Coendou vestitus: Assessing the conservation status of the Brown Hairy Dwarf Porcupine in Colombia.

The Brown Hairy Dwarf Porcupine, Coendou vestitus, is one of the rarest of the seven species of Porcupines (genus Coendou) that occur in Colombia. It is a small species (head–body length 330–370 mm), characterized by having three types of fur: long dorsal fur, bicolored defensive fur, and bristles. Since its description more than a century ago, it has been recorded from only six localities. This species is considered endemic to both sides of the Eastern Cordillera in the Colombian Andes, which is a complex ecosystem with topographical and biological diversity and high levels of endemism. Andean ecosystems are a global conservation priority as only 25% of their original extent remains.

Although Coendou vestitus is considered rare this condition has not been evaluated, and it has been suggested based only on the absence of data and the paucity of voucher specimens. Information on the ecology, genetics, natural history and conservation status of the species is also scarce, and in the case of the latter, contradictory. This Porcupine is categorized as Data Deficient on the International Union for the Conservation of Nature's Red List of Threatened Species, with the assessment considering the presence of the species from only two localities, although in the same assessment three localities were mentioned. Nationally, the species has been categorised as Vulnerable based on its reduced geographical range as a result of habitat loss and fragmentation. Currently, it is the only Porcupine species categorised as threatened in Colombia. 

In a paper published in the journal Orynx on 17 November 2020, María Torres-Martínez of the Programa de Pós-graduação em Ecologia e Conservação and Laboratório de Biodiversidade, Conservação e Ecologia de Animais Silvestres at the Universidade Federal do Paraná, Héctor Ramírez-Chaves of the Departamento de Ciencias Biológicas and Museo de Historia Natural at the Universidad de Caldas, Elkin Noguera-Urbano of the Instituto de Investigación de Recursos Biológicos, Alexander von Humboldt, and Fernando Passos, also of the  Programa de Pós-graduação em Ecologia e Conservação and Laboratório de Biodiversidade, Conservação e Ecologia de Animais Silvestres at the Universidade Federal do Paraná, evaluate the level of rarity of the Brown Hairy Dwarf Porcupine and reassess its conservation status, based on available literature, specimens in natural history museums and collections, and data from recent records.

To evaluate the rarity of the species Torres-Martínez et al. followed the criteria of Jinpeng Yu & Stephen Dobson, based on four characteristics: (1) local population density, (2) range, (3) the number of habitat types in which the species occurs and (4) body size. In addition, Torres-Martínez et al. suggest factors that may have determined the rarity category of this species. As the species population density has not been assessed, Torres-Martínez et al. documented the number of records per year since the species description. They consider the population density to be low if the number of records evaluated is less than one for each ten-year interval (there are about 10 000 records of Mammals in databases for  Cundinamarca, the department in which Coendou vestitus has been historically recorded). Torres-Martínez et al. also estimated the species range and related this to the rarity level using the extent of occurrence and area of occupancy. They calculated the extent of occurrence using the minimum convex polygon (linking the known points of occurrence for the species), and the area of occupancy by summing the area of grid squares in which the species is known (using grid squares of 2 km² as recommended by the International Union for the Conservation of Nature) in GeoCAT. For this Torres-Martínez et al. used data from six confirmed localities. Three of these are voucher specimens housed at Colombian collections and the other three are photographic records. The photographs showed characters used to differentiate Coendou vestitus from other species in this genus: dorsal pelage with long blackish fur that partially or completely conceals defensive quills, and bicoloured bristle-quills. Torres-Martínez et al. excluded one voucher specimen, ICN 3505, from their analyses because the specimen was transported from another locality in the western part of the Eastern Cordillera; the location on the label of the specimen is in a market area.

Torres-Martínez et al. also considered the number of habitats occupied by the species. For this, they overlaid the extent of occurrence on the ecoregions of Colombia, following the classification of terrestrial ecoregions. Torres-Martínez et al. evaluated body size based on information from the labels of the reviewed voucher specimens and from the literature, and compared this trait with other species of Coendou.

