The pink-footed shearwater is a member of the order Procellariiformes, along with fulmars, albatrosses, petrels, storm petrels and diving petrels. From the perspective of species diversity, the Southern Hemisphere represents the center of distribution for this group of seabirds; however, many of the species are wide-ranging and highly migratory, crossing both ocean basins and hemispheres. As such, this group of species is recognized globally as an integral part of the marine ecosystem and its conservation is of common concern to many nations. Concerted, coordinated efforts to protect and conserve these birds are taking place within the Southern Hemisphere; however, there is a need for complementary programs within the Northern Hemisphere.
The pink-footed shearwater ranges through the eastern Pacific from its breeding sites on the islands off the coast of Chile, to wintering areas off the coasts of Canada, Mexico, and the United States (COSEWIC 2004).
The species is listed as “vulnerable” by the World Conservation Union (IUCN) (BirdLife International 2004a), and was recently listed as “threatened” by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) (COSEWIC 2004). However, due to a lack of historical information on total population size and the extent of colonies throughout the breeding range of the pink-footed shearwater, quantitative estimates of population trends are non-existent for the species. Additionally, the pink-footed shearwater faces a variety of potential, yet poorly documented threats, at sea throughout the species’ range, and at the breeding colonies. These include predation by introduced predators, human disturbance and exploitation, habitat destruction, seabird-fishery interactions, oil pollution and ingestion of plastics (BirdLife International 2004b; COSEWIC 2004).
Focusing attention on issues affecting the conservation of the pinkfooted shearwater at the North America level will help to enable the determination of the status of the population, and the clarification of threats. This may also provide an opportunity to establish cooperative conservation efforts within Canada, Mexico, and the United States, that link with those in the southern hemisphere.
Puffinus creatopus Coues, 1864, commonly known as the pink-footed shearwater, is a stocky and rather broad-winged seabird. In flight, individuals appear heavy, with labored wingbeats (Martin and Myres 1969; Sibley 2000). The plumage is a combination of grayish-brown upperparts, white underparts with smudgy markings, mottled underwings, and a dusky head (Harrison 1983; Sibley 2000). The iris is brown, the bill pinkish- yellow with a dusky tip, and the legs and feet are pink. Juveniles and adults are alike in plumage, as are the sexes, with no seasonal variation (Harrison 1983). Adult length averages 48 cm, the wingspan 109 cm (Harrison 1983), and weight 744 g (Hodum and Wainstein 2002, 2003; range 620–880 g, Hodum and Wainstein unpubl. data). The diet of pink-footed shearwaters breeding on Isla Santa Clara in the Juan Fernández Archipelago is dominated by fish, with squid comprising a smaller proportion of the diet (Hodum and Wainstein unpubl. data).
The pink-footed shearwater occurs primarily in the eastern Pacific, although there are records from New Zealand and Australia, and a specimen was collected from the Atlantic coast of Argentina (BirdLife International 2004b). The marine range extends northwards along the coast of South and North America at least as far as the south coast of Alaska (American Ornithologists’ Union [AOU] 1998), although relatively few individuals are seen north of the northern end of Vancouver Island, British Columbia, Canada (Vermeer et al. 1989). Vagrants have been recorded west to the Hawaiian and Line islands (Harrison 1983), and north into the Gulf of Alaska.
This species is known to breed on three islands off the coast of Chile: Isla Mocha, Isla Robinson Crusoe (Más á Tierra) and Isla Santa Clara (AOU 1998). Recent evidence suggests that there may be another colony on Isla Guafo, south of Isla Mocha.
Following breeding, the pink-footed shearwater disperses northward along the west coast of South America towards North America. The migration is evident by the increasing presence of the species along the continental shelf (0–200m depth) from the Gulf of California in Mexico to British Columbia in Canada, during April and May each year. Numbers tend to peak between August and October, followed by a rapid decline in numbers during November as the birds return to their breeding colonies (Wahl 1975; Ainley 1976; Guzman and Myres 1983; Briggs et al. 1987; Vermeer et al. 1989; Hatler et al. 1978; Tershy et al. 1993). While very little is known of the birds’ occurrence in Central America during migration, they likely move rapidly through this area (Stiles and Skutch 1989). Although pink-footed shearwaters are known to occur in all seasons off Peru and Chile, in the northern part of its range the species’ presence is largely restricted to the boreal spring and summer months (March to November). Pink-footed shearwater population densities and the northern extent of their range are believed to be strongly influenced by interannual variability in ocean temperature off the west coast of North America (Schwing et al. 2002; Hyrenbach and Veit 2003).
