Samenvatting
summary of the course wildlife ecology and conservation
A summary and lecture notes on the course of wildlife ecology and conservation
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Wildlife conservation and ecology – REG328061. Intro
Biodiversity:
Different levels →
o Genetic
o Species
o Ecosystem
Spatial component →
o Richness
o Evenness
Recessive
Dominant
Temporal component → Over time increase & decrease (mega extinction), but in the end over
time diversity goes up (trend is up!)
Dimensions of biodiversity:
o Functional → Contribution species to ecosystem, Measure by looking at traits
o Phylogenetic → How related are species?
Diversity causes stability
How much biodiversity is lost?
Large mammals occurred everywhere, lost in most parts → not known if it is by humans or climate.
Clear link extinction animals and antropocene, but it also saved some mammals by conservation actions.
Why is the loss of biodiversity problematic?
Value statements underlying wildlife conservation:
Diversity of organisms is good → Human induced extinction is bad
Heterogeneity & ecological complexity is good → ecological processes should not be simplified
Evolution is good → not half or alter evolution
Biotic diversity has intrinsic value → Species have value themselves
What are causes of biodiversity loss?
Habitat fragmentation and exploitation is high in mammals
Main threats:
Habitat loss:
o Agriculture
o Logging
o Development (e.g. housing)
Direct mortality
o Hunting (overexploitation)
o Invasive species
Conservation action prevented:
, Hunting & collecting terrestrial animals
Agriculture and aquaculture
Dilemma of world population growth
Natural resources increasingly needed -> degradation -> undermines future use
Key factor in species threat: population density of people
Not always a relationship -> less mammals in very dense Europe already, not that many threatened
now
Slowing/halting human pop growth
By
o Empowering & educating women
o Access to contraception
Problem: economies based on growth
o Change in mindset needed
o More protected areas
Genetic diversity (GD)
Low GD can reduce:
Pop viability
Resistance to diseases
Climate change
No evidence as direct cause of extinction
Expected to have negative (indirect) effects in future
Anthropogenic (human caused) threats
Largely determined by:
Income
Pop density
Development activities
Effective conservation measures:
Solutions; what can we do? ◦ More substantial conservation efforts
◦ Proactive policies (e.g. shifts in agricultural practices)
◦ Improved land-use planning:
Land sharing → Less efficient, but life together
or
Land sparing → spare extra land for animals, more effective land use.
, Shifting diets
Conservative successes
◦ >31 bird species saved from extinction by conservation programs
◦ Protected areas cover 14% of land surface
◦ Eradication of invasive species
◦ Captive breeding & re-introductions
Future treats:
Current + increased but uncertain threat of climate change effects
2. Overexploitation
Oceans
o Fishing
Wildlife
o Hunting & poaching
o Relationship with overfishing (Coastal areas without enough fish -> turn to bushmeat,
more hunting)
Forests
o Timber extraction & logging
o Fuelwood collection & charcoal production
Forest loss (forest itself not exploited)
◦ Agriculture
◦ Road building and urbanization
More accesible → more exploitation
Tragedy of commons o Incompletely defined & enforced property rights o Users do not consider social
benefits & costs o Benefits for individual, negative effects for all o Harmful effects on 3rd parties:
depletion of wildlife
When people own area → become responsible
Extent of problem
Overexploitation 1 of 5 main threats
1.5 km2 net forest loss between 2000-2012
o Tropics: agriculture & urban expansion
o Boreal: fires
Large mammal species: pop decreased after humans entered continent
301 mammal species threatened due to hunting
o Less in developed countries (EU), all in developing countries (Africa) -> hunting not
needed & lot of mammals already extinct
, o Mostly in Asia, Africa & South-America
o Larger body mass (kg) -> higher chance of being hunted
o Also affects birds (parrots as pets)
Causes of overexploitation ◦ Forests - Timber/logging
- Fuelwood/charcoal
- Uncontrolled fires
- Livestock grazing
◦ Hunting (bushmeat)
- Food
- Medical products
- Ornaments
- Pet trade (parrots)
Most affected species:
Ungulates among large-sized mammals
Primates among medium-sized mammals
Bats among small-sized mammals
Human induced megafauna extinctions
Hunting or climate change?
Ongoing debate:
Global geographical distribution of extinct species: humans the main cause (Sandom et al 2014)
Ancient DNA: climate change the main cause (Cooper et al. 2015)
Causes increased hunting pressure in tropical forests
o Loss of forest
o Increase in human pop size(people get very old)
o Urbanization
o Increased access (roads & fragmentation)
o Mobility of hunters
o Modern hunting technologies (weapons)
o Commercialisation
o Extractive industries (logging)
Empty landscape: e.g. South east Asia → hardly any wildlife by overexploitation.
Bushmeat hunting on African Savannahs
o Elevated demand (for meat)
o Human encroachment
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