10 thoughts on “Blue-billed Curassow (Crax alberti)”
The justification for downlisting the species seems solid and, based on the information available, the best course of action. I would like to state, however, that extrapolating the abundances from a protected area and assuming constant abundance across space will likely result in an overoptimistic scenario. It is very safe to assume that density in other populations, particularly in areas where anthropogenic pressures are more evident, are likely lower. However, I am aware that only by estimating density in other local populations we will finally be able to get a much more realistic estimate of population size. Until that information is collected and evidence points to another direction, the species should remain listed as EN.
Recent camera trap surveys conducted in the Río Frío Valley suggest an estimated population of approximately 80–120 mature individuals inhabiting this area. Our estimate is based on calculated RAI for the species from surveys covering approximately 20% of the remaining intact habitat and then extrapolated across the estimated remaining suitable habitat in the valley (approx. 15,000 ha). Our findings are significantly higher than previous estimates for this river valley, surpassing the formerly largest known subpopulation in Tayrona National Park (ca. 50 individuals). This revised estimate meaningfully increases the total number of mature individuals known from the Magdalena department (previously 104–240) and contributes substantially to the global population estimate. Additionally, our findings indicate that the Blue-billed Curassow is capable of persisting—and even thriving—in well-developed secondary forests, a notable contrast to previous assumptions that the species was largely dependent on undisturbed primary forest. This ecological flexibility significantly broadens the scope of what can be considered suitable habitat, particularly in regions where primary forest has been extensively converted or degraded. As a result, the potential extent of suitable habitat across the species’ range may be larger than previously thought, which in turn could support a higher global population. While further research is needed to determine thresholds of habitat quality and long-term viability in these landscapes, this finding provides a more optimistic outlook for the species’ persistence in fragmented and regenerating areas. As such, this new information provides credible justification for downlisting the species from CR to EN , as it indicates that at least one subpopulation now exceeds 50 mature individuals and total numbers may be higher than previously assumed.
That being said, caution is still warranted. Our surveys were conducted in an area with relatively low disturbance and active conservation management, which likely contributes to higher local density. Extrapolating these figures across the species’ range, particularly into more fragmented or degraded habitats, risks overestimating total abundance, given that carrying capacity and anthropogenic pressures vary significantly across sites. Moreover, there is growing concern about increased illicit activities in the Río Frío Valley, including the increased presence of paramilitary groups, which may lead to elevated hunting pressure on this subpopulation in the coming years. As such, while downlisting appears appropriate based on current evidence, it should be accompanied by a recognition of current data limitations and a clear need for expanded population assessments across other parts of the species’ range and protection of healthy subpopulations. Further density estimates in unprotected or heavily impacted areas will be critical for refining the species’ conservation status in the future.
Dear Red list team, I have undertaken a review of available data and new information collected in recent years to assess the conservation status (especially IUCN Red List status) of Crax alberti in Colombia. While full information is available in the peer-reviewed article “Cortes, A., Mosquera, L.G. & Salaman, P. (2025) Extinction of the Blue-billed Curassow Crax alberti is imminent: the last stand for a pre-Columbian icon. Conservation Colombiana 30 (1): 3-12.” The paper will be published later this month, but I post the abstract online and attach the full article and ask that you do not circulate until it is published. Thank you. Abstract:
The Critically Endangered Blue-billed Curassow (Crax alberti) is endemic to central and northern Colombia and historically ranged across 13,500 km2 of tropical forest. Since 1999, the expansion of illicit coca plantations has led to the colonization and deforestation of the last four major forest wilderness areas in this region: Medio Magdalena, Bajo Cauca, Serranía de las Quinchas, and Sinú watershed. Following the 2016 peace process, deforestation rates increased significantly across all regions. Consequently, Crax alberti has experienced a rapid decline in its area of occupancy and population due to habitat loss and hunting, affecting both unprotected and protected areas of Colombia. Over the past 25 years, Crax alberti has lost 92.8% of its viable habitat (from 12,003 km2 to 1,150 km2) due to deforestation and fragmentation, resulting in a population decrease of 95.5%, leaving an estimated 1,085 mature individuals by 2024. The species qualifies as Critically Endangered under the IUCN Red List criterion (A2(b,c,d) & A3(b,c,d). Currently, only one potentially viable population remains, consisting of an estimated 138 mature individuals in El Paujíl ProAves Reserve located in Serranía de las Quinchas. However, this subpopulation faces significant threats from hunting and the abrupt termination of U.S. government funding that supported Reserve Rangers to protect this species. It is projected that Crax alberti may become extinct in the wild by 2050 unless immediate measures are taken to mitigate forest losses and persecution.
