Loros barranqueros

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Alan Omar Bermúdez Cavero

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Oct 15, 2021, 10:31:25 AM10/15/21
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https://www.diariodesevilla.es/sevilla/estudio-loros-barranqueros-monte-andino_0_1617140062.html?utm_source=whatsapp.com&utm_medium=socialshare&utm_campaign=mobile_web

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Dr. Alan Omar Bermúdez Cavero
Lab. Biología y Genética
Univ. Nac. de San Cristóbal de Huamanga
Telf. +51 943825461
Perú

Juan F. Masello

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Oct 20, 2021, 5:41:51 PM10/20/21
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Thank you Alan for sharing! I imagine that the article is related to this paper:
 
Blanco G, Romero-Vidal P, Carrete M, Chamorro D, Bravo C, Hiraldo F, Tella JL 2021. Burrowing Parrots Cyanoliseus patagonus as Long-Distance Seed Dispersers of Keystone Algarrobos, Genus Prosopis, in the Monte Desert. Diversity 13: 204. https://doi.org/10.3390/d13050204
 
 
This paper make a nice contribution to our understanding of the different roles of Burrowing Parrots in the different ecosystems they occupy. And, it gives nice insights on the poorly known diet of the species. A great contribution in that sense.

However, I think, there is a problem with the parrot abundance presented. Cyanoliseus patagonus andinus has NOT a high abundance, as mentioned in e.g. the abstract. In our paper in

https://frontiersinzoology.biomedcentral.com/articles/10.1186/1742-9994-8-16

we show that the total Cyanoliseus patagonus andinus population numbers no more than 2,000 nests (see Tables 1 and 2). According to other unpublished data a student of mine is working with at present, that number may be slightly larger now. But, still, I would not speak of "high abundance", when they only represent a 4% of the total population size of the species, and when only 65% of the colonies known in the past were found during our extensive survey (which means 35% of the colonies are gone). This could turn to be a dangerous message that can be used by some people trying to resume the capturing of Burrowing Parrots for the pet trade.

Of course, 2000 nests comparing with other Neotropical parrots specie is a lot. But, still, we need to see things here in the context of the Burrowing Parrots and not in the context of other threatened and less numerous species of the continent.

Where does this problem on abundance estimate come from? First, the distribution of Burrowing Parrots is far from homogeneous. They tend to concentrate close to water courses, where the colonies are usually built, and close (<50 km) to the remaining patches of Monte vegetation (see details in the paper linked above). So, in that way, presenting the results of the surveys in "parrots per km surveyed" may generate unwanted errors and inflate the numbers. And, I think, distance sampling is not the right method for Burrowing Parrots. What we did in the paper linked above was to visit all known colonies (and some we discovered; 15,000 km surveyed) and count all nests. It is easy to recognise those that are active from those that are not due to the faeces present at the entrances of the active ones but absent from the others.

The second problems I see is the assumption made with respect to the parrots detected aurally. In Blanco el al. (2021), the mean flock size of parrots detected visually was assigned to the aural records. This may sound logic but, in my view, it is not. Burrowing Parrots are extremely noisy and a small group may sound as a large one.

The third problem is that Burrowing Parrots are extremely mobile, flying up to 240 km per day. See

https://www.researchgate.net/publication/224463259_Population_size_provisioning_frequency_flock_size_and_foraging_range_at_the_largest_known_colony_of_Psittaciformes_The_Burrowing_Parrots_of_the_north-eastern_Patagonian_coastal_cliffs

In the 529 km surveyed by Blanco el al. (2021) the same Burrowing Parrot flocks could have been counted more than one time.

My intention is not to take away value from the main conclusions from Blanco el al. (2021) but to warn about one particular problem which may trigger unwanted "management" actions on the species.

Glad to discuss this further.

Cheers, JUAN


 
 
 
 
 
 
 
Dr. Juan F. Masello
Justus Liebig University Giessen

Personal information, projects and publications
http://www.uni-giessen.de/masello

Behavioural ecology
http://www.frontiersinzoology.com/content/8/1/16

Energy landscapes
https://movementecologyjournal.biomedcentral.com/articles/10.1186/s40462-021-00255-9

Evolution
https://academic.oup.com/mbe/article/36/8/1671/5480301

Loros barranqueros - Embajadores del Monte
https://lorosbarranqueros.blogspot.com/
 
 

Gesendet: Freitag, 15. Oktober 2021 um 16:31 Uhr
Von: "Alan Omar Bermúdez Cavero" <bec...@gmail.com>
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Betreff: {Parrot Researchers Group} Loros barranqueros
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