Data from: Periodical cicadas suffer legacy effects of century-old forest removal
Data files
Jun 16, 2026 version files 144.19 MB
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Cicada_Chorusing_and_Land_Use.csv
171.48 KB
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Cicada_collections.csv
29.51 KB
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Cicada_Loss_Model.xlsx
169.88 KB
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Cicada_release_notes.csv
2.95 KB
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Cicadas_in_the_News.xlsx
81.97 KB
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Output1930.zip
46.54 MB
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Output2023.zip
97.17 MB
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Preemergence_cicada_tunnels.csv
14.07 KB
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README.md
14.34 KB
Abstract
Periodical cicada (Magicicada spp.) ranges have continued to decline even as their habitat has rebounded from historic lows. This counterintuitive trajectory may be a consequence of Magicicada’s limited dispersal capabilities combined with their requirement that individual host trees survive across decades. Indeed, we find that the presence of Magicicada breeding populations is best predicted by tree cover in 1930, not by present-day tree cover, and that cicadas have largely not recolonized restored habitat even after nearly 100 years. A model based on empirical measures of tree cover turnover and cicada dispersal distances suggests that cicada ranges will continue to decline under nearly all conditions. A managed relocation of 20,126 adult Magicicada failed, reinforcing that dispersal to new sites will be difficult to artificially accelerate. Preservation of habitat across centuries may be the only bollard standing between periodical cicadas and their extinction.
Dataset DOI: 10.5061/dryad.4tmpg4fq8
Description of the data and file structure
Additional files for "Periodical cicadas suffer legacy effects of century-old forest removal"
Authors: Ian Chan, Guerin E. Brown, Fabiola Castaneda-Santiago, Jacky S. Chitty, Tamra A. Elliott, Mattie J. Gose, Charlotte M. Hanfland, Stephen D. Hendrix, Carter R. Leerhoff, Susan K. Meerdink, Adam M. Skibbe, MaKella J. Steffensen, Christian L. Weinrich, Andrew A. Forbes
Cicadas_in_the_News.xlsx
References to Brood XIII periodical cicada emergences in Iowa City, IA newspapers between 1856 and 2007, spanning nine Magicicada generations. Specific mention of emergences in Iowa City are bolded and underlined. Though cicadas are referenced in all nine years, emergences in Iowa City are only noted in 1871, 1888, and 1905, after which references to cicadas are only anticipatory, or emergences are only described as occurring at sites elsewhere in Johnson County.
Column-level metadata
- Brood XIII Emergence Year: Year of a brood XIII emergence for which newspapers were searched.
- Other columns refer to names of newspapers and their years in print.
Preemergence_cicada_tunnels.xlsx
Sampling of Magicicada preemergence tunnel holes at 16 forested sites in Johnson County, IA in spring 2024. Five 1m x 1m quadrats were sampled around deciduous trees estimated to be at least 17 years old. See Fig. 1 for map of locations.
Column-level metadata
- Site #: Site number (referenced in Figure 1 and Table S2); Data Type: Nominal.
- Site: Site acronym. MNRA = MacBride Nature Recreation Area; THF = Two Horse Farm; BG/CW = Big Grove / Cangleska Wakan; TC = Turkey Creek; CD = Coralville Dam; MC = Muddy Creek; OMNW = O'Mara-Newport Woods; BKBW = Bob Kirby's Back Woods; PD/HH = Pappy Dickens / Hickory Hill; UCP = Upper City Park; PP = Peninsula Park; MH/CC = Mormon Handcart / Clear Creek; CHUS = Carver Hawkeye Urban Savanna; WRB = West River Bluffs; WCP = Willow Creek Park; RW = Ryerson's Woods. Data Type: Nominal.
- Date: Date of measurement. Data Type: Continuous.
- GPS (Numeric): Global Positioning System coordinates for each tree. Data Type: Geospatial.
- Elevation (m): Height above sea level in meters. Data Type: Continuous.
- Tree species: Linnean name for the tree species (or genus, if species unknown). Data Type: Categorical.
- DBH: Diameter of tree at breast height in cm. DBH was not measured for all trees, and trees with multiple trunks were not measured. Data Type: Continuous.
- Cicada Holes Quadrat_X: Number of cicada holes measured in each of five 1m by 1m quadrats around the tree. Data Type: Discrete.
- Notes, including undergrowth plants: Information about the undergrowth plants and other characteristics. Data type: String.
Cicada_Chorusing_and_Land_Use.csv
301 Forested sites in Johnson County, IA sampled for male Magicicada chorusing in June 2024. Presence = 1 indicates Magicicada were chorusing at a site; presence = 0 indicates they were not. Columns within each buffer radius around a site indicate the total area, the area of water, area of land, tree cover in 1930, tree cover in 2023, "continuous" (1930-2023) tree cover, and tree cover in the 1836-1859 GLO survey.
Column-level metadata
- Site ID: Site number. Data Type: Nominal.
- Date & Time: Date and time of data collection. Data Type: Continuous.
- Coordinates: GPS coordinates, expressed as latitude and longitude in the WGS84 geodetic datum. Data Type: Geospatial.
