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Cited by 10Wildlife Ecology and ConservationConservation, Biodiversity, and Resource ManagementSpecies Distribution and Climate Change

A mix of community-based conservation and protected forests is needed for the survival of the Endangered pygmy hippopotamus Choeropsis liberiensis

Open access
Hillers, Annika, Buchanan, Graeme M., Garteh, Jerry C., Tommy, Solomon M., Fofana, Mohamed L., Lindsell, Jeremy A.·2017·Oryx
DOI 10.1017/s003060531600020x
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Abstract

The contribution of protected areas to biodiversity conservation is well attested but many taxa in many regions remain dependent on the unprotected wider landscape. To develop conservation plans for large mammals such as the Endangered pygmy hippopotamus Choeropsis liberiensis of West Africa's Upper Guinea Forests it is critical to understand the importance of unprotected land. Despite being a conservation priority, little is known about the habitat associations of this species, or its distribution across its range. Through a combination of field surveys, species distribution models and community questionnaires we investigated the use of unprotected areas by the pygmy hippopotamus in the Sierra Leone–Liberia border region. We found signs of the species in 128 of 525 1-km 2 cells surveyed. Our analysis suggested that the species is reasonably widespread in this region and is associated with major rivers. It occurred close to, but rarely within, large areas of intact forest, and 80.4% of pygmy hippopotamus signs were recorded outside protected areas. The expansion of the protected area network in this area is unrealistic in Sierra Leone and to some extent in Liberia, mainly because of anthropogenic pressure and the overlap of proposed protected areas with mining and logging concessions. Thus pygmy hippopotamus conservation activities in the region need to include programmes on community lands while maintaining a robust network of protected forests. Community-based conservation of the pygmy hippopotamus may prove valuable for other threatened and endemic species that are not confined to protected areas in this region.

AI snapshot

Written from the paper’s full text.

TL;DR

In the Sierra Leone–Liberia Gola region, pygmy hippopotamus signs were widespread and mostly outside protected areas, associated with rivers and proximity to forest. The authors argue conservation must combine community-based measures on unprotected land with a robust protected forest network.

Key findings

  • Signs were recorded in 128 of 525 surveyed 1-km² cells, at 509 locations; 80.4% (412) of record locations were outside protected-area boundaries, clustered along the Mano, Moro and Moa Rivers.
  • Habitat descriptions were available for 409 locations: farm bush was most frequent (243; 54.41%), followed by forest (99; 24.21%) and rivers/streams/swamps (66; 16.14%); only one record was from a plantation. Footprints, feeding sites and dung were mainly in farm bush, whereas direct sightings and camera-trap photographs were mainly in forest (78.6%).
  • The Maxent model had a mean AUC of 0.985 ± SD 0.006. At the equal sensitivity/specificity threshold (0.206), 6,453 km² were potentially occupied across Sierra Leone and Liberia; at a revised threshold of 0.57, 1,097 km² were identified, correctly predicting 66% of both presences and absences, and suggesting habitat for c. 2,000 female and fewer than c. 600 male pygmy hippopotamus.
  • In 103 communities, 271 respondents were interviewed: 81 communities reported pygmy hippopotamus were present in the past but no longer present, and 17 reported current presence, but signs were found in only eight during follow-up surveys. Over 50% of respondents (148; 54.61%) believed the species was less common than in the past, attributing decline mainly to logging (72), farming (65) and hunting (40).

Methods

  • Field surveys were conducted during July 2010–June 2011 and May 2013–April 2014 along streams and riversides in and around Gola Rainforest National Park and Gola National Forest, searching for footprints, trails, dung, feeding sites, wallows and direct sightings. These were supplemented by camera trapping over 272 km² during 2011–2013, 78 transects during April 2011–July 2012, and ad hoc observations from 2010–2014.
  • Semi-structured community questionnaires were administered in 103 communities during July–November 2010; only respondents able to identify a pygmy hippopotamus from pictures were questioned. Reported encounters were mapped and followed up with field visits.
  • Presence data were used to train maximum entropy models in Maxent 3.3.2, comparing occupied 1-km² cells with 10,000 randomly generated pseudo-absence points, retaining variables explaining at least 1% of model gain, and running 10 cross validations. Population size was extrapolated using home-range estimates of 40–60 ha for females (midpoint 50 ha used) and >150 ha for males.

