Triangle Island Seabird Research and Monitoring Program

Triangle Island Seabird Research and Monitoring Program

See the website:

http://www.sfu.ca/biology/wildberg/bertram/triangle/trgindex.html

1. Natural history of Triangle Island

2. History of human occupation of Triangle Island

3. History of scientific investigations at Triangle Island

4. Centre for Wildlife Ecology research program at Triangle Island

         (a) Core program

                  (i)   Formal protection for marine habitat

                  (ii)  Climate change

                  (iii) Seabird oiling and bycatch       

         (b) Graduate student projects

         (c) Acknowledgements   

1. Natural History of Triangle Island

Situated near the northern limits of the California Current oceanographic zone, and within the territorial boundaries of the Kwakiutl District Council, the Anne Vallée Ecological Reserve at Triangle Island supports the largest and most diverse seabird colony in British Columbia. Triangle is the outermost of the Scott Islands Group, lying some 45 km off the northwestern tip of Vancouver Island, and 10 km west of its nearest neighbour, Sartine Island. This island complex consists of a roughly triangular-shaped main island, plus a smaller island (Puffin Rock) joined to it only at low tide; there are also several small, associated offshore rocks. Triangle is part of the Scott Islands Provincial Park, and has been designated an Important Bird Area. In addition, it will soon lie within the Scott Islands Marine Wildlife Area, being designated under the Canada Wildlife Act primarily to protect critical habitat for the millions of seabirds that depend on these waters throughout the year.

Triangle Island has a cool, moist climate, characterized by moderate annual precipitation (mostly rain), frequent fog, and strong winds.  The winds occasionally reach hurricane force. These environmental conditions inhibit trees from growing on the island, but soils rich in nutrients and heavily fertilized by birds create ideal conditions for growth of low-lying vegetation: salmonberry fluorishes, and other common species include Pacific crabapple, tufted-hairgrass, salal, and a variety of ferns.

As with its terrestrial habitat, the nearshore waters around Triangle Island teem with life, including many species of shellfish, crabs, urchins, sponges, and an abundance of fish. The terrestrial invertebrate fauna remains largely unstudied, apart from brief, pioneering surveys by researchers from the British Columbia Provincial Museum – now the Royal British Columbia Museum – in the 1950s.

Few terrestrial mammals inhabit Triangle, the only native species being Keen’s mice and Townsend’s voles. In addition, domestic rabbits were introduced by lighthouse keepers in the early 1900’s, and are now well established. Triangle provides important mating and pupping sites for two species of marine mammals – harbour seals and Steller’s sea lions – and a third, the California sea lion, may also mate and pup in small numbers. The Steller’s sea lion rookery at Triangle Island is the largest in Canada, and in the aftermath of alarming population declines in parts of Alaska in recent decades, is now the second largest in the world. In addition, a few immature male elephant seals loaf on the island’s beaches every summer, and sea otters and a variety of cetaceans, including grey and humpback whales, orcas, and Pacific white-sided dolphins, can occasionally be seen passing by within sight of the island.

Triangle Island is home to many species of breeding birds, including Northwestern Crows, Common Ravens, Fox and Song sparrows, Winter Wrens and Orange-crowned Warblers. Many other species of birds, including a variety of shorebirds, visit the island on their spring and fall migrations. Among shorebirds, Triangle supports only a breeding population of Black Oystercatchers. The island also supports several nesting pairs of Bald Eagles and Peregrine Falcons, top predators that must find life on the island easy.

But it is the seabirds, 12 breeding species in all, that numerically dominate the avifauna of Triangle Island. The island supports a very large population of Cassin’s Auklets (possibly 50% of the world population!), British Columbia’s largest colonies of Tufted Puffins and Common Murres, and a sizable population of Rhinoceros Auklets. Triangle’s other breeding seabirds include Pelagic Cormorants, Leach’s and Fork-tailed Storm-petrels, Glaucous-winged Gulls, Pigeon Guillemots, and several more. It is the presence of such large, internationally significant seabird populations that bring researchers from the Centre for Wildlife Ecology to Triangle Island every spring.

