Room for one more?: Egg fostering in seabirds

 

Picture 1 and cover picture

When attempting to conserve a rare animal population sometimes every individual counts. Conservationists regularly go the extra mile to protect their study species. The conservation efforts implemented for the Little Tern (Sternula albifrons) in Britain and Ireland demonstrate the success these efforts can have. This species nests on shingle beaches and had experienced catastrophic population declines due to increasing development and use of beaches by people. Little Tern adults are very vulnerable to disturbance and their eggs are particularly vulnerable to walker’s boots! Thankfully a network of wardened colonies, run by a mixture of conservation organisations and enthusiastic volunteer groups, succeeded in stabilising this species’ population.

However the Little Tern has lost much of its former range and is increasingly dependent on wardened colonies for their continued existence on these islands [1]. Being concentrated in a densely populated protected areas has made them acutely vulnerable to predators. This has led wardens at the nationally important colony at Kilcoole in Co. Wicklow to adopt a practice of fostering Little Tern eggs abandoned after a depredation event in an attempt to maximise colony productivity, outlined in our recent paper in the latest issue of Irish Birds.

 

Picture 2

As Little Tern colonies are often squeezed into small protected areas this makes them a beacon to hungry predators. Corvids (members of the crow family), can be a danger to colonies. They are vigorously mobbed by the terns, but sometimes manage to slip through the defences. It was noticed that corvids often only managed to take one egg from a nest, perhaps because the parents were then more vigilant. However within a day of having an egg taken, the parents abandoned the remaining eggs in every case observed. This may have been due to anticipation of the predator’s return (Little Terns depend upon their egg’s camouflage to protect their nest), or in an attempt to re-lay a full clutch. However clutches laid later in the season often have poorer survival rates [2].

To maximise colony productivity, Kilcoole wardens fostered abandoned eggs abandoned after depredation events to other nests on the same incubation schedule when the colony experienced corvid depredation in 2011 and 2014. Nests were confirmed abandoned after the parent’s failed to return to incubate for several hours and the eggs went cold. The parents in recipient nests always accepted the foster eggs, apparently not questioning why they had gained an extra egg! Where possible eggs were fostered to other nests which had experienced partial depredation but had not yet been abandoned, replacing the eggs lost. Having a full clutch again seemed to stop the parents abandoning the nest. Fostering eggs resulted in the fledging of an additional 5 Little Tern chicks, a small but worthwhile number given the precarious status of the Irish populations.

The fact that the fostered eggs remained viable despite hours without incubation in cold conditions further demonstrate the extraordinary robustness of seabird eggs. In a previous paper we wrote about how Little Terns recollected eggs which have been washed out by tides and moved them into new nests. Many of these eggs hatched successfully even after hours without incubation, exposure to freezing seawater and potential mechanical damage from being moved.

 

Picture 3

This robustness can prove a boon for conservationists working with endangered species. In a recent case an egg abandoned by an inexperienced pair of Chatham Island Tāikos (Pterodroma magenta) was successfully fostered to another pair after being abandoned for 10 days. Even after all this time without incubation a healthy chick was hatched, an important victory as only 150 of these birds are left in the world, showing the potential value of egg fostering.

 

Picture 4

While the aspiration must always be for animal populations to be self-sustaining, in many cases hands on conservation measures are necessary to ensure a population’s survival. In order to ensure the continued survival of the Little Tern in Britain and Ireland wardened colonies are still necessary, at least until they experience a full tern around in fortunes.

 

Author: Darren O’Connell

 

Photo credits: Little Terns – Andrew Power and Peter Cutler. Chatham Island Taiko Chick – Dave Boyle.

 

A special thanks to all my co-workers on the Kilcoole Little Tern project, the volunteers who make the project tick and project manager Dr Stephen Newton of BirdWatch Ireland.

 

[1] Balmer, D., Gillings, S., Caffrey, B., Swann, B., Downie, I. and Fuller, R. (2013) Bird Atlas 2007-11: the breeding and wintering birds of Britain and Ireland. HarperCollins, UK.

 

[2] Nager, R.G., Monaghan, P. and Houston, D.C. 2000. Within-clutch trade-offs between the number and quality of eggs: experimental manipulations in gulls. Ecology 81: 1339-1350. DOI: 10.1890/0012-9658(2000)081[1339:WCTOBT]2.0.CO;2

Wild Goose Chase – cannon netting on the Inishkea Islands

Last March we had the fantastic opportunity to assist with cannon netting Barnacle Geese on the Inishkea Islands, a wild Atlantic outpost off the coast of Co. Mayo. This research was part of Dr David Cabot’s long term study of the Inishkea Barnacle Goose population, which breed in Greenland and return to the west coast of Ireland each winter. Dr Cabot has been studying this population since 1961, providing the longest running dataset of any Arctic migrant breeding in Europe. He established the project as an undergraduate in our very own Zoology Department in Trinity (back in the good old days when Catholics could only join Trinity with the permission of their Archbishop, lest they be corrupted by the insidious Protestant ethos of the College of the Holy and Undivided Trinity of Queen Elisabeth!!). Our part in Inishkea was to help catch geese to attach unique inscribed colour ring combinations to their legs. This allows individuals to be tracked to provide information on individual longevity and productivity. Re-sighting of these colour ringed individuals coupled with satellite tracking data have also allowed the timing and route of this population’s migration to be mapped out. Such monitoring is important as a large proportion of the Greenland population of Barnacle Geese winter in Ireland, and Inishkea is one of their most important wintering grounds.

