By Kara Leimberger (PhD Student)

As mentioned in previous posts, one of our research questions involves temporarily removing Heliconia – a plant that provides nectar to many hummingbird species. Before and after removing Heliconia, we will measure which plants the hummingbirds visit and how often they are visiting. Will the hummingbirds miss the Heliconia so much that they leave the study area to search for nectar elsewhere? In this case, we might see less frequent visitation to the remaining flowers in the plot. On the other hand, maybe hummingbirds will stick around but consume more nectar from different plants, especially if the study plot is not connected to other easily accessible patches of forest.

For example, imagine that your typical breakfast consists of eggs, toast, and orange juice. Imagine that you wake up one day, hungry and ready for breakfast, but then realize that you are suddenly out of eggs! Do you then fill up on toast and orange juice? Do you find the stale corn flakes that have been sitting in the pantry for months? Or do you get out of your pajamas and make a trip to the grocery store (or if you’re a hummingbird, another forest patch)?

To measure how hummingbirds respond to Heliconia removal, we are using portable, camouflaged cameras positioned next to nectar-producing flowers. The cameras are programmed to take one picture every second, which means that a single camera running during the day (~12 hours) gives us 43,200 photos! The camera method lets us be very efficient (or lazy?) researchers because we do not have to watch flowers all day, but it sure means we have lots of photos to look at! We hope to use a computer program (MotionMeerkat) to sift through all these data quickly and accurately to find the moments when the flowers have visitors. When we tested cameras here at the research station, flower visitors have included hummingbirds, butterflies, wasps, and curious tourists. Below are some of the hummingbird photos we have gotten so far!

Green Hermit visiting Heliconia ramonensis

Green Hermit evaluating a H. tortuosa (and apparently our camera)

Rufous-tailed hummingbird visiting a domesticated banana plant (which has very abundant and sugary nectar)

This is one of the short-billed more generalized species that we study here in Costa Rica. Despite weighing in at <4 g, this bird can intimidate other hummingbirds nearly three times its size to defend a nectary clump of flowers.

Species of the day: Passiflora vitifolia (passion flower) found in one of our fragmented forest patches today. One of our research questions is how local extinction of Heliconia will indirectly influence other plant species like this one (via pollinator limitation). This is a favorite of hummingbirds because of its high amounts of sugary nectar… but can it keep hummingbirds coming to the patch even after Heliconia is gone?

By Matt Betts

2016 marks our 8th year at Las Cruces Biological Station in the pursuit of hummingbirds, pollination, life, the universe and everything (apologies to Douglas Adams). This year is a milestone as is the first full field season of our work on the importance of ‘hub’ species to pollination networks; over the years we’ve found that a remarkable number of hummingbird species (at least 9) use Heliconia tortuosa as a resource during the dry season. We now also know that tropical forest fragmentation is causing a decline in this plant species (evidence lies in much reduced densities of ‘baby’ heliconias in small forest patches). So what will be the ecological impact of these declines? What happens when you remove a critical ‘hub’ from a network? (e.g., a key ‘friend’ in a social network, a key individual in a terrorist network, a key neuron in the brain, or in our case…a keystone plant from a pollination network).

It turns out very little is known about the properties of pollination networks when species are removed. 

One possibility is that the network collapses; dependent birds depart from locations where heliconia no longer exist and as a result pollination of many other flower species suffers. An alternative is that “re-wiring” occurs; birds just change their foraging habits a bit (e.g., Big Macs versus steak) and keep up their pollination services to remaining plants. So, over the coming 3 years we intend to test these ideas using various experiments and methods that you’ll hear about in more detail as the months roll by.

I should mention that we’ve added several key members to our team: Prof Andy Jones (Oregon State Botany) is working with us on genetics and plant ecology. Kara Leimberger is visiting this season before starting her PhD in my lab in the fall. Jessica Greer (OSU graduate) has worked with us for three years as an integral part of our citizen science project and pollen identification effort but until now had not seen our study site (or the tropics for that matter). Finally, Luis Arias, a PhD student from University of Toronto under the supervision of Prof. Helene Wagner is here to work on H. tortuosa demography and seed dispersal.

Kara Leimberger, Jessica Greer and Luis Arias (left to right) – the new additions to the OSU Hummingbird Research Project.

Due to the hard work of our Costa Rican education coordinator – Carla – and the many Costa Rican school children who participated, the communication lines between budding Oregonian and Costa Rican scientists have been opened. School children in both countries are collecting data on hummingbird abundance, diversity and nectar use to find out whether landscape fragmentation alters hummingbird distribution patterns. These letters are to share data, tips, and just to find out more about each other.

