Building Collisions by Bird Species in Chicago and Cleveland
Whitney Wood and Amanda Fadil
2025-04-29
Part 1 - Introduction
As infrastructure and buildings continue to be constructed, we need to address the impact it can have on the environment, specifically, on birds. Birds are important as they eat insects and dispense seeds of various plants (O’Toole, 2024). If these seeds were not dispersed, this would allow for wind-pollinated invasive plant species to overrun (O’Toole, 2024). The data collection is using 40 years of building collision records of birds from Chicago, Illinois, and Cleveland, Ohio (Winger, et al., 2019). Data was collected manually by walking around buildings in Spring and late Autumn to recover the corpses of the birds from building collisions (Winger, et al., 2019). In Ohio, this was done with a focus on migratory birds during a migratory period (Winger, et al., 2019). This was done by various volunteer organizations and museums to monitor the rate of collisions to advocate for change (Winger, et al., 2019).
“This is an image of the Zonotrichia albicollis,
better known as white-throated sparrow (All About Birds, 2025). This
species had the highest collision rate of any species observed in this
data set.”
Are some species of birds more susceptible to collisions than other species of birds with buildings in Chicago and Cleveland?
Information About Our Data Set: The categorical variable we are exploring is the species of birds found after collision. We are comparing the distribution of how many birds from each species experienced collisions with buildings. From this we hope to determine if there is a difference in the collision rate per species.
Part 2 - Exploring the Data (Descriptive Statistics)
Calling in the data set and grouping genus and species for a full scientific name.
#View the structure of the dataset
head(bird_collisions)## # A tibble: 6 × 8
## genus species date locality family flight_call habitat stratum
## <chr> <chr> <date> <chr> <chr> <chr> <chr> <chr>
## 1 Passerculus sandwichen… 1978-10-27 MP Passe… Yes Open Lower
## 2 Passerculus sandwichen… 1979-10-23 MP Passe… Yes Open Lower
## 3 Passerculus sandwichen… 1980-04-19 MP Passe… Yes Open Lower
## 4 Passerculus sandwichen… 1981-09-23 MP Passe… Yes Open Lower
## 5 Passerculus sandwichen… 1982-05-20 MP Passe… Yes Open Lower
## 6 Passerculus sandwichen… 1982-09-18 MP Passe… Yes Open Lower#Bind the genus and species for a full scientific species name
df_united <- unite(bird_collisions, species_name, genus, species, sep = " ")
#View the altered data set
View(df_united)Creating a table for our updated data set with columns for species name, family, habitat, number of collisions, and the frequency rate for number of collisions per the entire data set.
# Making a data table
bird_table<-df_united%>%
group_by(species_name) %>%
select(species_name,family,habitat)%>%
mutate(species_count=n())%>%
arrange(desc(species_count))
bird_table## # A tibble: 69,695 × 4
