If you have not visited Guam, it is likely you are unaware of Guam’s lack of birds. You may wonder what would lead to the decline of a once very healthy bird population. The answer is relatively simple – the invasive brown tree snake. The brown tree snake (BTS) is native to Indonesia, the Solomon Islands, New Guinea, and Australia. The BTS was first sighted on Guam in the 1950s, likely brought over via a cargo ship from New Guinea. This arboreal snake feeds on lizards, birds, small mammals, and eggs. Encountering no native predators on Guam, the BTS multiplied uncontrollably in the jungle… leading to the near extirpation of Guam’s native birds.
Since returning to Saipan a few days ago to begin my field work for the summer, I have noticed a stark difference in ambient sound. Saipan is loud. Not with cars or air traffic, but with bird song. I step outside and am immediately greeted by an avian chorus. Even now, as I sit at my desk, I can hear them through closed doors… different songs from a variety of birds diving through the sky, chasing one another, and perched on a nearby telephone pole.
Guam is silent. No bird sounds when I step outside, except for the occasional chicken cluck or chirp of a small chickadee. Mostly I hear a cacophony of car and air traffic. Sometimes this noise even drowns out the distant sound of waves crashing on the beautiful reefs. When it comes to birdsong, Guam is a silent island.
I am reminded of Silent Spring by Rachel Carson, the renowned environmentalist. In her book, Carson documents the environmental damage caused by various pesticides in the 1940’s and 1950’s, illuminating that pesticides often impact more than the targeted pests – causing problems across the food chain through bioaccumulation. Insects, birds, and fish — to cite a few examples — have been silenced due to imprudent use of pesticides. Carson writes, “Over increasingly large areas of the United States, spring now comes unheralded by the return of the birds, and the early mornings are strangely silent where once they were filled with the beauty of bird song.” While the cause of the silence to which she refers is pesticides, the parallels to the invasive brown tree snake of Guam are uncanny.
The contrast of Silent Island Guam to loud, song filled Saipan is stark. I am filled with joy every evening I sit outside on the latter smaller island and just listen. Listen to the birds, the hum of the bugs, and the sound of the tall grasses and palm trees rustling in the light breeze. Nature can — and should — be enjoyed with all the senses, not just sight. Given the opportunity to hone in on nature’s smallest details and sounds has enhanced my appreciation for nature in a way I have not experienced in some time. Rachel Carson summarized this experience in just five simple words, “In nature, nothing exists alone.”