Amy Whitehead's Research

the ecological musings of a conservation biologist


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Three new papers: urban development, agriculture & skua

What do urban development, agriculture and skua have in common? Superficially very little, except that they feature in three papers that I published in the past few weeks. These papers are the culmination of  research projects I worked on at Landcare Research and the Quantitative & Applied Ecology group at The University of Melbourne and it’s super exciting to see them finally out in print. Many thanks to the teams of co-authors who made these possible.


Protecting biodiversity while planning for development

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Clever strategic planning can identify land for urban development that minimises habitat clearing and benefits native plants and animals. Picture: WWF-Australia.

As our cities expand due to population growth, development encroaches on the natural habitat of native plants and animals. While developers often have to assess how their new subdivision or industrial park will impact on these populations, this is usually done at the scale of individual developments and often only considers a few species. The consequence of such ad-hoc assessment is that biodiversity can undergo “death by a thousand cuts” where the cumulative impacts of many development projects can be more severe than those predicted by the individual assessments. However, a lack of good tools and guidance has limited  how impact assessments are carried out. We looked at how existing conservation planning tools can use information on the distribution of many species over large areas to identify the potential impacts of a large-scale development plan in Western Australia. We worked closely with government agencies to identify important areas for biodiversity conservation and make minor changes to the development plans that significantly reduced the potential impacts to biodiversity. See our paper for more details on our framework for undertaking strategic environmental assessments.

Whitehead, A., Kujala, H., & Wintle, B. (2016). Dealing with cumulative biodiversity impacts in strategic environmental assessment: A new frontier for conservation planning Conservation Letters DOI: 10.1111/conl.12260


Can biodiversity, carbon and agricultural development coexist in Australia’s northern savannas?

Irrigated agriculture in the Ord River Development. Developing northern Australia will involve trade-offs with biodiversity. (Image credit: Garry D. Cook)

Irrigated agriculture in the Ord River Development. Developing northern Australia will involve trade-offs with biodiversity. (Image credit: Garry D. Cook)

There’s a lot of talk about developing Australia’s north, of doubling the agricultural output of this region and pouring billions of dollars into new infrastructure such as irrigation. But what about the natural values of this region and its potential for carbon storage today and into the future? Can we develop the north and still retain these other values?  We undertook a spatial analysis which found agricultural development could have profound impacts on biodiversity OR a relatively light impact, it all depends on how and where it’s done. If managers and decision makers want northern Australia’s sweeping northern savannas to serve multiple purposes then they need to plan strategically for them. For more information about how such strategic planning could be done, check out our paper and the associated press release.

Morán-Ordóñez, A., Whitehead, A., Luck, G., Cook, G., Maggini, R., Fitzsimons, J., & Wintle, B. (2016). Analysis of trade-offs between biodiversity, carbon farming and agricultural development in Northern Australia reveals the benefits of strategic planning. Conservation Letters DOI: 10.1111/conl.12255


Counting skua by counting penguins

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A skua surveying potential lunch options at the Cape Bird Adélie penguin colony.

South polar skua (Stercorarius maccormicki) like to chow down on penguins. So it makes sense that they often nest close to penguin colonies. Over the years, we’ve developed a pretty good understanding of the size of Adélie penguin (Pygoscelis adeliae) colonies around the Ross Sea, Antarctica, so we set out to see if we could estimate the number of skua associated with those colonies.  Detailed surveys of skua at three Adélie penguin colonies on Ross Island confirmed that more penguins (i.e. more lunch) means more skua.  Using this relationship, we predicted how many skua live in the Ross Sea. To find out how many skua live in the Ross Sea and for a more detailed description of the methods, check out our paper online.

Wilson, D., Lyver, P., Greene, T., Whitehead, A., Dugger, K., Karl, B., Barringer, J., McGarry, R., Pollard, A., & Ainley, D. (2016). South Polar Skua breeding populations in the Ross Sea assessed from demonstrated relationship with Adélie Penguin numbers. Polar Biology. DOI: 10.1007/s00300-016-1980-4

Wildlife Wednesday: Ants

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Ants

Last week a few qaecologists and I went on a gum tree (Eucalyptus spp.) identifying expedition up to the mallee in north-west Victoria.  It turns out that identifying Eucalytpus is actually quite difficult – they all pretty much look the same and the species we were looking for differ only by subtle changes in the shape of the buds or fruit.  I am glad I  work on virtual plants!

But we did see lots of  interesting things, including these large ants on a shrub that had recently been burnt in a bushfire.

Wildlife Wednesday: Echidna

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For as long as I have known about echidna, I’ve wanted to see one.  Something about the whole mammal that lays eggs thing that is just so weird but totally intriguing.  So every time I’ve been out in the wilds of Australia, I’ve been looking for one of these spiky little critters.  But alas I’d been unsuccessful, despite spotting plenty of signs that echidna were in the neighbourhood.

