Status: Schipper et al. 2008 Status of Land and Marine Mammals: Diversity, Threat, and Knowledge Flashcards
An assessment of the conservation status of all known mammals was last undertaken by the International Union for Con- servation of Nature (IUCN) in 1996.
What are the problems with this data?
It is based on categories and criteria that have now been superseded, and the assessments are officially outdated for about 3300 (out of 5487 [60%]) mammals never assessed since
What do the species richness and phylogenetic diversity
maps look like for mammals and what is the significance?
A = species Richness
B = phylogenetic diversity
phylogenetic diversity is disproportionately large for marine mammals in the southern ocean
suggests that either species here are less related than elsewhere, or that current species may in fact be poorly known complexes of multiple species, with new species
awaiting discovery
Where are the mammals with the smallest ranges most prevalent?
Land mammals with restricted ranges are concentrated in tropical mountain systems (Andes, Cameroonian, and Ethiopian Highlands) and
on highly diverse islands (e.g., Madagascar, Sri Lanka, and Sulawesi)
Marine restricted-range species are almost entirely found around continental platforms, particularly in the highly productive waters off the Southern Cone of South America
Both associated with highly productive areas subject to strong environmental gradients (altitudinal in land; depth in marine)
Describe the median range size of Land and Marine Mammals
The median range of land mammals tends to be largest where the continents are widest. It is also small where the terrain is topographically complex.
Both of these suggest that the ranges are limited by climate
In marine mammals range sizes are again small around continental platforms where steep environmental gradients exist. However the marine pattern is dominated by a latitudinal effect, with ranges decreasing towards the poles.
This is again likely to be climatically determined (I think)
Where are mammals most threatened?
Of land mammals, the threatened species are concentrated in south & southeast asia. Tropical andes, cameroonian highlands
Threatened marine species are concentrated in the North Atlantic, the North Pacific, and Southeast Asia
All combine high endemism with high human impact
What are the greatest threats to mammals globally?
Where are these threats concentrated?
habitat loss and degradation, and harvesting are the greatest threats to (Land?) mammals globally
For marine mammals the dominant threat is accidental mortality
Maps show number of species affected by:
B=Habitat loss
C=Harvesting
D=Accidental Death
E=Pollution
What percentage of mammals are threatended?
Twenty-five percent of all mammals (data sufficient) are threatened with extinction
over 800 have insufficient data for evaluation
marine species are of particular concern, with an estimated 36% of species threatened
Which mammals are most threatened?
the most threatened families are dominated by large species (extinctions not significantly different from small species)
tend to have lower population densities, slower life histories, and larger home ranges and are more likely to be hunted
Newly described mammals are generally poorly known and disproportionately threatened (349 newly described mammal species since 1992). These factors reinforce the concern that species may be vanishing even before they are known to science.
How much do we/don’t we know
We are still discovering new species (19% increase since 1992)
These are typically in tropical forests which are rapidly disappearing, and are understudied
Marine mammals are less well known (38% data deficient)
A=newly described species
B=Data deficient species
Are there any positive stories?
5% of threatened mammals have stable or increasing populations
