Chungungo

Description:

Marine otters (chungungos) are relatively small among otters, only the oriental small-clawed otter is smaller. However the latter species inhabits freshwater sites; thus the marine otter is the smallest exclusively marine mammal on Earth. Lengths range from 83 to 113 centimetres (33 to 44 in), not counting the tail of 30 to 36 centimetres (12 to 14 in). Weights can range from 3 to 5.8 kilograms (6.6 to 12.8 lb). Their fur is dark brown on the back and light brown on belly. The front and hind paws are webbed.

Habitat:

The Marine Otter is distributed along the southern Pacific Coast of South America from Chimbote (9°S) in northern Peru (Valqui 2012), to Isla Grevy (56°S) at the southern tip of Chile (Sielfeld 1997) and eastwards to the Isla de los Estados (54°S), in Argentina (Parera 1996). In 1964, Schweigger reported Lontra felina up to the Isla Lobos de Tierra (6° 26'S) in northern Peru. Studies of the last decades registered the northern range limit at Chimbote (9°S) (Brack 1978, Brownell 1978, Larivière 1998, Apaza et al. 2004, Sánchez and Ayala 2006, Valqui et al. 2010). Recent sightings in Huanchaco (8°S) suggest at least occasional events of recolonization north to the actual northern limit of distribution range, yet reasons for appearance or disappearance in these areas remain unclear (Alfaro-Shigueto et al. 2011). In the south the species´ presence is unclear in the XVth, Ist, XIth and XIIth regions and in the Tierra del Fuego region in Argentina (Cassini 2008). Although Redford and Eisenberg (1992) stated that “The original range of Lontra felina has decreased considerably because of excessive hunting in the past decades“, the authors do not mention any specific regions or study cases. Brownell (1978) stated that ”the species has been nearly exterminated from the regions of Cape Horn and southern Tierra del Fuego” but several works (Sielfeld 1989, 1990, 1992; Sielfeld and Castilla 1999) reported the species' presence between 49°S (Puerto Orella) and 55°S (Isla Grevy). The Marine Otter´s habitat is naturally fragmented in a very heterogeneous alternation of suitable habitat (rocky shore patches with caves or, sometimes, docks, shipwrecks or abandoned fishing boats) and unsuitable habitat (sandy beaches or rocky shoreline without caves). Thus, Marine Otters may be absent in several hundreds of kilometres of coast throughout the species´ total distribution range (Redford and Eisenberg 1992, Vianna et al. 2010, Valqui 2012). Lontra felina is the only species of the genus Lontra that is found exclusively in marine habitats. It uses coastlines with range extending approximately 30 m inland and 100-150 m of sea offshore (Castilla and Bahamondes 1979). The species inhabits marine areas exposed to heavy seas and strong wind (Cabello 1978, Ostfeld et al. 1989) and prefers rocky shores with caves that are above water at high tide, as well as areas with large algae communities offering a wide abundance and diversity of prey species (Castilla and Bahamondes 1979). Sandy beaches offer marginal habitat (Sielfeld 1989) and typically are used only for travel between dens and water (Ebensperger and Castilla 1992). Marine Otters are, for the most part, restricted to marine waters, but may occasionally travel up freshwater rivers in search of prey (Brownell 1978, Cabello 1978, Redford and Eisenberg 1992). Because not all coastlines are suitable, marine otters are found in disjunct populations throughout their distribution range (Redford and Eisenberg 1992). The fact that Marine Otters are solitary or only gathering in small groups suggests high ecological requirements regarding space. The species' preference for coastal waters offering a wide abundance and diversity of prey species (Castilla and Bahamondes 1979) is in conflict with the increasing artisan and industrial fishing effort. Marine Otters are top predators with a high metabolic rate, thus pollution of their environments may affect them more than other species, as their position in the food chain leads to high bioaccumulation of heavy metals, pesticides and other toxic elements. The Marine Otter diet is composed mostly of invertebrates, including crustaceans (decapods, shrimps, and crabs) and molluscs (bivalves and gastropods), and vertebrate prey, including fish from the families Blennidae, Cheilodactylidae, Gobiesocidae, and Pomacentridae, and occasionally birds and small mammals (Cabello 1978, Castilla and Bahamondes 1979, Ostfeld et al. 1989, Sielfeld 1990). Along the Valdivian coast in the south of Chile the diet of marine otter consisted of 25 species; 52% (13/25) of the species identified were crustaceans, 40% (10/25) were fish, and 8% (2/25) were molluscs. Crustaceans were found in 78% of 475 spraints, 100% of 929 prey remains, and 90.8% of prey determined by direct observation, fish in 20% of spraints and 9.0% of prey determined by direct observation, and molluscs in 2% of spraints and 0.2% of prey determined by direct observation. Observed seasonal variation in prey availability was reflected in the otter diet. Fourteen prey species were trapped; 43% (6/14) were crustaceans and 57% (8/14) fish, crustaceans were 93% of 566 trapped individuals, fish 7%. L. felina showed opportunistic feeding behaviour, selecting prey seasonally according to their availability rather than to their energy input (Medina-Vogel et al. 2004). Some studies have found that fruits (Greigia sphacelata, Fascicularia bicolor) may also be consumed on occasion (Brownell 1978, Cabello 1978, Medina 1995). Marine Otters may compete with gulls (Larus) and the South American Sea Lion (Otaria flavescens) for similar species of prey fish (Cabello 1978). The most important natural predator of the Marine Otter is the Killer Whale (Orcinus orca; Cabello 1978), but adults also may be killed by sharks (Parera 1996) and birds of prey may capture juveniles when on land (Cabello 1983). The Marine Otter is most likely a monogamous species. Mating typically occurs during December or January (Cabello 1978) with gestation of 60-65 days (Housse 1953, Sielfield 1989). Parturition usually occurs from January to March. It takes place in a den or on shore between rocky outcroppings and vegetation. The litter size varies from two to four young, with two being observed most frequently. Young Marine Otters remain with their parents for approximately ten months. Adults transport their young by carrying them in their mouths or resting the young on their bellies as they swim on their backs. Both adults in the monogamous pair bring prey back to the den to feed their young (Parera 1996). When not breeding, Marine Otters are mostly solitary. The group size is seldom more than two to three individuals. Its activity pattern is generally diurnal, with peaks of activity noted in early morning, mid-afternoon, and evenings. Marine Otters are much more agile in the water than on land