## # Groups: species_name [88]
## species_name family habitat species_count
## <chr> <chr> <chr> <int>
## 1 Zonotrichia albicollis Passerellidae Forest 10133
## 2 Zonotrichia albicollis Passerellidae Forest 10133
## 3 Zonotrichia albicollis Passerellidae Forest 10133
## 4 Zonotrichia albicollis Passerellidae Forest 10133
## 5 Zonotrichia albicollis Passerellidae Forest 10133
## 6 Zonotrichia albicollis Passerellidae Forest 10133
## 7 Zonotrichia albicollis Passerellidae Forest 10133
## 8 Zonotrichia albicollis Passerellidae Forest 10133
## 9 Zonotrichia albicollis Passerellidae Forest 10133
## 10 Zonotrichia albicollis Passerellidae Forest 10133
## # ℹ 69,685 more rowsbird_table1<-aggregate(x = list(Count = bird_table$species_name),
by = list(Species = bird_table$species_name,
Family = bird_table$family,
Habitat = bird_table$habitat),
FUN = length)
bird_table1<-bird_table1[order(bird_table1$Species), ]
bird_table1## Species Family Habitat Count
## 79 Ammodramus savannarum Passerellidae Open 106
## 36 Cardellina canadensis Parulidae Forest 241
## 8 Cardellina pusilla Parulidae Edge 185
## 63 Catharus fuscescens Turdidae Forest 727
## 64 Catharus guttatus Turdidae Forest 3729
## 65 Catharus minimus Turdidae Forest 822
## 66 Catharus ustulatus Turdidae Forest 2331
## 35 Certhia americana Certhiidae Forest 2676
## 85 Cistothorus palustris Troglodytidae Open 91
## 86 Cistothorus platensis Troglodytidae Open 60
## 28 Contopus cooperi Tyrannidae Edge 4
## 68 Contopus virens Tyrannidae Forest 70
## 6 Dumetella carolinensis Mimidae Edge 599
## 69 Empidonax flaviventris Tyrannidae Forest 68
## 29 Empidonax minimus Tyrannidae Edge 96
## 87 Empidonax traillii Tyrannidae Open 177
## 70 Empidonax virescens Tyrannidae Forest 7
## 37 Geothlypis formosa Parulidae Forest 16
## 9 Geothlypis philadelphia Parulidae Edge 430
## 78 Geothlypis trichas Parulidae Open 1555
## 67 Hylocichla mustelina Turdidae Forest 500
## 5 Icteria virens Icteriidae Edge 15
## 3 Icterus galbula Icteridae Edge 83
## 4 Icterus spurius Icteridae Edge 6
## 18 Junco hyemalis Passerellidae Edge 6303
## 77 Lanius excubitor Laniidae Open 1
## 80 Melospiza georgiana Passerellidae Open 4910
## 19 Melospiza lincolnii Passerellidae Edge 2029
## 20 Melospiza melodia Passerellidae Edge 5124
## 38 Mniotilta varia Parulidae Forest 620
## 30 Myiarchus crinitus Tyrannidae Edge 28
## 39 Oporornis agilis Parulidae Forest 365
## 10 Oreothlypis celata Parulidae Edge 227
## 11 Oreothlypis peregrina Parulidae Edge 2515
## 40 Oreothlypis ruficapilla Parulidae Forest 1690
## 41 Parkesia motacilla Parulidae Forest 15
## 42 Parkesia noveboracensis Parulidae Forest 916
## 81 Passerculus sandwichensis Passerellidae Open 274
## 21 Passerella iliaca Passerellidae Edge 2443
## 1 Passerina caerulea Cardinalidae Edge 1
## 2 Passerina cyanea Cardinalidae Edge 725
## 32 Pheucticus ludovicianus Cardinalidae Forest 397
## 22 Pipilo erythrophthalmus Passerellidae Edge 82
## 33 Piranga olivacea Cardinalidae Forest 127
## 34 Piranga rubra Cardinalidae Forest 9
## 58 Polioptila caerulea Polioptilidae Forest 6
## 82 Pooecetes gramineus Passerellidae Open 10
## 43 Protonotaria citrea Parulidae Forest 6
## 59 Regulus calendula Regulidae Forest 416
## 60 Regulus satrapa Regulidae Forest 1029
## 31 Sayornis phoebe Tyrannidae Edge 24
## 44 Seiurus aurocapilla Parulidae Forest 4580
## 45 Setophaga americana Parulidae Forest 59
## 46 Setophaga caerulescens Parulidae Forest 183
## 47 Setophaga castanea Parulidae Forest 287
## 48 Setophaga cerulea Parulidae Forest 3
## 49 Setophaga citrina Parulidae Forest 5
## 50 Setophaga coronata Parulidae Forest 887
## 51 Setophaga fusca Parulidae Forest 201
## 52 Setophaga magnolia Parulidae Forest 1224
## 12 