Australian Geographic Lord Howe Island citizen science insect expedition (part 1)

To paraphrase Orson Welles, I don’t know much about insects, but I know what I like. If I knew more, I suspect I would like them even more. Both massively useful and massively destructive, they fascinate me with their different body forms. We couldn’t live without them as they pollinate our crops and provide chocolate, too. Yes, really.

The Australian Museum says:

It is estimated that Australia has over 300,000 insect species, but only 160,000 have been named or described.

Museum Victoria says:

Insect species make up … the largest of all animal groups. Of all the animal species on Earth that scientists have named and described, 75% are insects. … The number of individual insects estimated to be alive in the world at any one time is 10 quintillion, or 10,000,000,000,000,000,000. It is figured that for every human being on the planet there are about 200 million insects.

Sometimes it seems they are all in my backyard at once. 🙂

So when the Australian Geographic Society announced a citizen science project to Lord Howe Island with the Australian Museum, looking at insects, I jumped at the chance. I initially missed out on the 2016 trip as it was already fully booked, but asked to be notified if anyone dropped out. A couple did, and I took over their room at the last minute. The Australian Museum also dropped out and was replaced by three of CSIRO’s Australian National Insect Collection scientists. You can read an overview of the week by trip coordinator Luke Hanson here.

I’d been to Lord Howe Island three times before (click on ‘Lord Howe Island’ in the word cloud on the right for my other posts on the place) and didn’t think I’d go again, but this project was too enticing to ignore. The island is visually stunning with its mountains, lagoon, forests and tropical lagoon. It may be one of the most studied islands in the world from a natural history perspective, as a World Heritage Marine Park should be.

Mt Lidgbird (left) and Mt Gower (right); you can go with a guide to the top of Mt Gower to see the unique cloud forest and providence petrel breeding area

Mt Lidgbird (left) and Mt Gower (right); you can go (only with a guide as it’s not a good place to get lost) to the top of Mt Gower to see the unique cloud forest and providence petrel breeding area

Day 1

The two-hour flight from Brisbane was uneventful, unlike one other time when our 10-seater (I think – it was tiny) plane flew through a massive storm. That was in the days when cabin service was a biscuit tin and thermos passed round. The turbulence, thunder, lightning and hailstones beating on the windscreen were terrifying. I thought I was doing OK, but when I got off the plane at the other end, I couldn’t unclench my fists for several minutes! Fortunately, it was perfect flying weather this time, and remained so every day except the last one. Weather on the island is volatile, so we were fortunate to have a run of good days with max. temps in the early 20s (Celsius). Perfect for walking.

It’s always a thrill to see the island from the air, and the pilots kindly do a circuit before landing. Ball’s Pyramid was especially clear that day so we got a good view.

Ball's Pyramid; photo by National Geospatial-Intelligence Agency, Wikimedia Commons

Ball’s Pyramid; photo by National Geospatial-Intelligence Agency, Wikimedia Commons

The geology of Lord Howe is most interesting; it and Ball’s are remnants of a massive volcanic explosion six million-ish years ago. There’s more on the geology later in this post.

I’d arrived in mid-afternoon so there were a couple of hours to kill before the meeting at 6 pm. I arranged my gear in my room at Pinetrees and walked to the museum. (You either walk or ride a bike on the island as most things are close. There’s a couple of cars for hire, but you only need them if you can’t walk, ride or hitch a lift with the lodge staff.) It’s a compact but well-presented museum, with a room for natural history and one for social history, a meeting room, a cafĂ© and an entrance room with the usual souvenirs for sale.

I walked back along the beach, looking at what was washed up and soaking in the atmosphere. You could take photos of the mountains every half hour and find the clouds on their tops changing shape. Heart urchins, a type of sea urchin, are very common in the lagoon and their tests often wash up. When alive, they have short brown spines.

Heart urchin, Breynia australasiae

Heart urchin, Breynia australasiae

heart-urchin-breynia-australasiae-2

The meeting was a get-to-know-you affair, where we each said who we were and what our interests were, and Luke Hanson, trip coordinator and Pinetrees owner/manager, laid out the approximate plan for the week. Weather always dictates what to do (or not do, if you want to go up Mt Gower on the eight-hour guided walk) so we had to be flexible. There were 20 participants and three scientists, quite a large ‘expedition’. Bry the Fly Guy (Dr Bryan Lessard) hadn’t arrived yet, but Dr Andreas Zwick and his co-moth-er Glenn Cocking had brought masses of equipment from the mainland. (They obviously didn’t have the 14 kg weight limit we ordinary folk had to adhere to, but how else are you going to get a couple of generators, lights, traps, a zillion plastic specimen bottles and alcohol – no, not the drinking sort but the preserving sort – onto the island?)