Barnacle Geese grazing alongside sheep among the old houses. © David Cabot.
Barnacle Geese grazing alongside sheep among the old houses. © David Cabot.

As a field site, the Inishkea Islands are mysterious and intriguing. The last of its inhabitants departed in the 1930s following a devastating storm that killed 10 young fishermen at sea. The ruins of the abandoned village, the sea mists and windswept machair lend the landscape an air of wildness. One thing that cannot be denied is that the islands are a haven for interesting wildlife. In Irish they are called Inis Gé, translating as ‘Goose Islands’, and they don’t disappoint. Large flocks of Barnacle Geese still winter in Inishkea, the population having benefited from the cessation of human habitation. As well as the geese, breeding waders such as Lapwing, Redshank and Snipe (particularly within a sheep exclusion fence on the north island) and seabirds such as Fulmars and Little Terns are present in large numbers, along with a colony of several hundred Grey Seals.

Sanderling. © Christian Glahder.
Sanderling. © Christian Glahder.

Therefore we eagerly anticipated our chance to take in the spectacle these islands have to offer. But there was serious business to attend to – catching a sufficient sample of geese to add to the study is a task far easier said than done!  We used a trapping technique called cannon netting. This is a method for catching ground feeding gregarious birds that is just as weird and wonderful as it sounds! A large net is attached to weighted projectiles, which are fired from a series of mortars, propelling the net (hopefully) over its intended target. Unsurprisingly this is a tightly regulated activity, and only three individuals in Ireland are licenced to catch birds this way and only in specific circumstances.

Our catching attempts on Inishkea were led by Alyn Walsh of the NPWS, helped by Dr Cabot’s knowledge of the islands and goose habits. Working with Alyn was an education in fieldcraft, patience and meticulous preparation. The trick to cannon netting is positioning your net in a place your target species will walk straight into. In our case, the geese had a whole island to choose from, so our positioning had to be spot on. Before a catch was attempted, the movements of the goose flocks were carefully observed for their patterns of grazing, looking for natural choke points in the landscape that would draw the geese together in a suitable position for projecting the nets. Following a day of observation, one promising site was selected and baited with barley to attract and then hold the geese in place. By day three on the island, we were confidently prepared for our first attempt. The net was laid and disguised with grass and its mortars were dug in so that only their tips protruded, in the hope the geese wouldn’t know something was amiss…

Digging in the cannons © Darren O’Connell.
Digging in the cannons © Darren O’Connell.

The morning of the catch was akin to the dawn of a battle. Barnacle Geese are not like their more familiar cousin the Brent Goose, which will happily graze in urban parks by busy roads and playgrounds. Barnacle Geese are exasperatingly wary. Any sight of people (even from hundreds of metres away) will send an entire flock off over the horizon. Dr Cabot’s cabin served as our bunker from which we spied on the geese through twitching curtains. Our nerves were on edge as the first goose heads appeared on the brow of the hill and began a steady march grazing towards the catching zone, where the cannons and nets awaited. Any person leaving the single roomed cabin for a ‘comfort break’ was at great risk of alarming the geese. Because of this, we were required to scramble on hands and knees until we reached the cover of the old village, darting from house to house, being sure not to break the skyline and keeping our heads down as if from sniper’s fire.

Having waited in the darkened cabin since dawn, the goose battalion entered our baited field at midday. Lulled into a false sense of security by our extreme stealth and the unexpected windfall of barley, a group of geese fell asleep in the sun – right within our catching zone! They were rudely awoken when (as soon as all birds were in a safe position relative to the cannons) Alyn judged it was time to fire! After two days in the bunker, the blast of the cannons and the smell of gunpowder provided us a suitable adrenaline jolt into manic activity. Following a breakneck sprint to the net, we secured all of the birds safely in special bird-bags (a fantastic catch of 29 geese, the second biggest ever achieved on the island!). To keep handling time to a minimum, we formed a goose “production line” to maximise efficiency in fitting rings, taking morphological measurements and recording data. Processed geese were kept in a holding pen and then released to the wind together in batches of ten. We were lucky to have some geese that had been ringed several years previously, providing valuable data, along with many newly ringed geese.