That is until I went to the Dryandra Woodland in Western Australia. We were on a walk that was touted for its abundance of woylie diggings and numbats.  We saw plenty of diggings but no numbats and were lamenting this fact towards the end of the walk when there was a noise in the undergrowth caught our attention.

Echidna!

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Often referred to as spiny anteaters, echidna are covered in spines and coarse hair and have a long slender snout.  They tend to be solitary and are powerful diggers with strong legs and claws.  I think that echidna diggings look superficially like a turtle has been flailing about in the leaves (others may just think I’m weird!).  Echidna feed on ants, termites, worms and insect larvae which they dig out of rotting logs and anthills.  They don’t have any teeth, instead collecting prey with a long, sticky tongue that protrudes from their snout.

As I eluded to earlier, echidna are monotremes – mammals that lay eggs.  This is clearly an unusual strategy, with platypus making up the only one other group of monotremes.  I had always assumed that laying eggs meant that echidna would build nests.  But it turns out that female echidna actually lay a single leathery egg and carry it around in a rear-facing pouch similar to the pouches of marsupials.  The egg hatches after about 10 days and the puggle (the name for a baby echidna) spends about 2-3 months hanging out in the pouch.   It suckles from patches in the skin that secrete milk as monotremes don’t have nipples.  Once the puggle begins to develop spines, it gets kicked out of the pouch (fair enough!) and into a nursery burrow.  The female echidna will return every five days or so to feed the puggle until it gets weaned at about seven months.

Echidna are found throughout Australia and New Guinea, with three recognised genera.  Only one species occurs in Australia, the short-beaked echidna (Tachyglossus aculeatus).  The name echidna comes from greek mythology – Echidna was half woman, half snake and was mother of all monsters (she sounds like a charmer!).

Wildlife Wednesday: A menagerie of mammals

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While I was in Western Australia, we took the opportunity to go to Barna Mia, a wildlife sanctuary for endangered mammals run by the Department of Environment and Conservation.  Located in the Dryandra Woodland, Barna Mia is primarily a breeding facility for small endangered mammals that sadly in most cases are now extinct on the mainland.  The idea is that species are bred in captivity and released back into existing or new populations in the wild where fox numbers are kept low through predator control. This work was successful for a number of years until it became apparent that the fox control had some unintended consequences: the dreaded meso-predator release where the removal of foxes led to an increase in the number of feral cats.  The newly established populations of small mammals were largely wiped out and releases back into the wild have been put on hold until DEC can figure out how to successfully control the cats.

In the meantime, Barna Mia is open to the public for evening viewings of interesting nocturnal beasts, so we went along to check out some of the inhabitants.  Held in a 4ha fenced enclosure, animals are attracted to viewing stations just after dark by offerings of food which supplements their natural diet.  We sat quietly and searched for animals using red spotlights while a ranger explained the ecology of each species as we spotted it.  It was an interesting evening and we were rewarded with five new species to check off the list (not that I would do such twitcher-esque things!) .  So today you are treated to a menagerie of mammalian delights* (plus a bonus owl).

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The bilby (dalgyte – Macrotis lagotis) has to be one of the weirder looking marsupials out there.  With rabbit-like ears, an anteater-ish snout and a long tail, they are definitely hard to confuse with their closest relatives, the bandicoots.  They are omnivorous and excellent burrowers, creating extensive underground tunnels.  Interestingly, a bilby’s pouch faces backwards, apparently to prevent it filling up with dirt when they are burrowing.

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The quenda (southern brown bandicoot – Isoodon obesulus) is omnivorous and leaves tell-tale conical pits in the surface of the soil as it digs for insects, spiders, tubers and fungi.  They spend the day tucked up in small nests of vegetation under dense cover.  Quenda are the most common of the mammal species at Barna Mia and are found across most of southern Australia.  However, they are vulnerable to fox predation.

woylie

Woylies (brush-tailed bettong – Bettongia penicillata) were once found across 60% of Australia but are now confined to less than 1% of the mainland and a couple of offshore islands.  They are currently listed as critically endangered by the IUCN and recent declines are thought to be a combination of fox predation, changing fire regimes, habitat destruction and a possible disease outbreak.  Woylies are omnivorous but predominantly feed on fungi which they dig up from underground with their strong front claws.  The fungi are digested by bacteria in a special part of their stomach.  These bacteria release nutrients that can then be absorbed by the rest of the digestive system.  It’s thought that they would have played an important role in dispersing fungi spores across the landscape.  Woylies spend the day in dome-shaped nests, which they build from dried grasses and leaves that they carry in their prehensile tail.

