Since 2012 we detected high numbers of the Buff-breasted Sandpiper in floodplain savannas of Colombia (AKA Llanos) where extensive cattle ranching is the main economic activity. Extensive outreach efforts directed toward ranchers and municipality officials led to the designation of the WHSRN Site Sabanas de Paz de Ariporo y Trinidad in February 2020. This WHSRN site supports 1.25% of the Buff-breasted Sandpiper population on northbound migration. That site consists of 61,657 hectares where cattle ranching has been practiced for more than four generations of twelve families. The potential agricultural expansion projects would be associated with a conversión threshold of approximately 75% of área of the Llanos. Currently, 12% of the Llanos natural landscape has been converted to agriculture, plantain (14%), corn (10%), soybean (7%), and cassava (3%). That is evident if we consider that the rice cultivated area in the Llanos was 167,457 hectares in 2013 and 273,002 hectares in 2023. In fact, one of the Llanos departments is Casanare where the 93,878 hectares of rice cultivated in 2013 and 187,789 hectares in 2023. Precisely a WHSRN site is located in Casanare. Tha hábitat loss is impacting this shorebird in the Llanos of Colombia but the monitoring program has just started and a population trend is not detected yet.
The species is considered Vulnerable at the national level in Paraguay, and officially listed as “Amenazada” due to loss of key stopover habitat in the Bahía de Asunción and the Chaco. Prior to the construction of the Costanera coastal road in 2010, the Bahía de Asunción was a globally important stopover site for the species, but the complete loss of habitat for the species has resulted in only occasional individuals being recorded since. The species is primarily a passage migrant through Paraguay, mainly during southbound migration, which just occasional records during the boreal winter months, and no evidence that Paraguay is a regular part of its winter range.
As noted above, the declines observed during the migration surveys reported in Smith et al. (2023) are likely to be poor estimates for this species, as the species rarely migrates along the Atlantic Flyway where most of the surveys were conducted,. Also, the Atlantic Flyway is the route that young of the year are more likely to take (and the results in Smith et al. 2023 are from fall migration). Thus these declines might be simply a reflection of poor reproduction as opposed to loss of adults from the population. Of course, repeated years of low reproduction also are not good but are not as worrying as adult population loss.
This petition also indicates that the population estimate has been revised upward by 10x it’s previous count of 56,000 to around 550,000 birds based on PRISM surveys on the Canadian Arctic breeding grounds. The very low number of survey plots, the coarse habitat strata used, and the unique habits used by the species makes large scale extrapolations potentially fraught with error. Other statistically-derived data from spring migration surveys in Texas show much lower population estimates of birds, with <26,000 birds estimated (J. Lyons, et al.). Also, it is difficult to imagine 560,000 birds present on the winter grounds based on a large amount of on-the-ground survey work conducted throughout that area. The real population number maybe more than 56,000 but is likely much below 560,000. Thus the concern for the species having a small population size should remain a factor in ranking this species.
In addition, as noted in the petition and in several comments, there are increasing threats occurring at key stopover sites in Colombia, Paraguay, and also in Bolivia, where government incentive programs may change the Beni Savannah to agriculture. Further, recent work in Texas shows a very high dependence on Turf Farms during spring and fall migration, where the species maybe exposed to herbicides and pesticides in this heavily managed crop (Tara Rodkey, Manuscript submitted).
It is true that the species appears to have "adapted" to agricultural fields, especially those in short stature (<5-8 cm tall), when its native grasslands are lost. But like the Turf farms, it is unknown whether these sites reflect ecological sinks due to contaminant exposure. Only one study tried to evaluate contaminants (Strum et al. 2010) and found some exposure to cholinesterase-inhibiting contaminants in rice fields in Argentina in 2006. It is unknown whether new contaminants (e.g., neonicotinoids) are affecting the species.
PRISM surveys in the Arctic National Wildlife Refuge in northwestern Alaska showed a non-significant population decline from 2002/2004 with 7,684 (+/- SE = 5,167) adults to 2019/2022 with 2,386 (=/- SE = 1,466) adults (S. Brown et al. unpubl. data). The probability of decline for the species was estimated at around 82%.
