The beautiful, tropical Allamanda is distributed from Mexico down through Argentina, so it is very likely the hummingbirds have seen this flower before.
It is a woody plant and the one I purchased had a spiky ball in the middle of it. It turns out this is a seed pod which will eventually dry out and split open and release several seeds.
I try to encourage the hummingbirds to come to the flower by setting the plant near the feeders. Maybe it is because they have seen it before and are familiar with it, but it took them some time before they even checked it out.
During the time I have spent at the Patuxent River and also the pond, I have seen hummingbirds working over the orange trumpet vines that are common near water. They have a similar tubular flower.
Even though they frequent our feeders, they still enjoy having something besides artificially sweetened water. I can't emphasize enough not too sweeten the mix too much. The ratio is four parts water to 1 part dissolved sugar. Two cups of water and a half cup sugar is usually enough to fill a common sized feeder. Too sweet a mix can actually kill them.
The Allamanda isn't in a hanging basket so I can't hang it near the feeder. I set it on a small step ladder so that it is at about eye level when I am sitting down. What? You didn't think I was going to stand there waiting, did you?
The trick is to align the plant with the background so it enhances the photo rather than detracting from it. The lovely bokeh (a Japanese word describing the out-of-focus pools of light) are actually leaves on trees at the far edge of the yard reflecting light.
I wish there was a sure fire way to encourage the hummingbirds to visit the Allamanda, but I can't think of any. I am fortunate if one comes in once a day. I keep the plant on the porch and only set it out there when I am sitting there. I would hate to glance out the window when I am not filming and see one working it over. That would not make my day!