The world's population first reached one billion people in 1803, and reach eight billion in 2023, and will peak at almost 11 billion by the end of the century. Although it took thousands of years to reach one billion people, it did so at the beginning of a phenomenon known as the demographic transition; from this point onwards, population growth has skyrocketed, and since the 1960s the population has increased by one billion people every 12 to 15 years. The demographic transition sees a sharp drop in mortality due to factors such as vaccination, sanitation, and improved food supply; the population boom that follows is due to increased survival rates among children and higher life expectancy among the general population; and fertility then drops in response to this population growth. Regional differences The demographic transition is a global phenomenon, but it has taken place at different times across the world. The industrialized countries of Europe and North America were the first to go through this process, followed by some states in the Western Pacific. Latin America's population then began growing at the turn of the 20th century, but the most significant period of global population growth occurred as Asia progressed in the late-1900s. As of the early 21st century, almost two thirds of the world's population live in Asia, although this is set to change significantly in the coming decades. Future growth The growth of Africa's population, particularly in Sub-Saharan Africa, will have the largest impact on global demographics in this century. From 2000 to 2100, it is expected that Africa's population will have increased by a factor of almost five. It overtook Europe in size in the late 1990s, and overtook the Americas a decade later. In contrast to Africa, Europe's population is now in decline, as birth rates are consistently below death rates in many countries, especially in the south and east, resulting in natural population decline. Similarly, the population of the Americas and Asia are expected to go into decline in the second half of this century, and only Oceania's population will still be growing alongside Africa. By 2100, the world's population will have over three billion more than today, with the vast majority of this concentrated in Africa. Demographers predict that climate change is exacerbating many of the challenges that currently hinder progress in Africa, such as political and food instability; if Africa's transition is prolonged, then it may result in further population growth that would place a strain on the region's resources, however, curbing this growth earlier would alleviate some of the pressure created by climate change.

The Africa Population (Live) counter shows a continuously updated estimate of the current population of Africa delivered by Worldometer's RTS algorithm, which processes data collected from the United Nations Population Division. From https://www.worldometers.info/world-population/africa-population/

World Population World Population and top 20 Countries Live Clock. Population in the past, present, and future. Milestones. Global Growth Rate. World population by Region and by Religion. Population Density, Fertility Rate, Median Age, Migrants. All-time population total.

This dataset presents the estimated number of live births in each country for the most recent reference year, based on the 2024 revision of the UN Population Division’s World Population Prospects. Live birth estimates are a key demographic indicator, used for planning health services, calculating health coverage indicators, and understanding population growth trends. These figures support maternal and newborn health monitoring and workforce planning at national and global levels.Data Source:UN Population Division World Population Prospects: https://population.un.org/wpp/Download/StandardData Dictionary: The data is collated with the following columns:Column headingContent of this columnPossible valuesRefNumerical counter for each row of data, for ease of identification1+CountryShort name for the country195 countries in total – all 194 WHO member states plus PalestineISO3Three-digit alphabetical codes International Standard ISO 3166-1 assigned by the International Organization for Standardization (ISO). e.g. AFG (Afghanistan)ISO22 letter identifier code for the countrye.g. AF (Afghanistan)ICM_regionICM Region for countryAFR (Africa), AMR (Americas), EMR (Eastern Mediterranean), EUR (Europe), SEAR (South east Asia) or WPR (Western Pacific)CodeUnique project code for each indicator:GGTXXnnnGG=data group e.g. OU for outcomeT = N for novice or E for ExpertXX = identifier number 00 to 30nnn = identifier name eg mmre.g. OUN01sbafor Outcome Novice Indicator 01 skilled birth attendance Short_nameIndicator namee.g. maternal mortality ratioDescriptionText description of the indicator to be used on websitee.g. Maternal mortality ratio (maternal deaths per 100,000 live births)Value_typeDescribes the indicator typeNumeric: decimal numberPercentage: value between 0 & 100Text: value from list of text optionsY/N: yes or noValue_categoryExpect this to be ‘total’ for all indicators for Phase 1, but this could allow future disaggregation, e.g. male/female; urban/ruraltotalYearThe year that the indicator value was reported. For most indicators, we will only report if 2014 or more recente.g. 2020Latest_Value‘LATEST’ if this is the most recent reported value for the indicator since 2014, otherwise ‘No’. Useful for indicators with time trend data.LATEST or NOValueIndicator valuee.g. 99.8. NB Some indicators are calculated to several decimal places. We present the value to the number of decimal places that should be displayed on the Hub.SourceFor Caesarean birth rate [OUN13cbr] ONLY, this column indicates the source of the data, either OECD when reported, or UNICEF otherwise.OECD or UNICEFTargetHow does the latest value compare with Global guidelines / targets?meets targetdoes not meet targetmeets global standarddoes not meet global standardRankGlobal rank for indicator, i.e. the country with the best global score for this indicator will have rank = 1, next = 2, etc. This ranking is only appropriate for a few indicators, others will show ‘na’1-195Rank out ofThe total number of countries who have reported a value for this indicator. Ranking scores will only go as high as this number.Up to 195TrendIf historic data is available, an indication of the change over time. If there is a global target, then the trend is either getting better, static or getting worse. For mmr [OUN04mmr] and nmr [OUN05nmr] the average annual rate of reduction (arr) between 2016 and latest value is used to determine the trend:arr <-1.0 = getting worsearr >=-1.0 AND <=1.0 = staticarr >1.0 = getting betterFor other indicators, the trend is estimated by comparing the average of the last three years with the average ten years ago:decreasing if now < 95% 10 yrs agoincreasing if now > 105% 10 yrs agostatic otherwiseincreasingdecreasing Or, if there is a global target: getting better,static,getting worseNotesClarification comments, when necessary LongitudeFor use with mapping LatitudeFor use with mapping DateDate data uploaded to the Hubthe following codes are also possible values:not reported does not apply don’t knowThis is one of many datasets featured on the Midwives’ Data Hub, a digital platform designed to strengthen midwifery and advocate for better maternal and newborn health services.

