Tracking BFREE’s Migratory Songbirds

Connecting Northeastern Forest and Tropical Rainforest

MapforBFREE_2013BFREE is home to over 300 bird species; many of these make their summer homes in the USA and Canada. These migratory birds journey thousands of miles, twice annually, between their summer homes in the north (where they buildnests and raise young) and their winter homes at BFREE in the jungle. Amazingly, many of these birds weigh only a few grams – the weight of a dime! Yet they undertake amazing migrations every spring and fall. Scientists have been studying migratory songbirds at their breeding sites and at their wintering sites, but up until very recently we have been unable to directly track the migrations of small birds. We could see them at major ‘stopover’ sites along their migrations, but we had no idea where each individual was going or where they were coming from. This all changed with the miniaturization of a device called a ‘geolocator’. This tiny unit, weighing less than 1g, passively records the locations of small birds each day, allowing scientists to document, for the first time, the migratory behavior of songbirds.


At BFREE, we are studying the ecology and migrations of one of these amazing migratory songbirds, the Wood Thrush. We are catching Wood Thrushes in the jungle around BFREE and giving them small ‘backpacks’ – geolocators – that will record their migration north and back again. The backpacks are very small, and do not affect the birds’ survival. The downside of these small backpacks is that they do not transmit information. We have to recapture the birds in the following year when they return to BFREE in orderto download the migration and breeding site information from the geolocator. However, this is not as impossible as it sounds! Wood Thrushes, like many migratory songbirds, are site-faithful in winter, which means they return to the same patch of jungle each winter. So far we have retrieved 28 geolocator backpacks from Wood Thrushes at BFREE! This gives us amazing insight into their migrations and breeding sites.

For example, we have found out so far that the BFREE Wood Thrushes head to the USA in the summer – breeding in Pennsylvania, Kentucky, Tennessee, Georgia, South Carolina, Indiana, Virginia, and Maryland. These birds can probably be found in mature deciduous forests in these states in the summertime. We have also documented that all the BFREE Wood Thrushes fly directly across the Gulf of Mexico during their spring migration. This is a direct flight of around 600 miles that the birds accomplish in one day!


This is the first time migratory birds have been directly tracked between Belize and their North American breeding grounds. Why is this important? According to Breeding Bird Surveys in the US and Canada, populations of migratory birds are declining at an alarming rate. Wood Thrushes in particular have recently been added to the endangered species list in Canada. Their populations have declined by 60% in the last 40 years, across North America. Why are Wood Thrushes, and many other migratory species, disappearing? Scientists trying to figure out the answer to this question struggled because once birds left their breeding or wintering sites, they didn’t know exactly where they went. What areas are important migratory routes for specific breeding populations? Is there a structure linking specific breeding and wintering areas? More specifically, how flexible are migratory birds in their migration timing? Are they getting out-of-sync with their insect food in the north as climate change drives warmer spring in North America? These are all questions that we can now answer with information from tracking Wood Thrushes with geolocators. This year we have deployed over 80 geolocators on Wood Thrushes and we hope that many of these birds will come back to BFREE next winter and help provide information critical to conservation of their species.

Creature Feature: Bio-Luminescing Fungus


On one of his nightly walks through the jungle, BFREE Resident Biologist Dan Dourson stumbled upon what is now known to be quite a rare sight, the fruiting bodies (mushroom) of a bio-luminescing fungus species! The unlikely light source emanated from mushrooms growing out of a rotting cohune wood and aged seeds in BFREE’s organic cacao plantation.

Fungi, an interesting group of key organisms, facilitate decay of dead plant material, returning important nutrients to the ecosystem. The main body of any fungi, the mycelium (the bulk of the organism) is actually found living underground while the fruiting body or “mushroom” is the part most commonly seen and can be compared to the orange of a tree. While it is not uncommon for the mycelium to glow, it is exceptionally uncommon for mushrooms! Worldwide there are only 71 species known to possess this unique ability and one of them is right here at BFREE!

