{"id":44324,"date":"2026-10-29T07:55:52","date_gmt":"2026-10-29T11:55:52","guid":{"rendered":"https:\/\/www.ecoportal.net\/en\/?p=44324"},"modified":"2026-10-29T07:55:52","modified_gmt":"2026-10-29T11:55:52","slug":"gray-bats-turbine-curtailment-missouri","status":"publish","type":"post","link":"https:\/\/www.ecoportal.net\/en\/gray-bats-turbine-curtailment-missouri\/44324\/","title":{"rendered":"At two Missouri wind farms, microphones monitored endangered gray bats as researchers tested shutdown speeds across 138 turbines"},"content":{"rendered":"

No one watches a wind turbine after sunset. The turbines continue to spin. The bats continue to fly.<\/p>\n

What occurs when both meet in the air is generally apparent by the next day.<\/p>\n

At the North Fork Ridge and Kings Point Wind Farms, researchers applied a different approach.<\/p>\n

Turbine-mounted microphones monitored bat activity while researchers tested different shutdown speeds. The goal was to measure acoustic exposure before collisions occurred<\/strong>.<\/p>\n

An endangered species helped shape the project<\/h2>\n

The project involved the endangered Gray Bat because the study was conducted under a permit concerning that federally protected species.<\/p>\n

One reason the project received approval was its potential to improve protection efforts<\/strong> for a federally endangered species.<\/p>\n

While the Gray Bat spends most of its life in caves, they can travel considerable distances from these caves while searching for food.<\/p>\n

While no turbine needs to kill numerous bats to begin to adversely affect a protected species, the loss of even a few individuals can negatively impact an already fragile population.<\/p>\n

Because of this reality, researchers were attempting to develop a method of quantifying risk directly, rather than solely relying upon post-event assessments.<\/p>\n

How bat sounds became a measure of risk<\/h2>\n

The microphones were not designed to count bats. They were intended to monitor activity immediately adjacent to the rotating blades while they are still in operation.<\/p>\n

Unlike a carcass survey, a turbine-mounted microphone can collect evidence<\/strong> while blades are still moving.<\/p>\n

This approach was described in the study plan developed with the U.S. Fish and Wildlife Service<\/a>.<\/p>\n

If acoustic exposure consistently matched bat mortality rates, it could serve as an indicator of risk.<\/p>\n

Ultimately, findings published in Ecosphere<\/em><\/a> showed that acoustic exposure was closely associated with estimated bat fatalities.<\/p>\n

\"\"<\/p>\n

 <\/p>\n

Small shutdown changes reduced bat exposure<\/h3>\n

Wind turbines do not necessarily have to spin at every single wind speed.<\/p>\n

Operators of turbines may be able to set a higher threshold for the minimum wind speed<\/a> required to generate electricity. If this is done it is called curtailment.<\/span><\/p>\n

When blades are stationary or moving more slowly, the risk of turbine-related bat fatalities can be reduced.<\/p>\n

Although curtailment can reduce bat fatalities, it may also reduce electricity generation<\/strong>.<\/p>\n

Researchers were looking at how changes in “shutdown” or “minimum wind speed” would affect acoustic exposure by bats near wind turbines.<\/p>\n

They found that small changes caused significant reductions in exposure. The greater the shutdown threshold used, the lower the exposure measured.<\/p>\n

The largest gaps appeared during peak activity<\/h2>\n

Bat activity was not uniformly dispersed throughout the year. Some weeks experienced minimal activity while others did not.<\/p>\n

The greatest discrepancies among the results of different curtailment methods existed during periods when bat activity was at its highest. As such, the study provided more applicable information<\/strong> than an overall yearly average.<\/p>\n

Wind farm operators do not require the same curtailment protocol every week of the year.<\/p>\n

Periods involving high levels of bat activity<\/a> present greater risks than periods with lower levels of activity. The recordings showed when those differences emerged and how strongly they affected acoustic exposure.<\/p>\n

Missouri was only the testing ground<\/h3>\n

North Fork Ridge and Kings Point Wind Farms were used for this study. The U.S. Fish and Wildlife Service also evaluated whether Activity-Based Informed Curtailment could be used beyond the study sites.<\/p>\n

Acoustic detection systems mounted on turbines may provide more sensitive and timely feedback than traditional carcass surveys when comparing different curtailment strategies.<\/p>\n

Wind farm operators often need answers long before<\/strong> years of field surveys have accumulated.<\/p>\n

A detector mounted on a turbine cannot prevent a collision. It can only measure what is happening around the blades.<\/p>\n

What it may do is reveal when danger is increasing and whether operational changes are reducing bat fatalities<\/a>.<\/p>\n

For researchers, that possibility was the reason for listening to 138 turbines in the first place.<\/p>\n","protected":false},"excerpt":{"rendered":"

No one watches a wind turbine after sunset. The turbines continue to spin. The bats continue to fly. What occurs when both meet in the air is generally apparent by the next day. At the North Fork Ridge and Kings Point Wind Farms, researchers applied a different approach. Turbine-mounted microphones monitored bat activity while researchers … Read more<\/a><\/p>\n","protected":false},"author":27,"featured_media":44440,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"gray,bats","rank_math_title":"","rank_math_description":"Microphones monitored endangered gray bats as researchers tested turbine shutdown speeds across 138 Missouri wind turbines at two wind farms statewide.","footnotes":""},"categories":[8],"tags":[],"class_list":["post-44324","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-energy"],"_links":{"self":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/44324","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/users\/27"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/comments?post=44324"}],"version-history":[{"count":11,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/44324\/revisions"}],"predecessor-version":[{"id":44516,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/44324\/revisions\/44516"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/44440"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=44324"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=44324"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=44324"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}