Classics: Mesopredator Release

17 03 2010

© J. Short

Although popularised by Crooks & Soulé (1999), Soulé et al. (1988) first gave us the term that described how entire ecosystems can become unbalanced by a reduction of a higher trophic-level predator exerting so-called ‘top-down’ control on the abundance of species occupying lower trophic levels.

The idea had theoretical support in ecology (Wright et al. 1994; Litvaitis & Villafuerte 1996), but it was not until Soulé and colleagues described how the decline of dominant predators combines with habitat fragmentation to release top-down pressure on smaller predators, thereby increasing predation rates on prey lower down the trophic web.

Crooks & Soulé (1999) described an example where the decline in coyotes (Canis latrans) in combination with urbanisation-driven habitat fragmentation led to an increase in cat (Felis catus) densities and the subsequent decline in scrub-breeding birds. More recent examples attest to the importance of the mesopredator release phenomenon: Myers et al. (2007) described how the decline in large coastal shark species has allowed mesopredator cownose rays (Rhinoptera bonasus) to increase, leading to a reduction in commercially important shellfish densities; and Johnson et al. (2007) showed how dingoes (Canis lupus dingo) in Australia suppress populations of exotic predators such as cats and foxes, leading to more locally abundant populations of native marsupials (see previous post).

Conservation biologists have benefited from this knowledge because we’ve realised that top-order predators affect far more than their immediate prey. These examples really hit home how a fully functional community is required for ecosystem stability, so we should strive to preserve complete complements of communities, not just our favourite species.

CJA Bradshaw

Add to FacebookAdd to DiggAdd to Del.icio.usAdd to StumbleuponAdd to RedditAdd to BlinklistAdd to TwitterAdd to TechnoratiAdd to Yahoo BuzzAdd to Newsvine


Actions

Information

9 responses

10 01 2014
Essential role of carnivores on the wane | ConservationBytes.com

[…] the essential ecosystem functions of these species (see former posts on CB.com here, here and here). The review focuses on the largest and most well-studied species, but the trends likely apply […]

29 07 2013
Fast-lane mesopredators | ConservationBytes.com

[…] which smaller mesopredators become the new top predators of over-exploited communities—keep sprouting everywhere on land and in the water2. Mulling over this state of affairs, it dawned on me one day that understanding how antipredator […]

19 02 2013
21 11 2012
Essential predators « ConservationBytes.com

[...] the important regulating role of predators in myriad systems. We have written extensively on the mesopredator release concept applied to dingos, sharks and coyotes, but we haven’t really expanded on the broader [...]

6 06 2012
Humans are not Mesopredators? « Little Space Sheep

[...] can read more about “mesopredator release” here and here. And you can read about humans as apex predators [...]

18 05 2012
Can Australia afford the dingo fence? « ConservationBytes.com

[...] when dingoes are abundant, foxes and cats aren’t, and native marsupials are. It’s called the “mesopredator” effect, and highlights the important role of predators in maintaining healthy [...]

26 08 2011
A modest proposal to import a notoriously invasive carnivore to eat all our lambs and native wildlife « economical ecology

[...] of Mr. Fox and the persecution of Australia’s top predator, the dingo, this wily little mesopredator has been implicated in the extinction of around 20 native mammals, and has a habit of predating on [...]

8 09 2010
Student opportunities with Australian Wildlife Conservancy « ConservationBytes.com

[...] removal of foxes in Western Australian forests may have led to mesopredator release of cats, and thus an increase in predation pressure on a suite of native fauna. This process may [...]

18 04 2010
The spillover effect « ConservationBytes.com

[...] of maintaining top predators in guarding ecosystem health cannot be understated (see previous posts here, here and here); and 2. It’s not just an immediate benefit – entire communities slowly [...]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s




Follow

Get every new post delivered to your Inbox.

Join 6,395 other followers

%d bloggers like this: