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Article

Habitat Selection of Sympatric Lontra felina and L. provocax in Chilean Patagonia: Toward Sustainable Management

by
Walter Sielfeld
1,
Claudia Bunster
1,
Jonathan A. Guzmán
2,*,
Marx Buscaglia
1,
Laura Sánchez Jardón
1,
Arturo Clark
1 and
Raúl Briones
3
1
Centro Universitario, Universidad de Magallanes, sede Regional Coyhaique, José Miguel Carrera 485, Coyhaique 5951380, Región de Aysén, Chile
2
Escuela de Educación, Departamento de Ciencias Básicas, Universidad de Concepción, Campus Los Ángeles, Juan Antonio Coloma, Los Ángeles 4451032, Región del Biobío, Chile
3
Bioforest S.A. Program Wildlife Conservation, Km 15 Camino Coronel, Concepción 4360000, Región del Biobío, Chile
*
Author to whom correspondence should be addressed.
Sustainability 2025, 17(18), 8290; https://doi.org/10.3390/su17188290
Submission received: 24 June 2025 / Revised: 25 July 2025 / Accepted: 19 August 2025 / Published: 15 September 2025
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Abstract

Understanding habitat use in sympatric species is key to informing conservation efforts. Lontra felina and L. provocax are semi-aquatic mustelids commonly known as South American marine and southern river otters, respectively, that occupy contrasting coastal environments in southern Chile. We investigated habitat characteristics associated with sightings of both species in the Raúl Marín Balmaceda Multiple Use Protected Area, northern Chilean Patagonia. Our results show L. felina is restricted to exposed, steep rocky shores with sparse vegetation and intertidal belts dominated by Durvillaea antarctica and Lessonia spp., while L. provocax was found to be associated with sheltered, forested margins and estuarine areas dominated by Macrocystis pyrifera and other meadow-forming algae. Records did not show coexistence of both species in the same location; therefore, it is concluded that they exhibit a sympatric but non-syntopic pattern.

1. Introduction

Otters are aquatic mammals broadly distributed across tropical to cold temperate regions [1]. While most species primarily rely on freshwater environments, several also inhabit marine coasts to varying degrees [2,3,4]. Among the most fully marine-adapted are the sea otter (Enhydra lutris) and the South American marine otter (Lontra felina), both of which have evolved specialized traits to thrive in coastal ecosystems [3,4]. In Chile, two otter species coexist: the marine otter (L. felina), locally known as “chungungo”, and the southern river otter (L. provocax), or “huillín” [5].
L. felina inhabits the Pacific coastline from northern Peru to Cape Horn, with isolated populations also reported in Argentine Patagonia [6,7,8]. As part of the rocky shore community [9,10], its persistence depends on habitat connectivity, shelter availability, and the structure of littoral vegetation [11]. Notably, this species shows considerable ecological plasticity, even venturing inland under certain conditions [12]. L. provocax, in contrast, is a more cryptic species historically restricted to freshwater systems in southern Chile and Argentina [13,14,15]. However, it is also found in marine-influenced habitats such as estuaries, fjords, and channels in southern Patagonia [6,16].
In such transitional environments, both species may occur within overlapping ranges, though their behavioral and ecological interactions remain poorly understood, mainly because no conclusive studies have addressed the interactions between both species. This is principally due to sympatric conditions being restricted to the Patagonian archipelago, an area that is highly inaccessible for research development. Some authors [16,17] have suggested a potential spatial segregation to reduce interspecific competition, but trophic overlap and competitive interactions have yet to be demonstrated conclusively.
In a few areas of the world, it is possible to investigate two species of otters occurring in the same geographic area [18]. Habitat and food niche overlap have been studied for coexisting neotropical Lontra longicaudis and Pteronura brasiliensis, Enhydra lutris and Lontra canadensis in the Eastern North Pacific [19], habitat selection by Lutreogale perspicillata, Lutra lutra and Aonyx cinereus in India [20,21], Lutra lutra, Lutra sumatrana and Aonyx cinereus in Sumatra, Indonesia [22], and sympatry of Lontra provocax and L. felina in Chiloé Island, Chile [23]. If these species occupy same or overlapping geographic areas, they are said to be sympatric [21] and if they also occupy the same specific habitat or microhabitat within that area (meaning they are found living side-by-side and utilizing the same resources) they are considered syntopic. This term highlights a particularly close degree of co-occurrence compared to broader sympatry, where species might overlap geographically but not necessarily share the exact same living space.
In Lontra felina and L. provocax despite sharing morphological similarities and a close evolutionary history—having diverged relatively recently during the Pleistocene [24] they exhibit distinct habitat preferences often associated with different degrees of wave exposure, shoreline granulometry, and the presence or absence of littoral forest [16,25,26,27,28]. The Pleistocene divergence let to a L. felina adapted to the strong wave exposed Pacific coast of Peru and Chile, south to Cape Horn, and L. provocax adapted to wave protected coasts of rivers, lakes, fjords and channels of Southern Chile and Argentina [29]. With the retreat of the last ice age L. provocax may have initiated its invasion of the wave sheltered interior channels and fjords of the Patagonian archipelago [29]. This gives rise to situations of coexistence of both species in the same area as has been described previously [30].
L. felina favors exposed rocky coasts with sparse or stunted vegetation, while L. provocax is more closely associated with riparian forest and sheltered estuarine systems. These contrasts suggest a process of ecological segregation that may help reduce interspecific competition where both species co-occur [17,30] and highlight their respective vulnerabilities to environmental pressures.
Conservation concerns are critical for both species, which are currently listed as “endangered” [31,32]. Their population declines are linked to various human-induced pressures, including loss of riparian vegetation, degradation of river mouths and estuaries, and the growing extraction of coastal resources such as brown macroalgae, fishes and shellfish. These impacts are particularly acute in areas where aquaculture infrastructure overlaps with otter habitat, a concern especially relevant in fjords systems of southern Chile.
L. provocax has already disappeared from a large portion of its northern historical range, being considered “extinct” in central-southern Chile (34°–37°30′ S) [13] because of contamination, habitat loss and intervention in river basins. This situation is of major concern that has not received due attention, and there is no guarantee that similar declines in otters will not occur further south if anthropogenic pressures persist.
Given the role as top predators of L. felina and L. provocax within the kelp forest and estuarine ecosystems feeding on fish, crustaceans, echinoderms, and littoral mollusks [6,7,11,24,25,33,34,35,36,37,38,39,40], their conservation is essential for maintaining the ecological integrity of southern Chile’s coastal landscapes. In this context, understanding the habitat preferences and distribution patterns is essential for planning effective conservation measures of otters [20].
This study aimed to investigate the characteristics of the habitat used by the sympatric species Lontra felina and L. provocax within a coastal–estuarine mosaic in Northern Chilean Patagonia. The central question was whether these species coexist by sharing the same habitat types, or whether they exhibit spatial segregation due to differing habitat preferences.
This information will be of great importance for the protection of the otter species once the Management Plan (designed for the study area designated as a Multiple Use Marine Protected Area) is implemented by regional authorities. Therefore, this study had the following specific objectives: (1) To identify sites with the presence of L. felina and/or L. provocax; (2) To characterize the habitat of sites with otter records; (3) To compare habitat use between otter species to explain their local distribution; (4) To generate baseline information to support otter habitat protection and to guide the mitigation of human disturbances associated with the activities outlined in the Management Plan established by Chile’s Ministry of the Environment (Ministerio del Medio Ambiente) for the Multiple-Use Coastal Marine Protected Area (MCPA), which includes the study area.

