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domingo, 26 de junio de 2011

Nicknames, fake birds, and funny ferns

Over the last 2 weeks there have been some exciting, and sometimes amusing, events. Greg Goodfellow continues to progress with his investigation into aggression, territorial, and mate guarding behaviour among white-rumped tanagers (Cypsnagra hirundinacea). He has designed a number of dummy birds whose visual presence will be combined with the vocalisations playbacks he conducts. However, like many things, building dummy birds is a learning process which needs practice. Greg’s first dummy was a giant white sock filled with sand with two pieces of paper (wings) stuck to the sides. Thankfully his current dummies are much better and more lifelike. He has also now located and recorded 4 different groups so intergroup comparisons are now a possibility.
Georgina Snelling has had a good first week. She is a typical botanist – spots many things a zoologist would obliviously walk straight past. I think I’ve learnt as much as she has this week!
After exploring the different habitats in the reserve she became interested in, what she thought, the unusual array and distribution of fern and moss species. She began finding these organisms in areas she would never expect, and vice versa. This confused her. So she has decided to un-confuse herself by addressing some of these issues through her research project. Georgina will examine the abundance and distribution of fern species within the reserve, and, importantly, why there are differences in their distribution. She will incorporate many aspects, from sunlight exposure to nitrogen levels in the soil, and will collect her data in a systematic way through the use of quadrant sampling.
On a separate note – I showed Georgina a strange bulb-like plant in the dry forest (monte seco) that has only become visible in the last few months. She found it as strange as I and then proceeded to make it her mission to find out what it was. She didn’t. However, I mentioned it in passing when I was talking with Para la Tierra Project Coordinator Karina Atkinson, and she had some good news. One individual that was among the conservation guests we had here a couple week ago also noticed the funny plant/flower/bulb. We were very happy to hear that not only is this the first documented occurrence of this species in this region of Paraguay, but only the third record in the whole of Paraguay.
So it is good to have a botanical intern with us here. Not only will it add diversity to our group but it will also broaden the information Para la Tierra produce on these natural habitats.
Aimme Oxley is driving ahead with the construction of gradient trapping lines in the Atlantic forest. With the help of our typically excellent volunteers, Jaime and Claire, she has already completed over 50% of her lines. Hopefully she will be able to start trapping and collecting data next week. However, although very hard work, I think the three of them have had fun with this process (partly due to their positive attitude towards this task). Hand blisters, insect bites, and sore muscles have all been laughed over, and the issuing of trail-cutting nicknames has been introduced. So these days the Atlantic forest trail cutters are known by such names as ‘slasher’, ‘hacker’, and even ‘the Don’.

Behaviour among Cyanocorax chrysops (plush-crested jays)

Data collection and study on the behavioural repertoire of these birds continues to go well. I have recorded new behaviours to add to the growing ethogram – allogrooming, dominant and submissive behaviours and vocalisations, to name a few. Much to my frustration they continue to be wary of my feeding stations. It’s a shame the same cannot be said for their closely related cousins the curl-crested jays, who ive caught enjoying the offerings several times. However, although frustrated, the fact that the plush-crested are not easily fooled add to the current opinion that these birds are very intelligent, and hence probably have a complex social system.
I have taken a further step in the first phase of this study. Along with the standard ethogram, I will now offer a ‘flow ethogram’. Flow ethograms are the natural next step from the first documentation of a species behaviour. Instead of leaving the documented behaviours separate from each other a flow ethogram offers behavioural sequencing, i.e in what order and in what combination are behaviours usually observed? These steps are necessary to pave the way for further, more complex study, not only on this species but also for comparisons to other closely related species.

Social and ecological factors among Clyomys laticeps (broad-headed spiny rat).

As I said in my last posting, I have taken the decision to incorporate burrow traps as well as ground traps in order to record certain morphological and behavioural aspects among these rodents. I carried out some pilot work to see how feasible inserting burrow traps would be. Thankfully the process was fairly simply to carry out. Therefore I will be setting these traps in all the new or recently used burrows that are within my study area.
After consulting with our botany intern Georgina it seems like we may be correct in our theory as to why these animals seem to burrow under a particular scrub. From a botanical perspective it appears the structure and appearance of this scrub (very leafy) suggests it is accumulating and holding more water than other botanical life on the Cerrado. Therefore it would make sense that clyomys are utilizing one of the few water sources in their habitat. However, this is still an assumption and as scientists we need to test our assumptions. So I think it’s time for me to get the shovel out and start digging!

Best wishes,

Luke

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