The earliest accounts of the pink-footed shearwater stem from the diaries and ship logs of sailing vessels that visited the Juan Fernández Islands in the late 1600s and early 1700s. Sailors would capture ‘birds,’ presumably pink-footed shearwaters, at their burrows on Robinson Crusoe for food. Breeding colonies in the Juan Fernández Islands, specifically those on Robinson Crusoe, were discovered’ and documented by Reed in 1874, although he misidentified the species (Murphy 1936). A visit by Beck in the austral summer of 1913–1914 confirmed breeding and correctly identified the species as the pink-footed shearwater (Murphy 1936). Beck (in Bent 1922; Murphy 1936) and Lönnberg (1921) generally described the breeding distribution on Robinson Crusoe, with both noting abundant burrows. Beck also visited Santa Clara and documented burrows near the top of the island. No estimates of breeding population were provided in any of these accounts.
There appear to be no reports of the Isla Mocha population until the early 1930s, although island residents presumably knew about this population before it was documented. Murphy (1936) referred to a report from a visit by Bullock in 1932 in which he confirmed that pink-footed shearwaters were an abundant resident of Isla Mocha. He described steep forested hillsides literally honeycombed with burrows. No population estimates were made, however.
Due to this lack of historical information on total population size and the extent of colonies throughout the breeding range of the pink-footed shearwater, quantitative estimates of population trends are non-existent for the species. The BirdLife International Species Factsheet provides a global estimate of 34,000 to 60,000 pairs (BirdLife International 2004b). However, despite the uncertainty surrounding the species’ global population size, a number of factors exist that suggest that populations and habitat may have been affected.
Populations on Robinson Crusoe in particular are believed to have declined in the past, primarily as a result of depredation by coatis (Nasua nasua) (Guicking and Fiedler 2000) introduced to the island during the 1930s (Inter-American Biodiversity Information Network 2003). Feral cats and rats are also present on Robinson Crusoe (Bourne et al. 1992; Hahn and Römer 2002; Hodum and Wainstein 2002, 2003), with historical accounts indicating the presence of cats since the early 1600s (P. Hodum pers. comm. 2003). Based on the knowledge that feral cats and rats on seabird islands often have devastating effects in other parts of the world, it is almost certain that the shearwater colony on Robinson Crusoe has been affected by them. There are no records of introduced mammalian predators on Santa Clara. European rabbits (Oryctolagus cuniculus) were apparently eradicated from the island in 2003. However, it is quite probable that while they were on the island, they likely competed with the shearwaters for burrows (Schlatter 2002; Hodum and Wainstein 2002, 2003).
The harvesting of chicks from the breeding colonies at Isla Mocha was first reported in the early 20th century and, although illegal, it continues to the present day. Remarkably, the scale of the operation has never been determined, and it is therefore impossible to estimate how this activity has affected the population.
On both Robinson Crusoe and Santa Clara breeding burrows are located in open terrain with grassy vegetation (Guicking and Fielder 2000). It is likely, however, that the breeding habitat at both locations was once heavily forested. With active deforestation and the introduction of herbivores (including sheep, cattle, horses, donkeys, and goats) prior to and during the 20th century, the extent of many forested areas has been greatly reduced (Hahn and Römer 2002). Until recently, European rabbits were also prevalent on Santa Clara (P. Hodum pers. comm. 2004) and their presence strongly contributed to the loss of vegetation (Bourne et al. 1992; Guicking and Fiedler 2000; Hahn and Römer 2002). By increasing erosion, this habitat loss likely affected breeding populations indirectly in the past through the destruction or alteration of burrows. Recent research on Santa Clara has documented the inter-seasonal disappearance and destruction of burrows in several subcolonies because of erosion during the winter months. In addition to outright destruction of burrows, erosion on Santa Clara also alters burrows, typically by shortening the entrance tunnels (P. Hodum, pers. comm. 2004).
The pink-footed shearwater currently is not listed as threatened or endangered under the US Endangered Species Act nor is it included in the US Fish and Wildlife Service list, Birds of Conservation Concern (BCC) (USFWS, 2002). The species was listed as Endangered in 1994 in Mexico (NOM-ECOL-059), but was subsequently delisted in 2001. In May 2004 the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) listed the pink-footed shearwater as Threatened in Canada. Globally, the pink-footed shearwater is listed as Vulnerable under criteria D2 (as below) by the IUCN, and is included in Appendix 1 of the Convention on the Conservation of Migratory Species of Wildlife Animals:
D. Population very small or restricted in the form of either of the following:
2. Population with a very restricted area of occupancy (typically less than 20 km2) or number of locations (typically five or fewer) such that it is prone to the effects of human activities or stochastic events within a very short time period in a uncertain future, and is thus capable of becoming Critically Endangered or even Extinct in a very short time period.
Despite probable declines in the past, populations in the Juan Fernández group appear to have been more or less stable over the past 15 years. In contrast, populations on Isla Mocha are believed to be declining, most likely due to the effects of chick harvesting (Guicking 1999).
