Why Save a Bug? A (Scientific) Love Letter to the Fireflies of New York City

The following is drawn from a paper written for the class, Animal Welfare: Animals in Science, taught by Professor Becca Franks for New York University’s Master’s program in Animal Studies.

Fireflies are natural magic. The pulse of bioluminescent light emitted by fireflies as a form of mating communication inspires a near-universal sense of wonder. Unfortunately, firefly populations experience a number of growing anthropogenic threats. Still, they find a way to flourish in a number of places, including one seemingly unlikely locale: big, bright, never-sleeping New York City. This is a scientific love letter to fireflies, and an open proposal for a research study geared towards understanding firefly urban ecology, in an attempt to nurture their populations and encourage their continued abundance for generations to come. 

Though known by many names- including lightning bugs, glow-worms, and candle flies (Lewis, 2016)- fireflies are actually beetles (order Coleoptera) in the family Lampyridae. In addition to serving important ecological functions, fireflies have an undeniable aesthetic appeal that makes them a flagship species, one whose protection might help anchor larger conservation efforts. In spite of their ecological significance and appeal, firefly species worldwide face a number of threats, and global populations are believed to be in decline (Fallon et al., 2021). Threats to fireflies will only magnify as human population growth and urbanization increase, but few studies have explored the ecology and welfare of fireflies in urban environments. 

This proposed study aims to understand where and how fireflies fare in urban environments by looking at one the most quintessential urban areas in the world: New York City (NYC). The study will source data from two streams: (1) a survey of firefly activity in pre-selected community gardens found within the five boroughs of New York City (Manhattan, Brooklyn, Queens, the Bronx, and Staten Island) and (2) a citizen science-sourced mapping of firefly sightings elsewhere throughout NYC. Through this data collection, the study aims to (1) use data collected from community gardens and parks to better understand what factors do and do not lead to abundant firefly populations in New York City and (2) use the map of firefly sightings to provide potential locations for subsequent studies aimed at improving firefly habitats in New York City. 

The potential results this study might yield could prove instrumental in (1) cultivating firefly populations within community gardens, parks, backyards, and other outdoor spaces in NYC, (2) using abundant populations to create a firefly ecotourism industry in NYC, (3) templatizing materials and methods for firefly researchers in other parts of the world, whose fireflies of interest are facing similar threats and, perhaps most importantly, (4) improving the lives of individual fireflies.

A brief statement of ethics: No fireflies or other animal species will be harmed during the experiment. Aside from the presence of human observers, this study will be non-invasive. No animals will be obtained as samples, and researchers, volunteers, and citizen scientists will be advised against handling and directly interacting with the fireflies in any way. By its very nature, this experiment aims for the utmost consideration of animal welfare, and hopes that its results will ultimately provide a benefit for firefly populations within and without New York City. 

Fireflies thrive primarily in low-lying moist areas with a clear understory (for ground-dwelling females to see flying males), a closed canopy, and darkness.  New York City (NYC) is uniquely situated in the Northeastern USA, a region known to be a firefly hotspot, and New York state itself has been reported as having between 33-53 species of firefly (C.E Fallon et al., 2019). As such, NYC presents a unique opportunity to understand how urbanization has affected a region that typically provides a robust habitat for fireflies. 

Fireflies have been observed in numerous locations around New York City (NYC). While proximity to light sources and other forms of human activity and disturbance vary, these fireflies were observed mostly in small gardens and public parks. Therefore, this proposed study will select community gardens in NYC as the field sites for observations. Urban community gardens offer an opportunity for researchers to assess an ecosystem that is (1) rich with plant life and other ecosystem elements found in parks and small gardens, (2) enclosed within an urban environment, and (3) easily accessible for researchers and volunteers. A fourth consideration could be malleability: community gardens may be modified in the future in order to better suit firefly welfare. 

GreenThumb, a division of the NYC Parks Department, provides programming and material support to over 550 community gardens throughout NYC (Source: GreenThumb). These volunteer-run gardens are located in each of the five boroughs and support a variety of uses- from green spaces meant for relaxation to meeting spaces, full-fledged farms, and everything in between. 

In anticipation of a coming summer (i.e., beginning in February or March), an initial email blast will be sent to GreenThumb’s listserv- that is, every community garden that has a volunteer or representative with an active email address. This preliminary email will ask (a) if any fireflies were spotted in their garden within the past two summers and (b) if they would be open to taking part in a study to assess the state of firefly populations in New York City. 

