When swimming in open waters, it pays to keep your ducks (or your goslings!) in a row. A recent study examined the waves generated behind adult water fowl and found that babies following directly behind them benefit from their wake. In the right spot behind its mother, a duckling sees 158% less wave-drag than it would when swimming solo. That’s such a large reduction that the duckling actually gets pulled along! And the advantage doesn’t just help one duckling; a properly-placed duckling passes the benefit on to its siblings as well. So any duckling that stays in line has a much easier time keeping up, but those who slip out of the ideal spot will have a much tougher time. (Image credit: D. Spohr; research credit: Z. Yuan et al.; via Science News; submitted by Kam-Yung Soh)
Swimming in Line

RIchard Bready
Like wake-riding dolphins. It would be interesting to know if the ducklings vary positions or have a hierarchy equivalent to “teat fidelity” in kittens and piglets (blogs.scientificamerican.com/dog-spies/the-common-wisdom-about-dog-nipples-is-wrong/). If steadily occupied, that pole position advantage should free up a lot of calories for growth.