Ecological Roles of Birds
The Importance of Birds in the Ecosystem
It's nearly impossible to find a habitat on the globe without birds. Their presence is proved by holes pecked in tree bark or the remnants of nests. Birds constitute an indispensible part of the ecosystems they inhabit, and their activity is of great importance for the effective functioning of different ecosystems.
Birds contribute to ecosystem health in a significant way and provide many direct benefits to people. The term "ecosystem services" was coined by the Millennium Ecosystem Assessment under the initiative of the United Nations. It pointed out four broadly defined ecosystem services and in this article we will research how the activities of birds across the globe impact each of them.
Actions within this category are necessary for the production of all other ecosystem services, nutrient cycling and the soil formation in particular. This category is considered to be the basis of processes without which other ecosystem services are impossible to produce.
Birds contribute to these services by nutrient cycling. For example, scientists researched the islands in the Gulf of California and found out that when birds roosted on them, the guano deposits left by birds contributed to faster growth of a variety of plants on the islands. This example also shows how different habitats are connected and impact one another. The primary productivity in the ocean influences the number of fish it can support, and this, in its turn, regulates the number of birds that can feed on these fish, which impacts the number of birds that will roost on the island and leave guano deposits, dictating the primary productivity and food web structure on the island. This example proves the primary law of ecology formulated by Barry Commoner in 1971.The law says everything is connected to everything else, and we clearly see that birds serve as a vector for nutrients between aquatic and terrestrial habitats.
Provisioning services include products people harvest from ecosystems and there are many examples that illustrate how birds positively impact the raising of crops and livestock.
When farming rice straw in California the fields get flooded after the harvest is gathered. This creates habitat for waterfowl that forage there. As the birds dive to find grain and invertebrates they tear, shred, and churn up the straw lying on the ground. Such activities of birds increase microbial decomposition. As a result the waterfowl presence prevents the need for autumn tillage, saving farmers a great deal of money.
Birds can benefit the agriculture by regulating pests. For example, due to the presence of insect eating birds in Guatemalan coffee plantations the leaves of crops were less damaged by herbivorous pests.
Mutualistic relationships between birds and livestock can significantly benefit humans. Many birds forage on insects that live on livestock like cattle. For example, cattle egrets feed this way. In Pakistan, birds are good at preying on ticks that infest cows, so cows become healthier and produce more milk. Such activity of birds is sometimes even more effective than pesticides. As a result people not only save money on expensive pesticides but also get more productive and healthier livestock.
Regulating services refers to all benefits gained from the regulation of ecosystem processes. These are carbon sequestration, waste decomposition, and air purification. Birds perform an important role of scavengers in most ecosystems. Not only vultures can remove the carcasses of dead animals. Scavenging by birds serves as a natural method of waste disposal in many areas. In fact, it prevents the outbreak of many diseases. In India, when the number of vultures dropped the population of feral dogs increased and consequently rabies outbreaks and dog attacks on people increased too.
Also birds help promote forest growth. They disperse plant seeds during foraging. Birds pick a seed or fruit from a plant and often fly off carrying it, so it gets transported to a new place where it can germinate. This way birds help reforest deforested lands, reducing the cost of restoration.
The cultural services are more intangible and provide less material benefits. They include spiritual enrichment and the appreciation of nature.
Probably the best example is bird watching, which is often used to promote ecotourism. A number of nature centers and nonprofit environmental organizations organize bird watching tours to foster love for nature. Zoos may purchase beautiful or rare birds to attract more visitors and generate more revenue.
Birds have always played a significant role in many cultures across the world. For instance, Native Americans believed eagles to be sacred messengers that can deliver prayers to the spiritual world. Eagle feathers were known to possess sacred powers. In many religions, vultures were revered as creatures playing an important part in mythology and traditions.
This article zeroed on ecosystem services that birds provide and how birds benefit the environment. But it would be wrong not to mention that birds also provide numerous economic benefits. Many nations hunt birds and eggs for food. In Malaysia, the nests of swiftlets are harvested to be used in cooking. They are an extremely expensive delicacy and a quality nest can cost over $700. In some cultures birds are widely used in traditional medicine.
The ecological role of birds is invaluable and the given examples describe only some of the ways how birds contribute to ecosystem services. It is impossible to calculate the monetary benefits people get from birds but if such attempts were made the numbers would reach billions of dollars annually.