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The bobcats that inhabit Cumberland Island generate a lot of interest among our guests at Greyfield Inn. The presence of these predators has led to many discussions regarding the implications and importance of prey/predator relationships. Occasionally we see bobcats on our tours around the Island. Once they spot us however, these shy animals will usually disappear quickly into the forest. Some of the younger cats may stop and stare for a few moments out of curiosity as do the people who are just as curious about them.
Bobcats are native animals to this region but were extirpated from Cumberland in the early 1900’s. In 1988-89 the National Park Service, working with the University of Georgia, reintroduced bobcats to the Island. The plan was to get another large native predator on the Island other than the alligator (which was already here) to help balance the food chain by reducing the high number of prey species such as deer. The other reason for bringing the cats back was to conduct some intensive studies into the secretive lives of these animals and to dispel some of the myths about them so they could be properly managed in the future.
The bobcats released n Cumberland were trapped on the nearby mainland and checked for diseases. Upon their release they were all fitted with radio tracking collars. These tracking devices gave biologists the ability to learn how the cats established their territories and also locate the females at their dens to find out what their reproductive success was. This study revealed female bobcats have well defined territories while male cats roam larger areas that may cover the territories of several females. They may also breed with these females during the winter. The dens that were located had litters of two to four kittens in them during the spring months.
Twenty-eight bobcats were released on the Island but as their numbers grew, reproduction slowed down. As one biologist explained: bobcats are mostly solitary, territorial animals, if they feel crowded by other cats they can become stressed and less likely to breed. But we know they are breeding well on the Island now because there have been numerous sightings of young cats. Several times in the last year we have seen small kittens playing in the roads.
Another effort toward understanding the lives of bobcats was an extensive food study. This involved microscopic examination of the animal’s scat to see what they were eating. On Cumberland, their diet consisted almost entirely of mammals such as marsh rabbits, deer (mostly fawns), raccoons and rodents. There was some concern before the cats were released that they would destroy the Island’s wild turkey population. Knowing that bobcats and turkeys evolved and lived together in the same habitats of North America over a long period of time made this an unlikely scenario. That proved to be the case on Cumberland. Today, the Island has a large population of turkeys as well as bobcats.
Top predators nearly always get people’s attention. The secret life of the bobcat although being exposed by science, still holds a certain mystique. On Cumberland the presence of bobcats adds a higher degree of wildness to the Island, a quality a lot of visitors are searching for.
It’s February and some of the migratory songbirds are starting to pass through Cumberland. Yellow-rumped Warblers are commonly seen now while occasional flocks of Cedar Waxwings appear and feed heavily on the bright red Yaupon holly berries that are still on the trees. Another plant that brightens up the forest this month is the Red Maple with clusters of red seeds.
Maple seeds come with wings and are attached in symetrical pairs. This allows a slower rate of descent when they fall from the tree giving them a wider area of dispersal, especially if they are caught by the wind.
The Saltmarsh that borders the Island is almost entirely brown this time of year with dead stalks and leaves of Spartina grass. On calm sunny mornings however, dew covered spider webs may light up some areas of the drab looking marsh.
So while late winter may seem like an uneventful time of year, closer observation can often reveal a colorful and ordered web of life.
2 February, 2008
Winter storms out of the northeast can have dramatic effects on Cumberland’s shoreline. Sand pulled from the beach by high tides and rough seas will be deposited offshore forming sandbars. The importance of the fore dunes next to the beach becomes evident in the winter as this area becomes a buffer zone between active beach sand and the more stable ground inland. The key to slowing the erosion of these dunes are plants like sea oats. Anchored with numerous long branching roots, sea oats can hold a dune line together better than anything else. The tall stalks and leaves of this plant also slow the wind flow over the surface of the dunes and help prevent the wind driven migration of sand.
In the aftermath of a storm sea life that was dislodged from the shallowbottom washes ashore. Sand that was pulled from beach gets redeposited on shore as well. The dunes with little or no plant cover show the most dramatic effects of the storm. In these areas dune migration caused by wind can pile enough sand into the nearby forest to kill the trees by blocking oxygen from reaching their root system.
Plants and animals that inhapit the coast live in a tenuous environment where a strong northeast storm can push them beyond their limits.
