Drones and overpopulation of a reintroduced species

*Matthew: Conservation and restoration efforts may attempt to right the wrongs of past generations, but can this result in too much of a good thing?

The creation of fenced feral-free reserves has successfully seen the reintroduction of several locally extinct and endangered animals. Yet, we poorly understand the consequences of faunal repatriation for enclosed ecosystems. Current ground-based surveys are expensive, time consuming and labour intensive.

Arid Recovery Reserve is located within the vast arid lands of northern South Australia. There are concerns surrounding overpopulation of the reintroduced burrowing bettong (Bettongia lesueur) and sustainability of this enclosed ecosystem. Affordable, practical, and repeatable monitoring methods therefore need to be developed.

My honours project aimed to assess the ability of unmanned aircraft (drones) to monitor both the vegetation and population of B. lesueur within Arid Recovery Reserve.

Quantitative assessment of vegetation assemblages and warrens (burrows) through both ground and drone based surveys were used to assess differences among two feral-free enclosures and one area outside the reserve. This information is beginning to provide reasoning behind observed differences in the vegetation within and among the three sites. Providing an initial assessment of drone use for monitoring vegetation and B. lesueur populations, this research has applications both within and beyond Arid Recovery Reserve.

With implications for how we sample and survey ecosystems, initial results may open the doors to a seemingly endless room of future research.

*Today’s guest post is from Matthew J. Bowie (aka Bowie). Here’s a bit more about him:

Why am I interested in science communication? I think I have always been the type of person that simply enjoys talking to other people about what they do, and this extends to their science. I somewhat stumbled across the field of SciComms this year, and after randomly emailing a now fellow communicator the question “what is science communications?…I think I might be interested in it”, I was hooked. I am now finalising my honours degree in Environmental Science at the University of Adelaide, helping out on the South Australian branch of Australian Science Communicators, and will soon start writing for RiAus. The year ahead for me is uncertain, but I am looking forward to a career with strong SciComm components.

To solve a mystery you need evidence

Sarah: Have you heard about the spectacular mass meetings of cuttlefish in the waters of the Spencer Gulf, South Australia?

Every year between May and August these incredible cephalopods (in the same family as squid and octopus) arrive to mate and lay eggs in the rocky reefs near Port Lowly. Recently fewer and fewer cuttlefish have been arriving to mate – scientists don’t know if this results from a natural cycle in their abundance, or something more ominous.

Recently I wrote a piece for The Lead SA about new ways of identifying different species and subspecies of cuttlefish, and plans to create a better evidence base for keeping an eye on them into the future (image thanks to southoz on flickr].

New science helps track mysterious cuttlefish

The annual migration of cuttlefish into the Spencer Gulf of South Australia has begun but scientists are baffled by the lack of cuttlefish in the usual spawning grounds.

Massive declines in the cephalopods have led scientists to look for ingenious ways to track the sea creatures.

Scientists are using parasite tracking amongst a panel of other biological tools to identify discrete populations of the Great Australian Cuttlefish (Sepia apama) in the waters around South Australia.

The work offers a rare insight into how species evolve over time, and provides vital information for natural resource management.

“There are likely to be five subpopulations of Great Australian Cuttlefish across the species range,” said Bronwyn Gillanders, Professor in aquatic ecology at The University of Adelaide.

Monitoring the parasites that live on cuttlefish could be the most useful tool for identifying the different populations. Recent PhD graduate Dr Sarah Catalano performed research focusing on an unusual worm-like parasite that is only found in cuttlefish and other cephalopods. Each species of cuttlefish is though to host its own genetically unique parasite.

“Parasite genetics might be a more sensitive tool than looking at the cuttlefish themselves to distinguish whether different species or subspecies actually do exist,” said Professor Gillanders.

Another line of research to identify cuttlefish subpopulations focuses on the appearance of their unique beaked mouth – used by cephalopods to masticate their food before swallowing – and related dietary preferences.

Professor Gillanders and her colleagues hope that by using multiple lines of evidence – parasite genetics in combination with cuttlefish genetics and cuttlefish dietary preferences – they will be able to sort out whether the different groups of cuttlefish in the waters off South Australia are separate species or subspecies.

In particular, they’d like to determine whether the spectacular breeding aggregations of Great Australian Cuttlefish that occur annually during May-August in the northern Spencer Gulf are confined to a particular subpopulation.

