Introduction
Figure 1 Little brown bats emerging from their roost on a warm, Connecticut summer evening.
On a warm summer evening in Connecticut, crickets and frogs chirp while fireflies flicker into the night. If you are lucky, you might hear an owl chatter in the distance. Unfortunately for people, the mosquitoes are also out in full force. Not only can mosquito bites be uncomfortable, mosquitos are also capable of spreading viral diseases that can infect humans and other animals. Fortunately, the bats are also out, fluttering and squeaking overhead as they feast on the abundant mosquito and midge population you were just swatting away.
Not long ago, the most abundant bat in the state was Myotis lucifugus, commonly known as the little brown bat. Its range in North America spans from Alaska and Newfoundland along the north, and as far south as Southern California, Northern Arizona, and New Mexico. There are no official population counts, but it is estimated that there were over 6 million individuals of just this one bat species prior to 2006.1 Little brown bats flourished alongside people, often using human structures as roosting locations. In 2008, the species was listed as a conservation priority of least concern. By 2018, it was identified as an endangered species by the International Union for Conservation of Nature (IUCN) as well as by several counties and states, including Connecticut.2 Studies of hibernating bat colonies have revealed thousands of dead bats on the ground, in some cases as much as 95% of the colony was decimated. So, what happened to the bats? Why should we be concerned? How can people help the little brown bat species?
This unit examines the concept of species extinction and the impact it has on other plant and animal populations, with a focus on the little brown bat as a case study. A Yale unit differs from many commercially available educational units. You will not find pages to photocopy as worksheets alongside nifty activities. Instead, you will find detailed background information in conjunction with several effective and thoughtfully chosen teaching strategies and lesson suggestions. It is developed with knowledge gained through personal research while participating in the 2020 Yale National Initiative Caretakers versus Exploiters: Impacting Biodiversity in the Age of Humans seminar led by Dr. Paul Turner, Yale Professor of Ecology and Evolutionary Biology. It is a unit that I have researched, discussed, collaborated on, written, and will also teach. The background content should be a sufficient and significant starting place to help teach the five-unit lessons (approximately five, one-hour sessions).
My target audience for the unit is first grade. Six-year-olds! I teach STEM to K to 4th grade students at a magnet school in New Haven, CT. Students come to me once a week for an hour of hands-on science and engineering focused lessons and experiences based on the Next Generation Science Standards (NGSS). The educational standards I used as the basis of this unit fall under life science for first grade as well as K-2 engineering and design. An annotated list of the standards and how this unit addresses them is included in the appendix of this unit. Many elements of this unit can easily be adapted to any grade level despite it being written for primary grades.
The unit is divided into three sections. The first is a general overview of bat biodiversity with a focus on the role of bats in the ecosystem. The second section is an examination of the threats which bats are facing, such as loss of habitat, disease, climate change, and human-induced hazards. There will be a concentration on the plight of the little brown bat and the reason for the species decline in the Northeast United States. The third section highlights how and why several conservation efforts are being made, including how people can help in their neighborhoods. The unit culminates with the design and construction of a bat roosting box that can be used to promote local bat activity.
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