Among the species of particular interest to us are:

            Cassin’s Auklet: This is a small (175 g), nocturnal, burrow-nesting member of the family Alcidae. It lays a single white egg, which the parents take turns incubating for about 38 days. After it hatches, both parents usually return once each night to feed zooplankton to the chick (mainly copepods and euphausiids, plus some larval fish), which they carry in a special throat pouch that develops for this purpose prior to the breeding season. At about 45 days of age, the chick leaves the burrow to begin an independent life at sea (i.e., it “fledges”). Triangle Island supports about 500,000 breeding pairs of Cassin’s Auklets.

            Rhinoceros Auklet: This unusual member of the Alcidae is actually a puffin, not an auklet. It is medium sized (525 g), nocturnal, nests in burrows and feeds mainly on fish. It too lays a single white egg, which is incubated in turn by both parents for about 45 days. Like Cassin’s Auklet chicks, Rhinoceros Auklet chicks are usually fed once each night by each parent – one billful of small fish, which might include Pacific sandlance, Pacific saury, and even some young Pacific salmon – until it fledges at about 55 days of age. Triangle supports about 40,000 breeding pairs of Rhinoceros Auklets.

            Tufted Puffin: A large (780 g) species of Alcidae, this is perhaps the most ornate and beautiful member of the family. Unlike Cassin’s and Rhinoceros auklets, Tufted Puffins have a diurnal pattern of activity on the colony, but like their smaller relatives, they too nest in earthen burrows in which the female lays a single white egg. Both parents incubate in turn for about 45 days, then each delivers a billfull of food to the chick once to several times per day. Interestingly, while the adults themselves feed mainly on large zooplankton, they feed small forage fish such as sandlance to the chick. The chick fledges after 40 days or more in the burrow. Triangle Island supports about 30,000 breeding pairs of Tufted Puffins.

            Common Murre: Social and engaging, this largest species of Alcidae (1 kg) nests shoulder-to-shoulder on open cliff ledges, forming the densest breeding aggregations of any  bird (in some situation, up to 75 pairs or more per square metre!). The female lays a single egg that varies in colour from off-white to brilliant green-blue, and is marked with scribbles and rings and blotches, signals that the adult birds use to help them recognize their own egg. The egg hatches after about 33 days of incubation. Because they nest in the open, rather than in crevices or burrows as most other alcids do, one adult murre must remain with the chick to brood and protect it at all times. The off-duty parent delivers single fish several times per day. Murres, and their close relative the Razorbill (an Atlantic species), are unusual in that the chick remains at the breeding site for only about three weeks, at which time it departs to sea, having attained less than one quarter its final adult weight. While mother remains at the colony, father accompanies the chick to sea and continues to feed it for up to 2 months, enabling the chick completes its development. Triangle Island supports about 4,000 breeding pairs of Common Murres.

 

2. History of human occupation of Triangle Island

Remote, steep-sided, and frequently battered by harsh weather and rough seas, Triangle Island was never inhabited year-round by First Nations’ peoples. It was visited in summer, however, because the island and its surrounding waters support a rich diversity of life, and provided skilled people with excellent opportunities to hunt and gather food. A testament to the importance of Triangle Island to its seasonal inhabitants, there is a large midden on the island that contains the bones of many species of marine mammals and birds (including Short-tailed Albatrosses!), as well as seashells of all kinds. The Tlatlasikwala First Nation is considered to be the “Gatekeeper” of all the Scott Islands, including Triangle.

Much later, a lighthouse was erected on the island, with construction completed in 1910. However, life and lightkeeping at Triangle proved nearly impossible. In fact, the top of the island is so high, and so frequently lost in fog, that the light often was not even visible to boats from the sea! A badly failed project, the lighthouse remained active for only ten years before being dismantled.

Currently, Triangle Island is designated as an Ecological Reserve by British Columbia’s provincial government, and human visitation is strictly regulated: permission from the provincial Ministry of Water, Land, and Air Protection is required before any person can set foot on the island. Crews from the Centre for Wildlife Ecology visit the island and conduct their research under permit from the provincial and federal governments, and provide annual reports on their activities at Triangle Island.

