This video has been made with a drone, owned by a colleague from the Smithsonian Tropical Research Institute, the institute with which I collaborate in Panama. This is basically an aerial discovery of my fieldwork site. My bat model species roost in the houses of this village - all the data from my PhD is coming from there...Enjoy!
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Back to Germany for a little while. I am back to my survival analyses using the mark-recapture data of my bats.
A lot of programming is required to shape the data the way I want. For the end of the month, I have to finish the preparation of a poster for the evaluation of my doctoral school. I will update it on the website when ready! And always as a parallel task, I am taking care of the logistics for fieldwork, by wrapping up last season (finance report) and preparing the season to come (travel preparation, material order). Back to the field November and December! Good news for this beginning of the scholar year, the paper about project I was involved in during my master has been published! In a few words, we studied the second biggest genus of Mammals - the bat genus Myotis - to learn about their evolutionary history. We used DNA and models to learn the "genealogic tree" of these bats and estimate their biogeographic origins. I stayed a short month in Panama this summer – from mid-July to mid-August. The priority was to catch all the colonies we work on – more than 20 nights of catching for a total of around 300 bats. Many new bats have been transpondered and I have collected a lot of DNA (relatedness analysis) and feces samples (virus and diet studies). The highlight of the stay was the catch of 96 bats in one night. The catch started at 6PM and we finished processing the bats around 6AM.I had a small army of people from the batlab to help me – thanks to Teague, Basti, Julia, Sebas, Michelle, Toni, Santi, Dallas…
Unfortunately, three of the roosts with automated monitoring systems were abandoned (probably due to house renovation) but we installed two other automated monitoring systems. I also had the opportunity to present my PhD project to the scientific community – good practice with a lot of interesting questions. In addition, I helped Sebas for a parallel project. As a pilot study for his master thesis, we equipped these bats with heart-rate and temperature transmitters. The bats were kept in captivity and video-taped. This preliminary data will help understanding the relationship between heart-rate, temperate and clustering prevalence. My fieldwork season is over but Sebas will stay until early September to operate more trials and continue this project in November-December, when we both go back for a new fieldwork season. I am in the starting-blocks for a new fieldwork season in Panama. I will fly to Panama mid-July and stay until mid-August. My goal for this season is to catch all the colonies already surveyed in the previous fieldwork seasons - especially to collect DNA samples and equip non-marked bat with a subcutaneous transponder. This transponder can be scanned either manually (hand-held transponder reader) or automatically (automated transponder reader at roost entrance). This method is very useful to obtain data on dispersal, group composition and also survival.
A german Master student will help me for the catching and removal of bats from the nets. In parallel, this assistant will conduct some captivity experiments for his master's thesis. His project will focus on heart-rate and temperature to better understand metabolic rates of tropical animals. This should be the last but one fieldwork season of my PhD, the last one being planned in November-December. I will then have one year and a half to go in the lab for my DNA samples, analyse the collected data and write my PhD thesis. We have been tracking two species of bats in the last weeks.
For Teague's project on information transfer, we tracked Uroderma bilobatum, a small leaf-nosed bat eating figs. During 10 days, we tracked a handle of bats from 7PM to 5AM to learn more about their foraging grounds and see if the bats were foraging together. Two of our bats seemed to forage at the same fig tree but we need additional studies to prove it. In parallel, we tracked a roost of 11 Molossus molossus - the model species of my PhD. The idea of this tracking session was to assess the prevalence of group hunting in this species. Unfortunately, all the collars with the transmitters were removed after 2 days. We moved on to additional tests of collars in captivity but we could not design a collar that would stay long enough on bats. The tracking session of Molossus molossus is cancelled, we are now focussing on data collection at roosts and also analysing data. It's been already more than a week I am settled in Gamboa for my third fieldwork season of my PhD.
