**3. Conclusion**

"We are surrounded" is a phrase that indicates the imminent of losing a battle.

The fever of a new fondness for nature and the trafficking of exotic species, leads to conservationism and the authorities, to inaction in situations caused by alien populations of animals that have been introduced into the natural environment, intentionally (as experiments), by escapes from captivity or liberations due to thought and militancy, such as the American mink, in Europe.

We wish this epilogue is not the last cry for help in favor of various species, endangered by well-intentioned human actions, that have not foreseen the "collateral damage", or yes, in programs or actions for the recovery or reinforcement of populations animals, and that they do not seem to present a clear reading of the problems caused, nor do they seem to set limits to the density of the species.

Any project, or monospecific conservation program, must consider the effects that it may cause to other populations, set temporary limits, in the short term, in which the impact caused to other species is reviewed, and the performances reduced or suspended.

As humans, we have intervened and altered so many balances and ecosystems that we have a responsibility to mitigate the damage caused. 150 species are going extinct every day. We have lost forever, thousands of species without having come to know them. This is sad and irresponsible. It would be sadder, still, to allow those that we already know to be lost and not get to know those that remain to be discovered.

We have a lot of work to do. We have a lot of problems. We are surrounded …
