In the following passage, some words have been deleted. Read the passage carefully and select the most appropriate option to fill in each blank.

The (1) _______ of birds is one of the most fascinating aspects of the natural world. From the soaring flight of eagles to the colourful plumage of parrots, birds have evolved a wide range of (2) _______ to survive and thrive in their environments. One of the most remarkable adaptations is the ability of some birds to migrate over vast distances, often crossing oceans and continents to reach their breeding or wintering grounds. However, many species of birds are facing threats to their survival, such as habitat loss, climate change and (3) _______ by humans. In response, conservation efforts have been put in place to protect these birds and their habitats. This might involve creating protected areas, restoring degraded habitats or reducing the use of pesticides and other harmful chemicals. Another important aspect of bird conservation is (4) _______ populations to track changes over time and identify emerging threats. This can be done through citizen science programmes or through more intensive efforts led by conservation organisations. Ultimately, protecting birds and their habitats is not only important for the birds themselves but also for the broader ecosystems they are a part of, and the many benefits these ecosystems provide to humans, such as clean air and water, and (5) _______ opportunities.