The estimated population of the Gaza Strip for 2023 was around 2.1 million people. The Palestinian population of Gaza is relatively young when compared globally. More than half of Gazans are 19 years or younger. This is due to the comparably high fertility rate in the Gaza Strip of *** children per woman as of 2022.

Estimated number of persons by quarter of a year and by year, Canada, provinces and territories.

Over the past 23 years, there were constantly more men than women living on the planet. Of the 8.06 billion people living on the Earth in 2023, 4.05 billion were men and 4.01 billion were women. One-quarter of the world's total population in 2024 was below 15 years.

The world population surpassed eight billion people in 2022, having doubled from its figure less than 50 years previously. Looking forward, it is projected that the world population will reach nine billion in 2038, and 10 billion in 2060, but it will peak around 10.3 billion in the 2080s before it then goes into decline. Regional variations The global population has seen rapid growth since the early 1800s, due to advances in areas such as food production, healthcare, water safety, education, and infrastructure, however, these changes did not occur at a uniform time or pace across the world. Broadly speaking, the first regions to undergo their demographic transitions were Europe, North America, and Oceania, followed by Latin America and Asia (although Asia's development saw the greatest variation due to its size), while Africa was the last continent to undergo this transformation. Because of these differences, many so-called "advanced" countries are now experiencing population decline, particularly in Europe and East Asia, while the fastest population growth rates are found in Sub-Saharan Africa. In fact, the roughly two billion difference in population between now and the 2080s' peak will be found in Sub-Saharan Africa, which will rise from 1.2 billion to 3.2 billion in this time (although populations in other continents will also fluctuate). Changing projections The United Nations releases their World Population Prospects report every 1-2 years, and this is widely considered the foremost demographic dataset in the world. However, recent years have seen a notable decline in projections when the global population will peak, and at what number. Previous reports in the 2010s had suggested a peak of over 11 billion people, and that population growth would continue into the 2100s, however a sooner and shorter peak is now projected. Reasons for this include a more rapid population decline in East Asia and Europe, particularly China, as well as a prolongued development arc in Sub-Saharan Africa.

