Tropical wetlands are a significant source of atmospheric methane (CH₄), but their importance to the global CH₄ budget is uncertain due to a paucity of direct observations. Net wetland emissions result from complex interactions and co-variation between microbial production and oxidation in the soil, and transport to the atmosphere. Here we show that phenology is the overarching control of net CH₄ emissions to the atmosphere from a permanent, vegetated tropical swamp in the Okavango Delta, Botswana, and we find that vegetative processes modulate net CH₄ emissions at sub-daily to inter-annual timescales. Without considering the role played by papyrus on regulating the efflux of CH₄ to the atmosphere, the annual budget for the entire Okavango Delta, would be under- or over-estimated by a factor of two. Our measurements demonstrate the importance of including vegetative processes such as phenological cycles into wetlands emission budgets of CH₄.

African elephants (Loxodonta africana) are megaherbivores of the African savannas requiring extensive ranges that can provide critical resources for their survival and reproduction at different spatiotemporal scales. We studied seasonal differences in home range sizes and daily distance to the nearest surface water sources by five male and 10 female African elephants in the eastern Okavango Panhandle in northern Botswana between 2014 and 2017. We hypothesized that (i) elephant home ranges would be larger in the wet than in the dry season (because critical resources tend to be less localized in the wet than in the dry season), (ii) the daily distance of the elephants to the nearest ephemeral surface water sources would be larger in the dry than in the wet season because many of the ephemeral water sources would be dry in the dry season and elephants would start moving towards permanent water sources such as rivers, and lastly (iii) that the differences in elephant home ranges and daily distance to water would differ between sexes. Our results showed that elephant home ranges were larger in the wet than in the dry season, and that they differed between sexes with female elephants having smaller home ranges in the late wet season. The mean daily distance to the nearest ephemeral surface water sources was larger in the dry than in the wet season. There was an inverse relationship between elephants' daily distance to permanent surface water and to ephemeral water sources. The findings indicate the need for large conservation areas and functional connectivity between landscapes to enable the highly mobile savanna elephants to access critical seasonal resources such as water and forage in semi‐arid savannas. Such landscapes are critical, especially in the face of climate change, when high air temperatures and droughts may exacerbate forage and water shortage and intensify human–elephant interactions in surrounding agroecosystems.

Elephants frequently raid crops within their ranges in Africa and Asia. These raids can greatly impact agricultural productivity and food security for farmers. Therefore, there is a need to explore cost‐effective measures that would reduce the susceptibility of crops and agricultural fields to elephant raiding, and further promote sustainable human–elephant coexistence. Previous studies have examined the susceptibility of crop fields to elephant raids using field characteristics such as field size and proximity to water sources. However, there are limited studies investigating how different crop types, individually and in their combinations, influence crop susceptibility to elephant raiding. This study utilized data collected from crop fields raided by the African savanna elephant (Loxodonta africana) between 2008 and 2018 in the eastern Okavango Panhandle, northern Botswana. Data on crops grown, number of crop‐raiding incidences for each crop, and elephant raiding incidences were recorded for each field assessed. Incidence risks (IR) and field risk value (RV) were computed using an adaptive epidemiological approach. The results showed that elephant raiding incidents varied significantly amongst crop types over space and time (p < .0001). Cereal crops (millet: Eleusine conaracana, maize: Zea mays) incurred a higher number of crop‐raiding incidents compared with leguminous crops (cowpea: Vigna unguiculata; groundnut: Arachis hypogea). Field RVs significantly varied depending on which crop was present in the field. There was a significant negative correlation between the number of crop types and the susceptibility of the field to raiding (r = −0.680, p < .0001). Our results suggest that the susceptibility of the fields to elephant raids could be minimized by selecting crop types and combinations less susceptible to elephant damage, thus enhancing food security for local subsistence farmers.

African elephants (Loxodonta africana) are megaherbivores of the African savanna that require extensive ranges to provide key resources critical for their survival and reproduction, both at spatial and temporal scales. We studied seasonal differences in home range sizes and daily distance travelled to the nearest ephemeral surface water sources by five male and ten female African elephants in the eastern Okavango Panhandle in northern Botswana between 2014-2017. We hypothesized that (i) elephant home ranges would be larger in the wet season than in the dry season (because forage and water sources tend to be more plentiful and widely distributed in the wet season than in the dry season, and elephants would not be restricted to localized resource areas), and that (ii) distances traveled by elephants to the nearest ephemeral surface water sources would be larger in the dry season than in the wet as these ephemeral water sources successively dry up. Our findings supported the hypotheses of the study. Elephants had larger home ranges in the wet season than in the dry season and the daily distances traveled to the nearest ephemeral surface water sources were larger in the dry season than in the wet season. The findings indicate the need to consider seasonal variations in elephant space use in land use planning and protected area management to minimize restricting elephants access to critical resources as seasons change or droughts intensify due to climate change.

1. Elephants frequently raid farmers’ crops within their ranges in Africa and Asia. This can have a large impact on agricultural productivity and food security for farmers. 2. Previous studies have examined susceptibility of crop fields to elephant raids using field characteristics such as field size and proximity to water sources. However, there are limited studies investigating how different crop types, individually and in their combinations influence crop susceptibility to elephant raiding. Also, spatio-temporal patterns in elephant crop raids in agro-ecological landscapes have not been extensively examined. 3. This study utilised data collected from crop fields raided by elephants between 2008 and 2018. Data on crops grown, the number of crop-raiding incidences for each crop, and elephant raiding incidences were recorded for each field assessed. Incidence risks (IR) and field risk value (RV) were computed using an adaptive epidemiological approach. 4. The results showed that elephant crop raiding incidents varied significantly amongst crop types, and over space and time (P<0.0001). Cereal crops (millet: Eleusine conaracana, maize: Zea mays) incurred a higher number of crop raiding incidents compared with leguminous crops (cowpea: Vigna unguiculata; groundnut: Arachis hypogea). Field RVs significantly varied depending on which crop was present in the field. There was a significant negative correlation between the number of crop types and the susceptibility of the field to raiding (R2 = -0.680, P<0.0001). 5. Our results suggest that the susceptibility of the fields to elephant raids could be minimised by selecting crop types and combinations less susceptible to elephant damage, thus enhancing food security for local subsistence farmers. Keywords: crop raiding, crop species, incidence risks, field risk value, food security, human-elephant conflict