Thyroid-Stimulating Hormone (TSH). Guide. A thyroid-stimulating hormone (TSH) blood test is used to check for thyroid gland problems. TSH is produced when the hypothalamus releases a substance called thyrotropin-releasing hormone (TRH). TRH then triggers the pituitary gland to release TSH.
A Raven is black but depending on which way the light hits it they change to other colors like bluish, dark red, or greenish. There are white Ravens but are not albino.
The colour of Speculum feathers is one method where the duck species can be identified from ; Common Teal and Green-winged Teal : Iridescent green edged with buff , Blue-winged Teal : Iridescent green , Crested Duck and Bronze-winged Duck : Iridescent purple-bronze , edged white , Pacific Black Duck : Iridescent green , edged light buff , Mallard : ...