Although historically up to tens of thousands of cuttlefish have arrived in this period to breed, that’s not been the case recently.

“The numbers have been decreasing over many years – since the peak in abundance since the late 1990s, they’ve dropped in number by about 90%,” Gillanders said.

Although recent low numbers of cuttlefish have been attributed to many factors – including natural cycles in cuttlefish abundance or changing environmental factors – it’s hard to know the real reason without the existence of long-term evidence.

This level of ambiguity is something Bronwyn is keen to avoid in the future. Along with colleagues across the sciences, governments and industry, she is running the Spencer Gulf Ecosystem and Development Initiative . The program is one of the first of its kind in the world, aiming to provide all stakeholders with access to independent and credible information about the Spencer Gulf and opportunities to develop it without compromising its environment.

 

Phase 2 starting in 3, 2, 1…blast off

OK, so I promised that ScienceforLife.365 would transition to phase 2 beyond National Science Week 2013.

First, I need to tell you about the most fabulous celebratory #BrainBreak Morning Tea I hosted to celebrate my year of daily blog posts.

A group of scientists, writers, communicators, colleagues, friends and family members joined me on August 14th to eat yummy cakes, drink tea and champagne and chew the fat about science and life. Photos from the day are shown below.

I was also delighted to receive a letter from  Tom Kenyon (SA Minister for Manufacturing, Innovation and Trade) and Grace Portolesi (SA Minister for Science and Information Economy) to mark this milestone.

The letter read as follows (reproduced with the permission of Minister Kenyon):

Dear Dr Keenihan

Congratulations on your blog Science for Life.365 which has celebrated science every day of the past year.

As the Minister for Science and Information Economy and the Minister for Manufacturing, Innovation and Trade, we both appreciate the significant contribution that South Australian scientists make to our community and our everyday lives.

In particular, we admire your year-long commitment to sharing with others how your daily life is shaped by your education in, and love of, science. We also applaud you efforts in encouraging an interest in science among the general public – particularly encouraging younger people to become fascinated by the world we live in.

As you know, the South Australian government seeks to raise the research and innovation profile of South Australia while at the same time encouraging a broader understanding within our community of the importance of science in our daily lives. We would like to recognise your efforts and your dedication to writing about science and thank you for your efforts.

Yours sincerely

Grace Portolesi and Tom Kenyon

I’m very grateful for the Ministers’ acknowledgement and everyone’s support, so thank-you.

Day 290. Local and global

This week UK newspaper the Guardian launched its Australia edition.

The ‘paper’ is independent, digital and free.

Perhaps a reflection of its new expanded geographical focus, a story on watery deaths along the coastline of South Australia was available via click-throughs on the Environment pages at both the UK and Australia sites this week.

Written by Malcolm Sutton*, Warmer seas could lead to more dolphin deaths in South Australia describes the phenomenon of drastically elevated numbers of dolphin and other marine species carcases washing up on metropolitan and regional SA beaches in recent months.

The deaths are being officially blamed on algal blooms – growth explosions of floating microscopic algae – resulting from a prolonged period of elevated sea water temperatures during March 2013. Other theories include algal blooms due to discharge from the Port Stanvac desalination plant, and viral infection in heat-stressed, immunocompromised dolphins.

No firm answer will be available until autopsies on the dolphin carcasses are completed.

For me, the publication of the story on an international newspaper website shows how stories sourced from little-known places around the world can contribute to a body of evidence. In this case, the story has broad interest due to its connection with other stories on warming of oceans due to climate change (for other examples, see here and here).

*presumably the same Malcolm Sutton as he at Stock Journal

[image thanks to Les Haines on flickr]

Day 241. Maggie

This week has been very exciting for those of us who love stingrays.

What, you don’t know what I’m talking about?

I’ll set the scene a little:

Whenever we head to Yorke Peninsula, I’m constantly scouring the water and beaches for signs and remnants of life.

On the beaches we find cuttle bones, skeletons (both the internal – eg fish – and the outside – eg sea urchins – kind), weeds, shells, eggs, fins, feathers and all manner of other once-living material.

In the ocean we often spot jellyfish, bait fish, salmon, squid, cuttlefish, dolphins, seals and lots and lots of rays. Eagle rays, fiddler rays and big black scary rays, mostly. They terrify and enthral me all at once.

