NT
Red-legged Cormorant Poikilocarbo gaimardi



Justification

Justification of Red List Category
This species has a relatively small population which is showing moderately rapid declines owing to mortality in fishing operations and unsustainable exploitation. Therefore, it is classified as Near Threatened.

Population justification
The world population has been estimated at 40,000 individuals (E. Frere in litt. 2007). The breeding population includes 17,600-18,300 mature individuals in the Pacific from Isla Foca, Peru, to Punta Elefante, Peninsula de Taitao, Chile, with 1,800-2,000 breeding birds in the Atlantic from Bahia Sanguinetto to the Monte León National Park, Santa Cruz province, Argentina, and occasionally some individuals to the strait of Magellan (Zavalaga et al. 2002; Frere et al. 2004, 2005; Millones et al. 2015).

Trend justification
El Niño-driven declines have drastically reduced Peruvian populations, and the species has shown reported declines of 18% on the Atlantic coast in Argentina. However, the sizeable southern populations appear to be relatively stable (Frere et al. 2004) and hence an overall decline of 20-29% over three generations (c. 26 years) is suspected.

Distribution and population

Phalacrocorax gaimardi occurs on the coasts of southern South America: 17,600-18,300 breeding birds are found in the Pacific from Isla Foca, Peru, to Punta Elefante, Peninsula de Taitao, Chile, with1,800-2,000 breeding birds in the Atlantic from Bahia Sanguinetto to the Monte León National Park, Santa Cruz province, Argentina, and occasionally some individuals to the strait of Magellan (Zavalaga et al. 2002; Frere et al. 2004, 2005; Millones et al. 2015). Populations have declined, particularly in Peru (Frere et al. 2004). A series of surveys in Peru in 1999-2000 estimated the population to number 1,518-2,082 birds, and reported declines of up to 97.9% (3,229 to 69 birds) at ten localities in northern and central Peru between 1968 and 1999-2000, declines of 97.6% (2,230 to 54 birds) in the Chinchas and Ballestas islands between 1978 and 1999-2000, and declines of 72.6% (580 to 159 birds) at eight southern localities between the first half of the 1990s and 1999-2000 (Zavalaga et al. 2002). In Chile, surveys during 1998-2000 produced an estimate of 5,018-5,218 breeding pairs distributed along 40 breeding sites (Frere et al. 2004). Then, during 2010-2012, 10 unsurveyed sites were described and the known population increased to 8,193-8,393 breeding pairs (Barros et al. 2014). Although El Niño Southern Oscillation (ENSO) events may have led to distributional changes (with southern regions having become particularly important for the species), the population declines reported in Peru do not seem to have been mirrored in Chile (Frere et al. 2004). In Argentina, breeding populations are found in 13 localities of Santa Cruz Province, and about 93% of this population breeds near coastal cities (Gandini and Frere 1995; Frere et al. 2005), where coastal development is increasing rapidly (Gandini and Frere 1995). Between 1990 and 2002 the breeding population of Argentina showed a declined of 32% (Millones et al. 2015). However, during the last 10 years the Argentinian breeding population showed a moderate increase, reaching nowadays the abundance of early 1990s (Frere and Millones pers. comm.). The world population is now estimated at 40,000 individuals (Frere in litt. 2007). Continued population declines may lead to this species being uplisted to Vulnerable. 

Ecology

It favours rocky coastline with cliffs for nesting and shallow cold productive offshore waters for feeding. It nests in inaccessible areas rather than the tops of rocky islets, sometimes in loose aggregations approaching colonies. It is generally solitary when feeding, but may occur in flocks. Red-legged Cormorants are inshore feeders (less than 3 km from the colony) and forage in shallow waters (<15 m) on benthic fish and invertebrates (Frere et al. 2004). Often found coexisting with Rock Shags Leucocarbo magellanicus, sharing the same cliffs but not mixing nest sites, its breeding success is shown to increase with this sympatry (Millones et al. 2008), and it also has been recorded to breed sympatrically with Imperial Shags Leucocarbo atriceps (Millones et al. 2008). Avian predation of eggs and wind exposure at nest sites are important factors influencing chick mortality, with studies showing highest densities of active nests in areas protected from prevailing wind conditions (Millones et al. 2008).

