Drs. Kristina Paxton and Patrick Hart were awarded a grant from the National Science Foundation (NSF) Grants for Rapid Response Research (RAPID) to assess the impact of Rapid ‘Ōhiʻa Death on Hawaiian forest birds. The project is entitled: “RAPID: Cascading effects of rapid and widespread mortality of a foundation tree species on animal communities in Hawaiʻi”
Rapid ‘Ōhiʻa Death or ROD, is a fungal pathogen causing rapid and widespread mortality of ‘Ōhiʻa (Metrosideros polymorpha), a foundation tree species in Hawaiian forests. ROD poses a serious threat to Hawaiʻi’s remaining native forests and the plants and animals that depend on ‘Ōhiʻa. Research focused on ROD to-date has been concentrated on understanding the pathology of the disease, how ROD is spread, and the impacts of ROD on ‘Ōhiʻa trees. However, there has not been an examination of how ROD is affecting animal communities reliant on ‘Ōhiʻa forests. ‘Ōhiʻa is an important nesting substrate and food resource for both insectivorous and nectarivorous Hawaiian forest birds, 57% of which are threatened or endangered, and there is no substitute for the volume, geographic spread, and year-round source of nectar provided by ‘Ōhiʻa. Given the foundational role of ‘Ōhiʻa in Hawaiian forest communities as the dominant tree in the canopy, the widespread or total loss of ‘Ōhiʻa would likely be catastrophic for endemic Hawaiian forest birds.
This project will use advances in recording technology to continuously record, over an extended period of time, the entire sound-producing animal community (i.e., biophony of a soundscape) within ‘Ōhiʻa forests across Hawaiʻi Island. By using soundscape analysis tools developed within the growing field of soundscape ecology the researchers will be able to rapidly assess changes in the biodiversity of audible birds, insects, and amphibian species associated with mortality of ʻŌhiʻa across the landscape. The research will also evaluate whether the diversity and composition of understory plant species moderates how reliant animal communities respond to the loss of a dominant forest tree species. The use of soundscape indices to model biodiversity following the loss of a foundation species represents a novel and relatively rapid method for assessing ecological change and would be applicable in a range of ecosystems outside Hawaiʻi.
The extraordinary findings of a genetic research team at the University of Hawai‘i at Hilo studying the ‘alalā (Hawaiian crow), one of the world’s most endangered bird species, are published in the current issue of the journal Genes. Biologist Jolene Sutton, an assistant professor at the University of Hawai‘i at Hilo who specializes in evolutionary genetics, led the team of UH Hilo colleagues Martin Helmkampf, a research scientist with the tropical conservation biology and environmental science program, and Renee Bellinger of the Conservation Genomics Research Group, along with collaborators from the Hawai‘i Endangered Bird Conservation Program, San Diego Zoo Global, and Pacific Biosciences, a Silicon Valley company that provides sophisticated genomic analysis systems.
The article, “A high-quality, long-read de novogenome assembly to aid conservation of Hawaii’s last remaining crow species,” describes the high-quality reference genome that was generated to assist recovery efforts for the ‘alalā.
“The quality of this assembly places it among the very best avian genomes assembled to date, comparable to intensively studied model systems,” according to a post on the UH Hilo Biology Department News website.
Researchers and conservationists are currently using this resource to better understand genetic diversity in the ‘alalā, and to develop tools that will help inform strategic pairings as part of the conservation-breeding program. This genome assembly is now publicly available.
The paper is the cover story of the August 2018 issue of Genes, a special issue on conservation genetics and genomics.
Led by Jolene Sutton, assistant professor at the University of Hawaii, Hilo, the team created an assembly which has provided critical insights into inbreeding and disease susceptibility. They found that the ‘alalā genome is substantially more homozygous compared with more outbred species, and created annotations for a subset of immunity genes that are likely to be important for conservation applications.
As reported in the latest issue of Genes — and featured on its cover — the quality of the assembly places it amongst the very best avian genomes assembled to date, comparable to intensively studied model systems.
“Such genome-level data offer unprecedented precision to examine the causes and genetic consequences of population declines, and to apply these results to conservation management,” the authors state. “Although pair selection and managed breeding using the pedigree has kept the inbreeding level of the ‘alalā population at a relatively low level over the past 20 years, the intensive and ongoing conservation management of the species requires a more detailed approach.”
UH Hilo conservation biologists use high-tech acoustics to study Rapid ʻŌhiʻa Death impact on forest animals
A fungal disease is ravaging native forests on Hawai‘i Island, killing huge swaths of ʻōhiʻa (Metrosideros polymorpha), the most abundant native tree in the state of Hawaiʻi. On Hawaiʻi Island, hundreds of thousands of ʻōhiʻa have already died from the fungus, Ceratocystis. Healthy trees die within a few days to a few weeks, hence the name Rapid ʻŌhiʻa Death or ROD. The disease has killed trees in all districts of Hawaiʻi Island and has the potential to kill ʻōhiʻa trees statewide.