Limitations

  • The paper states that the species distribution model was based on data from a small area, so caution is needed when extrapolating to the rest of the range; it also failed to identify areas in eastern Liberia where the species is known to occur. The authors note the population estimate was close to the estimated global population, and possible explanations include model overestimation of suitable habitat, omission of hunting/exploitation data, or unrealistically high previous density estimates based largely on translocated individuals.
  • The paper states that data were collected by multiple methods, in different years and by multiple observers, so there may be unquantified errors and biases; survey targeting of streams and swampy areas may also have biased habitat associations. Future surveys should be structured and standardized, and improved density estimates are needed.
  • Evident from the text: most community reports of current presence were unverified, with signs found in only eight of 17 such communities; the questionnaire sample was restricted to respondents who could identify the species; and the paper notes there are no detailed data on the extent of poaching and human–wildlife conflict threats.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1017/s003060531600020x

Cites

44 of 44 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

14 of 38 cited sources checked · 6 supported · 0 flagged · accuracy not yet measured

  • Premisecitation

    Protected areas offer inadequate coverage of the ranges of threatened birds, mammals, amphibians and reptiles at continental and global scales.

    “However, analysis of threatened birds, mammals, amphibians and reptiles at both continental and global scales suggests that protected areas offer inadequate coverage of the ranges of these groups (De Klerk et al., ; Rodrigues et al., ; Beresford et al., a,b; Butchart et al., ).”
    Quote in the paperSubstantial claim2 of 3 sources checked
    • cites De Klerk et al., 2004 source
    • cites Rodrigues et al., 2004 source

      The Results (p. 3) report that 20% of threatened species analysed had no overlap with a protected area, supporting inadequate coverage at the global scale. The Data section (p. 4) shows that the reptile data cover only freshwater turtles and tortoises, and the paper describes a global analysis rather than a continental-scale one. This source therefore does not support the claim's full taxonomic and geographic scope. (LLM, conf=0.87)

      Experimental — accuracy not yet measured
    • cites Butchart et al., 2015 source

      The Results (page not provided) report that fewer than half of assessed mammals and amphibians have enough of their distributions protected to meet species-specific targets. The paper also identifies a global shortfall for mapped threatened species. Our copy does not establish the same finding for reptiles or at continental scales, so it supports only part of the cited claim. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Premisecitation

    In recent decades, forest loss and fragmentation have contributed to a reduction in the occupied range of the pygmy hippopotamus.

    “In recent decades, forest loss and fragmentation have contributed to a reduction in the occupied range of the species (Lewison & Oliver, ; Mallon et al., ; Hodgkinson et al., ).”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites Lewison & Oliver, 2008

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Mallon et al., 2011

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Hodgkinson et al., 2013 source

      The pygmy-hippopotamus passage (indexed as Abstract; page unavailable) says wide-scale deforestation has severely reduced its habitat and that its population has declined. It does not specifically link forest fragmentation to a reduction in occupied range or establish the claimed recent-decades timeframe. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
  • Premisecitation

    Protected area status can mean little in a region where many protected areas are poorly funded and ineffective.

    “Furthermore, riverine habitats can be poorly represented in protected areas (Nel et al., ) but are presumably critical for the pygmy hippopotamus, and in fact protected area status can mean little in a region where many are poorly funded and ineffective (Brugière, ; Henschel et al., ).”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites Brugière, 2012 source

      The Discussion (page unavailable) describes Kankan Faunal Reserve as a “paper park” with no staff or management plan and says its effective contribution to antelope conservation is limited by lack of law enforcement. This supports the point that protected status may offer little practical protection, but the paper does not establish that many protected areas in the region are poorly funded and ineffective. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites Henschel et al., 2014 source
  • Premisecitation

    In many tropical regions, land use conflicts threaten remaining natural habitats outside protected areas and the protected areas themselves.

