Fitch High School, Cane Toads, and Cahows

For Connecticut science teachers Charmaine and Kevin, Bermuda has always been special.  The couple fell in love with the island during their honeymoon, and soon returned with groups of Fitch High School students.  The pair began a Bermuda ecology course in Connecticut, which culminates in a fieldwork-based trip to the island.  Now, after 18 years of bringing students to Bermuda through BIOS, the island still hasn’t lost its charm. 

During their week-long stay at BIOS, the Fitch High School students snorkeled at Whalebone Bay, learned about the conservation project at Nonsuch Island Nature Reserve, explored North Rock, and much more.  I was able to join the group on their trips to Nonsuch Island and North Rock to document their trips, and learn why they look forward to returning to BIOS each year.     

On Thursday afternoon I met the group down by the docks.  After the safety briefing, we headed out to Nonsuch Island in the Castle Harbor Islands Nature Reserve.  Nonsuch Island is a reserve and wildlife sanctuary where conservationist David Wingate has spent his lifetime restoring and helping bring the endemic Bermuda Cahow sea bird back from near extinction. 

I spoke with Charmaine and Kevin on the boat ride over about their experiences bringing students to BIOS. Both couldn’t say enough good things about BIOS, and explained how the program has a significant impact on the students that they bring. “The people at BIOS have been great,” Charmaine said.  “For a lot of kids this is the only time they get to go to Bermuda.  The students learn to appreciate different cultures, see the beauty of the island, and for a lot of students this trip is the first time that they have been on their own.”  

The pair explained that some of the students who participate in the trip return the next summer with a new group, and help by teaching some of the classes and mentoring the students.  Kevin said that this becomes a valuable leadership opportunity for the students. 

  

Soon we caught sight of the light turquoise-colored waters surrounding Nonsuch, and the students excitedly got their dry bags ready.  Because the water is too shallow to dock, the captain anchored a little off shore, and the students helped load up the kayak with their dry bags. We all jumped in and swam to shore as Kyla, the Program Assistant for BIOS Ocean Academy, brought the loaded kayak in with her.  Once the students were ready, Kyla began the walking tour of the island.  She stopped along the way to point out some of Bermuda’s unique flora and fauna.

Eradicating the invasive cane toads

At one point, Kyla stopped to point out a black plastic wall enclosing a pond.  She asked the students what function they thought the barrier served.  The students were quick to guess that it was to keep an animal out.  That animal, as we found out, was a toad.  

 

We were all in awe as Kyla explained that the cane toad, Bufo marinus, has been observed swimming all the way from the mainland in search of fresh water!  Amazingly, the cane toad can smell the freshwater across Castle Harbor. These determined toads are the same ones that Bermudians commonly refer to as ‘road toads’ because they frequently are seen squashed in the road.

David Wingate published a paper in 2010 describing the success of the barrier in eliminating the invasive cane toads from the island.  Wingate explains how the cane toads threatened the endemic Bermuda skink and the seriously endangered Bermuda petrel, or cahow.   To try and rid the nature reserve of the invasive cane toads, Wingate and his team came up with a “non lethal method of removing toads” by installing “a toad barrier around the freshwater pond, constructed of robust high density polyethylene (HDPE).”  Because the toads rely on freshwater as breeding sites, they were unable to breed and consequently captured by Wingate’s team during the night.  Amazingly, Wingate and his team carried out the nighttime toad raids for 5 years until all toads were removed before they reached reproductive maturity.  After the 5 years, an impressive 1,244 toads were returned to the mainland. 

The barrier remains to discourage any more toads from coming to the island and Wingate estimates that only one toad per year tries to migrate to Nonsuch.  Because that rogue toad can be captured quickly, Wingate reports that the toad is now gone from the island and that his research paper “is the first published report of a successful eradication of the species from an island with breeding habitat.” 

Devils Isle and Cahows

Further along in the walking tour, Kyla said that the reason that Bermuda was called Devils Isle was because of the screaming cahows that people heard from aboard the ships.  It was thought that their screeches sounded like ghosts of people killed in shipwrecks.  Kyla also explained that in the 1620’s there was a widespread famine on the island and the settlers essentially eradicated the cahow.  With her arms stretched out, Kyla said how the cahows would mistake humans (which they had never encountered before) as trees, and would land on their limbs.  This made the cahows an easy target for the starving settlers, who would simply pick them off their arms and legs and cook them.  

In less than 20 years of settlement, the Cahow declined to the point where it was thought to be extinct, a belief that persisted until the rediscovery of 18 remaining nesting pairs on four offshore islets in 1951.  A 15-year old David Wingate, who was with the group when they found the pairs, left inspired.  After university studies, Wingate returned to Bermuda, driven to help bring the Cahow back from extinction. 

Kyla showed us some of the artificial nesting sites that the Cahow Recovery Programme has installed in order to encourage Cahows to reproduce.  Although remaining critically endangered, there is now hope for the Cahow on Nonsuch Island.  Wingate's conservation and recovery program on Nonsuch Island has successfully increased the number of Cahow breeding pairs from 18 in 1951 to 92 pairs in 2010.  The Cahow Recovery Programme is now recognized as one of the most successful restoration projects for a critically endangered species, and was highlighted in the first World Seabird Conference in Victoria, British Columbia, in September, 2010.  

 

The BIOS experience

The students seemed to really enjoy the tour of the island, and got a chance to do some snorkeling before heading back to the boat.  Once aboard the boat again, I spoke to a few of the students about their experience at BIOS.  One student, Alex, said, “I think it’s cool to be around all of the scientists here, and see the type of work that they are doing.  It’s so interesting to hear about their latest research.”  Another student, Sam, had the opportunity to experience some of the friendly Bermudian spirit, “One thing that struck me is how nice the people are here.  They smile and greet everyone they see."

Lauren is on her second trip to BIOS and told me, “It’s an amazing experience to see a lot of things that most people don’t get to see.  It has been a really unique experience.” Lauren explained that her favorite part of her time at BIOS has been being able to go diving, “It’s so amazing that I get to have this opportunity and I’m only 17.”  It was Mackenzie’s first year at BIOS and also her first time out of the country. “This trip has changed what I thought I wanted to do,” she said. “ Now I am interested in pursuing a career in marine biology.” 

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It is evident that the love that Charmaine and Kevin have for Bermuda and for BIOS is now shared by so many of their students.  We can’t wait to welcome next year’s group, and show them all why Bermuda and BIOS are so special.