The pink-footed shearwater faces a number of threats, both on the breeding colonies and at sea. The main terrestrial threats are from introduced predators, human disturbance and exploitation, and habitat destruction. The importance of each of these differs between breeding locations. Given the birds’ highly pelagic, wideranging habits and their substantial annual migrations, both seabird-fishery interactions and oil pollution may represent substantial at-sea threats. However, there is currently no information on the extent or relative impact of each of these on the pink-footed shearwater at the population level. Risk assessments should be conducted to explore these issues.
Although coatis are present in somewhat reduced numbers relative to their abundance prior to the 1980s (Hahn and Römer 2002), it is likely they still represent a threat to the population of pink-footed shearwaters on Robinson Crusoe (Guicking and Fiedler 2000). Feral cats and rats are also present on Robinson Crusoe (Bourne et al. 1992, Hahn and Römer 2002, Hodum and Wainstein 2002). Recent evidence from the 2002–2004 breeding seasons suggests that predation in several of the larger colonies on Robinson Crusoe may have been due to cats and/or coatis primarily (Hodum and Wainstein 2002, 2003).
Ship (Rattus rattus) and Norway (Rattus norvegicus) rats are known to occur on Isla Mocha, where they have been observed entering burrows. Eggshell fragments have also been found on the forest floor, suggesting rat depredation. In addition, dogs often accompany harvesters into the forest and likely take chicks from short burrows or those sitting outside their burrows (Guicking 1999).
5.2 Exploitation and habitat destruction
Although the practice of harvesting chicks for food is illegal on Isla Mocha, they are considered a local delicacy and approximately 20 percent of the annual chick production (3,000–5,000) is harvested each year, from March to May, by the island’s residents (Guicking 1999). The effects of this activity also extend beyond harvesting. While chicks in short, straight burrows can be easily harvested; burrows that are too long or twisted are usually dug open and therefore destroyed. Only those nests underneath massive root systems or those on steep, inaccessible sites are safe from harvesters (Guicking 1999).
In relation to historic habitat loss as outlined above, extensive erosion on Santa Clara, in particular, annually destroys or alters a substantial number of burrows in some of the subcolonies (P. Hodum pers. comm. 2004).
5.3 Seabird-fishery interactions
During the breeding season, pink-footed shearwaters from Isla Mocha show a strong preference for foraging in areas that also support an extensive fishing industry (Guicking et al. 2001). Interaction between the species and the industry is therefore highly likely. However, there is currently no information available on the nature or extent of these interactions. Research is currently underway to investigate the foraging locations of adult pink-footed shearwaters breeding on Isla Santa Clara; one of the goals of this research is to evaluate these locations in relation to fishing activities (P. Hodum pers. comm. 2004). At this stage it is unknown if there is overlap between the two. If overlap occurs, it will be important to determine not only the type (e.g., longline, trawl, gillnet, purse seine, etc.) but also the scale (small-scale artisanal or large corporate) of the fisheries, as these will provide insights into the likely interactions, if any.
The distribution of longline commercial fishing activities overlap both spatially and temporally with the wintering range of the pink-footed shearwater over the continental shelf of North America, making the risk of interaction with the fishing fleet highly likely. Although at-sea observer programs are critical in order to evaluate seabird bycatch, and while programs currently exist in the United States and Canada, observer coverage is predominantly low and observer training to identify seabird bycatch has been variable. There are currently no seabird observer programs in the Pacific waters of Mexico.
In British Columbia, Canada, observer coverage in longline fisheries has gradually been increasing but it is still limited (spatially and temporally), and it has not reached the Department of Fisheries and Ocean’s target level of 25 percent. By 2002, observer coverage in the Canadian Pacific commercial halibut fishery reached 18.6 percent of hooks hauled, whereas in the commercial rockfish fishery only 10.5 percent of hooks hauled were observed (Smith and Morgan, in prep.).
Individual observer programs are designed to meet specific goals and, thus, may result in different primary foci. Although seabird bycatch is typically a relatively low priority in these programs, it has been a primary focus of several US-sponsored programs (S. Fitzgerald pers. comm. 2004). Even in those programs in which it is not of primary importance, observers typically record bycaught seabird species. Because pink-footed shearwaters appear to be a rare bycatch species in US and Canadian waters, current fishery coverage levels and sample sizes are likely inadequate to document their bycatch rate.
Fouling of pink-footed shearwaters by petroleum products also represents a potential significant threat in many parts of the species’ marine range, including Mexico, the United States and Canada. This could result from accidental or deliberate releases of petroleum products from platforms, ships or terrestrial sources, and has the potential to cause mortality of individuals as well as seriously impacting the foraging habitat and/or prey of the pink-footed shearwater. The species is known to raft on the water in large groups in both the breeding and wintering range (Guicking and Fiedler 2000, K. Morgan pers. comm. 2003), which increases the risk of severe mortality from spills, either chronic or major events.