    “In many tropical regions, such land use conflicts represent a threat not only to remaining natural habitats outside protected areas but even to the protected areas themselves (Forrest et al., ; Laurance et al., ; Tweh et al., ).”
    Quote in the paperSubstantial claim2 of 3 sources checked
    • cites Forrest et al., 2011 source
    • cites Laurance et al., 2012 source
    • cites Tweh et al., 2015 source

      The Discussion (page not provided) reports that extensive natural habitat in Liberia has been assigned to forestry and mining concessions, and that proposed protected areas overlap with future extraction projects. This supports a land-use threat to habitat and proposed protected areas, but the paper does not establish the claim across many tropical regions or show that existing protected areas face the same land-use conflict. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Premisecitation

    Expansion of the protected area network is not always feasible, especially in regions where conservation efforts compete with other land uses such as logging, mineral extraction and agriculture.

    “In some cases the expansion of the protected area network is recommended for more effective protection (Forrest et al., ; Tweh et al., ) but this may not always be feasible (Butchart et al., ), especially in regions where conservation efforts compete with other land uses, such as logging, mineral extraction and agriculture.”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Butchart et al., 2015 source
  • May combine two claims. 27
  • Classified as probably not a substantial claim. 10

  • May combine two claims.

    Premisecitation

    The pygmy hippopotamus is threatened by poaching and human-wildlife conflicts, although detailed data on the extent of these threats are lacking.

    “The pygmy hippopotamus is also threatened by poaching and human-wildlife conflicts (e.g.Greengrass, ; Hillers & Muana, ; Koroma, ; Conway, ; Conway et al., ), although there are no detailed data concerning the extent of these threats.”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites Greengrass, 2011

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Hillers & Muana, 2011

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Conway et al., 2015 source

  • May combine two claims.

    Premisecitation

    The remaining forests harbour a number of threatened large mammals, some of which range beyond the bounds of protected areas.

    “The remaining forests harbour a number of threatened large mammals, some of which are known to range beyond the bounds of protected areas (Merz, ; Junker et al., , ).”
    Quote in the paperSubstantial claim2 of 3 sources checked
    • cites Merz, 1986 source
    • cites Junker et al., 2012 source

      The Introduction describes great apes in remaining forest landscapes and reports chimpanzees throughout Sierra Leone, including a landscape dominated by agricultural fields. It does not establish that those animals range beyond protected-area boundaries, or document that pattern for the other threatened large mammals in the citing sentence. (LLM, conf=0.78)

      Experimental — accuracy not yet measured
    • cites Junker et al., 2015 source

  • May combine two claims.

    Premisecitation

    In Liberia and Sierra Leone only 2 and 5% of the total land area, respectively, is officially protected.

    “In Liberia and Sierra Leone only  and % of the total land area, respectively, is officially protected (Junker et al., ; UNEP, ).”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites Junker et al., 2015 source

      The Introduction states that officially protected areas cover about 2% of Liberia’s total land area. Our copy does not give a corresponding 5% figure for Sierra Leone, so that part of the sentence is not supported by this source (searched: Sierra Leone and 5% protected area). (LLM, conf=0.90)

      Experimental — accuracy not yet measured
    • cites UNEP, 2015

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Multiple-use landscapes and unprotected areas are important for species survival, especially where the existing protected area network does not entirely cover species' ranges and suitable habitats.

    “Multiple-use landscapes and unprotected areas are important for species survival (Gardner et al., ; Perfecto & Vandermeer, ), especially where the existing network of protected areas does not entirely cover species' ranges and suitable habitats; e.g. for some large mammalian carnivores (Forrest et al., ; Swanepoel et al., ) and migratory herbivores (Western et al., ).”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites Gardner et al., 2007 source
    • cites Perfecto & Vandermeer, 2010 source
    • cites Forrest et al., 2011 source

  • May combine two claims.