So far, ROD research has concentrated on understanding the pathology of the disease, how it is spread, and the impacts of it on ‘ōhi‘a trees. But the decimation of the trees is destroying native forests as a whole, and in turn, posing a serious threat to the plants and animals that depend on healthy ecosystems created by ‘ōhi‘a trees.
This summer, UH Hilo biologists started a one-year study on the effects of ROD on animal communities in Hawaiʻi. The research is funded by a $197,000 grant from the National Science Foundation’s Grants for Rapid Response Research or RAPID program. The project is entitled “RAPID: Cascading effects of rapid and widespread mortality of a foundation tree species on animal communities in Hawai‘i.”
“[T]here has not been an examination of how ROD is affecting animal communities reliant on ‘ōhi‘a forests, which is an important nesting substrate and food resource for both insectivorous and nectarivorous Hawaiian forest birds, 57 percent of which are threatened or endangered,” explains lead scientist on the study Kristina Paxton, an adjunct assistant professor in the UH Hilo tropical conservation biology and environmental science program. “Given the foundational role of ‘ōhi‘a in Hawaiian forests as the dominant tree in the canopy, widespread or total loss of ‘ōhi‘a would likely be catastrophic for endemic Hawaiian forest birds.”
Acoustics: Recording the animal sounds of the forest as an indicator of biodiversity
Paxton is working on the study with colleague Patrick Hart, a UH Hilo professor of biology and a specialist in conservation of Hawaiian forests and forest birds. The team will be basing the research on high-tech recorded acoustics—bird song and other animal sounds of the forest—using technology out of the UH Hilo bioacoustics lab called the Listening Observatory for Hawaiian Ecosystems or LOHE, which was founded by Hart.
Paxton says the project will use advances in recording technology to continuously record over an extended period of time the entire sound-producing animal community within ‘ōhi‘a forests across Hawaiʻi Island.
Lab logo with bird and whale and the words: Listening Observatory for Hawaiian Ecosystems, LOHE Bioacoustics Lab, University of Hawaii at Hilo.“By using soundscape analysis tools developed within the growing field of soundscape ecology, we will be able to rapidly assess changes in the biodiversity of audible birds, insects, and amphibian species associated with the mortality of ōhi‘a across the landscape,” she says.
The research also will evaluate whether the diversity and composition of understory plant species moderates how reliant animal communities respond to the loss of a dominant forest tree species.
Paxton says the use of soundscape to assess ecological change could serve as a model in studying a range of ecosystems outside Hawaiʻi.
Drs. Jolene Sutton, Martin Helmkampf, and Renee Bellinger publish paper on the Hawaiian crow genome on the cover of Genes
Drs. Jolene Sutton, Martin Helmkampf, and Renee Bellinger of the Conservation Genomics Research Group, along with collaborators from the Hawaii Endangered Bird Conservation Program, San Diego Zoo Global, and PacBio publish in Genes. The article, “A high-quality, long-read de novogenome assembly to aid conservation of Hawaii’s last remaining crow species” describes the high-quality reference genome that was generated to assist recovery efforts for the ‘Alalā, one of the world’s most endangered bird species. The quality of this assembly places it amongst the very best avian genomes assembled to date, comparable to intensively studied model systems.
Researchers and conservationists are currently using this resource to better understand genetic diversity in the ‘Alalā, and to develop tools that will help inform strategic pairings as part of the conservation-breeding program. This genome assembly is now publicly available. This paper is the “Feature Article” of the August 2018 issue of Genes, and belongs to the special issue, “Conservation Genetics and Genomics.
Based on the recommendations of faculty, Kayuri Kadoya has won the Outstanding Graduating Senior Award for her excellence in academia and for her research at the College of Pharmacy. The Don Hemmes Award, which pays for one year of tuition, has been awarded to Kenton Wandasan who has also achieved high marks throughout his academic career. Congratulations to Kayuri and Kenton!
Image above: Kayuri Kadoya and Kenton Wandansan
Dr. Stan Nakanishi publishes Nature Protocols paper with an international team describing methods for sensory and motor experiments using decerebrate adult mice
Dr. Nakanishi and colleagues developed a collection of specialized techniques to record from live mice in order to study how the nervous system encodes sensory information, processes those signals, and produces movements in living organism, all without anesthetic complications. Briefly, this set of protocols describes the animal surgery techniques that can be used to study sensory-motor integration in live, adult mice whose brain is removed.
Using this preparation, we can better understand how sensory information is collected, integrated, how we produce complex reflex patterns. We can study cardiovascular and respiratory functions, and learn more about the spinal circuits that coordinate the muscle activity for movements and walking.
