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Cited by 3Conservation, Biodiversity, and Resource ManagementLand Use and Ecosystem ServicesWildlife Ecology and Conservation

Forest loss during 2000–2019 in pygmy hippopotamus (Choeropsis liberiensis) habitats was driven by shifting agriculture

Open access
Erazo-Mera, Estefania, Younes, Nicolás, Horwood, Paul F, Paris, Damien, Paris, Monique, Murray, Nicholas·2024·Environmental Conservation
DOI 10.1017/s0376892923000310
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Abstract

Summary: The Upper Guinea Forest (UGF; West Africa), a global biodiversity hotspot, has lost more than 90% of its original area since 1900, threatening endemic species such as the endangered pygmy hippopotamus (Choeropsis liberiensis). However, little is known about the proximate causes of this deforestation. We classified Sentinel-2 data using the random forest algorithm to differentiate between three main human processes (shifting agriculture, intensive agriculture or urban expansion) driving deforestation between 2000 and 2019 across the pygmy hippopotamus distribution area. Out of c. 89 600 km 2 in the year 2000, 15 900 km 2 (17%) of forest were lost, primarily to shifting agriculture (14 900 km 2). Côte d’Ivoire and Liberia accounted for 14 900 km 2 (94%) of the net area of forest lost, c. 15 times greater than deforestation in Sierra Leone and Guinea combined (953 km 2). Forest loss inside protected areas is pervasive, and it is essential to prioritize conservation efforts in areas where deforestation is still low (e.g., Taï, Sapo and Gola Rainforest national parks). We suggest that the preservation of the UGF will face challenges associated with people’s demand for food and income. Continued landscape-scale planning and action to reduce deforestation are urgently needed to limit the impact of shifting agriculture on pygmy hippopotamus habitat.

AI snapshot

Written from the paper’s full text.

TL;DR

Using Sentinel-2 imagery and a random forest classifier, the study maps 2000–2019 forest loss across the pygmy hippopotamus range in the Upper Guinea Forest and finds that c. 15,900 km² was lost, overwhelmingly to shifting agriculture. Protected areas also lost forest, but Taï, Sapo and Gola Rainforest national parks retained most intact habitat.

Key findings

  • Of c. 89,600 km² of forest with ≥50% canopy cover in 2000, 15,900 km² (17%) was lost by 2019; shifting agriculture accounted for 14,868 km² (93.4%), urban expansion 889 km² (5.6%) and intensive agriculture 144 km² (1.0%).
  • Côte d’Ivoire and Liberia accounted for 14,948 km² (94%) of net forest loss, c. 15 times greater than Sierra Leone and Guinea combined (953 km²); normalized loss was highest in Sierra Leone (15.9%), followed by Côte d’Ivoire (12.3%), Liberia (9.6%) and Guinea (8.0%).
  • Inside protected areas, 4,835 km² (15.8%) of forest was lost; shifting agriculture drove 4,568 km² (93.5%), urban expansion 254 km² (5.6%) and intensive agriculture 13 km² (1.0%). Liberia had the highest normalized protected-area loss (33.7%), followed by Côte d’Ivoire (15.5%).
  • Taï, Gola Rainforest and Sapo national parks account for 25% of protected habitat in the pygmy hippopotamus distribution but only 2% of deforestation inside protected areas; forest loss there was negligible and unrelated to the assessed drivers.

Methods

  • The study area was the known pygmy hippopotamus distribution (140,221 km² across Guinea, Sierra Leone, Liberia and Côte d’Ivoire). Forest loss was identified using the Hansen Global Forest Change dataset v1.7 (2000–2019), limited to areas with ≥50% canopy cover in 2000 (89,614 km²). Sentinel-2 level 2A 10-m imagery from 2019 (n = 3,108) was cloud-masked, and eight spectral indices plus composite metrics yielded 182 covariate layers.
  • A random forest model with 300 trees classified forest-loss pixels into three driver categories: shifting agriculture, intensive agriculture and urban expansion. Training used 1,150 points and independent accuracy assessment used 450 points; a majority filter removed isolated pixels. Overall accuracy was 87%, with class accuracies of 96% for urban expansion, 86% for intensive agriculture and 81% for shifting agriculture.
  • Protected-area analysis used 87 declared protected areas partially or totally inside the pygmy hippopotamus range, covering 30,669 km² (22% of the study area), from UNEP-WCMC and IUCN. Driver areas were computed by country inside and outside protected areas.

