Taita Thrush (Turdus helleri): Revise global status?

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11 Responses to Taita Thrush (Turdus helleri): Revise global status?

  1. Mwangi Githiru says:

    Dear Sir / Madam
    I am not very clear how the AOO is actually computed, but it seems to me as if the proposed revision includes agricultural areas in between fragments that are presently occupied by the T. Thrush, which leads to a misleading exaggeration of the species range. Aside from the occasional records in the adjoining landscape, the fragments actually occupied by the species remain three (3), with a total area of about 350 ha (3.5 sq. km.) as previously cited. The agricultural matrix and human settlements in between these three forest remnants could inflate this to 20+ sq. km., but in my view, these areas cannot be considered as a meaningful part of the species’ range or effective AOO…

  2. Paul Gacheru says:

    I recommend that Taita Thrush be retained as CR status. Habitat suitability within Taita Hills for the species is highly fragmented restricting the species in a maximum of 3 forest fragments where it has been confirmed with a total area of forest fragments is approx 4sqKm. These forest fragments are far apart. Application of standardized approach of EOO and AOO may skew the vulnerability of the species in relation to available suitable habitat

  3. Paul Matiku says:

    Kindly retain Taita Thrush as critically endangered. The approach of determining the area is wrong. Ideally, every species can be assumed to occupy the entire planet but that is not sensible. In Taita, forest fragments are the only viable habitat. Areas between fragments do not count and should not be considered in the range calculation. Down listing this species without basing the justification on conservation success will make it edge closer to extinction.

  4. Sarah Havery says:

    Based on the current data and information available on this species, it is not appropriate to down-list this species to Endangered and it should remain as Critically Endangered. To the best of our knowledge the population is declining, it’s remaining habitat is highly fragmented and remains highly threatened. There is no clear conservation-based justification for the down-listing of this species. It seems there may have been a miscalculation of the AOO resulting in this proposed down-listing.

  5. To my views, the range size rather than the population size could be deceptive for species such as Turdus helleri. Our recent demographic studies that have involved consistent point counts and breeding surveys, revealed a population decline of T. helleri with sub-populations still confined in three forest fragments as of the year 2020 (unpublished). One of these host forest fragments have had a very small and unstable sub-population which at some point triggered translocation of individuals from other fragment. It remains a tiny, struggling sub-population to date. This therefore shrink the range of the estimated 3.5 km² in terms of presence of a viable sub-population in a given fragment. Even in the stronghold fragments, T. helleri have been observed to only exist in few forest pockets rather than being well distributed in an entire forest fragment. Breeding surveys for T.helleri conducted as latest as year 2021, have also revealed an extremely low breeding success which has significantly inhibited the population increase of the species. I would suggest that this species to NOT be down-listed until such a time when the ongoing conservation efforts which include habitat restoration, fragments connectivity etc. starts to bare fruits

  6. Nathaniel Mkombola says:

    As a member of the Taita Community, I do not support the idea of down listing Taita Thrush. As far as my understanding is concerned, the T. Thrush is restricted to the three Taita Hills’ forest fragments- Mbololo, Ngangao and Chawia with habitat suitability of about 4 km². These forest fragments with T. Thrush continue to face threats from clearance and degradation. Down listing T. Thrush will reverse the gains made in preventing its extinction.

  7. Red List Team (BirdLife International) says:

    Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested by so many people in commenting. The window for consultation is now closed. We will analyse and interpret the new information and post a preliminary decision on this species’s Red List status on this page in early July.

    Thank you once again,
    BirdLife Red List Team

  8. Red List Team (BirdLife International) says:

    Preliminary proposal

    Based on available information, our preliminary proposal for the 2021 Red List would be to adopt the proposed classifications outlined in the initial forum discussion.

    According to IUCN guidelines, the maximum AOO must be calculated by overlaying a 2 km x 2 km over the mapped range. It has been confirmed that the species is still present in all three forest blocks, and therefore the maximum AOO as calculated sensu IUCN is 20 sqkm.

    There is now a period for further comments until the final deadline in mid-July, after which the recommended categorisations will be put forward to IUCN.

    The final 2021 Red List categories will be published on the BirdLife and IUCN websites in December 2021, following further checking of information relevant to the assessments by both BirdLife and IUCN.

    • Paul Matiku says:

      Listen to conservation voices on the ground. The methodology used to determine the range is counting habitat not suitable for this species. A wrong decision today will haunt the decision makers tomorrow if the species disappears from our capability to ensure its survival. We are for ever worried about the ever reducing habitat and here you want to use mathematical formula to deceive the world? Take time before you insist on your approach. Even non scientists will tell you this species is in much more danger of extinction than 5 years ago. Kindly reconsider your decision. It is not this species to suffer but the method to be more studied to take into account the situation in the Taita. I want to report conservation success but here you want me to cheat that the efforts of my organization have yielded. Maintain the CR status for Taita Thrush

  9. I would like to comment on these criteria as I find them disturbing. First of all, it is fantastic to see the excellent comments and responses from our Kenyan colleagues as well as the one RSPB response. Secondly, while I have no personal experience with this species, I do have have experience with a number of the other species listed in this forum. I quote “According to IUCN guidelines, the maximum AOO must be calculated by overlaying a 2 km x 2 km over the mapped range. It has been confirmed that the species is still present in all three forest blocks, and therefore the maximum AOO as calculated sensu IUCN is 20 sqkm. ” I am a bit worried here — if you overlay a 2x2km over the mapped range, will that not include intervening habitat that this species does not occur in? If it does, then the criterion is too black and white, and does not consider the other factors. For example, a 20 km sq range for Endangered taxa may not be appropriate for all species, especially if long term monitoring is showing that this species is declining or if the habitat is being lost or deteriorating. Thus, the mapped range of occurrence is not a mapped range of abundance or mapped area of core breeding sites, where individuals outside the core area are sporadic visitors that move through the matrix and occupy the edge habitats for shorter periods. The data on this species from the Taita project is very robust and reliable–it is not conjecture. I recommend NOT down listing this taxon. Please enlighten me if I have misunderstood any of the criteria.

  10. Red List Team (BirdLife International) says:

    Recommended categorisation to be put forward to IUCN

    The final categorisation for this species has not changed. Taita Thrush is recommended to be listed as Endangered under Criteria A2b; B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v); C2a(i).

    The IUCN guidelines must be applied uniformly across all taxa, and therefore the maximum AOO must be calculated at the scale of a 2km x 2km square grid. Submitting the area of the remaining forest blocks as the AOO value will not be accepted by IUCN. Prior to this assessment, the range map was updated based on a map of the forest blocks supplied by L. Lens in litt. (2019), and it has since been confirmed in the discussion thread that the species still occurs in the three forest blocks as mapped. Therefore, as it has been explained above, the maximum AOO for this species, as calculated according to IUCN guidelines, is 20 km2.

    A continuing decline in habitat and AOO has been taken into account in the assessment, as the species meets subcriteria b(ii,iii). A declining population trend is covered by Criterion A and Criterion C, under which this species qualifies as Endangered, as explained in the topic.

    Many thanks for everyone who contributed to the 2021 GTB Forum process. The final 2021 Red List categories will be published on the BirdLife and IUCN websites in December 2021, following further checking of information relevant to the assessments by both BirdLife and IUCN.

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