As mentioned in previous posts, we are finding that pollination seems to be resulting in decline of Heliconia tortuosa – species that we think is critical for many hummingbird species (we’ve seen > 8 species visiting this flower). In our next experiment, we are going to see what happens to hummingbird movement if this flower goes locally extinct.

Here is a photo of a female green hermit at her nest. Notice the radio transmitter attached to her back (which Adam used to find the nest in the first place). We will use transmitters like this to track movements of birds once heliconia density has been reduced (by covering flowers temporarily). MGB

Species, well community, of the day: Tropical cloud forest! This is one of my favorite patches in our study “Patch 16” where yesterday we captured 12 violet sabrewings and we see howler monkeys and emerald toucanets. This is an example of a large, healthy patch of forest where both heliconia and hummingbirds are common. MGB

Species of the day: White-tipped sickle bill! This is one of my favorite species. It is quite specialized (its “sickle” bill allows it to get into very curved flowers). As a result, it needs to move a long way to find the food that it needs. One of our largest hummingbirds (~11 g), it is a bit like watching a fighter jet mixed with a muppet move through the jungle.

Teacher Research Experience Blogs

This year we are lucky to have three teachers from Oregon and our Oregon education coordinator Kari come down and help us with the research in Costa Rica. They are here as part of a National Science Foundation (NSF) program called “Research experiences for teachers” (RET). This is a similar program to what is funding Christina and Tyler. We are lucky to have such a great group that is keen to learn and full of new ideas. While the teachers are here they will have three main goals:

1. To learn participate directly in research – The teachers get to help us in the field and see the work we do up close. They get to see many new techniques and to be a part of the actually data collection. The saying goes that “seeing is believing”, but I would go further and say that seeing, touching, smelling and hearing the jungle in which we work is critical in order to truly appreciate this amazing ecosystem. The teachers will be able to share first-hand experience and accounts with their classes back home.

2. Design and implement their own project – The teachers are conducting their own experiment here in the garden to examine nectar removal rates by hummingbirds. We help the teachers by working with them on sampling designs and using our local knowledge.

3. Bring the research to the classroom – While here each of the teachers are blogging daily about their experiences and sharing with all of the classes back in Oregon. You can also follow their blogs here: http://drouhardincostarica.blogspot.com/, http://4thgradegeckos.blogspot.com/, http://garfieldgeckos.edublogs.org/

4. Linking science education efforts in Oregon and Costa Rica – The teachers are visiting classes here in Costa Rica and establishing connections that will enable students from both countries to share their experiences as they participate in the hummingbird projects. The teachers are working with Kari (OSU) and Carla (OTS) to build on each other’s experiences with science outreach.

Editors note (MGB): One of the major parts of the outreach part of our project is to encourage kids to be enthusiastic about biodiversity. We are working with kids in grades 3-5 in Costa Rica and Oregon who are learning about pollinators and collecting some data for us. We hope Ava’s adventures in the tropics – and with our project – will inspire other families to learn more about nature.

Ava Betts

There is one mammal I have not told you about: HOWLER MONKEYS*. It was everyone’s ambition to see at least one. When we went to Amistad (the biggest national park in Central America) everybody HEARD them, but did not SEE them (we saw the resplendent Quetzal though*) and everyone thought that was where we would see them too. It was a bit of a shame. We thought our only chance to see monkeys had gone. But surprisingly, that was not the last we heard, (or saw) of them.

I am on the ferry to the Osa Peninsula. The Osa Peninsula is a place where there are many tourists and lots of hotels, cabins to stay in, and seafood. We are on a closed in boat. It is a warm day but humid in the ferry. Once we all start moving, I thought, I can read. Indeed, I did read Wildwood. I read for a half an hour. When we got to the cabins we were staying in, we got settled and then stayed for a while. After that, we set off to a better beach for swimming. There were, apparently, rays in the water. Everybody still swam though*. The waves were huge! We did that for a while, but now let me tell you about the monkeys.

The Iguana Lodge is a good place to eat. You know, nachos, good sauces, seafood, nice desserts, etc. etc. Now we are having dinner, and something TOTALLY unexpected happened. MONKEYS. HOWLER MONKEYS!!! And there was one baby! That right there was the first time I have seen monkeys in the wild. It was a wonderful experience.

*Howler monkeys are medium sized monkeys that make sounds like a lion. I have a suspicion that the first people to explore Costa Rica thought this: What on Earth have I gotten myself into? There are lions???!!! This is how they sound:

Paste into your browser: http://www.naturesongs.com/howler2.wav

*See: My Encounter With a Resplendent Quetzal.

*We were not THAT scared!