It’s not a new topic and in fact it is one that I recently discussed in “A Silent Mass Extinction”.  I also doubt that I’m treading on novel ground by incorporating spiders, centipedes, insects, invertebrates, bugs, or whatever you prefer to use as an everyday descriptive term, in my definition of wildlife.  I guess to make things simple, wildlife is the Animal Kingdom no matter the taxa; at least as far as I’m concerned when picking appropriate subjects for this blog. 

So why the disclaimer?  Well, in the throes of a rather innocuous business conference call my mind was wandering through the sphere of scientific publications and I discovered yet another report that highlighted the lack of attention given to our invertebrate brethren.  Which as I have stated before is both surprising since insects are the majority  of animal species (estimated between 2.5 and 10 million species) and not surprising because of their overall deficiency in the cuteness factor.  As opposed to repeating  the number of insects in jeopardy of extinction, the researchers explored a unique approach that involved…crayons.

We have all heard the songs, quips, and philosophies that tell us children are tomorrow’s leaders, our hope for conservation, our future, and our world.   And all of that is based on the fact that childhood experiences can influence lifelong perceptions.

“Children’s perceptions of animals and the natural environment can be diverse, although their ideas are based around isolated facts and misconceptions are common.  Forest habitats and definitions of the environment are usually characterized as wild places and a habitat for animals.”

“Familiarity and aesthetics are important factors governing children’s connections with animals, exemplified by the popularity of mammals and birds. Of all animals, invertebrates are least understood…”

“Despite children’s awareness of rainforest biodiversity, several taxa, particularly social insects, insects and annelids, are still under-represented compared to their contribution to rainforest biomass and global biodiversity. Such a finding supports previous studies, and may be driven by a variety of factors. Two likely explanations for this are that children are more aware of larger taxa or that children prefer larger taxa. An additional factor in the latter point could be that children drew larger taxa because they felt that this would give them a better chance of winning the competition (perhaps because they deem them to be prettier). Either of these explanations reveals that children’s perceptions focus on mammals and birds and undervalues the true importance of invertebrates.”

The proportion of different rainforest fauna divided by taxa drawn by different age-classes of primary children.

Snaddon, J., Turner, E., & Foster, W. (2008). Children’s Perceptions of Rainforest Biodiversity: Which Animals Have the Lion’s Share of Environmental Awareness? PLoS ONE, 3 (7) DOI: 10.1371/journal.pone.0002579

Who cares about insects? Aren’t they just agricultural pests, household nuisances, and harborers of disease?  I surely hope that is simply an attempt at exaggeration or at best an antiquated notion.  Insects are vital to ecosystem management and fill important environmental roles as pollinators, decomposers parasites, herbivores, predators, and prey.  Additionally, as approximately 50% of insects are herbivorous they aid in supporting higher food chain levels and accelerate carbon and nitrogen cycles. Yet, the potential for multi-species extinction gets little press in the shadows of the cute and cuddly.  And I’m not pointing any fingers because this is just a matter of fact and I’m guilty of it as well.

“In fact, in the last 600 years, the extinction of only 70 insect species has been recorded, a strikingly low  figure compared with the number of recorded extinctions for vertebrates.”

So when I happened upon a publication foretelling of rampant insect doom as a result of (you guessed it) habitat loss, I just had to spread it around.  In this particular study the author focused efforts on monophagous insects, which are those that depend on a single plant species for survival, in 34 biodiversity hotspots.  These worldwide hotspots  have been identified as conservation priorities, have at least 1500 endemic plant species, and have been the victim of habitat loss resulting in the disappearance of 70% or more of its original vegetation.  Because monophagous insects rely on a single plant species, they are most vulnerable to the effects of habitat degradation and loss.  The hotspots contain over 150,000 endemic plants and it is estimated that they support between 5.3 and 10.7 monophagous insect species per plant species.

“Monophagous insects are particularly susceptible to habitat loss because to survive without their hosts they would need to exhibit improbable evolutionary host shifts.”

If we are to assume that the insects will be unable to undergo an “improbable evolutionary host shift” ahead of the pace of plant and habitat loss currently exhibited in the hotspots, then extinction of these resources will be inevitable. And that is precisely what the author found after applying a species–area relationship (SAR) model, which is and has been used to predict decreases in species diversity with reductions in the geographic area of plants.

And the outcome of all that data, described as conservative results, is a total of 213,830 insects in danger of extinction if trends continue.

“The estimated range of 213,830–547,500 species extinctions is three to four orders of magnitude higher than the 70 insect species known to have become extinct globally in modern times, despite the fact that the model was intentionally fed with very conservative parameters. On average my results showed that one monophagous species became extinct when 37–94 square kilometers of habitat was lost.”

It’s so easy to forget that there is more to habitat loss than the disappearance of high profile mammals and birds, but an array of plants and hundreds of thousands of insect species we desperately need.

FONSECA, C. (2009). The Silent Mass Extinction of Insect Herbivores in Biodiversity Hotspots Conservation Biology DOI: 10.1111/j.1523-1739.2009.01327.x

Just happened to do some browsing over at Wild Light (http://www.bugdreams.com)  and came across some incredibly photogenic  insects that got the wheels turning.  At first I was wondering if we have forgotten about this heavily weighted class of biomass, but then I realized a few buzzing pollinators have occupied the headlines over the past few years in regards to declining numbers…you know the story.  And their [insects] importance to a fully functioning ecosystem is utterly undeniable so here’s the spin.

As populations continue to cross the globe with non-native animals and plants in tow we have indirectly introduced foreign invaders and under the guise of agro-science, for instance, have unleashed directly a host of other exoskeleton intruders throughout the past.  But remember the native insects; those evolutionarily adapted to certain habitats and prey and kept in balance by predators?

As native plants are ousted by competitive invasive species, it is not only the birds and mammals that have to contend with a changing habitat but those so-called pesky insects we are always trying to avoid. So what effect does encroaching invasive plants have on insect abundance, and the food web?  Against my initial best guess, according to researchers at the University of Bristol, oddly enough insect abundance was not driven lower with the decline of native plant species.  However, a happy ending it was not as biodiversity suffered greatly.

In one study, larger, specialized, native and more diverse insect species were replaced by smaller invasive generalists that effectively balanced out the biomass load. This change in biodiversity limited the range of species available for predators, and introduced seasonal shifts.  Thus, predators that relied on a once predicted insect emergence were unable to find food at pivotal times such as the breeding season.  It is not just about quantity but quality when it comes to insects, at least as seen by birds, bats, and all the other creatures that depend on this class for sustenance.

As per Ruben Heleno, University of Bristol, “Given that all insects are not equally useful as prey, insect biodiversity is likely to provide a more meaningful picture of the impact of alien plants on higher trophic levels.”

The ripple effect from plant to insect to animal travels the food web and can ultimately create an ecosystem-wide transformation from which we, and especially native wildlife, cannot recover .  By the way, besides changing insect dynamics, increasing non-native plants can also result in the introduction of different seed patterns that may or may not coincide with the lifecycle’s of native wildlife.