Extracting geese from the net after cannon fire. © David Cabot.
Extracting geese from the net after cannon fire. © David Cabot.
The team with our goose booty! L-R: Richard Nairn, Darren O’Connell, David Cabot, Maurice Cassidy, Susan Doyle, Alyn Walsh (and Christian Glahder behind the camera!). © Christian Glahder.
The team with our goose booty! L-R: Richard Nairn, Darren O’Connell, David Cabot, Maurice Cassidy, Susan Doyle, Alyn Walsh (and Christian Glahder behind the camera!). © Christian Glahder.
A goose receives its colour rings. © David Cabot.
A goose receives its colour rings. © David Cabot.

We left Inishkea, satisfied with our work and delighted with our experience in this challenging form of bird monitoring. We hope to see many of the geese we caught this year back in Inishkea with goslings after a successful season in the Arctic.

Authors: Darren O’Connell and Susan Doyle

A special thanks to Dr David Cabot, Alyn Walsh, Richard Nairn, Maurice Cassidy and Christian Glahder, for making us part of the team.

Dig for victory

In a previous post I showed what I think being a palaeontologist is all about, especially the point that palaeontologists are different from oryctologists. The first ones study changes of biodiversity through time, the second ones extract fossils (but again, both are far from exclusive).

Here is a short summary of  experience working at Upper Cretaceous excavation sites in the South of France (that’s around 80-65 million years old) namely in the Bellevue excavation site in Esperaza run by the Musée des Dinosaures.

First step is to find a place to dig.

Step 1.1: find something

Why along the road? It doesn’t have to be but it has two clear advantages: you can park your car next to it and it’s usually rich in fresh outcrops of rock (where you can find more fossils than in a crop field!).

Step 1.2: try again and again!

The second step, once you’ve decided that there might be something in the outcrop you’ve just explored, is to remove all the “annoying stuff”. To palaeontologists that obviously means all the wonderful fauna and flora and their associated environment (usually soil) that are growing above the potential fossiliferous site (how rude of them!).

Step 2: remove all the annoying stuff

Once you’ve removed the layer of living stuff, you can start the long and interesting part: hitting rocks with a hammer and a pike during the hottest days of summer.

Step 3: start hitting the rocks
Step 4: find something (hopefully!)

Finally, with a bit (a huge bit) of luck, you’ll find a fossil that was worth all this hassle.

Step 5.1: clean the fossil

Once you’ve found the fossil, the first step is to clean the surface facing you and start to build a trench around it in order to pour plaster over it and bring it to the lab. As you can see, paint brushes are useless here too: the hammer and the pike make ideal tools for the surrounding trench and an oyster knife and a smaller hammer do the cleaning jobs. Oh yeah, and a tube of glue. After around 80 million years, the bones get a bit fragile.

Step 5.2: clean the fossil… again!

The last step is to properly clean the fossil in the lab by removing it from all the surrounding rock. The best tools are mini pneumatic-drills and loads of patience. When all that is done, the palaeontologist can start to work on the fossil.

You can find more impressive pictures on the Musée des Dinosaures webpage.

Author: Thomas Guillerme, guillert[at]tcd.ie, @TGuillerme

Images: Thomas Guillerme and Sébastien Enault (with the kind authorisation of Jean Le Loeuff). Feature image: http://www.libraryofbirmingham.com/

What is(n’t) palaeontology like?

paleontology

After rereading Sive’s excellent blog post on what is a zoologist or at least what is it like to study it, I remember having a slightly similar difficulty in explaining my background in palaeontology. Reactions range from: “Oh… Palaeontology? That’s like the origins of humans and stuff?” or “So you go on excavations and find ancient Roman pottery?” to “Bheuuh, want another beer?”. What frustrated me is that none of these reactions are correct but neither are they totally incorrect (especially the last one!).

Palaeontology is not archaeology

Most people that have only a vague idea of what palaeontology is are usually not big fans of Jurassic Park and don’t know Alan Grant so they usually associate palaeontology with Ross Geller or Indiana Jones. Being not a big fan of TV series, I don’t know whether Ross is a good representation of the reality of life as a palaeontologist but I know that Indiana is not. Not even a little bit. He’s an archaeologist. That might be a nerdy detail for some but to understand what palaeontology is about, it is important to understand the difference. Even though both archaeologists and palaeontologists study the past based on what they find in the ground (and in books!), the time scales involved make the two disciplines impossible to compare. Archaeologists are mainly interested in human culture (they might find animal bones but they are usually the fragments of crafted objects). In contrast, palaeontologists are interested in the remains of life that occurred before human civilisation. Therefore we have two very different time scales here: from years to centuries or, at a push, millennia for archaeologists and from hundreds to millions of millennia (or billion of years) for palaeontologists.

