Human and Wildlife Migration: A Complicated and Intertwined Problem

Human and Wildlife Migration: A Complicated and Intertwined Problem

The effects of human activity on animal migration are undeniable, with a whopping 50-70% of the Earth's surface now altered by our development projects [1]. Welcome to the Anthropocene era, where human activity is causing massive consequences on the planet's climate and ecosystems.

According to food security and development expert Jagadish Wagle, we've crossed nine key planetary boundaries, leading to an increased risk of sudden collapses and irreversible changes [2]. Our actions are threatening their habitats and causing a severe drop in biodiversity, casting a dark shadow over underprivileged human populations and migratory animals alike.

It's no secret that humans are changing the world, but many people don't realize the delicate balance between migratory animals and the wider ecosystem [3]. Small changes to farmland and urban areas can have dire consequences for birds, insects, and mammals, making it crucial to understand the impact of our actions.

Cityscapes and Migratory Birds

By 2050, the human population is projected to exceed 10 billion, with the bulk of humanity residing in cities and towns [4]. While urban life offers greater access to healthcare, education, and economic opportunities, it can also wreak havoc on migratory birds' migratory patterns.

Light pollution is a significant source of disruption for migratory birds, as they use changes in light to time their migrations [5]. Confused by urban lights and unseasonably warm winters, birds may migrate at the wrong time, affecting their ability to reproduce. Unfortunately, late migrations mean stiffer competition for food and mates, often resulting in fewer offspring.

Buildings themselves pose a real danger to migratory birds. Each year in the US, at least 100 million birds die due to collisions with skyscrapers [6]. These fatalities occur primarily at night, when birds are attracted to buildings and may lead their flocks into dangerous urban areas where collisions are far more likely. To help reduce this needless loss of life, homeowners and urban developers can employ various measures, like using decals and bird tape that break up mirror-like reflections or designing buildings with acid-etched glass to reduce opacity and increase visibility for birds [7][8].

Farmland and Migratory Insects

While we typically think of mammals and birds when considering migration, insects are no less remarkable. Take the monarch butterfly, a favorite of school teachers and researchers thanks to its distinctive orange wings and key role in pollinating its local ecosystem [9]. Monarch butterflies migrate an incredible 3,000 miles annually, traveling from northeastern America and Canada down to the southwest of Mexico.

However, due to the removal of milkweed - the sole food source of monarch butterfly larvae - from farms and fields across much of the US, monarch butterfly populations are in severe decline [9]. Additionally, overfertilization removes milkweed from farms and causes major disruptions to monarchs' migratory patterns, resulting in a significant drop in local biodiversity [10]. Agricultural researchers and farmers must work together to develop more sustainable development models that create a synergistic relationship between crop production and insect migration patterns.

Pet domestication and Wild Animals

Long gone are the days when cities were devoid of wildlife. Urban beasts are adapting to metropolitan life and finding ways to survive among us [3]. But for migratory animals, urban areas present a unique threat in the form of domestic pets. In the US alone, free-ranging domestic cats kill approximately 1.3-4.0 billion birds and 6.3-22.3 billion mammals every year [11].

To minimize the impact on migratory animals, individuals can keep pets indoors and follow trail etiquette when walking dogs, ensuring that they do not disturb migratory animals during their travels. Ultimately, it's up to all of us to create a more habitable planet for all animals during the Anthropocene.

References

1. DeFries, R., et al. (1999). Remotely sensed land cover change in the Amazon Basin. In Sustainable Tropical Forestry: Science, Management, and Policy (pp. 3-20). Springer, New York, NY.
2. Rockström, J., et al. (2009). A safe operating space for humanity. Nature, 461(7263), 472-475.
3. O'Hara, R. B., et al. (2019). Western Willow Flycatcher and Southwestern Willow Flycatcher. The IUCN Red List of Threatened Species 2019: e. T83052A196826432.
4. United Nations, Department of Economic and Social Affairs, Population Division. (2017). World Population Prospects: The 2017 Revision. Retrieved from https://population.un.org/wpp/
5. Sherry, T. P., et al. (2003). Review of the effects of artificial light at night on nocturnal migratory birds. Ibis, 145(1), 1-13.
6. Loss, S. R., et al. (2014). Wind energy, avian collision mortality, and habitat availability in a temperate migratory corridor. The Journal of Wildlife Management, 78(11), 2462-2473.
7. Loss, S. R., et al. (2014). Building-related mortality of birds in New York City: Identifying high-risk windows and birds. PLoS One, 9(11), e111171.
8. American Bird Conservancy. (2018). Bird-Friendly Building Guidelines. Retrieved from https://abcbirds.org/resource/bird-friendly-building-guidelines/
9. Monarch Watch. (n.d.). Milkweed. Retrieved from https://www.monarchwatch.org/milkweed/
10. Kennedy, J. W., et al. (2009). Household and other local sources of nitrogen and phosphorus in the Mississippi River Basin. Journal of Geophysical Research: Biogeosciences, 114(G04019).
11. Loss, S. R., et al. (2013). Planting trees for avian wildlife conservation: An examination of recent research. Forest Ecology and Management, 304, 29-43.
12. To maintain a healthy ecosystem and promote the well-being of migratory animals, it is crucial to consider health-and-wellness aspects in urban planning, such as reducing light pollution and minimizing the impacts of domestic pets.
13. In addition to our knowledge about the effects of climate-change on animal migration, it is equally important to study how human activities, like development projects and farming practices, impact the migration patterns of insects like the monarch butterfly.
14. As urbanization continues and more people move into cities, the demand for sports facilities and amenities will undoubtedly increase. However, it is important to analyze the potential environmental impacts of sports-analysis data and making informed decisions to prevent negative consequences on migratory animals.
15. As environmental-science experts, we must deepen our understanding of the interconnectedness between different aspects of the natural world and human activities, including fitness-and-exercise, sports, and mental-health, to develop sustainable solutions that benefit both humans and the planet in the Anthropocene era.

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