Tag Archives: rainforest

How Different is Too Different?

This Peruvian warbling-antbird must walk a fine line between being different enough from its competitors to reproduce successfully, while staying similar enough to be able to recognize and outcompete the same competitors (Image Credit: Hector Bottai, Image Cropped, CC BY-SA 4.0).

Range-wide spatial mapping reveals convergent character displacement
of bird song (2019)
Kirschel et al., Proc B, https://dx.doi.org/10.1098/rspb.2019.0443

The Crux

In nature, many different organisms can be found in a single location, and sometimes those organisms are closely related to one another. When this happens, classical evolutionary theory predicts that these closely related species should differ in some ways, so as to differentiate members of their own species from others and avoid the costs associated with breeding with a mate that will not produce any viable offspring. This is called character displacement, and there are many examples of this in nature where two different species may be very similar when they live in different places (allopatry), but when they live in the same place (sympatry) they will differ in appearance, behavior, or the exact part of the local habitat that they live in (see Niche Partioning below).

A specific form of character displacement, called agonistic character displacement, occurs when traits or behaviors associated with competition differ between closely related species living in the same area. This is thought to reduce the costs of wasting energy on competing with an organism that you don’t really “compete” with. Agonistic character displacement can, however, result in greater similarity of traits when similar species live together, but previous studies in this area have not accounted for other causes of this similarity. Today’s authors wanted to do just that. Read more

Restoring Biodiversity Through Species Interactions

When species like this toucanet are lost, the interactions that they are a part of are lost too. So how can we restore them? (Image Credit: Jairmoreirafotografia, CC BY-SA 4.0)

Estimating interaction credit for trophic rewilding in tropical forests (2018) Marjakangas, E.-L. et al., Philosophical Transactions of the Royal Society of Biology, 373, https://dx.doi/10.1098/rstb.2017.0435

The Crux

We have reviewed more than enough papers on biodiversity loss to entitle us to skip the whole “losing species is bad” spiel (see here, here and here). But what we haven’t talked about is that when some species are lost, specific interactions that those species participate in disappear from an ecosystem. Those interactions range from the minute to the crucial. One such crucial example is that of seed dispersal, whereby specific plants rely on specific animals to disperse their seeds, thus maximising biodiversity in other parts of the forest and creating a positive feedback loop.

Naturally, conservationists will want to reintroduce animals to propagate some of these reactions. But as is always the case in conservation, maximising return is absolutely essential when you’re faced with limited resources and a lot of ground to cover. Today’s authors wanted to develop a system for maximising the effect of species reintroduction.

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