Throughout history, ever since humans learned to travel from one continent to another we see nothing BUT ‘invasive species’ practically everywhere we look. Every animal can be considered as non-native, alien or invasive at some point, (introduced by humans accidentally or intentionally). Therefore the term “Invasive species means almost nothing anymore. Sure, SOME of them may do serious damage (eg. Cane Toads in Australia which became pests after having being introduced into Australia to control destructive beetles in Queensland’s sugarcane crops), or the Mosquitofish introduced in Spain to control mosquitos (Malaria) in the 1920’s. However, the majority of other cases are almost always over hyped, as they are with these two parrot species, particularly in the case of Myiopsitta monachus.
The major take home point here is that it is essentially IMPOSSIBLE to eradicate a species once it has been introduced into a new area. Controlling invasive species often involves problematic choices, there have been very few successes (Alaska's Hawadax Island and its mass poisoning of rats in 2008); and come at great cost, both in terms of currency and costs to wildlife. This operation cost US $2.5-million and probably caused the poisoning of 46 bald eagles and 320 gulls scientists found dead on the island afterwards. Engaging in a high cost eradication is one thing, but then comes the prolonged and continuous efforts to ensure that the undesired species does not make its way back again. We should recognize and learn from past errors that controlling or eradicating a certain species can lead to imbalance through propagation of other species that in turn may lead to a host of other unforeseen, more undesirable outcomes. And although you will hear the politicians talk about "control", you cannot really control new species effectively once they are introduced into your area. (Well, certainly not easily, cheaply or without causing many other consequences as well).This mentality of trying to eradicate species "that never used to be here before" is an exercise in futility because the whole world is connected now. This means that various species are being spread everywhere, and if the climactic and weather conditions in their new location are not ultimately terminal then that species will now exist there from this point forward. Trying to change that reality is a loser’s game.
To further complicate the matter, at what point does an introduced species become classified as an Invasive Species? If they spread beyond the place of introduction and compete for resources with native species? Case in point: Misconception and mismanagement of an invasive species : “The paradoxical case of an alien ungulate in Spain” by Jorge Cassinello. First published February 2018 https://doi.org/10.1111/conl.12440
Back to the parrots in Seville, while it is said that they do not have predators, they are indeed vulnerable to their own share of attacks from all sorts of predators (hawks, owls, dogs, cats, snakes, rats and humans). In fact, specifically in Europe, some predators include the Eurasian Sparrowhawk, the Booted eagle, the Black kite, the Jackdaw, the Lesser kestrel and Black rats.These parrots are both non-migratory, primarily sedentary birds and it is the conditions of the areas into which THEY WERE RELEASED that have proven favourable, and allowed them to grow in numbers. As preyed upon creatures they too are part of a food chain that may cause other imbalances if they are removed from their naturalized environments.
Specifics on the exact numbers of parrots which are to be ‘controlled’ (meaning killed here) is hard to find, however I did read that it involves some 1500 Argentina parrots ( Myiopsitta monachus), and 4000 Kramer parrots ( Psittacula krameri). The main reasons cited are competition to the Greater noctule and to the Lesser kestrel. With reference to Myiopsitta monachus none of these reasons are valid, not in terms of food competition nor aggression nor nesting competition for existing tree cavity nests. The Monk parakeet is well-known for being the only parrot that does not nest in cavities. There may be a valid concern that Psittacula krameri could cause loss of suitable cavities for the Noctule bat, but at this point the research is minimal and actual proof is scant at best. However, equally of concern should be the number of feral pigeons and house sparrows that are also known to occupy a great number of nests out of the list of 10 species of birds and bat that compete for mature tree cavities. The raucous anti-predatory nature of Psittacula krameri could be of benefit to other nesting birds when it comes to predators such as the black rat and the squirrel, who also raid nests for eggs.
There are no woodpeckers in the Maria Luisa park (Interestingly enough they are elsewhere in Seville, perhaps they are avoiding predators?) to create new cavities, therefore all available nest cavities stem from aging tree rot and decay. As the land surrounding Seville is heavily deforested and mainly confined to agriculture, this park is a haven for many species. Adding to the short supply of natural tree cavities, decaying tree limbs are pruned in the interests of public safety, and this is unfortunately done in the summer when the presence of all birds and bats is at its peak, and logically, this does not help the situation. The Greater noctule and the Lesser kestrel both travel to forage and migrate several times a year. The one research paper that I have seen as being the basis of all reporting by the media points to the Psittacula krameri as having a deleterious effect on the bat and makes no mention of Myiopsitta monachus as negatively effecting the presence of the bat. This study by its own admission, states that there are no published information on population size for this bat, and ‘relies on temporal changes in the number of trees used by the this bat species as a surrogate of changes in population size.’ So in other words, If fewer nests are used by bats, and more nests are used by Psittacula krameri and the other 8 tree cavity bird dwellers in the park, it must be deduced that Psittacula krameri is responsible for the number of bats not returning to this site, based on the diminished number of nests the bats occupy? How and why does one go from this one assumption to statements made by the media that these parrots have DECIMATED the bat population or that they are DEMONS?
