Indigenous ecological calendars and seasonal vector-borne diseases in the Colombian Amazon: an intercultural and interdisciplinary approach

ABSTRACT Traditional ecological knowledge of indigenous groups in the southeastern Colombian Amazon coincides in identifying the two main hydrological transition periods (wet-dry: August-November; dry-wet: March-April) as those with greater susceptibility to disease in humans. Here we analyze the association between indigenous knowledge about these two periods and the incidence of two vector-borne diseases: malaria and dengue. We researched seven “ecological calendars” from three regions in the Colombian Amazon, malaria and dengue cases reported from 2007 to 2019 by the Colombian National Institute of Health, and daily temperature and precipitation data from eight meteorological stations in the region from 1990-2019 (a climatological normal). Malaria and dengue follow a seasonal pattern: malaria has a peak from August to November, corresponding with the wet-dry transition (the “season of the worms” in the indigenous calendars), and dengue has a peak in March and April, coinciding with the dry-wet transition. Previous studies have shown a positive correlation between rainfall and dengue and a negative correlation between rainfall and malaria. However, as the indigenous ecological knowledge codified in the calendars suggests, disease prediction cannot be reduced to a linear correlation with a single environmental variable. Our data show that two major aspects of the indigenous calendars (the time of friaje as a critical marker of the year and the hydrological transition periods as periods of greater susceptibility to diseases) are supported by meteorological data and by the available information about the incidence of malaria and dengue.


INTRODUCTION
Amazonian indigenous people are keen observers of natural rhythms and have accumulated extensive and sophisticated knowledge of seasonal cycles (Echeverri 2009).This knowledge has been recorded by researchers and more recently by indigenous people themselves, with the name of "ecological calendars" (van der Hammen et al. 2012;Rodríguez and van der Hammen 2012), "traditional calendarmaps" (Velasco Álvarez 2021), or "eco-health calendars" (SantoDomingo et al. 2016).These ecological calendars are used to claim and negotiate indigenous ways of life distinct from the development policies promoted by state agents (Cayón 2012;Estrada Añokazi 2018) or as an approach seeking to integrate local knowledge in the context of vectorborne disease prevention, from an eco-health framework (SantoDomingo et al. 2016).
Three of us (Cárdenas Carrillo, Venegas and De Vengoechea) carried out ethnographic research in the Middle Caquetá region in the southeastern Colombian Amazon in 2018-2019, resulting in the compilation of the ecological calendar of the Féenemɨna'a ethnic group (formerly known as Muinane).We also collected information from calendars of six other indigenous groups in the regions of the Middle Caquetá, Igaraparaná and Mirití-Paraná (Franky 2004;Makuritofe and Castro 2008;Andoque and Castro 2012;Henao and Farekatde (2013); Estrada Añokazi 2018; García 2018;Guhl 2018).They all coincide in relating hydrological cycles with a variety of ecological phenomena such as the phenology of wild and cultivated plant species, the reproduction of fish and terrestrial vertebrates, and insect diversity.These calendars mark "seasons" that have an incidence in regulating the annual horticultural cycle and the greater or lesser susceptibility to diseases in human beings.Although the number and name of seasons differ among different indigenous calendars, all of them identify the hydrological transition periods from the wet to the dry, and from the dry to the wet seasons in the Colombian Amazon as those with greater susceptibility to disease in human beings.The most marked event in all these calendars is the meteorological phenomenon regionally known as friaje, caused by cold air currents that have their origin in the Antarctic Ocean and affect part of the South American continent (Marengo 1984).
Here we analyze the association between indigenous knowledge about these two hydrological transition periods, as contained in their calendars, and the epidemiological information on the incidence of vector-borne diseases in the Colombian Amazon.Even though the major health ailments in this region are gastrointestinal, respiratory, and dermatological diseases (Suárez-Mutis et al. 2010), these are rarely reported in the Colombian National Public Health Surveillance System (SIVIGILA).Therefore, we opted to use data on occurrence of malaria and dengue recorded by SIVIGILA.Malaria was introduced in South America in colonial times (Carter 2003;Yalcindag et al. 2012) and has been prevalent in the Amazon region for centuries.Dengue was introduced in the Americas in the XVII century (Wilson and Chen 2002;Brathwaite Dick et al. 2012), but the first recorded outbreaks in western Amazonia are from the 1990s (Phillips et al. 1992).Precisely for being introduced diseases, malaria and dengue are far better reported than gastrointestinal or respiratory diseases.
Both malaria and dengue are widespread throughout the tropical and subtropical regions.Malaria is caused by parasites of the genus Plasmodium and is transmitted by mosquitoes of the Anopheles genus in the Americas (Wilson and Chen 2002;Carter 2003;Yalcidang et al. 2012;Achee et al. 2015).There were 229 million estimated cases and about 400,000 deaths worldwide in 2019 (WHO 2021).Brazil, Colombia, and Venezuela account for more than 86% of cases in South America, with approximately 90% of the patients reported from the Amazon region (WHO 2020).Malaria is one of the morbidities with the best records in SIVIGILA, even though the Amazon region shows high levels of disease underreporting (Gutiérrez 1982;Minsalud 2013;Chaparro et al. 2012).Dengue is caused by a virus of the Flaviviridae family and its main vectors are the mosquitoes Aedes aegypti (L.) and Aedes albopictus (Skuse) (Achee et al. 2015).More than 2.5 billion people are at risk of infection, and more than 160 countries have endemic transmission (WHO 2009).
The indigenous calendars do not refer to malaria and dengue by their names; instead, they mention their symptoms such as fever, chills, headache, diarrhea, vomiting, and body aches.We analyzed the relationship between the two hydrological transition periods, as they are signaled in the indigenous calendars from the Middle Caquetá, Igaraparaná, and Mirití Paraná regions, with the incidence of malaria and dengue, as reported in SIVIGILA.Data are analyzed from an interdisciplinary perspective, combining natural and social sciences.