Setophaga palmarum Parulidae Edge 694
## 13 Setophaga pensylvanica Parulidae Edge 303
## 14 Setophaga petechia Parulidae Edge 77
## 53 Setophaga pinus Parulidae Forest 49
## 15 Setophaga ruticilla Parulidae Edge 868
## 54 Setophaga striata Parulidae Forest 787
## 55 Setophaga tigrina Parulidae Forest 182
## 56 Setophaga virens Parulidae Forest 223
## 61 Sitta canadensis Sittidae Forest 260
## 83 Spizella pallida Passerellidae Open 50
## 23 Spizella passerina Passerellidae Edge 68
## 84 Spizella pusilla Passerellidae Open 325
## 24 Spizelloides arborea Passerellidae Edge 1262
## 76 Sturnella magna Icteridae Open 13
## 7 Toxostoma rufum Mimidae Edge 166
## 27 Troglodytes aedon Troglodytidae Edge 104
## 62 Troglodytes hiemalis Troglodytidae Forest 474
## 88 Tyrannus tyrannus Tyrannidae Open 4
## 16 Vermivora chrysoptera Parulidae Edge 53
## 17 Vermivora cyanoptera Parulidae Edge 16
## 71 Vireo flavifrons Vireonidae Forest 12
## 72 Vireo gilvus Vireonidae Forest 2
## 73 Vireo olivaceus Vireonidae Forest 133
## 74 Vireo philadelphicus Vireonidae Forest 12
## 75 Vireo solitarius Vireonidae Forest 18
## 57 Zonotrichia albicollis Passerellidae Forest 10133
## 25 Zonotrichia leucophrys Passerellidae Edge 1090
## 26 Zonotrichia querula Passerellidae Edge 2#Calculating proportions
per_species <- df_united%>% group_by(species_name) %>% tally()
per_species## # A tibble: 88 × 2
## species_name n
## <chr> <int>
## 1 Ammodramus savannarum 106
## 2 Cardellina canadensis 241
## 3 Cardellina pusilla 185
## 4 Catharus fuscescens 727
## 5 Catharus guttatus 3729
## 6 Catharus minimus 822
## 7 Catharus ustulatus 2331
## 8 Certhia americana 2676
## 9 Cistothorus palustris 91
## 10 Cistothorus platensis 60
## # ℹ 78 more rowsfreq_species<-((per_species$n)/69695)
freq_species## [1] 1.520913e-03 3.457924e-03 2.654423e-03 1.043116e-02 5.350456e-02
## [6] 1.179425e-02 3.344573e-02 3.839587e-02 1.305689e-03 8.608939e-04
## [11] 5.739293e-05 1.004376e-03 8.594591e-03 9.756797e-04 1.377430e-03
## [16] 2.539637e-03 1.004376e-04 2.295717e-04 6.169740e-03 2.231150e-02
## [21] 7.174116e-03 2.152235e-04 1.190903e-03 8.608939e-05 9.043690e-02
## [26] 1.434823e-05 7.044982e-02 2.911256e-02 7.352034e-02 8.895904e-03
## [31] 4.017505e-04 5.237105e-03 3.257049e-03 3.608580e-02 2.424851e-02
## [36] 2.152235e-04 1.314298e-02 3.931415e-03 3.505273e-02 1.434823e-05
## [41] 1.040247e-02 5.696248e-03 1.176555e-03 1.822225e-03 1.291341e-04
## [46] 8.608939e-05 1.434823e-04 8.608939e-05 5.968864e-03 1.476433e-02
## [51] 3.443576e-04 6.571490e-02 8.465457e-04 2.625726e-03 4.117942e-03
## [56] 4.304469e-05 7.174116e-05 1.272688e-02 2.883995e-03 1.756224e-02
## [61] 9.957673e-03 4.347514e-03 1.104814e-03 7.030633e-04 1.245427e-02
## [66] 1.129206e-02 2.611378e-03 3.199656e-03 3.730540e-03 7.174116e-04
## [71] 9.756797e-04 4.663175e-03 1.810747e-02 1.865270e-04 2.381806e-03
## [76] 1.492216e-03 6.801062e-03 5.739293e-05 7.604563e-04 2.295717e-04
## [81] 1.721788e-04 2.869646e-05 1.908315e-03 1.721788e-04 2.582682e-04
## [86] 1.453906e-01 1.563957e-02 2.869646e-05#Adding the proportions as a column
bird_table3<-bird_table1%>%
mutate(freq_species)
bird_table3## Species Family Habitat Count freq_species
