"Our long-term study shows that El Niño, a global climate pattern, drives Sulfur butterfly migrations," said Robert Srygley, former Smithsonian post doctoral fellow who is now a research ecologist at the US Agricultural Research Service, the chief scientific research agency of the U.S. Department of Agriculture.
Climate change has been linked to changes in the migration of butterflies in North America and Europe but this is one of the first long-term studies of environmental factors driving long-distance migration of tropical butterflies.
For 16 years, Srygley and colleagues tracked the progress of lemony yellow Sulfur butterflies, Aphrissa statira, a species found from Mexico to Brazil, as they migrate across central Panama from Atlantic coastal rainforests to the drier forests of the Pacific coast.
"The El Niño Southern Oscillation—a global climate cycle—turns out to be the primary cause for increases in the plants that the larvae of these butterflies eat. El Niño results in dry, sunny days in Panama, which favor plant growth. When the plants prosper, we see a big jump in the number of Statira Sulfur butterflies."
Peak Sulfur butterfly migrations take place a month after the rainy season begins in Panama. Because butterfly development—from egg to larva to pupa to adult—takes about 22 days in the laboratory, Srygley thinks that these butterflies lay their eggs on new leaves produced by vines only four or five days after the rains begin. His team tracked the production of new leaves by two of the butterflies' host plants for 8 years. Drier years resulted in more new leaves.
The number of migratory butterflies was greatest in El Niño years, with one exception. The El Niño Southern Oscillation is a global-scale climate phenomenon characterized by changes in sea surface temperatures. In Panama, El Niño years have less rainfall during the dry season and higher plant productivity, with the one exception being an unusually wet El Niño year.
El Niño is global in its impact. In deserts and tropical seasonally-dry forests world-wide, a warm tropical Pacific Ocean surface is associated with increased rainfall resulting in seed germination and plant growth. The effects of increased primary productivity cascade upward into higher trophic levels resulting in periodic outbreaks of herbivorous species and migratory activity.
Neotropical wet forests are different because El Niño years are drier, but moderate drought results in increased primary productivity similar to that in desert and tropical dry forests. Thus the lowland forests of Panama fall into a set of habitats encircling the globe in which insect migrations are larger during El Niño years. However the Panamanian wet forest is in a class of forests that have the greatest abundance and diversity of herbivorous insects in the world, "It is like we had seen the tip of the iceberg and suddenly we realize its true size", Srygley suggested. The authors predict widespread insect migrations during El Nino years.
According to Srygley, "Understanding how global climate cycles and local weather influence tropical insect migrations should ultimately improve our ability to predict insect movements and effects such as crop damage."
This research is presented in the journal Global Change Biology and was conducted with support from the Smithsonian Institution and the National Geographic Society Committee for Research and Exploration. Research permits were provided by Panama's National Environmental Authority, ANAM, and meteorological data by the Panama Canal Authority, ACP, and the Terrrestrial-Environmental Science Program of the Smithsonian Tropical Research Institute.
STRI, headquartered in Panama City, Panama, is a unit of the Smithsonian Institution. The institute furthers the understanding of tropical nature and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems.
Further reports about: > Agricultural Research > El Niño > Pacific Ocean > Pacific coral > Plant Growth > Smithsonian > Tropical Research > butterfly migration > butterfly migrations > global climate cycle > global climate cycles > herbivorous insects > sea surface temperature > seed germination > tropical diseases > tropical dry forests > tropical insect migrations
Kidney tumor: Genetic trigger discovered
19.06.2018 | Julius-Maximilians-Universität Würzburg
New type of photosynthesis discovered
18.06.2018 | Imperial College London
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
19.06.2018 | Life Sciences
18.06.2018 | Earth Sciences
18.06.2018 | Process Engineering