Today was another fantastic day in the field. Our RFID team caught 9 hummingbirds and put tags on most of them. We can now test out our readers in the wild to see if we really can record hummingbird movements. Evan and Bridget are hard at work on a feeder design that will maximize the chance that hummingbirds will activate the readers (and check in at our sites).
We have also been working on an interesting problem that we stumbled across a few years ago when doing a pollination experiment with a tropical flower species (Heliconia tortuosa). Human pollination is supposed to be a great baseline for ‘perfect pollination’. You can use this as a comparison to see how much less natural levels of pollination might be – due to bee declines, habitat loss or any number of factors. Our problem was that when we tried to artificially pollinate Heliconia, it didn’t work…at all. Hummingbirds, on the other hand, seemed to have no trouble; about 40% of the flowers visited by hummingbirds show signs of eventually producing fruit (pollination is required to do this). So, we’ve been designing a series of scientific experiments to find out what hummingbirds might be doing to make the flower fertile. I will tell you more about these later, but for now, look at the video and give us your ideas. What do you notice about the way the green hermit hummingbird visits the flower?
Here is a video: http://www.youtube.com/watch?v=OrINYjD3tN8&feature=youtu.be
Species of the Day: Violet Sabrewing! This is my favorite hummingbird species. It is the largest hummingbird around here, weighing about 12 grams (our Anna’s hummingbirds are about 3.5 grams). Unfortunately, this photo doesn’t do it justice at all. In flight, its throat (gorget) flashes much brighter purple.
I thought I’d start this blog by introducing myself and the rest of the hummingbird team a bit. Over the next few weeks, the whole hummingbird team will be sharing their experiences in Costa Rica (you won’t have to hear from just me). I’m Matt Betts, a Professor of Landscape Ecology at Oregon State University. What is landscape ecology? Well, ecology is the study of life and its interaction with the non-living environment. Landscape ecology does this, but considers both small scales (e.g., a single bird-flower interaction) and large scales (e.g., many patches of forest, each surrounded by agriculture). Landscape ecologists often try to ask whether large-scale patterns (e.g., the size of forest patches) influence important processes such as how well animals survive, have young, pollinate and spread seeds around. If you like plants, animals and think about their conservation, being a landscape ecologist is a great job.
Other members of my team include Adam Hadley, who is a postdoc at OSU and has studied hummingbirds for his PhD for 4 years. Adam is an excellent scientist and fantastic athlete – a great combination in this line of work (he had to run after hummingbirds through the jungle for some of his PhD work so that he could track their movement). Sarah Hadley, Adam’s wife, is my PhD student and has been working down here for 3 years as our main hummingbird bander. She is extremely good at handling birds (she’s done it for over 10 years) and is the only one of us (so far) to speak Spanish well. Needless to say, the project would collapse without her logistical brain. Evan Jackson is a first year graduate student also working on the project. He is the one who is testing the use of RFIDs (see Jan. 25th blog) to track hummingbird movements. In addition to working out the complicated electronics of the readers, Evan is also a master at moving through jungle quickly. This year, Bridget Guildner, a freshly minted undergradate student from OSU has also joined us. She has been helping us in the lab with the design of some other special computer-based tools to do hummingbird research (more on this later). She is by far the most tech-smart person in the group.
Every few days in this blog, we’ll be keeping you up-to-date on our work and on some of the beautiful and often strange things we see in the jungle of Costa Rica (we call this ‘the species of the day’).
Today’s species of the day is a Preying Mantis! This insect species is about the size of my hand and has amazing camouflage – its abdomen looks like a leaf (complete with bite out of it). We found this around lunch today. It jumped onto Sarah’s camera and then her face while we were taking photos. The amazing thing about the tropics is how rarely you see the same species twice. I’ve never seen this one before – it might be years before I do again.
Success! Our RFID tag readers work! It turns out that our new RFID tags are on a slightly different frequency to the ones we piloted last year (basically they communicate in a different language). So, the readers work with the new tags. Today was a very good day to be a field biologist. We got up at 5:15 am, loaded up our back-packs with batteries (packs weighing about the same as an average grade 5 student), our hummingbird banding gear, hummingbird traps and nets, and the readers of course.