    Findingown data

    Eighty-one communities reported that pygmy hippopotamus were present in the past but were no longer present, and 17 reported that they were present at the time of the study, but signs of presence were found in only eight of these locations during follow-up surveys.

    “Eighty-one communities reported that pygmy hippopotamus were present in the past but were no longer present, and  reported that pygmy hippopotamus were present at the time of the study but signs of presence were found in only eight of these locations during follow-up surveys (Fig. ).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Community questionnaire respondents who could identify a pygmy hippopotamus from pictures accurately report the species' presence, absence and past occurrence in their locality.

  • May combine two claims.

    Findingown data

    By far the largest area of potentially suitable habitat for the pygmy hippopotamus is around the Gola region, where much of the suitable habitat falls outside Gola Rainforest National Park and Gola National Forest.

    “By far the largest area of potentially suitable habitat is around the Gola region (Fig. ), where much of the suitable habitat falls outside Gola Rainforest National Park and Gola National Forest (Fig. b).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    A comparison of likelihood of occupancy at apparent absences with values at confirmed presences produced an ROC of 0.71, with a revised equal sensitivity and specificity threshold of 0.57.

    “A comparison of likelihood of occupancy at these apparent absences with the values at confirmed presences (rather than pseudo absences from the model building process) produced an ROC (receiver operating characteristic) to ., with a revised equal sensitivity and specificity threshold of ..”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The majority of reported extinctions were along the more heavily settled northern boundary of Gola Rainforest National Park, but field surveys indicated that the species persists in part of this area.

    “The majority of the reported extinctions were along the more heavily settled northern boundary of Gola Rainforest National Park.However, field surveys indicated that the species persists in part of this area (Fig. ).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Community questionnaire respondents who could identify a pygmy hippopotamus from pictures accurately report the species' presence, absence and past occurrence in their locality.

  • May combine two claims.

    Findingreasoning

    At the revised threshold, 66% of both presences and absences were correctly predicted, and 1,097 km2 across Sierra Leone and Liberia were identified as potentially occupied by the pygmy hippopotamus.

    “At this threshold % of both presences and absences were correctly predicted, and , km  across Sierra Leone and Liberia were identified as potentially occupied by the pygmy hippopotamus.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Footprints, feeding sites and dung were mainly recorded in farm bush areas, whereas direct sightings and camera-trap photographs were mainly recorded in forest.

    “Footprints (.%), feeding sites (.%) and dung (.%) were mainly recorded in farm bush areas (Fig. ), whereas direct sightings and camera-trap photographs were mainly recorded in the forest (.%).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pygmy hippopotamus signs such as footprints, trails, dung, feeding sites, wallows and direct sightings reliably indicate the presence of the species at a location.

  • May combine two claims.

    Findingown data

    Modelled pygmy hippopotamus distribution based on 128 occupied 1-km2 cells was most strongly associated with climatic variables and distance to rivers and closed forest, with areas closer to rivers and forest more likely to be occupied.

    “Modelled pygmy hippopotamus distribution, based on the  occupied -km  cells, was most strongly associated with climatic variables and distance to rivers and closed forest, with response curves indicating that areas closer to rivers and forest were more likely to be occupied (Fig. ).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pygmy hippopotamus signs such as footprints, trails, dung, feeding sites, wallows and direct sightings reliably indicate the presence of the species at a location.

  • May combine two claims.

    Findingown data

    The model correctly identified 121 of the 128 locations with sightings but incorrectly predicted 302 of 397 apparently unoccupied squares to be occupied.

    “The model correctly identified  of the  locations with sightings but it incorrectly predicted  of the  apparently unoccupied squares (locations surveyed but at which no signs of pygmy hippopotamus were recorded) to be occupied.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Findingcitation

    The pygmy hippopotamus prefers mainly unprotected farm bush areas.

    “The pygmy hippopotamus' preference for mainly unprotected farm bush areas may also be linked to the presence of the herbaceaous plant Triumfetta cordifolia”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Many of the potentially suitable habitat patches are small and isolated, perhaps rendering them unsuitable.