 

3. History of scientific investigations at Triangle Island

 

Following up on surveys by researchers from the British Columbia Museum in the 1950s, in the 1970s the Canadian Wildlife Service began integrated studies of Triangle Island’s seabirds. This research was led initially by CWS Research Scientist Kees Vermeer, who conducted pioneering studies of seabird breeding biology on Triangle. Later, in the 1980s, CWS biologists Gary Kaiser, Michael Rodway and Moira Lemon led field crews that carried out the enormously difficult task of determining the size of Triangle’s seabird populations (in fact, they estimated the size of seabird populations in the entire province!). These studies, along with those of University of British Columbia PhD student Anne Vallée and Simon Fraser University MSc student Doug Bertram in the 1980s, provide a critical baseline of information against which results of research later carried out by the Centre for Wildlife Ecology can be compared.

 

The existence of this baseline was one of the main reasons why, in 1994, the CWE’s Fred Cooke and Ian Jones selected Triangle Island as the site at which to establish a long-term seabird research and monitoring program. Following Ian’s departure in 1995 to a research chair position at Memorial University with the Atlantic Cooperative Wildlife Ecology Research Network (the Atlantic counterpart to the CWE), Doug Bertram returned to lead the Triangle Island program. When Doug left in 2001 to head up the Marbled Murrelet Recovery Team as a biologist with the Canadian Wildlife Service, Mark Hipfner became Scientific Director of the Triangle program.

 

4. Centre for Wildlife Ecology research at Triangle Island

(a) Core program

Ultimately, the main objective of the core research program at Triangle Island is to provide the information necessary to enable the Canadian Wildlife Service to achieve its long-term conservation objectives for marine birds. These goals are outlined in The Management Plan for Seabird Conservation, Pacific and Yukon Region (2002), which details the conservation threats and issues judged to be top concerns for marine birds in the Pacific and Yukon Region: (1) lack of formal protection for breeding colonies and critical marine habitat; (2) climate change; (3) seabird bycatch; (4) oil pollution; (5) forest exploitation; and (6) introduced mammalian predators.

Our core research program at Triangle Island addresses a number of these issues, either directly or indirectly; some others are not relevant to Triangle, which has neither forests nor introduced predators (and we take careful steps to prevent introductions!). It is also already formally protected as an Ecological Reserve.

Three research projects – one completed in 2002, one ongoing since the 1970s, and one that we began only recently, in 2002 – illustrate some of the ways in which research conducted by the Centre for Wildlife Ecology assists the Canadian Wildlife Service in achieving its conservation objectives for marine birds:

(i) Lack of formal protection for critical marine habitat

In the late 1990s, the Canadian Wildlife Service put forward the Scott Islands Group Marine Area for designation under the Canada Wildlife Act, thus demonstrating its commitment to marine conservation. The Scott Islands Marine Wildlife Area is being created primarily to protect key habitat, such as foraging habitat, for the huge numbers of seabirds that use these waters throughout the year. However, a critical information gap became apparent early in the process: What are the foraging ranges of seabirds that breed on the Scott Islands? And more specifically, where do they  forage?

To answer these questions, researchers from the Centre for Wildlife Ecology placed radio transmitters on Cassin’s Auklets breeding at Triangle Island during the chick-rearing periods of 1999, 2000, and 2001. By flying transects in fixed-wing aircraft, they were able to locate the radioed birds at sea. The same techniques were used to locate foraging areas of Rhinoceros Auklets breeding on Triangle in 2002.

What did we find? In 1999 and 2000, radioed Cassin’s Auklets were detected mainly 50-75 km southwest of Triangle, off the continental shelf break and over very deep water, in association with dense concentrations of Neocalanus copepods. In 2001, they foraged at similar distances but in that year to the north and west of Triangle, and again over deep water. In 2002, radioed Rhinoceros Auklets foraged mainly up to 80 km to the north of Triangle, on the shelf in waters just over 100 m deep, where they likely were obtaining forage fish such as Pacific saury.

The important thing to note is that, without information on foraging ranges and foraging locations, the original boundaries proposed for the Scott Islands MWA were too small to encompass these important areas. But provided with information on foraging ranges and locations by CWE researchers, CWS biologists were able to draw up biologically relevant boundaries for the MWA. The process leading to the designation of the Scott Islands Marine Wildlife Area is scheduled to conclude by spring 2004.