Threats

Most threats to this species result from interactions with fisheries; both directly through entanglement in equipment and the collection of adults, chicks and eggs at a subsistence level, and indirectly through competition with fishermen targeting the cormorant’s prey species. The unintentional effects associated with large-scale fishing are likely to have an important influence on patterns of abundance and diversity of rocky intertidal shore communities (Frere et al. 2001). Targeted bird-hunting appears to be infrequent, but accounts of large number of birds killed in each hunting event suggest this may still pose a serious threat to local colonies; a group of fishermen from Carelmapu, Chile captured around 300 Red-legged Cormorants in a single hunting trip (Frere et al. 2004). High levels of shellfish and kelp extraction could affect trophic relationships in inter-tidal and benthic communities, reducing the availability of prey to Red-legged Cormorants. Likewise, the increase in legal and illegal utilisation of inshore waters, for scallop and other shellfish aquacultures may alter and reduce important feeding grounds through pollution and disturbance (Zavalaga et al. 2002).

The species is detrimentally affected by El Niño Southern Oscillation (ENSO) events. Effects have been particularly prominent in Northern Peru where dramatic population declines have been recorded in conjuncture with elevated sea surface temperatures, kelp die-off and reduced marine productivity. High mortality (Apaza and Figari 1999), lack of reproduction (Paredes and Zavalaga 1998) and dispersal (Jahncke 1998) all contributed to population declines. In Zavalaga et al.’s 2002 study, a remarkable low proportion of juveniles (5%) was recorded, a likely testimony to the adverse effects on breeding success and/or post-fledgling survival during the 1997/98 El Niño.

Egg predation by gulls is an important mortality factor for this species. Egg mortality is considerably higher at Isla Elena, Argentina, where the number of predators (Kelp Gulls Larus dominicanus and Dolphins Gulls Larus scoresbii) is higher (Fere and Gandini 2001). Predation pressures may be increasing as a high proportion of the population breeds near coastal cities where intense fishing activity, harbour traffic and increased amounts of urban and fish waste is believed to favour its main predator, L. dominicanus (Fere et al. 2004, Millones et al. 2015).

Conservation actions

Conservation Actions Underway
Chile is discussing the creation of a network of marine protected areas along its coastline. Peru and Argentina are improving their coastal marine protected areas network.

Conservation Actions Proposed
Support the proposal to establish a network of marine protected areas along its geographic range. Assess the impact of the proposed industrial harbour in Argentina and recommend appropriate action. Monitor populations to identify changing trends, particularly in Chile and Peru. Research ways to minimise fisheries interactions. Identify and monitor key sites for the species, and aim to establish these as marine protected areas. Determine levels of hunting and bycatch in various parts of its range. 

Identification

71-76 cm. A grey shag. Head, neck, back, wings and tail all dark grey with feathers of upper back, scapulars and wings bearing silver grey sub-terminal markings bordered by black tips. Underside paler with a whitish throat and cheeks. Bill yellow orange and face reddish. Eye green. Legs and feet coral red. Juveniles occur in several morphs but generally brownish above, paler below with gular patch dark. Legs orange or dark-coloured. Similar spp. Unmistakeable.

Acknowledgements

Text account compilers
Moreno, R., Pilgrim, J., Sharpe, C.J., Bird, J., Anderson, O., Butchart, S., Benstead, P., Fjagesund, T., Lascelles, B., Martin, R., Miller, E.

Contributors
Frere, E., Millones, A., Gandini, P.


Recommended citation
BirdLife International (2019) Species factsheet: Poikilocarbo gaimardi. Downloaded from http://www.birdlife.org on 20/09/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/09/2019.