Palaeontology is not about excavations

Palaeontologists do not excavate fossils, that’s a job for Oryctologists. Okay, I’m being picky with the terms here but, again, the distinction is important. Most palaeontologists are also oryctologists, meaning that they go into the field and do excavations as the basis for their scientific work (yeah, in the end, that’s not a cliché, one of the nicest parts of the job is field work!). However, not all palaeontologists are oryctologists (even though most are) and many oryctologists are not palaeontologists. Again, palaeontology is not only about digging up fossils and putting them in museums (contrary to what this song suggests), it is about the study of changes that occurred on our planet through deep time (geography, climate, etc…) and how they affected living organisms (evolution, extinction, etc…).

JP-Digsite

While we’re on the subject of oryctology, there is a huge public misconception about excavations. Most people that have seen Jurassic Park might think that, in the 90’s, one could just go into the field armed with nothing but a paint brush and happily stumble across a complete Velociraptor (Deinonychus!) skeleton which just had to be cleaned out from the surrounding layers of dust. This scenario would certainly make palaeontology way more straightforward and easy but it would also mean that excavations would be just boring routines where a hoover would do a better job than a naively enthusiastic undergrad student!

Even though excavation techniques are at least as numerous as excavation sites, the paint brush must be one of the rarest tools. Personally, I’ve tried things like hammering a cliff with a pike, shoveling dust and blocks of stone, digging in solid clay with an oyster knife or sifting tons of bags of sediments after diluting it in acid in a lab. None of these activities are similar to the restful act of flicking away sand with a brush (but they’re still a lot of fun!).

Palaeontology is not dusty

The two points above are understandably confusing for the general public because of the Hollywood image of palaeontologists, depicted as “adventurers, not really serious, but entertaining” (to translate a quote from Eric Buffetaut’s book “À quoi servent les dinosaures?”). One might think that other scientists would have a better understanding of palaeontology. However, even if they generally understand the discipline and its implications better than the general public: “Paleontology has a reputation as a dry and dusty discipline, stymied by privileged access to fossil specimens that are interpreted with an eye of faith and used to evidence just-so stories of adaptive evolution” (Cunningham et al 2014).

Thankfully, however, the discipline that studies traces of evolution has not escaped evolution of its own. The “privileged access to fossil specimens” has been replaced by either huge online databases (just one example and one other among thousands) or accessible and well-curated collections. The “eye of faith” has been replaced by X-Ray tomography, Surface scanners and synchrotrons; and the “just-so stories” are now replaced by integrative studies leading to a new vision of the history of life

Palaeontology is… great

The differences between a nerdy “Indianajonesomorph” oryctologist that knows all of the dinosaurs’ names by heart and a realistic palaeontologist are what makes palaeontology so interesting. More than the taxonomy, taphonomy, comparative anatomy and cladistic tools that palaeontologists use, palaeontology is about the idea that everything is constantly changing and that we live in just one fleeting moment in the vast history of life.

However, I still like the image of the “adventurers, not really serious, but entertaining”… As long as palaeontologists don’t take this image seriously themselves!

Author: Thomas Guillerme, guillert[at]tcd.ie, @TGuillerme

Images: Wikicommons

The Wakatobi Flowerpecker: the reclassification of a bird species and why it matters

Wakatobi Flowerpecker - Male

I posted previously about my PhD research studying bird populations from the tropical and biodiversity-rich region of Sulawesi, Indonesia. I am happy to announce that the first paper as part of this research has just been published in the open access journal PLOS ONE. To read the full paper for free, click here. This work is a collaborative effort from staff in the Department of Zoology in Trinity College Dublin and Haluoleo University in Sulawesi. Here, I’d like to discuss the wider importance of the findings of this study.

My current research focuses on bird populations from peninsular South-east Sulawesi and the nearby Wakatobi Islands. The main focus of this paper was to reassess the taxonomic status of a population of birds from the Wakatobi Islands (i.e. whether these birds represent a species or subspecies). The birds in question belong to the flowerpecker family (Dicaeidae); a group of small and colourful, arboreal passerines found from Southeast Asia to Australia. The Wakatobi birds were originally described as a separate species (Dicaeum kuehni) from those on mainland Sulawesi by the renowned avian taxonomist Ernst J. Hartert. However, for reasons that remain unclear in the literature, the Wakatobi birds were later reclassified as a subspecies of the Grey-sided Flowerpecker (Dicaeum celebicum) from mainland Sulawesi. Therefore we decided the Wakatobi populations were deserving of reassessment. From comparisons of plumage and morphology (that is, the measurement of various features such as a bird’s wing and bill), as well as estimates of genetic divergence and phylogenetic relationships between Wakatobi and Sulawesi populations, our results suggest the Wakatobi birds deserve to be recognised as a distinct species. We have therefore recommended the Wakatobi populations be reclassified as Dicaeum kuehni, a species found only on the Wakatobi archipelago and put forward the common name ‘Wakatobi Flowerpecker’.  For more detailed methods and results check out the paper.