Ecological calendars
We researched seven ecological calendars: three from the Middle Caquetá region in Colombia: Nɨpodɨmakɨ (Makuritofe and Castro 2008);Féenemɨna'a (Cárdenas Carrillo,Venegas and De Vengoechea, unpubl. data), and Andoque (Andoque and Castro 2012;Estrada Añokazi 2018); two Murui Mɨnɨka calendars from the Igaraparaná region (Henao and Farekatde (2013); García 2018); and two calendars from the Mirití-Paraná river region: Yukuna (Guhl 2018) and Tanimuka (Franky 2004). 1 Makuritofe and Castro (2008) is a booklet ACTA AMAZONICA written by a Nɨpodɨmakɨ elder with the help of a younger indigenous leader, profusely illustrated, accompanied by a narrative text.Henao and Farekatde (2013) is a book chapter about the notion of "climate", authored by an indigenous elder and an anthropologist, including a table and text about the ecological calendar.The other sources contain information about the indigenous calendars in tabular or narrative form as part of scholarly dissertations in anthropology.These three regions encompass a large area of about 5 million ha (Figure 1).From the seven calendars, we synthesized the biological, climatic, cultural, and disease information and correlated them with the months of the Gregorian calendar.

Meteorological data
We obtained the meteorological data for the region from the Colombian Institute of Hydrology, Meteorology, and Environmental Studies (IDEAM 2021).We downloaded the daily precipitation data from six meteorological stations (Aguazul, Angosturas, Araracuara, Cuemaní, Monochoa, and Santa Isabel), and daily maximum and minimum temperatures from three meteorological stations (Araracuara, Tres Esquinas, and La Chorrera) for the 1990-2019 period, i.e., a 30-year climatological standard normal, which is defined as the average of climatological data computed for a period of 30 years (Trewin 2007) (Figure 1; Table 1).From the daily values, we calculated monthly accumulated precipitation and average monthly minimum and maximum temperature.The standard deviation for each month was calculated from the pluriannual averages of each station.
The occurrence of friaje periods was assessed by calculating the number of cold outlier days per month.A cold outlier is a temperature datum below Q1-1.5*(Q3-Q1),where Q1 is the middle value between the lowest datum and the median (Q2) of the data set and Q3 is the middle value between the median and the highest datum of the 30-year temperature data set.In addition to the three meteorological stations in the immediate study region (Araracuara, Tres Esquinas, and La Chorrera), we also used the data from the meteorological station of Leticia (Colombia) to determine the friaje periods, as the phenomenon occurs on the continental scale (Ricarte et al. 2015).