To reassess the species conservation status, Torres-Martínez et al. used information on the level of rarity, extent of occurrence and area of occupancy. They included the level of rarity and the ecoregions the species inhabits to infer the conservation status of the species because of the absence of information on other factors that can influence the area of occupancy, such as biotic interactions (predation, competition) and landscape (connectivity and shelter). Torres-Martínez et al. also examined whether the extent of occurrence or area of occupancy of Coendou vestitus overlaps with protected areas, by using the protected areas layer for Colombia, and evaluated the per cent of forest area that remained unchanged during 2016-2017 within the polygon of the species range. To evaluate overlap of the area of occupancy and extent of occurrence with protected areas, Torres-Martínez et al. estimated the extent (km²) of protected areas inside the extent of occurrence polygon using as a limit the elevational range of the species, and determined the number of confirmed localities inside protected areas.

Torres-Martínez et al.'s findings indicate that Coendou vestitus matches the criteria of an extremely rare species

From the description of Coendou vestitus to the present, Torres-Martínez et al. found only 12 voucher specimens and photographs of three living specimens. Three records had no precise locality information. The records date from the species description in 1889 to photographic records from Cundinamarca in 2018. The scarcity of records suggests a low population density, considering that several biological expeditions have visited the area in which the species occurs (Cundinamarca is the Department in which Bogotá, the capital of Colombia and home of the main Colombian academic institutions, is located).

 

Photographic record (June 2018) of Coendou vestitus from Pedro Palo, Tena, Colombia. Sergio Chaparro in Torres-Martínez et al. (2020).

It has been suggested that the elevational range of Coendou vestitus is 1300–2600 m, 250-2000 m, and 600-1440 m. However, based on the information from confirmed localities, and discarding a dubious record from Villavicencio, the elevational range appears to be from 1250 m (Cundinamarca, Quipile) to 2600 m (Cundinamarca, Chicaque). The estimated area of the species range is based on only six confirmed localities, with an estimated extent of occurrence of 3320 km² and an area of occupancy of 24 km².

 

Extent of occurrence of Coendou vestitus, with (a) protected areas within the extent of occurrence, indicating the two records in protected areas, and (b) forest coverage in 2016-2017. Torres-Martínez et al. (2020).

Overlaying the extent of occurrence on the terrestrial ecoregions map indicated that the species only occurs in tropical moist broadleaf forest. This ecoregion corresponds to the highly threatened sub-Andean and Andean forests.

The adult body size of Coendou vestitus (total length of head and body 330-370 mm) is within the range observed for small Coendou species (Coendou insidiosus 310-350 mm; Coendou nycthemera 290-380 mm; Coendou pruinosus 320-380 mm; Coendou rufescens 340-410 mm; Coendou melanurus 330-435 mm; Coendou quichua 330-440 mm; Coendou speratus 330-440 mm; Coendou spinosus 285-470 mm; Coendou bicolor 450-500 mm; Coendou prehensilis 430-500 mm), being the third smallest species of the genus after Coendou ichillus (260-290 mm) and Coendou roosmalenorum (290 mm). Coendou vestitus has, however, a considerably shorter tail than the latter species.

Torres-Martínez et al. found only two localities (of the six confirmed) within conservation areas (33.3% of the occurrences), although the extent of occurrence polygon intersected with 35 protected areas, managed by two institutions (Corporación Autónoma Regional and Parques Naturales Nacionales de Colombia). Specifically, these 35 areas include one Soil Conservation District, five Regional Protected Forest Reserves, eight Regional Integrated Management Districts, and 21 Natural Civil Society Reserves. The portions of the protected areas within the extent of occurrence polygon have a total area of 1025 km², with 1298 km² of the extent of occurrence not lying within protected areas. When overlapping the forest coverage with the extent of occurrence polygon, the forest coverage during 2016-2017 was 219 km² (6.6%). Considering the species’ range and its rarity, Torres-Martínez .et al recommend that Coendou vestitus is recategorized from Data Deficient to Endangered based on the following criteria: an of less than 5000 km², and continuing decline inferred in extent and/or quality of habitat, number of locations or subpopulations, and the number of mature individuals, and similarly with an area of occupancy of under 500 km²; the population size is estimated to number less than 2500 mature individuals with a continuing decline, observed, projected, or inferred, and, continuing decline, observed, projected or inferred, in numbers of mature individuals, and extreme fluctuations in number of mature individuals.