## 79 Ammodramus savannarum Passerellidae Open 106 1.520913e-03
## 36 Cardellina canadensis Parulidae Forest 241 3.457924e-03
## 8 Cardellina pusilla Parulidae Edge 185 2.654423e-03
## 63 Catharus fuscescens Turdidae Forest 727 1.043116e-02
## 64 Catharus guttatus Turdidae Forest 3729 5.350456e-02
## 65 Catharus minimus Turdidae Forest 822 1.179425e-02
## 66 Catharus ustulatus Turdidae Forest 2331 3.344573e-02
## 35 Certhia americana Certhiidae Forest 2676 3.839587e-02
## 85 Cistothorus palustris Troglodytidae Open 91 1.305689e-03
## 86 Cistothorus platensis Troglodytidae Open 60 8.608939e-04
## 28 Contopus cooperi Tyrannidae Edge 4 5.739293e-05
## 68 Contopus virens Tyrannidae Forest 70 1.004376e-03
## 6 Dumetella carolinensis Mimidae Edge 599 8.594591e-03
## 69 Empidonax flaviventris Tyrannidae Forest 68 9.756797e-04
## 29 Empidonax minimus Tyrannidae Edge 96 1.377430e-03
## 87 Empidonax traillii Tyrannidae Open 177 2.539637e-03
## 70 Empidonax virescens Tyrannidae Forest 7 1.004376e-04
## 37 Geothlypis formosa Parulidae Forest 16 2.295717e-04
## 9 Geothlypis philadelphia Parulidae Edge 430 6.169740e-03
## 78 Geothlypis trichas Parulidae Open 1555 2.231150e-02
## 67 Hylocichla mustelina Turdidae Forest 500 7.174116e-03
## 5 Icteria virens Icteriidae Edge 15 2.152235e-04
## 3 Icterus galbula Icteridae Edge 83 1.190903e-03
## 4 Icterus spurius Icteridae Edge 6 8.608939e-05
## 18 Junco hyemalis Passerellidae Edge 6303 9.043690e-02
## 77 Lanius excubitor Laniidae Open 1 1.434823e-05
## 80 Melospiza georgiana Passerellidae Open 4910 7.044982e-02
## 19 Melospiza lincolnii Passerellidae Edge 2029 2.911256e-02
## 20 Melospiza melodia Passerellidae Edge 5124 7.352034e-02
## 38 Mniotilta varia Parulidae Forest 620 8.895904e-03
## 30 Myiarchus crinitus Tyrannidae Edge 28 4.017505e-04
## 39 Oporornis agilis Parulidae Forest 365 5.237105e-03
## 10 Oreothlypis celata Parulidae Edge 227 3.257049e-03
## 11 Oreothlypis peregrina Parulidae Edge 2515 3.608580e-02
## 40 Oreothlypis ruficapilla Parulidae Forest 1690 2.424851e-02
## 41 Parkesia motacilla Parulidae Forest 15 2.152235e-04
## 42 Parkesia noveboracensis Parulidae Forest 916 1.314298e-02
## 81 Passerculus sandwichensis Passerellidae Open 274 3.931415e-03
## 21 Passerella iliaca Passerellidae Edge 2443 3.505273e-02
## 1 Passerina caerulea Cardinalidae Edge 1 1.434823e-05
## 2 Passerina cyanea Cardinalidae Edge 725 1.040247e-02
## 32 Pheucticus ludovicianus Cardinalidae Forest 397 5.696248e-03
## 22 Pipilo erythrophthalmus Passerellidae Edge 82 1.176555e-03
## 33 Piranga olivacea Cardinalidae Forest 127 1.822225e-03
## 34 Piranga rubra Cardinalidae Forest 9 1.291341e-04
## 58 Polioptila caerulea Polioptilidae Forest 6 8.608939e-05
## 82 Pooecetes gramineus Passerellidae Open 10 1.434823e-04
## 43 Protonotaria citrea Parulidae Forest 6 8.608939e-05
## 59 Regulus calendula Regulidae Forest 416 5.968864e-03
## 60 Regulus satrapa Regulidae Forest 1029 1.476433e-02
## 31 Sayornis phoebe Tyrannidae Edge 24 3.443576e-04
## 44 Seiurus aurocapilla Parulidae Forest 4580 6.571490e-02
## 45 Setophaga americana Parulidae Forest 59 8.465457e-04
## 46 Setophaga caerulescens Parulidae Forest 183 2.625726e-03
## 47 Setophaga castanea Parulidae Forest 287 4.117942e-03
## 48 Setophaga cerulea Parulidae Forest 3 4.304469e-05
## 49 Setophaga citrina Parulidae Forest 5 7.174116e-05
## 50 Setophaga coronata Parulidae Forest 887 1.272688e-02
## 51 Setophaga fusca Parulidae Forest 201 2.883995e-03
## 52 Setophaga magnolia Parulidae