Out of the responders who are willing to take part in the study, a total of twenty (20) gardens will be selected, ten (10) of which will be gardens where fireflies have been sighted within the past two years, and ten (10) of which will be gardens where fireflies have not been sighted. Two (2) of each type of garden will be selected for each of the five boroughs (Manhattan, Brooklyn, Queens, the Bronx, and Staten Island) (4 gardens total per burrough).

Prior to commencing observational research, preliminary surveys will be conducted for each garden, including interviews with the volunteer(s) who run them. The surveys and interviews will gather an inventory of data including, but not necessarily limited to: the plant life in the garden, light sources, light pollution and its wavelengths, additional animal life that frequents the garden, current garden maintenance practices, land-use history, pesticide and fertilizer treatment, soil quality, elevation, air quality, and characteristics of the surrounding area outside of the garden (e.g., level of human activity, and other notable factors). 

Then, observational data will be collected twice weekly by researchers and/or community garden volunteers over a two-month period, from July 1st through August 31st, during the summer months when fireflies are most abundant. Data will be collected within the gardens from 19:00-21:00 Eastern Time (from dusk to nightfall, when fireflies are most active). In the event of inclement weather or other unforeseen hindrances, no data will be recorded, and those days will be reported as such. 

For each biweekly observation session, researchers and/or volunteers will adhere to a form questionnaire, in which they will record: date and time of observation, habitat notes (any notable changes or deviations from the previous week), temperature, precipitation, wind, cloud cover, and artificial light sources. For firefly data collection, observers will note the number of flashing fireflies that they witness over the course of three ten-second periods, repeated once every fifteen (15) minutes. Additionally, observers will note the number of different flashing patterns, as well as the most common flash pattern. Space will be provided for any additional notes of interest. 

In addition to the aforementioned experimental plots (the community gardens), less formal and more anecdotal, citizen science evidence will be gathered in an attempt to widen the field of vision for potential firefly habitats. Citizen science to track firefly populations has already proven fruitful (Chow & White, 201), and several prominent institutions, such as the Massachusetts Audubon Society have their own citizen science firefly watching initiatives in place (Source: MassAudubon). This study’s citizen science data will be collected both passively and actively from July 1st through August 31st, and will comprise the following: 

A weekly scan of four major social media platforms (Facebook, Instagram, Twitter, and TikTok) will aim to identify any and all local posts regarding firefly sightings. Wherever possible, sightings will be geolocated, and further details will be gathered, based on the individual social media user’s willingness to share information. 

In addition to scanning social media, the study will actively solicit field reports from citizen scientists using an online survey submission form. This online survey will ask ordinary citizens who happen to see fireflies to submit any and all observations that they can make. Survey questions will include: date, precise location, habitat type (e.g., open field in public park, wooded area of park, etc.), temperature, precipitation, wind, cloud cover, and any artificial light sources present. Included in the form will be a link to a firefly observation key, should the participants be willing and able to observe flash frequencies and types. While all data will be valuable, the two most essential factors (and the easiest) to gather are date, time, and precise geographic location. 

In order to aid in this process, several promotional endeavors will be undertaken. Flyers will be printed and canvassed around public parks and a predetermined cross section of neighborhoods, especially those with large amounts of backyard gardens. Email and social media blasts, as well as door-to-door canvassing, will attempt to inform as many New Yorkers as possible about the program. Social media posts and email blasts will include a link to the survey form. Printed flyers will include a scannable QR code that will link an observer’s mobile phone directly to the survey. In approaching various interest groups, particular attention will be paid to notifying public parks and select “outdoors” groups (e.g., birders, club sports teams)- those people who are most likely to encounter fireflies.

A foundational source of data for this study will be its firefly counts. That is, in which gardens do fireflies live, how many fireflies are there, and when do they appear in highest (and lowest) numbers over the course of two months? 

Furthermore, each community garden will have been surveyed for its plant life, light sources, light pollution and its wavelengths, additional animal life that frequents the garden, current garden maintenance practices, land-use history, pesticide and fertilizer treatment, soil quality, elevation, air quality, and characteristics of the surrounding area outside of the garden (e.g., level of human activity, and other notable factors). 

