Fieldwork Archives - Page 3 of 3

02/05/201403/05/2014

Silence of the Tenrecs

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!

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.

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

28/03/201426/03/2014

Echolocating Tenrecs

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!).

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

25/11/201315/11/2013

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

14/10/201330/09/2013

Sulawesi Bird Expedition 2013

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

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

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