Cultural dimensions of wildlife in the Anthropocene

Anthropocene defaunation

India Bangladesh

Quiz 7, Online until Oct 2

Quiz 8, Thursday, Sept 28

How many species?• 5 - 9 million non-

bacterial species estimated

• Some estimates range up to 100 million because of potential insect diversity

• 1.5 million cataloged, but many are only descriptions or a single museum specimen

• New species are described every year

Extinction• Calculations suggest that

the current rates of extinction are 100 to 1,000 times natural background levels

• Lose between 1-5% of species per year

• Sixth Extinction – the only one driven by humans

Extinction• Not just megafaunal

extinctions associated with early humans, but ongoing into the present

• The modern record of extinctions caused by humans is extensive

Extinction

• There is evidence that contemporary extinctions, while very high, have not been as high as some had predicted, for several reasons:– Some species thought to be extinct are found again

(soledon)– Species surviving on their own in secondary habitats

and anthropogenic land covers (fisher)– Effective conservation efforts (black-footed ferret)

Rediscovery of soledons in Cuba and Hispaniola (Haiti and Dominican Republic)

Expansion of fishers into suburban and urban areas

Black footed ferret recovery in North America

Signatures of human-associated declines in biodiversity

• Faunal size bias• Faunal homogenization• Extinction debt• Trophic cascades

Faunal size bias• Defaunation in the

Anthropocene is size-specific

• Large-bodied mammals and birds are more susceptible to extinction

• Progressively smaller animals threatened

• Today’s mammals on Earth are very small compared to past

Faunal homogenization

Extinction debt• Lock in of

future extinction of species due to human impacts that occurred in the past or present.

• Time delay between human impact and extinction

Spatial patterns in bird species and extinction debt in the Brazilian Amazon

Trophic cascades

Trophic cascades

Extinction of these large predator species can have disproportionately large effects on the abundances of other organisms and on the structure and function of ecosystems.

What are the top two leading causes?

Human-related causes of biodiversity decline and extinction

Pollution?

Climate change?

Habitat fragmentation?

Invasive species?

Overexploitation from hunting and trade?

Habitat fragmentation• Fragmentation is a

pervasive effect of human presence and the leading cause of extinction

• Direct and immediate effects on organisms

• Results in island systems

• In fragmented islands• Isolated populations• Restricted access to

resources• Inbreeding• Harder to evade predators• Stochastic (random) events

can wipe out small isolated populations

Overexploitation by humans

• Humans exploit prey far more than any other predator

• More than 90% of the mammals and birds that have gone extinct recently (within 500 years) were hunted by humans

Democratic Republic of CongoVirunga National Park, 2008

Quiz 9, Friday, Sept 29th

Types of overexploitation• Hunting for bushmeat• Wildlife trade for

– Pets– Traditional medicines,

art

• Bushmeat – illegal, unsustainable trade in wildlife for income or meat.

Bushmeat

• Bushmeat is illegal as defined by:– Where hunting took

place– Method of hunting – Status of the species

taken • Not the same as

game meat legally hunted, farmed, and sold in a market

• Bushmeat trade endemic in many parts of Africa and Asia

Implications• Biodiversity decline• Trophic cascades• Zoonoses –diseases

caused by pathogens that jump from animals to human– HIV (virus)– Ebola (virus)

What drives the bushmeat trade• Poverty and the

need for an income

• Provides protein where other sources lacking

• Instability in food supply

• Cultural, ceremonial uses of animals

Critiquing the bushmeat poverty hypothesis

• Poverty as a cause of bushmeat is often defined an material deprivation, an economic definition that invokes economic responses

• However, poverty also encompasses– Lack of power, prestige, and voice– Inability to define one’s future and day-to-day

activities• Addressing bushmeat requires more than

economic responses

Bushmeat in context: Cameroon and Liberia

Bushmeat in context• Rather than simply legal vs illegal,

bushmeat needs to be understood in its historical, social, political context

• Range of responses to it, no one best overall solution – Tougher rules about possession of

equipment or animals? – Provisioning of alternative livelihoods,

i.e., market incentives to conserve wildlife or to farm wildlife?

Critiquing the bushmeat concept

• Bushmeat unfairly targets one type of overexploitation specific to a group of people (rural) and a location (the developing world)

Critiquing the bushmeat concept• Bushmeat, as a larger

practice of unregulated or illegal consumption of wildlife, is common across economic circumstances

The passenger pigeon: North American bushmeat

Commercial hunting lead to their extinction in 1914. There were no existing rules and to protect them. If this hunting were to go on today, it would likely be similarly labeled as bushmeat by outsiders that prioritize conservation of biodiversity.

Consumption of turtle in Asia

• Rise of affluence in China due to their rise in economic power led to increased domestic demand for turtle meat

• Turtles collected in poorer countries like Laos, Malaysia, Cambodia, Vietnam

• High prices for live turtles in China drive collection

Demand for turtle meat in Asia has increased illegal and legal hunting pressure on turtles in the US. Turtles are caught here but sold and exported to China and other Asian countries where economic growth has increased household incomes. Many states are now considering legislation to more tightly control turtle hunting. Turtle hunting has been legal in many states, but the hunting regulations (length of season, number of turtles taken) need to be reassessed in light of increasing pressure