5 May 2025
Reproductive success of the Montagu's harrier increased by almost 180% in the north of Portugal in 2024
Male Montagu's harrier. Photo: Filippo Guidantoni/Palombar.
The reproductive success of the Montagu's harrier (Circus pygargus), a species at risk of extinction in Portugal, increased significantly in the north of the country in 2024, almost 180% higher than the projected scenario without protection interventions in the field. This reproductive success was due to the "Save the Montagu's harrier" campaign implemented by the environmental non-governmental organisation Palombar in that region, now part of the Iberian LIFE SOS Pygargus project. Thanks to the tireless work of the organisation's technicians, local farmers, collaborating entities and volunteers, a total of 53 new juveniles took flight in the district of Bragança that year, giving hope for the recovery of the species' populations in Portugal. In 2025, the campaign has already started to continue protecting this iconic bird of the fields, whose population has declined by 80% in ten years.
A critical year with decisive interventions
In 2024, 31 pairs were identified in the north of the country, with 29 nests being monitored continuously throughout the breeding season, according to data from the 2024 "Save the Montagu's harrier" campaign report, prepared by Palombar. Of these, only 27 pairs began laying eggs, and only three of these pairs laid a second clutch. In terms of clutch size, it was a year with higher average values compared to previous years: 4.8 eggs in the first clutches and 4.0 in the second.
The conservation measures implemented in the field by Palombar, in collaboration with the Wildlife Recovery Centre of the Veterinary Hospital of the University of Trás-os-Montes and Alto Douro (CRAS-HVUTAD), the Institute for Nature Conservation and Forests (ICNF), BIOPOLIS-CIBIO and volunteers, have been highly successful in increasing the reproductive success of this species. In their natural habitat, successful reproduction, i.e. when the reproductive effort results in at least one flying juvenile, occurred in about 40% of the nests monitored, including those that were protected by fences constructed by Palombar technicians. First, seven high-risk nests were protected with fences, four of which still had eggs and the other three already had chicks.
Of the fenced nests in the incubation phase, two were abandoned during harvesting, so our field technicians had to rescue the eggs and take them to CRAS-HVUTAD, where they completed their development. In total, 28 Montagu's harrier eggs were rescued during the 2024 breeding season, all in agricultural plots with imminent harvesting or abandoned by their parents during harvesting.
The rescued eggs resulted in 20 chicks which, after reaching about 19 days of age, were transported to the acclimatisation station (also known as “hacking cage”), where they remained for about a month. At the end of July, the 20 fledglings, aged around 50 to 55 days, were gradually returned to the wild (a method also known as soft release), used to facilitate the birds' attachment to the territory.
Without intervention in the field, the expected natural productivity in 2024 corresponded to a total of 19 fledglings, an insufficient number to ensure the viability of the Montagu's harrier population in northern Portugal. With the conservation actions described above, there was a significant increase in productivity, almost 180% higher than the projected scenario without intervention in the field. Thus, thanks to the campaign, in 2024, northern Portugal saw 53 new juveniles take flight.
In the 2024 campaign, ten juveniles and two adults were also tagged with GPS devices, in collaboration with the biologist Carlos Pacheco, from BIOPOLIS-CIBIO, who tagged the individuals, and the ICNF, which provided the GPS devices for the juveniles. The information provided by this equipment will be essential for improving measures to protect the species.
With each flight, each year, new lessons and the same challenges
Despite the success of the 2024 campaign, challenges remain that we must respond to effectively, in order to prevent the disappearance of the Montagu's harrier from Portugal, its historical territory.
The destruction of nests on cultivated or apparently abandoned and uncultivated land, mostly unintentionally and/or due to ignorance of their ecological value, or due to predation by other species, such as wild boar and foxes, remains a real threat. In these cases, the difficulty in identifying the owners hinders any attempt at timely protection and collaboration.
In addition, the financial compensation available to farmers, currently set at €250 per hectare in the Government's agri-environmental support for the protection of this species, is insufficient, especially in Trás-os-Montes, where many plots are small and conservation efforts can lead to significant losses of income.
To ensure the involvement of farmers, who are key players in the protection of the Montagu's harrier, it will be necessary to strengthen incentives, making them truly rewarding and adjusted to local realities.
But the sky is not empty, and hope continues to take flight...
In 2025, the LIFE SOS Pygargus project aims to strengthen and expand the conservation measures already implemented as part of the campaign, focusing on the protection of nests on cultivated and uncultivated land, the optimisation of threat mitigation measures and the GPS monitoring of juveniles returned to the wild, in order to assess the true scope and impact of interventions in the long term. It also aims to work to ensure better conditions for the involvement and active participation of farmers, through fairer and more effective incentives that recognise their essential role in the preservation of this species.