Malaria and dengue cases
We retrieved information about malaria and dengue cases reported from 2007 to 2019 from the routine surveillance statistics of the National Public Health Surveillance System

AMAZONICA
of Colombia, which has health records available online since 2007 (SIVIGILA 2020).We selected the health report from five localities: the municipality of Solano in the department of Caquetá (west of the study area), and four municipalities in the department of Amazonas (Puerto Santander, in the middle Caquetá region, Mirití and La Pedrera, in the Mirití-Paraná region, and La Chorrera, in the south of the study area (Table 1).These municipalities are the territorial units corresponding to the three regions from where the ecological calendars come from and related to the meteorological stations from which climatic data were retrieved (Figure 1; Table 1).
We used Spearman's nonparametric correlation in the software Past v4.3 (Hammer et al. 2021) to determine the association between monthly average precipitation and the monthly cumulative number of malaria cases from all localities.

Indigenous calendars
The indigenous calendars we consulted identify the time of friaje as a central event in the annual calendar.Indigenous groups mark this event, which lasts only a few days, as the beginning of the annual ecological cycle.This annual cycle can be divided into four major periods, defined by the hydrological cycle: 1) the wet-dry transition, immediately after the friaje, between August and November; 2) the dry season, between December and February; 3) the dry-wet transition, between March and April, and 4) the wet season, between May and July (Figure 2a), corresponding to the Amazonian hydrological cycle of the climatic northern hemisphere (Gutiérrez 1982).The different indigenous ecological calendars give names to the seasons according to major ecological variables (e.g., hydrological conditions, phenology of plant species, fauna, etc.) (Table 2).

