Learn how to identify a male and female tree swallow. Find out about their nests, song, range map and ... and more blue-green upperparts. Females, too, will have that blue-green, but it’ll be a ...

Metallic blue tree swallows nest in bird houses or in tree cavities. (Photo by Allan Hack) Our last two notable swallows, the tree swallow and the violet-green swallow, do not build mud nests.

Scientists in Thailand have discovered a new species of tarantula with a very unique blue hue. The tarantula is named Chilobrachys natanicharum and is also called the electric blue tarantula. The ...

Tree swallows are easily identified by their glossy blue-green upperparts, snowy white breast and belly and short forked tail. They have a gently planing flight that’s quite different to that of other ...

Tree swallows are also shiny blue above, including in a dark helmet that scrunches down firmly over their eyes, and clear white below.

Tree swallows, with their iridescent blue backs and clean white undersides, are always a treat to see swooping around, catching aerial insects (another maybe less pleasant sign of spring).