2. Materials and Methods

2.1. Study Area and Period

The area was selected for the following reasons: (i) The existence of previous reports confirming the presence of both otter species in the area [30]; (ii) Relatively easy access to the area and the availability of operational infrastructure for research; (iii) Very low levels of human disturbance, except around the village of Raúl Marín Balmaceda; (iv) Significant logistical difficulties in accessing other comparable sites where both otter species occur, as these are in more remote areas; (v) Since 2015, the area has been protected as a Multiple-Use Coastal Marine Protected Area (MCPA). Its micro-zoning, established by the Ministry of the Environment [41], includes zones designated for aquaculture (salmon farming), shellfish harvesting, recreation and tourism, human settlement, and three areas specifically for biodiversity conservation; (vi) Given the imminent increase in human activity associated with these uses, a stronger baseline is needed to assess and mitigate potential impacts on otter populations.
Surveyed sectors included: Palena River, Coca Peninsula, Las Hermanas Islets, Los Payos, Paijas Islets, Bahía Mala Estuary, Refugio River, Santo Domingo Estuary, and the Añihue River (Figure 1). Fieldwork was performed aboard the L.M. “Chelo” (15 m in length), supported by a 3 m pneumatic boat. Surveys were carried out on the following dates and sectors: 8–10 November 2021 (Huala Point, Los Patos); 29 October to 4 November 2021 (estuarine sector of Pitipalena and Rodríguez River); 2–9 February 2022 (Garrao Channel, Las Hermanas Islets, Añihue River, Mala Bay, Los Payos); 25 February to 3 March 2022 (Las Hermanas islets); 21–28 March 2022 (Refugio Channel, Melipichún Point, Crujul Islet); 28 April to 4 May 2022 (Santo Domingo, Guaquel Islands, Refugio Channel); and 4–9 May 2022 (Larga islands, Guaquel Islands). For sector names see Figure 1. Data from 2016 and 2019, based on previous work carried out in the sector were also added (see Table 1).
No evidence suggests that L. felina and L. provocax exhibit seasonal variation or migratory behavior. However, they may occasionally shift feeding or denning sites within established territories. For the purposes of identifying and characterizing otter habitat sectors, individuals observed during 2016–2022 dataset were considered to be resident in the areas where they were repeatedly recorded.
The study area corresponds to a “Puyuhuapi evergreen forest” formation, part of the “inland temperate evergreen forest of Nothofagus nitida and Podocarpus nubigena” [44]. In insular sectors, which are mainly coastal and highly exposed to ocean waves, vegetation corresponds to “temperate coastal evergreen scrub” composed of Pilgerodendron uvifera and Nothofagus nitida. This vegetation is typical of the oceanic islands of the western Los Chonos Archipelago and includes formations like “Oceanic evergreen scrub and peatlands” and “Messier Channel Evergreen Scrub”.
Depending on wind and tide exposure, slope, and coastal granulometry, the following situations were defined:
Ecosystems associated with fjords
-
Coastal edges protected from wind and tide, dominated by zonal vegetation that sometimes completely covers the shoreline.
-
Coastal edges are exposed to wind and tide, with shrubby and herbaceous vegetation characterized by species such as Escallonia rubra, Fuchsia magellanica, Gunnera tinctorea, G. magellanica, Acaena ovalifolia, Blechnum chilense, Asplenium obtusatum, and Fascicularia bicolor.
-
Coastal dunes found at estuary mouths of the Palena, Bahía Mala, and Santo Domingo Rivers, with high cover of Fragaria chiloensis, and terraces of variable width dominated by grasses, Cyperaceae, and Juncaceae.
Ecosystems associated with the marine coast
The intertidal and shallow subtidal zones include extensive kelp beds of brown macroalgae [45,46,47,48,49,50,51,52]. Near river mouths (Palena, Rodríguez, Añihue, Refugio Rivers), Santo Domingo estuary and Bahía Mala, the rocky coastline is interrupted by estuarine environments and sandy beaches. There, the following sectors were defined:
-
Intertidal: The most exposed areas feature belts of Durvillaea antartica and Lessonia spicata [53,54,55].
-
Subtidal: In more sheltered channels and inland waters, beds of Macrocystis pyrifera (syn. M. integrifolia) are present, often associated with Lessonia trabeculate [56,57].

2.2. Wave Exposition

Exposed rocky shores face directly into oceanic waves and breakers and show a Durvillaea antartica and Lessonia berteroana/spicata intertidal belt and Lessonia trabeculata/Macrocystis integrifolia/pyrifera subtidal belt, with an associated invertebrate and vertebrate community. The strong waves generate an important up and down of sea level and abundant water splash.
The interior channels of the Patagonian archipelago are characterized by extensive Macrocystis integrifolia/pyrifera subtidal kelp beds [58,59,60,61]. Waves, when present, are locally wind driven, normally no splash, in the water column frequently an upper layer of low salinity, resulting from strong and heavy rains and from meltwater from the Patagonian Icefields. On the shoreline, there is only tidal rise and fall.
A semi-exposed category was first recognized before for rocky shore of Valparaiso [62], not directly exposed to the oceanic waves of the Pacific. In these conditions only Lessonia berteroana/spicata persist in the intertidal, with changes in the associated invertebrate community. There is no splash; the oscillatory effect of the oceanic waves is weak, but perceptible.
In North Patagonian channels (Chiloé and Aysén) and South Patagonian channels (Magallanes) the oceanic waves hit the western coastline of the most exterior islands (strong exposed sites), to then enter weakening through the Gulfs (Coronado, Corcovado, de Penas, Ladrillero, Trinidad, etc.) and to the west opening channels (Chacao, Moraleda, Fallos, Trinidad, Concepción, etc.), also the west entrance of the Magellan Straits, giving rise to such an intermediate situation. In these conditions persist an intertidal Lessonia belt, but Durvillaea antartica is absent, and the coastal extension can reach several km. In these cases, the category is a valid one, representing in surveys in Magallanes [29,63] the western distribution limits of L. provocax inhabiting in the interior channels and eastern penetration limits of L. felina inhabiting the oceanic exposed coast. In the study area of Raúl Marín (this article) this category characterizes the north entrance of the Canal Refugio and eastern coast of Isla Refugio, and Los Patos sector.

