Birth Pulse Research Articles

Persistence and propagation of a discrete-time map and PDE hybrid model with strong Allee effect

Persistence and propagation of species are fundamental questions in spatial ecology. This paper focuses on the impact of Allee effect on the persistence and propagation of a population with birth pulse. We investigate the threshold dynamics of an impulsive reaction–diffusion model and provide the existence of bistable traveling waves connecting two stable equilibria. To prove the existence of bistable waves, we extend the method of monotone semiflows to impulsive reaction–diffusion systems. We use the methods of upper and lower solutions and the convergence theorem for monotone semiflows to prove the global stability of traveling waves and their uniqueness up to translation. Then we enhance the stability of bistable traveling waves to global exponential stability. Numerical simulations illustrate our theoretical results.

NDVI predicts birth seasonality in historical Baja California Sur, Mexico: adaptive responses to arid ecosystems and the North American Monsoon

ABSTRACT Birth seasonality is a phenomenon whereby populations can be characterized by a single month or season in which births peak. While non-human animal research suggests that seasonal birth-pulses are related to variation in climate and local energy availability, social scientists debate the mechanisms responsible for it in humans. Here we investigate the role of precipitation, temperature, and energy availability on seasonal conception and birth pulses using a historical dataset from the Baja California peninsula – a hot, arid desert that experiences seasonal climatic fluctuations associated with the North American Monsoon. Analyses suggest that 1) local energy availability had a negative relationship with conception pulses; and 2) birth pulses had a positive relationship with local energy availability and a negative relationship with temperature. Taken together, our analyses suggest that women timed conceptions when local energy availability was lowest (challenging expectations of conception rates as simply reflecting ecological influences on female fecundity), so that children were born during the seasonal “green-up” associated with the North American Monsoon. Given our results, we speculate that birth seasonality represents a form of traditional ecological knowledge to improve neonate health and wellbeing.

Seasonal shifts in sociosexual behaviour and reproductive phenology in giraffe

Reproductive phenology (timing) is a heritable trait that confers a range of fitness or survival advantages. Giraffe (Giraffa spp.) breed year-round; however, some studies have suggested adaptive birth pulses, where demanding stages of reproduction coincide with seasonal increases in resource availability (phenological match). Here we use 3.5 years of demographic data to investigate the sociosexual behaviour and reproductive phenology of Angolan giraffe (G. g. angolensis) in the hyper arid northern Namib Desert, Namibia. We show that, in a highly seasonal desert ecosystem, giraffe gave birth to significantly more calves during the wet season. These calves were more likely to survive their first year of life, suggesting that season of birth may convey a fitness advantage. Furthermore, we show a decrease in sexual segregation between dominant (dark) adult males and adult females during the hot-dry season, suggesting a possible hot-dry season conception pulse. Finally, we demonstrate that the strongest correlation between the temporal pattern of births (wet-season pulse) and that of decreased sexual segregation (hot-dry season pulse) was time lagged by 15 months. This time lag corresponds to the period of gestation in giraffe, suggesting that a seasonal reduction in sexual segregation in this population may explain a seasonal birth pulse. These findings add to a sparse literature on the breeding phenology of giraffe, of asynchronously breeding megaherbivores, and of species with a gestation period of greater than 1 year. Results are discussed in terms of the possible environmental drivers of both season of conception and season of birth in this population. Furthermore, we highlight how predicted increases in seasonal instability due to climate change could reduce any putative fitness advantage associated with earlier birth dates. To maximize survival, many species align giving birth with periods where food resources are increased. We studied this phenomenon in giraffe, a large mammal that breeds year-round at all latitudes but, in seasonal environments, possibly aligns the most energetically demanding stages of reproduction with resource-rich periods. We demonstrate that in a highly seasonal desert ecosystem, giraffe gave birth to significantly more calves during the wet season. These calves were more likely to survive their first year of life, suggesting that the wet season birth pulse is adaptive. Furthermore, we show that dominant male giraffe are more likely to seek females in the hot-dry season, suggesting a conception pulse that helps to explain the wet season birth pulse. These results advance our understanding of giraffe social and mating behaviours and contribute to a better understanding of breeding phenology in megaherbivores.