    “Many of these patches are small and isolated (Fig. ), perhaps rendering them unsuitable.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    The data used in this analysis were collected by multiple methods, in different years and by multiple observers.

    “The data used in this analysis were collected by multiple methods, in different years and by multiple observers.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The pygmy hippopotamus is the largest species entirely endemic to the Upper Guinean Forest and is therefore amongst the most vulnerable to habitat loss and fragmentation in the region.

    “Of these, the pygmy hippopotamus Choeropsis liberiensis, categorized as Endangered on the IUCN Red List (Ransom et al., ), is the largest species that is entirely endemic to the Upper Guinean Forest and is therefore amongst the most vulnerable to habitat loss and fragmentation in the region.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Ransom et al., 2015

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisenone given

    Proposed protected areas largely overlap with logging and mining concessions, which jeopardizes further declarations of protected areas.

    “However, proposed protected areas largely overlap with logging and mining concessions, which jeopardizes further declarations of protected areas.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Some of the apparent selection for streams and swampy areas, especially in the analysis of field surveys, might have been because of the targeting of these areas for surveys.

    “Some of the apparent selection for streams and swampy areas, especially in the analysis of field surveys, might have been because of the targeting of these areas for surveys.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Protected area coverage in the region is inadequate and falls below the Convention on Biological Diversity Aichi Target of at least 17%.

    “These figures suggest that the protected area coverage in the region is inadequate, and falls below the Convention on Biological Diversity Aichi Target of at least % (CBD, ).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites CBD, 2010

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationnone given

    Areas mapped as potentially suitable may be covered by habitat broadly suitable for the species, yet the species may be absent for reasons such as hunting pressure or fragmentation.

    “Areas mapped as potentially suitable (such as around the coast of Sierra Leone) may be covered by habitat that is broadly suitable for the species, yet it may be absent for reasons such as hunting pressure or fragmentation.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Expansion of the protected area network in the Gola region is unrealistic in Sierra Leone and to some extent in Liberia, mainly because of anthropogenic pressure and overlap of proposed protected areas with mining and logging concessions.

    “The expansion of the protected area network in this area is unrealistic in Sierra Leone and to some extent in Liberia, mainly because of anthropogenic pressure and the overlap of proposed protected areas with mining and logging concessions.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    The model only examined habitat and did not include data on potential exploitation, such as hunting for bushmeat.

    “Secondly, our model only examined habitat and did not include data on potential exploitation, such as hunting for bushmeat.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationnone given

    Community-based conservation of the pygmy hippopotamus may prove valuable for other threatened and endemic species that are not confined to protected areas in this region.

    “Community-based conservation of the pygmy hippopotamus may prove valuable for other threatened and endemic species that are not confined to protected areas in this region.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductreasoning

    These biases might have continued to influence the species distribution models, but comparison of occupied areas with a large number of pseudo absences should reduce the impact of this potential bias.

    “These biases might have continued to have an influence on the species distribution models but comparison of occupied areas with such a large number of pseudo absences should reduce the impact of this potential bias.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    In the Gola region, the pygmy hippopotamus is generally found in association with streams or swampy areas, mostly outside protected areas, and in close proximity to forests including protected forests.

    “Field surveys, species distribution models, and community questionnaires all indicate that in the Gola region the pygmy hippopotamus is generally found in association with streams or swampy areas, mostly outside protected areas, and in close proximity to forests (including protected forests).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pygmy hippopotamus signs such as footprints, trails, dung, feeding sites, wallows and direct sightings reliably indicate the presence of the species at a location.
    • Rests on an assumption: Community questionnaire respondents who could identify a pygmy hippopotamus from pictures accurately report the species' presence, absence and past occurrence in their locality.

  • May combine two claims.

    Interpretationown data

    The outputs of the distribution model are supported by field observations and suggest that the most suitable habitat for the pygmy hippopotamus is in the unprotected, community-owned landscape.