2.3. Oceanography

The study area opens to the west to the Corcovado Gulf, a marine sector with oceanic influence, and to the east to an estuarine sector associated with the Rodríguez/Palena Rivers and the Brazo Pillán system. The oceanic influence penetrates southwards towards the Refugio Channel and gradually weakens until the Guaquel Islands. Sectors strongly exposed to ocean waves are indicated in orange in Figure 1. According to oceanographic data of the area [41,64,65], the water column shows a stratification gradient transitioning from the marine domain toward the headwaters of the estuarine system [65,66]. The reported temperature and salinity for the marine sector are 15–16 °C and 20 PSU at 2 m depth and 13–14 °C and 26–27 PSU at 8 m depth, and for the estuarine sector, 14.5–16 °C and 10–20 PSU at 2 m depth and 12.5–13.5 °C and 26–30 PSU at 8 m depth.
The marine and estuarine sectors are shallow with depth ≤100 m (Nautical Chart 08211, Hydrographic Institute, Chilean Navy). Depths at otter sighting places is ≤15 m.

2.4. Climate and Rainfall

The Aysén Region is part of the Valdivian Ecoregion with a cold hyper-oceanic climate with low temperatures, strong winds and abundant rainfall [44]. At Raúl Marín Balmaceda the total annual precipitation is of around 3700 mm, a monthly fall of 210–440 mm, May to August being the rainiest months [41].

2.5. Otter Species Identification and Records

Surveys followed the “Standard Method” recommended by the IUCN SSC Otter Specialist Group [67]. Species were identified visually based on body size, coloration, behavior, and particularly muzzle morphology, traits consistently cited as reliable diagnostic characters [5,6,29,63,68,69] (Figure 2). Behavioral differences further supported identification: Lontra felina is typically bolder and more tolerant of human presence, while L. provocax is elusive and markedly shy. All records were based exclusively on direct sightings of individuals (either on land or in water). Indirect signs (e.g., dens, feces, or tracks) were recorded separately and stored.
Importantly, species identification in this study was based not only on established diagnostic traits, but also on extensive regional expertise. The first author of this manuscript (WS) has over four decades of field experience and has made substantial contributions to the knowledge of Lontra felina and L. provocax through a series of studies on their morphology, behavior, and distribution. While some of these works were published in regional journals, they remain key references in the field. His authorship of Los Mamíferos Marinos de Chile (Universidad de Chile, 1983), a foundational and widely cited reference [5], further supports the credibility of the species identification provided in this study.
Each field campaign lasted 5–6 days. Three to four days were devoted to prospecting the marine sector and the estuarine sector. Fieldwork was performed aboard the L.M. “Chelo” (15 m in length), supported by a 3 m pneumatic boat, from 09:00 to 17:00 to ensure good lighting conditions. The survey consisted of exploring the coastal edge of the study area at a distance of 10–50 m and looking for otter presence. In each case of positive sightings, a site characterization was carried out. The survey type consisted of navigation with a boat, 10–50 m, from the shoreline (depending on depth, presence of kelp beds, waves, etc.).
Observations of the shoreline were conducted from the boat by four observers, utilizing binoculars (10 × 50) and photography. No animal handling or invasive procedures were conducted during this study.
During adverse weather conditions (Beaufort scale 4–5) wind and wave exposed sectors were avoided and the prospection was shifted to more wind and wave sheltered sectors. Tidal cycles were not considered when planning field work.
The escape distance of Lontra provocax and L. felina normally permits visual identification with binoculars and adequate pictures with 300 mm tele objective lens. If species identification was not possible, the sightings were not included in the dataset.

2.6. Handling of Data from Different Sources

Previously published and georeferenced records for the Bahía Islas sector (Los Payos Islands and Velasco Islands) [30] and records of L. felina for Las Hermanas Islets, Islote Alleupa, Punta Huala, and Punta Piti [42] were included in this study (Table 1). Additionally, evidence from residents (photos and videos) for Las Hermanas Islets, Ensenada de las Islas and Canal Refugio were classified by habitat attributes.
Residents of Raúl Marín Balmaceda village are involved in “citizen-based monitoring” of local biodiversity, promoted by the Ministry of the Environment of Chile through government initiatives. This included two training programs directed to local habitants:
  • 2020–2022: Turismo de Mamíferos Marinos, Oportunidad de Conservación y Desarrollo”, Gobierno Regional de Aysén, Fondo de Innovación y Competitividad (FIC).
  • 2024–2025. Monitoreo ciudadano de fauna marina en el Área de Conservación de Múltiples Usos Pitipalena Añihue, FAO/PNUD-GEF Gobernanza Marítima.
The marine mammal training program (including otters) was led by the first author of this article (WS) and based on the methodology approved by the Chilean National Fisheries Service [70]. This approach was developed in response to the import previsions of the U.S. Marine Mammal Protection Act 2021, which apply to the List of Foreign Fisheries (LOFF) that includes Chile [71].

