No early birds getting the worms: Songbirds risk missing peak food supply
June 3, 2013 — A mismatch between the departure schedules of songbirds and higher spring temperatures at their breeding sites is putting them at risk, according to a new study out of York University.
The study, "A Trans-Hemispheric Migratory Songbird Does Not Advance Spring Schedules or Increase Migration Rate in Response to Record-Setting Temperatures at Breeding Sites," published in the journal PLOS ONE, tracked the spring migration of purple martins over five years from the Amazon basin to two breeding sites in eastern North America. Researchers outfitted the birds with tiny geolocator "backpacks" to record data on their movements and found that the birds' departure times between years were surprisingly consistent, despite variation in temperature at their final destination.
"We found that purple martins migrating between the Amazon Basin and North America did not adjust their migration timing even during the hottest spring on record in 2012," says study author Kevin Fraser, a Postdoctoral Fellow in York's Department of Biology, Faculty of Science. "This means that they arrived 'late' for the advanced spring, and likely missed out on peak food they need to be productive breeders."
Aerial insectivores, like purple martins and other swallows, are experiencing strong population declines, particularly species migrating longer distances and populations breeding further north. Scientists have shown in a European species that declines may be due to an inability to advance arrival schedules to match a warming climate. This study provides the first direct evidence of a discrepancy between higher spring temperatures at breeding sites and departure schedules of individual songbirds.
"Our results suggest that long-distance migrants may receive limited or conflicting environmental cues about conditions at the breeding grounds while still at overwintering sites or along migration routes," says Fraser. "Once en route, the birds received no temperature cues of the warm spring until they reached the US Gulf coast, at which point it was likely too late to get to breeding sites earlier." Fraser says such mistiming is an active area of new research, and with climate change may be an important contributing factor to migratory songbird declines.
"Some migratory songbirds may not have the flexibility they need to respond quickly to earlier springs and more variable weather with climate change, which could contribute to the strong population declines we see in many species. Identifying which species or populations may be at greatest risk will be very important for guiding effective conservation action."
He says the study suggests that migration timing and rate in purple martin is not highly sensitive to short-term variation in temperature and rainfall, and that multiple years of increasing spring temperatures may be required to shift the birds to an earlier breeding arrival time through natural selection for earlier departure from tropical overwintering sites.
Welcome to SUV System Ltd!
SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.
We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.
SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com
Electronic Components distributor:http://www.suvsystem.com
Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html
IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html
LED Distributor:http://www.suvsystem.com/l/LED-1.html
Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html
Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html
Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html
Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html
SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc
we are focus on the following fields,and hope we can help you.
CRCW080520R0JNEA CRCW080520R0FKTA CRCW080520R0FKEB CRCW080520R0FKEAHP CRCW080520R0FKEA CRCW080520K5FKTA CRCW080520K5FKEA CRCW080520K0JNTA CRCW080520K0JNEB CRCW080520K0JNEA CRCW080520K0FKTC CRCW080520K0FKTA CRCW080520K0FKEB CRCW080520K0FKEAHP CRCW080520K0FKEA CRCW0805205RFKTA CRCW0805205RFKEA CRCW0805205KFKTA CRCW0805205KFKEA CRCW0805200RKNEAIF CRCW0805200RJNTA CRCW0805200RJNEB CRCW0805200RJNEA CRCW0805200RFKTA CRCW0805200RFKEB CRCW0805200RFKEA CRCW080522K1FKEB CRCW080522K1FKEA CRCW080522K0JNTA CRCW080522K0JNEB CRCW080522K0JNEAIF CRCW080522K0JNEAHP CRCW080522K0JNEA CRCW080522K0FKTA CRCW080522K0FKEB CRCW080522K0FKEA CRCW0805226RFKTA CRCW0805226RFKEA CRCW0805226KFKTA CRCW0805226KFKEA
http://www.suvsystem.com/a/2071.aspx