Among the many signs of hope that spring from the collective effort to prevent the imminent extinction of this bird, the story of the female P57 stands out. Returned to the wild in 2022 after being rescued from an endangered nest, she successfully reproduced in Spain and, in 2024, gave birth to a fledgling that has already been observed outside the nest, flying freely and being fed by its parent.
This is just one of many testimonies to the power of the dedication of all those involved in the campaign and the work carried out, which will enable the conservation of the Iberian Peninsula's fields and their iconic biodiversity.
The "Save the Montagu's harrier" campaign was launched in 2022 as part of the "Fields with Biodiversity: Let's Save the Montagu's harrier" project, developed by Palombar, BIOPOLIS-CIBIO, the National Association of Protein Crop Producers (ANPOC) and the Continente Producers' Club. It has now been integrated into LIFE SOS Pygargus. In 2024, it received financial support from the Belmiro de Azevedo Foundation.
About the project
LIFE SOS Pygargus - Urgent conservation actions to sustain Portuguese and transborder populations of the Montagu’s harrier is an Iberian project that brings together conservationists, farmers, scientists and public and private entities in an unprecedented effort to save this migratory bird from imminent extinction in some of its main areas of distribution in the Iberian Peninsula.
It combines nature conservation and agriculture to protect this species, which is fundamental to the balance of ecosystems. It is 75% funded by the European Union's LIFE programme and co-funded by Viridia – Conservation in Action, Lightsource bp and the Environmental Fund.
It is implemented by a consortium comprising Palombar – Conservação da Natureza e do Património Rural (coordinating entity), BIOPOLIS-CIBIO Association, AEPGA - Associação para o Estudo e Proteção do Gado Asinino, ANPOC - Associação Nacional de Produtores de Proteaginosas, Oleaginosas e Cereais, CCDR-N - Comissão de Coordenação e Desenvolvimento Regional do Norte, EDIA - Empresa de Desenvolvimento e Infraestruturas do Alqueva SA, ICNF - Instituto da Conservação da Natureza e das Florestas, INIAV - Instituto Nacional de Investigação Agrária e Veterinária, LPN - Liga para a Protecção da Natureza, MC Shared Services SA, Modelo Continente Hipermercados SA, SPEA - Sociedade Portuguesa para o Estudo das Aves, UTAD - Universidade de Trás-os-Montes e Alto Douro, Vita Nativa - Conservação do Ambiente, AMUS - Acción por el Mundo Salvaje, Consejeria de Agricultura, Ganaderia y Desarrollo Sostenible - Junta de Extremadura, GREFA - Grupo de Rehabilitación de la Fauna Autóctona y su Hábitat and the University of Murcia.
Monitoring. Photo: Palombar.
A critical year with decisive interventions
In 2024, 31 pairs were identified in the north of the country, with 29 nests being monitored continuously throughout the breeding season, according to data from the 2024 "Save the Montagu's harrier" campaign report, prepared by Palombar. Of these, only 27 pairs began laying eggs, and only three of these pairs laid a second clutch. In terms of clutch size, it was a year with higher average values compared to previous years: 4.8 eggs in the first clutches and 4.0 in the second.
The conservation measures implemented in the field by Palombar, in collaboration with the Wildlife Recovery Centre of the Veterinary Hospital of the University of Trás-os-Montes and Alto Douro (CRAS-HVUTAD), the Institute for Nature Conservation and Forests (ICNF), BIOPOLIS-CIBIO and volunteers, have been highly successful in increasing the reproductive success of this species. In their natural habitat, successful reproduction, i.e. when the reproductive effort results in at least one flying juvenile, occurred in about 40% of the nests monitored, including those that were protected by fences constructed by Palombar technicians. First, seven high-risk nests were protected with fences, four of which still had eggs and the other three already had chicks.
Nest with eggs. Photo: Filippo Guidantoni/Palombar.
Nest protected with fences after harvesting. Photo: Filippo Guidantoni/Palombar.
Of the fenced nests in the incubation phase, two were abandoned during harvesting, so our field technicians had to rescue the eggs and take them to CRAS-HVUTAD, where they completed their development. In total, 28 Montagu's harrier eggs were rescued during the 2024 breeding season, all in agricultural plots with imminent harvesting or abandoned by their parents during harvesting.
The rescued eggs resulted in 20 chicks which, after reaching about 19 days of age, were transported to the acclimatisation station (also known as “hacking cage”), where they remained for about a month. At the end of July, the 20 fledglings, aged around 50 to 55 days, were gradually returned to the wild (a method also known as soft release), used to facilitate the birds' attachment to the territory.
Rescued chicks. Photo: Palombar.
Chick at the acclimatisation station (or hacking cage). Photo: Pedro Alves/Palombar.
Without intervention in the field, the expected natural productivity in 2024 corresponded to a total of 19 fledglings, an insufficient number to ensure the viability of the Montagu's harrier population in northern Portugal. With the conservation actions described above, there was a significant increase in productivity, almost 180% higher than the projected scenario without intervention in the field. Thus, thanks to the campaign, in 2024, northern Portugal saw 53 new juveniles take flight.
