Every winter, Mexico´s Northwest experiences a large-scale natural phenomenon. We refer to the arrival of hundreds of thousands of birds from the north of the continent to spend the winter in the wetlands of the Baja California peninsula, Sonora, Sinaloa, and Nayarit. Shorebirds and waterfowl take advantage of the region’s temperate climate and find shelter and food here. This makes the wetlands of northwestern Mexico a strategic point for the survival of these species.
That is why this week, Pronatura Noroeste (PNO), together with the Bird Laboratory of the Autonomous University of Baja California Sur (UABCS), will begin a massive count of migratory birds in the region´s 15 most important wetlands. This migratory birds´s detailed population register is carried out with scientific observation methods, the use of land, water, and aerial vehicles, technological instruments, and qualified technical personnel from both institutions. The federal government also participates through the National Commission of Protected Areas.
Likewise, this environmental conservation procedure, which is implemented every two years, also serves to make known the state of the wetlands and the possible threats to the conservation of these birds habitat. It is worth mentioning that, according to the count of the last few years, a population decrease of 11% has been observed in the abundance of birds that use the so-called Pacific migratory corridor, which includes the entire west coast of the continent. Some migratory birds are threatened or even in danger of extinction, so monitoring their populations during the winter season in northwestern Mexico provides information of great ecological relevance.
This work led by Pronatura Noroeste and the UABCS is part of a continental effort in which multiple institutions coordinate to record and study the life cycle of migratory birds. In this context, Gustavo Danemann, Director of Pronatura Noroeste, explained the relevance of this work by stating that “monitoring wildlife, in this case, migratory birds, allows us to know the vital signs of their populations and the ecosystems that serve as their habitat.”
For more than two decades, the collaboration between these institutions has allowed sustained work to create extensive databases, essential in conservation efforts and compliance with laws in this area. Thanks to the results of this winter monitoring in the 2015-2020 period, it is known, for example, that the region’s wetlands are home to more than 1.6 million shorebirds of at least 31 species and that most of these birds are found in specific locations, such as the Huizache-Caimanero lagoon in Sinaloa, which concentrates 23. The Huizache-Caimanero lagoon in Sinaloa accounts for 23.2% of the total winter migrants, followed by the Guerrero Negro lagoon in Baja California Sur with 17% and Bahía Santa María in Sinaloa with 10.7% of the total number of birds recorded, respectively.
As can be seen, the biannual bird count by Pronatura Noroeste and the UABCS is a decisive action to guarantee the conservation of these species. Many of them concentrate a large part of their total world population in this migration and are highly sensitive to climate change, pollution, and urban expansion, so we must maintain this environmental conservation effort.
