@z_w_mcgrath

If you only read the title of this post, you may have thought it was referring to the green men from the show X-FILES or maybe you envisioned invasion by human immigrants making Donald Trump pull out his luxurious locks .

However, it is not the extra-terrestrials or human immigrants I am referring to but the invasive species that are costing us billions of dollars, the ones that we have helped cross our borders, the vines, mosquitoes, ants and the like that now thrive in a novel environment.

While we should be concerned about non-native species, we need to remember that some actually contribute positively to the environment and people’s every-day lives. The first example that comes to mind are those non-native species deliberately introduced to control pests to appropriate levels, commonly referred to as biocontrol agents.

The non-native species we should worry about are those that displace our native species, undermine ecological services, negatively affect the economy and threaten human health. It is these species that begin to be recognised as ‘invasive’ (the term for a non-native species causing undesirable effects) by fellow humans.

New Zealand is home to thousands of non-native species. In fact we have hundreds just from one order of insects (see Darren’s blog post).  This is coupled with growing costs of control and mitigation.  The fact is we cannot control all non-native species.  Therefore, management should use a prioritisation approach, such as managing invasive species likely to have the greatest impacts on native biodiversity.

I know what you’re thinking Mr Trump, but we can’t make them pay for their own control and building a wall isn’t going to solve the issues already in the country.

This is why as part of my Masters project I am creating an alternative method to assess the risk of non-native species. It is proposed to be used as a tool for management prioritisation for those species most negatively competing with our native species, as well improving our standards on importing and releasing biocontrol agents into New Zealand.

Zane McGrath is an MSc student in the Centre of Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland. He is supervised by Darren Ward, Graham Walker and Frances MacDonald (Plant and Food Research, Auckland) examining parasitism by exotic species in native environments.

Posted by Theo Van Noort @TVanNoort

I’ve heard this frequently of late, particularly when I tell people I study wasps. It’s a widely held sentiment here in New Zealand, a loathing barely matched by feelings directed towards the infamous possum.

Of course, there is something particularly terrifying about a creature that not only stings repeatedly but can also fly (read: stings to the face, shoulders, knees and toes – no problem). Pair this with a temperament more volatile than a rest-home pumped on prune juice and you can see why wasps might have garnered this reputation.

To clarify, it’s not New Zealand’s assemblage of solitary native wasps causing such affront (read earlier blogs by Tom and Zane), but rather invasive German (Vespula germanica) and common (Vespula vulgaris) wasps. These social wasps build nests and have distinct caste systems dividing the role and function of each individual in the colony.

These two species present an unprecedented problem to New Zealand because they thrive in competition against our “naïve” flora and fauna. Vespula wasps are generalist predators and have great ecological plasticity: they can adapt and change their behaviour to best utilise the resources available in a given environment. Long story short, they decimate invertebrate populations via predation, dominate important carbohydrate resources such as honeydew in beech forest, and probably pose a direct threat to native vertebrates like lizards and birds. Moreover, public health, recreational needs and economically important industries such as horticulture, apiculture and silviculture are also detrimentally affected by Vespula wasps. In dollar-speak: ~$130 million dollars in damage per year. 

Given these traits, it’s easy to understand the enormous need to develop new tools with which to control Vespula wasp populations.

Earlier this week I had the opportunity to attend an open workshop run by the Wasp Tactical Group in Wellington: Tactics and Tools to Reduce the Pain of Pest Wasps in NZ. This workshop brought together scientists and other interest groups from a range of different organisations to collaborate and update the current status and future prospects of Vespula control. Despite the variety of backgrounds within the group, everyone was unified by this desire: to reduce the immense damage caused by Vespula wasps.

Through the day we heard from the different scientists about the range of tools under development by the Bioheritage National Science Challenge  for this very purpose. These control tools include the Trojan female technique, biocontrol using mites, manipulating behaviour using pheromones and semiochemicals, and targeted chemical baits. It also includes a modelling component to understand how these different tools might be used and integrated. Further to this is developing an eradication strategy, perhaps following the tradition of mammalian pest eradications which first targeted small islands.

While acknowledging the hurdles ahead, the floor was optimistic, particularly around the success and public interest to date in Vespex . Vespex, an insecticide developed by Merchento, has proven effective for drastically reducing the abundance of Vespula wasps in areas where it is applied whilst leaving other insects like honeybees unharmed. While Vespex is by no means a silver bullet, if coupled with these other techniques still under-development we may have a good chance at “reducing the pain” of these pest wasps.

Or, in other words, killing the bastards.