“So what?”, you might say. Well, despite centuries of work from naturalists aiming to estimate the number of different species that exist or have existed on Earth (be they animal, plant, fungus, bacteria, etc) and further understand their evolutionary relationships, we still have a lot to learn! Therefore, this research adds another tiny piece to this enormous and incomplete jigsaw. Through a greater understanding of life on Earth we can attempt to answer some of the great philosophical questions, such as ‘Where and how did life start?’; ‘How and why do new species appear?’;  ‘Why has life evolved to become as it is today?’; and ‘How have we, as humans, come to be?’. Anyway, let’s be honest, who doesn’t enjoy learning of a recently discovered species or simply one they haven’t heard of before (be they as cute as the recently discovered olinguito or as frighteningly ugly as the goblin shark)? But the endeavour to discover species and classify and quantify the diversity on life on Earth brings us much more than entertainment and endless fascination, it also has very practical applications. Data on the distribution and conservation status of species are one of the major sources of information used to inform conservation policy. Therefore, as we are in the midst of an extinction crisis, it is vital that these data are accurate.

In order to maximise our understanding biodiversity, particularly in the remote and poorly known Sulawesi region of Indonesia, we require multi-disciplinary research. For example, take a look at Figure 1 below. On the left are a male (above) and a female (below) Grey-sided Flowerpecker from mainland Sulawesi. On the right are a male (above) and a female (below) Wakatobi Flowerpecker. They look very similar, right? This is true. However there are subtle but consistent differences in plumage between the species (again, see the paper for more info on this). Without the collection of detailed morphological data and the generation of genetic sequences, we may have incorrectly concluded that these make up just one species, when in fact they are morphologically distinct, reproductively isolated and genetically very different. This demonstrates the need for modern research, not just in Sulawesi, but globally, to employ integrative research, combining traditional comparisons of colour, size and shape with modern genetic and phylogenetic analyses.

Figure 1. Plumage comparisons-p18pjcggcs1dgo1ulm1sor9s214bc
Figure 1. A comparison of plumage characteristics between male (top row) and female (bottom row) Grey-sided Flowerpeckers (left) and Wakatobi Flowerpeckers (right).

Despite the knowledge that the Sulawesi region is home to a large number of remarkable birds that are found nowhere else in the world, it has remained relatively poorly studied. Furthermore, there has been a lack of integrative ornithological research in the area and very little genetic sampling. Therefore, it is likely that avian species richness for the Sulawesi region is underestimated and that numerous bird species are awaiting description. On top of this, Sulawesi’s biodiversity is facing major threats from a rapidly expanding human population and mass habitat destruction, among other things. Unless we can encourage more multi-disciplinary research within the region, we will likely fail to recognise evolutionarily distinct lineages and run the risk of losing them forever.

Our current findings inspire many further questions. For example, why have the flowerpeckers on the Wakatobi islands become so different to their close relatives on mainland Sulawesi? In other words, what are the evolutionary pressures that have driven the divergence of the Wakatobi Flowerpeckers? By investigating these questions, we hope to learn more about the evolutionary processes of speciation and adaptation to living on islands. As the Wakatobi Flowerpecker is found only on the Wakatobi Islands, the protection status afforded to the islands may require reassessment. Furthermore, considering one unique bird species has evolved on the Wakatobi, could there be more? Watch this space.

Author and Images:  Seán Kelly, kellys17[at]tcd.ie, @seankelly999

Mooching in Madagascar

I recently returned from a short stint of fieldwork in Madagascar. The purpose of our trip was to run some behavioural tests of echolocation in tenrecs but things didn’t exactly go according to plan. Therefore we had plenty of time to explore and experience some of the wonders of the 8th continent.

Here’s a few of our wildlife highlights…

Shower lizard
Our friend from the shower
Spider webs
Enormous spider webs which span an entire river bed!
Moth case
Case from a bagworm moth
Indri
Spot the Indri (like four year olds in panda suits..)
Tree frog
What a poser
Chameleon
Just hanging around
Camouflaged frog
Spot the frog
Red bellied lemurs
Inquisitive red bellied lemurs (Eulemur rubriventer)
Hemicentetes semispinosus
Tenrec in a bucket! Hemicentetes semispinosus

 Author and Images: Sive Finlay, sfinlay[at]tcd.ie, @SiveFinlay

Silence of the Tenrecs

Microgale cowani

I’ve been studying tenrecs for almost two years. I’ve read about them, watched video clips and handled hundreds of dead specimens. However, within that time I only met two live individuals, both of which were captive zoo animals. That’s all changed. I’m now well acquainted with a variety of tenrec critters. It turns out they’re a quiet bunch.

Just slightly excited to be holding a live tenrec!
Just slightly excited to be holding a live tenrec!

My supervisor, Natalie, and I spent two weeks in Madagascar working with a research team from the Vahatra Association led by Steve Goodman. The purpose of their trip was to conduct a disease transmission study in bats and small terrestrial mammals study at Ambohitantely Special Reserve, a protected, upland native forest north west of Antananarivo.

Ambohitantely forest surrounded by central plateau grassland
Looking down onto Ambohitantely forest; not a bad place to work…

We tagged along on the trip to run behavioural experiments to test whether there’s evidence for echolocation in the shrew-type (Microgale) tenrecs. Armed with a bat detector and an adjustable maze, my plan was to record the tenrecs’ calls as they move through their environment in search of a worm food reward at the end of the maze.

Our “experimental chamber”; the maze box (covered with material in the bottom right of the picture) set up in a shower cubicle!

I had envisaged many potential problems with the experiment. How would we be able to filter out interesting noises from background sounds? Would the noise of the animals moving around mask out the true vocalisations? I didn’t, however, foresee the problem with which we were faced; they didn’t make any noise whatsoever, zilch, not a peep.

Pockets bulging with tenrecs!

We tried multiple methods to coax some sound out of the furry creatures. The animals were kept warm in Natalie’s increasingly bulging coat pockets. We tried to entice the animals using juicy worms as proverbial carrots. We experimented with placing pairs of individuals in the box at the same time hoping to overhear some  tenrec chat. We also eliminated technical faults as a possible cause by testing out my detector on the bats flying around camp at night. All to no avail.

Microgale dobsoni; "I'm not going to produce any sound and you can't make me"
Microgale dobsoni; “I don’t want to produce any sound and you can’t make me”

I think they were holding out on us. The other, more experienced field researchers had heard tenrecs squeaking while foraging. The previous work on echolocation in tenrecs which inspired my experiments includes recordings of one species of Microgale so the animals are certainly not mute. I think our empty sound files are an unfortunate consequence of our experimental protocol. Existing research on possible echolocation in shrews and tenrecs used captive animals under highly controlled experimental conditions. We, however, were constrained by time and resources to an artificial experimental set up so it’s unfortunate but not entirely surprising that things didn’t go according to plan.

Still, the trip was far from wasted. Studying and observing living animals is just a tad more exciting than their museum counterparts and I now have enough pictures of tenrecs to last for a lifetime of presentations. We met some extremely interesting and knowledgeable researchers and we had the opportunity to work in a remote, beautiful and exotic place.

Furthermore, our failed experiments left time to go and explore other areas as tourists; expect our encounters with Indri, mouse lemurs, chameleons and enormous spiders to be coming soon…

Author and Images: Sive Finlay, sfinlay[at]tcd.ie, @SiveFinlay

 

Echolocating Tenrecs

Small Madagascar Hedgehog Tenrec

I’m going to Madagascar tomorrow.

I have all the essentials; insect repellent, tent, flat pack wooden box, bat detector, three metres of blackout curtain material… Not the most usual of packing lists admittedly but all necessary items for the trip ahead.

I’m going to study tenrecs; cute mammals which are the subject of my PhD. I’m interested in convergent evolution between tenrecs and other small mammals. So far I’ve been focusing on morphological convergence – work which has involved trips to beautiful museums and taming the dark arts of morphometrics. The primary aim of my research is to assess the evidence for morphological and ecological convergences among tenrecs and the mammals they resemble. Technically I could complete these aspects of the project without ever seeing or dealing with the live animals. But where’s the fun in that?! I’m also interested in behavioural convergences among tenrecs and other mammals, particularly reports of the abilities of some tenrecs to echolocate.

Some shrews produce echolocation calls by clicking their tongues. More recent work indicates that shrews seem to use these clicking calls primarily for navigation within their habitat rather than communication. Intriguingly, there is evidence that at least three species of tenrec; the lesser hedgehog tenrec, lowland streaked tenrec and Dobson’s shrew tenrec, can also echolocate. The animals seem to use their tongue clicks for navigation. The stridulation sounds produced by specialised spines in lowland streaked tenrecs and juvenile tail-less tenrecs have also been linked to having an echolocatory function but immobilising the spines doesn’t seem to affect the animals’ abilities to navigate by sound.

These early experiments are tantalising evidence of intriguing behavioural convergences among shrews and tenrecs. However, limitations of 1960’s acoustic technology and the ever so slight changes in standards of experimental practice (blinding animals with cement doesn’t go down so well with modern ethics boards!) mean that the study of echolocation in tenrecs is ripe for further exploration.

Hence my unusual packing list. My plan is to place wild-caught tenrecs within a box that can be converted into a maze of various layout and complexity (I’m extremely grateful to our super technician, Peter Stafford for making an adjustable maze which can be flat-packed for travel to Madagascar!).

image
Tenrec maze!

