Temperature: Max 21o C
After a much needed sleep we set off at 8am to Merit Island. On the drive I spotted American White Pelicans (Pelecanus erythrorhynchos) and a Wood Stork (Mycteria Americana) flying overhead which were surprisingly close to a relatively built up area. A sight that would be hard to imagine in the UK and a taster to the array of birds we would be treated to in the day to come.
As we arrived at the Merritt Island National Wildlife Refuge an Osprey flew overhead as we were taken into the educational room for a short talk by members of the US Fish and Wildlife Service. We were then treated to a drive around the refuge accompanied by a volunteer named Betty who had a vast knowledge of the history and ecology of the island.
Brief history of Merritt Island
- 1945-53– DDT used to control mosquitoes.
- 1950’s– Mosquitoes no longer respond to DDT, levees build around salt marshes to create impoundments which filled with rainwater. Controlled to disrupt saltmarsh mosquito populations. Changed predominant habitat of estuarine wetlands (saltmarsh and mangrove swamps) which added to the crash in dusky seaside sparrow populations.
- 1962– NASA purchased 140,000 acres of land for space exploration due to its transport links and isolation from human populations (The previous human residents were bought out)
- 1963– The northern part of the island was not developed by NASA. The US Fish and Wildlife Service (USFWS) signed an agreement with NASA to establish a wildlife refuge on the island.
Merritt Island is now made up of an array of habitats occupied by 1,500 species of plants and animals.
Habitat types include:
- Coastal dunes
- Freshwater impoundments
- Pine flatwoods
- Hardwood hammocks
Two major forms of management are utilised by USFWS;
Prescribed fire is used on Merritt Island to improve and maintain wildlife habitat and reduce the risk of wildfires. Wildfires within Florida were a natural part of the ecosystem occurring every 3-10 years. With prescribed fires this is mimicked in a controlled way.
Fuel load (grasses, pine needles, saw palmetto) is also reduced by controlled burning; meaning that risk from an uncontrollable wildfire would be reduced.
Water levels are also managed, previously these were used to control mosquito populations but are now used more to create and maintain the diversity of habitats for wildlife.
On the drive around the island we saw a diversity of habitats, plants and animals. The diversity of wading birds seen was vast resulting in different requirements for water depths. These are provided on the island by various impoundments and levees which are managed throughout the year, often responding to seasonal changes in water availabilities. These impoundments are also managed to control the salinity which is altered by Florida’s wet and dry season which can affect plants and prey availability.
Three different mangroves species were seen; white (Laguncularia racemosa), black (Avicennia germinans) and red (Rhizophora mangle). We were shown the zonation pattern of the three different mangroves, all of which belong to different families.
We saw a female anhinga (Anhinga anhinga) sunning itself on a black mangrove as it does not have oil coated feathers. This is because while fishing the anhinga will dive underwater for long periods at a time with only the head above water, therefore buoyancy is not useful. This fishing behaviour, later seen at corkscrew swamp.
The first mammal spotted on the trip was a group of manatees (Trichechus manatus) in a small lagoon resting. These were in an area near to a group of fishers and there were a few boats in the area seemingly unaware of the manatees presence. Manatees are listed as vulnerable by the IUCN’s Red List with over 20% of recorded fatalities in Florida being down to watercrafts (FWC, 2016). Despite the “slow speed-minimum wake” sign there was no indication that there were manatees in the area. Our guide told us that this was an area where manatees were regularly present, without signs signalling this boat collisions seemed likely in this area.
The next exciting bird we came across was the Florida scrub jay (Aphelocoma coerulescens). The Florida scrub jay is the only species of bird endemic to Florida. The scrub jay benefits from the prescribed fire management to maintain the scrub habitat it occupies. It was extremely inquisitive as we approached. This we were told, was because people often come and feed them by hand so humans are associated with food.
Later in the day we travelled to the other side of the island to Kennedy Space Centre allowing us to see how the land was being used by humans in pursuit of space exploration. These large buildings and roads would certainly have resulted in habitat loss. Without this development by NASA the protection of the reserve by the prevention of human developments would not have happened. Therefore suitable wildlife habitats would have likely been replaced with large developments seen on the mainland.