Dr. Jolene Sutton and colleagues make the front page of the Hawai’i Tribune-Herald for their mosquito research
“To protect Hawaiʻi’s unique, imperiled native birds, researchers from the University of Hawaiʻi at Mānoa and UH Hilo are teaming up with the Department of Land and Natural Resources (DLNR) and the U.S. Fish and Wildlife Service to adapt a ‘birth control’ method used across the U.S. mainland to control mosquitoes. The scientists are taking the first steps to adapt a safe, targeted and efficient mosquito control method known as Incompatible Insect Technique to reduce the population of the disease-carrying mosquitoes that harm native birds in Hawaiʻi.”
—A Department of Land and Natural Resources news release
UH Hilo Biology Graduate Ann Tanimoto and colleagues publish paper on the vocal repertoire of the Hawaiian crow
For most avian species, social behavior is critically important for survival and reproductive success. Many social behaviors in birds are culturally transmitted, and as bird populations decline across the globe, important elements of these behaviors may be lost. The Hawaiian crow or ʻalalā, Corvus hawaiiensis, is a socially complex avian species that is currently extinct in the wild.
As in other oscine passerines, vocalizations in the ʻalalā may be culturally transmitted. We compared the vocal repertoire of three of the last four wild ʻalalā pairs from the early 1990s to three current captive pairs at the Keauhou Bird Conservation Center in Volcano, Hawaiʻi to determine how acoustic behavior has been affected by changes in their social and physical environment.
Our results showed that measures of acoustic richness and diversity were similar between the aviary and wild population, however, there were some very notable changes in call rates as well as the types of calls being made. We found that the wild ʻalalā had a significantly higher call rate (calls per minute) than the ʻalalā in the aviaries. There were also repertoire differences which included the loss of alarm and the complete loss of broadcast/territorial calls in aviary ʻalalā. Our results show how socially learned behaviors may change over relatively short periods for an entire species. Understanding how the vocal repertoire and the functional context of vocalizations change may provide useful information for ongoing efforts to reintroduce the ʻalalā into the wild.
UH Hilo Stories: Climate Change Research at UH Hilo: Tree rings and Bird song (February 21, 2017)
American Association for the Advancement of Science (AAAS) Science Update (Podcast): Endangered Crow Calls (February 15, 2017)
Dr. Stan Nakanishi publishes PNAS paper on alphaB-crystallin protein and its unique properties of regenerating neurons
Nerves send signals throughout our brain, spinal cord, and body. Some nerves send sensory signals to the brain; other nerves send signals that tell our muscles to contract and produce movements. If nerves in the body are damaged, some of the nerves regrow but the recovery is usually incomplete, leading to problems with sensory or movement functions and even neuropathic pain.
The goal of this project was to learn more about a molecule that is important for the regrowth of damaged nerves. The molecule is called alphaB-crystallin (aBC), and this molecule helps nerves regrow after an injury. We found that aBC affects the recovery and regrowth of sensory and motor nerves, and that we can improve the recovery process by adding extra aBC after a nerve injury.
Professor Matt Knope and colleagues publish papers in the Journal of Fish Biology and in Paleontology
To asses the repeatability of an ecological study, Assistant Professor Matt Knope recently led a publication that both partially replicates and extends a previous study on the site fidelity (the likelihood of an animal to stay in one “home”) and homing ability of two abundant and ecologically important species of rocky intertidal sculpin fishes on the Oregon Coast. Knope and colleagues report in their new paper in the Journal of Fish Biology that by using a traditional mark and recapture technique in the field, that they find both species have high site fidelity and homing ability to individual tide pools confirming the findings of previous work. However, unlike in the previous study, they find that body size was not a good predictor of homing ability, but that sex was. In addition, their study extends the maximum homing distance of both species, but finds that homing success was negatively related to displacement distance from the “home” tide pools. These findings suggest that adult sculpin populations are likely to be highly sub-structured geographically, possibly contributing to the exceptionally high species richness of the group.
Read full article.
The effects of extinction events are not only caused by the intensity of the taxonomic losses (e.g., the number of species lost at a mass extinction event), but also by the selectivity of the extinction event (e.g., one group of animals being more susceptible to being lost at a mass extinction than another group). Assistant Professor Matt Knope recently co-authored a study in Biology Letters that proposes the use of logistic regression to quantify extinction selectivity, because the selectivity metric is independent of the extinction intensity and multiple predictor variables can be assessed simultaneously. The study uses this statistical technique to illustrate that the end-Permian mass extinction, the largest mass extinction in terms of taxonomic losses in the history of life (~252 million year ago), also had the largest influence on the physiological composition of the fauna. That is, marine animals that had little physiological buffering, or sophistication of their respiratory and circulatory systems (such as polychaete worms, sea cucumbers, and jellyfish), were statistically more likely to go extinct than animals with greater physiological buffering during the end-Permian mass extinction when ocean acidification and anoxia were thought to be widespread. This approach provides an avenue for quantifying the risk posed by the emerging biodiversity crisis that goes beyond simple projection of taxonomic losses.