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Darwin Was Right: Island Animals Are Tamer – Yahoo News

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Darwin Was Right: Island Animals Are Tamer – Yahoo News.

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It’s Shark Week!

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As shark week comes to a close I would like to take a moment to discuss these magnificent creatures. As I child I had a fear of most predatory animals, though I had very little real world experience with them to set the foundation of this fear. However this fear led me to learn about them. While originally intended to teach me how to protect my selves from these “monsters”, what I learned taught me to respect and love these creatures rather than hate and fear them. I have stated this before during my post on wolves, the link to which can be found at the end of this post, and it has been the same in regards to my relationship with sharks. I have found myself in the water with sharks on numerous occasions throughout my life and I have never felt like I was in any danger. For instance while in the Galapagos Islands I swam with species such as Galapagos sharks, white tips, and hammerheads. I have even been in the water with the feared bull shark while snorkeling near Key West, Florida though I was not fortunate enough to see the shark personally (it was spotted and identified by our captain).

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I will say I was overall disappointed with the programming on Shark Week this year. In fact I gave up watching it after the first three days as this years programming seems to have lost the focus of what Shark Week is about. With mockumentaries like “Megalodon” and countdowns of the most dangerous sharks in the world the overall theme this year seemed to be “it is not safe to go in the water”. Meanwhile, discussion of shark conservation and real facts about sharks was more or less limited to flashcards between shows and commercial breaks. So I wanted to take the time to correct this lack of focus by Discovery Channel and have a real discussion on sharks and shark conservation.

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Sharks should rightly fear us much more than we fear them. On average there are only four people a year killed by sharks. While there are certainly more attacks than this, the number of human victims of sharks pales in comparison to the number of sharks harmed by humans each year. In fact, it is estimated that humans kill anywhere from 70 million to 100 million sharks each year. This persecution by humans has led 20% of shark species to the brink of extinction. Many of these deaths are accidental due to indiscriminate fishing practices, however a large portion of this killing is intentional to feed demand for shark products in Asia. Anyone who has watched shark week has likely heard of the demand for shark fin soup which is considered a delicacy in China. However, a less known use of sharks is for their cartilage which is believed to fight cancer. This by the way is false and science has proven that chemicals in shark cartilage can actually be harmful to humans.

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While the overall theme this year may paint sharks as ravenous killers this is certainly not the case. Only 20 species of sharks, out of the 350+ recorded species, are known to attack humans. Great white sharks, some of the most feared in the world, are actually picky eaters. Often they attack once and leave as they can determine with a single bite whether or not the target will satisfy its nutritional needs. This is why many humans receive “test bites” rather than full on predatory attacks.

Literature cited:

https://wildlifeconservation101.wordpress.com/2012/10/12/wolf-hunting-opens-in-wisconsin/

http://dsc.discovery.com/tv-shows/shark-week/shark-facts/top-100-shark-facts.htm

http://animal.discovery.com/fish/shark-fishing.htm

Scientists: Galapagos tortoise can be revived – Yahoo! News

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Building off of my post about the Galapagos I have found an interesting article related to Galapagos tortoises.

Scientists: Galapagos tortoise can be revived – Yahoo! News.

Wildlife of the Galapagos Islands

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As a wildlife ecology student my recent trip to the Galapagos Islands was the experience of a lifetime. I was so pumped about the trip that I even read Darwin’s “Origin of Species” (it was rough). From the moment I set foot in San Cristobal, my point of entry, I was completely blown away. My expectations for the trip had been surpassed within the first hour in the archipelago.

As soon as I had cleared through customs I spotted my first Magnificent Frigatebird and a couple of Blue-Footed Boobies. My first sighting of a Darwin Finch was on my way to meet up with my local guide. I felt like I was treading in the footsteps of Darwin himself as I observed the magnificent variety of bird life all around me. As my guides described it to me, the Galapagos do not have a huge diversity of species like I had seen on the mainland, but those species found in the islands are found in abundance. Imagine colonies of 70 or more Blue-footed Boobies or 400 sea lions laying on the beach.

One of Darwin's finches

One of Darwin’s finches

The most amazing characteristic of the wildlife I found on all of the islands I visited was their complete lack of fear. It was not uncommon to see a sea lion flop down on a bench next to a human. During my snorkeling trips I came face to face with Galapagos Penguins, sea turtles, and Galapagos sharks and none of them cared I was there. Sea lions would swim up to me and start trying to play by spinning in the water and bumping into me. However this lack of fear is not the result of taming or acclimation to human presence. The Galapagos do not have any large, terrestrial based, predatory mammals that are native to the archipelago. As such the animals do not see humans as a threat.

Sea lion on a bench

Sea lion on a bench

Along with some amazing photography opportunities due to this lack of fear I also had the opportunity to observe the effects of isolation and evolution. The greatest example of this were the mockingbirds I observed. The mockingbirds of the Galapagos originally evolved from a mainland species that somehow migrated to the islands. Over the years of isolation they have become genetically distinct from mainland mockingbirds. They have evolved into their own unique species, the Galapagos Mockingbird. I observed this species during my travels on Santa Cruz and Isabela. Speciation has continued with those mockingbirds found on San Cristobal though. Again they have evolved into a species of their own known as the San Cristobal Mockingbird.

San Cristobal Mockingbird

San Cristobal Mockingbird

Another great example of evolution within the species of the Galapagos is amongst the tortoises. Currently there are 11 species of Galapagos tortoises located on different islands throughout the archipelago (there were 15 species at the time of Darwin’s visit to these islands). These species are not only genetically distinct, some have developed unique shell shapes as an adaptation to conditions on their individual islands. The carapaces (shells) of tortoises on the islands I visited all had the common dome shape. However, on some of the islands like Española, which are arid and have little low lying vegetation, tortoises have developed saddle-shaped carapaces. This shape allows them to stretch their necks higher up to feed.

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  Galapagos Tortoise with domed carapace       Galapagos tortoise with saddle-shaped carapace

Galapagos tortoise with saddle-shaped carapace

Unfortunately I was unable to see the Flightless Cormorants (with no land based predators and a diet composed of fish flight is an unnecessary expenditure of energy and has thus been lost) during my visit to the Galapagos. However the trip was still an amazing experience, especially for a wildlife ecology student such as myself. Although they are somewhat difficult to get to the Galapagos Islands are an amazing destination and I would highly recommend them as a destination for nature enthusiasts.