Using a bat detector, I’m going to record the sounds produced by the animals both when they’re “at rest” just in the empty box and when faced with the task of moving through the maze to reach food at the other end. I’m going to observe and film the animals moving through the maze, both in daylight and under red-light conditions in darkness (hence the blackout curtains) and record the sounds they produce as they move. The idea is to test whether the animals’ call patterns (structure/frequency of calls) changes as they navigate their way past an obstacle in the maze. Bats are known to modulate their call frequencies when they hone in on their prey or to navigate their way past obstacles. I want to test whether there’s similar call modification in tenrecs which would provide evidence that the animals are actually using their echolocation sounds for navigation. It would be fascinating to understand more of how tenrecs use echolocation and to test whether other tenrec species can also echolocate.

It all sounds quite straightforward but I’ve experienced some of the vagaries of fieldwork in the past and I’m anticipating many more problems to come. I’ve received advice and war tales from researchers who have tried to study echolocation in shrews only to be thwarted by problems of distinguishing the animals’ calls from background sounds or the noise of the animal’s claws on a wooden base. Similarly, the tenrecs may not want to cooperate with my idea of moving from one end of the maze to another. I’m hoping that a nice juicy earthworm at the other end will act as the metaphorical carrot but there’s no way to know until we actually try it out. Furthermore, it might be difficult to distinguish sounds that say “I’m scared of being in this box” from sounds that the animals are using for navigation. Similarly, since we have neither the option nor inclination to experimentally blind or deafen the animals we won’t be able to completely exclude the possibility that the animals are using other sensory cues aside from acoustic navigation.

Even still, I’m hoping to get results which demonstrate the range of calls produced by tenrecs and which provide clues into how the animals use their acoustic behaviour to their advantage. Echolocation has involved independently in different animal lineages. Most interestingly, there is even clear evidence for convergence at the level of genetic sequences.  Hopefully the data I gather over the next few weeks will add to our understanding of this fascinating story of convergence among tenrecs and other mammals.

And maybe we’ll spot a few lemurs on the way…

Author: Sive Finlay, sfinlay[at]tcd.ie, @SiveFinlay

Image Source: S. Finlay

 

Kenya- A Summary through the vegetation

Campsite at Ol Pejeta, with Acacia xanthophloea in the background.
Campsite at Ol Pejeta, with Acacia xanthophloea in the background.

During the first week of November I travelled to Kenya to help out on the Tropical Field Ecology course, run by Ian Donahue in the Zoology Department.  Final year students from Zoology, Environmental Sciences, and Plant Sciences attended, and I was the postgraduate representative from the Botany Department.  While I should under no circumstances be considered a true Botanist-I study plant-animal interactions, and my botanical skills are mediocre at best- I did my best to learn about the amazing tropical flora of this region.  I’m sure others will write about the trip in detail, but I thought I would summarize our experience using the dominant or interesting plants we saw in each place we travelled.

Day 1&2- Arrive in Nairobi: After spending the night in the United Kenya Club, we awoke to a 5 hour drive north to Laikipia County.  Along the way the most striking plants were ornamental and known to a number of the students already- for example, colourful Bougainvillea was visible from quite a distance, as were the beautiful flowering Jacaranda trees- neither of course are native to the region.

Day 3-Ol Pejeta Conservancy, Laikipia County: We camped for the next two days in Ol Pejeta, and although we experienced quite a bit of rain, it was one of the most beautiful places I’ve ever seen.  The campsite was on the river and surrounded by Acacia xanthophloea, known to the locals as “Yellow fever acacia” for its medicinal properties.  It has a yellow-green bark which makes it quite distinctive.  On game drives we saw a lot of scrubby shrub species, none in flower.  It was difficult to identify many of the species in the conservancy but we were told many of them belong to the genus Euclea.  We also got our first glimpse of Solanum incanum but more on that later.

Solanum incanum at the Chimpanzee sanctuary in Ol Pejeta
Solanum incanum at the Chimpanzee sanctuary in Ol Pejeta

Day 4- Nakuru: Compared to Ol Pejeta the flowering flora here was a breeze to identify! Although a lot of it comprised invasive species, such as Lantana and Datura species, and of course the conspicuous Solanum incanum (also known as Sodom’s Apple).  S. incanum gives the management at Nakuru serious trouble, growing uncontrolled in areas that are over grazed or disturbed by humans.  In addition to the invasives we saw a lot of Leonotis mollissima and identified a lovely shrub called Tarchonanthus camphorates from its camphor scented leaves.