    “The outputs of the distribution model are supported by the field observations and suggest that the most suitable habitat is in the unprotected, community-owned landscape.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Although there might be suitable habitat to support a high number of individuals, the actual numbers may be lower as a result of hunting.

    “Thus, although there might be suitable habitat to support a high number of individuals, the actual numbers may be lower as a result of hunting.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    There may be unquantified errors and biases in the data.

    “Consequently there may be unquantified errors and biases in our data.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    The model's overprediction of occupied squares may arise where suitable habitat is unoccupied or where pygmy hippopotamus were undetected in occupied sites, or it may indicate high sensitivity but low specificity.

    “This can arise where suitable habitat is unoccupied or where pygmy hippopotamus were undetected in occupied sites, or it may indicate that the model had high sensitivity but low specificity (i.e. it overpredicted potential distribution).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    Closed forest was of equal or perhaps greater importance than proximity to streams and rivers according to the models, but it was not the most frequented habitat according to field surveys.

    “Closed forest, although of equal or perhaps greater importance than proximity to streams and rivers according to the models, was not the most frequented habitat according to field surveys.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Riverine habitats can be poorly represented in protected areas but are presumably critical for the pygmy hippopotamus.

    “Furthermore, riverine habitats can be poorly represented in protected areas (Nel et al., ) but are presumably critical for the pygmy hippopotamus, and in fact protected area status can mean little in a region where many are poorly funded and ineffective (Brugière, ; Henschel et al., ).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Nel et al., 2007 source

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationreasoning

    Larger streams and lowland areas are more prevalent in Gola National Forest than Gola Rainforest National Park, which may explain the greater number of pygmy hippopotamus detections in the former.

    “Larger streams and lowland areas are more prevalent in Gola National Forest than Gola Rainforest National Park, which may explain the greater number of detections in the former, despite”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationnone given

    Community-level approaches may also be more successful in addressing threats unrelated to habitat, such as hunting.

    “Such community-level approaches may also be more successful in addressing threats unrelated to habitat, such as hunting.”
    Quote in the paperNot a substantial claim
33 of 33

  • The paper relies on this without support.

    Pygmy hippopotamus signs such as footprints, trails, dung, feeding sites, wallows and direct sightings reliably indicate the presence of the species at a location.

    “searching carefully for signs of the species (footprints, trails, dung, feeding sites, wallows, direct sightings), especially where the substrate might preserve footprints or conditions were suitable for a wallow or foraging.”
    “Pygmy hippopotamus and their signs were recorded at  locations in  of these cells (Fig. ).”

  • The paper relies on this without support.

    Community questionnaire respondents who could identify a pygmy hippopotamus from pictures accurately report the species' presence, absence and past occurrence in their locality.

    “Only respondents who could identify a pygmy hippopotamus from a set of pictures of large mammals were questioned.”
    “Responses about encounters with the pygmy hippopotamus were mapped and reports of the species' presence were investigated by field visits.”

  • The paper relies on this without support.

    No follow-up research has investigated the impact and success of environmental education and outreach programmes for the pygmy hippopotamus.

    “However, no follow-up research has investigated the impact and success of these programmes so far”

  • The paper relies on this without support.

    The pygmy hippopotamus is known to occur in eastern Liberia (e.g., Sapo National Park, Grebo National Forest).

    “where the pygmy hippopotamus is known to occur.”
4 of 4

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Most geospatial variables were selected because they have been proven important to the pygmy hippo in other modelling studies, except distance to camps which represents major sources of noise and human activity.

    “Most of these were selected because they have been proven important to the pygmy hippo in other modelling studies (Bogui et al., 2016; Freeman et al., 2019; Hillers et al., 2017), except for 'distance to camps ' , which was included because it represents major sources of noise and human activity in our study area.”

    From Fine-scale habitat requirements of the pygmy hippopotamus (Choeropsis liberiensis): Implications for rainforest conservation in West Africa (2026) · cites this paper as Hillers et al., 2017

  • Multiple years of extensive ecological surveys in the transboundary Lofa-Gola-Mano forest complex yielded relatively few pygmy hippo signs within protected areas compared to community-managed areas and former agricultural sites.

