Some birds (like shearwaters) have no trouble diving into and flying out of water. Others, like ducks and geese, float upon the surface then take-off whenever they want to. Others, like frigate birds, take quick baths.
If pterosaurs ever landed on the water, were they able to take-off again? And if so, how did they do it? These are good questions for which answers can only come through pure speculation, drawing on physics, analogy and imagination.
Dr. Mike Habib has worked out the problem following the pattern of his forelimb launch from land. There’s an update here. Dr. Mark Witton illustrated the feat. Habib thinks it would take several leaps from the water before enough speed could be attained to generate lift. He reported at pterosaur-net.blogspot, “Anhanguerids probably took multiple hops across the water surface to launch, but our calculations suggest that most of the actual energy expenditure was spent escaping the surface tension.” Unfortunately Witton’s drawings never get to the point of actually extending the wings, leaving the pterosaur flopping about on the surface, wing fingers always down. Not sure how anything can generate sufficient thrust from a standing start and several dunks before flapping. Seems rather awkward at best. And when do the wings actually open?
Pelican Take-off from Water
Do pelicans give us some idea how a pterosaur could have taken off from a standing start while floating on the surface? Click the image to see the YouTube video of a pelican taking off from water. Apparently keeping the wings dry is important. They rise first.
Are Pelicans Good Analogs to Pterosaurs?
Let’s put the pterosaur in the water now and see if it could lift its wings and take-off like a pelican. The pelican uses running legs and webbed feet to provide extra thrust during takeoff. The small feet of ornithochierids would not have been as helpful. Even so, the legs probably ran fast, like a basilisk (Jesus lizard) doing what they could. Most of the thrust would have to come from the flapping wings.
We Will Never Know Certain Aspects of Pterosaur Behaviour
We can only guess. Hopefully we will be able to discard those hypotheses with the longest list of problems.
As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.
Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.