Forest 1224 1.756224e-02
## 12 Setophaga palmarum Parulidae Edge 694 9.957673e-03
## 13 Setophaga pensylvanica Parulidae Edge 303 4.347514e-03
## 14 Setophaga petechia Parulidae Edge 77 1.104814e-03
## 53 Setophaga pinus Parulidae Forest 49 7.030633e-04
## 15 Setophaga ruticilla Parulidae Edge 868 1.245427e-02
## 54 Setophaga striata Parulidae Forest 787 1.129206e-02
## 55 Setophaga tigrina Parulidae Forest 182 2.611378e-03
## 56 Setophaga virens Parulidae Forest 223 3.199656e-03
## 61 Sitta canadensis Sittidae Forest 260 3.730540e-03
## 83 Spizella pallida Passerellidae Open 50 7.174116e-04
## 23 Spizella passerina Passerellidae Edge 68 9.756797e-04
## 84 Spizella pusilla Passerellidae Open 325 4.663175e-03
## 24 Spizelloides arborea Passerellidae Edge 1262 1.810747e-02
## 76 Sturnella magna Icteridae Open 13 1.865270e-04
## 7 Toxostoma rufum Mimidae Edge 166 2.381806e-03
## 27 Troglodytes aedon Troglodytidae Edge 104 1.492216e-03
## 62 Troglodytes hiemalis Troglodytidae Forest 474 6.801062e-03
## 88 Tyrannus tyrannus Tyrannidae Open 4 5.739293e-05
## 16 Vermivora chrysoptera Parulidae Edge 53 7.604563e-04
## 17 Vermivora cyanoptera Parulidae Edge 16 2.295717e-04
## 71 Vireo flavifrons Vireonidae Forest 12 1.721788e-04
## 72 Vireo gilvus Vireonidae Forest 2 2.869646e-05
## 73 Vireo olivaceus Vireonidae Forest 133 1.908315e-03
## 74 Vireo philadelphicus Vireonidae Forest 12 1.721788e-04
## 75 Vireo solitarius Vireonidae Forest 18 2.582682e-04
## 57 Zonotrichia albicollis Passerellidae Forest 10133 1.453906e-01
## 25 Zonotrichia leucophrys Passerellidae Edge 1090 1.563957e-02
## 26 Zonotrichia querula Passerellidae Edge 2 2.869646e-05#Adding a name to the column
colnames(bird_table3)[names(bird_table3)=="freq_species"]<-"species collisions per population"
bird_table3## Species Family Habitat Count
## 79 Ammodramus savannarum Passerellidae Open 106
## 36 Cardellina canadensis Parulidae Forest 241
## 8 Cardellina pusilla Parulidae Edge 185
## 63 Catharus fuscescens Turdidae Forest 727
## 64 Catharus guttatus Turdidae Forest 3729
## 65 Catharus minimus Turdidae Forest 822
## 66 Catharus ustulatus Turdidae Forest 2331
## 35 Certhia americana Certhiidae Forest 2676
## 85 Cistothorus palustris Troglodytidae Open 91
## 86 Cistothorus platensis Troglodytidae Open 60
## 28 Contopus cooperi Tyrannidae Edge 4
## 68 Contopus virens Tyrannidae Forest 70
## 6 Dumetella carolinensis Mimidae Edge 599
## 69 Empidonax flaviventris Tyrannidae Forest 68
## 29 Empidonax minimus Tyrannidae Edge 96
## 87 Empidonax traillii Tyrannidae Open 177
## 70 Empidonax virescens Tyrannidae Forest 7
## 37 Geothlypis formosa Parulidae Forest 16
## 9 Geothlypis philadelphia Parulidae Edge 430
## 78 Geothlypis trichas Parulidae Open 1555
## 67 Hylocichla mustelina Turdidae Forest 500
## 5 Icteria virens Icteriidae Edge 15
## 3 Icterus galbula Icteridae Edge 83
## 4 Icterus spurius Icteridae Edge 6
## 18 Junco hyemalis Passerellidae Edge 6303
## 77 Lanius excubitor Laniidae Open 1
## 80 Melospiza georgiana Passerellidae Open 4910
## 19 Melospiza lincolnii Passerellidae Edge 2029
## 20 Melospiza melodia Passerellidae Edge 5124
## 38 Mniotilta varia Parulidae Forest 620
## 30 Myiarchus crinitus Tyrannidae Edge 28
## 39 Oporornis agilis Parulidae Forest 365
## 10 Oreothlypis celata Parulidae Edge 227
## 11 Oreothlypis peregrina Parulidae