A couple weeks ago, I was walking around in my family’s prairie and spotted this tiny silhouette. The morning sun was shining through the leaves of a stiff goldenrod plant and a fly was (apparently) warming itself in those rays. Since I was on the opposite side of the leaf from the fly, I was able to sneak up, get my tripod set up, and take a couple photographs before it flew off.
The silhouette of a fly on a stiff goldenrod leaf. Helzer Family Prairie, Stockham, Nebraska.
Sometimes danger is waiting just around the corner…
An ant explores an annual sunflower for extra-floral nectar, seemingly unware of the crab spider lurking on the other side of the petals. The Nature Conservancy’s Niobrara Valley Preserve – Nebraska.
Last summer, I wrote a post about annual sunflowers, including a short bit about how sunflowers secrete extra-floral nectar to attract ants. The ants eat the sweet substance and may help repel potential herbivores from the sunflower in return. As you might expect, however, an abundance of ants can also be a potential source of food for other predators – including crab spiders. When I was at our Niobrara Valley Preserve last week, I noticed several instances where crab spiders were hanging around on sunflowers. They probably weren’t waiting specifically for ants, but apparently ants are an acceptable prey item if they happen to be available (see below).
A crab spider feeds on an ant it caught on an annual sunflower. This photo was taken a few minutes after the above photo, but it wasn’t the same sunflower, spider, or ant shown in that first photo.