Last thing on the day’s agenda was the evening meal, which was full-on, three-course restaurant service. The food was delicious and healthy, and beautifully plated up, but the noise level was quite high because about 70 people were being served that night. There was another tour group of about 20 and miscellaneous other guests for the week. It was difficult to hold a conversation, and this was the case every night. We were certainly well fed throughout the trip, though, and the staff were all friendly, professional and courteous. Well done, Pinetrees, for your choice of staff.

After dinner I walked along the lagoon beach again, with the full moon shining on the lagoon and the mutton birds calling from their burrows – stunning stuff, the sort that brings tears of joy to your eyes.

Day 2

After brekky, we headed off through the forest to Soldier Creeks and along the Rocky Run Creek track to the ocean on the other side of the island. Andreas led the charge with insect net and stopped to tell us about anything insectival we found. This was also a reconnaisance mission to find areas suitable for putting up UV light traps at night to catch moths (Andreas’s main interest, although he’s also into intertidal crustaceans – a man after my own heart).

Andreas explaining about leaf miners

Andreas explains what leaf miners do; note the tall roots of the pandanus – much taller than those on the mainland – behind us

Abdreas checking for insects under a rotting log; Dean Hiscox (back) fills us in on various aspects of LHI ecology

Andreas checks for insects under a rotting log; Dean Hiscox, LHI environmental guide (back), fills us in on various aspects of LHI ecology. The log was carefully replaced in its original spot afterwards.

The kentia palm, a popular house plant since Victorian times and an important part of the LHI economy until recently (owing to overseas kentia-growing industries starting up), is endemic to Lord Howe. Some parts of the forest are pure kentias, with the occasional banyan.

Endemic kentia palm - note the red seeds

Endemic kentia palm – note the red seeds

Banyans (Ficus macrophylla) grow huge on LHI. These figs grow fibrous aerial prop roots that eventually reach the ground and thicken up to provide support for the vertical limbs, allowing a single tree to cover a large area, the largest one estimated to cover five acres. National Geographic published an article on research into the LHI banyans here.

The aerial roots eventually look like the main trunk

The fibrous aerial roots eventually look like the main trunk and support the spreading ‘arms’ of the fig.

When we got to where Rocky Run Creek meets the sea, Dean Hiscox described the geology of the region. The Lord Howe Island website says the old shield volcano:

has been eroded to one-fortieth its original size. Lord Howe’s crescent shape embraces a sheltered lagoon and the southernmost coral reef on the planet.

Balls Pyramid, Lord Howe and its islets form part of a chain of seamounts that extend north for 1,000km and are thought to be the result of the Indo-Australian tectonic plate moving northward over a stationary hotspot. The chain forms part of the undersea plateau known as the Lord Howe Rise.

The island itself is dominated by the basalt peaks of Mt Lidgbird, 777m and Mt Gower, 875m, at the southern end of the island – virtually all that remains of 6.4 million-year-old lava flows that filled a large volcanic caldera.

From the south, the island slopes more gently towards the north, with beautiful sandy beaches on the eastern and western sides, and a large portion of the island covered in dense forests. Spectacular cliffs buttress the eastern side, which offers dramatic views of the offshore rocks, islands and along the spine of the island south to Mount Lidgbird and Mount Gower.

Dean Hiscox tells the geological history of LHI

Dean Hiscox tells the geological history of LHI while we sit on some volcanic remnants.

Then it was back through the forest via Mutton Bird Point to the lodge for lunch. Our postprandial walk was to the Middle Beach rock pools at, coincidentally, the lowest tide of the year.

Middle Beach rock pools

Middle Beach rock pools; Admiralty Islands, bird-breeding islands, on the back left horizon

This imperial hermit crab (Calcinus imperialis) had taken a shell of the endangered land snail, the Lord Howe flax snail (Placostylus bivaricosus). Apparently it is rare to see this land snail alive, although there are plenty of their empty shells about. You can read more about LHI’s endangered land snails here. (I’m taking my IDs primarily from Neville Coleman’s Lord Howe Island Marine Park Wildlife Guide and some internet sites; all mistakes are entirely mine.)

Calcinus imperialis (hermit crab) in shell of Placostylus bivaricosus

Calcinus imperialis (hermit crab) in shell of endangered land snail Placostylus bivaricosus

Only one species of turban shell (Turbo cepoides) has been found on LHI, unlike the three (T. undulatus, torquatus and imperialis) in Australia.

