Assessment Results
Arthroleptis krokosua
Krokosua Squeaking Frog, West African Giant Squeaker
Order:
Anura
Family:
Arthroleptidae
Synonym(s):
Assessed for:
Ghana
on:
27 Sep 2021
by:
AArk/ASG Ghana Assessment Workshop
Authors:
Adum, G., Kouamé, N.G., Ofori-Boateng, C. and Penner, J.
IUCN Global Red List:
Critically Endangered (CR)
National Red List:
(not assessed)
Distribution:
Cote d'Ivoire (Presence Uncertain), Ghana, Guinea, Liberia (Presence Uncertain)
Evolutionary Distinctiveness score:
16.60940992
Recommended Conservation Actions:
Additional Comments:
| Question # | Short Name | Question Text | Response | Comments |
| 1 | Extinction risk | Current IUCN Red List category. [Data obtained from the IUCN Red List.] | Critically Endangered (CR) | Listed as Critically Endangered because there are believed to be fewer than 250 mature individuals, with 90% of these occurring within the subpopulation found in the Sui River Forest Reserve, and a continuing decline in the number of mature individuals caused by habitat loss from logging activities, farming (especially for cocoa), illegal plantations and small-scale mining. |
| 2 | Possibly extinct | Is there a strong possibility that this species might be extinct in the wild? | No / unlikely | |
| 3 | Phylogenetic significance | The taxon’s Evolutionary Distinctiveness (ED) score, as generated by the ZSL EDGE program. (These data are not editable by Assessors). | ED value < 20 | |
| 4 | Protected habitat | Is a population of at least 50% of the individuals of the taxon included within a well-managed or reliably protected area or areas? | No / unlikely | This species was known from the Krokosua Hills Forest Reserve, at 300 m asl, and is observed in the neighbouring Sui River Forest Reserve, both in southwestern Ghana (Ernst et al. 2008, R. Ernst pers. comm. April 2010, Adum et al. 2011, Sandberger-Loua et al. 2018). The original habitat in the Krokosua Hills was destroyed in 2016, and the species is no longer believed to occur there (G. Adum pers. comm. November 2018). Although this species currently occurs in forest reserve in Ghana, and a single individual has been recorded from Mount Nimba in Guinea is a World Heritage Site, these are still subject to habitat degradation and loss because of human encroachment, so much so that Mount Nimba is currently listed in UNESCO's World Heritage in Danger list (UNESCO 2013). |
| 5 | Habitat for reintroduction, conservation translocation or supplementation | Does enough well-managed and reliably protected habitat exist, either within or outside of currently protected areas that is suitable for conservation translocation, including population restoration or conservation introduction? | Yes / probably | This species was known from the Krokosua Hills Forest Reserve, at 300 m asl, and is known from the neighbouring Sui River Forest Reserve, both in southwestern Ghana (Ernst et al. 2008, R. Ernst pers. comm. April 2010, Adum et al. 2011, Sandberger-Loua et al. 2018). However, the original habitat in the Krokosua Hills was destroyed in 2016, and the species is no longer believed to occur there (G. Adum pers. comm. November 2018). This species is known to survive in two sites (one in Ghana and one in Guinea), which are considered to be two threat-defined locations. The area between the two known locations requires more surveys as the new site at Mt. Nimba makes an occurrence into Côte d’Ivoire (or at least a former occurrence) very likely, for example in the Mountains of Man (M.-O. Rödel pers. comm. August 2013, Sandberger-Loua et al. 2018). However, due to its very specific habitat requirements (dense leave litter on steep slopes in pristine forest), there are unlikely to be many, perhaps any, undiscovered subpopulations (G. Adum, pers. comm., October 2018). It is likely that currently, there is enough habitat in the Sui River Forest Reserve, however it is essential that this is protected in the future (G. Adum, pers. comm., September 2021). Due to its specific habitat requirements, the area of suitable habitat available in Ghana is tiny (G. Adum pers. comm. October 2018). |
| 6 | Previous reintroductions | Have reintroduction or translocation attempts been made in the past for this species? | No | |