2.7. Habitat Characterization

Habitat use was defined as “a place with appropriate conditions for an organism, species or community to live” [72]. Microhabitat refers to landscape elements associated with individuals, and mesohabitat refers to the larger landscape unit or ecosystem [73,74]. Habitat characterization involved classifying each site where L. felina and/or L. provocax were observed [75]. A pictorial guide of attributes is shown in Figure 3 and Figure 4.
For the present purposes seven variables (habitat attributes) were assessed, some of which have already been used in similar work with Lutra lutra [76,77], Lutra perspicillata [78], Lontra longicaudis [79] and Pteronura brasiliensis [18].
The following variables were assessed:
Attribute 1, Wave exposure: (1) Exposed: directly impacted by Pacific Ocean waves and saline spray from the Corcovado Gulf. (2) Sheltered: located in bays, inlets, and channels, influenced by tides. (3) Semi-exposed: intermediate, leeward situations with tidal variation but minimal direct wave impact.
Exposed rocky shores face directly into oceanic waves and breakers, with a Durvillaea antartica and Lessonia berteroana/spicata intertidal belt and Lessonia trabeculata/Macrocystis integrifolia/pyrifera subtidal belt, along with an associated invertebrate and vertebrate community. The strong waves generate water turbulence, significant vertical fluctuation of sea level and abundant splash.
The interior channels of the Patagonian archipelago are characterized by extensive Macrocystis integrifolia/pyrifera subtidal kelp beds [58,59,60,61]. Waves when present, are locally wind-driven, normally no splash, in the water column frequently an upper layer of low salinity coming from strong and heavy rains and from meltwater from the Patagonian Icefields. On the shoreline, only tidal up and down.
A semi-exposed category was recognized before [62] for the rocky shore of Valparaíso, not directly exposed to the oceanic waves of the Pacific. In these conditions only Lessonia berteroana/spicata persist in the intertidal, with changes in the associated invertebrate community. There is no splash, the up and down effect of the oceanic waves is weak, but perceptible.
In North Patagonian channels (Chiloé and Aysén) and South Patagonian channels (Magallanes) the oceanic waves hit the western coastline of the most exterior islands (strong exposed sites), then enter gradually weakening through the Gulfs (Coronado, Corcovado, de Penas, Ladrillero, Trinidad, etc.) and to the west opening channels (Chacao, Moraleda, Fallos, Trinidad, Concepción, etc.), also the west entrance of the Magellan Straits, giving rise to such an intermediate situation. In these conditions an intertidal Lessonia belt persists, but Durvillaea antartica is absent, and the coastline extension can reach several km. In these cases, the category is a valid one, representing in surveys in Magallanes [29,30,63] the western distribution limits of L. provocax inhabiting in the interior channels and eastern penetration limits of L. felina inhabiting the oceanic exposed coast.
In the present study area of Raúl Marín this category characterizes the north entrance of the Canal Refugio and eastern coast of Isla Refugio, and the Los Patos sector.
Attribute 2, Shoreline granulometry: classified by the Udden-Wentworth scale [80] as: silt (0.002–0.1 mm), sand (0.2–2.0 mm), fine gravel (2.0–6.0 mm), gravel (6.0–60.0 mm), cobbles (100–200 mm), boulders (200–1000 mm) and cliffs (>1000 mm). Otters were only found associated with cobbles, boulders and/or cliffs. The classification was performed by photointerpretation [81,82], supported by measurements taken directly in the field. In each place, 10 randomly selected stones were measured with a tape to assess granulometry.
Attribute 3, Coastal slope: the slope of the first 10 m inland from the high tide line was categorized as: ≥45° (cliffs) and <45° (stony beaches). Measurements were taken with an optical clinometer.
Attribute 4, vegetation type: based on floristic inventories, zonal types included, “Puyuhuapi evergreen forest” and “oceanic evergreen scrub”; azonal types included, “coastal dunes”, “coastal grasslands” and “shrub strips”.
Zonal vegetation is here considered primarily determined by climate, forming large-scale patterns across the region. Azonal vegetation is influenced more by local factors, such as soil type, topography, and water availability, often appearing in smaller, isolated patches regardless of the overall climate.
Attribute 5, vegetation physiognomy: categories result from different exposure to dominant winds and were documented in the field by eye estimation and photography:
(1) High normal forest (15–10 m); (2) Low normal forest: (5–10 m), (3) Wind-stunted Forest (2–5 m), (4) Herbaceous vegetation (<1 m), (5) Bare rock. For comparison purposes, these categories were adopted from the Forest Inventory of the South Patagonian Archipelago from AONKEN Consultants/National Forestry Corporation [83,84].
Attribute 6, vegetation cover at tidal line: by visual estimation directly on the field as (1) Shaded and forest-covered eulittoral (0 m uncovered), the shore line is completely covered by bushes, overhanging trees and trunks; (2) Sunny forest edge with a devegetated supratidal strip (1–5 m uncovered) outside the coastal forest; (3) Azonal herbaceous/grassy eulittoral (5–20 m platform with grass and herbs).
Attribute 7, Macroalgal forests: presence/absence of brown macroalgae belts in the otter habitats was recorded. Biotopes were defined as the following classifications for the Aysén area [85,86,87,88,89,90]: (1) Exposed oceanic coast: Durvillea antartica, Lessonia spicata with/without Macrocystis pyrifera, (2) Semi-exposed coast: Lessonia spicata and Macrocystis pyrifera; (3) Sheltered bays: subtidal M. pyrifera; (4) Estuarine biotopes: Gracillaria, Enteromorpha, Ulva. Macroalgal taxonomy follows [56,57,86,91]. Distribution was supported by [48,92,93,94]. These habitats also sustain biological communities that provide foraging opportunities for L. felina and L. provocax.
All subjective categories involving visual estimation, as well as species identification, were agreed upon by the four observers on board. Other physical variables-such as wind intensity and direction, tidal range, water and air temperature, salinity gradients and seasonal wave exposure-could not be considered due to the lack of available data at the micro and mesoscale level required for meaningful comparison among otter sites.
The study area extends approximately 33 km, from Punta Huala to Islotes Guaquel. The only settlement in the area is the village of Raúl Marín Balmaceda, with a population of approximately 265 inhabitants [41]. All other sectors are currently undisturbed and are here considered pristine.
Freshwater sources such as rivers and small streams are frequent due to the area’s constant rainfall. However, distance to freshwater was not considered relevant to the marine distribution of otters. Access to denning sites was also excluded as a variable, based on the assumption that the dense coastal primary and overmature forests, along with the rocky shoreline, provide a sufficient supply of suitable denning habitat for the local otter population.

2.8. Data Analysis

All data analyses were conducted using R Studio (v2024.04.2. Build 764) with language R (v4.2.2; R Core Team 2023) R Statistical Software Environment [95]. Principal Component Analysis (PCA) was selected as an appropriate exploratory method to summarize variation in habitat use based on the aggregated percentage occurrence of each otter species (Lontra felina and L. provocax) across the habitat attributes and categories listed in Table 2. Although other ordination approaches such as non-metric multidimensional scaling (NMDS) or correspondence analysis are common in ecological studies, PCA was chosen here because it is suitable for identifying linear relationships among continuous variables and allows for direct interpretation of species-habitat associations based on proportional data. Prior to analysis, data were standardized to ensure comparability between variables. The first two principal components explained 100% of the variance and were used to explore how habitat categories differ in relation to their association with each species. Additionally, a chi-square test of independence was conducted in R to evaluate the association between otter species and habitat categories (Table 2). Categories with zero counts for both species were excluded to meet test assumptions. To complement this analysis, Fisher’s exact test was applied to the shaded habitat, which showed the strongest deviation from expected frequencies.
A post hoc power analysis was conducted to evaluate whether the sample size was sufficient to detect a meaningful association between otter species and habitat categories. The analysis aimed to assess if the sample size was adequate to identify potential distributional differences between Lontra felina and L. provocax across the various habitat types recorded in the study.