The most clear observations that can be assessed will be the distinctions between gardens that have fireflies, and those that do not. From there, we may be able to investigate more subtle nuances between the gardens that do have fireflies. Given the breadth of data collected, any number of patterns may emerge, and will require a rigorous statistical analysis. For example, community gardens with a history of pesticide use and/or industrial use may support fewer (or no) fireflies. Similar observations can be made for soil and air quality, as well as the presence or absence of prey and predator species. Perhaps community gardens with human-made ponds and fountains will support a more robust population of fireflies, and perhaps those at higher elevations will support fewer of them. 

For the purposes of the present proposal, we consider two potentially significant pieces of data: artificial light at night (ALAN) and plant species. To what extent did ALAN affect the quantities of fireflies and their number of appearances? Were there certain wavelengths that appeared to affect fireflies more than others? With regard to plants, were there any notable botanical commonalities between high- and low-firefly zones?

While the survey distributed to citizen scientists will ask a number of observational questions, the primary goal of the citizen science component of this paper will be to geolocate any and all locations where fireflies are spotted in New York City. Therefore, one of the more fruitful data displays will come in the form of maps of each of the five boroughs of New York City, with the locations and frequencies of firefly observations indicated. 

Though fireflies exist in a wide range of habitats, common ecological denominators of such locations include the presence of moisture and rich organic matter. Ideal habitats, for example, could be forested areas near water, interdunal freshwater depressions, grasslands, and even desert canyons. Their most acute threats include light pollution, habitat degradation and loss, pesticide use, climate change, introduced species, disturbance from tourism, and commercial harvesting and overcollection (C. Fallon et al., 2019).

Preliminary research provides illustrations that the more urban and light-polluted an environment gets, the fewer fireflies there are (Picchi et al., 2013). Numerous other studies indicate that artificial light at night (ALAN) has adverse effects on firefly fitness. Light pollution has the potential to decrease courtship and mating behavior between male and female fireflies (Firebaugh & Haynes, 2019). It may do this by reducing flashing activities among courting males and females (Firebaugh & Haynes, 2016). Light pollution also has adverse effects on firefly larvae (Mbugua et al., 2020; Owens & Lewis, 2021). This disturbance is likely due in large part to the similarities between the wavelengths of human-generated light, and those of flashing fireflies (Owens et al., 2018). 

As human populations grow and urbanization increases, the deleterious effects of ALAN and other threats are likely to grow more pronounced. While urban environments like New York City (NYC) are likely to include a number of the threats facing fireflies, ALAN constitutes a particularly clear factor (NYC is, after all, “the city that never sleeps”). Additional studies highlight the growing threat of light pollution, and aim to create frameworks for evaluating such threats in order to assess the vulnerabilities of species facing urbanization (Vaz et al., 2021). Therefore, this proposal has prioritized hypothetical data gathered around the light intensity and wavelength(s) around the community gardens under observation. An additional source of data of interest will be the plant life found in each of the community gardens. As previously mentioned, the amount of organic matter present affects firefly welfare. Furthermore, invasive plants are a significant threat to firefly populations (C. Fallon et al., 2019). 

It is unclear how much observational data will be collected through this study’s citizen science component. While the online survey distributed will include prompts and space for numerous different observations (e.g., weather and temperature), it is anticipated that casual reporters may not always have the time nor interest to put in that much effort. Therefore, this proposal aims to highlight the most significant data point to be gathered from citizen scientists: the precise locations of firefly sightings in NYC. 

One study assessing the state of urban firefly populations in Italy indicates that corridors- areas of suitable habitat connecting populations between uninhabitable areas dominated by human activities or structures- were essential to sustaining firefly populations (Picchi et al., 2013). Such a point hints at the tip of the iceberg of potential utility for this proposed study. 

Data collected from this study could, for example, be used to provide guidelines and tips for cultivating firefly habitats in New York City and other urban environments. The map(s) generated by this proposed study’s citizen science surveys could serve as a springboard into sourcing locations for such an endeavor. In addition to disseminating a sort of “firefly handbook” to parks and community gardens, the information can be circulated around neighborhoods and into the homes of ordinary citizens who have backyards, in an effort to create as many “firefly corridors” as possible in NYC. Additional research could also compare backyards in which citizens cultivate firefly-friendly habitats with control backyards in which there are no such interventions. If these methods are successfully implemented in NYC, perhaps they can be applied to other urban environments where fireflies face similar threats. 