In the 2024 campaign, ten juveniles and two adults were also tagged with GPS devices, in collaboration with the biologist Carlos Pacheco, from BIOPOLIS-CIBIO, who tagged the individuals, and the ICNF, which provided the GPS devices for the juveniles. The information provided by this equipment will be essential for improving measures to protect the species.
Flying juvenile with GPS equipment ready to be returned to the wild. Photo: Palombar.
With each flight, each year, new lessons and the same challenges
Despite the success of the 2024 campaign, challenges remain that we must respond to effectively, in order to prevent the disappearance of the Montagu's harrier from Portugal, its historical territory.
The destruction of nests on cultivated or apparently abandoned and uncultivated land, mostly unintentionally and/or due to ignorance of their ecological value, or due to predation by other species, such as wild boar and foxes, remains a real threat. In these cases, the difficulty in identifying the owners hinders any attempt at timely protection and collaboration.
In addition, the financial compensation available to farmers, currently set at €250 per hectare in the Government's agri-environmental support for the protection of this species, is insufficient, especially in Trás-os-Montes, where many plots are small and conservation efforts can lead to significant losses of income.
To ensure the involvement of farmers, who are key players in the protection of the Montagu's harrier, it will be necessary to strengthen incentives, making them truly rewarding and adjusted to local realities.
Nest protected with fences. Photo: Filippo Guidantoni/Palombar.
A collaborative effort with farmers. Photo: Palombar.
But the sky is not empty, and hope continues to take flight...
In 2025, the LIFE SOS Pygargus project aims to strengthen and expand the conservation measures already implemented as part of the campaign, focusing on the protection of nests on cultivated and uncultivated land, the optimisation of threat mitigation measures and the GPS monitoring of juveniles returned to the wild, in order to assess the true scope and impact of interventions in the long term. It also aims to work to ensure better conditions for the involvement and active participation of farmers, through fairer and more effective incentives that recognise their essential role in the preservation of this species.
Ringed harrier. Photo: Palombar.
Among the many signs of hope that spring from the collective effort to prevent the imminent extinction of this bird, the story of the female P57 stands out. Returned to the wild in 2022 after being rescued from an endangered nest, she successfully reproduced in Spain and, in 2024, gave birth to a fledgling that has already been observed outside the nest, flying freely and being fed by its parent.
This is just one of many testimonies to the power of the dedication of all those involved in the campaign and the work carried out, which will enable the conservation of the Iberian Peninsula's fields and their iconic biodiversity.
Male Montagu's harrier. Photo: Filippo Guidantoni/Palombar.
The "Save the Montagu's harrier" campaign was launched in 2022 as part of the "Fields with Biodiversity: Let's Save the Montagu's harrier" project, developed by Palombar, BIOPOLIS-CIBIO, the National Association of Protein Crop Producers (ANPOC) and the Continente Producers' Club. It has now been integrated into LIFE SOS Pygargus. In 2024, it received financial support from the Belmiro de Azevedo Foundation.
About the project
LIFE SOS Pygargus - Urgent conservation actions to sustain Portuguese and transborder populations of the Montagu’s harrier is an Iberian project that brings together conservationists, farmers, scientists and public and private entities in an unprecedented effort to save this migratory bird from imminent extinction in some of its main areas of distribution in the Iberian Peninsula.
It combines nature conservation and agriculture to protect this species, which is fundamental to the balance of ecosystems. It is 75% funded by the European Union's LIFE programme and co-funded by Viridia – Conservation in Action, Lightsource bp and the Environmental Fund.
It is implemented by a consortium comprising Palombar – Conservação da Natureza e do Património Rural (coordinating entity), BIOPOLIS-CIBIO Association, AEPGA - Associação para o Estudo e Proteção do Gado Asinino, ANPOC - Associação Nacional de Produtores de Proteaginosas, Oleaginosas e Cereais, CCDR-N - Comissão de Coordenação e Desenvolvimento Regional do Norte, EDIA - Empresa de Desenvolvimento e Infraestruturas do Alqueva SA, ICNF - Instituto da Conservação da Natureza e das Florestas, INIAV - Instituto Nacional de Investigação Agrária e Veterinária, LPN - Liga para a Protecção da Natureza, MC Shared Services SA, Modelo Continente Hipermercados SA, SPEA - Sociedade Portuguesa para o Estudo das Aves, UTAD - Universidade de Trás-os-Montes e Alto Douro, Vita Nativa - Conservação do Ambiente, AMUS - Acción por el Mundo Salvaje, Consejeria de Agricultura, Ganaderia y Desarrollo Sostenible - Junta de Extremadura, GREFA - Grupo de Rehabilitación de la Fauna Autóctona y su Hábitat and the University of Murcia.