Darwin and Wallace
Evolution
•Define evolution
•Define natural selection
•Conditions for evolution to occur
•Define adaptation
Natural Selection Pressures
•Abiotic (Non-living)
•Biotic (Living)
•All act in concert
Abiotic Selection Pressures
•Moisture
•Disturbance
•Soil conditions
•Probably less stressful than other habitats
Biotic Selection Pressure
•Predation
•Competition
•Sexual selection
–Matc competition
–Mate choice
Matc Competition
•Intrasexual selection
Matc Choice
•Intersexual selection
Red-Capped Manakin
Sexual dimorphism
Adaptive Radiation
•Rapid diversification
–Cichlids in Africa
–Finches in Galapagos
–Bats in Neotropics
Adaptations – Cryptic Species
Aposematic Coloration
Diversity Gradient
Why are the tropics so diverse?
•Stability-Time Hypothesis
•Interspecific Competition Hypothesis
•Predation Hypothesis
•Productivity-Resources Hypothesis
Stability-Time Hypothesis
•A stable habitat that has been around for a long time is more likely to accumulate species
•Unlikely
•Speciation can be rapid (adaptive radition)
Interspecific Competition Hypothesis
•Law of Competitive Exclusion and Resource Partitioning
•High levels of competition have led to high degree of specialization and species “packing”
Predation Hypothesis
•Predators reduce interspecific competition, allowing more species to co-exist
Productivity-Resources Hypothesis
•Lots of productivity and lots of vegetative complexity for species to exploit
Biogeography
•Match current distribution of organisms with evolutionary history
–Includes consideration of geologic events, including continental movement and formation of barriers (such as mountains)
Biodiversity
•Diversity is described by richness and evenness
What is biodiversity?
•Biodiversity exists at several scales
–Genetic Diversity - Measures variety of different versions of same genes
–Species Diversity - Measures number of different kinds of organisms within a community
–Ecological Diversity - Measures richness and complexity of a community
What is a species ?
•There are several different definitions for species
•We will define species in terms of reproductive isolation
–A species is all the organisms potentially able to breed in nature and produce fertile offspring
How many species are there ?
•Currently 1.7 million species identified
•Estimates range between 3-50 million
–May be 30 million insect species
–Invertebrates make up 70% of all known species, and probably most of yet to be discovered species
Where is biodiversity high?
•Only 10-15% of species identified are found in North America and Europe
•Greatest concentration of species in tropical rainforests and coral reefs
•Biodiversity hotspots
–Have exceptional numbers of endemic species
Biodiversity hotspots
Hotspots
•Identified “hotspots” contain:
–44% of the world’s known species of plants
–28% of the birds
–30% of mammals
–38% of reptiles
–54% of amphibian species
•All in an area of 1.4% of the world’s total land surface!
Why do we care about losing biodiversity?
•Direct economic value
•Indirect economic value
•Ethical and aesthetic values
Benefits of biodiversity
•Food
–As many as 80,000 edible wild plant species could be utilized by humans
Benefits of biodiversity
•Drugs and medicines
–More than half of all prescriptions contain some natural product
–Pharmaceutical companies actively prospect tropical countries for products
–Rosy periwinkle
Ecological services
•Ecological functions that we do not pay for directly
–Processing air pollution
–Purifying wastewater
–Providing clean water
–Carrying out photosynthesis
–Creating soil
•Ecological services are included in ecological economics
Benefits of biodiversity
•Aesthetic and cultural benefits
–Cultural diversity inextricably linked to biodiversity
–Ecotourism can be an important form of sustainable economic development
–Existence (intrinsic) value
Costa Rican Organisms
BIRDS
Aves
•~850 species of birds in Costa Rica
–(~400 in Ohio)
•Wing bars
•Chest color/pattern
•Eye ring
•Eye stripes
•Tail pattern
•Size
•Behavior
Tinamous
Tinimidae
Great Tinamou (Tinamus major)
Ducks
Anatidae
Muscovy Duck (Cairina moschata)
Black-bellied Whistling Duck (Dendrocygna autumnalis)
Blue-Winged Teal (Anas discors)
Grebes
Podicipedidae
Least Grebe (Tachybaptus dominicus)
Chicken-like birds
Cracidae
Great Carrasow (Crax rubra)
Gray-headed Chacalauca (Ortalis cinereiceps)
Crested Guan (Penelope purpurascens)
Quails
Odontophoridae
Crested Bobwhite (Colinus cristatus)
Pelicans
Pelicanidae
Brown Pelican (Pelecanus occidentalis)
Cormorants
Phalacrocoracidae
Neotropic Cormorant (Phalacrocorax brasilianus)
Anhingas
Anhingidae
Anhinga (Anhinga anhinga)
Frigatebirds
Frigatidae
Magnificent Frigatebird (Fregata magnificens)
Storks
Ciconidae
Jabiru (Jabiru mycteria)
Herons
Ardeidae
Bare-throated Tiger Heron (Tigrisoma mexicanum)
Great Blue Heron (Ardea herodias)
Great Egret (Ardea alba)
Spoonbills and Ibises
Threskiornithidae
Roseate Spoonbill (Platalea ajaja)
White Ibis (Eudocimus albus)
New World Vultures
Cathartidae
Black Vulture (Coragyps attratus)
King Vulture (Sarcoramphus papa)
Hawks and Eagles
Accipitrae
Osprey (Pandion haliaetus)
Bicolor Hawk (Accipiter bicolor)
Hook-Billed Kite (Chondrohierax uncinatus)
Swallow-Tailed Kite (Elanoides forficatus)
Broad-Winged Hawk (Buteo platypterus)
Crested Eagle (Morphnus guianensis)
Falcons
Falconidae
Laughing Falcon (Herpetotheres cachinnans)
Crested Caracara (Caracara cheriway)
Rails
Rallidae
Gray-necked Wood Rail (Anamides cajanea)
Jacanas
Jacanidae
Northern Jacana (Jacana spinosa)
Limpkin
Aramidae
Limpkin (Aramus guarauna)
Plovers
Charadriidae
Killdeer (Charadrius vociferus)
Sandpipers
Scolopacidae
Greater Yellowlegs (Tringa melanoleuca)
Gulls and Terns
Laridae
Laughing Gull (Larus atricilla)
Royal Tern (Thallasseus maximus)
Pigeons and Doves
Columbidae
Red-Billed Pigeon (Patagioenas leucocephala)
Parrots
Psittacidae
Crimson-Fronted Parakeet (Avatinga finschi)
White-Fronted Parrot (Amazona albifrons)
Cuckoo
Cuculidae
Squirrel Cuckoo (Piaya cayana)
Groove-Billed Ani (Crotophaga sulcirostris)
Swifts
Apodidae
White-Collared Swift (Streptoprocne zonaris)
Hummingbirds (50+ in CR!)