3. Results

3.1. Species Presence and Distribution Patterns

Table 1 summarizes 28 georeferenced occurrence records of Lontra felina and L. provocax obtained between 2015 and 2022, including both new field data and previously published sources. L. felina was recorded in 15 sites (including 5 shared with L. provocax), while L. provocax occurred in 18 sites. The dataset includes a range of detection types (sightings, photos, videos) across estuarine, fjord, and exposed coastal environments in northern Patagonia, forming the basis for subsequent habitat and spatial distribution analyses.
The attributes of the sites where otters were detected show important interspecific differences. L. felina was principally found along wave-exposed oceanic coastlines, typically in sectors with steep rocky slopes and sparse or stunted vegetation. However, records also confirm its presence in semi-exposed and even protected estuarine areas, such as Raúl Marín Balmaceda and the Añihue sector (e.g., 43°52′21.1″ S, 73°00′56.2″ W), habitats typically used by L. provocax. Conversely, L. provocax was observed in wave protected sites, with the only exception being a single photographic record from the leeward (semi-protected) side of Las Hermanas Islets. No direct interactions (co-occurrence) between both species were documented at any site, even where L. felina ventured into estuarine areas preferred by L. provocax.
These patterns suggest a divergent distribution along the exposure gradient, probably as a result of different wave tolerance: L. felina appears adapted to high-energy shorelines with minimal canopy cover, while L. provocax relies on wave-protected and shaded environments with forested coastline. The absence of co-occurrence records reinforces the notion of distinct habitat use, likely mediated by wave exposure, littoral slope, and coastal vegetation (see Figure 1, Figure 3 and Figure 4 for spatial context).

3.2. Habitat Attributes of Sightings

Habitat conditions were characterized based on physical and biological variables detailed in the methodology, summarized in Table 2 and visually represented in Figure 1, Figure 3 and Figure 4. Lontra felina was observed in 100% of cases on cliffs or rocky walls, with 93.75% of records on slopes ≥45° (Table 2). Regarding habitat exposure, 37.5% of sightings occurred in highly wave-exposed zones, 18.8% in semi-exposed environments, and 43.8% in protected estuarine or coastal channels. Vegetation types included Puyuhuapi evergreen forest (62.5%, mostly stunted), coastal shrub strips (25%), and oceanic evergreen scrub (12.5%). In terms of shoreline coverage, 43.8% of sectors were entirely unvegetated, while 56.2% featured vegetated supralittoral belts, generally exposed to sunlight. Intertidal zones were dominated by Lessonia berteroana/spicata in 50% of records and Durvillaea antarctica in 37.5%. L. provocax, on the other hand, was recorded in 68.8% of cases on cliffs, 12.5% on boulder-dominated shores, and 18.8% on gravel or cobble zones, mainly near river mouths. All records were in wave-protected environments. Vegetation was present in 100% of sites, with low evergreen forest dominating (81.3%), followed by high forest (12.5%) and stunted or grassland forms (6.3%). Most shorelines (81.3%) were shaded by overhanging forest, with only 6.3% open to sunlight. Subtidal vegetation included Macrocystis integrifolia beds (56.3%) and Gracilaria–Enteromorpha–Ulva meadows (18.8%). No records were associated with Lessonia or Durvillaea intertidal belts. However, L. felina was more frequently associated with intertidal belts dominated by Durvillaea antarctica and Lessonia berteroana/spicata, while L. provocax showed higher occurrence in sites with Macrocystis integrifolia and Lessonia vadosa combinations.
A chi-square test of independence was performed to assess the association between otter species and habitat categories. The test yielded a χ2 value of 45.16 with 15 degrees of freedom and a p-value of 0.0000721, indicating a highly significant association (p < 0.05). Therefore, the null hypothesis was rejected, and it was concluded that Lontra felina and L. provocax are not randomly distributed across habitat types. The differences between observed and expected frequencies support the hypothesis that the two species exhibit distinct preferences for specific microhabitats or environmental conditions. To further explore this pattern, Fisher’s exact test was applied to the “shaded” habitat category, which showed the greatest deviation from expected values. The result was also statistically significant (p = 0.00002), reinforcing that L. provocax was more strongly associated with shaded environments than L. felina. A post hoc power analysis based on the observed chi-square test confirmed that the sample size (n = 161) was sufficient to detect a large effect (w = 0.53) with high statistical power (>0.99), supporting the robustness of the association detected between otter species and habitat categories.

3.3. Principal Component Analysis (PCA)

The PCA (Figure 5) synthesized habitat associations for both species using eight categorical and continuous variables. The first principal component (PC1) explained 71.5% of the total variance and was primarily driven by wave exposure, coastal slope, vegetation structure, and substrate type. The second component (PC2) accounted for 28.4% of the variance, capturing variation in forest physiognomy, shading, and microtopographic features. L. felina clustered along the strongly positive axis of PC1, indicating a clear preference for highly exposed coastlines with steep slopes (>45°), cliffs, and unvegetated or sunny supralittoral zones. These conditions reflect their specialization in wave-battered rocky shores and reduced vegetation cover, often associated with open access to marine resources. In contrast, L. provocax grouped on the opposite side of PC1, associated with sheltered coasts, dense riparian forest, shaded shorelines, and substrates composed primarily of boulders and cobbles. Its centroid aligned closely with protected or semi-protected shorelines, suggesting an ecological preference for more buffered environments typical of riverine or estuarine systems.
The biplot (Figure 5) showed no centroid overlap between the two species, confirming robust ecological segregation in multivariate space. The vectors representing habitat variables further illustrated divergent ecological requirements. Notably, several microhabitat conditions, such as stunted forest, grassy–herbaceous cover, and semi-exposed sites, appeared near the origin of the axes, suggesting transitional environments that are not preferentially selected by either species under current conditions.
Sites where L. provocax was recorded—mostly estuaries and sheltered channels—formed distinct clusters from those where L. felina was found, which were restricted to exposed oceanic shorelines. This pattern suggests that habitat segregation is reinforced not only by structural landscape attributes, but also by differences in prey communities likely shaped by salinity, wave energy, and vegetation.
Together, these findings offer strong quantitative support for spatial segregation between L. felina and L. provocax, reinforcing the hypothesis of niche partitioning and differential ecological requirements. These results have direct implications for conservation and spatial planning: while L. felina may benefit from the protection of exposed, cliffed coastal zones, L. provocax likely depends on the preservation of forested, low-energy shorelines—ecosystems particularly vulnerable to fragmentation and anthropogenic disturbance. These descriptive patterns are consistent with the results of the multivariate analyses (PCA), as well as with the categorical comparisons (chi-square and Fisher’s exact test), reinforcing the interpretation that L. felina and L. provocax show differentiated habitat use within the study area.

4. Discussion

The distributional patterns observed for Lontra felina and L. provocax (Figure 2) in the Raúl Marín Balmaceda Multiple-Use Marine Protected Area reflect different habitat attributes likely aligned with their respective evolutionary histories—L. felina originating from an adaptation to the exposed Pacific coast, and L. provocax evolving in freshwater systems. Our findings confirm that L. felina thrives in wave-beaten rocky shores, while L. provocax occupies forested, protected marine, estuarine, and riverine environments, supporting earlier observations from central and southern Chile [9,10,12,25,26,96,97,98,99,100,101,102].
This segregation (Figure 1; Table 1) appears to be primarily structured by physical habitat variables such as wave exposure, slope, and vegetation cover, which explained over 70% of the total variance in the PCA (Figure 5). Specifically, L. felina was strongly associated with steep, sun-exposed rocky walls and sparsely vegetated supralittoral zones, reflecting its specialization for high-energy marine environments. In contrast, L. provocax clustered around sheltered shores with dense low-forest cover and subtidal kelp beds, suggesting a preference for low-energy, structurally complex habitats.
These patterns were statistically supported by multiple analyses. The chi-square test (χ2 = 45.16, p < 0.001) confirmed a significant association between otter species and habitat categories, indicating that the distribution of both species across habitat types is not random. Additionally, Fisher’s exact test yielded similar results (p < 0.001), reinforcing the robustness of this association even under conditions of sparse or unbalanced data. The PCA further highlighted a clear ecological partitioning: L. felina was strongly associated with steep, sun-exposed rocky walls and unvegetated supralittoral zones, while L. provocax was linked to shaded, forested and low-energy shores. The multivariate approaches consistently reveal that L. felina and L. provocax, though regionally sympatric, segregate at finer spatial scales through divergent ecological preferences likely reinforced by behavioral or territorial mechanisms.
From an evolutionary standpoint, the divergence between both species emerged from vicariant processes during the Pleistocene (~883,000 BP) [24,103], followed by differential adaptation. L. felina, adapted to marine conditions much earlier, displays the ability to exploit high-energy environments as well as some incursion into protected areas, such as the Añihue Estuary or Raúl Marín fjord (Table 1), whereas L. provocax, of continental freshwater origin, shows limited marine adaptation and appears unable to colonize oceanic habitats. These patterns support the hypothesis that L. felina may opportunistically use protected areas in the absence of L. provocax, but not the reverse, likely to avoid direct competition for food or habitat [16,63,69,102,104].
These ecological boundaries are also shaped by broad-scale biogeographical factors. As shown in Figure 6, the coastal forest belt critical for L. provocax undergoes a marked latitudinal transition south of 48° S, shifting from tall, continuous evergreen forests to fragmented landscapes dominated by peatlands and stunted vegetation. This vegetational gradient likely imposes structural and trophic constraints that limit the southern distribution of L. provocax, which relies on riparian forest complexity for shelter and prey.
In this context, the highly forested shorelines of northern Patagonia, particularly in Aysén, represent a key bioclimatic refuge for L. provocax. At the same time, these areas retain steep, rocky, and unvegetated margins favorable to L. felina. This juxtaposition of habitats within the same landscape may explain not only the sympatry of both species, but also their contrasting spatial use.
Both otters are top predators, exerting top-down control on invertebrate and fish populations in kelp systems [28,38,48,105,106,107]. Their presence signals ecological functionality, and their decline (particularly of L. provocax), which has experienced local extinctions and contractions from its former range [31,32] warns of broader ecosystem degradation. Given the essential role these predators play, their protection should be a priority in the management of coastal-marine resources. However, herein lies a critical issue: despite their threatened status (L. felina as Vulnerable, L. provocax as Endangered), in Chile, conservation responsibilities are fragmented. Governmental Conservation Agencies like CONAF oversee protected terrestrial areas but lack jurisdiction over the marine coastline, while the National Fisheries Service (SERNAPESCA) regulates aquatic fauna, including otters, as hydrobiological resources. The Ministry of the Environmental of Chile (MMA) has categorized the otters as Vulnerable and Endangered but lacks specific protection and conservation programs. The result is an institutional avoid that leaves many otter populations, especially those outside protected areas without direct protection. There are high hopes that the recently created SBAP (Biodiversity and Protected Areas Service) will be able to promote the protection of specific areas for L. felina and L. provocax.
This is particularly problematic given the expansion of anthropic pressures (mostly fisheries, aquaculture, logging and navigation) on these systems. Of particular concern is brown macroalgal harvesting, because these kelp species are adapted to cold waters, strong waves and turbulence and are part of an ecosystem with higher rates of primary productivity [108], They are considered ecosystems engineers [109] or niche constructors [110] since their body structures supply areas for reproduction, food and refuge for many vertebrate and invertebrates species [28,47,111], including otters as top predators.
The National Fisheries Service (SERNAPESCA) reports annual landings exceeding 35,000 tons of dried Lessonia and Macrocystis in northern Chile (1998–2021), and while harvesting in Aysén is less intensive, it is increasing. Since both otter species rely on the structure and biodiversity of kelp ecosystems, unregulated extraction poses a growing threat, especially in unprotected zones. Considering this, conservation strategies must move beyond isolated protected areas and embrace a bioregional approach.

5. Conclusions

This study reveals that Lontra felina and L. provocax are sympatric species on the marine coast of northern Patagonia, but occupying different habitats mediated primarily by wave exposure intensity and the coastal topography, with cascading effects on vegetation, algal communities, and prey availability.
Wave exposure emerges as the principal ecological determinant, structuring not only the otter presence but also other key factors such as littoral physiognomy, shoreline shading, substrate types, and the structure of the macroalgal belt.
The broader and earlier marine adaptation of L. felina explains its ability to occupy both high-energy coastal fringes and, opportunistically, estuarine sectors. In contrast, L. provocax, of continental origin and more recent marine estuarine colonization, avoids strongly wave-exposed situations and remains confined to protected fjords, river mouths, and inner channels. This asymmetry also prevents competition between species for space and food.
This study documented some L. felina in estuarine areas (Añihue Bay, Ensenada de la Islas, estuary front of Raúl Marín Balmaceda village), tipically L. provocax sites and one L. provocax record at Las Hermanas Islets, a principal L. felina site. In both cases, no co-occurrence or direct interaction between both species was observed. Whether such occurrences represent temporary displacements or indicate a broader tolerance between species remains an open question requiring long-term monitoring.
Given their role as top predators in kelp ecosystems, both otter species act as ecological sentinels. Their persistence depends not only on direct protection but on the conservation of complex and heterogeneous marine-coastal systems. The increasing anthropogenic pressure on these systems, including expanding macroalgae harvesting, underscores the need to address their protection more holistically.
Institutional protection for otters in Chile remains fragmented and insufficient. Neither L. felina nor L. provocax benefit from a clear conservation mandate across their distribution ranges. While one part of the state claims they fall under national park jurisdiction, others argue they are hydrobiological species—resulting in a governance vacuum where key threats are left unaddressed.
Finally, the Raúl Marín Balmaceda Multiple-Use Marine Protected Area (AMP-MU) stands as a valuable model—a site where ecological coexistence, spatial segregation, and habitat diversity can be studied and protected concurrently. Insights from this area offer applicable lessons for marine-coastal planning and underscore the urgency of translating ecological understanding into robust, cross-sectoral conservation strategies.