The mystery mushroom was identified to genus as a species of Mycena after sending images to a leading expert in bioluminescent mushrooms, Dr. Dennis Dejardin of San Francisco State University. These Mycena dubbed “Fairy-stools” emit a blue-green light that is an amazing experience to behold. At this very moment, dried specimens of this mushroom are enroute to Dr. Desjardin for further examination. Wouldn’t it be great if it turns out to be new to science?

The phenomenon of bioluminescence is natural light created by living organisms occurring in approximately 25 different phyla, many of which are entirely unrelated. Arthropods, certain crustaceans, several species of mollusks including the land snail Quantula striata from Malaysia, deep sea fish, marine microorganisms known as dinoflagellates, fungi and several varieties of slime molds all are known to possess this aerie quality. The most familiar animals in Belize possessing this unique power are the fireflies and headlight beetles whose light organs located on the abdomen and thorax regions of these insects are used to communicate and attract potential mates and in some cases, lure in prey to eat.


Several hypotheses of bioluminescence function in fungi include attracting hungry invertebrates which may aid in spore dispersal or used in attracting predators of mycetophagous invertebrates (organisms that eat mycelium). Some scientists speculate that glowing fungi are nothing more than by-products of some other metabolic process. In high elevation montane forests of the Maya Mountains, the jungle floor glows at night, a result of bioluminescent mycelium growing in decaying oak leaves and other decomposing vegetation.

Biological lighting differs from other light sources such as light bulbs and candlelight in being cool, producing little or no heat during illumination. Bioluminescent light is the result of a biochemical reaction during which two types of chemicals, luciferin and luciferase are combined together. The luciferase acts as an enzyme, allowing the luciferin to release energy as it is oxidized producing the light. There is ongoing research involving bioluminescence in the areas of evolution, ecology, histology, physiology, biochemistry, and biomedical applications.

So if you are wandering the jungles at BFREE at night (especially in the rainy season), take the time to turn off your headlamp and look around….you never know what might be glowing!

Birdathon Belize

birdathon belize bird raptor research institute

“Birds of Belize” author, H. Lee Jones, and a team of experienced birders spent the early morning hours on March 24 at BFREE as part of Birdathon Belize – a competition and fundraiser for the Belize Raptor Research Institute (BRRI). Lee was joined by Victor Bonilla, Emanuel Chan and previous BFREE employee and expert birder, Wilfred Mutrie, to create a strong team of four. The team’s goal was to identify 203 birds in a 24 hour period which would surpass the Belize record of 202 in one day. For every bird counted, a certain amount of money is donated to BRRI. The rules are strict; everyone in the group has to see and/or hear 95% of the birds in order to add the bird to the count for that day, so teams have to stay together and remain quiet. The team started at 4:00am and by breakfast at 7:30am had reached 98 birds, 2 birds shy of their target while at BFREE.

After breakfast they stopped at the river and within 15 minutes had added 10 more birds to their count! The remainder of their day was strategically planned to ensure they put themselves in areas to identify specific birds within their allotted time. They were to stop in the Savannah between BFREE and the Southern Highway, then on to Aqua Mar Shrimp Farm to locate various shore birds, with a stop immediately following in Punta Gorda where they were sure to see Laughing Gulls and a particular heron roosting in the mangroves. The day would end at the Southern Highway junction known as “The Dump,” in order to bird in a wet area, overgrown with reeds where they were sure to catch sight of a variety of species at dusk. We look forward to hearing if they break the record and are excited that the majority of the birds were spotted right here at BFREE!

New Cabanas

Mick Baisley and kai Reed finish the concrete for one of the new cabanas at BFREE.

Kai Reed and Mick Baisley finish the cement for one of the new cabanas at BFREE.

Recently BFREE has started a new projects: building three cabanas for researchers and visitors. There will be two 14 x 14 buildings and one 12 x 14 building. Everything will be handmade by Marcelino with help from Miguel, Mick, Elmer, Kai, Wilder and Rebecca. Currently they are busy mixing and pouring cement for the base and bending and cutting rebar for support. Marcelino hopes to be finished with the project by June.