Wet-dry transition: season of the worms
The wet-dry transition period, which lasts up to four months, is characterized by a succession of "false" dry periods interspersed with periods of rain; they are called "false" because   S1).Data from IDEAM (2021).B -Monthly average of daily maximum and minimum temperatures from meteorological stations in La Chorrera (Amazonas), Tres Esquinas and Araracuara (Caquetá) in the Colombian Amazon, from January 1990 to December 2019 (raw data available in Supplementary Material, Table S2).Data from IDEAM (2021).C -Monthly cumulative cases of malaria and dengue reported in the localities of La Chorrera, La Pedrera, Mirití-Paraná, Puerto Santander and Solano in the Colombian Amazon, in 2007-2019 (raw data available in Supplementary Material, Tables S3 and S4).Data from SIVIGILA (2020).
ACTA AMAZONICA their duration is shorter than the main, more extended dry season (García 2018).The first false dry season is called "season of the worms'', among the indigenous groups of the People of the Center 2 (Makuritofe and Castro 2008; Andoque and Castro 2012), or "season of the cicadas'' for the groups living in the Mirití-Paraná River basin (Yukuna, Matapí, Letuama, and Tanimuka) (Franky 2004;Guhl 2018).
The season of the worms 3 (or cicadas) is characterized by a higher incidence of physical and spiritual diseases, the latter 2 The People of the Center include the Murui (also called "Witoto", which comprises the Nɨpodɨmakɨ and the Murui-Mɨnɨka), Féenemɨna'a (also called Muinane), Andoque, and Nonuya ethnic groups living in the Colombian Middle Caquetá region.
3 The different calendars describe the reproductive phases of butterflies in detail.The Andoque consider worms and butterflies as the same animal, as Gómez (2011) mentions when referring to the origin of worms and butterflies: "the worms began to eat the leaves, they pupate back and finally burst into butterflies." Esteban Ortiz, a Féenemɨna'a man, says: "There are clouds of butterflies flying in the fallows, and fifteen days later the trees are all eaten.People walk through the forest, and that is like excrement raining from the branches'' (Cárdenas Carrillo, Venegas and De Vengoechea, unpubl. data).Indigenous people consider worms as a potential danger due to their ability to cause itchiness, sting, poison, or cause allergies, and because their smell is sometimes unpleasant and is directly associated with disease.
manifested in psychic or moral disorders such as laziness, rage, envy, jealousy, madness, and so forth (García 2016).As these diseases affect not only individuals but also the whole group, some of the actions carried out by People of the Center groups consist of ritual dances and dialogues, seeking to neutralize and avert the agents that cause them (García 2016).
The different indigenous calendars agree that this time is over when the sun shines, and the caimo fruits mature, an event that gives its name to the dry season of the caimo fruits, preceding the false dry season of inga.Makuritofe and Castro (2008) state that once caimo fruits turn yellow, the owner of this fruit, the jipikoreiño bird, sings: pi'chɨɨ, pi'chɨɨ, pi'chɨɨ, ACTA AMAZONICA making the first fruits full of worms, while those that ripen at the end of the season are healthy.
In the transition period, diseases related to viruses, bacteria, protozoa, or, in general, microscopic organisms, occur, associated with the contamination accumulated during the time of friaje (immediately before the season of the worms), as stated by Makuritofe and Castro (2008): "During the friaje (ro'yitɨmuy) pests or diseases are released on mother earth, it is the garbage or invisible waste that comes into the air, one does not get sick at the moment, but later at another time." There are caterpillars of Lepidoptera (butterflies and moths) associated with the season of the worms as well as other taxonomic groups with vermiform organisms.During this period, mammals and fish are infected with vermiform organisms (Makuritofe and Castro 2008).That is why this season is also called the time of fish epidemy, which manifests as fever, vomiting, diarrhea, and stomach parasites.These gastrointestinal diseases could be related to fish or mammals infected with nematodes or flatworms, also with waterborne pathogens.
The second sub-period (October-November) of the wetdry transition is distinguished by a succession of false dry seasons, interspersed with periods of rain.It corresponds, in all indigenous groups, with the ripening of fruits of different species: the beginning of flowering of the peach palm (Bactris gasipaes), the emaio tree (not identified), the forest grape (P.cecropiifolia), and inga (I.edulis).

Dry season
The dry season (December-February) is mainly marked by the ripening of the fruits of the yellow umarí tree (Poraqueiba sericea) and most importantly, the ripening of the peach palm (B.gasipaes).In this season, the river reaches its lowest levels.At the beginning of the dry season, new horticultural plots are slashed, which will be burnt at the end of this season.The burning of the horticultural plots is associated with a higher prevalence of respiratory symptoms and allergies.Within the nosology of the People of the Center, fire is considered both a manifestation of disease and as a purifying element to treat it.Arachnids, worms, butterflies, wasps, and different insects associated with the appearance of itching on the skin are struck down with fire.

Dry-wet transition
The second transition period is in March and April, immediately after the dry season.It is marked by the ripening of the fruits of the cucuy tree (Macoubea guianensis) and the green umarí tree (another variety of P. sericea).For the Yukuna and Tanimuka, this is the time to celebrate the yuruparí or men's initiation ritual.It is also marked as a time of illness.This transition period corresponds to the beginning of the wet season; the rains increase, and the first flood of the year occurs (Makuritofe and Castro 2008), which lasts until the end of June.
The rainfall drains flowers, dead branches, and other debris from the earth that contribute to the accumulation of litter and tree debris while strengthening the fish.Several health problems are manifested during this time such as flu, headache, skin diseases, fungi related diseases, and diarrhea (Makuritofe and Castro 2008).The floods restrict passage on the mainland and bring animals closer to where human beings settle.
During this time, fishing is reduced because, with the increase in the river's water level, the fish disperse into creeks, streams, and flooded areas.This is the time of reproduction for terrestrial fauna.Large mammals, such as tapir, jaguar, deer, anteater, and birds, such as macaws and parrots, begin to be born approximately between April and May.Indigenous peoples believe that animals in this season are filled with worms and that, therefore, humans must prepare them properly before consumption to prevent diseases.Similarly, there is an increase in mosquitoes, since insects lay eggs in stagnant waters in April.

