Is that a penguin?
Is that a penguin?
It has become an increasingly common question in the tide pools of cobble beach in Yaquina Head on the Oregon coast. I do not blame the tourists for mistaking these birds with penguins; they really do look like them with those feet placed low on their body which forces them to stand straight when they walk on land. However, Common Murres are far from Antarctica, where penguins live, and they are also capable of flying. Not only can they fly, but they can also do it underwater; a characteristic that separates the family Alcidae from any other group of birds.
So, what is the big deal with these brown penguin-like birds that come and go constantly? Well, these Murres are actually the remnants of a once numerous colony that has seen the return of one of its historical nemesis as a threat to its existence. I am talking about the Bald Eagle, the main predator of this colony of Common Murres. But, didn’t Murres coexist with Bald Eagles for generations even before humans even stepped on these lands for the first time? Why are the Eagles causing so much trouble now if they didn’t cause in the past? The answer is simple, but the solution to the problem is complicated. The population of Murres once exploded to unprecedented numbers when their main predator was removed in the 40’s and 50’s due to the use of the pesticide DDT, which affected the reproduction of Bald Eagles. The colony grew unchecked during all those years, eventually the old generations passed and the new ones thrived in a world with no predators. Unaware of the presence of Bald Eagles, the new generations of Murres eventually forgot what these raptors are and how to behave in their presence.
Murres reached numbers that went over the hundreds of thousands, but then humans gained consciousness about the use of DDT in the 1960’s and its use was eventually banned. It was great news for all bird and nature enthusiasts, the symbol of North America was once again ruling the skies. It is important to reiterate that the Common Murres of the coast had not seen a Bald Eagle in decades. What happens when the population of Bald Eagles gets established again in this area? They need to eat, they need to teach their young how to hunt, and they will eventually become a symbol of fear to all their prey animals. Under those circumstances, the Murres are presented with an alien creature they have never seen before, but they realize this animal is a threat. The first instinct a prey animal has when it sees a predator approaching is to fly away as fast and as far as possible in many cases leaving their nests behind.
Furthermore, when the parents fly trying to get away from the eagle, the eggs are left exposed and other predators take advantage of this situation. Gulls, ravens, cormorants, and even pelicans are the main threat to the survival of this colony; these birds eat Murre eggs. In the years prior to DDT Murres had developed a system of recognition, every time an eagle captured a bird the colony stood still and did not fly away. This predator-prey dynamic took many generations to develop and became extinct when the eagles temporarily disappeared.
In 2002 the population assessment of Common Murre on Colony Rock and Lion Head Rock (the large rocks next to the Yaquina Head lighthouse) was of 90,000 individuals. In 2013 that number went down to 30,000. It is difficult to predict what the fate of this population is going to be, Bald Eagles are a native species and for such reason lethal control is not an option. On the other hand, some Murres seem to be starting to fight back when the eagles approach; they stand still and do not move away from their nest. It is encouraging to entertain the idea that these learned behaviors might once again become common and the population will thrive.
The Common Murre story is a good example of the extent human actions can reach. At the beginning we did not know what effect DDT was going to have on birds; we then noticed it was dangerous and removed it. We invested an immense amount of effort and resources in bringing back the Bald Eagles and succeeded. For a short period of time we were able to breathe peacefully, but then we realized that the damage caused by our actions in the 1940’s still prevails today. The creation of the environmental movement and the efforts to keep it running are the strongest tools we have available to reach people and teach them to understand that the decisions we make today, good and bad, will echo on the future minds of our planet.
Note: the Common Murre is not listed as a species of special concern; however the colonies are constantly harassed by predators that a change in their status might not be far from happening.