citizen scientists

Even The Common House Sparrow Is Declining | Earth Wise

March 17, 2021 By EarthWise Leave a Comment

According to the first-ever comprehensive assessment of net bird populations published in 2019, nearly three billion birds have disappeared in the United States and Canada since 1970. The study, by researchers from the Cornell University Lab of Ornithology, found that North American bird populations have lost 2.9 billion breeding adults during that timespan. Forests lost one billion birds, and grassland birds declined 53%.

According to a newer study from Cornell University, it appears that even the common house sparrow is declining. In parts of its native range in Europe, house sparrow numbers are down nearly 60%. Researchers from the Cornell Lab of Ornithology sought to clarify the status of the species in the U.S. and Canada by using 21 years of citizen science data collected through its Project Feederwatch program.

Project FeederWatch is a winter-long survey of birds that visit feeders at backyards, nature centers, community areas, and other locales. For the study, which was recently published in the Wilson Journal of Ornithology, the research team reviewed recorded observations of house sparrows during their non-breeding season. These sightings from nearly 12,500 sites were used and cross-referenced with the National Land Cover database to determine whether the U.S. sightings came from rural or urban locations.

From 1995 to 2016, researchers found that Feederwatch sites reporting house sparrows declined 7.5%, and the mean flock sizes declined 22%. House sparrow populations declined in urban areas, but actually remained stable in rural areas.

The researchers say a lack of green space and nesting sites in urban areas are likely factors in the population declines.

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Study finds even the common house sparrow is declining

Nearly 3 Billion Birds Gone

Photo, posted May 14, 2014, courtesy of Jacob Spinks via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cooling Down Urban Heat Islands

November 6, 2019 By EarthWise Leave a Comment

Researchers have known about and studied the urban heat island effect for quite some time. Since large cities began to emerge in the 19th century, it has been understood that various aspects of the urban environment lead to warmer temperatures than the surrounding countryside.

Researchers led by a group at Portland State University in Oregon have been utilizing a new way of studying the urban heat island effect. They have used citizen science volunteers in 24 cities around the world to map temperatures in the cities at ground level in great detail using mobile sensors attached to slow-moving vehicles. Previous studies have used data from satellite or stationary sensors. They have learned that the urban heat island effect is more complicated, more varied, and subtler than the earlier data indicated.

They found that there are six things that affect urban heat. Three are living — the volume of the tree canopy, the height of the tree canopy, and the ground level vegetation. Three are human-built — the volume of buildings, the difference in building heights, and the coloring of the buildings.

Buildings can have both negative and positive effects. Tall buildings that cast shade actually lower relative afternoon temperatures, while densely packed shorter buildings, like the big-box stores in suburban areas, lead to hotter afternoon temperatures. The studies show that increasing the difference in building heights in an area creates more air circulation, which has a cooling effect.

The study also showed that urban heat is a social justice issue. Lower-income neighborhoods largely barren of trees have considerably higher temperatures than more affluent, tree-shaded areas.

Such detailed research can be used to guide decisions in urban planning with regard to trees, building heights, and the color and type of surfaces in our urban spaces.

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Can We Turn Down the Temperature on Urban Heat Islands?

Photo, posted July 21, 2009, courtesy of Daniel Dionne via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mobile Apps Empower Citizen Science

June 1, 2016 By WAMC WEB

Citizen scientists play a vital role in raising awareness about the health of our nation’s freshwater resources. Their efforts can help document water clarity and track harmful algal blooms and other indicators of poor water quality instrumental to sound management.