Wet Season
During the wet season (May-July), as precipitation increases, several wild plants fruitify, river levels rise, and it is the breeding season for fish.During this season, several milder friaje events can occur (named "false" in the calendars) that conclude with the major friaje, named after the miriti palm (Mauritia flexuosa) between July and August.

Friaje
The time of friaje coincides with the southern hemisphere's winter season (July-August).During the friaje season, the feeling of cold increases and moderate rainfall is accompanied by gusts of wind.These winds cause large drops in temperature in short and irregular periods that go from May to September and are more noticeable in June and July.According to the temperature data for the three stations with temperature data (Araracuara, Tres Esquinas, and La Chorrera), plus Leticia, for the period 1990-2019, there were 111 cold outlier days in July, 47 in August, 28 in June, 11 in September, nine in May, eight in February, six in April, three in March, two in October, and two in November.This corresponds with the marking of several friaje events of variable intensity in the indigenous calendars.The friaje announces the arrival of the wet-dry transition period and marks the end and new beginning of the ecological annual cycle, corresponding with the months of July and August (Table 2).
The friaje season is very important in ecological and cosmological terms.In mythical history, it marks a turning point between a time when diseases, evil and plagues affected humanity and crops, and a time when the cold weather harmonizes the atmosphere, animals are differentiated from ACTA AMAZONICA humanity, and the celebration of ritual festivals begins.The friaje is a time of purification of nature and humanity.Part of the ecological management carried out by the indigenous connoisseurs is to request that the friaje arrives every year, as it is an indicator of good ecological functioning.

Temperature and precipitation data
Precipitation data was available for 87% of the 10,957 days of the 1990-2019 period (Supplementary Material, Table S1).Average monthly accumulated rainfall across stations showed a unimodal pattern, with a peak in May (the beginning of the wet season in the indigenous calendars) and lowest values in January (a month before the dry-wet transition) (Figure 2a).
Temperature data was available for 94% of the 10,957 days of the 1990-2019 period (Supplementary Material, Table S2).Average minimum and maximum daily temperatures were 21.9 and 31.7 °C in La Chorrera; 20.7 and 31.0 °C in Tres Esquinas; and 22.3 and 31.3 °C in Araracuara.The average minimum and maximum for the coldest month (July) were 21.1 ± 1.5 °C and 30.5 ± 1.8 °C, respectively (Figure 2b; Supplementary Material, Table S2).The overall minimum daily temperature was 12.8 °C, and the maximum temperature was 39.4 °C.The lowest average temperatures in Tres Esquinas and Araracuara were recorded in July, and in La Chorrera in August (Supplementary Material, Table S2), coinciding with the friaje events, as stated in the indigenous calendars (Table 2).

Cases of malaria and dengue
SIVIGILA recorded 8,316 cases of malaria in the period 2007-2019 for the five surveyed localities (Table 3).La Pedrera presented the largest number of cases, with more than 1,000 accumulated cases during September, October, and November.The records for malaria were assumed to be relatively complete because, to have access to the treatment, people need to go to a health center to get tested.However, it is also likely that many cases go unreported, mainly from communities more distant from health centers.Puerto Santander has no cases reported in 2007, 2008, 2011, and 2012;Solano has no cases reported in 2008Solano has no cases reported in , 2013Solano has no cases reported in , and 2015; and Pedrera has no cases reported in weeks 51 and 52 of 2018 (Table 3; Supplementary Material, Table S3).We found a negative correlation between monthly average precipitation and the cumulative number of malaria cases from all localies (r s = -0.65,P = 0.02).
Dengue was found to be grossly underreported in the Colombian Amazon (Table 4).In 2010 there were only four registered cases in the four surveyed localities (Supplementary Material, Table S4), although during that year, the overall number of dengue cases in Colombia was 146,670, with 217 deaths caused by severe dengue (Castrillón et al. 2015).Raw dengue data from SIVIGILA shows that, in the surveyed period, prominent peaks of dengue occurred in Colombia in 2010, 2013, 2014, 2016and 2019(SIVIGILA 2020)).These countrywide peaks are reflected in 2013 and 2014 in the four surveyed localities (Supplementary Material, Table S4), but not in the other peak years, suggesting underrepresentation.
The available data indicate that dengue and malaria are seasonal diseases, with malaria peaks from September to November, during the wet-dry transition, while dengue peaks in March, at the beginning of the dry-wet transition (Figure 2a,c).