Infectious diseases can cause steep declines in wildlife populations, leading to changes in genetic diversity that may affect the susceptibility of individuals to infection and the overall resilience of populations to pathogen outbreaks. Here, we examine evidence for a genetic bottleneck in a population of American crows (Corvus brachyrhynchos) before and after the emergence of West Nile virus (WNV). More than 50% of marked birds in this population were lost over the two-year period of the epizootic, representing a 10-fold increase in adult mortality. Using analyses of SNPs and microsatellite markers, we tested for evidence of a genetic bottleneck and compared levels of inbreeding and immigration in the pre- and post-WNV populations. Counter to expectations, genetic diversity (allelic diversity and the number of new alleles) increased after WNV emergence. This was likely due to increases in immigration, as the estimated membership coefficients were lower in the post-WNV population. Simultaneously, however, the frequency of inbreeding appeared to increase: mean inbreeding coefficients were higher among SNP markers, and heterozygosity-heterozygosity correlations were stronger among microsatellite markers, in the post-WNV population. These results indicate that loss of genetic diversity at the population level is not an inevitable consequence of a population decline, particularly in the presence of gene flow. The changes observed in post-WNV crows could have very different implications for their response to future pathogen risks, potentially making the population as a whole more resilient to a changing pathogen community, while increasing the frequency of inbred individuals with elevated susceptibility to disease. Methods Study population and data collection. Crows in the Ithaca, New York, population are cooperative breeders. They live in groups of up to 14 birds, including a socially bonded pair of adults as well as 0-12 auxiliary birds, which are usually offspring from previous broods). Although auxiliaries usually do not contribute offspring to the brood, molecular work in the post-WNV population indicates that auxiliary males occasionally do sire extra-pair offspring with the female breeder, arising both through incest (mothers mating with their adult auxiliary sons) and through matings between non-relatives (e.g., unrelated step-mothers and adult auxiliary males). Genetic samples were collected from crow nestlings from 1990–2011. We collected blood (~150 ul) from the brachial vein of nestlings and banded them with unique combinations of metal bands, color bands, and patagial tags on days 24–30 after hatching. DNA was extracted from samples using DNeasy tissue kits (Qiagen, Valencia, CA) following the manufacturer’s protocol. All fieldwork with American crows was carried out under protocols approved by the Institutional Animal Care and Use Committees of Binghamton University (no. 537-03 and 607-07) and Cornell University (no. 1988–0210). The pre-WNV dataset included samples collected between 1990 and 2002. The 2002 nestlings were sampled prior to WNV emergence, as nestlings fledge the nest between May and July, whereas WNV mortality typically occurs between August and October in this crow population. The post-WNV samples were collected between 2005 and 2011. Samples collected immediately after WNV emergence (2003 and 2004) were not included in the analysis to allow time for the birds to respond to the population loss. We maximized independence of the birds selected for analysis by including only one randomly chosen offspring per brood and no more than two broods per family group in the pre-and post-WNV samples, with each brood per family group separated by the maximum number of years possible within the pre- or post-WNV sampling periods (1990–2002 pre-WNV; 2005–2011 post-WNV; Figure S1). Birds were randomly and independently selected (with replacement) for the SNP and microsatellite analyses; therefore, there was little overlap among individual birds included in these marker sets. Of the 286 individual birds included in this analysis, 22 were common to both marker sets (15 pre-WNV; 7 post-WNV). The 20-year time period of this study may have encompassed 2–4 breeding cohorts (approximately 1–2 pre- and 1–2 post-WNV, with a sharp turn-over immediately after WNV emergence). Crows can produce offspring as early as two years after hatching, but most do not begin breeding independently until at least 3–4 years after hatching. Breeding initiation is limited at least in part by breeding vacancies, which are created by the death of one or both members of an established breeding pair. Such