Ornithology: Introduction A little over 9,700 bird species live in the world today.

The diversity of life is very large. Planet Earth is home to an incredible variety of animal life. There are about 4,600 mammal species (one of which is humans), about 9,700 bird species, about 8,000 reptile species, about 4,700 amphibian species, and 25,000 different kinds of fish. Insect species are estimated to be about 10 million species.

The world's smallest bird is the Bee Hummingbird found only in Cuba. (Light Direction and Angle of View produces perception of different colors) 1.8 grams (penny=2.5g) 5cm

The world's largest bird is the Ostrich

Ostriches usually weigh from 90 to 130 kg (200 to 285 pounds), and are 1.8 m to 2.7 m (6 feet to 9 feet) in height

Characteristics and Adaptations The defining characteristic of birds is the presence of feathers. All birds have feathers and having feathers (today) is completely unique to birds.

Feathers, e.g., for display

Birds of Paradise

Feathers, e.g., for display sound! Common Nighthawk Club-winged Manakin

Feathers, e.g., for flight Falcon

Beaks

Beaks

Lesser Nighthawk Hummingbird

Not all animals that have beaks are birds Hawksbill Sea Turtle

Not all animals that have beaks are birds Giant Humbolt Squid Beak Octopus dofleini Beak

Adaptations for Flight

e.g., efficient uptake of oxygen – compare to Humans: 21% oxygen in and % out

Adaptations for Flight e.g., efficient uptake of oxygen – compare to Humans: 21% oxygen in and 16% out Birds: Peter Ward found that at sea level birds breathe 30 percent more efficiently than mammals and at 5,000 feet in elevation birds are 200 percent more efficient.

Leg bone length modified for balance, e.g., to incubate eggs.

Adaptation for perching.

Adaptations for Different Modes of Life

Variation Within each Order of Birds (e.g., Shorebirds, gulls, allies Charadriiformes)

Bill Lengths Vary

Adaptations and Variations within the context of evolution. Handout: Darwin’s Theory of Evolution and Theory of Natural Selection

Adaptation – any inherited characteristic that helps an organism to survive and reproduce. Coevolution – the evolution of two species living together such that they influence each other’s adaptations.

Adaptation - Coevolution Erythrina crista-galliErythrina crista-galli (crybabytree) – The anthers are positioned to dust the top of the hummingbird as it drinks.

Theory of Sexual Selection If one sex has it and the other sex likes it, sexual selection can lead to any ARBITRARY trait, as long as it doesn’t impair survival too much.

Long-tailed Widowbird of South Africa

Long-tailed Widowbird of South Africa

Variation allows and reflects Niche Partitioning, e.g., in Hawaiian Honeycreepers

Extreme example in wing adaptation

Species Niche A species niche consists of the combination of: 1. the physical space (habitat) occupied by individuals of that species, 2. the functional role (“life style”) that species has in the community 3. the physical, environmental requirements of the species.

Variation in feet reflect different niches (lifestyles)

Niche Partitioning of the Environment 1. If two species live in the same place, then they feed differently or on different foods.

Woodpecker

Nuthatch

Niche Partitioning of the Environment 1. If two species live in the same place, then they feed differently or on different foods. 2. If two species feed similarly, then they live in different places. 3. Each species has structural modifications to adapt to its niche.

4. Niche partitioning of the environment allows coexistence of different species in the same general area. 5. The competitive exclusion principle states that niches of different species in the same area do not overlap.