Limitations

  • Stated: persistent cloud cover and spectral similarity between forests and plantations often caused driver misclassification; the low number of cloud-free images and similar spectral signatures led the authors to combine driver classes into three broad categories. Training data were not collected where high-resolution imagery was unavailable or clouds were prevalent, such as southern Liberia and western Côte d’Ivoire.
  • Stated: the classification model could be improved by including more drivers (e.g., individual crops, fire). The authors note that high cloud prevalence and spectral similarity remain limitations, and that newer sensors could help but may be costly and involve trade-offs such as reduced spectral resolution.
  • Evident from the text: livestock grazing areas were merged into the “shifting agriculture” class because their spectral signatures and image interpretation cues were similar, so that class likely includes grazing as well as smallholder cultivation.

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

Integrity signals

Registry

Crossref · 10.1017/s0376892923000310

Cites

49 of 49 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

8 of 42 cited sources checked · 3 supported · 0 flagged · accuracy not yet measured

  • Interpretationcitation

    Rapid population growth will probably involve further deforestation, even in protected areas.

    “Although 'Urban expansion' was not the most important driver of forest loss in our study area, rapid population growth will probably involve further deforestation, even in protected areas (Fig. 4).”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Seto et al. 2012 source

      The Abstract forecasts substantial urban expansion and habitat loss, and the Discussion describes land clearing and forest degradation associated with that expansion. The paper does not establish that rapid population growth will cause deforestation in protected areas; its Discussion also notes uncertainty about population growth as a driver of urban expansion. (LLM, conf=0.82)

      Experimental — accuracy not yet measured
  • Premisecitation

    Some of the pygmy hippopotamus decline was related to hunting for bushmeat and other purposes during times of internal conflict in the region.

    “Some of this decline was related to hunting for bushmeat and other purposes during times of internal conflict in the region (Conway 2013, Conway et al. 2015).”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites Conway 2013

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

    • cites Conway et al. 2015 source

      The Introduction identifies poaching as a factor in pygmy hippo decline, and “Pygmy hippo ecology and human-hippo interactions” reports hunting and consumption of pygmy hippo meat. The paper mentions the civil war in “Local perceptions of the benefits of pygmy hippo conservation,” but does not link hunting or the decline to periods of internal conflict. Page numbers are unavailable in our copy. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Premisecitation

    Pygmy hippopotami are known to inhabit the protected areas within their range.

    “There are 87 protected areas covering 30 669 km 2 that are partially or totally located inside the pygmy hippopotamus's range (UNEP-WCMC & IUCN 2021), and pygmy hippopotami are known to inhabit them (Roth et al. 2004, Collen et al. 2011, Garteh 2013, Conway et al. 2015, Bogui et al. 2016, Hillers et al. 2017, Ouattara et al. 2018).”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites Roth et al. 2004 source
    • cites Collen et al. 2011 source
    • cites Garteh 2013

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

  • Interpretationcitation

    Our results align with Spracklen et al. (2015), who found that Côte d'Ivoire had some of the highest rates of deforestation inside and within 10 km of protected areas (0.5% year−1) in West Africa between 2000 and 2012.

    “Despite some methodological differences, our results align with those of Spracklen et al. (2015), who found that Côte d'Ivoire had some of the highest rates of deforestation inside and within 10 km of protected areas (0.5% year -1 ) in West Africa between 2000 and 2012.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Spracklen et al. (2015) source

      The Results (page not available) report elevated deforestation within protected areas in West Africa during 2000–2012, and describe analyses of surrounding buffers. The passages do not identify Côte d’Ivoire as having among the highest rates or give a 0.5% per year rate inside and within 10 km of its protected areas. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
  • Findingown data

    15,900 km2 (17%) of forest were lost between 2000 and 2019 in the pygmy hippopotamus distribution area.

    “Out of c. 89 600 km 2 in the year 2000, 15 900 km 2 (17%) of forest were lost, primarily to shifting agriculture (14 900 km 2 ).”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. 10
  • May combine two claims. 23
  • The quote only partly states this claim. 1

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

    Interpretationcitation

    Our results provide regional support for agricultural expansion and urban expansion being unambiguously linked to forest loss inside protected areas globally.