Author Contributions

All authors greatly contributed to the manuscript. W.S.: coordination, methodology, sampling activity, data analysis, and manuscript writing. C.B.: sampling activity, data analysis, draft preparation. J.A.G.: conceptualization, and manuscript writing and reviewing. M.B.: writing, review and editing. L.S.J.: project administration; A.C.: sampling activities. R.B.: review and editing. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by Fondo de Innovación y Competitividad depending on the Regional Goverment of Aysén Region, Chile (FIC GORE XI Regióm: “Turismo de mamíferos marinos, oportunidades de conservación y desarrollo” during 2020–2023).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Datasets analyzed and generated during the study are included in the article. Additional and complementary information can be requested from the first and second author.

Acknowledgments

The authors wish to thank P. Merino and R. Parra of the AMP Piti-Palena Añihue Foundation of Raúl Marin Balmaceda, for the logistical support and also for the information and photographs on huillín and chungungo from Las Hermanas Islets and Rio Palena Estuary area. In a very special way to J. C. Cubillos from Bahía Santo Domingo, for sharing his experience and deep knowledge of the area aid, collaboration and logistical support provided in accessing the southern sector of the study area (Añihue, Bahía Mala, Los Payos, Isla y Canal Refugio, Islas Guaquel) as well as the contribution of historical information and experience in the sector. To the Regional Government of Aysén for financing the FIC project “Marine Mammal Tourism, Conservation and Development Opportunity”, BIP code 40010337-0, within the framework of which this study was developed, and to the University of Magallanes, which sponsored this initiative. Finally, we are grateful to the captain and crew of the vessel L.M.”Chelo” for their support, goodwill and help in the development of the field campaigns. Finally, to Andreaw Rifo for his help in preparing the maps for the General Directorate of the Los Angeles campus, to the Department of Basic Sciences, and to the School of Education of the Universidad de Concepción for their unconditional support, as well as to the support of the VRID-INTERDISCIPLINARIA project No. 2024001311INT of J. Guzmán.