mala

Mala (rufous hare-wallaby – Lagorchestes hirsutus) are the smallest of the hare-wallabies, members of the macropod or kangaroo family.  They are nocturnal and solitary herbivores, feeding on leaves, seeds and herbs.  Extinct on the Australian mainland, mala are now confined to two island populations off the Western Australian coast and a handful of captive breeding facilities, including Barna Mia.

boodie

Boodies (burrowing bettong – Bettongia lesueur) are small nocturnal marsupial that lives in communal burrows, the only burrowing member of their suborder (Macropodiformes).  Boodies are omnivorous, feeding on seeds, fruits, flowers, roots, fungi and termites. They were once widespread throughout semi-arid Australia but were extinct on the mainland by the 1960s.  They are now confined to several offshore islands and captive facilities.    Declines have been attributed to fox and cat predation, competition with rabbits, livestock grazing and changing fire regimes.

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Not part of the official tour but we also came across this owl perched on a branch, watching as we pitched our tent.  Scientific deduction (i.e. random flipping through the Field Guide to Australian Birds) suggests that it is a southern boobook (Ninox novaeseelandiae) but I could have totally made this up.  Please correct me if I’m wrong!

Amy Whitehead

Well done to those of you who have made it all the way to the bottom of this post!  In lieu of an prize, I’m going to treat you to a very brief explanation of my new photo watermark.  As you should have noticed by now, my last name is Whitehead.  Which is quite apt when you consider how early the males in my family go grey!  But the whitehead (Mohoua albicilla) is also a New Zealand forest bird.  So to celebrate my tendancy towards bird nerdness, I’ve designed a new logo.  I’d love to blog about whiteheads (of the avian variety) on Wildlife Wednesday sometime but given I’ve only seen them twice, never managed an identifiable photo and currently live in Australia, you may have to wait a while!

* I was going to drag this out to five Wildlife Wednesdays but that seemed like cheating.

Wildlife Wednesday: Western spotted frog

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Western Spotted Frog

I spent Easter in Western Australia camping along the southern coast and out in the wheatbelt.  We spent a couple of nights in the Dryandra Woodland, a remanent patch of eucalypt forest in the wheatbelt.  Not a bad place to spend some time, particularly if you are looking for Easter bilbies (more on this next week).

I was trying to take a photo of an inquisitive brushtail possum (something that felt quite strange being a kiwi who is used to trying to kill them) when I spotted two glowing orbs in the darkness. And then they blinked.  It was a little bit creepy and it was with some trepidation that I cautiously approached them to see if I could identify the owner (it didn’t help that my partner was winding me up with made-up (I hope!) horror stories of giant Australian nocturnal spiders!).    It turned out that we were being watched by a Western spotted frog (Heleioporus albopunctatus) who sat very obligingly for some time while the ecological paparazzi snapped away.

These guys get up to 7.5 cm in length and are pretty solid as far as frogs go.  They are found throughout the wheatbelt region of Western Australia and are typically associated with swamps and temporary water bodies.  Once the autumn rains begin, males dig burrows up to 1m deep and sit in the bottom calling to attract a mate.  Mating occurs at the bottom of the burrow (out of the sight of prying eyes) and the females lay their eggs.  The burrows will fill with water after rain and tadpoles hatch out and are washed into larger water bodies where they take 2-3 months to develop into frogs.

Wildlife Wednesday: Yellow-billed Spoonbill

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This handsome chap is a yellow-billed spoonbill (Platalea flavipes) hanging at the top of a dead tree in Yanchep National Park just north of Perth.  I spotted it from about 100m away and, despite my best sneaking efforts, only managed to shoot a few frames before it flew majestically off into the distance.

Yellow-billed spoonbills, like their royal spoonbill cousins, live close to waterways.  They walk slowly through the water to disturb small animals in the mud, sensing the vibrations of their prey with the edges of the “spoon”.  They use this weird-shaped bill like forceps to snap up tasty treats, including yabbies, shrimp, insect larvae and small fish.  Yellow-billed spoonbills are found across most of mainland Australia and occasionally in New Zealand, Lord Howe Island and Norfolk Island.

 

Wildlife Wednesday: Kookaburra

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Kookaburra

Given that I’m back in Melbourne, and this week we celebrate Australia Day, I thought it only fair that I post a picture of something Australian.  Now, being a kiwi who has only recently crossed the ditch, I should confess that I know very little about Australian wildlife (except for the damage that brushtail possums do in NZ).  In fact, most of what I know about the kookaburra comes from the children’s nursery rhyme!

Kookaburra are well-known for their (slightly creepy) laugh-like call , which is used to establish territory boundaries.  They are carnivorous and will perch on branches waiting to launch themselves onto unsuspecting prey, such as lizards, large insects and small mammals.  This handsome fellow was hanging out along the Great Ocean Road outside a cafe, where it made a living swooping down on the lunch of unsuspecting tourists!