David Attenborough Presents: Hummingbirds - Jewelled Messengers | Free Documentary Nature

This paragraph introduces hummingbirds as extraordinary animals with unmatched aerial prowess and their significance in the natural world. It explains that hummingbirds, known for their glittering colors and fast-paced lives, are tiny creatures that rely on flowers for their nectar, which fuels their frenetic lifestyle. The paragraph also touches on the evolutionary history of flowering plants and how hummingbirds became their primary pollinators, replacing insects in certain conditions, particularly in the cold and damp mornings of South American forests.

The second paragraph delves into the evolutionary partnership between hummingbirds and flowering plants, which began around 50 million years ago. It describes how the ancestral hummingbirds, initially insect and spider eaters, started visiting flowers possibly to extract insects and eventually began to pollinate them. Over millions of years, hummingbirds evolved to have lighter bills, longer tongues, and greater agility to better suit their new roles as pollinators. The paragraph also highlights the high-energy demands of hummingbirds and how they adapted to live on an 'energy knife edge'.

This paragraph discusses the high-energy lifestyle of hummingbirds and the adaptations they have made to meet their energy needs. It explains that hummingbirds consume more than their body weight in nectar each day and that hummingbird-pollinated flowers produce a large amount of nectar. The plants have evolved to produce flowers that are long and thin, requiring hummingbirds to hover and use a lot of energy to reach the nectar. The paragraph also mentions the development of hummingbird's unique flying capabilities, including their ability to fly in all directions, which is unmatched among birds.

The fourth paragraph introduces a high-tech company in California that invented a robotic hummingbird, capable of mimicking the flight of a real hummingbird by gaining power on both wing strokes. This robotic bird is so realistic that it can even fool real hummingbirds. The paragraph describes an encounter between a real hummingbird and the robotic one, highlighting the real bird's protective behavior towards its nectar source.

This paragraph focuses on the extreme energy demands of hummingbirds' flight and the adaptations they have to make to survive. It describes how hummingbirds have the highest oxygen demand of all vertebrates, with their wings beating up to 80 times a second. The heart rate of a hummingbird can increase from 400 beats per minute when perched to 1,200 beats per minute in flight. The paragraph also explains how hummingbirds go into a state of torpor during the night, reducing their body temperature and heart rate to conserve energy.

The sixth paragraph discusses the dietary needs of hummingbirds beyond nectar, specifically their need for protein. It describes how hummingbirds catch insects on the wing with remarkable precision and skill, which is essential for building muscles and replacing feathers. The paragraph also touches on the challenges hummingbirds face in avoiding choking on the insects they catch.

This paragraph explores the complexities of breeding for hummingbirds, from the female's role in building the nest and tending to the eggs to the male's brief but energetic courtship display. It highlights the difficulties hummingbird chicks face, with few reaching adulthood due to the constant need for nourishment and the risks associated with being inconspicuous.

The seventh paragraph describes the vibrant and iridescent colors of hummingbird feathers, which are not produced by pigments but by layers of microscopic air bubbles that refract, reflect, and recombine sunlight. These colors serve as a warning signal to intruders but can also be hidden from enemies. The paragraph also discusses the aggressive behavior of hummingbirds when defending their territory and nectar supply.

This paragraph discusses the concept of temporary territories in hummingbirds, particularly in Northern Brazil where cactuses reveal their flowers in the afternoon. Hummingbirds remember when the nectar becomes available and feed on it, carrying away the plants' pollen on their bills. The paragraph also highlights the unique adaptations of different hummingbird species to various habitats, including the high mountains of the Andes.

The eighth paragraph examines the specialized relationships between certain hummingbird species and specific flowers. It describes how some plants, like the angel's trumpet and the heliconia, have formed close bonds with particular hummingbirds, offering them exclusive access to nectar in exchange for effective pollination. The paragraph also discusses the unique adaptations of these hummingbirds, such as the sword-billed hummingbird's extraordinarily long bill.

This paragraph introduces the micro hummingbirds, the smallest warm-blooded creatures on Earth, which weigh as little as two grams. It discusses their unique behavior and how they compete directly with insects. The paragraph also raises the question of why these tiny hummingbirds are not attacked by larger territory owners and suggests that their small size and insect-like flight may fool the bigger birds.

The final paragraph follows the migration of ruby-throated hummingbirds, which must travel thousands of kilometers from Canada to escape the winter. It describes their stopover in Rockport, Texas, where they gain weight by converting nectar into fat. The paragraph also discusses the challenges they face during their nonstop flight across the Gulf of Mexico and the use of Doppler radar to track their journey.