Birds & People

Good Things Birds Do For Us Food Eggs 2 billion chickens per year (18 kg/person) 100 million turkeys 11 million ducks

Good Things Birds Do For Us Feathers - ornamentation

Good Things Birds Do For Us Guano - fertilizer Peruvian islands

Good Things Birds Do For Us Insect control Northern Flicker removed >60% of over-wintering corn- borer larvae from Mississippi cornfield Bird houses - Purple Martin - mosquitoes

Good Things Birds Do For Us Rodent control Hawks, owls - small rodents

Good Things Birds Do For Us Scavengers Vultures, gulls, crows

Good Things Birds Do For Us Recreation Hunting - economics Falconry

Bad Things Birds Do To Us Crop damage U.S. - 6 million bushels of corn/year Waterfowl, doves, crows/jays, robins, starlings, blackbirds, turkeys

Bad Things Birds Do To Us Competition Wild game, fish

Bad Things Birds Do To Us Fouling of roosts Droppings - pigeon 2.5 kg/year Odor, corrode masonry Histoplasmosis, chlamydiosis

Bad Things Birds Do To Us Airport problems Plane strikes ~15,000 collisions/year in U.S. $300 million/year 300 people deaths Gulls - 31%, blackbirds - 13%

Bird Trauma Through Time 3 million years ago - 25% of birds went extinct at beginning of Pleistocene Major climatic changes –Habitat changes –Distribution changes –Viability impacts

Human Impacts Humans have become a major factor affecting birds ~1000 species now threatened

Human Impacts Destruction of habitat Excessive human predation Introduced species Toxins

Human Impacts Many bird groups especially problematic Neotropical migrants Grassland species Migrant shorebirds Seabirds of Southern Hemisphere Rain forest species with restricted ranges

Human Impacts 10 countries now harbor 400 threatened species with restricted ranges

Human Impacts Past 300 years ~90 bird extinctions 91% due partly to species introductions (especially on islands) 32% due partly to habitat changes 25% involved excessive human predation

In the U.S. Endangered species - one that is in danger of extinction throughout all or a significant portion of its range Threatened species - one that is likely to become endangered in the foreseeable future throughout all or a significant portion of its range

Small Island Effect Island-bound flightless & nesting seabirds Susceptible to rats, hogs, goats, cats brought to islands by ships/sailors Dodo in western Indian Ocean Great Auk of northern Atlantic Ocean –Food to resupply ships that had crossed Atlantic

Hawaiian Island Problems Bird pox & malaria brought by introduced mosquitoes Worse problem caused by first Polynesian colonists 1500 years ago Lowland forest destruction - extinction of 39 spp. of land birds

Modern Threats Human activities directly responsible for deaths of ~270 million birds/year Does not include losses due to destruction of breeding habitat, interference with reproduction

Modern Threats Hunters million Vehicle collisions - 57 million Windows - 80 million –2/3 of hunter kill –IL house - 61/year –NY house - 47/year

Modern Threats CATS! 1 billion!

Environmental Poisons Pesticides - DDT Bald eagle, other raptors Reproductive failure % thinning of eggshells Reproductive output cut by nearly 2/3 until DDT ban Recent recoveries to near normal

Environmental Poisons Xenobiotics Chemicals that interfere with endocrine system Disrupt normal course of development Fungicides, herbicides, insecticides, assorted chemicals, food products, metals

Environmental Poisons - PCBs May lead to: Thyroid dysfunction Compromised immune systems Decreased fertility Decreased hatching success Gross birth deformities, behavioral abnormalities, sex reversal Cormorants

Environmental Poisons - PCBs Extra eggs Female-female pairings Feminization High male mortality Embryonic/chick mortality Reduced growth Deformities Altered nest defense, incubation behavior Herring Gulls Lake Michigan, Ontario