(ii) Climate change

Ocean temperatures vary both in the short-term (within and among years), and the long term (over periods of many decades), dramatically affecting marine ecosystem processes. For example, in the California Current, ocean temperatures increased through most of the second half of the 20th century, peaking in the mid-to-late 1990s. This warming had a marked effect on ecosystem functions, such that production of zooplankton in this oceanographic zone declined by 80% over this period! As events occurring at low trophic levels generally cascade through to upper levels, it is not surprising that populations of some California Current seabirds, notably Cassin’s Auklets, declined in the closing decades of the 20th century. These observations pose some interesting questions: What biological mechanisms link environmental variability (such as warm ocean temperatures) to seabird demographic processes? And what are the consequences for seabirds in BC? 

From the outset, a major focus of the CWE’s Triangle Island research program has been to assess the ecological and demographic responses of seabirds to ocean climate variability. This information, which builds on research conducted by CWS in the 1970s and 1980s, will be vital to understanding how seabird populations might respond to long-term, anthropogenic climate change. We also expect that the results will be widely applicable to other areas and to a variety of marine wildlife.

Our approach to this issue has been to monitor inter-annual variation in vital rates (adult survival and breeding success), variation in adult body condition, and variation in nestling diets and growth. In addition, we are investigating whether adult birds feed at different trophic levels in years in which ocean climate differs, using stable isotopes analysis, a relatively new research technique, and investigating the consequences of this variation. We are also conducting experimental studies on the roles of food availability and adult quality in driving seasonal trends in breeding performance (thought to be a key indicator of environmental conditions), and studies of the responses of important forage fish prey, particularly Pacific sandlance and Pacific saury, to ocean climate variability. Much of the CWE research has been done in association with biological oceanographers from Canada’s Department of Fisheries and Oceans.  We hope that these studies, and others, will provide us with a novel perspective on ecosystem processes and how they affect marine birds and other wildlife.

What have we found? During the period 1994-2003, breeding success (here measured as “fledgling production“, the mean mass of fledged chick produced per egg laid) of both Cassin’s and Rhinoceros auklets was lower in years with higher ocean temperatures. The birds were affected at all stages of breeding: in warm years, females were less likely to lay eggs, those that did were less likely to hatch their eggs, fewer of the chicks survived to fledge, and the few chicks that did fledge were light in mass (which does not bode well for subsequent survival). Ocean climate seems to influence the abundance and availability of important prey such as Neocalanus copepods for Cassin’s Auklets, and Pacific sandlance for species such as Common Murres, Tufted Puffins, and Rhinoceros Auklets, that usually feed their chicks on fish. Not only that, but there was evidence that survival of adult Cassin’s Auklets from one year to the next was very low during the second half of the 1990s, which was the warmest period.

Interestingly, we now have evidence that the Cassin’s Auklet population at Triangle is recovering since the switch back to a colder ocean regime in 1999. With reproductive success having improved since then, in recent years we have  been capturing more birds overall (note that the mean number caught per night banding session in 2003 approached levels from the mid-1990s), and especially more young birds (those with brown eyes), at our night banding stations. Do these trends reflect normal population fluctuations for the species, perhaps driven by large-scale oceanographic processes like the Pacific Decadal Oscillation, or were the declines in the late 1990s anomalous? To answer questions like that, we need information gathered across many, many years.

While this research mainly focuses on Cassin’s and Rhinoceros auklets, we also monitor key demographic parameters for Pelagic Cormorants, Leach’s Storm-petrels, Glaucous-winged Gulls, Black Oystercatchers, Tufted Puffins, and Common Murres. By monitoring the breeding activities of a variety of species, and species that feed at a variety of trophic levels, we hope to obtain a comprehensive understanding of the relationship between seabird biology and the marine environment. To that end, we are also involved in collaborative ventures with other researchers along the Pacific coast.

(iii) Seabird bycatch and oiling

Recent analyses indicate that the Common Murre is one of the species most often killed as a result of fisheries bycatch and chronic oiling in waters off the British Columbia coast. This has raised concerns about the population-level effects of this mortality, still basically unquantified, on murres in the P&Y Region. And we know that numbers in neighbouring Washington State have been declining for at least the last decade, with high rates of bycatch possibly contributing to the declines.

