The second simultaneous census of Andean condor conducted in San Luis brought good news for the conservation of this threatened species.
The report was prepared by the Secretariat of Environment and Sustainable Development of the province together with the Bioandina Argentina Foundation, showing the highest number of specimens ever recorded in Argentina.
During the survey, 80 individuals were observed simultaneously thanks to the work of dozens of census takers.
These censuses are essential to understand the state of the species and continue studying its population dynamics in search of better conservation strategies.
How the Andean condor census was conducted in San Luis
The Andean condor census was carried out on September 6, 2025, in the form of a “simultaneous survey”.
This method is essential to avoid registering the same specimen more than once.
Since condors can fly 350 km in a single day, at speeds of up to 240 km/h and action areas of more than 200,000 km2, this complicates traditional field counts.
“Thus, the most accepted and currently used method is simultaneous counts,” states the report from the province of San Luis.
This is key because “it avoids counting an individual more than once per sampling point.”
Therefore, “it requires many trained observers and the appropriate logistics to reach each of the observation posts.”
Thus, after extensive preparation, the II Andean condor census in San Luis was conducted from 8:00 to 14:30 hours.
The sighting took place at 19 strategic posts distributed in the Sierras de San Luis and Comechingones.
71 census takers participated, monitoring both communal roosts and flight areas of this threatened species.
Thanks to this logistics, “the maximum number of condors recorded simultaneously at all observation posts was 80 individuals.”
These “were observed in the interval from 11:00 to 11:05 am,” the report indicates.
The survey is a milestone in its class as it surpassed all previous censuses conducted in the country, including Mendoza, Neuquén, and Jujuy.
Of the 19 observation points, 12 corresponded to flight areas and 7 to roosts.
The most significant records were obtained at the Saladillo roost (28 individuals) and the flight area in the Higueritas Provincial Reserve (27 individuals).
New Andean condor census in San Luis: population composition
The analysis of the observations allowed the identification of 73 distinct specimens by age category: 50 adults, 11 subadults, and 12 juveniles.
This proportion of 68% adults and 32% immatures aligns with what is expected according to previous population studies in Argentina and Chile.
The document notes that “these proportions align with what is expected in nature according to the literature.”
The results thus indicate a healthy population structure in the central Argentine sierras.
The Andean condor (Vultur gryphus) is the largest scavenger bird in the world and is categorized as vulnerable globally by the International Union for Conservation of Nature (IUCN).
In Argentina, pesticide poisoning and lead intoxication are its main threats.
The plan to census Andean condors in the country
This survey is part of the Comprehensive Conservation Plan for the Andean Condor (PCCA), which has more than 30 years of continuity.
The network of Condor Sanctuaries for Nature Conservation covers more than 76,759 km² in 11 Argentine provinces.
The San Luis census marks a significant milestone, as “until now, the highest record was obtained in the 18th census of Mendoza.”
There, the maximum observed was 70 condors simultaneously, while this time 10 more specimens were recorded.
Favorable weather conditions during the day —clear skies, no rain or fog— contributed to the success of the survey.
Only the Desaguadero point did not record individuals, while several sites that had not observed condors in the previous census did so this time.
Now, the collected data will be used to develop spatial ecological suitability models and make population estimates through the construction of specific statistical models for the species.
The continuity of these censuses will allow for the evaluation of the population dynamics of the Andean condor and the design of conservation strategies based on reliable information.