PRISM surveys at the Teshekpuk Lake Special area in northern Alaska showed a small change (5%) in number of adults detected on 53 plots surveyed n 2007/2008 and 2023 (S. Brown, et al. unpubl. data). Another year of surveys will be conducted in 2024 after which population estimates will be made for a better comparison across time.
All and all, I think there are valid concerns for the species given some information that suggests declines in breeding adults, lower reproduction in recent years (assumes Atlantic flyway reflects total population), its uncertain but potentially still small population size, and its high reliance on key stopover sites and a migration corridor that are either already agriculture or being converted to agriculture, and thus exposing the birds to contaminants.
A last comment, the map showed is grossly inaccurate based on recent tracking work on the species. The wintering range is much smaller (see McCarthy et al. 2020), and the migration routes are also very narrow, especially going north and south through the Midwest of the United States and Canada (see Lanctot et al. 2016). While the Lanctot et al. (2016) paper shows data from only 3 birds, subsequently GPS tracking data confirm this route by over 50 tagged birds (T. Tibbitts and R. Lanctot, unpubl. data).
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 3 May 2024. We will now analyse and interpret all information, and we will post a preliminary decision on this species’ Red List status on this page on 3 May 2024, when discussions will re-open.
Based on available information, our preliminary proposal for the 2024 Red List would be to adopt the proposed classifications outlined in the initial forum discussion.
There is now a period for further comments until the final deadline on 13 May 2024, after which the recommended categorisations will be put forward to IUCN.
The final 2024 Red List categories will be published on the BirdLife and IUCN websites in October 2024, following further checking of information relevant to the assessments by both BirdLife and IUCN.
In key Brazilian sites no clear populational trends were noted.
https://www.cambridge.org/core/journals/bird-conservation-international/article/abs/trends-and-population-estimate-of-the-threatened-buffbreasted-sandpiper-calidris-subruficollis-wintering-in-coastal-grasslands-of-southern-brazil/A02E3365EEB01743392FA153F5BD1CF3
Since 2012 we detected high numbers of the Buff-breasted Sandpiper in floodplain savannas of Colombia (AKA Llanos) where extensive cattle ranching is the main economic activity. Extensive outreach efforts directed toward ranchers and municipality officials led to the designation of the WHSRN Site Sabanas de Paz de Ariporo y Trinidad in February 2020. This WHSRN site supports 1.25% of the Buff-breasted Sandpiper population on northbound migration. That site consists of 61,657 hectares where cattle ranching has been practiced for more than four generations of twelve families. The potential agricultural expansion projects would be associated with a conversión threshold of approximately 75% of área of the Llanos. Currently, 12% of the Llanos natural landscape has been converted to agriculture, plantain (14%), corn (10%), soybean (7%), and cassava (3%). That is evident if we consider that the rice cultivated area in the Llanos was 167,457 hectares in 2013 and 273,002 hectares in 2023. In fact, one of the Llanos departments is Casanare where the 93,878 hectares of rice cultivated in 2013 and 187,789 hectares in 2023. Precisely a WHSRN site is located in Casanare. Tha hábitat loss is impacting this shorebird in the Llanos of Colombia but the monitoring program has just started and a population trend is not detected yet.
The species is considered Vulnerable at the national level in Paraguay, and officially listed as “Amenazada” due to loss of key stopover habitat in the Bahía de Asunción and the Chaco. Prior to the construction of the Costanera coastal road in 2010, the Bahía de Asunción was a globally important stopover site for the species, but the complete loss of habitat for the species has resulted in only occasional individuals being recorded since. The species is primarily a passage migrant through Paraguay, mainly during southbound migration, which just occasional records during the boreal winter months, and no evidence that Paraguay is a regular part of its winter range.
