Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Urbanization favors sedentary males

02.05.2007
Urbanization changes landscapes and local environments, which can alter the life histories and traits of the creatures living in and around these areas.

Studying European blackbirds (Turdus merula), Jesko Partecke and Eberhard Gwinner (Max Planck Institute for Ornithology) discovered certain adaptive traits, that in the long run, could lead to more offspring. The study, "Increased sedentariness in European Blackbirds following urbanization: a consequence of local adaptation?," appears in the April issue of Ecology.

Earlier field studies revealed a greater tendency for birds to over-winter in urban populations of migratory species such as the European Blackbird and the European Robin, especially when compared with populations of the same species living in nearby forest and rural habitats.

"The decision to migrate is probably influenced by both genetics and environment," say the authors in the study. "In this study, we wanted to determine if changing migratory habits were due to changes in genetic composition in urban populations, or were environmental-induced."

To test the effects of environment and genetics on migration habits, the scientists set up an experiment where they raised birds from both the city and forest environments. They monitored their movements at night and during the day and measured body fat, an indicator that the bird is preparing for migration. The researchers also looked at sexual maturity, to see if migratory disposition had an impact on the seasonal timing of reproduction.

Partecke and Gwinner found that the birds exhibited migratory traits - fat buildup and more nocturnal activity, during periods in the spring and fall. While they found little difference between forest and urban females, urban males were less likely to show a desire to migrate (migratory disposition). Furthermore, those individuals with a lower migratory disposition were more likely to develop gonads earlier in the season than their forest counterparts with higher migratory propensity.

"We suggest the migratory drives for urban and forest blackbirds are genetically driven and consider it likely that they are the result of microevolutionary changes following urbanization," say the researchers.

So why the males and not the females? The authors suggest that selection in urban habitats operates differently on the migratory habits of male and female European blackbirds. In partially migratory species, sedentary individuals are not only able to establish territories and to begin pair formation earlier than migratory birds, but also may have a longer reproductive season. The earlier onset of favorable conditions for breeding in urban areas should, thus, favor selection for sedentariness. The advantage of both sedentariness and earlier onset of territory establishment in terms of reproductive success for males seems to outweigh that of the females.

Annie Drinkard | EurekAlert!
Further information:
http://www.esa.org

More articles from Ecology, The Environment and Conservation:

nachricht Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

nachricht 100 % Organic Farming in Bhutan – a Realistic Target?
15.06.2018 | Humboldt-Universität zu Berlin

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

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...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

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.

Im Focus: Sharp images with flexible fibers

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>