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 the contributors for the information shared in the above comments and greatly appreciate the email allowing us to view the manuscript of the relevant submitted paper. New information will be incorporated into the updated species factsheet.
However, the comments received highlight a contradiction in understanding the status of the species. Alex Cortes presents data suggesting extremely rapid population reductions have taken place since 2000, assuming absence from forest fragments less than <10 km2 (at least for the 2024 data: a figure showing the mapped areas used for the comparison would benefit the manuscript) and generating a novel historical population estimate for the year 2000 based on intact forest area. Kyle Waites presents camera trap data revealing the species can persist in secondary forest and indicating that the suitable habitat area may be larger than assumed. The revised estimate for the Río Frío Valley of 80-120 mature individuals is notable as the manuscript supplied by Alex Cortes assumes no sustainable population in this area, nor anywhere away from a handful at Tayrona for this part of the range. The assumption that the species can only be in large intact blocks of forest is key to the very rapid rates of reduction presented yet does not appear to hold here. However, it is important to note that there is protection for the species in place at the site surveyed by Kyle Waites.
It has been demonstrated that hunting pressure can determine density rather than forest intactness and the species can display preference for disturbed areas (Eschucha et al. 2021), in agreement with the camera trap data. This may weaken the link between large intact blocks of forest and presence/absence of the species.
The proposal here does assume rates of population reduction are potentially far greater than the rates of recorded forest cover loss due to fragmentation and hunting. But the rates of reduction derived in the manuscript are extremely rapid. It is unclear that the area values used for the two time periods are directly comparable. Presumably the method used to restrict suitable habitat in 2024 to those areas larger than 10 km2 was also applied to the initial forest area as well, but this is not clear from the manuscript. If not, then the values cannot be compared. As these determine the calculated population sizes that generate the rates of population reduction presented, it is crucial to be explicit on how the figures were derived (as noted, forest loss from Global Forest Watch for 2000-2023 was 21-30%). How hunting impact has been considered is also unclear.
The manuscript received also suggests that the largest subpopulation may exceed 250 mature individuals, the threshold for Endangered under Criterion C2a(i), suggesting that under this Criterion the species may be Vulnerable. Further detail is needed on subpopulation division: while there could be sizable numbers in Paramillo National Park and Serrania de San Lucas, there may also be very few indeed given the lack of confirmed recent records.
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, but with a view to revising the decision pending further detail on the method used to generate the extremely rapid reported rates of population reduction indicated in the paper supplied by Alex Cortes, and on the derivation of subpopulation sizes.
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.
We received the following comment from Christian Olaciregui while the forum was temporarily closed:
“Camera trap surveys in the Serranía de San Jacinto/Montes de María between 2018 and 2021 failed to detect the species. Cameras were deployed at several areas with intact forest, including the Los Colorados Flora and Fauna Sanctuary and Alto de las Campanas, where the species was collected in 1949. Given this evidence, the species is possible extirpated from this area and this likelihood of the existence of ths subpopulation is extremely low.
In regards to the dowlisting, I suggest being cautious as the estimated size of the population is based on an extrapolation from a single site where there is protection and therefore not representative of the species´s whole distribution. Also, the species population is highly fragmented and therefore the genetic diversity could be compromised. However, the assessment of the species under the criteria is solid. It would be important to very accurate about current state and requirements.”
