Economic or Environmental Migration? The Push Factors in Niger

This paper examines the question of whether humans migrate for purely economic or environmental reasons. Although it is known that both factors impact human behavior, the complex decision calculus of humans makes it complicated to ascertain dominant causes for migration. In Niger, the poorest country out of a list of 182 on the Human Development Index, several important environmental push factors impact life: droughts, soil degradation, the shrinking of Lake Chad, Niger River problems, deforestation, and sand intrusion. These push factors are caused by climate change, regional ecological features, and human activity in the area. The authors of the study concluded that economics was the mechanism through which environmental impacts were felt by migrants, prompting the recommendation of the term “environmentally induced economic migration” to refer to the situation in Niger. –Adriane Holter
Afifi, T., 2011. Economic or Environmental Migration? The Push Factors in Niger. International Migration published ahead of print May 19, 2011,doi:10.1111/j.1468-2435.2010.00644.x

          The sustainability of the environment is a security threat to the estimated 14 million people who live in Niger, because they rely on stable ecological conditions to maintain their livelihoods. With an economy that relies on subsistence crops, livestock, and uranium deposits, Niger’s general population is at risk for destabilization due to rapid climate change. Studying the relationship between the environment, land, and the economy helps develop a more complete picture of the factors that contribute to migration in Niger.
          To study the ways in which economy and environment interact, the Niger researchers combined a study of declining conditions with questionnaires, interviews, and phone calls to experts and migrants in affected areas. For the questionnaires, researchers polled 60 migrant and 20 non-migrant persons in a 2008 field visit to the regions of Niamey and Tillabeeri. Respondents to the research questionnaires revealed that: 90% migrated in part to some environmental consideration, 70% expected future environmental problems to impact them, 50% would migrate for or are currently planning to leave their homes for environmental reasons, and 80% would return to their homes if environmental conditions allowed. Although many of the people the researchers studied did not initially indicate the environment as the main cause of their departure, further examination revealed that economic rationale for migration had a root in environmental issues. For instance, the dwindling water for farmers and herders near Lake Chad directly impacted their economic security and therefore supplied a possible reason for moving. Thus, the term “environmentally induced economic migration” becomes valuable for conceptualizing the real world impacts of climate change.
          Environmentally induced economic migration is a more permanent, uncontrollable situation than the historic cultural practice of seasonal migration in Niger. Furthermore, environmentally induced economic migration induces changes in social dynamics e.g. the organization of food source cooperatives and the selling of labor. Males in some regions depart during the dry season, leaving women and children to undertake the majority of work related to environmental problems. To help counter the social, economic, and security burdens of the people, the researchers recommended several courses of action including: development policies that prevent further environmental degradation, investment in the development of eco-friendly jobs, education campaigns for children and adults, emphasis on indigenous means of coping with environmental security threats, humanitarian aid for people living in abandoned regions, intensification and broadening of the President’s Programme, and increased attention to the re-integration programme started by IOM Niamey for migrants motivated by the environment. 

Soil Quality and Human Migration in Uganda and Kenya

The issues of soil quality impact on humans and environmental migration have been highly debated in the scientific community. However, studies previously conducted on these issues have lacked a large-scale program to monitor soil-degradation. Furthermore, no study has examined economic or social concerns about soil quality outside of agriculture. With the intention to correct these oversights, Gray et al (2011). sought to measure how soil quality impacts internal migration from grain-producing households in the East African Highland countries of Uganda and Kenya. The results of the study show that out-migration from these counties declined with soil quality. Soil quality in Kenya was particularly relevant for migration in small farm households. In Uganda, there was an increase in marginal migration with soil quality, which is consistent with the poverty trap of migration where rural population is large and access to agricultural resources is limited. The authors of the study see their work as a necessary consideration for development policy in Kenya and Uganda. –Adriane Holter
Gray, Clark L., 2011. Soil quality and human migration in Uganda and Kenya. Global Environmental Change 21, 421— 430