The bats have large foraging ranges, usually moving 15–40 km from the park in a single night to hunt for insects and migrating songbirds, and rely on marshland fields where they look for insects at night and wait for nocturnally migrating song-birds to capture in flight (on-the-wing). These changes in habitat based on their foraging needs suggest that they are heavily dependent upon areas that can support their food supply regardless of how far they must travel to get to their prey. Anything can happen to them along their journeys.
This is a recent article regarding the Guadaira river, surely events such as this will have serious deleterious impact on all wildlife in the region, particularly those that feed on birds, insects or fish. Will Psittacula krameri or even Myiopsitta monachus be further blamed as these types of occurrences take a toll on the Nyctalus lasiopterus and the Falco neumani?
”They denounce the death of "thousands" of fish on the stretch of the Guadaíra river closest to the Guadalquivir’,10/09/2019
“Activists of Ecologists in Action have denounced before the Civil Protection Service (Seprona) of the Civil Guard an episode of fish mortality in the Guadaíra river, where "thousands" of specimens had died for reasons not yet clarified but that the collective connects with a possible industrial spill.
José Luis Anguita, a member of Ecologists in Action, explained to Europa Press that he himself checked around 4 pm on Monday when he played sports along the banks of the Guadaíra river that "thousands of fish" floated on the sheet of water dead. Recognizing that the Guadaíra has already been the scene of episodes of fish mortality, this activist has warned that personally, he "had never seen anything like this", in relation to the number of fish carcasses.”
In 1998, a major ecological disaster happened in Andalucia, Five million cubic metres of acidic waste water--poured into the surrounding area adjoining the Donana Park( one of Europe’s most important wetland reserves and a major site for migrating birds). https://www.wsws.org/en/articles/1998/05/span-m13.html
Then there is the consideration of wind turbines and the damage they unleash on bird and bat populations. According to this article published in 2016. “In Spain, the proliferation of wind farms has been chaotic, and based on location, some of these wind turbines are even known as “killers”, and depending on their locations, some mills have been said to cause the death of 80% of birds in the area. In fact, in the Guidelines for the evaluation of the impact of wind farms on birds and bats by SEO Birdlife stated that the number of birds and bats killed by these wind turbines ranges between 6-18 million.”
https://www.lavanguardia.com/natural/20160729/403487721857/molino-eolico-evita-muerte-aves.html
https://www.carbonbrief.org/bird-death-and-wind-turbines-a-look-at-the-evidence
https://www.audubon.org/news/will-wind-turbines-ever-be-safe-birds
https://physicsworld.com/a/wind-turbine-impacts-deplored/
Pesticide use is also known to be a cause of decline in numbers of Greater noctule bats as well as Lesser kestrels, and it seems Spain ranks pretty high in it’s use of pesticides.
https://www.euronews.com/2018/10/15/which-eu-countries-consume-the-most-pesticides
https://www.sciencedirect.com/science/article/pii/S0048969718343420
“Estimations of the abundance of the Lesser kestrel show that breeding numbers have dropped by 95% since the 1950's. Sharp declines are especially obvious in its European range.” https://animaldiversity.org/accounts/Falco_naumanni/ These parrots were not even in Spain until the mid 70’s, and were first noticed in the Maria Luisa Park in the mid to late 90’s…
So you see when it comes to assigning blame, one has to be prepared to look further than what is directly under one’s nose. Especially when it comes to killing such highly intelligent, and emotional creatures with complex, social lives such as these wonderful parrots, their lives should not be considered so easily dispensable.
Any society that would do such a despicable wholesale slaughter of innocent parrots should be highly ashamed of itself! This makes the rest of the world view Spain as a murderous and barbaric country, and I know the people of Spain are not guilty of this! This is NOT acceptable! Please KEEP sharing, we cannot do this without YOU! Thank you.