ADVERTENCIA FIRME:
Dadas las contundentes afirmaciones poblacionales y ecológicas de WAITES, basadas en estudios con cámaras trampa, que sugieren que Crax alberti prospera en el bosque secundario y que la especie podría no estar en peligro inminente, solicito que se proporcione más información o una publicación al respecto antes de extrapolar la afirmación de WAITES a esta evaluación actual. Es importante revisar los métodos de estudio utilizados para estimar esta población excepcionalmente grande en un pequeño valle de 8700 ha (por debajo de los 1000 m) que alberga solo un bloque forestal de 12,7 km² y otros bosques muy fragmentados y perturbados (esta área también es objeto de caza). Esta área por debajo de los 1000 metros de altitud se encuentra completamente fuera del Parque Nacional Sierra Nevada de Santa Marta y no está protegida. No encontré ningún artículo publicado sobre la encuesta de trampas de cámara WAITES, sin embargo, un póster publicado en la Conferencia Nacional de la Asociación Estadounidense de Cuidadores de Zoológicos (https://tinyurl.com/3vm9pfk9) declaró la metodología “Las ubicaciones de muestreo se eligieron al azar, sin embargo, para aumentar la tasa de éxito de cada cámara, todas se instalaron a lo largo de senderos de juego o cerca de una fuente de agua”. Esto verifica que la ubicación sesgada de las trampas de cámara invalida cualquier posible estimación significativa de la población y, por lo tanto, resultó en datos de población poco confiables.
El póster no presentó fotos de trampas de cámara de la especie en 2018, aunque dos años después del estudio, una publicación de Instagram confirmó la primera foto de trampa de cámara Crax de febrero de 2000 (https://tinyurl.com/4tuexd2v), lo que sugiere tentativamente que incluso la ubicación sesgada de las trampas de cámara produjo pocos registros. Si bien no existe ninguna publicación, los datos de eBird de WAITES (https://tinyurl.com/5f73svn7) muestran solo cuatro registros de Crax alberti sin cámaras trampa en el valle del Río Frío a lo largo de tres años (2020-2023), aunque desconozco el esfuerzo realizado. Si bien la especie está presente en Río Frío, seguimos creyendo que las estimaciones poblacionales originales publicadas por Strewe et al. (2010), utilizando una metodología estricta de transectos (auditiva y de avistamientos), que concluyó que ocho parejas en este valle se encontraban en tres pequeñas subpoblaciones fragmentadas (1, 3 y 4 parejas), sigue siendo la estimación más precisa sin la evidencia cuantitativa de WAITES.
La Fundación ProAves propone respetuosamente a Birdlife International evitar cometer un grave error. La propuesta es que se nos permita organizar una reunión nacional en Colombia dentro de dos meses para que, por consenso y con la participación de todas las autoridades académicas y ambientales, podamos decidir sobre el verdadero estado de conservación de Crax alberti.
Inenglish…
STRONG ADVISORY:
Given the bold population and ecological statements by WAITES from camera trap surveys that imply Crax alberti is thriving in secondary forest and species may not be at imminent threat, I request more information or a publication on this be provided before extrapolating WAITES statement to this current assessment. It is important to review the survey methods used to estimate this exceptionally large population estimate in a small 8,700 ha valley (below 1,000 m) that holds just one forest block of 12.7km2 and other heavily fragmented and disturbed forests (this area is also hunted). This area below 1000 meters elevation is entirely outside of the Sierra Nevada de Santa Marta National Park and unprotected. I found no published paper on WAITES camera trap survey, however, a Poster published at the American Association of Zoo Keepers National Conference (https://tinyurl.com/3vm9pfk9) stated the methodology “Sampling locations were chosen at random, however, to increase the success rate of each camera, all were installed along game trails or near a water source.” This verifies that the biased location of camera traps invalidates any possible meaningful population estimates and hence resulted in unreliable population data. The poster presented no camera trap photos of the species in 2018, although two years into the study an Instagram post confirmed the first camera trap photo Crax photo from Feb 2000 (https://tinyurl.com/4tuexd2v), which tentatively suggests that even biased placement of camera traps yielded few records. While there is no publication, WAITES own eBird data (https://tinyurl.com/5f73svn7) shows only 4 non-camera trap records of Crax alberti in the Rio Frio valley across 3 years (2020-2023) although I have no idea of the effort undertaken. While the species is present in Rio Frio, we still believe the original published population estimates by Strewe et al (2010) using strict transect methodology (auditive and sightings) concluded 8 pairs in this valley in 3 small fragmented subpopulations (1,3,4 pairs) is still the most accurate estimate without quantitative evidence from WAITES.
