A Bird's Eye View of Intensive Agriculture
Covering Vast Regions, Removing Water Sources and Using Chemicals
Large-scale intensive agriculture creates vast regions of featureless landscapes, replacing water sources and diverse food webs with crop monocultures. Intensive agriculture differs from other types because of its magnitude and use of chemicals and pesticides.
Grasslands, wetlands and forests usually full of water, shelter and food sources for migrating birds can become featureless "eco-deserts" after being converted by intensive agricultural land use.
Intensive agriculture taxes limited water supplies that help sustain natural productive habitats. As water is diverted to agricultural lands, migratory bird wetland habitat can be destroyed. For example, extensive use of water for agriculture along the 2300 km long Colorado River has resulted its delta running almost completely dry much of the year.
Pesticides, herbicides and fertilizers are dangerous chemicals that disrupt food webs and enter natural environments through agricultural waste water runoff. They kill many plants and animals and contaminate wetlands and aquifers.
Birds can swallow pesticides directly by consuming contaminated food or water, or indirectly by landing in contaminated habitats. Pesticides can also be absorbed through the skin, or inhaled when pesticides are applied aerially.
Herbicides kill plants that play important roles in habitats and that birds eat. These plants help create the complexity of habitats that sustains complex food webs. Habitats and food webs make the productive ecosystems that sustain many plant and animal species at once, including migratory birds.
Fertilizers disrupt food webs by injecting extremely high amounts of nutrients into natural environments. Algae and bacteria that thrive on these fertilizers grow at very fast rates, using up all the oxygen in water supplies. This can lead to the deaths of other plants and animals and have a dramatic effect on habitats and food webs.
Fragmenting the Landscape
Intensive Agriculture Breaks Up Habitats into Small Ineffective Pieces
Many migratory birds in North America use habitats near intensive agricultural lands as summer breeding sites or refuelling sites during migration.
These monocultures break up and fragment habitats used by migrating birds, making it increasingly difficult to complete migration through vast areas of intensive agricultural regions.
Spaces between usable habitats become greater and habitats become smaller. The effects of smaller, less productive and contaminated habitats for these birds can result in the disappearance of suitable breeding sites, plants and animals to eat and clean water.
Although more than 400,000 square miles of grass prairie once covered the United States, 95 percent of those grasslands have been permanently destroyed or converted to agriculture.
In the past three centuries, world-wide cropland and pasture have expanded six-fold due mainly to exponential human population growth.
Interactive Range Maps
See what migratory birds in your area migrate to North American Prairies using The Cornell Lab of Ornithology's Neotropical Interactive Range Maps or check out these examples: Cackling Goose, Orange-crowned Warbler, Wood Duck
See "A Bird's Eye View" of Intensive Agriculture examples on the WMBD Event Google Map: Example of Fragmented Habitat, Example of Intensive Agriculture Water Use
Register a WMBD Event
Register a WMBD event to raise awareness about the effects of intensive agriculture on migratory birds in your area and receive WMBD posters and stickers to support your event.
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