A discrete/continuous time resource competition model and its implications

We use a mixed time model to study the dynamics of a system consisting of two consumers that reproduce only in annual birth pulses, possibly at different times, with interaction limited to competition for a resource that reproduces continuously. Ecological theory predicts competitive exclusion; this expectation is met under most circumstances, the winner being the species with the greater ‘power’, defined as the time average consumer level at the fixed point. Instability of that fixed point for the stronger competitor slightly weakens its domination, so that a resident species with an unstable fixed point can sometimes be invaded by a slightly weaker species, leading ultimately to coexistence. Differences in birth pulse times can lead to qualitatively different long-term coexistence behaviour, including cycles of different lengths or chaos. We also determine conditions under which the timing of an annual pulse of a toxin can change the balance of power.

Maternal and Microorganism Characteristics Cannot Predict Adverse Outcome in Pregnancies Complicated With Urinary Tract Infection

Background Previous studies revealed different results on the impact of urinary tract infection on pregnancy outcomes. Inconsistent data on adverse outcomes such as preterm delivery, low birth weight, and intrauterine growth restriction (IUGR) are reported in several studies. Methods Microorganisms were classified into 4 groups; Enterobacteriaceae, gram-positive cocci, fungi and others. Adverse pregnancy outcome was defined in the presence of IUGR, preterm delivery, low birth weight, and low appearance, pulse, grimace, activity, and respiration score. Adverse and no adverse outcome groups were compared. Results The total number of women with a positive urinary culture was 186. The most common isolated microorganism was Escherichia coli (n = 111, 59.7%). Among E. coli isolates, resistance was most common to ampicillin and trimethoprim sulfamethoxazole. The mean gestational week was 23.3 ± 1.12 for the urinary tract infection onset time and recurrence rate was 11.8% (n = 22). Oral antibiotics were prescribed to 164 outpatient women and hospitalization was required in 22 cases (11.8%). The rates of IUGR, low birth weight, low appearance, pulse, grimace, activity, and respiration, and preterm delivery were 11.8%, 11.3%, 6.9%, and 17.7%, respectively. There were 137 women (73.7%) in no adverse outcome group, whereas 49 women (26.3%) were in adverse outcome group. There was no significant difference in terms of bacteria group and maternal characteristics between 2 groups (P < 0.05 for all). Conclusions Maternal and microorganism characteristics are similar in pregnancies complicated with urinary infections in terms of adverse outcome. It is not possible to predict the ongoing pregnancy course by identifying maternal and microbiological features.

Reproductive Characteristics and Performance of the Florida Panther: A Retrospective Examination of Long-Term Data

AbstractKnowledge of reproductive characteristics and performance (RCP) is necessary to estimate a species' breeding output and provide indicators to evaluate population health. Long-term data are important because they provide insight into the roles of intrinsic and extrinsic factors in determining RCP and lifetime breeding output of individuals and productivity of populations. Here, I examine the RCP of the Florida panther Puma concolor coryi by using an extensive data set collected from 1981 to 2019. My objective is to establish baseline RCP parameters and to determine the factors that affect lifetime breeding output. Briefly, the results from a variety of data analyses show the following: 1) Florida panthers exhibit a spring (March–May) birth pulse; 2) minimum age at sexual maturity does not differ between sexes; 3) mean annual proportion of females reproducing, litter size, and birth rate progressively decrease with increasing maternal age; 4) mean litter sex ratio is male biased; 5) mean birth interval differs between successful and unsuccessful litters; 6) proportion of kittens that recruited into the breeding population is small; and 7) distribution of parentage and mating partners among individuals in litters of known mothers and fathers is right skewed. The results indicate that breeding output is limited both by low birth rate and small proportion of offspring recruiting into the breeding population. The decreasing RCP with increasing maternal age suggests that costs of reproduction and progressive body condition senescence are important factors limiting lifetime breeding output. Despite these inhibiting factors, the data came from a period of substantial population growth and expansion since 1995, so the RCP shown is productive for this species. Outcomes from this study provide important RCP information for wildlife managers to implement measurable criteria to assess trends in Florida panther breeding output and population health.

Persistence and Propagation of a PDE and Discrete-Time Map Hybrid Animal Movement Model With Habitat Shift Driven by Climate Change

Persistence or extinction of moving animal species is a fundamental question in spatial ecology. This paper focuses on the impact of habitat shift driven by climate change on the persistence and propagation of a population with birth pulse. We first present a class of impulsive reaction-diffusion models with heterogeneous nonlinear reaction in high-dimensional space and study their threshold dynamics. We provide the persistence criterion of the system in bounded domains, and prove the existence, uniqueness, and global attraction of a positive steady state. Then we extend the results from bounded domains to the whole space. Our results indicate how the speed of the shifting habitat edge and impulsive reproduction (or harvesting) rate determine the persistence and extinction of the population. Numerical simulations are presented to illustrate the theoretical results.

