Birds in Alberta oil fields forced to raise imposters at alarming rate

July 19, 2017, University of Manitoba
A savannah sparrow chick, a host species U of M researchers discovered, are being parasitized by the brown-headed cowbird at a high rate. Credit: Emily Pipher, U of M graduate student

Alberta's oil and gas infrastructure is providing a great living to the brown-headed cowbird, a bird species that tricks other songbirds into raising its young, a new University of Manitoba study finds.

Prairie songbirds, already struggling to cope with habitat fragmentation and degradation caused by agriculture and industrial development, are now facing the stress of this parasitic bird, which sneaks its eggs into host species' nests.

Nicola Koper, a professor in the Natural Resources Institute at the University of Manitoba, worked with her graduate students Jacy Bernath-Plaisted and Heather Nenninger on the study that was just published in Royal Society Open Science. They report that the presence of oil and gas infrastructure, such as wells, roads and power lines, has lead to a four-fold increase of brown-headed cowbirds in pastures with oil wells or natural gas compressor stations, probably because the birds use these as perch sites to seek out nests to parasitize.

"This increase in cowbird abundance led to dramatic increases in parasitism of nests," says Koper. "I was shocked at how large the impact was."

Brood parasitism has a variety of negative effects on a songbird nest: increased risk of abandonment by the parent, increased hatchling failure, songbird hatchlings being outcompeted for food by the bigger imposter, and higher predation rates, possibly because the newly hatched cowbirds are attractively loud.

Given that parasitized Savannah sparrow nests at her study sites suffered, Koper's paper warns that this increase in parasitism pressure might hurt regional populations of this species. But there are solutions.

Koper's paper suggests that industry can mitigate this by reducing perch sites the cowbirds use. For instance, could be buried, and future wells can be constructed in locations that minimize the need for new roads.

"Our society is going to be dependent on fossil fuels for many more decades," says Koper, "but we can use these resources in ways that reduce their impacts on the environment."

Explore further: Cowbird moms choosy when selecting foster parents for their young

More information: Jacy Bernath-Plaisted et al. Conventional oil and natural gas infrastructure increases brown-headed cowbird ( Molothrus ater ) relative abundance and parasitism in mixed-grass prairie, Royal Society Open Science (2017). DOI: 10.1098/rsos.170036

Related Stories

Study documents evidence of 'mafia' behavior in cowbirds

March 5, 2007

“The Sopranos” have some competition — brown-headed cowbirds. Cowbirds have long been known to lay eggs in the nests of other birds, which then raise the cowbirds’ young as their own. Sneaky, perhaps, but not Scarface.

'Alien' eggs benefit mockingbirds

December 7, 2011

( -- Mockingbirds rarely remove the ‘alien’ eggs parasitic cowbirds lay in their nests because keeping them dilutes the risk of their own eggs being attacked.

Recommended for you

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...

The taming of the light screw

March 22, 2019

DESY and MPSD scientists have created high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might ...

Male fish can thank genes for colourful looks

March 22, 2019

Striking traits seen only in males of some species – such as colourful peacock feathers or butterfly wings – are partly explained by gene behaviour, research suggests.

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.