I am accompanied with Matthieu Ménage, a french bat guy, to help me in the field. We had a busy program in the past days with several nights of catching and transpondering individuals of Molossus molossus in different colonies. We have also installed two more automated systems to monitor automatically bat activity with Pit-tags (individual use of roost, emergence and return times, weight gain). The more recent program was focused on collar testing. Usually, we glue radio-transmitters on the back of animals. However, this procedure is not ideal as Molossus molossus can remove the transmitters with their feet and also scratch off their fur. We are now developing, with tips from Teague, hand-made collars to glue the transmitters on. We have realised tests on captive individuals, kept in baby tents for a few days and hand-fed by meal-worms. The design of the collars is promising but requires further tests. I'm going back next week for a third fieldwork season in the village of Gamboa Panama. Program: to continue data collection on my doctoral model species: Molossus molossus. And a field mission requires a bit of organisation !
As with all trips, I organize for me and my assistant the housing and transportation (plane, train, taxi ...). Together with my french assistant, we will live in an apartment provided by the host institution, the Smithsonian Tropical Research Institute. These homes are located in the village, near my roosts of bats. To complete my research legally, research permits for sample collection (skin, guano) must be written in Spanish and sent to the Panamanian authorities before verification. When my fieldwork season comes to an end, I will send a report of my fieldwork season and ask for an export permit to bring back to Germany the samples collected. And to complete the organization for the field, preparation of material is essential. Checking nets, preparing telemetry equipment, electronic testing, preparation of materials for sample collection ... the list is long! And before I go, I am working on my fieldwork program to plan the 11 weeks in the field. Catch sampling, radio-tracking ... More news when I'm on the ground! For my Phd fieldwork in Panama, I use a wide variety of tools to measure, to transponder and to sample the bats I catch, often with help from fieldwork assistants or some colleagues. I use generally 7 tools, described here and shown on the photo below. 1. The first tool is a scale, used to measure the weight of the bat (placed in a soft clothed bag). This feature gives a good idea about the age of the bat or if it has eaten. For examplen, my species weighs around 10g and can come back from foraging weighing 3-4g more. 2. The second tool is a calliper, used to measure the forearm length. This feature is often used as an help for species determination. 3. The third and fourth tools are a transponder needle mounted on a transponder injector. The needle contains the transponder that will be quickly injected under the bat skin of the bat. This is a sensitive operation but I trained and I process quickly. The transponder - with an individual identification number - will be injected once and will last for the whole life of the bat. Once the transponder is inserted, I check the number with a hand transponder-reader. 4. To sample DNA, I use a biopsy wingpunch. This tool consists of a 3mm-diameter metal ring mounted on a plastic pole. The DNA is sampled on the wing membrane, the "wingpunch" is then stored in a small tube of ethanol. The sampling on the wing membrane is optimal because this body part contains a lot of DNA and the healing really quick (around 2 weeks). Another story starts after for exportation of the samples, extraction of the DNA and of course the analyses... Thanks to Hyuen-Ji Lee for the picture :).
PS: All catching and sampling procedures are realised with permissions from the Panamean authorities. Last week was pretty intense with three different meetings!
The first meeting was my PhD commitee with my PhD advisors. One year after the beginning of my PhD, this meeting is intended to talk about the progress, identify the weaknesses and discuss about the program for the following year. Principal advice (useful for me but every student in general) - don't neglect the reading of papers and books... With all the other tasks (fieldwork, logistics...), it can be easily set aside. The second meeting was a brain huddle - a sort of brainstorming. With colleagues from the Max Planck Institute for Ornithology, we discussed about the data from the automated balance systems I have installed in Panama. The discussions helped me to get interesting tips about the way to look at my data and extract the essential information. In the next weeks, I will try and move forward with these automated analyses To finish, the third meeting was about the tracking session that will occur in Spring 2013. This fieldwork session will combine tracking of Molossus molossus and Uroderma bilobatum to understand the social foraging of these two species. The meeting was intended to talk about the methods and logistics. A blogpost (at least) about that next Spring :). A year has passed since I have started my PhD.
A lot of my time and energy went into this fieldwork season (mid-March until end July) to catch and transponder some bat colonies of my model species - Molossus molossus - in the village of Gamboa in Panama. After numerous hours of wood cutting and video check, I managed to instal automated balances that are monitoring bat activity thanks to their transponders. A contact in Gamboa is sending me the data by e-mail on a weekly basis. And my current program for the weeks to come is to try and extract the best information from this great source of data. I am also reading and writing to move forward on my PhD introduction – in parallel to fieldwork organization for the session of November-December (6 weeks) and the big tracking session in Spring… Stay connected! |
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