P139 Does Early Life Programming Influence Arterial Stiffness and Central Hemodynamics in Adulthood? Could Birth Cohort Effects be of Importance?

ObjectiveOur aim was to investigate possible associations between birth weight (BW) and adult carotid-femoral Pulse Wave Velocity (cfPWV) and augmentation pressure index (AIx).DesignThis study including 1598 participants, 340 elderly subjects and 1258 young-middle aged subjects from the Malmö Offspring Study with data on birth weight and gestational age (GA). Participants underwent cfPWV and AIx measurements with Sphygmocor® (AtCor, Australia). Analysis of data was performed with multiple linear regression models with adjustments for age, sex, GA, and risk factors. Furthermore, comparisons were made between participants born prematurely or at term, or born small-for-gestational-age (SGA) or appropriate-for-gestational-age (AGA).ResultsBirth weight was positively associated with cfPWV after full adjustment (b = 0.057; p < 0.001), Figure 1, a finding that remained significant in the younger age group 18–27 years (b = 0.138, p = 0.008). Furthermore, birth weight was inversely associated with AIx (b = −0.058, p = 0.001). Subjects born SGA had significantly higher AIx (p = 0.007) and MAP (p = 0.037) compared to AGA born. Preterm-born subjects showed significantly higher systolic blood pressure compared to term-born (p = 0.034). Also, BW was inversely associated with MAP (b = −0.058, p = 0.017) and SBP (b = −0.047, p = 0.031), respectively.ConclusionOur findings suggest that changes in total peripheral resistance, rather than decreased arterial stiffness, may explain the observed inverse association between birth weight and SBP. Furthermore, the association between birth weight and cfPWV, shown strongest in the youngest age group (birth cohort), could possibly be explained by increasing maternal overweight/obesity. This calls for screening of risk factors in subjects with adverse conditions at birth.Figure 1Simple regression of birth weight and pulse wave velocity.

Optimizing spatial and seasonal deployment of vaccination campaigns to eliminate wildlife rabies.

Understanding how the spatial deployment of interventions affects elimination time horizons and potential for disease re-emergence has broad application to control programmes targeting human, animal and plant pathogens. We previously developed an epidemiological model that captures the main features of rabies spread and the impacts of vaccination based on detailed records of fox rabies in eastern Germany during the implementation of an oral rabies vaccination (ORV) programme. Here, we use simulations from this fitted model to determine the best vaccination strategy, in terms of spatial placement and timing of ORV efforts, for three epidemiological scenarios representative of current situations in Europe. We found that consecutive and comprehensive twice-yearly vaccinations across all regions rapidly controlled and eliminated rabies and that the autumn campaigns had the greater impact on increasing the probability of elimination. This appears to result from the need to maintain sufficient herd immunity in the face of large birth pulses, as autumn vaccinations reach susceptible juveniles and therefore a larger proportion of the population than spring vaccinations. Incomplete vaccination compromised time to elimination requiring the same or more vaccination effort to meet similar timelines. Our results have important practical implications that could inform policies for rabies containment and elimination in Europe and elsewhere. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'. This theme issue is linked with the earlier issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'.

A pest control model with birth pulse and residual and delay effects of pesticides

Pesticides often cause residual and delayed effects on pests. Considering these effects, we use a pollution emission model to simulate the process of spraying pesticides. Many pests reproduce only at a fixed time in a year. So a pest control model with birth pulse and spraying pesticides is proposed. Using the limit system of the developed model, we analyze the dynamics of the system. The stability of the trivial equilibrium and the positive equilibrium of the model is analyzed, and the threshold conditions of pest eradication and permanence of the system are given. We obtain the optimal frequency of spraying pesticides by numerical simulations. The important parameters related to the pest eradication or permanence of the system are given by analyzing the sensitivity of the parameters. Finally, biological explanations are provided.