| 7 | In situ conservation activities | Are any in situ conservation actions currently in place for this species? (Only required if a Red List Assessment has not been completed, or if new actions have been implemented since the last Red List Assessment. (Information from the Conservation Actions section of the Red List assessment should be reviewed and considered when answering this question.). | Yes / probably | This species still occurs in one forest reserve in Ghana, which is still subject to habitat degradation and loss because of human encroachment. There is ongoing work occurring with local communities since 2009, including the development of an education centre to communicate the importance of this species (G. Adum, pers. comm., September 2021). Planting of trees is also an ongoing activity within this reserve since 2009 which has resulted in some reforestation. |
| 8 | In situ conservation activities | Are additional in situ conservation actions required to help conserve this species in the wild (e.g. habitat restoration and/or protection, control of invasive species, national legislation etc.)? | Yes / probably | Urgent reserve management and enforcement is required to protect the species' habitat. Current work with local communities to gain their support for saving the species, including by preventing wildfires from entering its habitat should be maintained. |
| 9 | In situ research | Is additional in situ research required to better understand the species, e.g. distribution, population trends, natural history etc.? | Yes | Further survey work is needed to determine the extent of this species' distribution and its population status, as well as its ecology. |
| 10 | Threat mitigation | Are the threats facing the taxon, including any new and emerging threats not considered in the IUCN Red List, potentially reversible? | Threats unlikely to be reversed in time to prevent further decline / extinction | The vegetation of both Ghanaian reserves (Krokosua Hills Forest Reserve and the Sui River Forest Reserve) has been severely disturbed by both past and current logging activities, fragmentation, farming (especially for cocoa), illegal plantations and small-scale mining (R. Ernst pers. comm. April 2010, Adum et al. 2011, G. Adum pers. comm. October 2018). The habitat in Krokosua Hills Forest Reserve (its type locality) has now been completely lost due to wildfires which have destroyed the species’ leaf-litter microhabitat (G. Adum pers. comm. October 2018). While the fires had been ongoing prior to this, the complete destruction of the type locality occurred in a big fire in 2016 (G. Adum pers. comm. November 2018). This species occurs in a very small area in Ghana which is now under human encroachment pressure (Ernst et al. 2008, G. Adum pers. comm. October 2018), which is occurring at an alarming rate (R. Ernst pers. comm. April 2010, G. Adum pers. comm. October 2018). Multiple threats currently exist in the Sui River Forest Reserve. Large-scale selective logging (both legally and illegally) and deforestation for cacao plantations (G. Adum, pers. comm., September 2021) - in 2021, the government allowed 15 ha of the 333.9 km² Sui River Forest Reserve to be cleared (G. Adum and J. Penner, pers. comm., September 2021). Other threats include the use of agrochemicals, gold mining, encroachment due to over-population, wildfires as a result of slash and burn activities and the spread of the invasive weed (Chromolaena odorata), (Ghana RLA/CNA assessment workshop, 2021). Large-scale selective logging is occurring throughout the reserve, which has resulted in areas becoming more accessible and led to a recent increase in illegal commercial logging activities (G. Adum, pers. comm., September 2021). |
| 11 | Over-collection from the wild | Is the taxon suffering from collection within its natural range, either for food, for the pet trade or for any other reason, which threatens the species’ continued persistence in the wild? | No / unlikely | |
| 12 | Population recovery | Is the known population of this species in the wild large enough to recover naturally, without ex situ intervention if threats are mitigated? | No / unlikely | In Ghana the species is believed to be extinct in its type locality, the Krokosua Hills Forest Reserve (G. Adum pers. comm. October 2018). It survives in very small numbers in the Sui River Forest Reserve, the largest number ever found being 14 individuals over two days when it was looked for with huge manpower (Owusu-Gyamfi and Adum, 2014, G. Adum pers. comm. October 2018). Surveys at this locality have recorded the species in 2009 (Adum et al. 2011), 2013 (Adum et al. 2015), 2015 (Platt 2015, Adum 2016) and 2016 (Adum et al. 2017). About 95% of individuals found are juveniles and sub-adults, and it is believed that very few survive to adulthood (G. Adum pers. comm. October 2018). Two gravid females were found in 2018 (G. Adum pers. comm. September 2021). Given its rarity, the limited available habitat, and the small number of animals surviving to adulthood, it is reasonable to presume that the number of mature individuals could be less than 250. |
