Amy Whitehead's Research

the ecological musings of a conservation biologist

Wildlife Wednesday: Kōwhai

4 Comments

Kowhai flower

The kōwhai (Sophora spp.) is a New Zealand tree legume that typically grows in open areas and along the edge of streams and lakes.   The name kōwhai comes from the Māori word for yellow – a reference to their prolific flowers and small pea-like seeds.  One of NZ’s most iconic plants, they flower from July to November and are an important source of nectar for native birds, particularly tui and bellbirds.  They are a common garden plant and most children I know spent time trying to get the seeds to grow by throwing them in boiling water or attacking them with sandpaper (okay I may have grown up in a strange neighbourhood but these are actually the best techniques for breaking the tough outer coating of the seed to get them to grow).   However, almost all parts of the tree are poisonous to humans, so don’t be tempted to take a nibble!

While New Zealand doesn’t have an official national flower, kōwhai would do pretty well in a floral showdown.  Indeed, kōwhai flowers are one of only two plants to make it onto New Zealand coins, featuring on the New Zealand 2c coin from 1967 to 1990 (the other being the silver fern on the 1c and $1 coins).  They also featured on a 3D (as in threepence, not three-dimensional) stamp released in 1960 and the 2.5c stamp when NZ converted to decimal currency in 1967.  Apparently they have also been immortalised in folksong, although I think this may have been popular a little before my time.


7 Comments

Wildlife Wednesday: Monarch butterfly

Monarch butterfly

Monday was a public holiday in Victoria in honour of the Queen.  I’ve often been intrigued by how many birthdays the Queen has in a year, given the numerous dates on which it is celebrated throughout the commonwealth.  But it turns out that we were really celebrating the (approximate) birthday of King George III, with the first Monarch’s Birthday celebration held in Australia in 1788.  So it seems appropriate to celebrate with a monarch butterfly (Danaus plexippus).

The monarch butterfly is a pretty amazing beast.  Native to North America, they migrate from Mexico to southern Canada and back every year, a journey which can take up to four generations.  They are following seasonal changes in the abundance of their main food source,  milkweed. Typically, it takes three generations to get from Mexico to Canada, with the adults in each generation living for about two months.  The fourth “super” generation can live for up to seven months and is capable of making the entire return journey back to Mexico.  That’s about 4,000 km – not a bad effort for an insect with a wingspan of ~ 10 cm!  Monarchs overwinter in a small area of forest in the Mexican mountains at the Mariposa Monarca Biosphere Reserve, with up to one billion individuals occupying  sites that cover less than five hectares within the reserve.

Not much was known about the monarch migration until Fred and Nora Urquhart began researching the monarch butterfly in 1937, recruiting an army of citizen scientists across North America to help them in their quest to find the wintering sites.  Individual butterflies were marked with small stickers on their wings and released to continue their journey.  Sightings of tagged butterflies were recorded and plotted on a map but it took 38 years before the mysteries of the monarch migration and the location of the wintering sites in Mexico were revealed.

The video below has a nice summary of both the migration and the citizen science movement (and fun things you can do with google earth).

Monarchs are also found in New Zealand (where this photo was taken), Australia and the UK.  However, they don’t make the same large-scale migrations (partly because they would totally run out of land, at least in NZ and the UK!).

Wildlife Wednesday: Ants

3 Comments

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: Black-fronted tern

1 Comment

Black-fronted tern

A few years ago I did some contract work surveying nesting populations of river birds on the Waimakariri River in New Zealand.  We walked along the river bank identifying and counting birds as part of an annual census to look at populations trends over time.  We also spent a lot of time leaping in and out of a moving jetboat onto tiny patches of gravel in the middle of the river.  That led to some heart-stopping moments!

One of the more abundant species we saw was the black-fronted tern (Sterna albostriatus).  These guys nest in colonies and tend to mob anyone or anything that gets too close, including well-meaning scientists!  Which makes the counting process somewhat difficult – “Have I already counted the one wheeling around the top of my head or is that a different one?”! Black-fronted terns only breed in the eastern regions of  New Zealand’s South Island and are usually found nesting along braided rivers.  Nests are very basic, with the eggs laid among the river gravels.  Black-fronted terns feed on freshwater fish, invertebrates and worms.  Unfortunately their numbers seem to be declining, mostly likely due to predation by introduced mammals and loss of habitat.

Wildlife Wednesday: Praying mantis

1 Comment

Praying mantis

Yesterday, a couple of colleagues and I watched a standoff between a praying mantis and a magpie lark outside our building.  Needless to say, the magpie lark eventually won but the praying mantis definitely gets bonus points for standing up to someone many times its size.

It reminded me of watching a standoff between a praying mantis and a honey bee a few years ago in my garden in Christchurch.  I was hanging out my washing when I spotted the praying mantis attempting to catch one of the many honey bees visiting the lavender bush.  It eventually grabbed one but it took some time before it was able to manoeuver it into a safe position for eating!

Wildlife Wednesday: Echidna

6 Comments


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!

DSC_1520

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

6 Comments

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).

DSC_1538_2

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.

DSC_1549

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.

DSC_1559

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.