Among the largest winged animals are those that belong to the Cathartidae family, the so-called American vultures, and among them, two species stand out: the Andean condor ( Vultur gryphus ) and the Californian condor ( Gymnopyps californianus ). Apart from these two species, another five complete the group, colloquially called ‘vultures’ or ‘auras’. Both species of condors compete in wingspan, sometimes exceeding three meters, and among all the birds they are only surpassed by some specimens of albatrosses.
The complex classification of condors
Traditionally, these seven species, the cathartis, have been classified within the great group of the Falconiformes , which bear the name of falcons, and to which the Old World vultures also belonged, belonging to the Accipitridae family together with the eagles.
However, new genetic-based classifications have broken these animals into three separate groups. In the group of falconiformes, today only the Falconidae remain —falcons, kestrels and the like—. The eagles and the vultures of the Old World form a group of their own, the Accipitriformes , separated from the previous ones. And which group the New World vultures belong to is still under discussion.
Some investigations frame the group within the Ciconiformes group —which includes the storks—. Other researchers propose to create a new group, the Cathartiformes . The strongest conclusions so far seem to indicate that the Accipitridae (including eagles, secretary, and Old World vultures) and New World vultures descend from a common ancestor, which lived in the late Cretaceous, millions of years after they split. of the falcons, which would effectively form an independent group.
Vultur gryphus , the Andean condor
The condor of the Andes , as its good name indicates, extends through practically the entire Andean mountain range, up to certain areas that exceed 5000 meters of altitude. It can be seen from the south of Argentina, passing through all of Chile, Bolivia and Peru, and with some populations in Ecuador and Colombia. In Paraguay and in the extreme west of Brazil it can be seen, but usually in passing. In Venezuela there are some populations from reintroductions.
It is estimated that the number of adult specimens does not exceed 7,000, and in a process of decrease, which has led the International Union for Conservation of Nature (IUCN) to classify the species in the category of “ vulnerable ”.
Gymnopyps californianus , the California condor
The California condor , although it also lives in mountainous regions, does not live above 2000 meters of altitude. Currently there are only three populations: one in the extreme south of the Sierra Nevada —the mountain range that separates the states of California and Nevada—, another between the states of Arizona and Utah, and a third in the state of Baja California (Mexico). The last two, in fact, come entirely from reintroductions from animals bred in captivity, which were naturalized.
At this time there are a total of 201 adult specimens in nature, of which 93 have successfully reproduced in the wild. Thanks to captive breeding and reintroduction programs, the population is increasing, although this is only due to the constant release of individuals . At the moment, the mortality in the populations is greater than their natural capacity to reproduce in the wild, which is why today the populations are totally dependent on conservation and reintroduction programs. For all these reasons, the IUCN lists the California condor as a “critically endangered” species .
The main threats of the condors
Condors are animals adapted to low reproductive and mortality rates, making them particularly vulnerable to disturbance .
In some regions, condors have a very bad reputation due to the belief that they attack livestock and are victims of attacks by people. Although it is known that, as with wolves and other wildlife, these attacks are actually anecdotal – in areas where condors live, they represent less than 1% of livestock losses. On the other hand, the presence of poisoned baits , normally directed at big cats, wolves and foxes, but which are also found and consumed by condors.
Another serious problem they face is lead poisoning . It affects both species, but the damage to the Californian condor has been devastating. Lead is a bioaccumulative contaminant that is transmitted through the food web; By feeding on carrion, condors and other vultures are the last link in the chain, receiving lead from all the other links. In addition, due to their feeding habits, they frequently feed on the remains of animals that have been killed by hunters, and consume the pellets and ammunition remains; more lead.
Other threats, of lesser magnitude, but significant, are given by the loss of habitat , especially in areas with agricultural function, when entering competition with feral dogs —abandoned and feral dog populations—, or by collisions against infrastructures such as poles and high voltage cables, wind turbines or telecommunications antennas.
The California condor suffers from an additional risk: West Nile virus . Currently, all animals that are released from captive breeding are vaccinated against this disease, so for the time being it is contained, but if the goal of reproduction in the wild exceeding mortality is reached, these animals will not be vaccinated, and herd immunity will be lost. In this scenario, West Nile fever may become an epidemic problem for the California condor.
References:
Adawaren, E. O. et al. 2020. The complete mitochondrial genome of Gyps coprotheres (Aves, Accipitridae, Accipitriformes): phylogenetic analysis of mitogenome among raptors. PeerJ, 8, e10034. DOI: 10.7717/peerj.10034
IUCN. 2022. The IUCN Red List of Threatened Species. Version 2021-3.
Johnson, J. A. et al. 2016. Multi-locus phylogenetic inference among New World Vultures (Aves: Cathartidae). Molecular Phylogenetics and Evolution, 105, 193-199. DOI: 10.1016/j.ympev.2016.08.025
