Review:
Subtitled 'demography, genetics and management' this volume
seeks to bring the more standard work of population ecology
into the less predictable world of applied demography in often
small populations. As such it adds to an increasing body of
knowledge which attempts to make the conservation process more
rigorous and successful.
The
aim is to divide the text into three sections loosely based
on the subtitle. Part one is a study of applied population biology
with a focus on wildlife. The second part looks at the population
processes (including genetic variation) which can be used as
a basis for management. The third brings these two together
in a synthesis using actual cases to reinforce key points. Thus
chapter one starts with a great overview of the development
of the human population and the development of other species
particularly in regards to species loss and extinction. Chapter
two forms a very good overview of the scientific method as applied
to wildlife ecology. It covers all key concepts from design
and sampling to errors and analysis. Chapter three turns the
attention to genetics where the reader gets a brief introduction
to the key principles involved as they impact wildlife. This
is especially important as many populations are beneath what
one might regard as the genetic threshold. Chapter four continues
this introductory theme with a look at basic demography. Here
the ground covered is broad with investigations into sampling
techniques and estimations as well as considerations such as
the impact of sex ratios. These four chapters constitute part
one - a brief but very comprehensive overview of the basic components
of wildlife demography. Part two starts with an investigation
into population growth in a most Malthusian way - exponential
and geometric rates of change. Chapter six moves on to density
dependent factors. The aim here is to show that the usual demographic
ideas don't always work due to low population numbers thus introducing
an amount of non-linear responses into the mix. Chapter seven
turns to a more mathematical treatment of population projections
and the factors both theoretical and practical that can cause
the estimations to vary in accuracy. As the author rightly notes,
this is a key area because population numbers is often what
it's all about. As much as we'd like to reduce this, predation
is a fact of ecology whether wildlife or not. The added problem
here is introduced species e.g. feral cats which often disturb
the population dynamics of small species. Chapter 9 brings up
the problem of maintaining (or perhaps reducing the loss of)
genetic diversity. This is no simple matter as the complex world
of zoo breeding records attests. So far the implicit assumption
is of a single population. Chapter 10 breaks this by looking
at the impact of multiple populations including the joining
of small disparate groups of the same species. The aim here
is for connectivity between areas and species but there are
also other factors at play such as human impact. This leads
nicely into chapter 11, the first of part three. Here, the focus
is on human populations and what has happened to the wildlife
with the usual litany of habitat loss, fragmentation, pollution
etc. Chapter 12 turns to the estimation of survival of small
species and what should be done, when. This involves more than
just demography because it also falls into the remit of conservation
management with their own criteria. Chapter 13 moves onto the
more elusive topic of special species - those who can stand
as proxy for a range of species or even ecosystem - think of
the keystone or flagship species. Ironically, this tends away
from the careful line laid down in this book and goes towards
a more pragmatic solution (if all else fails - go for the proxy).
Finally, there's a nod towards conserving species that we also
hunt for food etc.
This
is a very useful text for educators. It covers a large area
succinctly but mentioning all the key ideas at the same time.
This is no mean feat and it makes the book far more useful as
a result. The blend of theory and practice (along with some
guessing) is still a factor in practical conservation and it's
useful to see it being acknowledged. Overall, a very good introduction
to the topic.