New Species of Plant Named for BFREE Co-Founders, the Marlins

sedgeThe Marlins have a new plant species named in their honor! In the current issue of Kew Bulletin, co-authors (Wesley Knapp and Wayt Thomas) and I pay tribute to the Marlins and their accomplishments by naming Rhynchospora marliniana. We felt it especially appropriate to honor the Marlins and their contributions by naming a species that is widespread and common in Belize.

We are pleased to name Rhynchospora marliniana in honor of Jacob, Kelly, Sofia, Shaman, and Hyla Marlin. The Marlins are leading advocates for the conservation of biological diversity in Belize. Their founding of the Belize Foundation for Research and Environmental Education (BFREE), and their development of what is now an active and important biological field station are especially notable among their many achievements.

Adding prestige to the Marlins’ recognition is the place of publication of Rhynchospora marliniana. Kew Bulletin is the flagship scientific journal of the Royal Botanic Gardens, Kew, England, and one of the leading international journals of systematic botany in the world.

The beaksedges (Rhynchospora) comprise the largest genus of flowering plants in Belize. At least 46 species of these grass-like plants inhabit the country. Beaksedges occur in a variety of habitats, but are most diverse in savannas. Up to 16 species co-occur within a single savanna, and different savannas have different sets of species. As well, beaksedges often dominate these savannas. Floristically and ecologically, Rhynchospora is a very important genus.

On my first trip to Belize, Jacob Marlin introduced me to Belizean savannas. He showed me the savanna in the Deep River Forest Reserve, a short distance south of the BFREE border. There, I would make my first collection of what was to become Rhynchospora marliniana. However, I didn’t realize its status as a new species at that time. That recognition happened a couple months later, on a trip to the Mountain Pine Ridge in western Belize. There, in a savanna remnant, I found growing side-by-side Rhynchospora marliniana and R. plumosa, the species with which it had been confused. Quickly, I realized that two beaksedges were present. Their co-occurrence while maintaining their distinctions was compelling evidence of the existence of two species instead of one, one of them being new to science.Rhychmarliniana_drawing

In the time since my discovery on Mountain Pine Ridge, my co-authors and I conducted the thorough research on Marlins’ Beaksedge to document its status as a new species, its geographic distribution, and its ecology. During the course of additional trips, I found several more populations of it. On every one of these trips, Jacob, Kelly, and their children helped me with my research on Marlins’ Beaksedge, unknowingly. I say “unknowingly,” because I kept the naming a surprise until after publication.

Now, the Marlins have a species that bears their name. Marlins’ Beaksedge fittingly pays tribute to BFREE and many other accomplishments in Belizean conservation. More importantly, it serves as a reminder of the power of the few individuals who made these accomplishments possible through their vision, dedication, and perseverance.

Wood Thrush Research Using Geolocators

A Woodthrush with a new geolocator.

A wood thrush with a new geolocator.

This year at BFREE we have two researching groups that are here to study a bird called the wood thrush. This bird is a declining threatened species that lives in the US and Canada, but during the winter months, it migrates down to Belize and other Central American countries for warmer weather. Emily McKinnon and Kevin Fraser are the members of one such research group. Emily is completing her final year of banding birds here. For the past 3 years, she has come to BFREE and has been putting geolocators onto the birds. These devices use light sensors and a calendar to determine the latitude and longitude of the bird. Described as little bird backpack, the device is almost invisible underneath the birds plumage. After getting a geolocator, the wood thrush are then released and they complete their migration back North with their backpacks recording their migration pattern from and back to BFREE. When the birds arrive back at BFREE, so do Kevin and Emily. They come back and catch the birds once more, trying to recollect the locators and the information stored on them. Some years the return rate has been very low and they only get one or two out of the forty locators they put out the previous year, but other years, like this one, they get back over 10 locators along with some from previous years with multiple migrations worth of information on them. Emily’s research will be using data from the geolocators to discuss the migratory patterns of these birds and their likelihood of returning to the same breeding ground year after year. Some birds captured multiple years after the geolocators were place on them have data showing the bird returning to the exact same place in North America. Even at BFREE, some of the birds are caught in the same net they were caught in previously. Through Emily and Kevin’s research, we are learning about patterns in bird that have never been explored in depth before.