          To implement their study, Gray et al. used a longitudinal survey dataset with information collected through the Research on Poverty, Environment, and Agricultural Technology (REPEAT) project. This dataset contained information on migration and soil properties for 1200 households. From this information, the researchers created a household-level measure of soil quality as well as the rate that single persons undertook either temporary or permanent migration. A model of possible random effects tested the effect that soil quality had on migration with a control for household variables.
          In Kenya, soil quality had a negative effect on migration. The likelihood for temporary labor migration was 67% lower and permanent labor migration was 42% less likely to occur when soil quality was high. Researchers found that women or married individuals were the most likely to undertake both temporary and permanent non-labor migration. This result is significant because it highlights how responses to soil degradation have gendered manifestations in society. Multiple attachments to several households as a result of marriage helps explain the increase in migration for married individuals. Additionally, migrants were stratified by age with the largest amount of movement occurring between 25 and 29-years-old except for permanent labor migration, which peaked between 35 and 49-years-old.
          Since Uganda had a smaller sample size than Kenya, the results from the study are not as dramatic. Nevertheless,  research in the country found that soil quality had a marginally positive effect on migration, especially for permanent non-labor migration. There was no clear gender divide for migration, but like Kenya age was also an issue in Uganda with temporary and permanent labor migration peaking between 30 and 34-years-old. Temporary non-labor migration was not affected by age. Also like Kenya, the likelihood of migration increased for married individuals. Importantly, individuals in both countries were less likely to migrate if they had been educated. This information reveals the socio-economic advantage afforded to the educated in the realm of migration, signaling a class-based element of the issue. Additionally, non-labor migration increased with a large number of inhabitants in a household and when the household owned large parcels of land. These results reflect the interplay of resource holdings with the need for human movement to sustain household livelihoods at a desired level. 

Drought and Other Driving Forces behind Population Change in Six Rural Counties in the United States

Although population change in the United States has been widely researched, most studies have focused on social and economic reasons for population shifts. The research that does exist on environmental factors for the most part has looked at temperature and seasonal relationships. To provide more depth to known impact of environment on US population shifts, Maxwell et al. (2011) set the primary research goal of identifying the main reasons for population shifts in six counties in three geographic regions. Secondarily, the researchers were interested in finding the relationship between drought from the 1800s to the present and population change. Furthermore, the study sought to assess the spatial variability between the six locations in the study. The study found that traditional variables for population changeunemployment, education, technological advancement, etc.had the largest impact on population change. Through correlation and regression analysis drought was determined to cause a small variance in population change with significance in three of the six counties. Spatially, without other measures of climatic variables, counties in the same region tended to experience similar results. –Adriane Holter
Maxwell, Justin T., Soule, Peter T., 2011. Drought and Other Driving Forces behind Population Change in Six Rural Counties in the United States. Southeast Geographer 51, 133 – 148