For about 10 years now I’ve had my eyes peeled for the elusive Magpie Fiddler Ray (Trygonorrhina melaleuca), described for the first time in 1954 and not reported since. Because of its rarity, the SA Museum had put the call out about a decade ago for members of the public to report sightings, or indeed produce a living example to help them with classification of the species.

Then yesterday up one popped, in the Port River in outer suburban Adelaide! Back from the dead, right on our doorstep!

Caught alive by members of the Adelaide Game Fishing Club, the ray was immediately passed on to the South Australian Research and Development Group to be described and bothered slightly for collection of tissue samples. The exciting possibility that Maggie – as she is affectionately being referred to – is pregnant is also being explored.

Don’t worry: Maggie will be released after a few weeks.

[image thanks to Acutance on flickr]

Day 176. Monarch

In contrast to the swallowtail, this monarch butterfly – photographed in my garden yesterday – is an introduced species.

Famous for their amazing capacity to migrate over vast distances, monarchs originated in the Americas. They are thought to have arrived in Australia in the early-mid 19th century – perhaps through flight over the Pacific from Hawaii, perhaps introduced.

According to sabutterflies.org.au, monarchs are probably the longest lived of any butterfly, due to their tough wings, durable body, and inedible poisonous properties.  The overwintering generation can live for 8-9 months.

Day 175. Swallowtail

A very busy, stimulating weekend at the ScienceOnlineAdelaide WatchParty has left me so filled with thoughts that yesterday I simply could not condense a single blog post to wrap it all up.

Instead, I retired to my garden to play backyard cricket and take a few photographs.

The image shown above is of a swallowtail butterfly, captured as it flitted from leaf to leaf on a citrus tree in a large pot in my BBQ area. It was probably seeking to lay eggs.

As reported by sabutterflies.org.au, swallowtails are endemic in Australia, and current species evolved from ancestors which migrated from Gondwanaland/Antarctica about 40 million years ago.

Day 146. Summer Listening – Sound of Music / Radiolab mashup

When I was a kid, every couple of summers my family would travel to Perth, Western Australia to spend time with grandparents, aunties, uncles and cousins.

My grandfather lived in a fantastic apartment with a swimming pool, many bedrooms and a jar full of lollies in the pantry. In contrast to my own TV-phobic immediate family, he was an early adapter to video technology. We’d break up swimming sessions with viewing Mary Poppins, Oliver! and The Sound of Music over and over again.

Yesterday my mum – the only daughter of that grandfather – and I introduced my three children to The Sound of Music. The kids were captivated. I knew every word of course, and was somewhat surprised to feel a little tearful with all the memories that were conjured up hearing each song.  I avoided the emotion, I mean took advantage of the quiet moment, by retiring to a couch with my trusty iDevice for some secret summer science listening.

Radio National’s Science Show episode of 29th December 2012 turned out not to be a wrap of the year in science, but I wasn’t disappointed for long: their featured Radiolab Animal Minds podcast was a perfect surrogate.

I did pull my earphones out when The Lonely Goatherd scene appeared on my TV though. That was always my favourite.

[image thanks to brian395 on flickr]

Day 145. Breeding like rabbits

The rabbits are running the show down here on the foot of Yorke Peninsula.

This wee chap took a twilight stroll down the beach path as I enjoyed an early evening cocktail last night.

I’ve spotted perhaps 20 of his cousins whilst out on runs of a morning, including an enormous male specimen which I mistook for a small dog such was his shoulder height. During holidays in the same location in the past 2 years I barely spotted a single rabbit over two week periods.

The rabbits are a super-breed of sorts, survivors of two pathogens thrown at them by Australia’s CSIRO: myxomatosis and calcivirus. As explained in an The Australian newspaper article Rabbits’ return catches science on the hop,

The resurgent rabbit numbers across South Australia, Victoria and NSW follow two consecutive wet springs, abundant grass growth and growing immunity in young rabbits to the once-deadly calicivirus.

Although the current heat wave we are experiencing may have an impact on new generations, the Invasive Animals Cooperative Research Centre is running a new strategy for improved integration of existing biological, conventional and newly-developed control options for rabbits.

Day 142. Australian native road kill

Australian native road kill observed on my morning run yesterday (Adelaide) and today (Yorke Peninsula):

Rainbow lorikeet (Trichoglossus haematodus)

Brown snake (Pseudonaja textilis)