Locality
Monthly ACTA AMAZONICA physical, biological, and ecological variables and relates them with occurrence of human and non-human health conditions.From all the information presented, we discuss the most remarkable interaction points between the evaluated meteorological and health data and the chronology of the indigenous calendars.
Even though the variation in average temperatures along the year is relatively slight compared to higher latitudinal climatic regions, all the indigenous calendars we consulted identify the time of friaje as a key event, which defines the "beginning" of the year.The friaje takes place in July and August, and its time of occurrence and degree of intensity are indicative of the overall health of animals, plants, ecosystems, and human beings.As stated by Echeverri (2009, 19), "For indigenous peoples, the friaje is the time of the 'menstruation' of the earth."As the duration of the friaje is just a few days (less than a week), its effect normally does not reflect on monthly temperature averages.Nonetheless, data of maximum and minimum temperatures recorded for the region in 30 years indicate that July and August have the lowest average temperature and the largest number of cold outlier days.
The effects of these brief periods of cold temperatures on animal reproduction, plant phenology, and human health are difficult to fathom.Although it has been reported that daily variations in temperature can influence the transmission process of malaria (Paaijmans et. al. 2010), we do not intend to establish any relationship between temperature and malaria or dengue.We limit ourselves to pointing out the coincidence between the rise in malaria cases (but not dengue cases) and this important season in the indigenous calendars.
Indigenous ecological calendars divide the year (beginning in August) into numerous "seasons", but we can group them into four major periods: the wet season, the dry season, and two transition periods.All calendars adamantly state that the transition periods are those when susceptibility to diseases in human beings increases.Although malaria or dengue are never named in indigenous calendars, and the array of ailments that may affect indigenous populations obviously is more extensive than malaria and dengue, these two diseases do affect indigenous communities in the Colombian Amazon (Méndez et al. 2006;Recht et al. 2017;Poveda 2020).Even though there may be an important degree of underreporting for dengue (and to a lesser degree for malaria), the data available for 2007-2019 shows that these two diseases have a clear seasonal pattern.The peak of malaria corresponds with the wet-dry transition, or the "season of the worms" in indigenous calendars, and the peak of dengue coincides with the dry-wet transition.Apart from malaria and dengue, the indigenous calendars refer to the occurrence of respiratory, gastrointestinal, and dermatological diseases.
Studies in other areas have determined a significant positive correlation between rainfall and the occurrence of dengue (Hoek et al. 1997;Hii et al. 2012;Silva et al. 2016).This is coherent with the coincidence of the dengue peak in the dry-wet transition in our study area, but does not explain why dengue cases tend to diminish during the wet season, which may be related to substantial underreporting.For malaria, a negative correlation with rainfall has been reported (Hoek et al. 1997;Mason et al. 2005;Briët et al. 2008;Bomblies 2011), which was confirmed by our data, which also shows a significant negative correlation between precipitation and reports of malaria.
Our data show that two structural postulates of the indigenous ecological calendars are supported by meteorological and epidemiological data: the time of friaje as a key marker of the year and the two hydrological transition periods as epochs of greater susceptibility to diseases.This is indicative of the potential richness of this traditional ecological knowledge, which so far has been neglected or regarded as a mere ethnographic curiosity.