The three regions observed in the study were: the Southeast, Ohio Valley, and Great Plains. The counties within these regions shared similar urban structures and economic makeups. All counties were predominately rural and agricultural. Studied counties did not have a metropolitan center, a highway that passed through the region, corporate owned farms, or substantial irrigation. Per capita income, agricultural prices, and manufacturing prices were acquired from census data and adjusted for inflation in order to analyze economic elements of population change. Additionally, variables such as birth and death rates, educational attainment, and unemployment were standardized by country population in the same year for use in developing a full social picture of each county. Climatic variables were retained from the National Climatic Data Center from 1985 to 2000. Drought was quantified through the study of tree rings in the Palmer Drought Severity Index (PDSI), which included an 11-year moving average to account for the extreme yearly variations in temperature and moisture. A multiple regression model was used to analyze which factors were the biggest drivers for population change in each county.
          In the Southeast, the primary drivers for population change in Sampson County, North Carolina were manufacturing value with other significant factors in agricultural and educational sectors. In Bedford County, South-Central Tennessee the primary drivers were college attainment and temperature, with secondary influencers of agricultural value, manufacturing value, and high school attainment. Drought had a significant impact on population change, while population was inversely related to temperature. Increased level of educational attainment indicated an increase in population. In this area, the intuitive tie between drought and agriculture is evident lower amounts of moisture negatively affect crops.
          In the Ohio Valley, Adams County in Northeast Indiana the most successful model for population change included high school attainment, PDSI, and the death rate. Converse to the findings in the Southeast and Ohio Valley, Pottawatomie County, Northeast Kansas in the Great Plains had a negatively correlated relationship between college attainment and population. Similar to Adams County, PDSI has a significant impact on population change in Pottawatomie. Also in the Great Plains, Tillman County, Southwest Oklahoma had the key population change drivers of high school attainment and death rates with birth rates, college attainment, and annual income also possessing a strong influence. Finally, population change in Douglas County in southeastern South Dakota was most strongly linked to high school attainment and birth rates. Like Tillman County, the levels of death rates, college attainment, and annual income were also important factors.
          The fact that population changes in three of the six counties researched in this study were positively related to the availability of moisture signals the need for more research in the relationship between drought and population size. Currently in the United States, the Southeast and the Southwest have the highest rate of population growth in the country. Furthermore, many of the counties in these regions still rely heavily on agriculture. With the increase in climate change, it is likely that droughts will become more frequent and intense today than the measures found in this study. The relationship between drought and threats to agricultural sustainability make these field a crucial realm of research.

When Nature Rebels: International Migration, Climate Change, and Inequality

By combining economic models with environmental knowledge, the authors of this study sought to create an analysis of international human migration that encompassed policy responses to the issue. A two-country overlapping generations model with endogenous climate change measured on a scale of steady state perspective was used to accomplish this end. The authors summarize their main findings as follows: change in climate creates an increase in migration, small levels of climate change result in substantial impacts on the number of migrants, northern immigration policies have the potential to impact long-run migration thus impacting regional inequality, and finally that green technology decreases emissions and long-run migration where the migrant impact to climate change is significant. A consideration of how values of inequality, wealth, environment, and migration numbers impact policy development is also widely discussed. Although the authors caution the limitations of their approach, they ultimately advocate that their model may provide states with guidelines for how to best distribute tax revenue in regard to the issue of human migration. –Adriane Holter
Marchiori, L., Schumacher, I., 2011. When nature rebels: international migration, climate change, and inequality. Population Economics 24, 569600.

          In an environmental review, the authors remind that while the developed world is responsible for the vast majority of CO2emissions, it is the developed world that will experience 80% of the lived damage of global climate change. These experiences include areas such as the loss of agricultural productivity and water quality, which result in unsustainable living conditions, that oftentimes lead to environmentally motivated migration. Reasons for movement out of an area also may include anticipation of deteriorating and therefore non-sustainable living conditions. The economic model used in the study incorporates concerns of livelihood by presenting a decision calculus that states when a person (referred to as “generations”) considers the benefit of migration to be greater than that of staying at home, then that person will migrate. The firms in the model are stated as operating on the basis of profit maximization in a perfectly competitive market where they have access to international capital mobility.
          The authors present four propositions that result from their analysis, many of which have important policy implications. First, the optimization consideration of firms and the relative situation of the generations, an integrated approach is similar to one of autarky, indicating the economic independence of the firm. Second, endogenous climate change is a large contributor to international migration that effectively diminishes the per capita welfare of both northern and southern regions. Third, increased allocation of funds toward border controls reduces southern access to migration and increases northern control. This relationship has the ability to either exaggerate or lessen current north-south regional inequalities due to environmental improvements and long-run migrant numbers. Finally and similar to the third proposition, an increase in taxes allocated to green technology will potentially decrease migrant numbers, positively impact the environment, and alter the relationship between north-south inequality.
          Based on these propositions, the authors posit that it is advisable for Europe to increase the allotment of tax revenue toward immigration costs than North America. Conversely, North America should invest more tax revenue in green technology than Europe. This inverse economic relationship is due to the fact that production in North America creates substantially larger numbers of CO2 emissions than its European counterpart and therefore may best benefit from new environmental policy. Additionally, North America currently employs harsh restrictions on border control policy. Europe’s comparatively “soft” immigration policy therefore makes new approached recommendable. 

