Wednesday, September 21, 2016

Melanistic Hummingbird

Copyright John Cavagnaro

I took a trip to Costa Rica last fall as part of a tropical ecology class. One morning, while hiking through the rainforest, a small group of us saw a very interestingly colored hummingbird; it was completely black. We followed it as it was feeding and I got a few good pictures, but none of us had any idea what species it might be. When we consulted with the other birders in our group, they assured us that there is no all black hummingbird. 




Knowing this, we hypothesized that this hummingbird might have been melanistic. Melanism is the overproduction of melanin, the pigment responsible for black colors in most vertebrates. The most famous example of melanism is the Black Panther; they are not a unique species, but are in fact melanistic Jaguars* (Panthera onca).

Despite the lack of color characteristics, we were determined to identify the species. The shape of the tail and the bill, in conjunction with the species range, allowed us to identify this as a Bronze-tailed Plumeleteer. They are a dark green: dark as far as hummingbirds go, but not this dark.  

Copyright John CavagnaroMy research found very little information about melanism in hummingbirds, but Williamson’s “A Field Guide to Hummingbirds of North America” has a couple relevant notes. The author states that "melanism occurs regularly in a few tropical species," then goes on to describe melanism as "often imparting bronzy or coppery tones to normally green iridescence." You can see this bronzy coloration here, where the bird is perched on a vine.

You can find a few images online of melanism in other hummingbird species, but they generally just appear drab grey and brown. The fact that the normal coloration of the Bronze-tailed Plumeleteer is already quite dark makes melanistic individuals of this species especially striking, with entirely black plumage.

The significance of melanism in tropical species is not yet understood; one theory is that the darker colorations are more difficult to detect in the dark understory of the rainforest. Melanin content may influence feather strength as well as resistance to disease and parasites. In any case, it was very exciting to see this mutation in the wild, and I’m glad I could get a clear shot of this magnificent bird.


*At least in Central/South America. In Africa and Asia, “Black Panthers” are melanistic Leopards (Panthera pardus)

Williamson, S. 2001. A Field Guide to Hummingbirds of North America. Houghton Mifflin Harcourt, Boston.

8 comments:

  1. Hi - this is very interesting. I just returned from Franklin, North Carolina, and my friends have a healthy ruby throated hummingbird population, however one of them is black! i wondered if it could be a melanistic hummingbird. I have seen melanistic hawks, but never a smaller bird.

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  2. I had a black hummingbird at my house this morning in Elmer Louisiana

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  3. Thanks for your post! Searching and searching and searching trying to identify the black, or possibly VERY VERY dark purple hummingbird we had on 22June2020 in North Carolina; we were seated about 15 feet away from the feeder, and still had plenty of light. I've never seen one like that, and everything I turn up online says all the dark ones stay in Central and South America. Wonderful picture you took!

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  4. I saw a black hummingbird, in my yard. I live in Eastern Kansas.

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  5. I have a drab grey/brown Anna's hummingbird at my feeders now. You can see it on the Hummingbird Spot Live Cam. It appears to lack eumelanin so it is brownish overall. We have named him Knight.

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  6. I saw a black hummingbird at home about 3 hours ago in Spanish Town Jamaica

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  7. Black hummer outside my bathroom window this am. Smallest and only black hummer I've ever seen. About 2" to 2.5" wingspan. Feeding on tiny blooms of unidentified frond.

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