23 August 2011

Blue hotels: nestsite location in Little Penguins

Little Penguins (or Blue Penguins, Korora, Eudyptula minor or even, in Australia, Fairy Penguins) are the most common penguin to be found in New Zealand. They have numerous colonies ranging from a few nest to several thousands and they are found all around our shorelines.Despite being the most numerous penguin species in the New Zealand region there are concerns about population decline throughout the range. Some areas of New Zealand are of greater concern than others. Little penguins are restricted to colony sites that have easy access to the sea, where there is good soil to build burrows (or small caves) and where the right food is found in inshore waters.
One area of New Zealand that has been little studied for Little penguins is along the west coast of the South Island. Many colonies along this coastline are threatened with encroaching development by humans as well as a increasingly busy coastal highway. A recent study by Lincoln University researchers Jasmine Braidwood and Kerry-Jayne Wilson along with Janine Kunz (Georg-August University)examined which features of the habitat were important for burrow use and breeding success along the West Coast.

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Braidwood, as part of her Master of International Nature Conservation, collected data from 167 burrows and artificial nest boxes spread through five colonies in the Buller region as well as 110 burrows across three colonies in South Westland, over three years. Information on numbers of eggs, chicks and adults seen was recorded as well as distance from the high-tide line, track/road and edge of scrub, vegetation type, and terrain.

Over the two years, Little penguins were found in 1/3 to 1/4 of all burrows available, and breeding success increased over the period and was broadly similar to other parts of New Zealand. Most colonies were found in regenerating coastal forests and most burrows were with 25m of the sea. Of most interest was the lack of obvious impact of human activity on breeding success which gives some optimism for the future. The authors worked closely with the West Coast Blue Penguin Trust and hope that this study will provide information for improving the placement of nest boxes in Little penguin colonies in the future to best ensure good breeding success.



12 August 2011

Strewth! Australasian insect conference at Lincoln


The third combined Australian and New Zealand Entomological Societies conference will be held at Lincoln University from 28th August to 1st September. The theme of the conference is "The Status of Australasian Entomology: Where the bloody hell are we?". Currently, about 200 lovers of all things insecty (and honorary insects like spiders) are set to swarm on Lincoln. Participants will hear from keynote speakers Peter Cranston (What can insects, especially Chironomidae, tell us about austral ecological and biogeographical history?), Georgina Langdale (The economics of nature- findings from the TEEB study), Mark Burgman (Making the most of intelligence information and expert judgements for biosecurity), and Andy Suarez (The biogeography of ant invasions and its implications for biosecurity). Plenary speakers feature Steve Goldson, Steven Chown and Robert Hoare.


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There are several themed sessions including:
Australia: Mothership or sistership th the New Zealand invertebrate fauna
Strategic trans-Tasman collaborations enhance arable and vegetable IPM in Australia and New Zealand
Biological control of athropods
Biodiversity and ecosystem services
Communication in a digital age
Climate change and insects
Community ecology
Conference organiser John Marris (Lincoln University Research Museum) promises an informative and fun time with lashings of 3 Boys beer and Wither Hills wine!


10 August 2011

A fine pine: Kakapo not picky about their diet

This article was prepared by postgraduate student Ana Baral as part of the ECOL 608 Research Methods in Ecology course. This marks the last of this year's cohort. Thanks to the class!

Kakapo are found only in New Zealand where these magnificent green parrots struggle for their survival. Only a few of these large birds survive in their natural habitats and are listed as a critically endangered species. Kakapo are unusual parrots in that they become active at night, cannot fly and forage on plants. These birds are ‘treasures’ of New Zealand.

Kakapo are vulnerable to introduced mammalian predators. By the mid 20th century, only a few Kakapo were fighting for existence in Fiordland and Stewart Island. Between 1970 and 1990, all known Kakapo were moved to predator free islands. One such island was Maud Island, in the Marlborough Sounds, because it was free from feral sheep and goats as well as mammalian predators of the Kakapo. The natural forest of Maud Island, now a scientific reserve of 309 ha, was highly modified to pasture and farmlands in the late 1800s. The island was brought back into the conservation estate in 1972 and restoration began. Nine birds were taken to Maud Island between 1974 and 1981.


