Assessment Results
Incilius holdridgei
Holdridge's Toad
Order:
Anura
Family:
Bufonidae
Synonym(s):
Bufo holdridgei
Assessed for:
Costa Rica
on:
17 Apr 2020
by:
AArk/ASG Assessment Workshop
IUCN Global Red List:
Critically Endangered (CR)
National Red List:
(not assessed)
Distribution:
Costa Rica
Evolutionary Distinctiveness score:
10.00224666
William E. Duellman © 2010 Division of Herpetology, University of Kansas (1 of 7)
Recommended Conservation Actions:
Additional Comments:
A captive-breeding programme should be established for this species.
| 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 in view of the near-disappearance of its entire known population during the 1980s, probably involving chytridiomycosis. This species was considered Extinct until its rediscovery in 2009. The historical range of the species has been exhaustively searched in recent years (1987-2019), and it has only been recorded at two nearby sites in very low abundance. It is therefore suspected that the population survives in low numbers, possibly fewer than 50 mature individuals. |
| 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 previously known only from the type locality on Volcán Barva in the Cordillera Central, Costa Rica. The current known population is recorded from Alto del Roble in the Cordillera Central, close to the type locality. Individuals were recorded from two localities, 2 km apart (Abarca et al. 2010). The two sites where as of 2010 the species is known to persist are located in the Cerro Dantos and Jaguarundi Refuges, neither of which have the same protection status as a national park. |
| 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 | At the Parque Nacional Braulio Carrillo |
| 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 | The Holdridge Conservation project was establish in 2017 with this species as flag species for environmental education and outreach at local schools. |
| 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 | Expansion of effective forest preservation and continued management of existing protected areas is essential for the conservation of this species, maintaining (manage) small open areas and impeding the regroth of secondary forest helps on this species reproduction habitat needs. |
| 9 | In situ research | Is additional in situ research required to better understand the species, e.g. distribution, population trends, natural history etc.? | Yes | More information is needed on this species' distribution, population status, ecology, and threats. |
| 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 species is still being recorded at two sites, but in much lower abundance compared to historical numbers. The species is potentially threatened by expanding human settlements, changing land use, and degradation from tourism activities in parts of the national park and surrounding areas (V. Acosta pers. comm. September 2019). There is currently active land selling in the edge of the protected area of Parque Nacional Braulio Carrillo This species appears to have undergone rapid, dramatic declines across Costa Rica, including disappearances within undisturbed habitat, which has been associated with chytridiomycosis as observed in many other montane, steam-associated species across Mesoamerica. Climate change or the synergistic effects of multiple factors could be additional factors in the declines (Costa Rica Red List Assessment Workshop September 2019). The species is still being recorded at some sites, but in much lower numbers than historically. Currently it is seen that reverse of pasture to secondary forest could be a threat to the species. Also human settlement within the protected area Volcán Barva, recreational uses of off-road vehicles disturb the habitat of the species (Victor Acosta pers. Comm. Sept 2019). The species is susceptible to chytrid (M. O'Donnel and J. Abarca, pers comm, 2019) |
| 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 | There are no records of this species being utilized. |
| 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? | Unknown | This species was formerly common in appropriate habitat and during the breeding season, which coincides with the onset of the rainy season (2,765 males were seen visiting two pools in an eight-day period; Nowak and Robinson 1975). This species was not seen from 1987–2007 despite repeated searching (seven consecutive years of intensive searching to 2007: Héctor Zumbado, Andrés Vaughn, Warren Calvo, Adrián García unpublished data 2007) throughout its range. Nevertheless, the species was subsequently rediscovered in 2009 at two sites 2 km apart with adults, juveniles, and tadpoles (Abarca et al. 2010). Extensive searching has revealed less than five adult toads, and no large breeding aggregations such as were formerly reported for the species, suggesting a population of fewer than 50 adults (Abarca et al. 2010). Species has been monitored since 2008 every year in low densities - less than 20 sightings during the whole survey period (J. Abarca pers. comm. 2019) |
| 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? | No | |
| 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? | Yes | A captive-breeding program should be established for this species. |
| 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 | But there is no species within the country that could serve as so. |
| 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 | Although attempts were made by Juan Abarca and the Manchester Museum to kept the species. Tadpoles and recent metamorphose were brought into captivity but all of them died. |
| 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? | No | |
| 23 | Mandate | Is there an existing conservation mandate recommending the ex situ conservation of this taxon? | No | |
| 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? | Yes / probably | |
| 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:
AArk/ASG Assessment Workshop. 2020. Conservation Needs Assessment for Incilius holdridgei, Costa Rica.
https://www.conservationneeds.org/assessment/5119
Accessed 19 May 2024
