Tuesday, June 24, 2014

The Blue Hole

The “Lower Keys” consists of Big Pine Key to Key West.
When many people think of the Keys, they think sand and saltwater. While there are both of those features here, you may be surprised to learn that we don’t have the BEST sandy beaches here, and we have an abundance of fresh water. The Lower Keys, where I live, is built on a fossilized coral reef.

Because of this coral reef, the ground is very hard, beaches are not that sandy, and there is coral EVERYWHERE. This also means that freshwater is able to be held in what is referred to as a “lens” just under the surface of the ground. Elevation on Big Pine is less than 5 feet above sea level, and it is probably more accurate to say its less than 2 feet in elevation. This lens just hovers under the surface, and has allowed animals and people to inhabit this island. There are many freshwater wetlands on Big Pine Key, which is surprising to many, including myself. While I’m out on the Refuge, I’ve noticed many shallow, open water habitats, all of which is freshwater.

Many years ago, when these islands were really being developed, in an attempt to raise roads, the railway and buildings, some of this fossilized coral, now limestone, was quarried. Have you ever dug a hole in the ground, and hit the water table? That’s what happens here, in the quarries.

The Blue Hole at dusk.
One of my favorite spots on the National Key Deer Refuge, is the Blue Hole, which is one of the abandoned quarries. It has since filled in with freshwater, but also contains a layer at the bottom of denser saltwater. This is primarily considered a “freshwater habitat” but, after Hurricane Wilma in 2005, several saltwater species of fish (tarpon and barracuda) washed in, and can still be seen today. I’ve witnessed the tarpon breaching, and it’s pretty impressive!

The Blue Hole is probably most famously home to several alligators (Alligator mississippiensis). These ‘gators can be seen often sunning themselves, from the safety of a wooden observation deck overlooking the pond. Of course these are wild animals, and there is no fence keeping them contained, so visitors should keep their distance, and refrain from feeding them.

One of the 'gators seen at Blue Hole.
The Blue Hole also has many species of birds that frequent the area, that may not be seen elsewhere because of the abundance of freshwater here. My favorites so far this summer are a nesting pair of Anhinga (Anhinga anhinga) (+1). There is clearly a male and a female that are attentive to the nest, but there is also what I’ve deemed to be a juvenile, unsure of sex. This bird has been observed plucking dead sticks as well as green sticks, and passing them off to the pair, as well as swimming and roosting near the pair. I haven’t been able to figure their situation out, but the nest is close to the observation deck, and I’ve been getting some great pictures!

Male (standing) and female on nest.

Here the juvenile Anhinga was observed about 30 feet from the nest, and both adults, gathering nesting material? Apparently you can’t determine sex of an Anhinga until after it’s 3rd winter, so I don’t know if this is male or female yet.

This night, I was fortunate to watch the female take over the nest from the male. The video quality isn’t the best (sorry), my camera was constantly trying to focus, and I was without a tripod! Still, it was awesome to watch.

Mom is now on the nest, and dad tends to her and the nest.
A White-crowned Pigeon 
seen feeding amongst poisonwood.
The next bird I finally got a picture of at Blue Hole, but found all over Big Pine Key, is the White-crowned Pigeon (Patagioenas leucophela). These birds are unlike other pigeons or doves that we’re all familiar with. They are uncommon in the Keys, except for this time of year, and they are very timid and wary. They’re seen flying in small groups, and feeding in poisonwood, which is a nasty cousin of poison ivy. They eat the fruit, and nest on the more remotes islands of the Keys. It’s been difficult to catch one close enough, and sitting still to get a picture. I’m pleased with the one at left!

These birds are at their northernmost range in Florida, but are common throughout the Caribbean island. They are even hunted and eaten in those islands. Here in Florida though, they are protected. I am glad to add another member of this Pigeon/Dove family to my bird list, to expand past the Rock Dove and Mourning Dove!

While I was trying to photograph the above Pigeon, I kept hearing a musical song and frenetic movement in the canopy over me. I couldn’t get a good look at it, as it was moving quickly and it was reaching dusk. I finally was able to pinpoint it, and get a good look at it. The picture below is the best I could do given the lighting and the bird’s behavior. Before I left Blue Hole for the night, I was guessing that I had photographed a warbler or vireo, just based on it’s location in the canopy, and I saw it feeding on insects (both warblers and vireos are insectivorous).

White-eyed Vireo (Vireo griseus)

After getting home, and sending my picture to my ornithology professor from SUNY Cobleksill, I confirmed that it was a White-eyed Vireo. Check it out at All About Birds: White-eyed Vireo, and give it’s song a listen.

The last bird I got the chance to see, was an Osprey (Pandion haliaetus). He was quite a distance away, sitting on a snag. But the sky was beautiful behind him, so he’s included!

Osprey at Blue Hole

The FINAL cool critter I saw over at Blue Hole the other night was a Florida softshell turtle (Apalone ferox). We had a soft shell in our herpetology lab at Cobleskill, which could fit in the palm of my hand. It was so different than any other turtle or tortoise I had seen. Their shell is leathery and soft, and they have a little snout on them, which they can use as a snorkel!

I saw this Florida softshell at Blue Hole, right next to an alligator. They were totally unconcerned with each other. This turtle was probably 12-14″ from end to end of his carapace (top shell). Really cool animal.

Florida softshell turtle
More to come soon, as I get the time and inclination to post! Happy summer!


  1. This is very different from your time in Alaska, and lovely video, it looks as though they are so careful not to leave the nest open for any time at all, and her eyes!!! So clear. Lovely turtle, I can see you are having a great time down there. Cheers, Jean.

  2. It is so interesting - what a change for you!!!! The birds are incredible, and it's fun to learn about the Keys.


Thank you for reading and wishing to leave a comment! Unfortunately, due to a high number of spam comments being left under the "Anonymous" heading, I had to disable that feature. You may still leave a comment with a Gmail account, or under the OpenID option! I welcome comments, suggestions, stories, and tall tales!