Navigation Links
Migrating birds sprint in spring, but take things easy in autumn
Date:9/2/2014

Passerine birds, also known as perching birds, that migrate by night tend to fly faster in spring than they do in autumn to reach their destinations. This seasonal difference in flight speed is especially noticeable among birds that only make short migratory flights, says researcher Cecilia Nilsson of Lund University in Sweden, in Springer's journal Behavioral Ecology and Sociobiology.

Nilsson, in a group led by professor Thomas Alerstam, used a tracking radar to measure over three years the speed by which birds flew over Falsterbo Peninsula, a bird migratory hot spot in south-western Sweden. The seasonal differences they found correspond with those recorded for other nocturnal passerine migrants at other sites in southern and northern Sweden.

The seasonal differences in airspeed are more noticeable among short distance migrant birds. Nilsson and colleagues suspect that such birds fly faster in spring because they have a greater urgency to reach their breeding grounds first and to choose the best territories, mates and other resources. While the time savings made in spring might seem miniscule, these remain important because they influence the arrival order of individual birds. In autumn, the birds take things more slowly because they are not as pressured to reach their winter grounds.

Wind is the one weather condition that influences birds' decisions the most about when to take off. In fact, Nilsson and co-authors discovered that passerine birds can actually fine-tune their flights to make full use of winds, making their flying and subsequent migration easier. Short distant migrants have higher ground speeds (speed relative to the ground below) than airspeeds (own speed relative to the air around the bird) in both seasons. Hence, these birds make use of wind assistance. In contrast, long distance migrants often travel with airspeeds exceeding ground speeds, resulting from flying in headwinds, in autumn. These findings correlate with previous studies done at the University of Lund which showed that long distance migrants receive very little wind assistance on average.

Nilsson and colleagues also found that short distance migrants have a more flexible flight schedule, because they are able to wait for good nights. Long distance migrants on the other hand must fly on more nights to reach their destination in good time, even if it means traveling during unfavourable wind conditions. While waiting for nights with good wind conditions will save them energy, it will prolong their migration.

"These results indicate surprisingly fine-tuned seasonal modulation of airspeed and responses to wind. Associated with different behavioural strategies, passerine birds thus are adapted to different levels of time selection pressures during spring and autumn migration," Nilsson summarizes.


'/>"/>
Contact: Laura Zimmermann
laura.zimmermann@springer.com
49-622-148-78414
Springer
Source:Eurekalert  

Related biology news :

1. Its a bird, not a plane: York U study finds migrating songbirds depart on time
2. Galapagos tortoises are a migrating species
3. Drought in the Horn of Africa delays migrating birds
4. Notre Dame research reveals migrating Great Lakes salmon carry contaminants upstream
5. Hundreds of insect scientists migrating to Rapid City this week
6. New study will help protect vulnerable birds from impacts of climate change
7. Not just for the birds: Man-made noise has ripple effects on plants, too
8. UCSB researchers find that less is more, for female cowbirds
9. Hitch-hiking with birds for life
10. Songbirds learning hub in brain offers insight into motor control
11. Scientists find that rain may not always be a welcome thing to waterbirds
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Migrating birds sprint in spring, but take things easy in autumn
(Date:6/1/2016)... , June 1, 2016 ... in Election Administration and Criminal Identification to Boost Global ... a recently released TechSci Research report, " Global Biometrics ... Region, Competition Forecast and Opportunities, 2011 - 2021", the ... billion by 2021, on account of growing security concerns ...
(Date:5/9/2016)... , UAE, May 9, 2016 ... it comes to expanding freedom for high net worth ... Even in today,s globally connected world, there is still ... system could ever duplicate sealing your deal with a ... second passports by taking advantage of citizenship via investment ...
(Date:4/26/2016)... , April 27, 2016 ... the  "Global Multi-modal Biometrics Market 2016-2020"  report to ... ) , The analysts forecast the ... CAGR of 15.49% during the period 2016-2020.  ... number of sectors such as the healthcare, BFSI, ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... 2016 /PRNewswire/ - BIOREM Inc. (TSX-V: BRM) ("Biorem" or "the ... major shareholders, Clean Technology Fund I, LP and Clean ... based venture capital funds which together hold approximately ... fully diluted, as converted basis), that they have entered ... equity holdings in Biorem to TUS Holdings Co. Ltd. ...
(Date:6/27/2016)... ... June 27, 2016 , ... Rolf ... join the faculty of the University of North Carolina Kenan-Flagler Business School ... and entrepreneurship at UNC Kenan-Flagler, with a focus on the school’s international efforts, ...
(Date:6/24/2016)... ... , ... While the majority of commercial spectrophotometers and fluorometers use the z-dimension ... are higher end machines that use the more unconventional z-dimension of 20mm. Z-dimension ... bottom of the cuvette holder. , FireflySci has developed several Agilent flow cell ...
(Date:6/23/2016)... , June 23, 2016 /PRNewswire/ - FACIT ... Ontario biotechnology company, Propellon Therapeutics ... development and commercialization of a portfolio of first-in-class ... Epigenetic targets such as WDR5 represent an exciting ... significantly in precision medicine for cancer patients. Substantial ...
Breaking Biology Technology: