Distribution and migration phenology of Purple Martins (Progne subis) in Brazil

Abstract

Purple Martins (Progne subis) are Neotropical migratory birds that breed across North America and spend their nonbreeding season in South America, primarily Brazil. They have been in a long-term population decline over the last five decades. There are several suggested causes for the decline, but to begin understanding the conservation needs of this species, it is necessary first to fill existing knowledge gaps about migration timing, distribution, and habitat use in Brazil. The presence of this species across most of Brazil makes it difficult to keep track of seasonal or long-term changes in its distribution without careful, widespread data collection. Citizen science offers an emerging opportunity to address knowledge gaps of roost distribution and phenology. Here, we compiled Purple Martin records from citizen science platforms, scientific collections, and bibliography to produce an overview of the distribution and phenology of the species in Brazil. It is present in most Brazilian states, but records are concentrated in the Amazon region. Previously known large roosts in southeast Brazil, especially in the state of São Paulo, have decreased in number of individuals over the last decade. Most records are from September to April, although phenology varies with latitude. In the equatorial region (5°N-5°S), which is crossed by all populations that come to Brazil, the number of reports shows strong temporal variation, probably related to the timing of migration in different populations.

Central-place foraging poses variable constraints year-round in a neotropical migrant

“…Given that aerial insectivores are a rapidly declining avian guild [ 21 – 23 ], and there is no consensus on the main cause of decline [ 9 , 24 , 25 ], understanding their year-round habitat requirements is critical for developing management practices that would contribute to conservation [ 26 , 27 ]. Purple martins breed in North America and winter in South America, where individuals from different breeding sites mix in enormous roosts, some containing over 10,000 birds [ 20 , 28 – 31 ]. Similar to other aerial insectivores, purple martins have declined by 30% in North America over the last 5 decades [ 32 ].…”

Concentração de centenas de milhares de indivíduos de andorinha-do-campo Progne tapera (Aves: Hirundinidae) em ambiente urbano do interior paranaense

“…Já foram mencionados milhares de indivíduos em áreas antropizadas para o Amazonas (Doughty & Fergus, 2002;Stotz et al, 1992), Mato Grosso (Antas et al, 1986Tubelis & Tomas, 2003), no vale do Araguaia, entre Tocantins e Pará (Olmos & Pacheco, 2008), e no Parque Estadual do Cantão, Tocantins (Dornas & Pinheiro, 2007), ambientes naturais nas duas últimas localidades. Recentemente, registros provenientes de espécimes de museus, revisão bibliográfica e plataformas de ciência cidadã indicaram a presença de P. subis (Linnaeus, 1758) em 24 estados brasileiros (bandos ou poucos indivíduos), especialmente na Amazônia (Santos et al, 2021).…”

“…Percebeu-se o aumento na abundância das aves na década de 1970, mas tais concentrações demonstraram redução no número de indivíduos na última década (Santos et al, 2021), ou até mesmo desapareceram por completo, em algumas localidades cerca de duas décadas depois (Willis & Oniki, 2002). Embora variações climáticas recentes possam ter causado o desvio das rotas das espécies por falta de micro-habitats para elas ade-quado (Projeto Andorinha Azul, 2020), é fato que moradores locais se sentiram importunados com as grandes quantidades de fezes acumuladas pelas aves.…”

New record of the chewing louse Myrsidea dissimilis (Kellogg, 1896) (Phthiraptera: Menoponidae) parasitizing a Purple Martin, Progne subis (Linnaeus, 1758) (Passeriformes: Hirundinidae) in Amazonas, Brazil

“…The roost comprises individuals belonging to the subspecies Progne subis subis (L., 1812) (Passeriformes: Hirundinidae), known to breed in the eastern coast of the United States. In the Comaru island, thousands of Purple Martins share the roost with other resident and migratory species of Hirundinidae, such as Progne tapera (L., 1766), P. chalybea, and Hirundo rustica Linnaeus, 1758, every year, from January to April (Santos et al 2021). This study was approved by the SISBIO (n° 73608) and is titled "Andorinha Azul (Purple Martin)".…”

“…These three species of swallows have different phenology and distributions. Purple Martins, P. subis, are Neotropical migrants that breed exclusively in the Northern Hemisphere and migrate long distances to Brazil (Allen & Nice 1952;Santos et al 2021). Grey-breasted Martin, P. chalybea, occurs from Mexico to central Argentina and are resident throughout most of its distribution (Howell & Webb 1995), and the southern populations migrate to Amazon during the Austral winter (Eisenmann & Haverschmidt 1970;Sick 1993).…”