The ProAves Foundation respectfully proposes to Birdlife International that we avoid making a serious mistake. The proposal is that we be allowed to organize a national meeting in Colombia within two months so that, by consensus and with the participation of all academic and environmental authorities, we can decide on the true Crax alberti conservation status.
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
Following further review, the recommended categorisation for this species has been changed. Blue-billed Curassow is now recommended to be listed as Critically Endangered under Criterion A4cd.
Further information has been received from Alex Cortes and Kyle Waites. The discussion prompted a re-analysis of the potential area of suitable habitat within the Rio Frio study area and a revision of the likely population size here to 40-60 mature individuals in 70-80 km2 of suitable habitat. Importantly hunting pressure here is reduced through an informal coalition of farmers who recognise the cultural and ecological importance of the species.
However, the evidence supplied by Alex Cortes demonstrates that this sentiment does not extend across the remaining range. Further investigation into the recent rapid fragmentation of remaining suitable lowland forests support the suggestion that habitat degradation and loss have had a greater impact on the population size than indicated by forest cover loss data alone. While a very few large areas of forest remain, even these contain holes from small-scale agricultural clearance. Crucially this indicates that access for hunting is available across almost all remaining habitat. Notable new information includes a recent camera trapping effort in the Serrania de las Quinchas that support an extremely rapid decline here (outside of El Paujil reserve) due to hunting. Alongside the evidence from C. Olaciregui that the species has been extirpated from Montes de Maria and Serrania de San Jacinto (when the original proposal viewed persistence here as reassurance that loss rates were not as severe as feared), as well as the occupancy modelling study predicting extirpation of a seemingly typical remnant population within less than 50 years (Valencia et al. 2023), it appears that the additional impact of both fragmentation but especially hunting warrant a greater consideration.
The conclusion is that recent very severe fragmentation leaves almost the whole population at high risk from hunting, which is continuing and has caused a sudden recent reduction in the population even in the surroundings of El Paujil reserve. Considering this, the rate of population reduction for the current three generation period, commencing after 2016 to coincide with the acceleration of forest loss, fragmentation and increased settlement in forested areas, is suspected to fall between 55-85 %, and the species is proposed to be listed as Critically Endangered.
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.
The justification for downlisting the species seems solid and, based on the information available, the best course of action. I would like to state, however, that extrapolating the abundances from a protected area and assuming constant abundance across space will likely result in an overoptimistic scenario. It is very safe to assume that density in other populations, particularly in areas where anthropogenic pressures are more evident, are likely lower. However, I am aware that only by estimating density in other local populations we will finally be able to get a much more realistic estimate of population size. Until that information is collected and evidence points to another direction, the species should remain listed as EN.
Recent camera trap surveys conducted in the Río Frío Valley suggest an estimated population of approximately 80–120 mature individuals inhabiting this area. Our estimate is based on calculated RAI for the species from surveys covering approximately 20% of the remaining intact habitat and then extrapolated across the estimated remaining suitable habitat in the valley (approx. 15,000 ha). Our findings are significantly higher than previous estimates for this river valley, surpassing the formerly largest known subpopulation in Tayrona National Park (ca. 50 individuals). This revised estimate meaningfully increases the total number of mature individuals known from the Magdalena department (previously 104–240) and contributes substantially to the global population estimate. Additionally, our findings indicate that the Blue-billed Curassow is capable of persisting—and even thriving—in well-developed secondary forests, a notable contrast to previous assumptions that the species was largely dependent on undisturbed primary forest. This ecological flexibility significantly broadens the scope of what can be considered suitable habitat, particularly in regions where primary forest has been extensively converted or degraded. As a result, the potential extent of suitable habitat across the species’ range may be larger than previously thought, which in turn could support a higher global population. While further research is needed to determine thresholds of habitat quality and long-term viability in these landscapes, this finding provides a more optimistic outlook for the species’ persistence in fragmented and regenerating areas. As such, this new information provides credible justification for downlisting the species from CR to EN , as it indicates that at least one subpopulation now exceeds 50 mature individuals and total numbers may be higher than previously assumed.