Theo Van Noort is an MSc student in the Centre for Biodiversity & Biosecurity, School of Biological Sciences, University of Auckland. He is investigating the attractiveness of different lures to Vespula wasps, as well as their potential role in pollination and seed dispersal. He is supervised by Jacqueline Beggs and Imogen Bassett

Posted by Emma Bodley (Twitter @ebodley)

When you think of an orchid what usually comes to mind are the beautiful showy plants such as the moth orchids that most people have on the dining room table or in the guest bathroom.

A moth orchid, by Orchi – Self-photographed, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3126890

In the research world these are also the same orchids that get all the attention. But the New Zealand orchid diversity is more understated, usually terrestrial green plants blending into the forest floor. As ecologists we know very little about NZ orchids in general and there are many forms that are yet to even be formally named.

Our recently published paper reveals some of the secrets about the

phenology and pollination system of one native greenhood orchid Pterostylis brumalis. What pollinates them? How do their pollinators know where the orchids are? Do they use sexual deception – tricking male pollinators into visiting the flowers like some other orchid species do?

We followed the phenology of this winter-flowering orchid closely, trapped for pollinators using sticky traps and assessed the natural seed set of a population. Problem was, pollination was extremely limited in the two populations we studied. We only collected only one insect, a female fungus gnat, that had interacted with a flower and was carrying pollen. As a consequence, natural fruit-set was low, averaging only 2.6%. In contrast, when we hand-pollinated flowers we achieved 66.7% fruit-set. It remains a mystery as to what naturally pollinates this species.

One of the harder areas to investigate is the theory of sexual deception in greenhoods. Usually orchids that trick male pollinators into visiting their flowers produce a scent that mimics that of a female. We wanted to look for evidence in the flowers that this is a possible mechanism for attracting male pollinators. Studying the colour and micromorpholgy of the flower showed some interesting features. We were looking for scent glands where the scent could be released from. We found some hairs that could perform this function, but most likely guides the pollinators into the centre of the flower down to the pollen. We didn’t find sufficient evidence to prove that sexual deception is really happening in this system. There are still plenty of avenues to research to get a better understanding of orchid pollination.

Bodley, E., Beggs, J., Toft, R., & Gaskett, A. (2016). Flowers, phenology and pollination of the endemic New Zealand greenhood orchid Pterostylis brumalis. NZ J Bot, 1-20.

This research was undertaken while Emma Bodley was an MSc student at the Centre for Biodiversity & Biosecurity, School of Biological Sciences, University of Auckland. She successfully completed her study and is now a Botanical Records and Conservation Specialist at Auckland Botanic Gardens. She was supervised by Anne Gaskett and Jacqueline Beggs.

Posted by Darren Ward @nzhymenoptera

New Zealand is well known for its problems with exotic pests and weeds; whether it’s vertebrate predators and their devastating impacts on native birds, vertebrate herbivores chomping through tonnes of native vegetation per night, or weeds out-competing and smothering native species. Relatively speaking we have excellent information on the number of these exotic species, their distributions, densities, and impacts.

But what about exotic invertebrates? How many are there in New Zealand? Apart from a relatively small number of high profile species, the total number of exotic invertebrates species established here is only a ‘best guess’. However, generating such information is an important part of studying invasion biology, particularly when such information is compared and contrasted with other parts of the world.

Hymenoptera are a massively diverse Order of insects, including bees, ants, wasps, and parasitoids. Humans have a love/hate relationship with Hymenoptera. They can be pollinators of economically important crops and of native plants, and have widespread application as biological control agents for the control of insect pests. However, when they are bad, they are horrid. Invasive ants, social wasps, sawflies, woodwasps, and gall wasps, all cause huge economic, social, and environmental problems in different places around the world.

Asian Paper wasp on nest in Auckland.

 

Recently, we completed the first inventory of all exotic Hymenoptera in New Zealand, and made comparisons to a large European database (DAISIE, Delivering Alien Invasive Species Inventories for Europe).  We found several interesting trends.

• Over 300 species are established in New Zealand, more than in Europe (334 vs 286). The European fauna also had a much higher proportion of intentional releases (i.e. biocontrol, pollination), further highlighting the large number of unintentional establishments for New Zealand.
• Also strikingly was the ‘disharmonic island’ nature of New Zealand. One third of the taxonomic families in New Zealand have no native species, and are only present as exotic representatives, including common taxa such as honeybees, bumblebees (Apidae), and social wasps (Vespidae).
• We also found a change in the origins of exotic species establishing over time, with an increasing dominance of species from Australia during the past 25 years.

Our project shows the importance of examining large-scale datasets of multiple species over long-periods. It also shows the importance of scientific collections – where much of this information was obtained.

