Many kinds of migrations and migratory pathways exist . They are as ancient as life on Earth. Most are massive, round-trip seasonal journeys by land, water or air. Others are movements of countless individuals in a single direction at intervals of a few years, sometimes referred to as emigrations and “ invasions .” Whatever the case, animal migrations transcend the political borders shaped by a dominant species, Homo sapiens , which mostly reflect the consequences of past wars and current struggles. Borders are no more than artificial boundaries that do not echo the intricate webs of lives of communities, populations, and species.
Why migrate?
Migrations are driven by an instinct of self-preservation because survival is at stake. Many species escape harsh winters or blistering summer heat, in need of more benign conditions to breed and nurture their offspring. Other species migrate in search of water, food, and shelter, following seasonal changes in the availability of those resources. And still, others are escaping predators or other dangers. For many, it´s simple: migrate by whatever means available, even if it means walking, or die, legally or illegally, depending on the color of the lens through which one looks. It´s a survival strategy that has worked for thousands of species for eons, including humans .
Countless individuals of all ages, mostly the very young and the very old, die while migrating. Some, however, succeed and ensure the survival of populations far away from their places of origin. The secret to success is to migrate in large groups that offer protection from predators because the higher the number of individuals in the group the smaller the odds that any single individual will be attacked . Risks are shared, as masses serve to protect. In addition, when the number of migrants is high, the possibility of finding water, food, and shelter increase because you’ve got more scouts on the trail with you.
In many mammals, the young —pioneers by instinct— are the ones that initiate the migration , moved either by the need to establish their own packs or territories or because they simply have been pushed away by dominant adults. Whatever the reason, youngsters frequently wander looking for new horizons as advance parties that, eventually, establish toeholds in new territories.
When living conditions improve in their places of origin, migrants might return home
. Many, however, choose to remain in their newly acquired home and never return, either because they become part of new communities that adopt them, or because they establish their own new communities. And an influx of migrants delivers priceless benefits to the new communities . Migrants can contribute with an important genetic variation to the existing population as well as cultural and educational exchanges, all of which, in the end, enrich and fortify the species as a whole. To put it bluntly: migrants are the fuel that helps to sustain and upgrade cultural and genetic diversity . Diversity is critical to the survival of a species, especially in the face of any type of environmental challenges.
Consider global climate change
, the greatest challenge of our generation, that appears to be shifting climatic regimes in both the northern and southern hemispheres towards the poles. Mass migrations might be precipitated in unimaginable ways . Many communities, populations, and species will be unable to adapt to the changing local conditions at the pace needed to survive. Those with restricted ranges or dispersal abilities will likely disappear, while those with wider ranges and greater dispersal capacities will endure. Climate change is already beginning to dramatically reshuffle ecosystems and change the distribution patterns of life across the Earth. The pace of change will, inexorably, surpass the natural dispersal capacity of most species.
Migrations transcend geopolitical, cultural, religious and economic boundaries
. They are an inalienable right of the species in the natural world. We will not be able to understand, value and preserve migrations merely through isolated, unilateral policies and actions, whether in the form of threats, walls or by hiding our heads in the sand. Protecting these mindboggling, ancient natural wonders demands from us wide-ranging, long-term policies and effective action to secure feeding, breeding and transit areas across large, multi-country landscapes. While individual actions are the responsibility of each nation, international cooperation is imperative.
Our disastrous past efforts to protect migrants should impel us to do much better now. It doesn’t matter if we are talking about Asia , Africa , North America , South America , Europe , Australia , or even the frozen Arctic . There are migrants everywhere . In the northern hemisphere, in particular, transboundary migrations weave together developed and developing nations. Migrants travel South to North, East to West. We cannot use the social, economic and political challenges facing each nation to offer an easy, empty excuse for inaction. Too much is at stake for us and for our planet.
Whereas many of the world's most spectacular animal migrations are vanishing in front of our eyes, protecting migrants is an essential collective challenge. As migrations dwindle or disappear, all countries—rich and poor, without exception—lose the benefits and diversity associated with these natural wonders.
To all migrants, with admiration and solidarity, but especially to our Central American sisters and brothers, we wish you well on your journey.