That being said, caution is still warranted. Our surveys were conducted in an area with relatively low disturbance and active conservation management, which likely contributes to higher local density. Extrapolating these figures across the species’ range, particularly into more fragmented or degraded habitats, risks overestimating total abundance, given that carrying capacity and anthropogenic pressures vary significantly across sites. Moreover, there is growing concern about increased illicit activities in the Río Frío Valley, including the increased presence of paramilitary groups, which may lead to elevated hunting pressure on this subpopulation in the coming years. As such, while downlisting appears appropriate based on current evidence, it should be accompanied by a recognition of current data limitations and a clear need for expanded population assessments across other parts of the species’ range and protection of healthy subpopulations. Further density estimates in unprotected or heavily impacted areas will be critical for refining the species’ conservation status in the future.
Dear Red list team, I have undertaken a review of available data and new information collected in recent years to assess the conservation status (especially IUCN Red List status) of Crax alberti in Colombia. While full information is available in the peer-reviewed article “Cortes, A., Mosquera, L.G. & Salaman, P. (2025) Extinction of the Blue-billed Curassow Crax alberti is imminent: the last stand for a pre-Columbian icon. Conservation Colombiana 30 (1): 3-12.” The paper will be published later this month, but I post the abstract online and attach the full article and ask that you do not circulate until it is published. Thank you. Abstract:
The Critically Endangered Blue-billed Curassow (Crax alberti) is endemic to central and northern Colombia and historically ranged across 13,500 km2 of tropical forest. Since 1999, the expansion of illicit coca plantations has led to the colonization and deforestation of the last four major forest wilderness areas in this region: Medio Magdalena, Bajo Cauca, Serranía de las Quinchas, and Sinú watershed. Following the 2016 peace process, deforestation rates increased significantly across all regions. Consequently, Crax alberti has experienced a rapid decline in its area of occupancy and population due to habitat loss and hunting, affecting both unprotected and protected areas of Colombia. Over the past 25 years, Crax alberti has lost 92.8% of its viable habitat (from 12,003 km2 to 1,150 km2) due to deforestation and fragmentation, resulting in a population decrease of 95.5%, leaving an estimated 1,085 mature individuals by 2024. The species qualifies as Critically Endangered under the IUCN Red List criterion (A2(b,c,d) & A3(b,c,d). Currently, only one potentially viable population remains, consisting of an estimated 138 mature individuals in El Paujíl ProAves Reserve located in Serranía de las Quinchas. However, this subpopulation faces significant threats from hunting and the abrupt termination of U.S. government funding that supported Reserve Rangers to protect this species. It is projected that Crax alberti may become extinct in the wild by 2050 unless immediate measures are taken to mitigate forest losses and persecution.
Saludos, Alex
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 the contributors for the information shared in the above comments and greatly appreciate the email allowing us to view the manuscript of the relevant submitted paper. New information will be incorporated into the updated species factsheet.
However, the comments received highlight a contradiction in understanding the status of the species. Alex Cortes presents data suggesting extremely rapid population reductions have taken place since 2000, assuming absence from forest fragments less than <10 km2 (at least for the 2024 data: a figure showing the mapped areas used for the comparison would benefit the manuscript) and generating a novel historical population estimate for the year 2000 based on intact forest area. Kyle Waites presents camera trap data revealing the species can persist in secondary forest and indicating that the suitable habitat area may be larger than assumed. The revised estimate for the Río Frío Valley of 80-120 mature individuals is notable as the manuscript supplied by Alex Cortes assumes no sustainable population in this area, nor anywhere away from a handful at Tayrona for this part of the range. The assumption that the species can only be in large intact blocks of forest is key to the very rapid rates of reduction presented yet does not appear to hold here. However, it is important to note that there is protection for the species in place at the site surveyed by Kyle Waites.
It has been demonstrated that hunting pressure can determine density rather than forest intactness and the species can display preference for disturbed areas (Eschucha et al. 2021), in agreement with the camera trap data. This may weaken the link between large intact blocks of forest and presence/absence of the species.
The proposal here does assume rates of population reduction are potentially far greater than the rates of recorded forest cover loss due to fragmentation and hunting. But the rates of reduction derived in the manuscript are extremely rapid. It is unclear that the area values used for the two time periods are directly comparable. Presumably the method used to restrict suitable habitat in 2024 to those areas larger than 10 km2 was also applied to the initial forest area as well, but this is not clear from the manuscript. If not, then the values cannot be compared. As these determine the calculated population sizes that generate the rates of population reduction presented, it is crucial to be explicit on how the figures were derived (as noted, forest loss from Global Forest Watch for 2000-2023 was 21-30%). How hunting impact has been considered is also unclear.
