ornithology: introduction a little over 9,700 bird species live in the world today
TRANSCRIPT
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
Feathers, e.g., for display
Feathers, e.g., for display
Birds of Paradisehttp://www.cornell.edu/video/?VideoID=2398
Feathers, e.g., for displaysound!
Common Nighthawkhttp://www.allaboutbirds.org/guide/Common_Nighthawk/videos
Club-winged Manakinhttp://news.nationalgeographic.com/news/2009/11/091111-birds-
sing-feathers-wings.html
Feathers, e.g., for flightFalcon
Beakshttp://www.youtube.com/watch?v=XzHQ5-lYvrk&NR=1
Beaks
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 SquidBeak
Octopus dofleiniBeak
Adaptations for Flight
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 Modesof Life
Variation Within each Order of Birds(e.g., Shorebirds, gulls, alliesCharadriiformes)
Bill Lengths Vary
Adaptations and Variations within the context of evolution.
Handout:Darwin’s Theory of Evolution
andTheory 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-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 Widowbirdof South Africa
Variation allows and reflects
Niche Partitioning, e.g., in Hawaiian Honeycreepers
Extreme example in wing adaptation
Species NicheA 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 community3. the physical, environmental requirements of the species.
Variation in feet reflect different niches (lifestyles)
Niche Partitioningof the Environment
1. If two species live in the same place, then they feed differently or on different foods.
Woodpecker
Nuthatch
Niche Partitioningof 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.