Edge 2515
## 40 Oreothlypis ruficapilla Parulidae Forest 1690
## 41 Parkesia motacilla Parulidae Forest 15
## 42 Parkesia noveboracensis Parulidae Forest 916
## 81 Passerculus sandwichensis Passerellidae Open 274
## 21 Passerella iliaca Passerellidae Edge 2443
## 1 Passerina caerulea Cardinalidae Edge 1
## 2 Passerina cyanea Cardinalidae Edge 725
## 32 Pheucticus ludovicianus Cardinalidae Forest 397
## 22 Pipilo erythrophthalmus Passerellidae Edge 82
## 33 Piranga olivacea Cardinalidae Forest 127
## 34 Piranga rubra Cardinalidae Forest 9
## 58 Polioptila caerulea Polioptilidae Forest 6
## 82 Pooecetes gramineus Passerellidae Open 10
## 43 Protonotaria citrea Parulidae Forest 6
## 59 Regulus calendula Regulidae Forest 416
## 60 Regulus satrapa Regulidae Forest 1029
## 31 Sayornis phoebe Tyrannidae Edge 24
## 44 Seiurus aurocapilla Parulidae Forest 4580
## 45 Setophaga americana Parulidae Forest 59
## 46 Setophaga caerulescens Parulidae Forest 183
## 47 Setophaga castanea Parulidae Forest 287
## 48 Setophaga cerulea Parulidae Forest 3
## 49 Setophaga citrina Parulidae Forest 5
## 50 Setophaga coronata Parulidae Forest 887
## 51 Setophaga fusca Parulidae Forest 201
## 52 Setophaga magnolia Parulidae Forest 1224
## 12 Setophaga palmarum Parulidae Edge 694
## 13 Setophaga pensylvanica Parulidae Edge 303
## 14 Setophaga petechia Parulidae Edge 77
## 53 Setophaga pinus Parulidae Forest 49
## 15 Setophaga ruticilla Parulidae Edge 868
## 54 Setophaga striata Parulidae Forest 787
## 55 Setophaga tigrina Parulidae Forest 182
## 56 Setophaga virens Parulidae Forest 223
## 61 Sitta canadensis Sittidae Forest 260
## 83 Spizella pallida Passerellidae Open 50
## 23 Spizella passerina Passerellidae Edge 68
## 84 Spizella pusilla Passerellidae Open 325
## 24 Spizelloides arborea Passerellidae Edge 1262
## 76 Sturnella magna Icteridae Open 13
## 7 Toxostoma rufum Mimidae Edge 166
## 27 Troglodytes aedon Troglodytidae Edge 104
## 62 Troglodytes hiemalis Troglodytidae Forest 474
## 88 Tyrannus tyrannus Tyrannidae Open 4
## 16 Vermivora chrysoptera Parulidae Edge 53
## 17 Vermivora cyanoptera Parulidae Edge 16
## 71 Vireo flavifrons Vireonidae Forest 12
## 72 Vireo gilvus Vireonidae Forest 2
## 73 Vireo olivaceus Vireonidae Forest 133
## 74 Vireo philadelphicus Vireonidae Forest 12
## 75 Vireo solitarius Vireonidae Forest 18
## 57 Zonotrichia albicollis Passerellidae Forest 10133
## 25 Zonotrichia leucophrys Passerellidae Edge 1090
## 26 Zonotrichia querula Passerellidae Edge 2
## species collisions per population
## 79 1.520913e-03
## 36 3.457924e-03
## 8 2.654423e-03
## 63 1.043116e-02
## 64 5.350456e-02
## 65 1.179425e-02
## 66 3.344573e-02
## 35 3.839587e-02
## 85 1.305689e-03
## 86 8.608939e-04
## 28 5.739293e-05
## 68 1.004376e-03
## 6 8.594591e-03
## 69 9.756797e-04
## 29 1.377430e-03
## 87 2.539637e-03
## 70 1.004376e-04
## 37 2.295717e-04
## 9 6.169740e-03
## 78 2.231150e-02
## 67 7.174116e-03
## 5 2.152235e-04
## 3 1.190903e-03
## 4 8.608939e-05
## 18 9.043690e-02
## 77 1.434823e-05
## 80 7.044982e-02
## 19 2.911256e-02
## 20 7.352034e-02
## 38 8.895904e-03
## 30 4.017505e-04
## 39 5.237105e-03
## 10 3.257049e-03
## 11 3.608580e-02
## 40 2.424851e-02
## 41 2.152235e-04
## 42 1.314298e-02
## 81 3.931415e-03
## 21 3.505273e-02
## 1 1.434823e-05
## 2 1.040247e-02
## 32 5.696248e-03
## 22 1.176555e-03
## 33 