The manuscript received also suggests that the largest subpopulation may exceed 250 mature individuals, the threshold for Endangered under Criterion C2a(i), suggesting that under this Criterion the species may be Vulnerable. Further detail is needed on subpopulation division: while there could be sizable numbers in Paramillo National Park and Serrania de San Lucas, there may also be very few indeed given the lack of confirmed recent records.
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, but with a view to revising the decision pending further detail on the method used to generate the extremely rapid reported rates of population reduction indicated in the paper supplied by Alex Cortes, and on the derivation of subpopulation sizes.
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.
We received the following comment from Christian Olaciregui while the forum was temporarily closed:
“Camera trap surveys in the Serranía de San Jacinto/Montes de María between 2018 and 2021 failed to detect the species. Cameras were deployed at several areas with intact forest, including the Los Colorados Flora and Fauna Sanctuary and Alto de las Campanas, where the species was collected in 1949. Given this evidence, the species is possible extirpated from this area and this likelihood of the existence of ths subpopulation is extremely low.
In regards to the dowlisting, I suggest being cautious as the estimated size of the population is based on an extrapolation from a single site where there is protection and therefore not representative of the species´s whole distribution. Also, the species population is highly fragmented and therefore the genetic diversity could be compromised. However, the assessment of the species under the criteria is solid. It would be important to very accurate about current state and requirements.”
ADVERTENCIA FIRME:
Dadas las contundentes afirmaciones poblacionales y ecológicas de WAITES, basadas en estudios con cámaras trampa, que sugieren que Crax alberti prospera en el bosque secundario y que la especie podría no estar en peligro inminente, solicito que se proporcione más información o una publicación al respecto antes de extrapolar la afirmación de WAITES a esta evaluación actual. Es importante revisar los métodos de estudio utilizados para estimar esta población excepcionalmente grande en un pequeño valle de 8700 ha (por debajo de los 1000 m) que alberga solo un bloque forestal de 12,7 km² y otros bosques muy fragmentados y perturbados (esta área también es objeto de caza). Esta área por debajo de los 1000 metros de altitud se encuentra completamente fuera del Parque Nacional Sierra Nevada de Santa Marta y no está protegida. No encontré ningún artículo publicado sobre la encuesta de trampas de cámara WAITES, sin embargo, un póster publicado en la Conferencia Nacional de la Asociación Estadounidense de Cuidadores de Zoológicos (https://tinyurl.com/3vm9pfk9) declaró la metodología “Las ubicaciones de muestreo se eligieron al azar, sin embargo, para aumentar la tasa de éxito de cada cámara, todas se instalaron a lo largo de senderos de juego o cerca de una fuente de agua”. Esto verifica que la ubicación sesgada de las trampas de cámara invalida cualquier posible estimación significativa de la población y, por lo tanto, resultó en datos de población poco confiables.
El póster no presentó fotos de trampas de cámara de la especie en 2018, aunque dos años después del estudio, una publicación de Instagram confirmó la primera foto de trampa de cámara Crax de febrero de 2000 (https://tinyurl.com/4tuexd2v), lo que sugiere tentativamente que incluso la ubicación sesgada de las trampas de cámara produjo pocos registros. Si bien no existe ninguna publicación, los datos de eBird de WAITES (https://tinyurl.com/5f73svn7) muestran solo cuatro registros de Crax alberti sin cámaras trampa en el valle del Río Frío a lo largo de tres años (2020-2023), aunque desconozco el esfuerzo realizado. Si bien la especie está presente en Río Frío, seguimos creyendo que las estimaciones poblacionales originales publicadas por Strewe et al. (2010), utilizando una metodología estricta de transectos (auditiva y de avistamientos), que concluyó que ocho parejas en este valle se encontraban en tres pequeñas subpoblaciones fragmentadas (1, 3 y 4 parejas), sigue siendo la estimación más precisa sin la evidencia cuantitativa de WAITES.