    “Our results provide regional support for agricultural expansion and 'Urban expansion' being unambiguously linked to forest loss inside protected areas globally (Heino et al. 2015).”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Heino et al. 2015 source

      The Results (page not available) report a positive association between agricultural land area and forest loss in protected forests, but agricultural land growth was associated only with loss in protected intact forests. The Introduction mentions proximity to urban areas in relation to deforestation generally, not urban expansion inside protected areas. The Conclusions caution that the statistical associations did not always correspond to causal explanations, so the claimed unambiguous global link is overstated. (LLM, conf=0.88)

      Experimental — accuracy not yet measured

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

    Premisecitation

    Cocoa plantations are common across West Africa, with Côte d'Ivoire producing 40-50% of the world's cocoa.

    “Our results indicate that industrial agriculture in the study area corresponds mainly to oil palm, tea and cocoa; however, cocoa plantations are common across West Africa, with Côte d'Ivoire producing 40-50% of the world's cocoa (Smith Dumont et al. 2014, Wessel & Quist-Wessel 2015).”
    Quote in the paperNot a substantial claim2 of 2 sources checked
    • cites Smith Dumont et al. 2014 source
    • cites Wessel & Quist-Wessel 2015 source

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

    Premisecitation

    The pygmy hippopotamus is listed as Endangered on the IUCN Red List of Threatened Species.

    “This includes animals listed as Endangered in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, such as the pygmy hippopotamus (Choeropsis liberiensis; Ransom et al. 2015, Ola & Benjamin 2019).”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites Ransom et al. 2015

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

    • cites Ola & Benjamin 2019 source

      Section 3, “West African Wetlands, Watersheds, and Forests” (page not provided), names the pygmy hippopotamus among the most threatened mammalian species. It does not state that the species has the specific IUCN Red List classification of Endangered. (LLM, conf=0.85)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingown data

    Oil palm contributes to considerable forest loss in the Upper Guinea Forest, primarily concentrated in southern Côte d'Ivoire.

    “Our results suggest that although oil palm contributes to considerable forest loss in the UGF, it has been primarily concentrated in southern Côte d'Ivoire.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Other protected areas in the region did not show negligible and driver-unrelated forest loss; forest loss in them was related to the identified drivers.

    “Our findings suggest that forest loss inside Taï (Côte d'Ivoire), Gola Rainforest (western Liberia) and Sapo (eastern Liberia) national parks is negligible and unrelated to the identified drivers assessed, which is not the case for other protected areas in the region.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Shifting agriculture activities are increasing in the area around Taï National Park, but they are more prominent to the north-west and south-west of the National Park.

    “our results suggest that 'Shifting agriculture' activities are increasing in the area, but they are more prominent to the north-west and south-west of the National Park (Fig. 4).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Most of the 'Urban expansion' areas were associated with existing settlements, infrastructure and industries (e.g., mining) and were close to roads.

    “Most of the 'Urban expansion' areas were associated with existing settlements, infrastructure and industries (e.g., mining) and were close to roads.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    Côte d'Ivoire lost 9825 km2 (61.8%) of net forest loss.

    “Côte d'Ivoire accounts for 57% of the pygmy hippopotamus distribution, out of which 9825 km 2 (61.8%) have been lost.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Côte d'Ivoire had the largest protected area network within the pygmy hippopotamus distribution (24,636 km2) and accounted for the largest area of forest loss within protected areas (3809 km2).

    “Côte d'Ivoire had the largest protected area network within the pygmy hippopotamus distribution (24 636 km 2 ) and accounted for the largest area of forest loss within protected areas (3809 km 2 ; Table 2).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Forest loss in Côte d'Ivoire was concentrated in the north and south within the study area, as well as near the Liberian border, and was sparse in the central region.

    “Here, forest loss was concentrated in the north and south within the study area, as well as near the Liberian border, and was sparse in the central region (Fig. 3).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    When normalized by the area within the pygmy hippopotamus distribution, Sierra Leone has lost more forest than Côte d'Ivoire or Liberia, followed by Côte d'Ivoire, Liberia and Guinea.

    “When normalized by the area within the pygmy hippopotamus distribution, Sierra Leone has lost more forest than Côte d'Ivoire or Liberia despite an order of magnitude difference in net loss, followed by Côte d'Ivoire, Liberia and Guinea (Table 1 & Appendix S1).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    'Shifting agriculture' activities account for 13,960 km2 in Côte d'Ivoire and Liberia, whereas Sierra Leone and Guinea have lost fewer than 1000 km2.