With respect to ALAN, further research can be conducted into wavelengths of light that affect NYC’s firefly populations most acutely. If such wavelengths are determined, that data could pave the way for experiments that test the effects of lights with less intrusive wavelengths on firefly fitness and welfare. Findings from such a report could be used to influence public policy by encouraging public and private buildings to adjust their light sources by, perhaps, adding filters. 

The data gathered in this proposed study’s citizen science facet can be used to assess what it takes to get ordinary citizens involved in conservation efforts. Is there one method of approach and/or marketing that works better than others? How can a study keep potential participants engaged, so as to maximize the amount of data obtained? Answering these questions will lead to improved further studies within NYC, and in other urban settings around the world. In tandem, the survey experience itself can be improved. This proposal currently utilizes a link to an online survey in order to obtain citizen science data, but future studies might benefit from a more streamlined mobile app that allows participants to easily submit their findings, and that better organizes the findings. 

Broader research outside of cities can explore firefly population dynamics, particularly how firefly populations may or may not be able to establish themselves in new locations. If we can understand how fireflies come to populate areas, perhaps we can encourage their re-population in urban environments lacking fireflies. In addition to ALAN, further research could zero in on assessments of individual elements recorded in this proposed study, like insecticide and land use histories. Another future study might work to identify physiological differences between urban, suburban, and rural populations of fireflies in the New York City area and beyond. Do NYC fireflies behave differently from those living in upstate New York? Might there be any subtle differences in the wavelengths of their flashes?

The most idealistic hope for this proposed study is for it to serve as a stepping stone on the way to cultivating firefly ecotourism in New York City. In spite of the threats faced by these animals, firefly tourism is on the rise (Lewis et al., 2021) and could serve as an essential measure in keeping up public awareness of conservation efforts. Starting a firefly ecotourism industry in New York City’s public gardens would be an opportunity to spread the wonder of fireflies to a human population that, for the most part, does not regularly witness them. 

Studying firefly ecology in urban environments can provide insight into how firefly populations must adapt to a world increasingly dominated by human activity. Such data will provide useful guidance for the number of researchers, organizations, and citizen scientists who have devoted their lives to firefly research and conservation, including the Fireflyers International Network, the Xerces Society for Invertebrate Conservation, the Massachusetts Audubon Society, and Firefly.org (Sources: Fireflyers International Network; Xerces Society for Invertebrate Conservation; MassAudubon; Firefly.org). 

The most frequent scientific discussions about fireflies (including the bulk of this proposed study) center on maintenance and survival of their populations. With that said, this proposed study sincerely hopes that any data gathered can be used to respect and appreciate the perspective of an individual firefly. What does it feel like to be a firefly? What is it to find true purpose in the search for a returned flash of light? Imagining the experience of finding a firefly mate through human eyes is dreamlike and surreal- that is, until one considers the threats facing fireflies. Often, the people we love the most appear like lighthouses in an otherwise inhospitable landscape. What must it be like to watch the light of one’s most beloved beacon grow more and more faint? What must it be like to no longer see that beacon at all? 

Shortly before her passing just a few months ago, poet Kamilah Aisha Moon published a poem entitled Fireflies, in which the speaker is transported into the world of these marvelous insects. 

The poem concludes: 

Inside the brightest nook

of themselves, they are

everything they did

right, everything that

made sense at the time

still bringing

residual joy. Ambient,

my parents winged

& lit from every angle

hover, untaxed delight!

I don’t blink, don’t dare

try to capture them

in the mason jar

of my hungers

nor halt them

shimmering, spellbound.

Fireflies are slow and gentle creatures, non-threatening to humans, easy to approach, and even easier to capture, but this accessibility belies their profound vulnerability. As children, we may have captured fireflies in mason jars and wondered at their glow, but it is time to temper our impulse to catch, to obtain, and to covet the things we find beautiful. This study aims to be a step in that direction, towards appreciating the wonder and beauty of a remarkable species, but in a way that respects their autonomy, and that serves as a guide for further research and conservation efforts to do the same. 


