Tree Swallow (Tachycineta bicolor)
The tree swallow breeds in natural or artificial cavities, which is the reason why they gladly move into suitable nesting boxes provided by humans and nests made by other birds. The nest itself consists of multiple layers of twigs and grass to which a lining of feathers is added. These feathers are not plugged from the own coat but rather collected and often originate from many different species. The tree swallow often builds its nest close to water.
Tree swallows brood only once in a year, with only the female sitting on the four to seven white eggs. The young ones will be fledged after 16-24 days.
My Lungs *
If you ever climb the stairs of a church tower, you quickly get "out of breath". You breathe much faster than normal. Of course, with us it's a little different. At rest, I breathe something like 26 times a minute. While flying, it goes up to 490 ! You can well imagine that a normal lung system wouldn’t be able to handle the strain. So our Creator figured out something quite unusual for us.When I fly, my lungs are supported by a whole row of bellows. These are air sacks of various sizes, that are not only connected to my lungs, but also to certain hollow areas in my bones. The constant contraction and relaxation of my flight muscles cause these air sacks to be compressed and expanded at the same rate. They are filled by air pressure coming from the slip stream as I fly. Through this special construction, my lungs are ventilated twice each time I breathe (by inhalation, and expansion of the air sacks). In addition, these air sacks serve as a cooling system for my highly stressed muscle system, and as padding for my inner organs. All of this is absolutely necessary, otherwise, our organs would be thrown to and fro by our constant acceleration and braking manoeuvres, and we would have to vomit. **
** translation of this clause corrected based on original language text
The swallow continues: My Nest
* quotes from the book "If Animals Could Talk"