breeding vacancies likely increased in availability after the emergence of WNV. Microsatellite genotyping. A total of 222 crows (n = 113 and 109 crows pre- and post-WNV, respectively) were genotyped at 34 polymorphic microsatellite loci that were optimized for American crows. Alleles were scored using the microsatellite plugin for Geneious 9.1.8. We used GenePop version 4.7 to test for linkage disequilibrium between all pairs of loci, departures from Hardy–Weinberg equilibrium (HWE), and null allele frequency. Locus characteristics (e.g., alleles/ locus, tests of Hardy–Weinberg equilibrium and null allele frequencies) are given in the supplementary materials (Table S1). Departures from HWE expectations were observed at two loci (PnuA3w from the pre-WNV sample and Cb06 from the post-WNV sample) after Bonferroni correction (Table S1); these loci were removed from subsequent analysis. In 561 pairwise comparisons, four pairs of loci appeared to be in linkage disequilibrium (Cb20 and Cb21; Cb14 and CoBr36; CoBr22 and Cb17, and CoBr12 and Cb10), but this linkage was only apparent at both time points (the pre-WNV and post-WNV populations) for Cb20 and Cb21. We removed both Cb20 and Cb21 from the analysis but retained the other loci because apparent linkage at only a single time point was unlikely to be a result of physical linkage. Two additional loci (Cb17 and Cb10) had a high frequency of null alleles (> 0.1) and were removed from the dataset. All subsequent analyses are therefore based on 28 loci. We scored all birds at a minimum of 26 of these 28 loci, and most (>98%) were scored at all loci (mean proportion of loci typed >0.99). Mean allelic diversity at these loci was 11.25 ± 1.17 alleles/locus (range: 3–31 alleles/locus). Double Digest Restriction Associated DNA (ddRAD) sequencing. We performed ddRAD sequencing on 86 randomly selected crows (43 pre-WNV and 43 post-WNV). 100-500 ng of DNA were digested with SbfI-HF (NEB, R3642L) and MspI-HF (NEB, R016S) restriction enzymes. Samples were ligated with a P2-MspI adapter and pooled in groups of 18-20, each with a unique P1 adapter. Pooled index groups were purified using 1.5X volumes of homemade MagNA made with Sera-Mag Magnetic Speed-beads (FisherSci). Fragments 450-600 bp long were selected using BluePippin (Sage Science) by the Cornell University Biotechnology Resource Center (BRC). After size selection, unique index barcodes were added to each index group by performing 11 cycles of PCR with Phusion® DNA polymerase (NEB). Reactions were purified using 0.7X volumes of MagNA beads and pooled in equimolar ratios for sequencing on the Illumina HiSeq 2500 at the BRC, with single end reads (100 bp). The sequencing was performed with an added Illumina PhiX control (15%) due to low 5’ complexity. Pre- and post-WNV samples were library prepared together and sequenced on a single lane to avoid the introduction of a library or lane effect. We used FASTQC v0.11.9 (Babraham Bioinformatics; http://www.bioinformatics.babraham.ac.uk/projects/fastqc/) to assess read quality. We trimmed reads to 147 bp using fastX_trimmer (FASTX-Toolkit) to exclude low-quality data at the 3’ end of reads. Next, we eliminated reads with Phred scores below 10, then eliminated reads in which 5% or more bases had Phred scores below 20 (fastq_quality_filter). The fastq files were demultiplexed using the process_radtags module in STACKS v2.52 pipeline to create a file with sequences specific to each individual. We first scaffolded the American Crow reference genome (NCBI assembly: ASM69197v1, Accession no: GCA_000691975.1) into putative pseudochromosomes using the synteny-based Chromosemble tool in Satsuma2 (Grabherr et al. 2010) and the Hooded Crow genome (NCBI assembly: ASM73873v5, Accession no: GCA_000738735.5). We aligned sequence reads to the American Crow pseudochromosome assembly using BWA-MEM (Li & Durbin 2009). We called SNPs in ANGSD (Korneliussen et al. 2014) using the GATK model, requiring SNPs to be present in 80% of the individuals (0.95 postcutoff, SNP p-value 1e-6) with a minimum allele frequency of 0.015. We removed bases with quality scores below 20 (-minQ 20), bad reads (-remove_bads), mapping quality below 20 (-minMapQ20), base alignment quality below 1 (-baq), more than two alleles (-skipTriallelic), and heterozygote bias (-hetbias_pval 1e-5), requiring the minimum depth per individual to be at least two and read depth higher than 1,800. These filters resulted in 16,200 SNPs. To reduce differences in missingness between the pre- and post-WNV populations, we excluded loci that had less than 80% called genotypes per population, resulting in 5,151 SNPs.

