SOUND SAVES SEAGULLS

By: Alexandrya Robinson, UHM MOP Student

Yellow-legged gull. By: Sergey Yeliseev, Flickr.

Organisms use a multitude of environmental factors in order to assess the safety of their surroundings. The world we live in is loud; everything makes noise. Auditory feedback is one method that allows organisms to interact with their surroundings, whether by creating sound or by listening to it. Recent discoveries focused on seabirds illustrate the importance of sound. The University of Vigo in Spain recently directed research on yellow-legged gull eggs. Researchers noticed that some young chicks were more responsive to the call that alerted to danger than others, which led to the burning question of why. The first step of any scientific experiment is observation, so the Behavioural Ecology Lab did just that. It was observed that the most reactive chicks were exposed to the danger call as eggs. To test if this theory was accurate, an experiment was concocted and led by Dr. Jose Noguera to collect 90 different gull eggs and run a controlled experiment. The results confirmed that eggs exposed to the danger call had chicks that were able to recognize it faster than their counterparts. Not only that, but the chicks communicated with each other. Social cues, which are vital to chick survival, were able to be transferred even when they were embryos, giving them an evolutionary advantage. Eggs who had been introduced to the danger call could pass crucial information on to other embryonic birds, so that all benefitted and were more adapted to survival once the chicks hatched. The study found that when eggs exposed to gull calls were placed with those who had not been, the more informed embryos transmitted survival cues to the others. The result was that all of the embryos made less noise, and once hatched, all of the chicks were smaller, faster, and more alert to potential threats. So far, this phenomenon has also been observed in quails, fairywrens, and zebra finches. The ability of embryos to take in social cues and pass them on to others may increase overall survival of chicks and confer numerous benefits. More research into this area is needed in order to see if other species practice this, as well, and how receptive bird embryos are to outside data.