Notes:

The Marine Otter is confirmed as Endangered on the basis of inferred future population decline due to habitat loss and exploitation. The Marine Otter has a restricted distribution along the Pacific coast from northern Peru along the Chilean coast to Cape Horn and Isla de Los Estados in Argentina. It is patchily distributed from Peru to Tierra del Fuego. Its distribution north of 39°S latitude is becoming highly fragmented because of exploitation, pollution and increased human occupation along the seashores. Poaching is still present in many regions, especially south of 39ºS latitude, where there is little or no enforcement of protective legislation. The greatest threats to its continuous existence are accelerating habitat destruction, degradation, and competition for prey, accidental kill in crab pots and poaching throughout the range. The original range of Marine Otter has decreased considerably because of excessive hunting (Redford and Eisenberg 1992), and the species has been nearly exterminated from the regions of Cape Horn and southern Tierra del Fuego (Brownell 1978) as well as from the northern extremities of its former range (Chehebar 1990). Additionally, Marine Otters are persecuted and killed directly for alleged damage to local fish, bivalves, and shrimp populations (Miller et al. 1983, Redford and Eisenberg 1992, Apaza et al. 2004).) Illegal fishing techniques (e.g. dynamite fishing, accidental death by entanglement (bycatch) in fishing nets) are a frequent problem in several localities of the Peruvian coast, such as Huarmey (Valqui 2012) and Paracas (Apaza et al. 2004, Valqui 2012). Pollution of the Marine Otter's habitat comes from several centres of industrial fishing activity like Chimbote (probably the most important fishing port at the Peruvian coast) and mining cities Ite, Ilo and Marcona in Peru, where tailings have been spilled directly into the ocean for over 40 years, altering several kilometres of the littoral (Apaza et al. 2004). A common denominator for all regions is that there is very law enforcement regarding the Marine Otter´s conservation status and protection, as hunting or killings on fish farms do not implicate consequences to the offenders. Global natural factors like the El Niño Southern Oscillation (ENSO) also may considerably affect the marine otter population (Vianna et al. 2010), due to the more or less drastic climatic and oceanographic changes that cause the mortality of several marine communities from fish to mammals (Apaza and Figari 1999, Wang and Fiedler 2006). These threats are inferred to result in future population reductions of at least 50% over the next three generations (30 years Pacifici et al. 2013) unless conservation measures are strengthened.