Chart and table of population level and growth rate for the Los Angeles metro area from 1950 to 2025.

Chart and table of population level and growth rate for the state of California from 1900 to 2024.

In 1800, the population of Japan was just over 30 million, a figure which would grow by just two million in the first half of the 19th century. However, with the fall of the Tokugawa shogunate and the restoration of the emperor in the Meiji Restoration of 1868, Japan would begin transforming from an isolated feudal island, to a modernized empire built on Western models. The Meiji period would see a rapid rise in the population of Japan, as industrialization and advancements in healthcare lead to a significant reduction in child mortality rates, while the creation overseas colonies would lead to a strong economic boom. However, this growth would slow beginning in 1937, as Japan entered a prolonged war with the Republic of China, which later grew into a major theater of the Second World War. The war was eventually brought to Japan's home front, with the escalation of Allied air raids on Japanese urban centers from 1944 onwards (Tokyo was the most-bombed city of the Second World War). By the war's end in 1945 and the subsequent occupation of the island by the Allied military, Japan had suffered over two and a half million military fatalities, and over one million civilian deaths.

The population figures of Japan were quick to recover, as the post-war “economic miracle” would see an unprecedented expansion of the Japanese economy, and would lead to the country becoming one of the first fully industrialized nations in East Asia. As living standards rose, the population of Japan would increase from 77 million in 1945, to over 127 million by the end of the century. However, growth would begin to slow in the late 1980s, as birth rates and migration rates fell, and Japan eventually grew to have one of the oldest populations in the world. The population would peak in 2008 at just over 128 million, but has consistently fallen each year since then, as the fertility rate of the country remains below replacement level (despite government initiatives to counter this) and the country's immigrant population remains relatively stable. The population of Japan is expected to continue its decline in the coming years, and in 2020, it is estimated that approximately 126 million people inhabit the island country.

Chart and table of population level and growth rate for the Dubai, UAE metro area from 1950 to 2025.

The statistic shows the total population in Canada from 2020 to 2024, with projections up until 2030. In 2024, the total population in Canada amounted to about 41.14 million inhabitants. Population of Canada Canada ranks second among the largest countries in the world in terms of area size, right behind Russia, despite having a relatively low total population. The reason for this is that most of Canada remains uninhabited due to inhospitable conditions. Approximately 90 percent of all Canadians live within about 160 km of the U.S. border because of better living conditions and larger cities. On a year to year basis, Canada’s total population has continued to increase, although not dramatically. Population growth as of 2012 has amounted to its highest values in the past decade, reaching a peak in 2009, but was unstable and constantly fluctuating. Simultaneously, Canada’s fertility rate dropped slightly between 2009 and 2011, after experiencing a decade high birth rate in 2008. Standard of living in Canada has remained stable and has kept the country as one of the top 20 countries with the highest Human Development Index rating. The Human Development Index (HDI) measures quality of life based on several indicators, such as life expectancy at birth, literacy rate, education levels and gross national income per capita. Canada has a relatively high life expectancy compared to many other international countries, earning a spot in the top 20 countries and beating out countries such as the United States and the UK. From an economic standpoint, Canada has been slowly recovering from the 2008 financial crisis. Unemployment has gradually decreased, after reaching a decade high in 2009. Additionally, GDP has dramatically increased since 2009 and is expected to continue to increase for the next several years.

Number and percentage of live births, by month of birth, 1991 to most recent year.

Chart and table of population level and growth rate for the state of New York from 1900 to 2024.

India birth rate for 2025 is 16.55, a 1.19% decline from 2024.

<ul style='margin-top:20px;'>

<li>India birth rate for 2024 was <strong>16.75</strong>, a <strong>3.74% increase</strong> from 2023.</li>
<li>India birth rate for 2023 was <strong>16.15</strong>, a <strong>1.16% decline</strong> from 2022.</li>
<li>India birth rate for 2022 was <strong>16.34</strong>, a <strong>0.94% decline</strong> from 2021.</li>
</ul>Crude birth rate indicates the number of live births occurring during the year, per 1,000 population estimated at midyear. Subtracting the crude death rate from the crude birth rate provides the rate of natural increase, which is equal to the rate of population change in the absence of migration.