Turbo cepoides

Turbo cepoides

Turbo cepoides, showing operculum

Turbo cepoides, showing its thick operculum

Waiting for the tide to come in: possibly the rug anemone Stichodactyla tapetum

Waiting for the tide to come in: I’m guessing (red, left) tuberculate sea urchin (Heliocidaris tuberculata) and (blue) the rug anemone (Stichodactyla tapetum)

Hermann's sea cucumber (Stichopus hermanni)

Hermann’s sea cucumber (Stichopus hermanni)

black-fringed-sea-cucumber (covered in sand, Holothuria leucospilots)

Black sea cucumber (covered in sand, Holothuria atra)

I'm not sure of the species of this cone

I’m not sure of the species of this cone – Conus lividus?

Elongate giant clam, Tridacna maxima - this one was less than a foot long

Elongate giant clam, Tridacna maxima – this one was less than a foot long

Sea hare, Aplysia dactylomela

Sea hare, Aplysia dactylomela

Ivory cone, Conus-eburneus

Ivory cone, Conus eburneus

The ivory cone doesn’t look ivory-coloured when alive, but when dead the thin yellow periostracum (organic coat) rots off, leaving the black and white pattern.

White-spined sea urchin and bluebottle

White-spined sea urchin and bluebottle

Beautiful pattern inside this crab shell

Beautiful pattern inside this crab shell (probably the common box crab, Calapa hepatica)

Sooty terns were incubating chicks on the ledges above the rock platforms, and some young chicks were evident. There must  have been thousands of them on the island, each nesting just out of pecking range of another bird.

Sooty terns and chicks, Middle Beach

Sooty terns and chicks, Middle Beach

After dinner, Andreas took some volunteers to set up some UV light traps and catch anything that turned up in a couple of hours. Andreas and Glen would go out to the trap sites at night and catch the moths on the sheet, snatching sleep where they could until dawn. Then it was back to the research station to store the specimens and do some pinning and DNA sampling during the day.

Light trap for capturing moths and other night-flying insects, set up in Stephens Reserve

UV light trap for attracting and capturing moths, beetles and other night-flying insects, one of two set up in Stevens Reserve

 

 

 

 

 

 

 

 

 

 

 

 

I’ll continue the trip report in the next post.

Spring low tide at Flat Rock

The rock pools at Flat Rock have been covered in sand for a few months, but gradually the sand is clearing and seaweeds and algae (with associated fauna) are coming back. The lowest tides of the spring give a good opportunity to go further out on the platform than usual.

Here’s a nudibranch I’d not seen before, although they are apparently common – Sebadoris fragilis. They grow up to 12 cm and this one was about 8 cm long. (IDs courtesy of Nudibranchs of the Sunshine Coast).

Discodoris fragilis

Discodoris fragilis

discodoris-fragilis_2 discodoris-fragilis_3

There was only one Discodoris fragilis, but over a dozen Plocamopherus imperialis – breeding time? They can grow up to 10 cm, but this one wouldn’t have reached 2 cm.

Plocamopherus imperialis

Plocamopherus imperialis

plocamopherus-imperialis_2

plocamopherus-imperialis_6red-and-orange-nudibranch-at-flat-rock-2Also common is Rostanga arbutus, max. size 1 cm. It’s tiny.

Rostanga arbutus

Rostanga arbutus

Below is possibly Kaloplocamus acutus – if it is, it’s way off the 6 cm length of adults. This one might have been 1 cm.

Kaloplocamus acutus

Kaloplocamus acutus?

It was definitely breeding season for the limpets …

Limpet egg masses

Limpet egg masses (white circles)

… and the cartrut shell (Dicathais orbita). The egg cases are yellow when ‘fresh’ and go purple after a while. (The purple cases below are in front of and separate from the yellow cases behind.)

egg-cases

Cartruts in the process of laying eggs

cartrut-eggs_1 cartrut-eggs_2This live shell (possibly Cabestana lampas) is common, but I saw only one …

Cabestana lampas

Cabestana lampas

Note the 'eye stalks' and syphon

Note the ‘eye stalks’ and siphon (left); photo by Andrew

Black feather duster worm …

black-feather-duster-worm

We saw three small sharks resting in the crevices, but it was impossible to get decent shots because the water was rippling through fast. One was a clearly a wobbegong but the other two were different.

There were over a dozen sea hares, perhaps in preparation for mating, too. They form mating chains, one behind the other.

Aplysia dactylomela

Aplysia dactylomela

aplysia_2A lot of birds were resting on the platform. It annoys the heck out of me when people allow their dogs to run free there – no dogs are meant to be on the platform, and only dogs on leashes on the beach. The migrating seabirds need rest and refuelling.

A pair of beach stone-curlews (Esacus magnirostris, aka beach thick knees because that’s what they have) flew quickly past, crying their curious call. It was the first time I’d seen this species in the wild.