A reaction-diffusion population growth equation with multiple pulse perturbations

During the pest growth generations there exist a number of internal and external perturbations including birth pulses and pulse pesticide applications, which result in a complex growth pattern within each pest growth generation due to the variation of perturbation timings. In order to show how multiple pulse perturbations affect the dynamics of the pest population, we have extended the classical Fisher reaction-diffusion equation by involving instant birth and control perturbations. The main results indicate that the pulse perturbations have a remarkable influence on the existence and stability of a spatially homogeneous periodic solution. In particular, the birth rate and killing efficacy can affect the traveling wave and its spreading speed, while the timing of pesticide application does not make any effects on those threshold conditions. However, numerical investigations reveal that the timing of pesticide applications can significantly affect the spatial distributions of the pest population. Within each generation too early or too late pesticide application could result in a faster growth and wider spread of the pest, and the optimal timing of pesticide application is the middle of each generation provided that the efficacy of the pesticide is relatively low. Bifurcation analyses reveal that even generations and odd generations display a different spatial pattern, which depict some important issues related to the pest control and pest management, for example the different control strategies should be adopted for even and odd generations. To address how the spatial heterogeneity affects on the cost of the pest control, we further formulate the cost function to investigate the optimal pest control strategy, and the optimal spatial dependent killing rates which minimize the cost have been obtained numerically.

Spatial Invasion of a Birth Pulse Population with Nonlocal Dispersal

We propose an impulsive integro-differential model to describe the dynamics of an invading species with a pulsive reproduction stage and a nonlocal dispersal stage. We first establish a threshold-t...

Population viability and harvest sustainability for Madagascar lemurs.

Subsistence hunting presents a conservation challenge by which biodiversity preservation must be balanced with safeguarding of human livelihoods. Globally, subsistence hunting threatens primate populations, including Madagascar's endemic lemurs. We used population viability analysis to assess the sustainability of lemur hunting in Makira Natural Park, Madagascar. We identified trends in seasonal hunting of 11 Makira lemur species from household interview data, estimated local lemur densities in populations adjacent to focal villages via transect surveys, and quantified extinction vulnerability for these populations based on species-specific demographic parameters and empirically derived hunting rates. We compared stage-based Lefkovitch with periodic Leslie matrices to evaluate the impact of regional dispersal on persistence trajectories and explored the consequences of perturbations to the timing of peak hunting relative to the lemur birth pulse, under assumptions of density-dependent reproductive compensation. Lemur hunting peaked during the fruit-abundant wet season (March-June). Estimated local lemur densities were roughly inverse to body size across our study area. Life-history modeling indicated that hunting most severely threatened the species with the largest bodies (i.e., Hapalemur occidentalis, Avahi laniger, Daubentonia madagascariensis, and Indri indi), characterized by late-age reproductive onsets and long interbirth intervals. In model simulations, lemur dispersal within a regional metapopulation buffered extinction threats when a majority of local sites supported growth rates above the replacement level but drove regional extirpations when most local sites were overharvested. Hunt simulations were most detrimental when timed to overlap lemur births (a reality for D. madagascariensis and I. indri). In sum, Makira lemurs were overharvested. Regional extirpations, which may contribute to broad-scale extinctions, will be likely if current hunting rates persist. Cessation of anthropogenic lemur harvest is a conservation priority, and development programs are needed to help communities switch from wildlife consumption to domestic protein alternatives.

Effects of Occupational Tobacco Exposure on Mother and Foetus in Beedi Rollers

Background and objectives: Beedi rolling is a popular household occupation amongst the economically poor female population of coastal Karnataka districts. This study aimed to identify the effects of occupational tobacco exposure on the beedi rolling pregnant mother and her neonate. The objectives were to study the maternal outcomes with respect to hypertension in pregnancy, anemia, abruptio-placenta, preterm labor and the neonatal outcomes such as low birth weight, low appearance, pulse grimace, activity, respiration (APGAR) and clinical assessment of nutrition status (CANS) score. Methods: This prospective cohort study was conducted in a tertiary care hospital in Mangaluru from February 2014 to June 2015. A sample size of 500 was calculated with a 95% confidence level and 85% power. Cohort groups of 250 each were randomized as beedi rollers and non-beedi rollers based on the history of exposure and were prospectively followed till delivery. Results: The study results showed overall complications of 37.6 % among the beedi rollers which was clinically and statistically significant. Among the beedi rollers, 22.4% mothers had hypertension in pregnancy, of which 13.4%, had gestational hypertension, 8.2% pre-eclampsia, 0.4% had eclampsia, 27.6% were anaemic, and 9.6% had fetal growth restriction. There was no increase in the incidence of preterm labor, abrubtio-placenta. Our study also showed an increased risk of low birth weight (29.4%), but no significant difference in APGAR scores and CANS score among both groups. Based on the ROC curve we found, rolling 425 beedis can be taken as a safe limit during pregnancy with a sensitivity of 73.4% and specificity of 53.2% and 22 weeks period of gestation can be taken as safe limit up to which beedis can be rolled during pregnancy with a sensitivity of 61.7% and specificity of 64.1%. Clinical significance: In this study, dreadful complications can be attributed to beedi rolling. Majority of it can be prevented by health education and simple preventive measures such as using masks and gloves while rolling beedis for which further studies are warranted.

