Longest study of Great Lakes region birds finds populations holding steady

Date: July 12, 2016

Source: USDA Forest Service - Northern Research Station

A new USDA Forest Service report documenting an unprecedented effort to inventory birds in the western Great Lakes region and analyze changes in bird populations over the past quarter of a century found that across a trio of national forests, most birds are doing well in terms of both species diversity and population.

Published as General Technical Report NRS-159, "Analysis of Long-term Forest Bird Monitoring Data from National Forests of the Western Great Lakes Region" describes trends and potential drivers in the abundance of bird species. Gerald Niemi of the University of Minnesota-Duluth's Natural Resources Research Institute and Robert Howe of the University of Wisconsin-Green Bay are lead authors of the report with co-author Brian Sturtevant, a research ecologist with the USDA Forest Service's Northern Research Station. An estimated 700 birders have volunteered their time or worked as paid field researchers to inventory bird species for more than 25 years. The report will serve as a useful reference for forest managers identifying how species respond to forest management and what species need attention.

"Forest Service science is contributing to healthy, sustainable forests that are more productive and, ultimately, produce cleaner air and water," said Tony Ferguson, Acting Director of the Northern Research Station and the Forest Products Laboratory. "Forest birds play a vital role in forest stewardship through seed dispersal and insect control, and this research will be a valuable reference for land managers working to protect critical habitat for forest birds."

In the three national forests covered by the inventory -- the Chequamegon-Nicolet National Forest in Wisconsin and the Superior and Chippewa National Forests in Northern Minnesota -- the analysis found overall healthy bird communities that give researchers and policy-makers a degree of optimism. "It paints a picture of fairly healthy bird communities in these forests over two decades of surveys," said Niemi. "It shows that there is tremendous diversity of bird species in the region and emphasizes the importance of national forests to migratory and resident bird species."

Read on …

Blue Tits Provide Insight Into Climate Change, Bird Study Shows

Apr. 15, 2013 — Researchers believe that the size of birds' nests created in response to changing weather patterns may be partly to blame for reproductive failures over the last two years.

An article in the April edition of The Biologist, the Society of Biology's magazine, explains that birds produce different sized nests depending on the weather.

Written by Dr Charles Deeming, senior lecturer at the University of Lincoln and a Fellow of the Society of Biology, the article explains that nests are far more than just a way to hold eggs and chicks.

Dr Deeming said: "Over the past few years scientific interest in nests has increased, with studies ranging from nest composition, construction behaviour and thermal properties to the use of nests as potential signals to mates. We've realised that the factors affecting nest construction are far more complex than we had previously understood."

Dr Deeming's studies of great tits and blue tits breeding in nest boxes at the University's Riseholme Park campus have shed light on how nests are built and how they function.

He found that individual birds can build extremely different nests each year. Cold weather on the days the bird was adding lining to the nest meant they built heavier nests than when the weather was warmer. This suggests that an important function of the nest is to keep the bird warm while it sits on the eggs. Once the nest is lined, the female will lay the first egg, which will be incubated for around two weeks. This means a larger, warmer nest will be important for keeping the bird warm if the weather is cold.

However, as climate change brings more unpredictable weather patterns the way birds construct nests will be affected. In both 2011 and 2012, for example, early spells of warm weather were followed by much lower temperatures.

At Riseholme, this seems to have had devastating effects on reproductive success. Birds building in these early warm periods are likely to construct a light, poorly insulated nest. If the weather subsequently turns cooler, having a poorly insulated nest may have an adverse effect on their reproductive success.

Birds use a wide range of materials in their nests, from moss to sheep's wool, and their availability may also be altered by climate change. Certain plants may go extinct in local areas, so some species could lose a key nesting material.

Dr Mark Downs, chief executive of the Society of Biology, said: "Climate change will have a large effect on our ecosystems and our food production, and Dr Deeming's is one of many studies demonstrating that the effects will be complex and difficult to predict. It is essential that we continue to study how organisms adapt to climate change and how we can best mitigate its effects."

Dr Deeming concludes: "Much more research is needed to determine how local climate affects nest construction. Only then will we start to understand how climate change is likely to affect nest building, and hence reproductive success."

http://www.sciencedaily.com/releases/2013/04/130415124545.htm