- Presence: Presence, or not, of chorusing periodical cicadas. 1 = true, 0 = false. Data Type: Boolean
- All remaining columns are repeated for an "r=X km", where X is the diameter (in km) of a circle around the site.
- Total Area: Total area of the circle around the site at radius x, in square meters. Data Type: Continuous.
- Water Area: Portion of the total area around the site occupied by water, in square meters. Blank cells indicate no water. Data Type: Continuous.
- Land Area: Portion of the total area around the site occupied by land, in square meters. Data Type: Continuous.
- 1930 Area: Portion of the total area around the site occupied by tree cover in 1930, in square meters. Data Type: Continuous.
- 2023 Area: Portion of the total area around the site occupied by tree cover in 2023, in square meters. Data Type: Continuous.
- Cont. Area: Portion of the total area around the site occupied by tree cover in both 1930 and 2023, in square meters. Data Type: Continuous.
- GLO Area: Portion of the total area around the site occupied by tree cover in the GLO survey map, in square meters. Blank cells indicate no tree cover. Data Type: Continuous.
Cicada_Loss_Model.xlsx
Calculations of forest and Magicicada range changes. Each tab represents a different scenario of forest loss and gain, coupled with a dispersal radius for periodical cicadas. All scenarios begin with a forested area with a radius of 10 km (314.16 km2), the entirety of which is occupied by Magicicada.
Scenarios (tabs in .xlsx file)
0.05 km exp; 11,14: Model of change involving a 11.87% forest loss and 14.47% forest gain every 17 years, followed by a dispersal of cicadas 50m from their existing range. Most Magicicada fly less than 50 m net distance across their lifetime (24).
0.149 km exp; 11,14: Model of change involving a 11.87% forest loss and 14.47% forest gain every 17 years, followed by a dispersal of cicadas 149m from their existing range. 149 m was the maximum distance recorded for a mated female Magicicada (24).
0.3 km exp; 11,14: Model of change involving a 11.87% forest loss and 14.47% forest gain every 17 years, followed by a dispersal of cicadas 50m from their existing range.
0.5 km exp; 11,14: Model of change involving a 11.87% forest loss and 14.47% forest gain every 17 years, followed by a dispersal of cicadas 50m from their existing range.
0.1 km exp; 0.5,14: Model of change involving a 0.5% forest loss and 14.5% forest gain every 17 years, followed by a dispersal of cicadas 100m from their existing range.
0.1 km exp; 1,14: Model of change involving a 1% forest loss and 14.5% forest gain every 17 years, followed by a dispersal of cicadas 100m from their existing range.
0.1 km exp; 2,14: Model of change involving a 2% forest loss and 14.5% forest gain every 17 years, followed by a dispersal of cicadas 100m from their existing range.
0.1 km exp; 5,14: Model of change involving a 5% forest loss and 14.5% forest gain every 17 years, followed by a dispersal of cicadas 100m from their existing range.
0.1 km exp; 10,14: Model of change involving a 10% forest loss and 14.5% forest gain every 17 years, followed by a dispersal of cicadas 100m from their existing range.
0.1 km exp; 11,14(pres 90): Model of change involving a 11.9% forest loss and 14.5% forest gain every 17 years for 5 generations, followed by an intervention, following which 90% of all Magicicada-inhabited forest is preserved. Cicada dispersal set at 0.1 km.
0.1 km exp; 11,14(pres 95): Model of change involving a 11.9% forest loss and 14.5% forest gain every 17 years for 5 generations, followed by an intervention, following which 95% of all Magicicada-inhabited forest is preserved. Cicada dispersal set at 0.1 km.
0.1 km exp; 11,14(pres 98): Model of change involving a 11.9% forest loss and 14.5% forest gain every 17 years for 5 generations, followed by an intervention, following which 98% of all Magicicada-inhabited forest is preserved. Cicada dispersal set at 0.1 km.
0.1 km exp; 11,14(pres 100): Model of change involving a 11.9% forest loss and 14.5% forest gain every 17 years for 5 generations, followed by an intervention, following which 100% of all Magicicada-inhabited forest is preserved. Cicada dispersal set at 0.1 km.
0.05 km exp; 13y cicadas: Model of change for a 13-YEAR cicada species, involving a 9% forest loss and 11% forest gain every 13 years, followed by a dispersal of cicadas 50m from their existing range. Most Magicicada fly less than 50 m net distance across their lifetime (24).
0.05 km exp; Annual: Model of change for an ANNUAL cicada species, involving a 0.7% forest loss and 0.8% forest gain every year (the same annual percentages as for the 17-year cicadas, scaled to a single year).
Column-level metadata
- Year: Year of cicada generation (arbitrary, but all models start at 2024)
- Generation: Number of generation, starting with generation 0. Each generation begins with egg hatch and ends with adult dispersal.
- Initial A, total trees: Area of total tree cover at the start of the cicada generation (i.e., egg hatch). Units: Square kilometers.
- Initial A, cicada trees: Area of cicada-occupied tree cover at the start of the generation. Units: Square kilometers.