Beach stone curlews

Beach stone curlews

Beach stone curlews

This is either the grey-tailed (Heteroscelus incanus) or the wandering (Heteroscelus brevipes) tattler. The grey-tailed is more common.

Tattler

Tattler; photo by Andrew

I think the birds below are sandpipers, but there are a lot that look alike and I haven’t worked out how to distinguish them yet. Any ideas appreciated.

Unknown

Sandpipers?

Another nice nudibranch

The new moon brought a very low tide, so off to Flat Rock. Fortunately it’s recovered from all that sand over winter, and there were lots of animals, shells and so on in the rock pools.

I was especially pleased to see this nudibranch (Austraeolis ornata), apparently a common one but I’d never seen it before. I only spotted it because I stopped to admire a Peron’s side-gilled sea slug that happened to be next to it.

Nudibranch, Austraeolis ornata

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A silver star for Christmas

Best Christmas present! This glaucus washed up by the heavy seas courtesy of the cyclone up north …

Glaucus atlanticus, a nudibranch, floats on the surface of the ocean, along with other members of the “blue brigade“. It can wriggle a bit, as this one was in its pond, but is mostly at the mercy of wind and currents, as are its confederates.

It feeds on the bluebottle, Physalia physalia, and moves the bluebottle’s stinging cells from its stomach into its own tips, so anything trying to eat it will get a mouthful of bluebottle stings. Other nudibranchs do this: see Evolution Happens for a description.

This one was about 3 cm long. The hole on the left side is a reproductive pore. Glaucus is a hermaphrodite.

I don’t see them very often, and this one was a special surprise on Christmas morning. Thanks, Mother Nature!

Sea cucumbers, stars and urchins on Lord Howe

I was going to call this post “the pentaradials”, because sea cucumbers, sea stars, brittle stars and sea urchins all have similar body plans (fivefold symmetry), but decided I was trying too hard. It’s a good excuse to group them together, though.

Sea cucumbers

The black sea cucumber (Holothuria leucospilota) common on Lord Howe is the same one as on the coast at home. I’d often wondered what the internal structure of a sea cucumber was, and as luck would have it (although not for the sea cucumber), there was a dead one on the beach.

What’s inside a black sea cucumber

When you disturb one, it’ll sometimes spit out white stringy filaments – these are the Cuvier’s tubules, the white stuff on the left of the picture. They become very sticky on contact with water and are apparently toxic, so a defense mechanism for this animal. I didn’t realise there was so much of them inside. The sausage-looking structure is indeed the intestine. One of the other structures is the respiratory tree, the equivalent to our lungs.

[Update: you can see the internal structure of a sea cucumber and find out about its eating habits at Deep Sea News here.]

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Shells in Lord Howe Island rock pools

Lord Howe has many marine species similar to those in other parts of the Pacific – the eggs and larvae get washed along in currents from other places, and survive to adulthood if they don’t get eaten or if they find a place that suits their needs.

Survival pressures can also push species to evolve into new ones that occur only in the “new” home (by then not at all new). In other cases, such changes do not proceed because the conditions already suit.

My favourite rock platform find is probably this cowrie, Staphylaea limacina (many thanks to Sallyann Gudge, Lord Howe Island Marine Park Marine Ranger, and the Australian Museum for confirming the ID).

Many cowries have elongated papillae like these.

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Two little beauties

I used to work in the Marine Invertebrate section of the South Australian Museum, and the curator and his assistants (including me) would go on field trips to get specimens, especially for our marine tank. This was not on display to the public, but I quickly learnt that marine tanks are fussy to look after and can turn into a stinky mess overnight.

We’d get rocks with lots of weeds and put them in the tank. It was always exciting to come in the next morning and see what had crawled out – especially nudibranchs.

We’d bottle them up in formaldehyde and send them off to the expert at Museum Victoria in Melbourne, Bob Burn, who often discovered that many of these were new to science. He had the fun and privilege of describing and naming them. There’s no windowii, though.

It’s still exciting for me to see a nudibranch, and these days there are many websites, books and CD-ROMS available to help with ID.

Here are two new – for me – nudibranchs from Flat Rock last weekend. They were both about 2 cm long.

Plocamopherus imperialis on a half-shell

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High noon, low tide at the rock pools

Around spring equinox, the low tides are lower than usual. The sand deposited by winter storms is starting to be washed off the rocks, and there is now lots of life in the Flat Rock rock pools, although surprisingly few humans on the beach, considering it is the start of a fortnight of school holidays.

I can’t resist a nudibranch, even though I’ve already posted another photo of this one, Rostanga arbutus

Nudibranch, Rostanga arbutus

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