Honey, I Shrunk Biodiversity


The race against species extinction has started, and ecological modelling of species impacted by the catastrophe that is human civilisation is an essential tool in prioritising conservation efforts.

A recently published study by the University of Southampton researchers has highlighted that human-made threats such as climate change, habitat destruction, industrialised farming and intensive hunting caused extinction patterns which are far from random. While large, slow-lived animals such as larger mammals and birds are the first ones on the “doom” list, smaller organisms adapted to a wider range of habitats, with high reproductive rates and a diet of insects, are expected to come out victorious in the survival game. Emblematic species such as tigers and rhinos are thus expected to be replaced by rodents and small, sparrow-sized birds like the White-browed Sparrow-weaver (see featured image) on biodiversity posters in future decades.

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Such a shift in biodiversity structure is problematic. The importance of preserving the diversity of ecological more than individual species has been pressed on by many studies in recent years, and “downsizing” species worldwide puts many functions in jeopardy. Ecological functions are roles that species play in ecosystems, and the higher diversity of functions in an ecosystem, the more resilient to challenges the ecosystem will be. As a consequence, a selection for smaller organisms is likely to drive biodiversity further into a vicious circle in which ecosystems will be more sensitive to disturbance and more selective pressures will apply. The smaller it becomes, the smaller it might get, until ecosystems become completely unrecognisable.

Species possess particular traits, or characteristics, an ensemble of skills which, like on a résumé, make them fit to carry out a specific ecosystem function. Environmental quality defines which traits will survive, and by performing their respective “jobs”, species also shape the environment. As a consequence, biodiversity ultimately shapes our own habitat. If non-random loss of biodiversity causes the loss of most currently existing ecological functions on this planet, humankind is not expected to last very long either.

A glimmer of hope persists: these results are based on predictions, not facts. As long as ecological modelling experiments and studies similar to that published by the University of Southampton’s Robert Cooke and Felix Eigenbrod and Amanda Bates from Memorial University, Canada, receive funding and support, scientists may be able to forecast potentially dramatic consequences of human activities. This, in turn, could lead to action on policy-making and influence conservation efforts. This is a theme picked up on by Amanda Bates:

As long as a species that is projected to become extinct persists, there is time for conservation action and we hope research such as ours can help guide this.

Therefore, rather than being a source of despair and helplessness, this branch of biological sciences is aiming to raise awareness on the urgency of conservation efforts, while hinting at which species and habitats to prioritise. After all, a starting point is often what communities need to take environmental action.


Science and Tech editor 2019/20, Fourth year Marine Biology student. Can be found at the pool, the sea or on a windsurf board.

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