Torres-Martínez et al.'s recommendation to categorise Coendou vestitus as Endangered follows International Union for the Conservation of Nature recommendations to assess poorly known taxa based on information on inferred habitat loss and restricted distribution, to avoid assigning a Data Deficient category. The current International Union for the Conservation of Nature information is incomplete (with area of occupancy and extent of occurrence unknown) because it includes data for only from two localities.  The periodic re-evaluation of a species’ Red List status is an important tool for the planning, monitoring and management of biodiversity conservation.

Besides being an endemic and rare species, Torres-Martínez et al.'s findings confirm that Coendou vestitus is restricted to an ecosystem in which habitat is being lost and there are continuing threats from anthropogenic transformation. The Eastern Cordillera comprises 40% of Andean ecosystems, but only 27% of its original vegetation cover remains. Although this region is characterised by high species richness and endemism it is one of the least known and least protected ecosystems. Habitat loss affects the persistence of small Mammals, which play important ecological roles, for example as seed dispersers of pioneer species, and in trophic and predator–prey relationships.

Although Coendou vestitus has previously been considered a rare species because of the scarcity of records, there are other reasons for it to be considered rare. Although other Porcupines in Colombia are known from fewer specimens (e.g. Coendou ichillus), they are not endemic to the country, having a wider distribution. Torres-Martínez et al.'s confirmation of rarity is based on a combination of apparent low local population density, a small range, occurrence in only one habitat type, and small body size.

In general, small-sized species of Coendou (e.g. Coendou. ichillus, Coendou roosmalenorum and Coendou vestitus) have more restricted distributions in the northern part of South America compared to the larger species that have only one type of quills in adulthood (e.g. Coendou prehensilis and Coendou bicolor). The rarity of Coendouvestitus is perhaps associated with homoplastic functional traits such as the presence of three types of hairs in adulthood (i.e. with less protection against predators than species with a body fully-covered by quills) and small body size. Several species of African small Mammals have been categorized as rare or Vulnerable because their size could influence predator–prey relationships. In this context, additional morphological characters may confer an adaptive advantage to large Coendou species: a body mostly covered by quills in adulthood provides a possible advantage against predators, the swollen nasofrontal sinuses protect the brain, and a larger tail facilitates arboreal locomotion, as observed in Coendoubicolor and Coendouprehensilis. The morphological and/or evolutionary reasons for the restricted range of small-sized Coendou are, however, as yet unclear, and require further research.

Although 106 genera, 333 species and 61 subspecies of Rodents are considered threatened and have high endemism, a relatively lower percentage of Rodents are categorised as threatened compared to other Mammalian groups. No Coendou species are as yet categorized as threatened, six are categorised as Data Deficient, including Coendou vestitus, and eight as Least Concern.

The only locations of Coendouvestitus within protected areas are in the 2.44 km² Nature Reserve Parque Natural Chicaque and the 0.45 km² Natural Civil Society Reserve Tenasuca de Pedro Palo, which together correspond to only 0.08% of the species’ range. In addition to the small extent of occurrence, the area of the 35 protected areas within the extent of occurrence is small (a mean of 29 km² per protected area). The area surrounding the extent of occurrence is severely affected by extensive commercial plantations and urban settlements, with only about 50% of the ecoregion unaffected. This limits connectivity, which is important for the persistence of a species. Maintenance, extension or connection of protected areas, connecting the relict habitats, could help to protect Coendou vestitus.

Conservation strategies and financial resources need  be established for threatened and endemic species and for species with restricted distributions. However, for Mammals most monitoring and conservation efforts are directed at large or charismatic species. Less attention has been directed at Rodents, even though the group has a high extinction rate. Prioritising the conservation of Coendou vestitus has the potential to contribute to the protection of the ecosystems in which it occurs and of co-occurring species. Torres-Martínez .et al recommend that national agencies prioritise this Porcupine species, together with other species in urgent need of monitoring.

Porcupines remain a poorly known group, both at national and Neotropical levels. Knowledge of the ecology of Coendou vestitus is mostly based on inference from other Porcupine species. Torres-Martínez et al.'s compilation of information on  Coendou vestitus highlights the need for further fieldwork and data collection. Nevertheless, threats to Porcupines are evident, in particular loss of habitat, illegal trade, road-kills, and hunting for consumption. In Colombia, illegal captivity has also been documented (on a voucher specimen label) as a threat to the species. Torres-Martínez et al.'s compilation of data and our findings form the basis for further research and for the establishment of conservation strategies and future evaluations of the distribution and conservation status of Coendou vestitus.

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