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Fruiting species, including gooseberries, blackcurrants, guava and apple, were planted in 1975 to provide additional food for Kakapo. Since 1990, Kakapo have been provided with protein rich supplementary food , which includes apple, kumara (sweet potato), and the kernels of almonds, brazil nuts, sunflower seeds and walnuts, to induce breeding artificially.

In an effort to better understand Kakapo, Julie Walsh and Kerry-Jayne Wilson of Lincoln University and Graeme Elliott of Department of Conservation, New Zealand carried out research about home range size and habitat selection of Kakapo on Maud Island. At the time, there were 18 Kakapo on the island; four adult males, nine adult females and five juveniles.
All kakapo were fitted with small backpack radio-transmitters and the positions of birds were obtained at night for almost a year. They estimated seasonal home range size which varied from 1.8 to 145 ha. The home range was smallest in winter and the size varied individually in the use of habitats and plant species.
As a result of conservation initiatives, previously cleared and converted natural forest to pasture was changed to regenerating scrub of eight vegetation types. Nearly all Kakapo used the pine plantation in summer because they fed on pine needles, barks and young cones. Kakapo rarely roosted in the pines because pine has relatively open forest floor of the plantation, and the straight, often branchless, tree trunks. The Kakapo used the treeland scrub in the autumn because they were feeding on five-finger berries. The Kakapo avoided lowland scrub in all seasons and other vegetation types seasonally.

The researchers concluded that Kakapo were more that capable of surviving on highly modified Maud Island. However, despite supplementary feeding, the Kakapo have only bred on the island once. The lack of successful reproduction suggests that Maud Island’s vegetation does not provide sufficient high quality food to trigger or support breeding, though it is more than adequate to support non-breeding birds.



07 August 2011

Fly my pretties

This article was prepared by postgraduate student Nick MacDonald as part of the ECOL 608 Research Methods in Ecology course.
For those of you who have ever ventured beyond the boundaries of buildings and urban assemblages you would at some stage be greeted by one of Mother Nature’s miracles of aviation. I am referring to the New Zealand Hover fly (Melanostoma fasciatum) which can often be seen hovering, acrobating and nectaring at flowers around New Zealand’s natural environments. So what are these busy little creatures? What are they doing and where do they go?

Hoverflies are members of the insect family Syrphidae. They can vary in appearance depending on species and despite their black and yellow striped mimicry of wasps, are harmless and share a unique relationship with humans. Gardeners consider themselves lucky when they are blessed with the presence of hoverflies. This is because at a larval stage, they are predators and prey upon pest insects such as caterpillars, aphids and other small insects. When larvae get close to prey they strike grabbing hold of them with their mouths and suck them dry. Adult hoverflies are herbivorous feeding on the nectar from grass species and Dandelions. They are also expert fliers hovering, manoeuvring and in some cases walking from flower to flower collecting pollen. They are considered to be, along with bees, an important pollinator of New Zealand’s flowers.


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Field boundaries such as hedgerows and fence lines can impede hoverflies ability to pollinate. In a 2003 study, Field Boundaries as Barriers to Movement of Hover Flies(Diptra: Syphidae) in Cultivated Land by Wratten et al, the extent to which field barriers impeded hoverfly movements was analysed. The study used four types of field boundary with varying permeability in each replicate. The boundary types were: post and wire fences, poplars with gaps and dense poplars. Lacy Phacelia or Phacelia tanacetifolia, a plant with nectar rich flowers, was planted on one side of the four boundary types. Five yellow traps were placed on either side of the Phacelia, this provided a trap line on either side of each boundary. Hoverflies found in traps with Phacelia pollen in their guts were collected and counted. This enabled scientists to see if the permeability of a boundary would impede hoverfly flight movements between the Phacelia in each replicate.