    “'Shifting agriculture' activities account for 13 960 km 2 in Côte d'Ivoire and Liberia, whereas Sierra Leone and Guinea have lost fewer than 1000 km 2 .”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Taï, Gola Rainforest and Sapo national parks account for 25% of the protected habitat in the pygmy hippopotamus distribution but only for 2% of the deforestation inside protected areas.

    “Our results indicate that Taï, Gola Rainforest and Sapo national parks account for 25% of the protected habitat in the pygmy hippopotamus distribution but only for 2% of the deforestation inside protected areas.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    'Urban expansion' was the second largest driver of forest loss inside protected areas and represented c.5% (254 km2) of all forest lost inside protected areas.

    “'Urban expansion' was the second largest driver of forest loss and represented c. 5% (254 km 2 ) of all forest lost inside protected areas.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    'Intensive agriculture' accounted for c.1% (144 km2) of the total area of forest loss, with most expansion occurring in Côte d'Ivoire and Liberia.

    “'Intensive agriculture' accounted for c. 1% (144 km 2 ) of the total area of forest loss, with most expansion occurring in Côte d'Ivoire and Liberia (Fig. 3 & Table 1).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Oil palm is primarily found in southern regions of Liberia and Côte d'Ivoire and extends from east to west in the pygmy hippopotamus distribution.

    “This crop is primarily found in southern regions of Liberia and Côte d'Ivoire and extends from east to west in the pygmy hippopotamus distribution (Fig. 3).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    When normalized, Liberia had lost the most forest within protected areas (33.7%), followed by Côte d'Ivoire (15.5%), whereas Guinea and Sierra Leone had lost the least both in net surface area and in proportion of their protected areas.

    “When the normalized area was considered, Liberia had lost the most forest (33.7%), followed by Côte d'Ivoire (15.5%), whereas Guinea and Sierra Leone had lost the least both in net surface area and in proportion of their protected areas (Fig. 4 & Table 2).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Forest loss inside Taï (Côte d'Ivoire), Gola Rainforest (western Liberia) and Sapo (eastern Liberia) national parks is negligible and unrelated to the identified drivers assessed.

    “Our findings suggest that forest loss inside Taï (Côte d'Ivoire), Gola Rainforest (western Liberia) and Sapo (eastern Liberia) national parks is negligible and unrelated to the identified drivers assessed, which is not the case for other protected areas in the region.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    'Shifting agriculture' was the main driver of forest loss inside protected areas across all countries, especially in Côte d'Ivoire and Liberia, which accounted for 94% (4568 km2) of total forest lost.

    “'Shifting agriculture' was the main driver of forest loss inside protected areas across all countries, but especially in Côte d'Ivoire and Liberia, which accounted for 94% (4568 km 2 ) of total forest lost.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Habitat loss in the pygmy hippopotamus distribution area is pervasive, primarily by shifting agriculture but also by urban expansion.

    “Our spatially explicit classification of deforestation drivers in the pygmy hippopotamus distribution area using the Sentinel-2 image archive and a random forest model shows that habitat loss primarily by 'Shifting agriculture' but also by 'Urban expansion' is pervasive.”
    Quote in the paperSubstantial claim

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

    Premisecitation

    The Upper Guinea Forest is considered a biodiversity hotspot.

    “Owing to high species endemism and rapid forest loss, the UGF is considered a biodiversity hotspot, but forest loss and degradation have continued (Myers 1988, Mittermeier et al. 2004, Curtis et al. 2018).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Myers 1988 source
    • cites Mittermeier et al. 2004

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

    • cites Curtis et al. 2018 source

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

    Premisecitation

    Protected areas in West African countries are generally less effective at preventing forest loss than in other regions, with deforestation often occurring both outside and inside protected areas.

    “Protected areas in West African countries are generally less effective at preventing forest loss than in other regions, with deforestation often occurring both outside and inside protected areas (Leberger et al 2020).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Leberger et al 2020

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

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

    Premisecitation

    The known distribution of the pygmy hippopotamus spans 140,221 km2 across Guinea, Sierra Leone, Liberia and Côte d'Ivoire.