1.822225e-03
## 34 1.291341e-04
## 58 8.608939e-05
## 82 1.434823e-04
## 43 8.608939e-05
## 59 5.968864e-03
## 60 1.476433e-02
## 31 3.443576e-04
## 44 6.571490e-02
## 45 8.465457e-04
## 46 2.625726e-03
## 47 4.117942e-03
## 48 4.304469e-05
## 49 7.174116e-05
## 50 1.272688e-02
## 51 2.883995e-03
## 52 1.756224e-02
## 12 9.957673e-03
## 13 4.347514e-03
## 14 1.104814e-03
## 53 7.030633e-04
## 15 1.245427e-02
## 54 1.129206e-02
## 55 2.611378e-03
## 56 3.199656e-03
## 61 3.730540e-03
## 83 7.174116e-04
## 23 9.756797e-04
## 84 4.663175e-03
## 24 1.810747e-02
## 76 1.865270e-04
## 7 2.381806e-03
## 27 1.492216e-03
## 62 6.801062e-03
## 88 5.739293e-05
## 16 7.604563e-04
## 17 2.295717e-04
## 71 1.721788e-04
## 72 2.869646e-05
## 73 1.908315e-03
## 74 1.721788e-04
## 75 2.582682e-04
## 57 1.453906e-01
## 25 1.563957e-02
## 26 2.869646e-05#Table of top 10 species represented in the data set
top10_species_table<-filter(bird_table3,per_species$n>2100)
top10_species_table## Species Family Habitat Count
## 1 Catharus guttatus Turdidae Forest 3729
## 2 Catharus ustulatus Turdidae Forest 2331
## 3 Certhia americana Certhiidae Forest 2676
## 4 Junco hyemalis Passerellidae Edge 6303
## 5 Melospiza georgiana Passerellidae Open 4910
## 6 Melospiza melodia Passerellidae Edge 5124
## 7 Oreothlypis peregrina Parulidae Edge 2515
## 8 Passerella iliaca Passerellidae Edge 2443
## 9 Seiurus aurocapilla Parulidae Forest 4580
## 10 Zonotrichia albicollis Passerellidae Forest 10133
## species collisions per population
## 1 0.05350456
## 2 0.03344573
## 3 0.03839587
## 4 0.09043690
## 5 0.07044982
## 6 0.07352034
## 7 0.03608580
## 8 0.03505273
## 9 0.06571490
## 10 0.14539063#Table with vectors per species and frequency of the species
bird_table2<-top10_species_table%>%
select(Species,Count,`species collisions per population`)
bird_table2## Species Count species collisions per population
## 1 Catharus guttatus 3729 0.05350456
## 2 Catharus ustulatus 2331 0.03344573
## 3 Certhia americana 2676 0.03839587
## 4 Junco hyemalis 6303 0.09043690
## 5 Melospiza georgiana 4910 0.07044982
## 6 Melospiza melodia 5124 0.07352034
## 7 Oreothlypis peregrina 2515 0.03608580
## 8 Passerella iliaca 2443 0.03505273
## 9 Seiurus aurocapilla 4580 0.06571490
## 10 Zonotrichia albicollis 10133 0.14539063#Table ordered in descending count
Table.Desc <- bird_table2 %>% arrange(desc(`species collisions per population`))
Table.Desc## Species Count species collisions per population
## 1 Zonotrichia albicollis 10133 0.14539063
## 2 Junco hyemalis 6303 0.09043690
## 3 Melospiza melodia 5124 0.07352034
## 4 Melospiza georgiana 4910 0.07044982
## 5 Seiurus aurocapilla 4580 0.06571490
## 6 Catharus guttatus 3729 0.05350456
## 7 Certhia americana 2676 0.03839587
## 8 Oreothlypis peregrina 2515 0.03608580
## 9 Passerella iliaca 2443 0.03505273
## 10 Catharus ustulatus 2331 0.03344573Part 3 - Statistical Test (Inferential Statistics)
An X^2 goodness-of-fit test was used to compare each bird’s species with the number of building collisions they had. This statistical test was used as we were comparing the distribution of a categorical variable. The assumptions for this test are randomly sampled data, no category with an expected frequency less than one, and no more than 20% of the categories having an expected frequency less than 5 (Whitlock & Schluter, 2015).