- Initial A, non-cicada trees: Tree covered area not occupied by cicadas at the start of the generation. Units: Square kilometers.
- A, cicada trees after gen. loss: Area of cicada-occupied tree cover after generational loss of trees. Units: Square kilometers.
- A, total trees after gen. loss: Area of total tree cover after generational loss of tree (not inclusive of gains). Units: Square kilometers.
- A, total trees after gen. increase: Area of total tree cover after generational gain of trees (inclusive of losses). Units: Square kilometers.
- A, cicada trees after dispersal: Area of cicada-occupied tree cover after adult dispersal. Units: Square kilometers.
- % change, cicadas: Percentage change in cicada-occupied tree cover.
Cicada_collections.csv
Collection information for Magicicada later released at Pappy Dickens Preserve. Most collections (~10% of each collection) were subsampled to estimate species and sex ratios in each collection. 548 cicadas were removed from the 5/26 MNRA collections for a separate project and were not released at PD. Collections from 5/30 and 5/31 were kept in a holding facility until 6/2/24, at which point 4,677 living cicadas and 5,078 dead cicadas were released in PD.
Column-level metadata
- Location: Name of site where cicadas were collected. See Preemergence_cicada_tunnels.csv for site locations. Data type: Nominal.
- Date: Date of collection. Data Type: Continuous.
- Time Start: Time the collection effort began. Data Type: Continuous.
- Time End: Time the collection effort ended. Data Type: Continuous.
- Total # of Cicadas: Number of cicadas collected. Date Type: Continuous.
- Subsampled: Indicates whether a subsample of cicadas taken to estimate numbers and sexes of each Magicicada species.
- Total subsampled: Number of cicadas subsampled for sex and species.
- M. cassini (M): Number of male Magicicada cassini in the subsample. "n/a" indicates a subsample was not taken for that collection. Data Type: Continuous.
- M. cassini (F): Number of female Magicicada cassini in the subsample. "n/a" indicates a subsample was not taken for that collection. Data Type: Continuous.
- M. septendecim (M): Number of male Magicicada septendecim in the subsample. "n/a" indicates a subsample was not taken for that collection. Data Type: Continuous.
- M. septendecim (F): Number of female Magicicada septendecim in the subsample. "n/a" indicates a subsample was not taken for that collection. Data Type: Continuous.
- M. septendecula (M): Number of male Magicicada septendecula in the subsample. "n/a" indicates a subsample was not taken for that collection. Data Type: Continuous.
- M. septendecula (F): Number of female Magicicada septendecula in the subsample. "n/a" indicates a subsample was not taken for that collection. Data Type: Continuous.
- Release Date: Date that cicadas were released into Pappy Dickens Preserve. Data Type: Continuous.
Cicada_release_notes.csv
Field notes from Magicicada releases at Pappy Dickens Preserve.
Column-level metadata
- Date: date of release
- # Released: Number of adult Magicicada released on that date
- Cumulative # released: Total number of Magicicada released up to and including that date's release.
- Observations and Notes: Contemporaneous notes taken on site during that day's cicada release.
Output1930.zip and Output2023.zip
Raster Tree Classifications for Johnson County, Iowa (1930 and 2023).
This archive contains two classified raster (trees) datasets derived from aerial imagery of Johnson County, Iowa, for the years 1930 and 2023. Each dataset is stored as a georeferenced TIFF file at 1-meter spatial resolution. Please see the original referencing publication for more information on methods and use.
Contents: two zipped folders
1) Output1930.zip
Description:
Contains the classified raster generated from 1930s aerial imagery.
Format: TIFF (GeoTIFF)
Resolution: 1 x 1 meter
Data type: Unsigned 8-bit integer
Coordinate system: UTM NAD83 Zone 15N
Coverage: Johnson County, Iowa, USA
2) Output2023.zip
Description:
Contains the classified raster generated from 2023 aerial imagery.
Format: TIFF (GeoTIFF)
Resolution: 1 x 1 meter
Data type: Unsigned 8-bit integer
Coordinate system: UTM NAD83 Zone 15N
Coverage: Johnson County, Iowa, USA
Code/software
These datasets are intended for GIS analysis. They can be opened with software such as QGIS, ArcGIS, or any application that supports GeoTIFF format.
Citation
If you use this dataset, we encourage you to cite.
Data Access
Historical Iowa City Newspapers. https://iowacity.historyarchives.online/home. Accessed 2024-2025.
Iowa State University GIS Facility. 2024. “Historical Iowa Aerial Imagery (1936–1941), acquired by the U.S. Department of Agriculture.” Orthoimagery Server, Iowa State University. https://ortho.gis.iastate.edu/arcgis/rest/services/ortho/ortho_1930/ImageServer.
Iowa State University GIS Facility. 2024. “Iowa National Agriculture Imagery Program (NAIP) Aerial Imagery, 2023 Collection, acquired by the U.S. Department of Agriculture.” Orthoimagery Server, Iowa State University. https://ortho.gis.iastate.edu/arcgis/rest/services/ortho/ortho_2023_2025_nc/ImageServer.