    “Additionally, multiple years of extensive ecological surveys in the transboundary Lofa-Gola-Mano forest complex of Liberia and Sierra Leone yielded relatively few pygmy hippo signs within protected areas compared to the number of signs recorded in community-managed areas and former agricultural sites (Garteh, 2013; Hillers et al., 2017; Klop et al., 2008).”

    From Fine-scale habitat requirements of the pygmy hippopotamus (Choeropsis liberiensis): Implications for rainforest conservation in West Africa (2026) · cites this paper as Hillers et al., 2017

Cites

Flagged first, then by citations

2 of the 46 references couldn’t be matched to a known paper.

Research works printed but not linked: 10

  1. Steck, 2015, International Studbook for the Pygmy Hippopotamus 2014
  2. Brown, 2011, Sustainable Natural Resource Management in Namibia: Successful Community-Based Wildlife Conservation
  3. Koroma, P.Y. (2012) Analysis of the distribution of large mammals around the Gola Rainforest National Park (Malema Chiefdom) based on a camera trap study, with a focus on key bushmeat species. BSc thesis. Eastern Polytechnic, Kenema, Sierra Leone.
  4. Klop, 2008, Biodiversity of Gola Forest, Sierra Leone
  5. Hillers, 2011, Pygmy Hippopotamus Conservation Project Within the “Across the River—A Transboundary Peace Park for Sierra Leone and Liberia” Project (ARTP)
  6. Lahai, K. (2013) The distribution of key species in the Gola Forests – a comparison between the Gola Rainforest National Park in Sierra Leone and the Gola National Forest in Liberia. A case study in Gola Central (Nomo, Gaura, Malema and Tunkia Chiefdoms). BSc thesis. Eastern Polytechnic, Kenema, Sierra Leone.
  7. 2000, Upper Guinean Forest Ecosystem of Guinean Forests of West Africa Biodiversity Hotspot
  8. 2014, Human Development Report 2014. Sustaining Human Progress: Reducing Vulnerabilities and Building Resilience
  9. Hillers, 2013, Final Report on the Activities of the Research Unit, Across the River—A Transboundary Peace Park for Sierra Leone and Liberia, 2010 to 2013
  10. Greengrass, 2011, Exploring the Dynamics of Bushmeat Hunting and Trade in Sapo National Park

Cited by

Sorted by citations

Related

Authors
Hillers, A., Buchanan, G. M., Garteh, J. C., Tommy, S. M., Fofana, M. L., & Lindsell, J. A.
Affiliations
Royal Society for the Protection of Birds (GB)
Corresponding author
Hillers, Annika
ORCID
Venue
Oryx
Publisher
Cambridge University Press (CUP)
Published
2016-06-07
Volume
51
Issue
2
Pages
230-239
ISSN
  • 0030-6053 (ISSN-L)
  • 1365-3008
DOI
10.1017/s003060531600020x
OpenAlex
W2410937811
Cited by
10
References
46
Citations by year
2026: 2 · 2024: 2 · 2023: 1 · 2021: 2 · 2020: 1 · 2019: 2
FWCI
0.57
Type
journal article
Language
en
Open access
Licence
www.cambridge.org/core/terms (unspecified)
Locations
Oryx (publishedVersion)
Funders
  • Vogelbescherming Nederland
  • Royal Society
  • European Commission
Topics
  • Physical Sciences › Environmental Science › Ecology › Wildlife Ecology and Conservation
  • Physical Sciences › Environmental Science › Global and Planetary Change › Conservation, Biodiversity, and Resource Management
  • Physical Sciences › Environmental Science › Ecological Modeling › Species Distribution and Climate Change
Keywords
pygmy hippopotamus, Choeropsis liberiensis, community-based conservation, protected areas, habitat use, species distribution, Upper Guinea Forest, riverine habitat, anthropogenic pressure, endangered species conservation

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-27.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-27.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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