H0: The rate of building collisions across different species of birds is the same. HA: The rate of building collisions across different species of birds is not the same.
The relevant statistic for a X^2 goodness-of-fit test is X^2. We are using a p-value of 0.05.
#Observed frequencies of building collisions per bird species
observedfreq<-top10_species_table$Count
observedfreq## [1] 3729 2331 2676 6303 4910 5124 2515 2443 4580 10133#Expected frequencies if there is not a difference between species, all added together should equal 1
expectedfreq<-c(0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1)
#Running an X^2 goodness of fit test
chisq.test(x=observedfreq, p=expectedfreq, correct = FALSE)##
## Chi-squared test for given probabilities
##
## data: observedfreq
## X-squared = 11697, df = 9, p-value < 2.2e-16#Making a table of observed vs. expected frequencies
challengebird<-data.frame(observedfreq, expectedfreq)
challengebird## observedfreq expectedfreq
## 1 3729 0.1
## 2 2331 0.1
## 3 2676 0.1
## 4 6303 0.1
## 5 4910 0.1
## 6 5124 0.1
## 7 2515 0.1
## 8 2443 0.1
## 9 4580 0.1
## 10 10133 0.1rownames(challengebird)<- top10_species_table$speciesBar graph of the data set in descending order of number of collisions per bird species.
#Bar plot color coded by bird species in order of descending count
ggplot(Table.Desc, aes(x= reorder(Species,-Count),y = Count, fill = Species)) +
geom_bar(stat = "identity") +
labs(x = "Species", y = "Count", fill = "Species")+
theme_classic()+
theme(
axis.text.x=element_blank(),
axis.ticks.x=element_blank())+
ggtitle("Top 10 Species Collision Count")
Part 4 - Conclusion
Based on the super low p-value, we can reject the null hypothesis, meaning that different species of birds collide with buildings in Chicago and Cleveland at different rates (X^2 = 11635, df=9, p=2.2e-16).
This is important in knowing which species are more vulnerable to colliding with buildings, because if a species is more prone to collisions, more measures should be adopted to lessen this. In the case of the species with the highest number of collisions, Zonotrichia albicollis or white-throated sparrow, they migrate at night and tend to be drawn to tall, lighted structures, hence, causing more collisions from these birds (All About Birds, 2020). In fact, 1 out of every 3 of these birds have disappeared since 1970 and a huge factor of this is high mortality from building collisions (All About Birds, 2020). They are also the most common species in bird collisions from some studies in Toronto and Manhattan (Fritts, 2022). Moving forward to reduce bird collisions, building updates could include using bird friendly materials, using decals and paint on windows, and turning off lights that are non essential at night (Fritts, 2022).
Some limitations on the analysis is that we only used the top 10 species represented in the data set for clarity. The data was collected from over 40 years in Chicago and Cleveland, so it cannot be applied outside of that city. The data also is birds found dead from collisions around buildings, so if the bird survived or was not reported, it would not make it into the data set.
Overall, our data did match with previous studies involving Zonotrichia albicollis or white-throated sparrows. They tend to have a higher number of collisions than other bird species which was evident in our data table, bar graph, and is supported by our X^2 statistic and p-value.
References
Fritts, Rachel. (2022, March 16). These Seven Bird Species are Most Likely to Collide with Windows. American Bird Conservancy. https://abcbirds.org/blog/frequent-colliders/.
O’Toole, Hillarie. (2024, August 7). Bird Collisions: The Impact of “One”. NYC Bird Alliance. https://nycbirdalliance.org/blog/bird-collisions-the-impact-of-one.
Whitlock, M., & Schluter, D. (2015). The Analysis of Biological Data. Roberts and Company Publishers.
Winger BM, Weeks BC, Farnsworth A, Jones AW, Hennen M, Willard DE. (2019). Nocturnal flight-calling behaviour predicts vulnerability to artificial light in migratory birds. Proceedings of the Royal Society B 286(1900): 20190364. https://doi.org/10.1098/rspb.2019.0364.
(2025). White-throated Sparrow. All About Birds. https://www.allaboutbirds.org/guide/White-throated_Sparrow/photo-gallery/64980381.
(2020, September). Bird Profile: White-Throated Sparrow. All About Birds. https://www.allaboutbirds.org/news/bird-profile-white-throated-sparrow/#:~:text=Population%20Trends,efforts%20in%20other%20major%20cities.