CathInfo.com

They are saying that with the coming of the Catholic Faith infanticide is being wiped out.

A bishop of a diocese in Brazil has said reports about infanticide being carried out by some indigenous peoples were “shocking,” but that he was unaware of any such practices continuing among the indigenous people who are part of his flock.
Speaking to reporters at the Vatican today during a break in the Synod of Bishops for the Pan-Amazon Region, Bishop Wilmar Santin of Itaituba, Brazil, acknowledged infanticide was a practice of the past, and that although he has not witnessed it in his diocese, was unable to say if it continues “for other peoples.”
The issue of infanticide has become a focus of discussions in the media after it emerged that the practice is continuing among possibly as many as 20 indigenous peoples in the Amazon.
Amazonian chief Jonas Marcolino Macuxí also told the Register and a Rome conference this month that infanticide is still practiced, and that it had been dying out until liberation theologians arrived in the region in the 1970s.
Peruvian Cardinal Pedro Ricardo Barreto Jimenez told reporters Tuesday he was unaware the practice was still occurring, and challenged the media to produce evidence.
Swiss Vatican journalist Giuseppe Rusconi then published four pieces of docuмented evidence (translated here in English by Italian Vaticanist Sandro Magister).

In his comments, Bishop Santin explained how serious the practice was among the Munduruku people of his diocese until religious sisters, many working as nurses, “slowly made sure the practices disappeared completely.” He said the Munduruku people are a “bellicose” people who, before the missionaries arrived, “cut off the heads” of enemies and “took them as trophies.”

Bishop Medardo de Jesús Henao Del Río, the apostolic vicar of Mitú, Colombia, told reporters that before missionaries arrived in his diocese in 1914, children with defects were “left to die, eaten by animals or ants.” Then the Church arrived and set up “shelters for these children” and priests started “visiting communities and forming people on these topics.”
They tried to show them, he said, “that there wasn’t an evil spirit that had damaged the child, and so they then stopped carrying out these practices.”
Bishop Del Río said “semi-nomadic groups” also welcome and no longer reject twins or children with Down syndrome, although he recalled the case of a girl with epilepsy and another who had a tumor on her ear where the parents would not let priests visit them.

http://www.ncregister.com/daily-news/amazon-synod-day-4

As President of the Vatican Dicastery for the Promotion of Integral Human Development, the issues currently being discussed at the Synod of Bishops for the Amazon, are very close to Cardinal Peter Turkson.
Pope Francis called for this Special Synodal Assembly in 2017 indicating that the main objective is “to find new ways for the evangelization of that portion of the People of God, especially the indigenous, often forgotten and without a perspective of a good future, also for the cause of the crisis of the Amazonian forest, lung of fundamental importance for our planet”.
Speaking on the side-lines of the Synod at the start of its second week, Cardinal Turkson told Linda Bordoni that the Dicastery he heads was involved in planning for it from day one.
For me, Cardinal Turkson explained, the Synod is like a link in a chain and he said it’s been quite a long time that he has been following its development, starting with the first meetings between Pope Francis and the Popular Movements.
With the Popular Movements, he said, the focus was primarily on three basic rights: access to land, access to housing and access to work..
Here at the Synod, he continued, many of the same issues have come to light and directly regard the indigenous peoples.
“What are they looking for? Integrity of their land, jobs and ultimately human dignity,” he said.
Cardinal Turkson also spoke of the precious collaboration that has taken place between his Dicastery and the nine Churches of the Amazon region that make up the ecclesial network REPAM.  
“For us, we see a progression stimulated by Pope Francis,” he said.
The Synod is part of an ongoing process
Cardinal Turkson said that it is “a keen sense of interest in the evolution and development of everything that has happened up to this moment” that he is following the Synodal process, and he stressed “It is not a point of arrival.”
He noted that discussions and interventions are bring to the fore many different issues, “some pastoral, some social, some developmental”.
From the point of view of his Dicastery, he said that although his team is deeply involved in the pastoral needs of the people, it is also very much aware of their other needs as well.
The Cardinal said that while it is important to help the indigenous peoples safeguard their culture and their heritage, the Amazon region must not be considered a  museum: “we must help the people of the Amazon to open up”.
Leaving no one behind
“We must help them open up to modernity, to innovation, to development, “ he said, “The people of Amazonia, he said, must not be left behind”.
Cardinal Turkson expressed his belief that the Church’s pastoral concerns must include a clear vision and a programme that facilitates and promotes the growth of Amazonians in the realms of modernity and innovation .
He mentioned the possibility, for example, of offering all peoples the choice of being able to use solar energy and modern means of communications.
“I suspect that mobile phones are there… how do they charge them?” he said.
We need, he said, to recognize the very many factors that promote development and the common good, not betraying their culture, but making life easier and more fulfilling for them.
“This is also part of the vision that I think we need to set ourselves to realizing,” he concluded

https://www.vaticannews.va/en/vatican-city/news/2019-10/amazon-synod-cardinal-turkson-integral-human-development.html

what I would like to know is what will be the reaction of these people if after opening up they decide to develop in a way that is not "ecologically approved."