Black-billed Magpie Nesting Behavior
This past spring and summer I had the opportunity to observe and photograph nesting behaviors of Black-billed Magpies on Antelope Island in northern Utah. Magpies are common in Utah and much of the western US but they’re typically difficult to approach (and very challenging to photograph well because of the contrast of their coal-black and almost pure white plumage) but this pair of birds was so intent on their nest-building activities that they virtually ignored my presence. Mated pair of Black-billed Magpies Magpies are monogamous and typically mate for life. This is a mated pair on top of their domed nest in a sagebrush. The male is on the left, the female on the right – males are about 20% larger than females so they are sexually dimorphic. As you can see from the muddy bill of the female they’ve been actively building the mud-bowl found inside the nest. Typically the male provides the heavier branches and sticks for the nest and the female delivers most of the mud for the mud bowl, which probably explains why the female’s bill is so muddy while the male’s is not. Obtaining mud for then nest The mud for the bowl of the nest was obtained wherever the birds could find it. When we’d had dry weather they would have to fly quite a distance to get any but after a recent rain they would often get it very close by. This bird has just scooped up a bill-full. When it’s available they’ll sometimes use fresh cattle or bison dung in place…