Chow, A. T., & White, D. L. (2014). Vanishing fireflies: A citizen-science project promoting scientific inquiry and environmental stewardship. Science Education and Civic Engagement, 6(1). https://www.researchgate.net/publication/260833756

Fallon, C. E., Walker, A. C., Lewis, S., Cicero, J., Faust, L., Heckscher, C. M., Pérez-Hernández, C. X., Pfeiffer, B., & Jepsen, S. (2021). Evaluating firefly extinction risk: Initial red list assessments for North America. PLoS ONE, 16 (11 November 2021). https://doi.org/10.1371/journal.pone.0259379

Fallon, C., Hoyle, S., Lewis, S., Owens, A., Lee-Mäder, E., Black, S. H., & Jepsen, S. (2019). Conserving the Jewels of the Night Guidelines for Protecting Fireflies in the United States and Canada.

Firebaugh, A., & Haynes, K. J. (2016). Experimental tests of light-pollution impacts on nocturnal insect courtship and dispersal. Oecologia, 182(4), 1203–1211. https://doi.org/10.1007/s00442-016-3723-1

Firebaugh, A., & Haynes, K. J. (2019). Light pollution may create demographic traps for nocturnal insects. Basic and Applied Ecology, 34, 118–125. https://doi.org/10.1016/j.baae.2018.07.005

Firefly Conservation & Research, https://www.firefly.org/. Accessed 13 Dec. 2021. 

Fireflyers International Network, https://fireflyersinternational.net/. Accessed 13 Dec. 2021. 

GreenThumb, http://greenthumb.nycgovparks.org. Accessed 13 Dec. 2021. 

Lewis, S. M., Thancharoen, A., Wong, C. H., López‐Palafox, T., Santos, P. V., Wu, C., Faust, L., de Cock, R., Owens, A. C. S., Lemelin, R. H., Gurung, H., Jusoh, W. F. A., Trujillo, D., Yiu, V., López, P. J., Jaikla, S., & Reed, J. M. (2021). Firefly tourism: Advancing a global phenomenon toward a brighter future. Conservation Science and Practice, 3(5). https://doi.org/10.1111/csp2.391

Lewis, Sara. Silent Sparks : The Wondrous World of Fireflies, Princeton University Press, 2016. MassAudubon,https://www.massaudubon.org/get-involved/community-science/firefly-watch. Accessed 13 Dec. 2021. 

Mbugua, S. W., Wong, C. H., & Ratnayeke, S. (2020). Effects of artificial light on the larvae of the firefly Lamprigera sp. in an urban city park, Peninsular Malaysia. Journal of Asia-Pacific Entomology, 23(1), 82–85. https://doi.org/10.1016/j.aspen.2019.10.005

Moon, Kamilah Aisha. “Fireflies.” World Literature Today, https://www.worldliteraturetoday.org/blog/black-voices/fireflies-kamilah-aisha-moon. Accessed 13 Dec. 2021. 

Owens, A. C. S., & Lewis, S. M. (2021). Effects of artificial light on growth, development, and dispersal of two North American fireflies (Coleoptera: Lampyridae). Journal of Insect Physiology, 130. https://doi.org/10.1016/j.jinsphys.2021.104200

Owens, A. C. S., Meyer-Rochow, V. B., & Yang, E. C. (2018). Short- and mid-wavelength artificial light influences the flash signals of Aquatica ficta fireflies (Coleoptera: Lampyridae). PLoS ONE, 13(2). https://doi.org/10.1371/journal.pone.0191576

Picchi, M. S., Avolio, L., Azzani, L., Brombin, O., & Camerini, G. (2013). Fireflies and land use in an urban landscape: The case of Luciola italica L. (Coleoptera: Lampyridae) in the city of Turin. Journal of Insect Conservation, 17(4), 797–805. https://doi.org/10.1007/s10841-013-9562-z

Vaz, S., Manes, S., Gama-Maia, D., Silveira, L., Mattos, G., Paiva, P. C., Figueiredo, M., & Lorini, M. L. (2021). Light pollution is the fastest growing potential threat to firefly conservation in the Atlantic Forest hotspot. Insect Conservation and Diversity, 14(2), 211–224. https://doi.org/10.1111/icad.12481

Xerces Society for Invertebrate Conservation, http://xerces.org. Accessed 13 Dec. 2021.

Cover Photo by Tony Phan on Unsplash

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