La Fundación ProAves propone respetuosamente a Birdlife International evitar cometer un grave error. La propuesta es que se nos permita organizar una reunión nacional en Colombia dentro de dos meses para que, por consenso y con la participación de todas las autoridades académicas y ambientales, podamos decidir sobre el verdadero estado de conservación de Crax alberti.
Inenglish…
STRONG ADVISORY:
Given the bold population and ecological statements by WAITES from camera trap surveys that imply Crax alberti is thriving in secondary forest and species may not be at imminent threat, I request more information or a publication on this be provided before extrapolating WAITES statement to this current assessment. It is important to review the survey methods used to estimate this exceptionally large population estimate in a small 8,700 ha valley (below 1,000 m) that holds just one forest block of 12.7km2 and other heavily fragmented and disturbed forests (this area is also hunted). This area below 1000 meters elevation is entirely outside of the Sierra Nevada de Santa Marta National Park and unprotected. I found no published paper on WAITES camera trap survey, however, a Poster published at the American Association of Zoo Keepers National Conference (https://tinyurl.com/3vm9pfk9) stated the methodology “Sampling locations were chosen at random, however, to increase the success rate of each camera, all were installed along game trails or near a water source.” This verifies that the biased location of camera traps invalidates any possible meaningful population estimates and hence resulted in unreliable population data. The poster presented no camera trap photos of the species in 2018, although two years into the study an Instagram post confirmed the first camera trap photo Crax photo from Feb 2000 (https://tinyurl.com/4tuexd2v), which tentatively suggests that even biased placement of camera traps yielded few records. While there is no publication, WAITES own eBird data (https://tinyurl.com/5f73svn7) shows only 4 non-camera trap records of Crax alberti in the Rio Frio valley across 3 years (2020-2023) although I have no idea of the effort undertaken. While the species is present in Rio Frio, we still believe the original published population estimates by Strewe et al (2010) using strict transect methodology (auditive and sightings) concluded 8 pairs in this valley in 3 small fragmented subpopulations (1,3,4 pairs) is still the most accurate estimate without quantitative evidence from WAITES.
The ProAves Foundation respectfully proposes to Birdlife International that we avoid making a serious mistake. The proposal is that we be allowed to organize a national meeting in Colombia within two months so that, by consensus and with the participation of all academic and environmental authorities, we can decide on the true Crax alberti conservation status.
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
Following further review, the recommended categorisation for this species has been changed. Blue-billed Curassow is now recommended to be listed as Critically Endangered under Criterion A4cd.
Further information has been received from Alex Cortes and Kyle Waites. The discussion prompted a re-analysis of the potential area of suitable habitat within the Rio Frio study area and a revision of the likely population size here to 40-60 mature individuals in 70-80 km2 of suitable habitat. Importantly hunting pressure here is reduced through an informal coalition of farmers who recognise the cultural and ecological importance of the species.
However, the evidence supplied by Alex Cortes demonstrates that this sentiment does not extend across the remaining range. Further investigation into the recent rapid fragmentation of remaining suitable lowland forests support the suggestion that habitat degradation and loss have had a greater impact on the population size than indicated by forest cover loss data alone. While a very few large areas of forest remain, even these contain holes from small-scale agricultural clearance. Crucially this indicates that access for hunting is available across almost all remaining habitat. Notable new information includes a recent camera trapping effort in the Serrania de las Quinchas that support an extremely rapid decline here (outside of El Paujil reserve) due to hunting. Alongside the evidence from C. Olaciregui that the species has been extirpated from Montes de Maria and Serrania de San Jacinto (when the original proposal viewed persistence here as reassurance that loss rates were not as severe as feared), as well as the occupancy modelling study predicting extirpation of a seemingly typical remnant population within less than 50 years (Valencia et al. 2023), it appears that the additional impact of both fragmentation but especially hunting warrant a greater consideration.
The conclusion is that recent very severe fragmentation leaves almost the whole population at high risk from hunting, which is continuing and has caused a sudden recent reduction in the population even in the surroundings of El Paujil reserve. Considering this, the rate of population reduction for the current three generation period, commencing after 2016 to coincide with the acceleration of forest loss, fragmentation and increased settlement in forested areas, is suspected to fall between 55-85 %, and the species is proposed to be listed as Critically Endangered.
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.