Research:
Jonathan Slifkin was here for 3 months continuing the work of Izzy Soane and Jeffrey Roth on studying Mixed Species Feeding Flocks (MSF) in the reserve. Mixed species feeding flocks are just that, flocks of birds of at least 2 different species moving and feeding together. While they are found around the world, they are particularly prevalent in the Neotropics. They are thought to provide antipredator benefits and/or facilitate foraging efficiency and can be negatively impacted by deforestation so can be seen as an indicator of forest health.
Jonathan observed 31 different flocks ranging in size from 3 birds to 24 birds, and composed of between 2 species to 12 species. Out of 108 bird species observed during his surveys, 32 species were seen to participate in MSFs. Jonathan found that Common Chlorospingus were the most abundant bird species in MSFs by far, followed by Red-headed Barbet, Silver-throated Tanager, and Slate-throated Redstart. Jonathan also calculated the flocking propensity (likelyhood that a bird species will join a MSF) by comparing the total number of species seen during surveys with number of that species seen in a MSF. While Common Chlorospingus was the most abundant species, Red-headed Barbet and Black-cheeked Warbler had higher flocking propensities at 42% and 41%, while Common Chlorospingus was only at 30%. Barred Becard had the highest flocking propensity at 75%, but as only a few were observed, this number may not be accurate.
He also found that he observed a number of MSFs of larger size later in the day after the surveys were complete. As such he suggested altering the survey protocol to include surveys at different times of the day to see if more or larger flocks occur later in the day.
Images: Common Chlorospingus, Slate-throated Redstart, Species found in MSFs, Flocking Propensity, and Barred Becard.
| Species | Number of observations outside mixed flocks | Number of observations in mixed flocks | Flocking propensity. |
| Common Chlorospingus | 118 | 50 | 29.76% |
| Red-headed Barbet | 18 | 13 | 41.94% |
| Silver- throated Tanager | 41 | 13 | 24.07% |
| Slate-throated Redstart | 71 | 13 | 15.48% |
| Black-cheeked Warbler | 13 | 9 | 40.91% |
| Barred Becard | 2 | 6 | 75.00% |
Harry Elliott and Charlotte Smith from the United Kingdom have been at the reserve since April studying the diets of hummingbirds in the cloud forest. They observed 13 different hummingbird species feeding on 13 different plant species, as well as observing 3 different instances of hummingbirds eating insects. For understory species, heliconia species were the most commonly fed upon by hummingbirds and was used by several different species. For canopy species, there was a wider variety of plants used, but the most commonly used was Gonzalagunia rosea and Saurauia montana.
While they were conducting their study they made a discovery! They observed a number of the hummingbirds feeding directly from the fruits of the tree. After some investigation, they found that this behaviour had only been mentioned very briefly a couple of times before in the literature and usually only in passing. As this was a very rare behaviour, they chose to look into in more depth and focused on observing the feeding at the S. montana trees. Locally called the ‘Snot Tree’, S. montana produce fruits that are very sweet and full of a sticky syrup (see photo). This allows the hummingbirds to suck up the syrup when they pierce the fruits. As the fruits were very popular with a number of the animals in the forest, ripe fruits were only available for a few weeks, after which they hummingbirds no longer visited the fruits, so Harry and Charlotte were very lucky to observe this behaviour when they did. They have submitted their observations of this unique behaviour to a journal for publication and we look forward to seeing their work in print!
Agroforestry Project:
Three students from Borderless World Volunteers and McGill University in Canada were with us over the last few months doing a project on agroforestry. Agroforestry is the practice of growing trees alongside crops and within pastures. This provides a lot of benefits for the environment (increased biodiversity, erosion control, better soil quality), livestock and crops (provides shade and fodder, improves crop yields), and farmers (enhanced income in the form of cash crops from the trees).
Before arriving, Cordelia, Megan, and Dasha raised funds to purchase and plant trees in local farmers fields. Upon arrival, they met with a number of people to learn about agroforestry and the best trees to plant in the area, and source trees to purchase, and went to local farmers markets to make contact with farmers and create some interest in the project. They ended up planting trees in the fields of our local workers (Edgar and Oscar), our neighbouring dairy farmer (Marcos), and the owner of Quesos Canaan (Willberth). With the aid of our volunteers and some local workers they hired to help, they spent a few intensive weeks prepping the land and planting a variety of fruit and forage trees in sugar cane and coffee plantations, as well as a dairy pasture. Quite a success!
The agroforestry project at Cloudbridge consisted of three volunteers – Megan, Cordelia, and Dasha – working on local farmers’ plots to improve their sustainability. Agroforestry is essentially the idea of creating food forests; a variety of tree species are grown alongside croplands or pastures. Our project grows from a deep appreciation for how forests provide lifelong support for communities, and we learned much from a community interested in improving its sustainability. The five-week-long project culminated in the planting of over 500 trees of 30 different species among the plots of four community members.
My name is Dasha, and I was an agroforestry project volunteer at Cloudbridge. I am majoring in Earth Systems science at McGill University. In my hometown of Saratoga, California, I’ve spent a lot of time volunteering for environmental and educational causes: tree planting organizations, nature camps for children, tutoring, a donkey sanctuary, an ocean cleanup organization. My most valued time is time spent away in nature, and I am highly passionate about any and every opportunity to give back to the planet! Working in the San Gerardo community on the agroforestry project was an incredibly exciting experience given the community’s openness to sustainability initiatives and our opportunity to plant so many food-providing trees!