Geographic Disparities and Moral Hazards in the Predicted Impacts of Climate Change on Human Populations

It is well known in the scientific community that climate change will impact humans in several ways depending on their location. However, the myriad of complex decision patterns for human reaction to climate change and the variability of regional impact often limits scientific analysis to qualitative analysis of the consequences of climate change. In response to this trend of study, Samson et al. (2011) studied the relationship between global distributions of human population density and climate to predict future regional climate vulnerabilities. Niche models were used to create this global index of the projected impacts of climate change on human populations by assessing how environmental niches would likely change or move based on shifts in climate. Human population density data were obtained from the Gridded Population of the World and then adjusted to United Nations national population size records, while climate forecast was taken from the WorldClim database. From these data, researchers identified Central America, Central South America, the Arabian Peninsula, Southeast Asia, and much of Africa as the regions whose populations are most vulnerable to the effects of climate change. Notably, these regions are far away from the high-latitude areas where it is estimated that climate change will be the greatest. The research also employed geographically weighted regression models to conceptualize the spatial element of the relationship between climate and humans. – Adriane Holter
Samson, J., Berteaux, D., McGill, B. J., Humphries, M. M., 2011. Geographic Disparities and moral hazards in the predicted impacts of climate change on human populations. Global Ecology and Biogeography published ahead of print February 17, 2011,doi: 10.1111/j.1466-8238.2010.00632.x

          The ecological niche model used in this projection was contrasted with CO2 emissions data to quantitatively discern the concept of a moral hazard in climate change. This moral hazard reflects the relationship of the cause for and the predicted consequences of climate change. Interestingly, researchers found that the human populations that created the largest amount of greenhouse gases on a per capita basis were the least likely to experience the most severe effects of climate change. Researchers also found that the factors that cause regional climate change are correlated with the projected impact of climate change on human populations. Thus, a moral hazard exists on the level that those populations that produce the most green-house gas transmit the harmful byproduct onto other populations.
           The research supports the intuitive theory that areas of the globe that are already dry will increase in dryness and become increasingly vulnerable. One reason for this vulnerability is the difficulty of food production in agricultural and pastoral societies when dryness decreases the amount of arable land. Conversely, cold areas with low population densities will be able to support larger future populations with the impact of climate change. It is extremely likely that climate change will result in new dispersals of human populations throughout the globe; however, we must also ask if reduced population densities in a given location are due to the inability of humans to live there or because they elect to leave. Regardless, these conclusions support the need for climate policy that responds to the predicted needs of those populations that will be most greatly influenced by climate change.  

Migration and Global Climate Change: Future Challenges and Opportunities

The final report on migration and global environmental change by the Government Office of Science London, stems stems from the premise that human migration encompasses drivers and consequences in such a diverse field of areas that these areas should unite to find a common policy recommendation for the issue. The five main drivers identified by the report illustrate the range of disciplinary fields involved in the subject of human migration: economic, social, political, demographic, and environmental; however, the authors of the report do distinguish between the conditional levels of support each category has in varied scenarios. On average, economic concerns have the greatest relative impact on human migration. Although often perceived as the most dominant, social factors usually come second to economic reasons for migration. In regard to environmental impact, deserts and dry lands are noted as exceptional regions where migration is a substantial concern for the sustainability of the livelihood and quality of life of human populations. – Adriane Holter
Foresight: Migration and Global Environmental Change, 2011. Final Project Report. The Government Office for Science, London.