Ingestion of plastics is also a concern. Seabirds are known to consume plastics at sea, presumably mistaking them for food items. This ingestion can lead to injury or mortality through internal injuries from sharp pieces of plastic, or through a reduction in ingested food volumes and subsequent dehydration and malnutrition (Sievert and Sileo 1993). Young birds may be particularly vulnerable to plastic ingestion prior to developing the ability to regurgitate (Sherburne 1993). Recently collected diet samples from adult pink-footed shearwaters breeding on Santa Clara have contained pieces of plastic (P. Hodum pers. comm. 2004).
There are currently no identified management actions for the pink-footed shearwater in the United States or Mexico. In May 2004 the species was listed as Threatened in Canada by COSEWIC. The Governor in Council is now responsible for deciding if the pink-footed shearwater will be added to the List of Wildlife Species at Risk under the Species at Risk Act (SARA), 2002 in Canada. Should this occur, there will be a requirement for a Recovery Strategy for the pink-footed shearwater to be completed within two years.
There are currently no targeted efforts to build public awareness to protect the pink-footed shearwater in North America.
An Overview of the North American Conservation Action Plans
As mandated by the 1994 North American Agreement for Environmental Cooperation (NAAEC), the Commission for Environmental Cooperation (CEC) encourages Canada, Mexico and the United States to adopt a continental approach to the conservation of wild flora and fauna.1 In 2003, this mandate was strengthened as the three North American countries launched the Strategic Plan for North American Cooperation in the Conservation of Biodiversity.
The North American Conservation Action Plan (NACAP) initiative began as an effort promoted by Canada, Mexico, and the United States, through the Commission for Environmental Cooperation (CEC), to facilitate the conservation of marine and terrestrial species of common concern.
The main assumption supporting this initiative is the need and opportunity to enhance—through coordination—the effectiveness of conservation measures undertaken by diverse countries sharing migratory or transboundary species.
Building Partnerships to Conserve Species of Common Concern
The implementation of the Strategic Plan for North American Cooperation in the Conservation of Biodiversity calls for identifying an initial set of North American regions and species for which the benefits of cooperation could be more effective and best illustrated. Two regions, one marine and one terrestrial, stood out that spanned the three countries: the Baja California to Bering Sea region and the central grasslands. Current activities developed in these regions include the identification of priority conservation areas within them as a basis for establishing an institutional conservation network.
Similarly, the countries, through the CEC, agreed upon an initial set of marine and terrestrial species of common conservation concern for which North American Conservation Action Plans would be developed. The initial six species (three marine and three terrestrial) were selected for these conservation action plans because of their ecological significance, their level of threat and the opportunities they present for joint action.
The goal of a NACAP is to facilitate a long-term cooperative agenda for the conservation of these species of common concern throughout their ranges of distribution in North America. Through each NACAP, the CEC provides a valuable planning tool to help focus limited resources and ensure that cooperative actions taken for the conservation of species of common concern are based upon sound science, and are targeted at priority actions. The implementation of these actions, however, is incumbent on the diverse players of each country.
The expected users of a NACAP are principally those organizations and individuals engaged in the conservation of shared North American species, including governments at the various federal, state/provincial, local and indigenous, tribal/first nations levels, and civil society.
The pink-footed shearwater North American Conservation Action Plan
This NACAP, developed for the pink-footed shearwater (Puffinus creatopus), resulted from a trinational workshop hosted by the CEC in San Francisco, California, in March 2004, and benefited from the in-depth review of an extensive list of wildlife experts from diverse backgrounds from Canada, Mexico and the United States. Furthermore, the content of this NACAP has been shared with diverse government agencies found within each country related to the well-being of the species.
The pink-footed shearwater action plan is divided in eight sections, providing a trinational outlook related to the species. The initial four sections provide an updated account of the species and its current situation. The fifth section identifies the main causes of loss or decline and puts in perspective the ensuing sections related to current management and actions taken in each country, as well as public and commercial perception of the species and the threats it faces. Against this background, the last section offers a list of key trinational collaborative conservation actions. The identified actions address the following main objectives:
- An evaluation of the conservation status of the pinkfooted shearwater at a continental level;
- Threat clarification at the wintering grounds;
- Capacity building for research and at-sea monitoring in Mexico;
- A program to further awareness of the species throughout its range in North America; and
- Catalyzing conservation actions as related to specific issues identified under Status Evaluation and Threat Clarification.
We hope that over time efforts such as the NACAPs will indeed provide an effective basis for cooperation and networking among diverse sectors of society working on the well-being of these species and their habitats across North America.
Hans Herrmann and Jürgen Hoth
Biodiversity Conservation Program
Commission for Environmental Cooperation