Results showed that the type of boundary does have an effect. Less permeable boundaries, for example, the dense poplars had the lowest proportion of hoverflies in traps, post and fence boundaries had the highest proportion and poplars with gaps were in between. The ability of hoverflies to fly through boundaries and pollinate flower is directly influenced by the permeability of boundaries. Other studies such as: Interacting effects of landscape context and habitat quality on flower visiting insects in agricultural landscapes by David Kleijn and Frank van Langevelde, 2006, point to the importance of landscape context for hoverflies; the abundance and richness of hoverflies depends upon the quality of the habitat patches.
So, what does this mean for hoverflies and for us if we continue to erect impermeable boundaries? It would not be a stretch of the imagination to conclude, that there could be environmental implications for New Zealand. If we reduce hoverflies ability to gather food this could reduce their population numbers and lead to a decline in the pollination of New Zealand’s flowers. It could also, diminish larvae numbers and dilute their role as a bio-control mechanism. This could increase the need and use of pesticides and insecticides on our foods. Plants have evolved in conjunction with hoverflies and are dependent on this complex relationship. I suggest that we adopt a mindset that takes permeability of field boundaries into consideration. We could erect boundaries that work with hoverflies, not against them. After all they are here to help.

03 August 2011

Butterflies and wine: friends or foes?

This article was prepared by postgraduate student Hannah Lewis as part of the ECOL 608 Research Methods in Ecology course.
Most of us enjoy the sight of a butterfly flitting around our backyard, however many of us will not be aware of the importance of native butterflies in agricultural ecosystems and the plight that they are facing. Could you name even 3 types of native New Zealand butterflies? The monarch butterfly which is native to North America seems to be the most well known representative of butterfly species within New Zealand.

The intensification of modern agriculture has resulted in an increase in food production to meet the requirements of a growing worldwide population. The amount of cereals (wheat, barley, oats etc) coming off an area of land has increased from 3800 kg/ha in 1968 to 8000 kg/ha 2008. A major issue with intensification has been the reduction of suitable habitat for butterflies and other insect species and the development of plant monocultures. Monoculture (photo 1) is the continuous planting of the same crop over a large area. Doing this greatly decreases the amount of places that are suitable for insects and butterflies to nest/lay eggs and live in. Insects are our main plant pollinators, without this essential function that they provide us for free, there would be no food to feed the world.


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Mark Gillespie of Lincoln University studied his PhD on the prevalence of butterflies in vineyards in the Waipara region, North Canterbury. The intensification of agriculture is one of the main drivers behind biodiversity loss. The introduction of agrochemicals and the creation of homogenous fields (monocultures) without hedgerows or shelter belts have modified natural habitats which have become unproductive for no other use than intensive agriculture and food production.

The analysis of six different vineyards partaking in the Greening Waipara project (see link 2 for more detail) showed that the endemic common copper (Lycaena salustius) (photo 2) and endemic southern blue (Zizina oxleyi) (photo 3) were the most prevalent native butterfly species. Mark measured butterfly density by doing The results show that it is important to maintain remnant vegetation sites for butterflies to inhabit near cropping areas as these are not influenced by farm machinery and agrochemicals.

Mark’s thesis results showed that the Greening Waipara plantings were of least importance to butterflies although this could be because they are so young. Having only been planted within the past 7 years, the plantings are also fairly isolated from other bigger patches of favourable living conditions. Basically, butterflies require a very diverse conservation area to sustain a population including differences in vegetation and the landscape.
To increase the population of butterflies in their vineyard, landowners need to see economic benefits to them being there. Aside from their general conservation value, native butterflies have aesthetic and economic effects on tourism and marketing. Making them good money earners for the landowner, particularly in wineries where tourists will stop and visit and spend some time outdoors. Currently, the vineyards in the Waipara Region are poor habitats for native New Zealand butterflies. Butterflies are commonly used as an indicator species of a particular environment, that is the presence or absence of butterflies native or otherwise can indicate the state of the environment that is being searched. Hence an increase in native butterflies can indicate a healthier environment which is better for the sustainability of monocultures in New Zealand.