Darren Ward is an entomologist in the New Zealand Arthropod Collection at Landcare Research, and a senior lecturer at the School of Biological Sciences, University of Auckland. More detail: Ward DF, Edney-Browne E. 2015. Poles apart: comparing trends of alien Hymenoptera in New Zealand with Europe (DAISIE). Plos One. 10.1371/journal.pone.0132264

 

Posted by Alice Baranyovits @ABaranyovits

Last week the Royal Society of New Zealand launched their report on options for climate change mitigation for New Zealand entitled ‘Transition to a Low-Carbon Economy for New Zealand’. As part of the launch they released several infographics including a panel on what immediate actions individuals can make to reduce their carbon footprint. These included increased use of public transport and cycling, planting trees, using energy efficient appliances and reducing the frequency of air travel. Whilst these are all important and worthwhile actions, I feel that there is one obvious oversight, one big elephant, or more accurately in this case, cow in the room and that’s that there is no mention on this infographic for the need to reduce meat and dairy consumption.

Now in order to be fully transparent…I’ll admit I’m a vegan and as my friends and family will attest, for someone who doesn’t eat any meat or dairy I do seem to spend quite some time talking about it. But while I’ll try to avoid climbing onto the soapbox for this one, I do feel that meat consumption is something that needs to and should be discussed.

New Zealanders it seems, like their meat. NZ is often listed as one of the most carnivorous countries in the world, with annual meat consumption frequently quoted as being greater than 100 kg per person (with one estimate at a super-sized 126 kg), putting it well above the global average of 42 kg per year – according to this chart from the Economist, New Zealanders are the 4^th biggest meat consumers in the world!

Like many other developed countries, New Zealand’s meat consumption has remained fairly steady and is predicted to remain at similar levels for the coming decades. Globally however, it’s a different story. The demand for meat is growing, linked with increasing wealth and urbanisation of many developing countries. This increase in demand combined with rapid human population growth has seen meat production grow from around 70 million tonnes in 1961 to a huge 278 million tonnes in 2009, with further increases up to a whopping 460 million tonnes predicted by 2050. Now that is a lot of meat.

The stated contribution of livestock production to current global greenhouse gas (GHG) emissions varies from around 10 to 25% (depending on whether emissions due to deforestation and land use change associated with pasture creation are included). But the regularly quoted FAO’s statistic of 14.5%, would put livestock production on par with the emissions contributed by the global transport sector. In NZ, agriculture contributors almost half (47% in 2010) of the country’s GHG emissions, 95% of which come from the pastoral system. On top of this, livestock production has various other substantial environmental impacts, such as high water use, groundwater contamination and biodiversity loss (summarised nicely here).

Ways to mitigate these GHGs are often described in two parts; reducing emissions during production (see here for more examples) and reducing demand. The Royal Society’s report contains multiple potential technical options that could be used to help reduce production related emissions, such as increasing farm efficiency, developing methane inhibitors and selectively breeding lower-emission animals.  However, although these technologies may decrease emission intensity, they are unlikely to limit overall emissions if total production continues to grow.

So how about reducing demand? A global shift to a more plant-based diet, much lower in animal protein than the current average diet in developed countries, has been repeatedly suggested by the UN and others, as one practical way to tackle not only GHGs, but other environmental issues associated with human food production (see the end of the post for some links). For example, in their Fifth Assessment Report the IPCC stated that global dietary change could have a substantial impact on agriculture’s GHG emissions, with a potential saving of 0.7-7.3Gt CO₂-eq/yr in 2050. Additionally, a recent study by Springmann et al. (2016) reported that a global move towards a low-meat diet, which limited red meat intake to 300g a week, would reduce the predicted 2050 food-related emissions by 29%. If people went further and shifted to a fully vegetarian or vegan diet then they predicted that the food-related emissions would be decreased by 63 and 70% respectively.

Now I’m certainly not suggesting that everyone goes vegan, I understand and appreciate that there are many people that rely on the meat and dairy industry for their livelihoods, as well as the fact that many people simply enjoy eating burgers, sausages and cheese. But this isn’t about stopping eating meat but rather reducing how much and what type (beef, for example produces more emissions per kg of protein than poultry).

And yes I know that New Zealand exports much of the meat (83% of beef) and dairy (95%) it produces, so a reduction in domestic demand in New Zealand will have less impact than in a country that consumes most of its own meat. However, that doesn’t mean that we shouldn’t act.  Changing your diet isn’t going to ‘solve’ climate change, but it is one of the easiest ways individuals can help reduce their own environmental impact.   It’s time to start talking about the cow in the room.  So, anyone for a veggie burger?

