Showing posts with label seabirds. Show all posts
Showing posts with label seabirds. Show all posts

Wednesday, July 31, 2013

A Few Hours at Sea

As part of the daily routine aboard a whale watch vessel, I get to experience many things, both on the water and on board, while also recording what I see and taking photographs of whales and sharks for photo-identification purposes. The database can give a snapshot of daily and yearly views of a portion of the Bay of Fundy and can be helpful for others who can't be out as often.  Photo-identification of individuals are added to the appropriate catalogues to follow individuals and learn more about them.

In a few short hours, we can sail to a feeding area for seabirds, whales, seals and fish and experience a glimpse of an amazing ecosystem and share this with our passengers. The weather can change from restricted visibility to clear and from swell to calm seas. On July 28th, we got to experience all of these plus helped remove some threats to the marine animals and have a bit of a laugh.

We began by retrieving a poly-balloon used by fishermen to mark their fishing gear with 100 m (300') of sinking rope. The poly balloon and line had broken off its intended fishing gear and was drifting in the current.  This loose line is dangerous to a whale because of risk of entanglement. Given the growth on the rope it had been floating for awhile. It is always best to remove loose gear to prevent this hazard.  Sometimes it can be returned to the fisherman if there are identifying marks but not in this case. We then found a huge bunch of party balloons for someone's Sweet 16 birthday. When helium balloons are released they travel up into the atmosphere and are carried toward the coast.  The air is cooler along the coast, some of the helium escapes, and the balloons usually descend into the ocean where they float on the surface mimicking jellies.  They are mistakenly eaten by turtles and even whales and can cause the death of the animal from blockage.  It is a sad way to die.  Even though it looks pretty to see the balloons rise into the air, there are deadly consequences and this practice should always be avoided.

Party balloons and a loose fishing balloon with sinking rope picked up while whale watching
During the sail, we see numerous seabirds.  These birds are well adapted to life at sea.  Sooty shearwaters, for instance, only return to land when they are nesting in the southern hemisphere and even then they may spend days foraging before returning to the nest.  Their long, narrow wings allow them to glide effortlessly, particularly when they are close to the water surface which is where the term shearwater comes from.  They are in the tube-nosed bird family which also included albatrosses, petrels, fulmars and storm petrels.

Sooty shearwater in flight
Some seabirds are very tiny but yet still spend their lives at sea, except for nesting.  Red-necked phalaropes are one of those small species, a shorebird who gave up the shore.  They are often found along tide streaks where seaweed accumulates, providing shelter for small zooplankton which the birds eat.  These female red-necked phalaropes are on their way to their non-breeding area in South America and stop in the Bay of Fundy for about three weeks to double their weight and continue their journey, after laying eggs in the Arctic.  They do not incubate but leave that to the males.  Some of these females still have their breeding plumage which gives them their name.

Red-necked female phalaropes, some still in breeding plumage
Not all of the members of the whale family are large either.  This harbour porpoise calf, born in June is only about 100 cm in length. Still staying close to its mother, they do venture a few metres away at times.  Its small size is apparent when compared to the great shearwater.

Harbour porpoise calf and great shearwater
The Bay of Fundy has some very interesting oceanography and the whales and seabirds are aware of times and locations of ready prey availability which change each day according to the lunar cycle.  If you arrive at the correct time, the observations of whales and seabird feeding can be spectacular.  Although food can be abundant, the birds often fight over a fish.  This herring gull appears to be winning the fight, only to be attacked by a great shearwater, also intent on swallowing this herring.  Bite marks can be seen on the fish.

Herring gull with a herring
 The feeding aggregations can have many species including minke, finback and humpback whales, harbour porpoises, and harbour and grey seals.  While photographing this minke whale, I was also fortunate to capture a harbour porpoise with its head fully out of the water.  They are often swimming so quickly that they partly propel themselves into the air when breathing.

Harbour porpoise in the background and minke whale in the foreground, the smallest toothed whale and baleen whale, respectively, in the Bay of Fundy.  Great shearwaters and a herring gull are also in the photograph.

Finback whales are slower to surface, given their larger size, and with the right lighting conditions, more of the whale can be seen underwater.  Finbacks have an asymmetrically coloured face with the right side of the jaw being white and the left grey.  This photograph show that.
Finback whale showing the white right jaw (underwater)
We finished the trip by being entertained by one of our passengers who brought his pirate costume along.  
One of our passengers dressed as Captain Jack Sparrow
All in all, the Bay offers some amazing sights and with often calm seas in the summer, these can be enjoyed by all.

Tuesday, January 24, 2012

Continued Work on Leach's Storm Petrels

Sandy Camilleri is a graduate student of Dr. Heather Koopman at the University of North Carolina, Wilmington.  She has been studying Leach's Storm Petrels for her Masters thesis on Kent Island, part of the Bowdoin Scientific Station, in the Grand Manan archipelago.  Sandy hopes to defend her thesis this spring.



Most seabirds provision their chicks with whole or partially digested prey items whereas tube-nosed seabirds (albatrosses, shearwaters, fulmars and petrels) concentrate their prey into a lipid rich oil, called stomach oil. For her master’s thesis research she is investigating this unique strategy used by tube-nosed seabirds by comparing the lipid composition, energy content, and the contaminant levels of the stomach oil to prey items that would be fed to other species.

Leach's Storm Petrel chick.  Note the tube-nose on the bill.

The tube-nosed species chosen for this study was the Leach’s storm-petrel, which has a large population that nests on Kent Island and has been studied since the 1930s by Bowdoin College. I spent a couple of weeks learning how to properly handle petrels and how to collect stomach oil in 2009, then developing the laboratory analyses of the stomach oil. In the summer of 2010, I spent a total of 8 weeks on Kent Island monitoring and collecting stomach oil samples from petrels. A total of 83 samples were collected in 2010, 49 from adults and 34 from chicks.
Sandy Camilleri with a Leach's Storm Petrel adult on Kent Island.

In the summer of 2011, Ispent a total of 8 weeks on Kent Island, again monitoring and collecting stomach oil samples from petrels. The field season was split into two parts, the first was 2 weeks in June which was used to set up the field site, called the Ditch, monitor the burrows and collect adult stomach oil samples. The second part started in mid-July and lasted for 6 weeks. During this time, I finished sampling adults and monitored the nests daily waiting for chicks to hatch. The first chick to hatch for the summer was found in the Ditch on July 14! Once the chicks hatched, they were weighed daily and measurements of wing length and tarsus (foot bone) length were recorded as growth indicators. Once chicks were 2 weeks old, those that gained more than 10g overnight were sampled, indicating that mom and/or dad had fed it that night. A second sample from the chicks was collected at least one week after the first.
Some of the buildings on Kent Island, part of the Bowdoin Scientific Station

A total of 147 samples were collected in 2011, 72 from adults, 45 from chicks sampled once, and 30 from chicks sampled twice. All samples were brought back to UNCW where lipid analysis and energy content will take place in Dr. Heather Koopman’s lab. Contaminant analysis will be completed in Dr. John Kucklick’s lab at the National Institute of Standards and Technology in Charleston, SC.

This project will provide insights to the costs and benefits to the unique provisioning strategy used by tube-nosed seabirds. Leach’s storm-petrels are ideal for monitoring environmental health and can be used as a model for other tube-nosed seabirds that have more remote nesting locations, those that are experiencing population declines, and those that live in known contaminated areas.