Nectaries on Red Bird of Paradise

The red bird of paradise, Caesalpinia pulcherrima, is a plant with large, attractive red-orange-yellow flowers. It is a popular plant in desert landscapes.

The flowers have long stamens, and is thought to be pollinated by butterflies, especially swallowtails that flutter their wings while feeding.

This flower also has an ant.

Can you see it now?

It’s a rover ant, Brachymyrmex patagonicus. Any ideas what the ant might be doing?

The swollen gaster might be a clue.

Honey bees and wasps exhibit the same behavior.

Here’s another clue.

Apparently these plants have extrafloral nectaries as well as nectaries within the flowers. Isn’t it funny where all these extrafloral nectaries show up on desert-adapted plants?

R. W. Cruden and Sharon M. Hermann-Parker. 1979. Butterfly Pollination of Caesalpinia Pulcherrima, with Observations on a Psychophilous Syndrome. Journal of Ecology. 67( 1): 155-168