Regarding the species’ dependence on acacia scrub – yes, it is reasonable to expect a decline in abundance in line with the loss of Whistling Thorn Vachellia drepanolobium and V. seyal. During surveys in the Wembere Steppe (2003) and Serengeti (2005-06), half of all Maasai Apalis sightings were made in stands of Whistling Thorn where densities exceeded 1000 stems per ha. Such densities occurred at only 8% of vegetation survey points in the Serengeti and at 13% of survey points in the Wembere (Shaw et al. 2009).
A high proportion of the apalis’s global range lies within protected areas associated with the Serengeti ecosystem. While this might suggest that much of its habitat is reasonably secure, it’s worth noting that the level of threat posed by Big-headed Ants to Whistling Thorn is contingent on the presence of large herbivores (Riginos et al. 2015). Whistling Thorn is more vulnerable to browsing by elephant and giraffe in areas where Big-headed Ants have eliminated Crematogaster ants, which otherwise protect the plant. Hence, ironically, Big-headed Ant invasions could pose a greater threat to the apalis’s habitat within protected areas – where large herbivores are abundant – than on unprotected land, where the latter are increasingly scarce, or absent.
The account notes that ‘it is likely that all individuals of this species are contained within a single subpopulation’. Accordingly, the map shows its range to be unbroken between the Serengeti ecosystem, the Wembere Steppe and Nyahua Swamp Area, to the SW. However, the most southerly sighting I am aware of in the Serengeti-Mara was at Ndutu-Makao in 2004, by A.R.E. Sinclair. The most northerly individual recorded during the 2003 Wembere Steppe survey was at a location 142 km SW of the southern Serengeti record. Driving north from the Wembere Steppe to the Serengeti, via Lake Eyasi, we saw no large stands of whistling thorn, nor the bird itself.
Regarding the range map, if no records exist within this c. 142 km gap it would seem parsimonious to show the species as ‘possibly extant’ in that area (i.e. in green hatching), rather than as a native resident, and to assume that there are two subpopulations.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments until 25 April 2025. We will now analyse and interpret the information, and we will post a preliminary decision on this species’ Red List category on this page on 25 April 2025, when discussions will re-open.
We thank P. Shaw for the comment. The distribution description and range map will be corrected accordingly to reflect possibly extant areas between the Serengeti and the Wembere Steppe, and the threats section of the assessment to highlight the issue with Big-headed Ants in protected areas in particular. Although acknowledging the lack of suitable habitat between the Serengeti and the Wembere Steppe, the distance between the southernmost record in the Serengeti and the northern most record in the Wembere Steppe could still be considered within acceptable dispersal distance for juveniles. Considering the uncertainty this brings on the number of subpopulations present (as defined by the IUCN Guidelines), the assessment will be changed to include 1-2 subpopulations. Based on available information, our preliminary proposal for the 2025 Red List would be to adopt the proposed classification outlined in the initial forum discussion.
There is now a period for further comments until the final deadline on 4 May 2025, after which the recommended categorisations will be put forward to IUCN.
The final 2025 Red List categories will be published on the BirdLife and IUCN websites in October 2025, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret the information, and a final decision on this species’ Red List category will be posted on this page on 12 May 2025.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. Maasai Apalis is recommended to be listed as Vulnerable under Criterion C2a(ii).
Many thanks for everyone who contributed to the 2025.2 GTB Forum process. The final Red List categories will be published on the BirdLife and IUCN websites in October 2025, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Regarding the species’ dependence on acacia scrub – yes, it is reasonable to expect a decline in abundance in line with the loss of Whistling Thorn Vachellia drepanolobium and V. seyal. During surveys in the Wembere Steppe (2003) and Serengeti (2005-06), half of all Maasai Apalis sightings were made in stands of Whistling Thorn where densities exceeded 1000 stems per ha. Such densities occurred at only 8% of vegetation survey points in the Serengeti and at 13% of survey points in the Wembere (Shaw et al. 2009).
A high proportion of the apalis’s global range lies within protected areas associated with the Serengeti ecosystem. While this might suggest that much of its habitat is reasonably secure, it’s worth noting that the level of threat posed by Big-headed Ants to Whistling Thorn is contingent on the presence of large herbivores (Riginos et al. 2015). Whistling Thorn is more vulnerable to browsing by elephant and giraffe in areas where Big-headed Ants have eliminated Crematogaster ants, which otherwise protect the plant. Hence, ironically, Big-headed Ant invasions could pose a greater threat to the apalis’s habitat within protected areas – where large herbivores are abundant – than on unprotected land, where the latter are increasingly scarce, or absent.
The account notes that ‘it is likely that all individuals of this species are contained within a single subpopulation’. Accordingly, the map shows its range to be unbroken between the Serengeti ecosystem, the Wembere Steppe and Nyahua Swamp Area, to the SW. However, the most southerly sighting I am aware of in the Serengeti-Mara was at Ndutu-Makao in 2004, by A.R.E. Sinclair. The most northerly individual recorded during the 2003 Wembere Steppe survey was at a location 142 km SW of the southern Serengeti record. Driving north from the Wembere Steppe to the Serengeti, via Lake Eyasi, we saw no large stands of whistling thorn, nor the bird itself.
Regarding the range map, if no records exist within this c. 142 km gap it would seem parsimonious to show the species as ‘possibly extant’ in that area (i.e. in green hatching), rather than as a native resident, and to assume that there are two subpopulations.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments until 25 April 2025. We will now analyse and interpret the information, and we will post a preliminary decision on this species’ Red List category on this page on 25 April 2025, when discussions will re-open.
Preliminary proposal
We thank P. Shaw for the comment. The distribution description and range map will be corrected accordingly to reflect possibly extant areas between the Serengeti and the Wembere Steppe, and the threats section of the assessment to highlight the issue with Big-headed Ants in protected areas in particular. Although acknowledging the lack of suitable habitat between the Serengeti and the Wembere Steppe, the distance between the southernmost record in the Serengeti and the northern most record in the Wembere Steppe could still be considered within acceptable dispersal distance for juveniles. Considering the uncertainty this brings on the number of subpopulations present (as defined by the IUCN Guidelines), the assessment will be changed to include 1-2 subpopulations. Based on available information, our preliminary proposal for the 2025 Red List would be to adopt the proposed classification outlined in the initial forum discussion.
There is now a period for further comments until the final deadline on 4 May 2025, after which the recommended categorisations will be put forward to IUCN.
The final 2025 Red List categories will be published on the BirdLife and IUCN websites in October 2025, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret the information, and a final decision on this species’ Red List category will be posted on this page on 12 May 2025.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. Maasai Apalis is recommended to be listed as Vulnerable under Criterion C2a(ii).
Many thanks for everyone who contributed to the 2025.2 GTB Forum process. The final Red List categories will be published on the BirdLife and IUCN websites in October 2025, following further checking of information relevant to the assessments by both BirdLife and IUCN.