The best scientific method (Bayesian form of H-D)

Andya,I don't think you're off base here. As you said, determining the ecological impact of a given species is very difficult. However, a trophic cascade leading to severe ecosystem disruption usually begins at either the bottom or the top of the energy web in a community. Birds normally don't fall into this category. Extinction of avian populations CAN have secondary effects (I'm thinking of the extinction of the lowland populations of Hawaiian honeycreepers via avian malaria leading to the extinction of five endemic species of Hibiscadelphus - in this case the plants and birds had a tight mutualistic relationship). In general, there are enough other members of the particular species' guilds to "pick up the slack" when one or another population disappears.Birds are more often the secondary or tertiary victims of the elimination of one end or the other. One example is the extinction of numerous avian species populations on Barro Colorado Island (Lake Gatun, Panama) as a tertiary effect of the extinction of the local populations of Puma concolor and Panthera onca. The elimination of these top predators led to a population explosion in ground foraging "mid-level" mammals like the collared peccary (Tayassu tajaca) and coatimundis (Nasua narica). The explosion was devastating for ground nesting birds like the great currassow (Cax rubra), the marbled wood-quail (Odontophorus gujanensis), the rufous vented ground cuckoo (Neomorphus geoffroyi), and the black faced antthrush (Formicarius analis), all of which are now extinct on the island.IOW, you're right - the extinction of Indonesia's endemic rhinos will likely have a larger and more profound effect on the ecosystem than the elimination of a few bird species.

Ya know, Stephen, I agree with most of what you wrote in this post. Being mathematically challenged as I am (I subscribe to an aphorism that one of my ecology professors often used 25 years ago: "For an ecologist, life is too short to understand calculus."), I find it difficult to follow a lot of the deep mathematical theory used today in ecology. I keep waiting for the simpler math models that will explain the data and allow predictions. OTOH, in our field we have to give tremendous credit to MacArthur and Wilson for providing the math that turned the science of ecology from a pure descriptive science to one with a solid theoretical foundation. Even if I can't follow all the math in their seminal book, "Theory of Island Biogeography" (which contains more abstruse mathematics than some physics texts), I can see how they made their predictions, and how the predictions have in many cases been borne out. The Equilibrium Theory may (as others have maintained) be incomplete, but it was a damn sight better than anything that had come before.I think that anyone that can come up with a simpler way of expressing ecological theory in mathematical terms that does what ETIB did would be able to write their own ticket in the field.

Yeah, I've seen the weathervane blowing back and forth, and noted especially your very strong arguments against what Stephen has put forth. In my defense, I tend to agree with the post to which I replied. And in fact Stephen (assuming he's the Fretwell he claims to be) was at one time a very promising scientist. His book, "Population in a Seasonal Environment", is an early "touchstone" in modern ecology. So he was a scientist at one point.In spite of his insults to me - based on which I have developed a marked distaste for continuing any discussion of HD or his other outre beliefs - there is a possibility that I might learn something from him if he can be engaged in the one area where he has proven credentials.Think of it as an opportunity to discuss gravity with Newton. After all, following publishing "Principia", Newton wasted the entire rest of his life writing execrable biblical exegeses on the book of Daniel. Just 'cause a scientist was brilliant in the beginning doesn't make the latter part of his life necessarily either illuminating or even rational...