J.N. ‘Ding’ Darling National Wildlife Refuge
Nothing of note happened before we left for the J.N. ‘Ding’ Darling National Wildlife Refuge but it’s never a dull day with Christian driving and today was no exception.
We must have been about halfway through our journey and unfortunately at the same moment our proxy driver Iain had taken his eyes off the road Christian had decided to play bumper cars. I remember Iain and a few other people suddenly shout Christian before hard braking and hitting into the back of the vehicle in front.
Fortunately however we had slowed down enough to avoid doing any major damage and once a rather sheepish looking Christian had exchanged insurance details with Lance, the driver he hit we were on our way again. Lance didn’t seem to take it too badly and remarked ‘I’m just glad you’re on the right side of the road’. All we had a scrape on our vehicle and a slight dent on Lance’s rear bumper.
We had let the other two mini buses know we were delayed and they had waited for us just ahead. Wynn wasn’t very pleased when she found out what had happened when we arrived at Ding Darling.
On a more positive note the weather was better here with the foggy start at the Vester giving way to warm sunshine and temperatures of 21°C/70°F.
The refuge itself is on (you guessed it) another barrier island, the Sanibel Barrier Island, which was created a national wildlife refuge by an executive order from President Truman in 1945 at the urging of Ding Darling who was a famous cartoonist and conservationist.
The refuge would then be named after him in 1967, five years after his death. More on him in the next blog post.
The reserve is 6,400 acres in total with 2,800 acres designated as a Federal Wilderness Area by Congress. Habitat types include cordgrass marshes (Spartina), seagrass beds, West Indian hardwood hammocks and of course mangroves. It is managed by the U.S. Fish & Wildlife Service.
The main aim of the reserve is to provide a refuge for migrating and breeding birds and prevent it being developed on. Rare species that are present here are the manatee (Trichechus manatus), wood stork (Mycteria americana) and up until three years ago an American crocodile (Crocodylus acutus).
White pelicans (Pelecanus erythrorhynchos) overwinter here before migrating back to Canada and Northern U.S. to breed in colonies of up to 10,000. There is also an abundance of heron species such as the rare reddish egret (Egretta rufescens), and the little blue heron (Egretta caerulea) and this is also a good place to see the anhinga (Anhinga anhinga), often referred to as the snake bird.
Although Sanibel is largely an estuarine environment it is one of the few barrier islands to have natural freshwater marsh. The estuary was dyked off in the late 1960’s to control the breeding mosquito population much like Merritt Island. Just like Merritt Island they also realised the damage to the ecosystem this was doing.
Now they allow water levels to naturally fluctuate with the tide and are lowered artificially in the spring and autumn to coincide with bird migrations to give maximise the feeding area for wading birds.
Ding Darling also has to deal with invasive species like the Brazilian Pepper (Schinus terebinthifolius) and though they use fire to mimic natural cycles for native plants they control invasives with chemical and mechanical treatments.
One of the reasons why the birds populations are so high is due to the high fish populations, one of the key species being striped mullet (Mugil cephalus) which we saw shoals of when we walked/drove round. The mangroves act as fish nurseries, protecting young fish from predation.
Ding Darling is also home too a large population of Atlantic horseshoe crabs (Limulus polyphemus) which is critical for the bird life as each female produces between 15,000-64,000 eggs depending on size. This serves as a very large food source.
A big effort is made to monitor the birds at Ding Darling. This involves canon netting & ringing and also the efforts of resident photographers who are out in the field daily.
The rarest bird at the refuge is a sub-species of the red knot (Calidris canutus rufa) which breeds here and winters at Tierra del Fuego at the southern tip of South America.
Once we had been introduced to our guide, Judy, we set off much like we did at Merritt Island in the vehicles to drive/walk around and see some of the bird life for ourself. Just like before you can stand just feet away from herons, egrets and anhingas.
If you look carefully along the shoreline as well you can spot the brown anoles (Anolis sagrei) scampering around, fairly well camouflaged against the brown of the shoreline.
Overall I think we saw more birds here than at Merritt Island as it was low tide, allowing the birds to come onto the mudflats and feed. These included Judy’s beloved roseate spoonbills (Platalea ajaja), which I will be devoting an entire blog on.
Following our car trip we went back to the visitor centre just before lunch to watch a video, much of the information I have already mentioned above.
After that we were free to go around the boardwalk whilst eating lunch and soaking up the sun. One of the reasons I much prefer the boardwalk to the trip in the car is that you can go round at your own pace and take your time which is vital if you’re looking out for reptiles.
I saw a lot more brown anoles as you might expect but I managed to see some snake as well which made a nice change, including a few salt marsh snakes (Nerodia clarkii) and a corn snake (Pantherophis guttatus).
The waters here were also noticeable phenolic rich and were a very dark brown. This was probably due to how low flow rate of the water was around the base of these mangroves.
This is also a good areas to see the pneumatophore of the mangrove, which they use as a gas exchange surface, as you look down on them from the boardwalk.
I also got a good view of a strangler fig (Ficus aurea) just off of the side of the boardwalk. These parasitic plants germinate in the tops of trees, descending roots down to the ground before rapidly expanding.
They grow upwards towards the light, which is a limiting factor in densely forested. Over time the host tree dies as the strangler fig absorbs all the nutrients and light.
Barefoot Beach
That afternoon we headed back to the Vester to drop our things off before going to the local beach, barefoot, for another afternoon of swimming in the sea and basking in the sunshine.
Special Encounters at the Vester
To cap the day off I had two amazing mammal encounters. The first was my encounter of a river otter (Lontra canadensis) which swam right up to my GoPro as it was hunting the fish I was trying to film. We both gave each other a fright as you can see in the video below.
I had never seen an otter in the wild before so to come this close as my first ever encounter was pretty special.
The second encounter was with animals I missed the other day at Lovers Key, the manatee. This was also an amazing counter as it was a mother and a calf just feet away from us as we stood on the overhang at the Vester.
They persisted there, feeding for about ten minutes before moving away into deeper water. Luckily almost everyone managed to get a good view and a few decent photos.
What was sad though is the obvious scars on the adult female from collisions with boats, this is very common sight. This is minimised as best as can be by warning boat drivers to slow down in areas that manatees are known to inhabit.
I think it’s safe to say we had an exciting day!
From Marshes to Mangroves 