglers encourage birds to take a dip. My dad was using the hose to water his garden last summer, and he was holding his thumb over the end. To his astonishment, a hummingbird began circling through the mist. He was delighted.

We have a healthy little wren family for the time being, and they will soon be soaring. Their parents will undoubtedly teach their children where all the best water sources are in addition to teaching them what to eat.


How do you cool down a birdhouse?

Add Extra Vents to Bird Houses Add extra vent holes to the house to be sure the circulation is adequate on hot summer days, and check that the holes have not become blocked with nesting material or debris.

Can a birdhouse get too hot?

Yes, baby birds can get too hot. Birdhouses exposed to scorching sunlight and sweltering temperatures can cause baby birds to overheat and stress.

Can you put a birdhouse in full sun?

Unless there are buildings or trees to provide shade during the day, face your bird house between north and east. This will avoid direct sunlight and the wettest winds and should also provide optimum light for your bird house camera.

What temperature is too hot for bird eggs?

Temperature and humidity during storage Fertile eggs should be stored between 55 and 65°F. If fertile eggs reach temperatures above 72°F, embryos will begin to develop abnormally, weaken, and die.