          A desert dryland is defined as having limited soil moisture with low rainfall and high evaporation rates. These areas are home to 2 billion people, totaling 40% of the earth’s surface. Drylands are also subject to land degradation due to harsh environmental conditions and human activities such as agriculture. As a result of land degradation, the already limited natural resources in these arid regions diminish to levels where humans often are unable to sustain a comfortable existence and thus decide to migrate. These regions are also highly susceptible to sustained  periods of drought, further imperiling human livelihoods. The researchers anticipate, through the study of temperature change and rainfall in Southern Africa, West Africa, North Africa, and Mexico, that since 1970 these regions have experienced a strong, steady increase in the number of people that have relocated. In comparison to the numbers leaving, a comparatively miniscule number of people are immigrating into or returning to these regions.
          Overall, the researchers of the study seem to frame migration as a traditional social tool that has been adapted as a solution for the dilemmas posed to humans in rapidly deteriorating environments. Furthermore, many of the traditional drivers for human movement (e.g. economic and social) are the cause of pressures resulting from environmental conditions. Therefore, it is fair to state that ecological reasons account for a large majority of the drivers that cause human migration; however, the type of migration that may occur in any given scenario is subject to several factors. This study identifies two main types of migration: rural-to-rural migration aimed at diversifying social and economic opportunities and longer-distance migration. The former often lowers the likelihood of the latter, which requires economic capital to undertake. Perception is also identified as a crucial element for movement. If a person perceives a situation to be more dire than it truly is, they will respond as if the situation were indeed that dire. Thus, real and perceived impacts of climate change have the potential to create a lived impact on human demographics. The way in which these different modes and reasons for migration unfold is largely determined by the unique political and social structures within which they occur.
          Additionally, the paper highlights the dilemma of ‘trapped’ populations that experience extreme impacts from climate change and are unable to plan migration due to these circumstances. The researchers recommend that due to its vulnerability, this group of people should be given priority for relief from policy makers. If policy responses are not made to correct for the dilemmas of ‘trapped’ populations and all those impacted by climate change, the researchers suggest that marginalized groups will be highly susceptible to extreme environmental events, conflict is likely to occur, and management will result in political upheaval and displacement. Well-researched and multi-disciplinary educated policy formulas are the best way to combat these projections of the future of climate change on human populations.

Migration and Global Environmental Change

This report uses a livelihood approach to understanding migration patterns in Burkina Faso, Ghana, Ecuador, and Nepal. The livelihood approach shares modeling similarities with the New Economics of Labour Migration approach and, as such, includes natural resources as a fundamental source of analysis for movement and mobility. Due to the incomplete nature of scientific information on the evolving state of global environmental change, the author promotes the understanding that an understanding of human movement off of environmental reasons is too subject to error to provide accuracy. Thus, established patterns of contextual, qualitative reasons for human migration are the most accurate for future predictions and adaptive scenarios. –Adriane Holter
Tacoli, C., 2011. Migration and Global Environmental Change. International Institute for Environment and Development: UK Government’s Foresight Project.
It is interesting to note the argument and source of the paper. Although the author notes that the views in the project do not express any standard governmental opinion, the thrust of the argument focuses on policy issues in a way that isolates environmental factors from such a label. As such, the effects of environmental change are made to sound uncontrollable and therefore free from regulation. For example, refers to the scientific community’s inability to attain baseline data for migration flows as one reason why it is questionable to use environmental analysis to promote the sole rationale for induced human migration. The uncertainty of environmental change in political debates may be one cause for such a characterization of its role in human migration as presented by a governmental source.
The core of the author’s argument rests on the premise that human migration must be understood in full context in order to develop a competent coping mechanism to address the associated issues. To achieve substantive analysis, the author uses a non-static livelihood approach, meaning that new data and evolving living situations are considered and implemented into the report. Real world scenarios are then taken from previous studies in the four selected regions with the Burkina Faso and Nepal cases also look at non-migrants, while Ghana and Ecuador primarily consider migrant populations.
The main point of analysis in the study is derived from the luivlihood issues that surround any environmental reasons for migration discovered by any of the cited empirical studies. Human capital, defined as education and skills, has a large impact on movement, especially in rural-urban movement. Similar in importance, sustainability. At the point where living conditions become unsustainable in a region, those persons who are able to migrate are better off than those who are unable and must then remain in unfavorable living conditions. It is thus necessary that non-migrants existing in geographic zones where large amounts of migration have occurred be treated as a vulnerable population. Ultimately, the author states that migration and human movement is on an increasing upswing from current rates with environmental change as a driving cause.
The author concludes by offering the recommendation that policy makers become aware of and positively attempt to implement programs that address the increasingly prevalent role of human movement in societies. These understandings should also be coupled with the knowledge that economic considerations also greatly impact who moves and to where. On the national level, some countries, such as the Nepal case study, have used the situation of human migration to create a national strategy of economic development. Ways to achieve the link between human movement, policy, and economic sustainability include education, access to markets, land holdings, and access to resources and labor. In order to avoid the impact of extreme migration patterns due to environmental disasters, policies adopted to appropriately address such a situation should also be developed.

