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News from the forest 2

Introduction

Dear funders and supporters,

With this second newsletter I hope to inform you on

the progress of the study on the population density

of Callicebus oenanthe in Ojos de Agua, a

conservation concession in North-eastern Peru.

The largest part of this study is now finished: we

have collected all our data! I have been back in the

UK for almost two weeks, have drawn all the

triangulation maps and had the first meeting with my supervisor Prof. Catherine Hill. Analysis

of the data and the writing of the dissertation will start as soon as I have finished this

newsletter.

In this newsletter I will inform you about the last weeks of data collection, expose some

interesting questions I will try to answer in my dissertation, show you some more pictures

from the field and inform you about the very first attendance to a conference where I will

present our work.

Finishing data collection…

… proved to be slightly harder than expected. For a dry forest in the dry season we have

had an enormous amount of rain. Even the villagers of Pucacaca were surprised by the

amount of rain this time of year. And as you might know: titi monkeys do not sing when it

rains. But as soon as the rain stopped, the heat kicked in. Temperatures over 35° C were

not an abnormality. Then there were some logistic problems: motorcars breaking down,

In this newsletter:

Introduction

Finishing data collection

What happens next?

Upcoming events

Pictures from the field

Acknowledgements

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looking for replacement transportation and motorcars not being able to drop us off at the

most convenient points because roads had turned into miles of sticky mud.

Due to these minor setbacks we got slightly behind on schedule and by the time I had to

catch my plane back to the UK we still had three listening areas to go. Luckily we found the

perfect solution…

Over time the people of ABOFOA had grown more and more involved in the research project

and were very motivated to help me collect data at the last three listening areas. After

spending 6 months with Proyecto Mono Tocón, Jaime’s time to go back to Spain had come.

It was up to Eduardo to finish the study together with two people from ABOFOA. Felipe,

president of ABOFOA, and guide Joaquin offered to help out. So the fifth trip was the trip in

which we trained Felipe and Joaquin. Both turned out to be very eager and extremely

precise in estimating distance and angle of a vocalisation. At the end of their training I felt

very confident that they are able to collect these data themselves and train their fellow

ABOFOA associates. Also, non-profit organisation Amazónios por la Amazonía (AMPA) had

donated two GPS devices to ABOFOA. So while Jaime and I spent some afternoons

entering our data into the netbook and pairing up the vocalisations that could possibly

triangulate, Eduardo went on a few trips with president Felipe in order to teach him the

basics of using a GPS.

At the end of the fifth trip, the last days in the forest for both Jaime and me, we held a

presentation on our study for the people of ABOFOA and the villagers of Pucacaca. We

were unable to show them any results, but we explained in detail what we had done, taught

them more about the Critically Endangered titi monkeys living in their forest, showed pictures

of all the animals we had seen and a film of the titi monkeys calling. At the end I thanked

them in my best Spanish for allowing us to be in their forest and their homes.

During one of our first days in the forest, field guide Tiberio had cut me a walking stick,

because I had some trouble getting up the steeper parts of the mountain. I have had that

stick with me every single day and carved into it during some spare hours. Felipe asked me

if they could keep the stick. They wanted to hang it on the wall in their office, together with a

sign with my name on it. I feel like a celebrity! But joking aside, I am glad that our efforts and

presence have been so very appreciated by the people of ABOFOA.

I felt sad having to leave the villagers of Pucacaca, who had taught me about their way of

life, cooked us their traditional meals and who came to see us as part of their family. I will

also miss working with the people of ABOFOA, Proyecto Mono Tocón and Jaime and

Eduardo. Their motivation has been an inspiration to me. Most of all I already miss the

peace and quietness of the forest in the afternoon, and the beautiful sounds of monkeys,

birds and insects during the early and late hours of the day.

What happens next?

The first part of the analysis consists of drawing maps with triangulations. By matching up

vocalisations from all three listening points that occurred around the same time, I hope to

see that some of these vocalisations turn out to be from the same group, and thus show

triangulating lines on the map. Following this, these data will be entered into the program

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Quantum GIS to get the exact coordinates and a map that looks more presentable than a

map drawn by hand (Fig. 1). However, we can’t do without our hand drawn maps, because

the software cannot take into account the time at which the vocalisations started; an

important factor for matching up the vocalisations from the three points. Then, by the use of

a formula (which I will elaborate on in the final report), the total number of Callicebus

oenanthe groups within Ojos de Agua is calculated. Last, with the statistical software SPSS

it is possible to use a t-test to look for any significant differences between population density

in primary and secondary forest and edge versus non-edge areas.

Figure 1. An example of a triangulation map in Quantum GIS.

While drawing the triangulation maps back in Oxford I noticed that some points that I

expected to triangulate, did not. Also, some of the points triangulated much further away

from us than any of us had estimated. I will have to dig into the literature to find an

explanation, but things I will consider are:

The direction the monkey is facing while singing.

The direction the observer is facing when they hear monkeys singing.

Factors in the landscape affecting the directionality of sounds.

The kind of vocalisations used: there are differences in acoustic properties of each

type of call.

Many of our observations of Callicebus oenanthe co-occurred with sightings of Saguinus

fuscicollis. They were not necessarily in the same tree or around at exactly the same time,

but I think I can safely say that whenever we saw titi monkeys, it was highly likely that we

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saw saddle back tamarins within the same 50 meter radius within a timeframe of

approximately 10 minutes. I will examine the literature to see if:

These interactions have been seen before (a definite yes!);

What explanations researchers have given to this co-occurrence;

What possible explanations there could be for this behaviour in Ojos de Agua.

While analysing the data, we have to keep in mind that the many rainy days and presence of

large fires, alongside men with chainsaws and bulldozers deforesting the area in the valley

may have affected our data.

Achievement of goals

I can proudly say that I am well on my way to achieving the goals I had set for myself and

the study. We have trained the people of ABOFOA in using the methods for triangulation and

gathering data on tree density and in the use of their newly acquired GPS units.

Data collection has been completed successfully. Methodology did not change much while in

the field, but our research questions had to change due to inaccessibility of parts of the

terrain and weather conditions. After analysis I hope to be able to provide both Proyecto

Mono Tocón and ABOFOA with numbers on the population density of Callicebus oenanthe

in conservation concession Ojos de Agua. And perhaps this study can tell us something

about the habitat preferences of the species.

This study has been an important part of my development as a young researcher. I now

know how to keep myself standing (both physically and mentally) in mountainous terrain, as

team leader and as researcher who’s plans never quite work out the way you had in mind

before you entered the field. I have enjoyed every second we spent in the forest. It was a

pleasure sitting in the forest, listening to the titi monkeys singing and at the same time being

visited by saddle back tamarins, hummingbirds (not so shy as they seem!) and other wildlife

(even dogs from hunters!).

Upcoming events

On the conference of the European Federation of Primatology (10-13 September, Antwerp,

Belgium) I will present a poster of this study. The poster presentations will take place on

Thursday 12 September, from 16:10 until 20:00.

I have really enjoyed the collaboration with ABOFOA, but unfortunately they will not be able

to read my dissertation as they don’t speak or read English. Therefore, I will translate my

poster into Spanish and ask Proyecto Mono Tocón to print it in Moyobamba with the leftover

money from the 6th expedition. They can hand the poster to ABOFOA when they go to

Pucacaca for their conservation classes with the local kids.

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Pictures from the field

Figure 2. Trouble in paradise…

Figure 3. Joaquin learning the ropes of the trade.

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Figure 4. ABOFOA president Felipe writing down his compass bearing. Figure 5. Joaquin and Felipe taking tree measurements.

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Figure 6. Little joys of the jungle: coconut water after work! Figure 7. Anteater spotted by Jaime at one of his listening areas.

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Acknowledgements

This study would not have been possible without the generous support of: