There is barely a month left before the arrival of winter, and the observation of the birds that appear and settle in Spain at this time of year concludes that fewer and fewer come to Spain.
This is the conclusion that arises from the observation of volunteers who participate in the SEO/BirdLife Citizen Science Programvia the program called Sacin.
The tool is active to know the state of bird populations in winter, so we know that in Spain there have been approximately 19% fewer individuals in 2023 compared to 1998 at this time of year. The analysis of data collected on more than 80 bird species over 15 seasons allows us to reach this conclusion.
Global warming
The causes may be due to the fact that their wintering populations are decreasing in Spain, as is the case of match bunting or the bunting commonwhich we find in slope.
Other causes are also identified, such as those of other sedentary species such as the red partridgeor the European goldfinch. Furthermore, SEO/BirdLife points out that birds are stopping migrating from central and northern Europe to Mediterranean regions, due to climate change during winter season due to global warming .
The importance of studying birds
Long-term monitoring of populations of common and dispersed birds provides very valuable information on the evolution of their populationsand allows us to know how they are evolving.
It is a key indicator for establishing species that have conservation problems, in addition to identifying habitats where these populations have greater problems when declines are detected in the same.
On the other hand, the analysis of the information generated offers an excellent biological indicator of the climate change. The fact that birds no longer need to travel to southern Europe to avoid the continent’s cold winters is one of the best indicators of biodiversity-driven climate change.
Long-term monitoring
Furthermore, when this information is obtained from long-term monitoring of populations of wintering birds that arrive in Spain in greater or lesser numbers depending on the more or less harsh winters also serves as a thermometer on how biodiversity and ecological processes are affected by climate change.
In this sense, the information collected allows us to know the most recent evolution of the populations of these birds at this time of the yearand use this value as one of the criteria to be taken into account when establishing its state of conservation and, where applicable, its classification of threats according to the values established at the international level by the International Union for Conservation of Nature (IUCN) .
Winter Bird Data
As in the spring, with the results obtained with the Sacre program, in Sacin the species of agricultural means such as the European goldfinch and the greenfinch are those that show the most unfavorable trends in winter.
This may be due to the fact that intensification and transformations of the landthat have occurred in these environments in recent years have not been favorable to the majority of these species.
Between stability and decline
The results obtained during the last campaign since this monitoring was carried out show that, even if, many of the 20 most abundant species in winter are in a favorable situation Species, or at least stable ones, such as the blackbird, the European goldfinch and the greenfinch are said to be in decline, becoming less and less abundant at this time of year.
More in the short term, considering only the last 10 years, in the case of buntingcommon, the decline would be pronounced. Other species for which a reduction in their short-term wintering populations has been observed, in addition to the previous ones, would be the pipit pratenseTHE crow blackTHE western jackdaw he common linnetor the barred wren.
Declining populations
If we take into account the entire period, from 2008 to the present, declines are identified in the populations of the red partridge, common kestrel, common lark the mountain bunting and the common lark.
SEO/BirdLife publishes information each year on the many bird monitoring programs that it develops with the aim of disseminating knowledge in society.
Citizen science
To participate you need to know how to identify the most common birdsthat we usually see in the countryside, because it is necessary to note how many specimens of each of these species are observed.
It can be done in any frequently visited area and with very little travel effort so that annual census sampling can be carried out comfortably and over several years.
Field days
Sacin is executed during two days in the field bird watching in the depths of winter. The first day, between mid-December and mid-January; and the second, from mid-January to mid-February.
Each day,it is necessary to note all birds seen or heardduring a walk or a two-hour circuit previously established and repeated each year.