Further Reading:

• Royal Society of New Zealand (2016) Transition to a low-carbon economy for New Zealand
• Food and Agriculture Organization of the United Nations (FAO). Tackling climate change through livestock – A global assessment of emissions and mitigation opportunities.
• Chatham House Report – Livestock – Climate Change’s Forgotten Sector
• Chatham House Report – Changing Climate, Changing Diets: Pathways to Lower Meat Consumption
• UNEP (2010) Assessing the Environmental Impacts of Consumption and Production: Priority Products and Materials
• UNEP (2012) Growing greenhouse gas emissions due to meat production
• Tilman & Clark (2014) Global diets link environmental sustainability and human health
• New Zealand Agricultural Greenhouse Gas Research Centre Factsheet – The Impact of Livestock Agriculture on Climate Change
• The Guardian – UN says eat less meat to curb global warming
• Meat Atlas – Facts and figures about the animals we eat

 

Alice Baranyovits is a PhD student at the Centre of Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland. She is researching the movements of kererū in urban areas. She is supervised by Jacqueline Beggs, Mick Clout, Todd Dennis & George Perry.

Posted by Delayn Fritz @WildOptic

Progress and technological advancement allows us the brilliant capability to receive goods from the other side of the planet in only a matter of days. This is a good thing for the delivery men who just 100 years ago would have had to suffer an arduous journey just for the yearly supply of salt. However, this decrease in vectoring time has meant that survivorship of stowaway critters has increased, as well as an overall increase in the amount of trade volume. In fact, it has been shown that the amount of trade may be the biggest indicator of how many invasive species are established in a given country, and this trade has steadily been increasing.

So this may leave you wondering how do species become invasive, and move from the initial ’transport stage’ and proliferate into an invasive species. A unified framework for this process has been widely accepted and explains several stages from transportation, to establishment, to spread. This is important because between each stage are biological barriers that may inhibit species from moving to the next stage. Species can overcome these barriers, through increased propagule pressure (i.e. the amount of individuals being introduced), by being pre-adapted to the climate of the new environment, and perhaps by possessing certain biological characteristics.

Why should we care about the process and not just focus on eradication? The associated effort and cost to remove a species increases as it occupies more area. The fruit fly incursion responses in 2012 and 2014 both cost around $2 million, and that was just the size of a suburb. The real goal and money saver while getting the best results would be to prevent a species from establishing and/or spreading in the first place, this is best done in conjunction with understanding the invasion pathway and bolstering the natural barriers that already exist.

This is where my MSc project comes in. I am studying a data set spanning 60 years of interception data at the border, and records of spread within New Zealand to try and understand the reasons that non-native ant species have either been successful in establishing and spreading or why they have failed. In starting to really understand how these barriers affect success of species we can improve chances of successful prevention through risk assessment.

 Delayn Fritz is an MSc student in the Centre of Biodiversity  and Biosecurity, School of Biological Sciences, University of Auckland. He is interested in the invasion process of ants (Hymenoptera: Formicidae) in New Zealand. He is supervised by Darren Ward and Eckehard Brockerhoff (Scion, B3).

 

Posted by Ellery McNaughton @EJ_McNaughton

I struggled in achieving the Herculean feat of getting up before dawn today. Fortunately for me, I had help – my local tūī (Prosthemadera novaeseelandiae) decided to serenade the neighbourhood, a sound far more pleasant than the alarm on my phone. Not everyone is so appreciative, especially when the ‘dawn chorus’ begins well before its name would suggest.

Timing of dawn song is influenced by a number of natural factors. For example, studies have shown that rain, noise from nocturnal insects, intensity of moonlight, and even individual personality can advance or delay the onset of dawn song. Of course, factors such as noise and light intensity can also be introduced into the environment as a result of human impact and urbanisation.

The onset of dawn song has been found to be much earlier for urban birds than for their rural counterparts, a difference attributable to traffic noise and artificial light at night (ALAN).

Urban birds have been found to sing earlier in the morning when exposed to traffic noise. And it’s not just road vehicles – birds near airports also advance their singing to avoid peak aircraft traffic in the morning. ALAN has also been linked to advancing morning bird song. There are many sources of urban ALAN, but a large proportion comes from streetlights. The effects of different types of streetlights on the timing of urban bird song is not yet fully understood, although there have been some indications that different technologies can have varying effects on different species.

This is the area that I’m interested in for my research. I hope to determine whether changing the streetlights from orange (high-pressure sodium) lights to white (light emitting diode) lights makes my local alarm clock start serenading earlier or later in the morning. Coincidentally, I am also forever grateful to the inventors of audio recorders for enabling bleary-eyed ecologists to sleep through their data collection.

Ellery McNaughton is a PhD student in the Centre of Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland. Her project will investigate the effects of a city-wide changeover in streetlight technology on urban bird behaviour and ecosystem function. She is supervised by Margaret Stanley, Jacqueline Beggs, Kevin Gaston(University of Exeter, UK) and Darryl Jones (Griffith University, Australia).