This dataset provides the estimated number of women aged 15–49 years in each country, based on the 2024 revision of the UN Population Division’s World Population Prospects. This age group is commonly defined as women of reproductive age and is used as the denominator in calculating key sexual and reproductive health indicators. These estimates support health system planning, resource allocation, and monitoring of service coverage for women across the reproductive life course.Data Source:UN Population Division’s World Population Prospects: https://population.un.org/wpp/ Data Dictionary: The data is collated with the following columns:Column headingContent of this columnPossible valuesRefNumerical counter for each row of data, for ease of identification1+CountryShort name for the country195 countries in total – all 194 WHO member states plus PalestineISO3Three-digit alphabetical codes International Standard ISO 3166-1 assigned by the International Organization for Standardization (ISO). e.g. AFG (Afghanistan)ISO22 letter identifier code for the countrye.g. AF (Afghanistan)ICM_regionICM Region for countryAFR (Africa), AMR (Americas), EMR (Eastern Mediterranean), EUR (Europe), SEAR (South east Asia) or WPR (Western Pacific)CodeUnique project code for each indicator:GGTXXnnnGG=data group e.g. OU for outcomeT = N for novice or E for ExpertXX = identifier number 00 to 30nnn = identifier name eg mmre.g. OUN01sbafor Outcome Novice Indicator 01 skilled birth attendance Short_nameIndicator namee.g. maternal mortality ratioDescriptionText description of the indicator to be used on websitee.g. Maternal mortality ratio (maternal deaths per 100,000 live births)Value_typeDescribes the indicator typeNumeric: decimal numberPercentage: value between 0 & 100Text: value from list of text optionsY/N: yes or noValue_categoryExpect this to be ‘total’ for all indicators for Phase 1, but this could allow future disaggregation, e.g. male/female; urban/ruraltotalYearThe year that the indicator value was reported. For most indicators, we will only report if 2014 or more recente.g. 2020Latest_Value‘LATEST’ if this is the most recent reported value for the indicator since 2014, otherwise ‘No’. Useful for indicators with time trend data.LATEST or NOValueIndicator valuee.g. 99.8. NB Some indicators are calculated to several decimal places. We present the value to the number of decimal places that should be displayed on the Hub.SourceFor Caesarean birth rate [OUN13cbr] ONLY, this column indicates the source of the data, either OECD when reported, or UNICEF otherwise.OECD or UNICEFTargetHow does the latest value compare with Global guidelines / targets?meets targetdoes not meet targetmeets global standarddoes not meet global standardRankGlobal rank for indicator, i.e. the country with the best global score for this indicator will have rank = 1, next = 2, etc. This ranking is only appropriate for a few indicators, others will show ‘na’1-195Rank out ofThe total number of countries who have reported a value for this indicator. Ranking scores will only go as high as this number.Up to 195TrendIf historic data is available, an indication of the change over time. If there is a global target, then the trend is either getting better, static or getting worse. For mmr [OUN04mmr] and nmr [OUN05nmr] the average annual rate of reduction (arr) between 2016 and latest value is used to determine the trend:arr <-1.0 = getting worsearr >=-1.0 AND <=1.0 = staticarr >1.0 = getting betterFor other indicators, the trend is estimated by comparing the average of the last three years with the average ten years ago:decreasing if now < 95% 10 yrs agoincreasing if now > 105% 10 yrs agostatic otherwiseincreasingdecreasing Or, if there is a global target: getting better,static,getting worseNotesClarification comments, when necessary LongitudeFor use with mapping LatitudeFor use with mapping DateDate data uploaded to the Hubthe following codes are also possible values:not reported does not apply don’t knowThis is one of many datasets featured on the Midwives’ Data Hub, a digital platform designed to strengthen midwifery and advocate for better maternal and newborn health services.

Host movement and spatial structure can strongly influence the ecology and evolution of infectious diseases, with limited host movement potentially leading to high spatial heterogeneity in infection. Monarch butterflies (Danaus plexippus) are best known for undertaking a spectacular long-distance migration in eastern North America; however, they also form non-migratory populations that breed year-round in milder climates such as Hawaii and other tropical locations. Prior work showed an inverse relationship between monarch migratory propensity and the prevalence of the protozoan parasite, Ophryocystis elektroscirrha. Here, we sampled monarchs from replicate sites within each of four Hawaiian Islands to ask whether these populations show consistently high prevalence of the protozoan parasite as seen for monarchs from several other non-migratory populations. Counter to our predictions, we observed striking spatial heterogeneity in parasite prevalence, with infection rates per site ranging from 4–85%. We next used microsatellite markers to ask whether the observed variation in infection might be explained by limited host movement and spatial sub-structuring among sites. Our results showed that monarchs across the Hawaiian Islands form one admixed population, supporting high gene flow among sites. Moreover, measures of individual-level genetic diversity did not predict host infection status, as might be expected if more inbred hosts harbored higher parasite loads. These results suggest that other factors such as landscape-level environmental variation or colonization-extinction processes might instead cause the extreme heterogeneity in monarch butterfly infection observed here.

Annual population estimates as of July 1st, by census metropolitan area and census agglomeration, single year of age, five-year age group and gender, based on the Standard Geographical Classification (SGC) 2021.