    “The known distribution of the pygmy hippopotamus spans 140 221 km 2 across Guinea (2335 km 2 ), Sierra Leone (4814 km 2 ), Liberia (53 155 km 2 ) and Côte d'Ivoire (79 917 km 2 ; Fig. 1; IUCN 2015).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites IUCN 2015 source

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Forest loss in protected areas within the pygmy hippopotamus's range may lead to human-wildlife conflicts.

    “We have demonstrated that protected areas within the pygmy hippopotamus's range are affected by forest loss, and this may lead to human-wildlife conflicts.”
    Quote in the paperSubstantial claim

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

    Premisecitation

    Shifting agriculture was the main driver of forest loss in sub-Saharan Africa between 2001 and 2015.

    “For instance, shifting agriculture was the main driver of forest loss in sub-Saharan Africa between 2001 and 2015 (Curtis et al. 2018).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Curtis et al. 2018 source

  • May combine two claims.

    Interpretationreasoning

    Oil palm was the main crop in the 'Intensive agriculture' category and is considered one of the main industrial crops responsible for forest loss.

    “As the main crop in the 'Intensive agriculture' category, oil palm was easily identifiable from highresolution satellite images and is thus considered to be one of the main industrial crops responsible for forest loss.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Pygmy hippopotamus populations are and will continue to be threatened by the expansion of shifting agriculture, grazing and human settlements.

    “We provide evidence that pygmy hippopotamus populations are and will continue be threatened by the expansion of shifting agriculture, grazing and human settlements.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Côte d'Ivoire, Liberia, Sierra Leone and Guinea have lost 26%, 5.9%, 11% and 6.6% of humid primary forest since 2002, respectively.

    “Our results are consistent with Curtis et al. (2018), who reported 13% forest loss in Africa, and Global Forest Watch (Hansen et al. 2013), where Côte d'Ivoire, Liberia, Sierra Leone and Guinea have lost 26%, 5.9%, 11% and 6.6% of humid primary forest since 2002, respectively, meaning that the UGF has been heavily exploited in the past two decades (Table S3).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Hansen et al. 2013 source

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

    Premisecitation

    The Upper Guinea Forest once extended over more than 620,000 km2, from Guinea in the east to Nigeria in the west.

    “The UGF once extended over more than 620 000 km 2 , from Guinea in the east to Nigeria in the west, but unregulated activities such as logging and shifting agriculture were responsible for c. 90% of the forest loss between 1999 and 2013 (Bakarr et al. 2004, CILSS 2016).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Bakarr et al. 2004

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

    • cites CILSS 2016

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

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

    Interpretationcitation

    Our results are consistent with Curtis et al. (2018), who reported 13% forest loss in Africa.

    “Our results are consistent with Curtis et al. (2018), who reported 13% forest loss in Africa, and Global Forest Watch (Hansen et al. 2013), where Côte d'Ivoire, Liberia, Sierra Leone and Guinea have lost 26%, 5.9%, 11% and 6.6% of humid primary forest since 2002, respectively, meaning that the UGF has been heavily exploited in the past two decades (Table S3).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Curtis et al. 2018 source

  • May combine two claims.

    Study design and conductcitation

    The high prevalence of clouds in the region and the spectral similarity of forests and plantations often lead to driver misclassification.

    “The high prevalence of clouds in the region and the spectral similarity of forests and plantations often lead to driver misclassification (e.g., see Curtis et al. 2018).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Curtis et al. 2018 source
31 of 31

  • The paper relies on this without support.

    The spatial distribution of the drivers of forest loss in the Upper Guinea Forest, and spatially explicit information on proximate drivers within the pygmy hippopotamus range, are largely unknown or scarce.

    “Even though forest loss in the UGF is probably the major cause of the pygmy hippopotamus population decline, the spatial distribution of the drivers of forest loss in this area remains largely unknown.”

  • The paper relies on this without support.

    The Upper Guinea Forest has lost more than 90% of its original area since 1900.

    “The Upper Guinea Forest (UGF; West Africa), a global biodiversity hotspot, has lost more than 90% of its original area since 1900, threatening endemic species such as the endangered pygmy hippopotamus (Choeropsis liberiensis).”
2 of 2

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

  • Abstract understates the percentage of forest lost

    Minor

    Losing 15,900 km2 out of approximately 89,600 km2 is 17.7%, which rounds to 18%, not 17%.

