Monday, March 02, 2015

Circle of Life



The Farallon Islands are a great place to observe wildlife. It's a small piece of rock with a huge diversity and abundance of life, from the tiny Anna's Humming bird to the giant Blue Whale. Even after a few months living here, I am still amazed by the daily spectacle.

Examples of the diversity of wildlife on the Farallon Islands.


During the winter, this scene is even more interesting with the breeding season of elephant seals. Their size and power contrast with their peaceful and serenity during the day until dominant males start to fight to defend their territories. Every day more and more cows arrive and soon after their installation in the colony they give birth to a “small” pup, cute little thing who will do nothing else than eat and sleep for the next few weeks. At the same time, seabirds start to prepare the breeding season, coming back to the island, as Western gulls, Cassin's auklets and Common murres staying in giant groups on each piece of available rock. However, this density and diversity of animals living and giving birth on the island, all this profusion of life must coexist with death. Here, as everywhere else, there is no life without death, and in such environment we experience this observation every day. Nonetheless, death is not a unique and simple thing. Even if the result is the same there are different kinds of death, some are harder to see than others.


The most common kind of death we encounter here is the one I would call “normal death”, a death being part of the ecosystem equilibrium, from the relationship between a predator and its preys. The best examples are the Great White sharks eating the yearling elephant seals, or the Peregrine falcons consuming gulls and murres. It's almost every day that we'll find the rest of a carcass just eaten by one of these raptors present on the island.
 
During a dew soaked morning walk around the island a daily encounter with "normal death". The aftermath of a Peregrine falcon kill on a Common murre. One drop of blood on a white feather.


This daily observation is part of our job, and when I find a dead bird just freshly killed, I don't feel sad. It's part of the process of life, one animal dies for the survival of another. A “normal death” for a “normal life”.


It's harder to face the second kind of death: death by starvation. This winter season we witnessed more of it. The huge abundance of life along the California Coast comes from an up-welling a few miles off shore, bringing cold water and nutrients from the bottom of the ocean. This current has a huge impact on the food chain. The nutrients are used by the phytoplankton, eaten by the zoo plankton, then eaten by the fish, which are in turn eaten by the top predators such as seabirds, pinnipeds or dolphins. But this year, the water is warmer, there are less nutrients, therefore the environment is less productive and each level of the food web is impacted. From the island, we don't see what is happening in the water, but we can easily find out it's not a normal year based on the poor conditions of animals living here. During this winter, we found several birds dying, with no visible injuries but not able to fly, and a few days later not able to walk, and dead the next day.

A Brown pelican with a broken wing.


Seabirds are not the only ones impacted by this poor season. As well as cormorants or gull, sea lions seem to be in bad condition. The last few months we observed many individuals with bones visible, without fat and muscles, and therefore promised to a certain death. This kind of death is a long process, and a lot more difficult to see than an owl eating its daily meal.

An emaciated yearling California sea lion in Mirounga Beach.

Most of the birds and sea lions dying by starvation are juveniles. They have less experience in hunting and even during a good year their probability to survive is lower than adults. However, it doesn't mean that older individuals are doing well. Indeed, there is a third kind of death I wanted to talk about, taking part even before birth: fetus abortion. Because of the lack of food, pregnant females are not able to fight for the life of their growing fetus inside them. The energy involved in this process is too important to be completed without enough food around the island. Since December, we have seen more and more aborted fetuses found throughout the colony. It's a really sad scene to see these small creatures already formed but not completely ready to live in this world. It's even more impressive to see these little guys still alive a few minutes after their birth and dying quickly because they are too premature, with no fur, too small, not able to move. 

However, this is nothing compare to the reaction of the mothers. It's difficult to know if the abortion is because of a wanted process, or only because of a reaction from the body, but we can see the sadness of the female. Many times we see females doing a strange call just after the birth. Usually, their first reaction is to shake it, move it, expecting a reaction, a breath, or a call... but nothing will come. After a few minutes the gulls are coming to clean this sad scene, but the young mothers will defend it as long as possible, until they understand there is nothing to do. However, a few of them will not leave the dead fetus, and will bring it into the water, maybe to protect it from the gulls. It's really a weird thing to see a sea lion walking with a dead fetus in its mouth, and disappearing in the ocean. The most surprising thing is to see the other sea lions present in the colony running away from this mother carrying its dead offspring. They look scared by the death.

  video


We are here in a surprising island, in this amazing environment, to study life, wildlife, but everyday reminds us that this environment is real and death is never far away.
   
Words, photos and video by Aymeric “Meumeu” Fromant