Anhinga in Florida with a very reddish neck? (1 Viewer)

Among dozens of nesting anhingas in Delray Beach, FL, most of which are typical all-black males or half-black, half-buff-necked females...or the downy white juveniles...I spotted one that stood out quite a bit. I can't figure out if this is a known or normal variant color for anhingas, a more rare anomalous color, just an odd fluke, or if this was a hybrid or different species than the 'anhinga anhinga'. The reddish to chestnut color on the lower part of the neck and chest were very vivid and noticeable even from 70+ feet away. I've included a photo if anyone can clarify if this was common, rare, or something new.

So you are saying that the color was noticeable in the field, so we can exclude photo artifacts?

In that case, could it be that this bird has visited a location with more iron or other stuff in the water so that the color difference is staining? that would be my first guess - similar to what Sandhill Crane is able to do during summer.

Niels

It stood out very clearly - even as I approached the island from about 100 feet away I noticed the reddish color before I knew what the bird was...the island has several dozen anhinga nesting on it (along with several dozen wood storks, egrets, herons, etc). Indeed it could be almost anything - I hadn't considered water source or food source but I suppose that's a possibility...the only thing that makes me wonder if it's external staining is that it doesn't seem to have impacted some of the buff colors on the wings, or the white wing markings, and of course the upper part of the neck still seems the typical buff color. I guess he may have not submerged his upper neck and head in that location, staining only his lower neck and body.

A few more anhinga shots from the same location, nearly the same light, here are two other juvenile anhingas in the much more typical buff-neck color that all the other birds had:
https://g3.img-dpreview.com/8816496021FF4652A0D9CE61FDC36279.jpg

And another flying past:
http://www.pbase.com/zackiedawg/image/167455611/original.jpg

It could just be some natural occurrence, staining of some kind, or just an odd anomaly...I just wondered since other breeds of anhinga in the world DO have this type of reddish color on their necks, such as the 'anhinga rufa' species...I wanted to rule out that this wasn't some strange escapee or hybrid.

I'd say iron staining from iron-rich water.

Thank you. That's starting to sound like the most likely scenario. And certainly possible - we're had lots of rain, followed by a week or two of almost no rain, and the water levels in some canals and smaller ponds were going down again - lots of various colorations to the waters in the main wetlands from tannins and other influences - it would certainly be possible this guy found an iron-rich pond or puddle, or muds as the water levels dropped. Everything's filled back up again over the past 3 days as we're back into strong rainy season, with 7 inches in the last couple days.

I thought females in full breeding plumage looked like this - An even more striking example from Neil's gallery.

https://www.birdforum.net/gallery/showphoto.php?photo=519452