More than 95% of all murres that breed in BC have historically bred in the immediate vicinity of Triangle Island (the majority on Puffin Rock), so the population status of Common Murres at Triangle is essentially equivalent to their status in the entire Region. Therefore, an obvious question arises: What is the population status of Common Murres at Triangle Island, and elsewhere in BC? And if the population is declining, is anthropogenic mortality due to bycatch and/or oiling an important factor?  

To answer this question, we began a demographic study of Common Murres at Triangle Island in 2002, and have been monitoring annual variation in vital rates (adult survival and breeding success), as well as chick diets and growth rates. In addition, in summer 2003 we resurveyed all murre breeding sites around Triangle Island, and made comparisons with results of a 1989 survey conducted by CWE graduate Dr. Michael Rodway.

What have we found? Results of the 2003 survey suggest that Common Murres have abandoned satellite colonies at Castle Rock and Murre Rock, and now are breeding at much higher densities on the main colony at Puffin Rock. However, numbers in 2003 were down about 25% overall from 1989. Interestingly, conditions for breeding, as judged by adult mass dynamics, reproductive success, and chick growth rates, appear to be very favourable for murres at Triangle. If that is the case, any population declines may well be being driven by factors operating outside the breeding season.

We will continue to monitor the situation at Triangle, and in collaboration with partners, hope to undertake a complete survey of all historical murre colonies in the P&Y Region in 2004 (including Triangle again). Once we have the information we require, we will be in a situation to make informed and appropriate recommendations, if required.

(b) Graduate students, past and present

Obtaining rigorous, relevant, reliable and resource-efficient scientific information to enable the Canadian Wildlife Service to achieve its conservation objectives for marine birds is a key objective of the Centre for Wildlife Ecology’s research program at Triangle Island. A second, related, and equally important objective is to provide opportunities for high quality graduate student research, be it pure or applied.

Over the 10 years of the CWE’s Triangle Island program, 4 graduate students have obtained MSc degrees from Simon Fraser University based on research conducted at Triangle. Two others are in the process of completing their degrees. The abstracts to theses that have been completed can be obtained by following the links; information on ongoing theses is also available. A broad range of research topics have been addressed, and this and the high quality of their theses testify to the high quality of students who have conducted graduate research at Triangle.

Yolanda Morbey, MSc 1995                                      Thesis abstract

Hugh Knechtel, MSc 1998                                         Thesis abstract

Louise Blight, MSc 2000                                            Thesis abstract

Carina Gjerdrum, MSc 2001                                       Thesis abstract

Gwylim Blackburn, MSc in progress                         Thesis preview

Eric Davies, MSc in progress                                                 Thesis preview

 

(c) Acknowledgements

Over the years, the CWE research program at Triangle Island has been funded by the  Baillie Foundation, the Canadian Wildlife Service, the Climate Change Action Fund, the Important Bird Areas Community Action Fund, the National Oceanographic and Atmospheric Administration, the Natural Sciences and Engineering Research Council of Canada, the Nestucca Trust Fund, Simon Fraser University, the Science Horizons Program of Environment Canada, the Vancouver Foundation, and the World Wildlife Fund Canada.

We thank the many people, far too numerous to mention – volunteers, contractors, graduate students and others – whose dedication in the field has been primarily responsible for the success of the program over the years. We also thank everyone who has provided invaluable logistical support of our field camp at Triangle Island: the Canadian Coast Guard, especially the officers and crews of the vessels Sir Wilfred Laurier, Bartlett, and Narwhal, as well as helicopter pilots and crews; staff of British Columbia Parks, especially Martin Duick, Ian Maclellan, Rik Simmons and Linda Phillips; Bob Percheski of Cooper Air; and the staff at West Coast Helicopters. And lastly, we are deeply indebted to Judy Higham, Joanne Harrington, Barb Sherman, and Connie Smith for their indefatiguable support of our field camp and research activities from back home in Vancouver.

From the Triangle Island Seabird Research and Monitoring Program  website: accessed June 2014.