    Reported 17 · recomputed 17.745536

  • Table 1 intensive-agriculture percentage is misstated

    Minor

    At the table's one-decimal precision, 144 km2 out of 15,901 km2 is 0.9%, not 1.0%.

    Reported 1 · recomputed 0.905603

2 of 2

Cites

Flagged first, then by citations

Research works printed but not linked: 14

  1. Eshuis, H (2011) Habitat preference and activity pattern of the pygmy hippopotamus analyzed by camera trapping and GIS. Thesis. Wageningen, The Netherlands: Wageningen University.
  2. UNEP-WCMC, IUCN (2021) Protected Planet Report 2020. Cambridge, UK: UNEP-WCMC; Gland, Switzerland: IUCN.
  3. 2017, Pastoral Livestock Farming in Sahel and West Africa
  4. 2014, Grow but Cherish Your Environment
  5. Bogui, 2016, Distribution of pygmy hippopotamus (Choeropsis liberiensis) in Taï National Park, Ivory Coast: influences of natural and anthropogenic factors, International Journal of Research in Biosciences, 5, 27
  6. Robinson, PT (1970) The status of the pygmy hippopotamus and other wildlife in West Africa. Thesis. East Lansing, MI, USA: Michigan State University.
  7. Robinson, 2017, The Pygmy Hippo Story: West Africa’s Enigma of the Rainforest
  8. 2016, Landscapes of West Africa: A Window on a Changing World
  9. Garteh, JC (2013) Studying the distribution and abundance of the Endangered pygmy hippopotamus (Choeropsis liberiensis) in and around the Gola Rainforest National Park in southeastern Sierra Leone. Thesis. Bo, Sierra Leone: Njala University.
  10. Mittermeier, 2004, Hotspots Revisited: Earth’s Biologically Richest and Most Endangered Terrestrial Ecoregions
  11. Pesaresi, 2015, GHS-BUILT R2015B – GHS Built-Up Grid, Derived from Landsat, Multitemporal (1975, 1990, 2000, 2014)
  12. 10.2305/IUCN.UK.2015-2.RLTS.T10032A18567171.en · DOI · Paper page
  13. Conway, AL (2013) Conservation of the pygmy hippopotamus (Choeropsis liberiensis) in Sierra Leone, West Africa. Thesis. Athens, GA, USA: University of Georgia.
  14. Hentschel, KM (1990) Untersuchung zu Status, Ökologie und Erhaltung des Zwergflusspferdes (Choeropsis liberiensis) in der Elfenbeinküste. Thesis. Braunschweig, Germany: Technische Universität Carolo-Wilhelmina zu Braunschweig.

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Related

Authors
Erazo-Mera, E., Younes, N., Horwood, P. F., Paris, D., Paris, M., & Murray, N.
Affiliations
  • Australian National University (AU)
  • Australian Institute of Tropical Health and Medicine (AU)
  • University of Pretoria (ZA)
  • James Cook University (AU)
Corresponding author
Murray, Nicholas
ORCID
Venue
Environmental Conservation
Publisher
Cambridge University Press (CUP)
Published
2023-12-06
Volume
51
Issue
1
Pages
55-63
ISSN
  • 0376-8929 (ISSN-L)
  • 1469-4387
DOI
10.1017/s0376892923000310
OpenAlex
W4389393230
Cited by
3
References
44
Citations by year
2026: 2 · 2025: 1
FWCI
0.34
Type
journal article
Language
en
Open access
Licence
Locations
  • Environmental Conservation (publishedVersion, cc-by)
  • ResearchOnline - JCU (James Cook University) (submittedVersion)
  • UpSpace Institutional Repository (University of Pretoria) (submittedVersion, cc-by)
  • ANU Open Research (Australian National University) (submittedVersion, cc-by)
Funders
European Space Agency
Topics
  • Physical Sciences › Environmental Science › Global and Planetary Change › Conservation, Biodiversity, and Resource Management
  • Physical Sciences › Environmental Science › Global and Planetary Change › Land Use and Ecosystem Services
  • Physical Sciences › Environmental Science › Ecology › Wildlife Ecology and Conservation
Keywords
forest loss, deforestation drivers, shifting cultivation, pygmy hippopotamus, Choeropsis liberiensis, Upper Guinea Forest, habitat loss, protected areas, Liberia, landscape conservation, land use change

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.

What counts as a claim ›How we measure confidence ›How we check this ›

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