Build It and They Will Come: Basking Rafts

January 30, 2014

Nature Notes by Bill Dunson


Many animals will perch or climb onto floating logs in ponds, protruding rocks, or sticks that hang out from the bank of ponds. In the case of reptiles such basking behavior is an important part of their maintenance of higher preferred temperatures that they cannot attain by physiological means. This allows them to digest their food quicker and grow faster. There is also the benefit of drying the skin and removal of external growths of algae and possibly even leeches and other parasites. For some diving birds such as cormorants and anhingas, their method of swimming underwater to catch fish involves allowing their modified body feathers to absorb water to control buoyancy; these wet feathers must be dried to make subsequent flight easier.

Since most ponds do not contain many if any floating logs or adequate branches protruding from the banks, it is important for our wildlife to provide them with resting places. In some cases this may conflict with what many people consider “neatness.” For this reason a large number of ponds and lakes within local communities have barren shorelines with little wildlife habitat. A “neat” environment is generally devoid of wildlife. So you must reprogram your mind to appreciate a more natural arrangement and enjoy the resulting improvement in the quality of habitat.

At Wildflower Preserve we have tried two types of simulated basking habitat floating in ponds, cabbage palm trunks and a constructed raft. The palm trunks were attractive but had two drawbacks, they tended to absorb water and sink, and they rolled when birds stood on them or when turtles tried to climb up. The first raft constructed by a volunteer carpenter, Charles Kozora, had a ramp on one end and was successful except that the anchor dragged due to the chain being too short. So we are working on some new models with two ramps and better anchors.

Another huge advantage of basking rafts is that wildlife can feel comfortable in a pond while visitors walk on the shoreline. So despite the unnatural appearance of such rafts, I feel that they are wonderful both for wildlife and those who want to observe them closely without undue disruption of their activities.

Bill Dunson

Bill Dunson

About Bill Dunson

Bill Dunson, born in rural Georgia, skipped 12th grade and went directly to Yale. Bill subsequent-ly received a PhD in Zoology from the University of Michigan, studying softshell turtles. Bill is Professor Emeritus of Pennsylvania State University thanks to a career spent entirely at that institution, teaching and doing research on the physio-logical ecology and ecotoxiciology of reptiles, amphibians and fish. Always curious about nature, Bill has dedicated his life to learning and sharing his knowledge with others. He has served on many advisory boards here in Southwest Florida to preserve the water that gives life to our region.

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