My name is Megan, and I’m one of three girls that worked on an agroforestry project as a volunteer while living at Cloudbridge Nature Reserve. I’m currently studying cognitive and neurosciences at McGill University, with my hometown being Cooperstown, New York where I am an active volunteer in the medical and environmental communities. My house is set on a 30 acre apple orchard where I got my first taste of planting and caring for trees, and I jumped at the opportunity to help plant more diverse food forest systems with local farmers who will cherish them. I am passionate about causes such as this that not only give to people but also to the world around us, and I can’t wait to watch the success and developments of our project in future years!
Hi! I’m Cordelia Dingle and I ran the documentation and media for our agroforestry project with Cloudbridge Nature Reserve and Borderless World Volunteers along with Megan and Dasha, I am a student at McGill University. I am majoring in Geography: Urban Systems with a minor in computer science and environmental studies. Originally American, I grew up and went to school in both Montreal and Toronto. I’ve been a part of my school’s robotics team and blockchain hackathon, and well as leading Model UN and being a provincial level archer. was originally interested in planning and being part of this project because of my interest in learning how to run, execute and document/share sustainability initiatives. I can definitively say that working directly in a community was one of the most rewarding experiences of my life.
Hi, my name is Amanda and I’m originally from Vancouver, Canada but currently studying Conservation Biology in the UK. I came to Cloudbridge as a research assistant and am currently assisting on multiple surveys, mainly Sulphur-winged Parrakeets, bats and owls.
My name is Gloria Greenstein. I came to Cloudbridge in pursuit of my growing interest in field biology and conservation biology. The past year I have been focused on marine ecosystems and wished to use the opportunity to expand my horizons. Here I am able to gain experience assisting researchers on site in a variety of projects including: camera trapping, species surveilance, animal behavior, restoration monitoring, and developing my own hypothesis.
Mike Pawlik from Poland was here for 3 months working on bird studies. His final month with us he undertook a small study to see if using non-native fruit feeders would attract additional birds to an area. His initial idea was that by providing a mixture of non-native and native fruits, these feeders could be used to enhance reforestation efforts as birds could help spread fruit tree and shrub seeds within the forest. He chose a study site that was known as a good bird site and set up a simple fruit feeder in an open area, and a second feeder in a more closed area. The feeders were baited with pineapple and banana the first week, a mixture of pineapple and banana and native fruits the second week, and only native fruits the 3rd week.. After a few days with no observations of birds using the feeders, he also installed a camera trap so he could monitor the feeder while he wasn’t present.
Unfortunately, science doesn’t always work the way you expect it to and over his 3 weeks of observations at the feeders, not a single bird came to feed on the fruit. The reasons for this were not entirely clear, but may have been due to a number of different factors including: feeder placement, feeder style, site choice, not enough time for the birds to habituate to the presence of the fruit, native fruit choice, and mammals stealing the fruits. White-nosed Coatis were particularly adept at stealing the fruits. Mike brain-stormed a number of reasons for the difficulties he had with the study and came up with a list of changes that could be made to improve the study and hopefully have some success in the future.
It just goes to show that science isn’t always about everything working perfectly the first time, and as much can be learned from failure as from success. Good for you for persevering Mike!
Callum Winter was with us for 3 months studying the presence of leaf cutter ants and their nests along our trails. While he found a number of leaf cutter trails, single ants, and small groups, he also found a total of 5 nests near the trails. The nests were made out of a variety of materials including bark pieces, leaves, and sand and soil. He also found a large tree with nests of different materials built on different sides of the same tree.
Photos: Map nest locations; 3 examples of leaf cutter ant nests
Hi my name’s Savannah and I’m a research assistant here at Cloudbridge! I’ll be working on several projects with researchers as well as my own project studying owls and bats at the reserve with a few other assistants. So far I’ve gotten to work with butterflies, sulfur wing parakeets and a bit of camera trap exploring!
Ellie Townsend was here for 3 months studying butterfly diversity to look at the effect of different habitats on butterfly presence and the impact of using different baits on the results. She set baited live traps in three different habitat types every week (planted, naturally regenerating, and old growth forest), rotating through the trails in the southern part of the reserve. Four different baits (banana, pineapple, dog dung, and fish sauce) were used during this study instead of just the fermented banana bait used previously. This was done to try to attract different species of butterflies to the bait traps instead of just fruit feeding butterflies.
Looking at the effectiveness of the baits, she found that they did not attract a significantly different number of butterflies, nor a significantly different number of species, to the traps. This is good news as it means each bait type is performing well. Looking at the community composition captured by the different baits, there was a difference in the species of butterflies attracted by the fruit baits (banana and pineapple), compared to the types of butterflies attracted by the stink baits (dog dung and fish sauce). This is also good as it means that the different baits are attracting different species, helping to diversify the butterflies caught in the study.
Comparing the different habitat types, she found that there was no significant difference in the number of butterflies nor species richness caught in the different habitats. Comparing community composition, she found that the natural regeneration and old growth habitats were most similar, although the planted habitat wasn’t too different from either of those. As the difference isn’t great, these results show there isn’t a dramatic difference between the three habitats in terms of providing butterfly habitat. This is good news in terms of our reforestation efforts and the overall health of the forest.
It will be interesting to continue this study with the new baits at different times throughout the year to see if these results change in the different seasons.
Graphs: Community composition comparison of fruit vs stink baits, community composition comparison of habitat typesPhotos: 3 different butterflies (sorry, don’t have the names)
Greetings, my name is Eric Livasy, from the United States. I am a Tropical Bird Intern participating in the Mixed Species Foraging Flock Study. It is a dream come true to research the rich diversity of species in Costa Rica!