The roles of migratory and resident birds in local avian influenza infection dynamics.

Migratory birds are an increasing focus of interest when it comes to infection dynamics and the spread of avian influenza viruses (AIV). However, we lack detailed understanding migratory birds' contribution to local AIV prevalence levels and their downstream socio-economic costs and threats.To explain the potential differential roles of migratory and resident birds in local AIV infection dynamics, we used a susceptible-infectious-recovered (SIR) model. We investigated five (mutually non- exclusive) mechanisms potentially driving observed prevalence patterns: 1) a pronounced birth pulse (e.g. the synchronised annual influx of immunologically naïve individuals), 2) short-term immunity, 3) increase of susceptible migrants, 4) differential susceptibility to infection (i.e. transmission rate) for migrants and residents, and 5) replacement of migrants during peak migration.SIR models describing all possible combinations of the five mechanisms were fitted to individual AIV infection data from a detailed longitudinal surveillance study in the partially migratory mallard duck (Anas platyrhynchos). During autumn and winter, the local resident mallard community also held migratory mallards that exhibited distinct AIV infection dynamics.Replacement of migratory birds during peak migration in autumn was found to be the most important mechanism driving the variation in local AIV infection patterns. This suggests that a constant influx of migratory birds, likely immunological naïve to locally circulating AIV strains, is required to predict the observed temporal prevalence patterns and the distinct differences in prevalence between residents and migrants.Synthesis and applications. Our analysis reveals a key mechanism that could explain the amplifying role of migratory birds in local avian influenza virus infection dynamics; the constant flow and replacement of migratory birds during peak migration. Aside from monitoring efforts, in order to achieve adequate disease management and control in wildlife - with knock-on effects for livestock and humans, - we conclude that it is crucial, in future surveillance studies, to record host demographical parameters such as population density, timing of birth and turnover of migrants.

A sex-structured model with birth pulse and release strategy for the spread of Wolbachia in mosquito population

Dengue fever is one of the most important diseases causing illness and death all over the world, which brings tremendous threat to peoples’ life and property security, especially in the undeveloped areas. The main vector, Aedes aegypti, must be controlled to prevent the transmission of dengue. There are a variety of methods to control it. Wolbachia is an innovative bacterium which breaks the dengue transmission cycle for its characteristics of cytoplasmic incompatibility and maternal transmission. In this paper, a sex-structured model with birth pulse is established to study the spread of Wolbachia in mosquito population. The results show that if the maternal transmission is perfect, Wolbachia will spread successfully. Moreover, all the mosquitoes will be infected with Wolbachia. If the maternal transmission is imperfect, there are two locally asymptotically stable periodic solutions. One is Wolbachia-extinction periodic solution, and the other is part replacement periodic solution. Numerical simulations show that the initial occupancy of Wolbachia-infected mosquitoes has an important effect on the success of part replacement strategy. If the initial occupancy is relatively large, the part replacement strategy can be successful. Furthermore, in consideration of the fact that the initial occupancy cannot be always large enough in the wild nature, to release Wolbachia-infected mosquitoes artificially into the wild nature becomes necessary. Therefore, we add a release strategy into the sex-structured model with birth pulse for further analysis. The condition to ensure the stability of the Wolbachia total replacement periodic solution is obtained. Finally, the effect of the release quantity is simulated numerically.

Support for viral persistence in bats from age-specific serology and models of maternal immunity

Spatiotemporally-localised prediction of virus emergence from wildlife requires focused studies on the ecology and immunology of reservoir hosts in their native habitat. Reliable predictions from mathematical models remain difficult in most systems due to a dearth of appropriate empirical data. Our goal was to study the circulation and immune dynamics of zoonotic viruses in bat populations and investigate the effects of maternally-derived and acquired immunity on viral persistence. Using rare age-specific serological data from wild-caught Eidolon helvum fruit bats as a case study, we estimated viral transmission parameters for a stochastic infection model. We estimated mean durations of around 6 months for maternally-derived immunity to Lagos bat virus and African henipavirus, whereas acquired immunity was long-lasting (Lagos bat virus: mean 12 years, henipavirus: mean 4 years). In the presence of a seasonal birth pulse, the effect of maternally-derived immunity on virus persistence within modelled bat populations was highly dependent on transmission characteristics. To explain previous reports of viral persistence within small natural and captive E. helvum populations, we hypothesise that some bats must experience prolonged infectious periods or within-host latency. By further elucidating plausible mechanisms of virus persistence in bat populations, we contribute to guidance of future field studies.

