Mar Cabeza

2 Responses

1. Astrid van Teeffelen Says:
   August 6th, 2007 at 7:20 am

   Do we seek the horse or the cart?

   Sergio commented to Nature, that “you cannot put the cart before the horse”, meaning that we cannot look at the application (conservation planning), before knowing the biology (relationship between predators and biodiversity) see http://www.nature.com/news/2007/070730/full/070730-10.html

   Conservation planning is a crisis discipline: There is much biodiversity in threat, and there is little budget available for protecting it. Therefore, we need to search for ways how to spend this budget as effectively as possible. It is impossible to find data on the full range of biodiversity. We therefore need to rely on sets of species or environmental variables, that help us identify which sets of sites are best to protect, to cover the range of species present in the area. Such sets of species or environmental variables are called surrogates. Efficient surrogates find the minimum number of sites needed to represent all species. Finding such surrogates is an important challenge.

   Sergio et al aimed to test if raptors could be such surrogates in the Italian Alps. They found that raptors indicate species richness, but did not test if raptors are efficient surrogates - unique assemblages of species may not occur in sites with greatest species richness. If cost-effective conservation planning is the cart, we need to look for the best horse (efficient surrogates) to pull it. Sergio et al seem to turn it around: they have a horse (raptors) and seek for carts which it can pull. Thusfar it has not been proven that it can pull the cart of cost-effective conservation planning.

2. Anni Arponen Says:
   September 2nd, 2007 at 12:46 pm

   A cart to pull for top predators?

   As Mar already pointed out, top level predators in general are very unlikely to be effective biodiversity surrogates due to their biological characteristics. Instead, use of top predators as flagship species has been quite a popular idea: Much of conservation funds are collected appealing to the public and decision-makers for the protection of some specific charismatic species. And there is no denying that top predators, or any cute and furry animals, can be very effective in fundraising. But this has nothing to do with being a good surrogate for biodiversity, and even less so for complementarity, which is what would be needed for systematic conservation planning.

   Rather than trying to find connections between top predator occurrences and biodiversity to justify use of top-predators as biodiversity surrogates, which appear not to exist, a more fruitful approach (to find a cart for the horse to pull) could be to look into the economic side of the story. It might even turn out that the amount of biodiversity being protected with funds gathered with the help of charismatic species, even though not optimally allocated, may protect more biodiversity altogether than optimal use of scarcer funds that could have been obtained without flagship species. It would be very interesting indeed to find out whether it is better to get more money, more protected areas, but in the “wrong” places, or less funds that are allocated optimally to maximize biodiversity protected.)