| 13 | Action plans | Does an Action Plan for the species already exist, or is one currently being developed? | No | |
| 14 | Biological distinctiveness | Does the taxon exhibit a distinctive reproductive mode, behaviour, aspect of morphology or physiology, within the Order to which it belongs (e.g. Anura, Passeriformes etc.)? | No aspect of biology known to be exceptional | |
| 15 | Cultural/socio-economic importance | Does the taxon have a special human cultural value (e.g. as a national or regional symbol, in a historic context, featuring in traditional stories) or economic value (e.g. food, traditional medicine, tourism) within its natural range or in a wider global context? | Yes | This species was named after the Krokosua Hills Forest Reserve and the local people take pride in this (G. Adum, pers. comm., September 2021). |
| 16 | Scientific importance | Is the species vital to current or planned research other than species-specific ecology/biology/conservation within the Order to which it belongs (e.g. Anura, Passeriformes etc.) e.g. human medicine, climate change, environmental pollutants and conservation science? | No research dependent on this species | |
| 17 | Ex situ research | Does conserving this species (or closely related species) in situ depend upon research that can be most easily carried out ex situ? | No | |
| 18 | Ex situ conservation activities | Is any ex situ research or other ex situ conservation action currently in place for this species? (Information from the Conservation Actions section of the Red List assessment should be reviewed and considered when answering this question.) | No / unlikely | |
| 19 | Husbandry analog required | If an ex situ rescue program is recommended for this species, would an analog species be required to develop husbandry protocols first? | Yes / probably | Other species of Squeaker frogs (e.g. Arthroleptis poecilonotus complex) from pristine forests could be a good analog for this species (G. Adum and J. Penner, pers. comm., September 2021). |
| 20 | Husbandry analog | Do the biological and ecological attributes of this species make it suitable for developing husbandry regimes for more threatened related species? i.e. could this species be used in captivity to help to develop husbandry and breeding protocols which could be used for a similar, but more endangered species at a later stage? | No | |
| 21 | Captive breeding | Has this species been successfully bred and/or maintained in captivity? | Not held in captivity to date | |
| 22 | Conservation education/ecotourism potential | Is the species especially diurnal, active or colourful, or is there an interesting or unusual aspect of its ecology that make it particularly suitable to be an educational ambassador for conservation of the species in the range country, either in zoos or aquariums or within ecotourism activities? | Yes | The size of this species, its golden coloration and the fact that is it so threatened makes this a good species for education purposes (G. Adum, pers. comm., September 2021). |
| 23 | Mandate | Is there an existing conservation mandate recommending the ex situ conservation of this taxon? | Yes | Consideration should also be given to whether or not a captive-breeding program might be required (IUCN Red List, 2018, 2021). |
| 24 | Range State approval | If an ex situ initiative was proposed for this species, would it be supported (and approved) by the range State (either within the range State or out-of-country ex situ)? | Yes / probably | |
| 25 | Founder specimens | Are sufficient animals of the taxon available or potentially available (from wild or captive sources) to initiate an ex situ program, if one was recommended? | No / unlikely | |
| 26 | Taxonomic status | Has a complete taxonomic analysis of the species in the wild been carried out, to fully understand the functional unit you wish to conserve (i.e. have species limits been determined)? | Yes |
Citation:
Adum, G., Kouamé, N.G., Ofori-Boateng, C. and Penner, J. 2021. Conservation Needs Assessment for Arthroleptis krokosua, Ghana
(AArk/ASG Ghana Assessment Workshop).
https://www.conservationneeds.org/assessment/6913
Accessed 18 May 2024