As noted above, the declines observed during the migration surveys reported in Smith et al. (2023) are likely to be poor estimates for this species, as the species rarely migrates along the Atlantic Flyway where most of the surveys were conducted,. Also, the Atlantic Flyway is the route that young of the year are more likely to take (and the results in Smith et al. 2023 are from fall migration). Thus these declines might be simply a reflection of poor reproduction as opposed to loss of adults from the population. Of course, repeated years of low reproduction also are not good but are not as worrying as adult population loss.
This petition also indicates that the population estimate has been revised upward by 10x it’s previous count of 56,000 to around 550,000 birds based on PRISM surveys on the Canadian Arctic breeding grounds. The very low number of survey plots, the coarse habitat strata used, and the unique habits used by the species makes large scale extrapolations potentially fraught with error. Other statistically-derived data from spring migration surveys in Texas show much lower population estimates of birds, with <26,000 birds estimated (J. Lyons, et al.). Also, it is difficult to imagine 560,000 birds present on the winter grounds based on a large amount of on-the-ground survey work conducted throughout that area. The real population number maybe more than 56,000 but is likely much below 560,000. Thus the concern for the species having a small population size should remain a factor in ranking this species.
In addition, as noted in the petition and in several comments, there are increasing threats occurring at key stopover sites in Colombia, Paraguay, and also in Bolivia, where government incentive programs may change the Beni Savannah to agriculture. Further, recent work in Texas shows a very high dependence on Turf Farms during spring and fall migration, where the species maybe exposed to herbicides and pesticides in this heavily managed crop (Tara Rodkey, Manuscript submitted).
It is true that the species appears to have "adapted" to agricultural fields, especially those in short stature (<5-8 cm tall), when its native grasslands are lost. But like the Turf farms, it is unknown whether these sites reflect ecological sinks due to contaminant exposure. Only one study tried to evaluate contaminants (Strum et al. 2010) and found some exposure to cholinesterase-inhibiting contaminants in rice fields in Argentina in 2006. It is unknown whether new contaminants (e.g., neonicotinoids) are affecting the species.
PRISM surveys in the Arctic National Wildlife Refuge in northwestern Alaska showed a non-significant population decline from 2002/2004 with 7,684 (+/- SE = 5,167) adults to 2019/2022 with 2,386 (=/- SE = 1,466) adults (S. Brown et al. unpubl. data). The probability of decline for the species was estimated at around 82%.
PRISM surveys at the Teshekpuk Lake Special area in northern Alaska showed a small change (5%) in number of adults detected on 53 plots surveyed n 2007/2008 and 2023 (S. Brown, et al. unpubl. data). Another year of surveys will be conducted in 2024 after which population estimates will be made for a better comparison across time.
All and all, I think there are valid concerns for the species given some information that suggests declines in breeding adults, lower reproduction in recent years (assumes Atlantic flyway reflects total population), its uncertain but potentially still small population size, and its high reliance on key stopover sites and a migration corridor that are either already agriculture or being converted to agriculture, and thus exposing the birds to contaminants.
A last comment, the map showed is grossly inaccurate based on recent tracking work on the species. The wintering range is much smaller (see McCarthy et al. 2020), and the migration routes are also very narrow, especially going north and south through the Midwest of the United States and Canada (see Lanctot et al. 2016). While the Lanctot et al. (2016) paper shows data from only 3 birds, subsequently GPS tracking data confirm this route by over 50 tagged birds (T. Tibbitts and R. Lanctot, unpubl. data).
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 3 May 2024. We will now analyse and interpret all information, and we will post a preliminary decision on this species’ Red List status on this page on 3 May 2024, when discussions will re-open.
Preliminary proposal
Based on available information, our preliminary proposal for the 2024 Red List would be to adopt the proposed classifications outlined in the initial forum discussion.
There is now a period for further comments until the final deadline on 13 May 2024, after which the recommended categorisations will be put forward to IUCN.
The final 2024 Red List categories will be published on the BirdLife and IUCN websites in October 2024, following further checking of information relevant to the assessments by both BirdLife and IUCN.