Conflicts of Interest

Author Raúl Briones was employed by Bioforest S.A. Program Wildlife Conservation. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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Figure 1. Study area and Lontra felina and L. provocax sightings in Northern Patagonia.
Figure 1. Study area and Lontra felina and L. provocax sightings in Northern Patagonia.
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Figure 2. General appearance and characteristics of the rhinarium: (a,b) Lontra felina; (c,d) L. provocax; (e) L. felina in an exposed rocky shore with Durvillea antartica, Chiton granosus and calcareous algae (Islotes Los Payos, accessed on 1 May 2020); (f) L. provocax in a protected and vegetated marine shore (Islas Guaquel, accessed on 2 May 2025). [rhinarium pictures are courtesy of Raúl Briones (b) and Leonardo Fredes (Agriculture Service, Punta Arenas) (d)].
Figure 2. General appearance and characteristics of the rhinarium: (a,b) Lontra felina; (c,d) L. provocax; (e) L. felina in an exposed rocky shore with Durvillea antartica, Chiton granosus and calcareous algae (Islotes Los Payos, accessed on 1 May 2020); (f) L. provocax in a protected and vegetated marine shore (Islas Guaquel, accessed on 2 May 2025). [rhinarium pictures are courtesy of Raúl Briones (b) and Leonardo Fredes (Agriculture Service, Punta Arenas) (d)].
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Figure 3. Attributes 1–3 considered for the habitat description of Lontra felina and L. provocax. Site and date are indicated. (Pictures taken by the first author).
Figure 3. Attributes 1–3 considered for the habitat description of Lontra felina and L. provocax. Site and date are indicated. (Pictures taken by the first author).
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Figure 4. Attributes 4–6 considered for the habitat description of Lontra felina and L. provocax. Site and date are indicated. (Pictures taken by the first author).
Figure 4. Attributes 4–6 considered for the habitat description of Lontra felina and L. provocax. Site and date are indicated. (Pictures taken by the first author).
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Figure 5. Principal Component Analysis (PCA) of habitat attributes associated with Lontra provocax and Lontra felina. The biplot displays the ordination of both species along the first two principal components, which together explain 100% of the total variance. Vectors represent key environmental variables driving segregation between species, while centroids indicate species-specific habitat associations.
Figure 5. Principal Component Analysis (PCA) of habitat attributes associated with Lontra provocax and Lontra felina. The biplot displays the ordination of both species along the first two principal components, which together explain 100% of the total variance. Vectors represent key environmental variables driving segregation between species, while centroids indicate species-specific habitat associations.
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Figure 6. Latitudinal variation in littoral vegetation composition along the Fuego-Patagonian archipelagic gradient, based on forest type proportions per island. Data derived from the Inventario Forestal de AONKEN Consultores [83,84]. Bar plots show the relative abundance (%) of five vegetation categories: stunted forests, normal low forest, normal high forest, general forest, and peatlands. Red stars indicate surveyed locations.
Figure 6. Latitudinal variation in littoral vegetation composition along the Fuego-Patagonian archipelagic gradient, based on forest type proportions per island. Data derived from the Inventario Forestal de AONKEN Consultores [83,84]. Bar plots show the relative abundance (%) of five vegetation categories: stunted forests, normal low forest, normal high forest, general forest, and peatlands. Red stars indicate surveyed locations.
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Table 1. Georeferenced records of otter sightings and detections in northern Patagonia, including both new data (this study) and previously published observations (see also Figure 1 with these points).
Table 1. Georeferenced records of otter sightings and detections in northern Patagonia, including both new data (this study) and previously published observations (see also Figure 1 with these points).
CreditsSiteRecord TypeDateLatitudeLongitudeSpecies
Raimilla (2020) [42]Punta HualaSighting9 November 201943°43′45.2″ S73°02′50.9″ WL. felina
New dataPunta Piti: Los PatosSighting7 November 201943°44′34.0″ S73°00′09.0″ WL. felina
Raimilla (2020) [42]Frente Raúl MarínSighting7 November 201943°46′11.7″ S72°56′37.8″ WL. felina
Parra (2022 Com. Pers) [43]Piti Palena: Ensenada de las IslasVideo26 March 202243°45′53.7″ S72°54′32.9″ WL. provocax
New dataRaúl Marín, Canal GarraoSighting9 February 202243°49′22.6″ S72°57′03.9″ WL. provocax
New dataRio Rodriguez, sector BarraSighting1 November 202143°46′00.9″ S72°49′42.8″ WL. provocax
P. Merino (2022) [43]Las Hermanas islets; north sidePhoto/video4 February 202243°46′08.2″ S73°01′48.7″ WL. felina/L. provocax
New dataLas Hermanas islets; south sidePhoto4 February 202243°46′27.6″ S73°01′47″ WL. provocax
New dataLas Hermanas, islote OestePhoto4 February 202243°46′22.1″ S73°02′53.1″ WL. felina
Raimilla (2020) [42]Islote AlleupaSighting9 November 201943°49′25.9″ S73°01′38.0″ WL. felina
New dataRio Añihue sector bajoSighting5 February 202243°50′10.5″ S72°59′57.5″ WL. provocax
New dataEstero sur, Bahía MalaSighting6 February 202243°55′40.0″ S73°03′31.3″ WL. provocax
Sanino and Meza (2016) [30]Añihue, Islas Velasco 5 PhotoJanuary 2015 to April 201643°52′26.2″ S73°03′05.7″ WL. felina/L. provocax
Sanino and Meza (2016) [30]Añihue, Islas Velasco 6PhotoJanuary 2015 to April 201643°51′28.7″ S73°03′02.1″ WL. felina
Sanino and Meza (2016) [30]Añihue, Islas Velasco 7PhotoJanuary 2015 to April 201643°51′55.7″ S 73°03′13.0″ WL. felina
Sanino and Meza (2016) [30]Añihue, Islas Velasco 8PhotoJanuary 2015 to April 201643°52′13.2″ S73°03′17.1″ WL. felina/L. provocax
Sanino and Meza (2016) [30]Bahía Añihue interior 01PhotoJanuary 2015 to April 201643°52′21.1″ S73°00′56.2″ WL. felina/L. provocax
Sanino and Meza (2016) [30]Bahía Añihue interior 03PhotoJanuary 2015 to April 201643°52′26.3″ S73°00′59.8″ WL. felina
Sanino and Meza (2016) [30]Bahía Añihue interior 10PhotoJanuary 2015 to April 201643°52′28.3″ S73°01′43.5″ WL. felina/L. provocax
New dataIslotes Los PayosSighting5 February 202243°50′48.9″ S73°04′00.3″ WL. felina
New dataIsla Refugio, islotes CrujulSighting29 March 202243°52′48.7″ S 73°08′13.6″ WL. felina
New dataIslas Agnus, Puerto BonitoSighting5 February 202243°53′09.1″ S73°03′39.3″ WL. provocax
New dataIsla Refugio, Punta MelipichúnSighting28 March 202243°57′31.5″ S73°07′25.1″ WL. provocax
New dataIsla Larga, Santo Domingo Sighting6 May 202243°58′03.1″ S73°06′51.2″ WL. provocax
New dataRio RefugioSighting6 February 202243°56′35.1″ S73°04′54.4″ WL. provocax
New dataEstero Santo DomingoSighting6 February 202243°58′42.5″ S73°05′53.6″ WL. provocax
New dataIslas Guaquel 1Photo5 February 202244°01′34.1″ S 73°07′36.1″ WL. provocax
New dataIslas Guaquel 2Photo6 May 202244°01′39.2″ S73°07′20.5″ W L. provocax
Table 2. Habitat attributes associated with Lontra felina and L. provocax sightings in the study area. The “n” column indicates the number of positive sighting sites per species (presence), and “%” represents the proportion of those sites exhibiting each habitat feature).
Table 2. Habitat attributes associated with Lontra felina and L. provocax sightings in the study area. The “n” column indicates the number of positive sighting sites per species (presence), and “%” represents the proportion of those sites exhibiting each habitat feature).
Lontra provocaxLontra felina
AttributesCharactersn%n%
ExpositionExposed 637.50
Semiexposed16.25318.75
Protected1593.75743.75
Grain typeCobles318.75
Boulders212.5
Cliffs1168.7516100.00
Slope≥45°1487.501593.75
<45°212.516.25
VegetationEvergreen forest of Puyuhuapi16100.001062.50
Oceanic evergreen shrub 212.50
Shrub strip of the oceanic coastline 425.00
PhysiognomyNormal high forest211.76
Normal low forest1376.47956.25
Low stunted tres15.88212.50
Grases and herb15.8816.25
Bare devegetated rock 425.00
Shore vegetationVegetated but shady1381.25
Vegetated but sunny212.501062.50
Open16.25637.50
MacroalgaeDurvillaea antartica+Lessonia berteroana/spicata 637.50
Lessonia berteroana/spicata+Macrocystis integrifolia17.69212.50
Macrocystis integtifolia+Lessonia vadosa969.2385.00
Gracilaria+Enteromorpha+Ulva323.08
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Sielfeld, W.; Bunster, C.; Guzmán, J.A.; Buscaglia, M.; Sánchez Jardón, L.; Clark, A.; Briones, R. Habitat Selection of Sympatric Lontra felina and L. provocax in Chilean Patagonia: Toward Sustainable Management. Sustainability 2025, 17, 8290. https://doi.org/10.3390/su17188290

AMA Style

Sielfeld W, Bunster C, Guzmán JA, Buscaglia M, Sánchez Jardón L, Clark A, Briones R. Habitat Selection of Sympatric Lontra felina and L. provocax in Chilean Patagonia: Toward Sustainable Management. Sustainability. 2025; 17(18):8290. https://doi.org/10.3390/su17188290

Chicago/Turabian Style

Sielfeld, Walter, Claudia Bunster, Jonathan A. Guzmán, Marx Buscaglia, Laura Sánchez Jardón, Arturo Clark, and Raúl Briones. 2025. "Habitat Selection of Sympatric Lontra felina and L. provocax in Chilean Patagonia: Toward Sustainable Management" Sustainability 17, no. 18: 8290. https://doi.org/10.3390/su17188290

APA Style

Sielfeld, W., Bunster, C., Guzmán, J. A., Buscaglia, M., Sánchez Jardón, L., Clark, A., & Briones, R. (2025). Habitat Selection of Sympatric Lontra felina and L. provocax in Chilean Patagonia: Toward Sustainable Management. Sustainability, 17(18), 8290. https://doi.org/10.3390/su17188290

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