Model selection for integrated pest management with stochasticity

In Song and Xiang (2006), an integrated pest management model with periodically varying climatic conditions was introduced. In order to address a wider range of environmental effects, the authors here have embarked upon a series of studies resulting in a more flexible modeling approach. In Akman et al. (2013), the impact of randomly changing environmental conditions is examined by incorporating stochasticity into the birth pulse of the prey species. In Akman et al. (2014), the authors introduce a class of models via a mixture of two birth-pulse terms and determined conditions for the global and local asymptotic stability of the pest eradication solution. With this work, the authors unify the stochastic and mixture model components to create further flexibility in modeling the impacts of random environmental changes on an integrated pest management system. In particular, we first determine the conditions under which solutions of our deterministic mixture model are permanent. We then analyze the stochastic model to find the optimal value of the mixing parameter that minimizes the variance in the efficacy of the pesticide. Additionally, we perform a sensitivity analysis to show that the corresponding pesticide efficacy determined by this optimization technique is indeed robust. Through numerical simulations we show that permanence can be preserved in our stochastic model. Our study of the stochastic version of the model indicates that our results on the deterministic model provide informative conclusions about the behavior of the stochastic model.

Female reproductive success and calf survival in a North Sea coastal bottlenose dolphin (Tursiops truncatus) population.

Between-female variation in reproductive output provides a strong measure of individual fitness and a quantifiable measure of the health of a population which may be highly informative to management. In the present study, we examined reproductive traits in female bottlenose dolphins from the east coast of Scotland using longitudinal sightings data collected over twenty years. From a total of 102 females identified between 1997 and 2016, 74 mothers produced a collective total of 193 calves. Females gave birth from 6 to 13 years of age with a mean age of 8. Calves were produced during all study months, May to October inclusive, but showed a seasonal birth pulse corresponding to the regional peak in summer water temperatures. Approximately 83% (n = 116) of the calves of established fate were successfully raised to year 2–3. Of the known mortalities, ~45% were first-born calves. Calf survival rates were also lower in multiparous females who had previously lost calves. A mean inter-birth interval (IBI) of 3.80 years (n = 110) and mean fecundity of 0.16 was estimated for the population. Calf loss resulted in shortened IBIs, whilst longer IBIs were observed in females assumed to be approaching reproductive senescence. Maternal age and size, breeding experience, dominance, individual associations, group size and other social factors, were all concluded to influence reproductive success (RS) in this population. Some females are likely more important than others for the future viability of the population. Consequently, a better knowledge of the demographic groups containing those females showing higher reproductive success would be highly desirable for conservation efforts aimed at their protection.

How Does Africa's Most Hunted Bat Vary Across the Continent? Population Traits of the Straw-Coloured Fruit Bat (Eidolon helvum) and Its Interactions with Humans

The straw-coloured fruit bat, Eidolon helvum, is a common and conspicuous migratory species, with an extensive distribution across sub-Saharan Africa, yet hunting and habitat loss are thought to be resulting in decline in some areas. Eidolon helvum is also a known reservoir for potentially zoonotic viruses. Despite E. helvum's importance, ecological and behavioural traits are poorly described for this species. Here we present extensive data on the distribution, migration patterns, roost size, age and sex composition of 29 E. helvum roosts from nine countries across tropical Africa, including roosts not previously described in the literature. Roost age and sex composition were dependent on timing of sampling relative to the annual birth pulse. Rather than a single ‘breeding season’ as is frequently reported for this species, regional asynchrony of reproductive timing was observed across study sites (with birth pulses variably starting in March, April, September, November or December). Considered together with its genetic panmixia, we conclude that the species has a fluid, fission-fusion social structure, resulting in different roost ‘types’ at different times of the year relative to seasonal reproduction. Bat-human interactions also varied across the species' geographical range. In the absence of significant hunting, large urban colonies were generally tolerated, yet in regions with high hunting pressure, bats tended to roost in remote or protected sites. The extensive quantitative and qualitative data presented in this manuscript are also valuable for a wide range of studies and provide an historical snapshot as its populations become increasingly threatened.