Hunting and Wildlife Trade Flashcards
What is empty forest syndrome?
It’s where forests appear undisturbed but there are actually very few predators or wildlife due to overhunting
Where is hunting the most dominant?
Closest to rivers and roads
In Brazilian Amazonia 1996, rural population density was 1.6 per km^2
N° of game mammals consumed per year was 15.8 million, 148 000 tons
Accessibility-dependent effects of game hunting
Game are detected most at higher distances from nearest access point.
Aggregate bushmeat consumption in the Congo Basin (Africa). 1.8 million km^2
645 kg per km^2 per yr eaten
Each km^2 of tropical forest can only sustainably provide for the annual wild meat needs of a single person
Current hunting rates are highly unsustainable and hunting is a major threat to large-bodied vertebrates in tropical forests
Why does hunting occur?
Subsistence and local trade:
- the poor have no other alternative, only source of animal protein, cheaper than domestic substitutes
Cultural/traditional reasons:
- feathers, leather, bones used as garments, accessories and weapons
- festivals, ceremonies
Religious release:
- legal trade in wild-caught birds, two tempres in Phnom Penh, 680 000 birds per year and $235 000 in profit to sellers
Medicine, luxury meat, skins and skulls:
- huge market for natural medicines, tiger brain cures laziness, bile treats convulsions in children with meningitis, $70 000 in China, rhino horn as status symbol in Vietnam, hangover cure, $97 000 kg,
- luxury meat, local delicacies, pangolin meat and scales used for medicine
- trophy hunting, rarity increases price
Cagebird and pet trade:
beautiful songbirds, reptiles, frogs, invertebrates, mammals, bought because cute and mother usually killed
Direct consequences of hunting?
Faunal changes in the Amazon. Rodents increase, competitive release due to predators being hunted.
Mean body mass decreases.
Decline of larger mammals.
Elephants Between 2002 – 2011:
- Population size declined ~62%
- Lost 30% of its geographical range
- Population <10% of potential size
- Population occupies <25% potential range
Ivory is highly valued in China, Philippines, Thailand, etc.
Extinction of Javan Rhino
Last Javan Rhinoceros (annamiticus subsp.) shot in Cat Tien National Park, VN
Scat sniffer dogs to detect dung: last found 4th Feb 2010
Rhino remains found 29th Apr 2010
DNA from all dung piles & remains match
Rhino horn worth more than its weight in gold
Problem with preventing extinction?
Illegal wildlife trade is extremely lucrative, Lord’s Resistance Army, Janjaweed, helicopters to gun down elephant herds, highly organised crime.
Can drive an anthropogenic Allee effect. Premium on rarity drives extinction
Hunting and wildlife trade driving declines in in many species
Big shifts in biomass and size structure of vertebrate assemblages
Local (near-)extinctions of big vertebrates
Can drive global extinction of particularly valuable species
Indirect consequences of hunting?
Bigger primates ingest bigger seeds, but hunting means loss of diversity which decreases seed recruitment.
JC scenarios of seed dispersal in hunted and non hunted forests
High in non-hunted forest, low in ‘empty’ forest
Compared number of small saplings in hunted and unhunted environments
70% of trees have lower recruitment with hunting
Very few tropical forests are truely unhunted
1.6% Amazon strictly protected and inaccessible to hunters
