A re-interpretation of the function and evolution of the tail streamer in hirundines.

In the article The function and evolution of the tail banner in hirundines, the authors attempt to explain the mechanisms behind the morphology and evolutionary information of tail streamers in the group B swallow. They debate that the tail streamers establish a trait shaped by the trade-offs between silky efficiency and reproductive benefits mediated sunk female pick (Rowe, Evans and Buchanan, 2001). The effects of tail streamer duration manipulation is time-tested in barn swallows and a close related species, the backbone martins, who lack the tail streamer, by the make use of of a rush maze. Eighty four barn swallows and lambert seven gritrock martins underwent tail streamer manipulation and successfully made it through the escape valve maze. The manipulations consisted of removing various lengths of tail streamers in the barn swallows, and the addition of similar lengths of streamers to the ends of the outer tail feathers of the keystone martins using an ad hesive. The flight maze consisted of an eighteen meter margin which presented the birds with 9 meters of impediment free acceleration zone followed by a nine meter maneuverable obstacle zone. The obstacles consisted of ordered rows of strings suspend from the roof which were spaced in progressively tighter rows towards the end of the maze. In order to get through the maze, the birds would strike to perform increasingly tight turns around the strings and thence required elegant maneuverability on their part.

The time interpreted for the birds to get through the maze as well as the number of strings they e ncountered during flight were taken as co-va! rying measures of distributively birds flight performance. The results indicated that the barn swallows benefited from increasingly shortened tail streamers up to a uttermost of approximately 12 mm at which point come on shortening actually change magnitude flight performance. The sand martins on the other... This is a good deal on a ad hoc case in the surmisal of evolution. The scienctific report at arrive at is interpreted truly well and give specific cases. If you necessitate to get a full essay, order it on our website: OrderCustomPaper.com

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