Abrupt Holocene climate change as an important factor for human migration in West Greenland

Temperature fluctuations in West Greenland are known to have impacted human movement and migration during the Holocene period. However, due to the myriad of social, political, and economic reasons that humans move from land it is difficult to pinpoint how much temperature impacted change in behavior. D’Andrea, Huang, Fritz, and Anderson et al. (2011) tested the relationship between temperature and four groups that inhabited West Greenland during the Holocene period through the comparative study of sediment samples from two lakes. This method allowed researchers to compare the past state of temperature variability in West Greenland with historical records of human populations in the region. The study found that fluctuations in temperature did have a positive correlation with population shifts out of the West Greenland area. Importantly, this research helps provide examples of how climate change has shaped geological epochs of human history.  – Adriane Holter
          D’Andrea, William J., Huang, Yungsong, Fritz, Sherilyn C., Anderson, John N., 2011. Abrupt Holocene climate change as an important factor for human migration in West Greenland. Proceedings of the National Academy of Sciences of the United States of America, 108: 9765-9769.

          During the Holocene period, four groups of people lived in the West Greenland area: the Saqqaq (4,500 y B.P.), the Dorset (2,800-2,200 y B.P.), the Norse (650 y B.P.), and the Thule who still remain in the area to present. Throughout the Holocene period, the civilization of these four groups was substantially impacted by temperature change. For instance, access to resources and tools for acquiring such resources was greatly influenced by environmental conditions. Thus, an abrupt change in temperature had the potential to alter the lives of a population to a large enough degree that they left an area. When compared to human migration in West Greenland, it is highly likely that Holocene temperature variability was a dominant force in population shifts.
          During the time that the Saqqaq inhabited West Greenland, the region experienced an interval of warmth that then shifted into a transient period of warmth and cooling between the years 4,100 and 3,400 B.P. The authors hypothesize that an abrupt cooling of the region that occurred in 3,400 B.P. began to push the Saqqaq out of the Sisimiut region; however, it was not until further decrease in temperature in 2,800 B.P. that the group left the area completely. Thus, the magnitude of the temperature shift is an essential element of how humans experience climate change; rate of change alone does not determine human impact.
          Unlike the Saqqaq, archaeological evidence from the Dorset population suggests that the group was better adapted to handle fluctuations in temperature. For instance, remnants of tools for sea-ice hunting suggest that the Dorset were well suited to cold weather conditions. Due to their living strategies, it is more difficult to determine why the Dorset abandoned the region in 2,200 B.P instead of other periods of significant temperature change that occurred during the time they inhabited West Greenland. The unclear reasons for the migration of the Dorset remind us that theories of climate change produce only a partial explanation of human movement. Nevertheless, temperature shifts can partially explain why certain groups move into an area to begin with. The warming of West Greenland experienced from ca. 1,000 to 850 B.P. (roughly middle of the 14thcentury) is one probable reason that the Norse migrated to the region. Once again, lifestyle factors impacted how a population was impacted by climate change. A sedentary farming population, the Norse were less able to response to temperature shifts and were therefore greatly impacted by the period of increased cooling from 850 until 630 B.P. when they abandoned West Greenland leaving the area free for the Thule to settle to the present day.
          In order to establish these relationships between temperature and population in West Greenland, the researchers studied sediment cores from two lakes (Braya Sø and Lake E) that were 10 kilometers apart. By examining the alkonene levels in the sediment cores, the authors were able to reconstruct sea-level temperatures during thousands of years. This research was strengthened by the fact that previous studies have shown air temperature has a strong impact on sea-level temperature in West Greenland. The study indicates that temperature might have varied as much as 5.5 ° Celsius in the Kangerlussuaq region over the past 5,600 years. Interestingly, the authors found that the temperature patterns in West Greenland were anti-correlated with other areas in the North Atlantic such as southwest Ireland. 