CONCLUSIONS
Our study shows a close relationship between the observations recorded by indigenous experts in their ecological calendars and meteorological data and the seasonal occurrence pattern of two vector-borne diseases.Beyond simple coincidences, these similarities signal the convergence of two languages: that of the scientific method and the interpretation of the world based on empirical observation of the indigenous people and their way of life that responds appropriately to the natural rhythms of their environment.Accurate and complete epidemiological information and the potential of indigenous ecological knowledge, as we have shown here, can be a powerful tool for an interdisciplinary and intercultural approach to healthcare of the populations in this region.

ACKNOWLEDGMENTS
The authors want to acknowledge the indigenous communities of the Middle Caquetá, Mirití-Parana and Igaraparaná regions in the Colombian Amazon, particularly the Féenemɨna'a and Nɨpodɨmakɨ, who have shared their knowledge with us, and whom we recognize as valid interlocutors in the construction of intercultural knowledge to protect people's health and well-being.This research was funded by Universidad Nacional de Colombia, through the projects "Memoria oral y prácticas propias de uso y fortalecimiento de la lengua muinane en la Amazonia colombiana" (led by professor Consuelo de Vengoechea) and "Fortalecimiento del conocimiento y cuidado de la Selva y la Chagra desde la cultura y lengua de pobladores del medio Amazonas colombiano" (led by professor Nubia E. Matta, Hermes 47223).

SUPPLEMENTARY MATERIAL (only available in the electronic version)
Jiménez et al.Indigenous ecological calendars and seasonal vector-borne diseases in the Colombian Amazon: an intercultural and interdisciplinary approach Table S1.Monthly precipitation data (in mm) for the Angosturas, Aguazul, Araracuara, Cuemaní, Monochoa and Santa Isabel meteorological stations in the Colombian Amazon, from 1 January 1990 through 31 December 2019.Empty cells: no data available.Values in italics did not have measured rainfall for all days in the month and had the monthly precipitation estimated using simple arithmetic average of rainfall in other stations with complete data (Sattari et al 2016).Source: compiled from raw daily data in IDEAM ( 2021).CUE = Cuemani; ANG = Angosturas; MON = Monochoa; ARA = Araracuara; AGU = Aguazul; SAN = Santa Isabel.

Figure 1 .
Figure 1.Map of the Colombian Amazon showing the three regions from where indigenous ecological calendars were obtained, health report localities and meteorological stations.

Figure 2 .
Figure 2. A -Monthly average precipitation from six meteorological stations in the Colombian Amazon, from January 1990 to December 2019.The bars indicate the standard deviations from the pluriannual averages (raw data in Supplementary Material, TableS1).Data from IDEAM (2021).B -Monthly average of daily maximum and minimum temperatures from meteorological stations in La Chorrera (Amazonas), Tres Esquinas and Araracuara (Caquetá) in the Colombian Amazon, from January 1990 to December 2019 (raw data available in Supplementary Material, TableS2).Data from IDEAM (2021).C -Monthly cumulative cases of malaria and dengue reported in the localities of La Chorrera, La Pedrera, Mirití-Paraná, Puerto Santander and Solano in the Colombian Amazon, in 2007-2019 (raw data available in Supplementary Material, TablesS3 and S4).Data from SIVIGILA (2020).

Table 1 .
Correspondence among regions, indigenous groups, and localities from which malaria and dengue occurrence data and meteorological data were obtained for the analysis of indigenous ecological calendars in the Colombian Amazon.

Table 2 .
Synthesis of indigenous ecological calendars from the middle Caquetá, Igarapaná, and Miriti regions, southeastern Colombian Amazon.

Table S2 .
Monthly average maximum and minimum temperatures in Celsius degrees from La Chorrera (Amazonas), Araracuara (Amazonas) and Tres Esquinas (Caquetá) in the Colombian Amazon, from January 1990 to December 2019.Source: compiled from raw daily data in IDEAM (2021).Empty cells = no data available.