Relatively common in the Pantanal plains and occurs exclusively in open areas such as wet meadows, as well as fields with Andropogon bicornis. These areas have been undergoing constant changes due to fires that occur annually in the region. The loss of wintering sites due to the replacement of native fields by cultivated exotic pastures and criminal fires are the main threats to the species in the Pantanal.
The Bobolink is predicted to experience a net loss of its breeding range of 32% by 2080.
Bateman, B.L., Wilsey, C., Taylor, L., Wu, J., LeBaron, G.S. and Langham, G., 2020. North American birds require mitigation and adaptation to reduce vulnerability to climate change. Conservation Science and Practice, 2(8), p.e242.
The Bobolink (Dolichonyx oryzivorus) in the Colombian Llanos depends on natural savannas, especially floodable savannas, which are increasingly being converted into rice fields. In the past, rice farmers had conflicts with Bobolinks because the birds would take advantage of rice crops close to harvest, feeding on the grains in large numbers. Currently, such conflicts no longer occur in Colombia, as the timing of rice harvest does not coincide with the Bobolink’s migration period.
However, although there is no recent evidence of farmers taking drastic measures such as killing Bobolinks in their fields, it is possible that such conflict could resurface as rice cultivation areas continue to expand in departments such as Casanare and Arauca, both located in the Llanos region.
It is also concerning that the natural savannas used by Bobolinks between April and May are being rapidly transformed. This period coincides with the soil preparation phase for rice cultivation, which involves the application of pesticides and the burning of vegetation. These activities typically continue until the rains arrive in the last weeks of April, marking the beginning of rice planting.
Consequently, the rapid northward migration of the Bobolink may be affected in the department of Casanare, as these birds are increasingly exposed to agrochemicals, water scarcity, and limited food resources due to the loss of their natural savanna habitat.
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 contributors for the information shared in the above comments. This information will be incorporated into the updated species factsheet. Information regarding specific regional threats is particularly helpful.
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.
Regarding drivers of decline, there are two newer publications that could be consulted:
1. Renfrew et al. 2019. A full life cycle conservation plan for Bobolink
2. COSEWIC 2022. Bobolink: COSEWIC Assessment and Status Report.
Both of these publications assessed threats across the annual cycle for Bobolink; COSEWIC (2022) used the IUCN-CMP unified threats classification. Both cite the primary threats on the breeding grounds to be conversion of grasslands (hayfields, pastures, prairie) to row-crop agriculture (or other unsuitable habitat types) and incidental mortality from mowing/haying operations; conversion of grassland on the overwintering grounds is similarly affecting the species. Conversely, hunting and collecting was ranked as a low threat that may not have substantial population-level impacts (albeit unknown how many are being trapped). Agricultural effluents (pesticides) were identified as the second highest threat after annual and perennial non-timber crops in COSEWIC (2022).
The BTOW publication, though dated 2020, hasn’t been updated since 2015. These more recent publications may help to better frame the important threats to the species. Incidental mortality from more frequent and earlier haying should be noted.
Grasslands National Park has in-person and/or ARU point count data on BOBO. Please contact the Ecological Integrity Monitoring or Wildlife Ecologists for the data.
Also, regarding the 2022 publication reference provided by Kathy St. Laurent above, note sections related to “Historical influence of human activity” and “Breeding Ground Habitat – General Description”. These sections provide some historical context for current population declines, particularly in the eastern portion of the range.
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. Bobolink is recommended to be listed as Near Threatened, approaching thresholds under Criteria A2bcd+4bcd.
We would like to thank contributors for the additional information provided in the above comments. Information on threats is especially helpful and will be incorporated into the updated species factsheet.
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.
Relatively common in the Pantanal plains and occurs exclusively in open areas such as wet meadows, as well as fields with Andropogon bicornis. These areas have been undergoing constant changes due to fires that occur annually in the region. The loss of wintering sites due to the replacement of native fields by cultivated exotic pastures and criminal fires are the main threats to the species in the Pantanal.
The Bobolink is predicted to experience a net loss of its breeding range of 32% by 2080.
Bateman, B.L., Wilsey, C., Taylor, L., Wu, J., LeBaron, G.S. and Langham, G., 2020. North American birds require mitigation and adaptation to reduce vulnerability to climate change. Conservation Science and Practice, 2(8), p.e242.
The Bobolink (Dolichonyx oryzivorus) in the Colombian Llanos depends on natural savannas, especially floodable savannas, which are increasingly being converted into rice fields. In the past, rice farmers had conflicts with Bobolinks because the birds would take advantage of rice crops close to harvest, feeding on the grains in large numbers. Currently, such conflicts no longer occur in Colombia, as the timing of rice harvest does not coincide with the Bobolink’s migration period.
However, although there is no recent evidence of farmers taking drastic measures such as killing Bobolinks in their fields, it is possible that such conflict could resurface as rice cultivation areas continue to expand in departments such as Casanare and Arauca, both located in the Llanos region.
It is also concerning that the natural savannas used by Bobolinks between April and May are being rapidly transformed. This period coincides with the soil preparation phase for rice cultivation, which involves the application of pesticides and the burning of vegetation. These activities typically continue until the rains arrive in the last weeks of April, marking the beginning of rice planting.
Consequently, the rapid northward migration of the Bobolink may be affected in the department of Casanare, as these birds are increasingly exposed to agrochemicals, water scarcity, and limited food resources due to the loss of their natural savanna habitat.
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 contributors for the information shared in the above comments. This information will be incorporated into the updated species factsheet. Information regarding specific regional threats is particularly helpful.
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.
Regarding drivers of decline, there are two newer publications that could be consulted:
1. Renfrew et al. 2019. A full life cycle conservation plan for Bobolink
2. COSEWIC 2022. Bobolink: COSEWIC Assessment and Status Report.
Both of these publications assessed threats across the annual cycle for Bobolink; COSEWIC (2022) used the IUCN-CMP unified threats classification. Both cite the primary threats on the breeding grounds to be conversion of grasslands (hayfields, pastures, prairie) to row-crop agriculture (or other unsuitable habitat types) and incidental mortality from mowing/haying operations; conversion of grassland on the overwintering grounds is similarly affecting the species. Conversely, hunting and collecting was ranked as a low threat that may not have substantial population-level impacts (albeit unknown how many are being trapped). Agricultural effluents (pesticides) were identified as the second highest threat after annual and perennial non-timber crops in COSEWIC (2022).
The BTOW publication, though dated 2020, hasn’t been updated since 2015. These more recent publications may help to better frame the important threats to the species. Incidental mortality from more frequent and earlier haying should be noted.
Grasslands National Park has in-person and/or ARU point count data on BOBO. Please contact the Ecological Integrity Monitoring or Wildlife Ecologists for the data.
Also, regarding the 2022 publication reference provided by Kathy St. Laurent above, note sections related to “Historical influence of human activity” and “Breeding Ground Habitat – General Description”. These sections provide some historical context for current population declines, particularly in the eastern portion of the range.
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. Bobolink is recommended to be listed as Near Threatened, approaching thresholds under Criteria A2bcd+4bcd.
We would like to thank contributors for the additional information provided in the above comments. Information on threats is especially helpful and will be incorporated into the updated species factsheet.
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.