Day 5-11-Baringo County: And finally, after quite a lot of driving (during which we saw some impressive Euphorbia candelabra specimen), we arrived in Baringo County.  Our first day here we went for a hike at Lake Bogoria, and spotted two species of interest.  First, the indigenous Adenium obesum, or Desert Rose.  Some of the students carried out their mini-project on the nectar secretion and flower visitation of this species, and found nectar volume varies with time of day.  Second, we saw Salvadora persica, known as the “toothbrush tree.”  Our local guide told us people chew the twigs to promote dental hygiene.  Throughout the county, two new species of Acacia were also evident- Acacia tortilis (The Umbrella Thorn, accurately named after its shape) and Acacia mellifera.  Women in the area highly value A. mellifera because the honeybees they keep apparently favour it for making particularly sweet honey.  And finally, one cannot forget to mention the damaging invasive Prosopis juliflora.  Native to Mexico and Central America, it was introduced to try and control soil erosion and now has spread throughout the county.  It is difficult to remove as it can regenerate from the roots, and is not particularly useful as fuel, food for livestock or fencing.

Adenium obesum, Desert Rose at our campsite in Baringo, Robert’s Camp
Adenium obesum, Desert Rose at our campsite in Baringo, Robert’s Camp

This description is simply the most obvious vegetation we saw on the field course.  The diversity of flora and fauna was overwhelming and I think the students, demonstrators, and staff alike were impressed and awed by the environments we were fortunate enough to experience.  Kenya is truly an amazing place!

Author and Picture Credits;

Erin Jo Tiedeken, tiedekee[at]tcd.ie, @EJTiedeken

Sulawesi Bird Expedition 2013

Beach

Ah the summer, how I miss it! In mid-June I departed (on the horrendously long journey) to the beautifully sunny, tropical islands off the south-eastern coast of Sulawesi, Indonesia. No, I wasn’t on holidays; I am fortunate enough to call this part of the world my study site. During the six week visit, I aimed to gain further behavioural and ecological data on a number of bird species as part of my current PhD project – for more specifics on that see here. I am even more fortunate to be able to carry out this research with the financial and logistical support of Operation Wallacea, an internationally renowned conservation charity that works with researchers from all over the globe, from a variety of different disciplines. As part of this support, I work with students and volunteers in the field, helping them to design effective dissertation projects and field methods. This year I was joined by five students (as opposed to two last year) from a variety of universities in Ireland and the UK.

From the first day it was back to the usual diet (mostly consisting of rice) and routine: up at 4.30am for breakfast and out surveying by 6am. These surveys consisted of walking 1km transects through scrub, farmland and/or forest edge collecting data on my target species’ diets, competitors (via agonistic interactions), social habitats, courtship and breeding, as well as their foraging and flocking behaviours. In the evening we would establish new transects and then get stuck into data entry at night. This routine makes for days that are long and tiring but hugely rewarding. Watching birds so closely allows you to gain intimate insight into their lives and observe some fantastic interactions, such as family groups of Lemon-bellied White-eyes preening each other and pairs reinforcing bonds with gifts of food. You also see how tirelessly and (sometimes) viciously males will fight off other males in order to retain their mates and, therefore, mating privileges, as we saw in the beautifully adorned Olive-backed Sunbird. Spending so much time in the field, you come across a great variety of other wildlife including troops of macaques, the strange bear cuscus, giant monitor lizards, pythons, huge fruit bats and hairy and multicoloured caterpillars that you never touch, to pick out but a few.

An adult Lemon-bellied White-eye returning with food for its chicks
An adult Lemon-bellied White-eye returning with food for its chicks
A beautiful fruit bat relaxing in a banana tree
A beautiful fruit bat relaxing in a banana tree

I’m delighted to say that data collection went exceedingly well for the students and myself – that is, when the weather was on our side (we had a week of non-stop rain while Ireland and the UK were experiencing a heat-wave; typical!). We surveyed five islands in total and got some superb behavioural data on each of our five target species. While managing a large group like this was difficult and tiring at times, it was a great experience and the students were a great bunch really. In the company of the assistants and students on the project, as well as the many other members of staff, students and volunteers from other projects, with their combined wealth of experience and knowledge, it was fantastic to share ideas, brainstorm and discuss current/potential future projects.

The biggest highlight for me was catching up with the elusive ‘Wangi-wangi’ White-eye, a bird we know very little about. It was touch and go for a while, and I was getting quite worried to be honest, but eventually we got excellent data on their flocking and feeding behaviour and who they compete with, directly and indirectly. Between us, the group racked up a number of new bird records for the islands and saw some spectacular species such as the Great-billed Kingfisher, Rainbow Bee-eater, Yellow-eyed Imperial Pigeon, Great-billed Parrot, Yellow-billed Malkoha and Red-knobbed Hornbill. Phwoar!

The stunning Yellow-billed Malkoha, a Sulawesi endemic
The stunning Yellow-billed Malkoha, a Sulawesi endemic 

Sadly, this summer was the last of my field trips to Indonesia as part of my PhD project. I enjoyed it immensely and, for certain, I will be back. I am grateful to Operation Wallacea for allowing me to be involved in such a programme and I hope that they will continue to expand into more areas of this highly unique and understudied part of the world that is full of discoveries yet to be made.

Author and Photo credits:

Seán Kelly: kellys17[at]tcd.ie, @seankelly999