The jungle hike into our hummingbird capture site
It wasn’t a very long walk this morning – only about 20-30 minutes down the Rio Java trail in the jungle reserve. We had ‘mist-nets’ set up by 6:30 (mist-nets are like gigantic hairnets (12 x 2 meters: 32 x 6 ft) that we string between two bamboo poles in hopes that a hummingbird will accidentally fly into it and get caught). Sure enough, by 7:00 we had caught five green hermits (one of our study species). So that we can recognize these birds in future years, we put tiny metal rings on their legs. We also put a small dab of nail polish in their heads so that we can recognize them through binoculars in the coming weeks (this falls off when they grow new feathers). Also, we attached the RFID tags so that when a bird goes near our feeders, we can tell who they are and when they visited without even seeing them!
A green hermit hummingbird (Phaethornis guy) with RFID tag.
We also put up 5 RFID readers within 100 m of where we captured the birds. The plan is to gradually expand this reader network outwards so that we can measure how far each individual travels in a typical day.
Here is a photo of one of our birds with an RFID tag. We test the tag by putting the bird through the antenna of the RFID reader. We then let the bird go. So that the bird doesn’t get too stressed and energy low by being captured, we give them some sugarwater for the journey. Sometimes they drink so much they have trouble taking off from our hands!
Pink nail polish on the head allows us to ID them through binoculars
We finally arrived at Las Cruces Biological Station yesterday after about 20 hours of travelling. Only about 8 hours of actual flying time, followed by a 5 hour drive south from San Jose to our field station. Costa Rica is known for its terrible roads (its hard to read a tour book without seeing complaints about massive ‘craters’ even on the Pan-American highway. The Government apparently reasoned that they would prefer to pay for education than roads and a military (Costa Rica doesn’t have one – sort of a neat idea to reduce a deficit eh?). But we were amazed to find that at least ½ of the road between San Jose and San Vito has been paved, which made for a smooth 3 am arrival rather than the anticipated 5 am.
As soon as we pulled up, we heard kinkajous in the treetops near our research cabins. Kinkajous are small nocturnal tree-living mammals related to raccoons and coatis (but cuter most would say). They also have some neat ‘super powers’: prehensile tails that allow them to grip branches (using only the tail). They wrap these around themselves at night to stay warm. This species can also turn its feet completely backwards which means that it can walk equally well backward and forwards along tree branches.
We spent yesterday getting our field and lab gear ready (hummingbird banding equipment, microscopes – for looking at pollen tubes [more on that later], radio-frequency identification devices [RFID; for monitoring hummingbirds – again more on that]. In total, we brought about 1 ton of equipment down (we calculated 1.4 tones including our own body weight!).
All research projects have rough days, and today was one of those. We learned around 10 am today – after much fiddling – that the RFID readers that Evan (Masters student) had painstakingly built over the past 4 months are not working properly. This is after having tested them all in the lab in Corvallis!
The RFID readers are pretty cool (in theory) because they will allow us to get a picture of where hummingbirds are across the landscape without us always having to be there. RFID tags are used by pet owners to keep track of their dogs and cats. Essentially, a very small chip is implanted under the first few layers of skin. When the chip gets near a reader the bird ‘checks in’ – tells us who it is, and when they visited. If we can get enough of these out across the tropical landscape, we will have the first picture of how far all of these species of hummingbirds travel each day to get nectar. We can also test conservation-types of questions such as which hummingbird species (if any) typically cross gaps in the jungle caused by agriculture.
At the moment, we are all optimistic that the problem with the RFIDs can be fixed, but the issue does stretch the mind a bit. It is highly unlikely they were ALL damaged in transit (none work). Our best guess is that because the relative humidity is so much higher in Costa Rica, this is playing havoc with the micro-computer, or the antennas…Hopefully I’ll have better news on this tomorrow. Time to go to bed as we’re up at 5:15 to continue a pollination experiment.