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