Migration path annotation: cross-continental study of migration-flight conditions

The movements of animals are an important indicator of how they interact with and use land resources in sustainable ways. Thus, the study of how migratory patterns change due to external environmental influences may provide an indication of a species’ ability to survive in the event of rapid climate change. Mandel et al. (2008) created a study that tested the flight patterns of three geographically separate populations of turkey vultures to ascertain which topographical and weather variables created a shift in movement. For purposes of the study, movement was defined as the straight-line distance between two points and navigation was recorded based on the hourly deviations a bird’s flight pattern relative to their seven prior recorded hours. The birds were tagged and monitored with a GPS network that fed into a gridded data set that allowed researchers to observe the birds’ movements. From these they could visualize predictable error rates and global patterns. The researchers found that the movement of east and west coast turkey vultures was influenced by the topography of the land that they flew over. For all three populations of birds, horizontal wind speed was the largest factor in the deviation of migratory paths; however, the effect on each population differed. West coast birds had an increased deviation in high winds, but their flight path was not directly impacted by the direction of the wind. East coast birds flew in the straightest path when the wind strength was at either the low or high end. Conversely, whereas coastal birds responded to both slope and thermal soaring, interior birds only used thermal soaring. – Adriane Holter
Mandel, James T., Bohrer, Gil, Winkler, David W., Barber, David R., Houston, C. Stuart, Bildstein, Keith T. Migration path annotation: cross-continental study of migration-flight response to environmental conditions. Ecological Society of America, Vol 21. Issue 6.

          Turkey vultures direct their flight by identifying a thermal zone and then soaring through that zone on an air current. This method of flight is crucial for the species to use the least possible amount of energy. In order to determine how turkey vulture migration might be impacted by climate change, the authors of the paper studied topography and weather variables alongside the flight patterns of turkey vultures. The conclusion of the research determined that these factors do change the way that turkey vultures migrate.
          The birds in the two coastal locations, southern California and eastern Pennsylvania, experienced higher levels of turbulence kinetic energy (TKE) in the air as they flew through mountain ranges. TKE refers to the amount of friction in the air current surrounding the birds. A higher level of TKE signifies more friction in the air, which negatively impacts the birds’ ability to coast in the air with the minimum possible energy output. In response to the TKE levels around the mountains, the birds flew in slope patterns that reflected the shape of the mountain ranges to provide protection from wind. Internal continental birds, from central Saskatchewan, did not encounter much TKE because they flew through an area that was flat and did not need to change their flight patterns to avoid it. In addition, internal continental birds did not respond to thermal patterns. This research thus implies that changes caused to topography and weather due to climate change has the potential to alter the way that regional populations of a bird species move and interact wit their surroundings.