Trochilidae
Long Billed Hermit (Phaethornis longirostris)
Violet-Crowned Woodnymph (Thalurania columbica)
Rufous-Tailed Hummingbird (Amazilia tzacatl)
Trogons
Trogonidae
Violaceus Trogon (Trogon violaceus)
Resplendent Quetzal (Pharomachrus mocinno)
Mot Mots
Motmotidae
Blue-Crowned Motmot (Momotus momota)
Kingfishers
Alcedinidae
Green Kingfisher (Chloroceryle americana)
Barbets and Toucans
Ramphastidae
Chestnut-Mandibled Toucan(Rhamphastos swansonii)
Woodpeckers
Picidae
Pale-Billed Woodpecker (Campephilis guatemaulensis)
Typical Antbirds
Thamnophilidae
Barred Antshrike (Thamnophilis doliatus)
Ground Antbirds
Formicariidae
Black-Faced Antthrush (Formicarius analis)
Contingas
Cotingidae
Three-Wattled Bellbird (Procnias tricarunculatus)
Manakins
Pipridae
Long-Tailed Manakin (Chiroxiphia linearis)
Jays
Corvidae
White-Throated Magpie (Calocitta formosa)
Other Passerines
•Ovenbirds and Woodcreepers
•Tanagers
•Flycatchers
•Becards
•Vireos
•Wrens
•Thrushes
•Swallows
•Gnatcatchers
•Dippers
•Warblers
•Finches and Sparrows
•Grosbeaks and Buntings
•Blackbirds and Orioles
Tools of the Trade
FIELD INSTRUMENTS
Distance Measurements
Transects
•Can be used for measuring gradients
DBH
Calipers
Spherical Densiometer
Environmental Meter
•Light
•Humidity
•Air Speed
•Temperature
GPS
Flags and Flagging Tape
Costa Rican Culture
HEALTH AND SAFETY
Before you go
•Dental check-up
•Medical check-up
•Obtain adequate prescriptions
•Check State Department website
•Check Centers for Disease Control website
•Medical insurance
•Vaccinations (no special required)
Health Problems
•Hepatitis A is contracted through food or water
•Intestinal problems may occur due to differing flora
–Bottled water and avoid ice cubes
–Bring anti-diarrheal medication
–Intestinal worms from walking barefoot
–Dysentary requires antibiotics
–Giadiasis from infected water
Skin Issues
•Sunblock and hat is essential to avoid sunburn
•Prickly heat caused by tight or dirty clothing
•Athlete’s foot and other fungal infections can be prevented by airing out
–Bring anti-fungal medication
Snakebite
•Will have snakebite in first aid kit
•Watch where you are walking and grabbing
•Avoid long grass
•Don’t reach into holes, under logs, etc. without checking with stick first
•Watch grabbing branches as some snakes are arboreal
•Give a wide berth
If bitten…
•Immobilize limb
•Apply tight bandage between limb and body (finger should still be able to fit underneath)
•Get help
Insects
•Check clothing, shoes, bedding before getting in
•Bring insect repellant
•Wear long sleeves and long pants
•Avoid itching
Chiggers
•Found in dry grassy areas
•Scrub vigorously after contact, especially back of knees, top of socks, waistband, etc.
Ticks
•Pull out ticks with tweezers
•Grab close to head and pull slowly and steadily
No-see-ums
•Undeterred by DEET
•Skin-so-soft works
Malaria
•Rare in CR
•Most common on Caribbean coast
•Mosquito bite prevention
Dengue Fever
•Most common on Caribbean coast
•Transmitted by mosquitoes
Riptides
•Never swim against current
•Swim parallel to shore until out of riptide current
•Riptides most likely 2 hours before and after low tide
•Still area in breaking waves
Theft
•Don’t bring anything that might be stolen
•No jewelry
•Wear cheap watch
•Put valuables in safe place at all times
•Carry passport at all times
AntiochCollege Students 2000