Marlee A. Tucker et al. (including T. Adams, M.J.Chase), Behavioral responses of terrestrial mammals to COVID-19 lockdowns. Science 380,1059-1064 (June,2023). Open access, DOI:10.1126/science.abo6499 Policies to reduce human movement during the early months of the COVID-19 pandemic produced a kind of natural experiment to observe how human activities affect animal behavior. Using GPS tracking data from 2300 individual mammals of 43 species, Tucker et al. documented changes in mammal movement patterns during the spring of 2020 compared with the previous year (see the Perspective by St. Clair and Raymond). In locations with strict lockdown policies, animals traveled longer distances during the lockdown period. In highly populated areas, mammals moved less frequently and were closer to roads than they were before the pandemic. These results demonstrate how human activities constrain animal movement and what happens when those activities cease. —Bianca Lopez
R. M. Huang, R.J van Aarde, S.L.Pimm, M.J.Chase, K.Leggett, Mapping Potential Connections between Southern Africa’s elephant Populations, PLOS ONE 17(10): e0275791. https://doi.org/10.1371/journal.pone.0275791 Oct. 11, 2022. From Abstract “Southern Africa spans nearly 7 million km2 and contains approximately 80% of the world’s savannah elephants (Loxodonta africana) mostly living in isolated protected areas. Here we ask what are the prospects for improving the connections between these populations? Wecombine 1.2 million telemetry observations from 254 elephants with spatial data on environmental factors and human land use across eight southern African countries. Telemetry data show what natural features limit elephant movement and what human factors, including fencing, further prevent or restrict dispersal.” Open access, download PDF
Adams T.S.F., Leggett K.E.A, Chase, M.J. & Tucker M. (July, 2022). Who is adjusting to whom? Differences in elephant diel activity in wildlife corridors across different human-modified landscapes in Frontiers in Conservation. DOI:10.3389/fcosc.2022.872472. Open access, free to download: https://www.frontiersin.org/articles/10.3389/fcosc.2022.872472 from Abstract: The global impact of increased human activities has consequences on the conservation of wildlife. Understanding how wildlife adapts to increased human pressures with urban expansion and agricultural areas is fundamental to future conservation plans of any species. However, there is a belief that large wild free-ranging carnivores and ungulates, cannot coexist with people, limited studies have looked at wildlife movements through differing human-dominated landscapes at finer spatial scales, in Africa. This information is vital as the human population is only going to increase and the wildlife protected areas decrease. Our findings demonstrate that elephant diel patterns of use of the wildlife corridor differs based on the surrounding human land-uses on an hourly basis and daily basis, revealing potential adaptation and risk avoidance behaviour.
Adams, T.A., Chase, M.J., Leggett, K., Elephant movements in different human land-uses in Chobe District, Botswana , Pachyderm No 62 June 2021, https://pachydermjournal.org/index.php/pachyderm/article/view/445/460 from Abstract: We have a limited understanding of the effects that an increasing human population and urban and agricultural development are having on elephant movements in Botswana. Elephant movements are complex because they are influenced by a wide range of location-specific variables. This study aimed to investigate how elephants move through different human-dominated landscapes in the Chobe District, Botswana… It is vital for any wildlife management plan that the spatial movements of key conservation species are thoroughly understood, in order to formulate informed management decisions and create an integrated land-use management plan that enables both development and elephant coexistence.”
R. Francis, G. Bino, V. Inman, K. Brandis, R.T. Kingsford, The Okavango Delta’s waterbirds – Trends and threatening processes, Global Ecology and Conservation, Volume 30, 2021, e01763, ISSN 2351-9894, https://doi.org/10.1016/j.gecco.2021.e01763 https://www.sciencedirect.com/science/article/pii/S2351989421003139 from Abstract: The Okavango Delta is renowned as an extraordinary ecosystem of high biodiversity, listed as both a Ramsar and World Heritage Site, with part protected in the Moremi Game Reserve. This extensive floodplain ecosystem has 444 recorded bird species, with just under a quarter of these waterbirds, including at least 16 breeding and 4 threatened (1 endangered, 3 vulnerable) species. Despite the global importance of this ecosystem, and its transboundary nature, there are surprisingly few long-term assessments of status of the ecosystem or waterbird communities, a key indicator of ecosystem health, with threats such as upstream water extraction, and climate change threatening its outstanding biodiversity…”
Van der Weyde, L. K., Tobler, M. W., Gielen, M. C., Cozzi, G., Weise, F. J., Adams, T., Bauer, D., Bennitt, E., Bowles, M., Brassine, A., Broekhuis, F., Chase, M., Collins, K., Finerty, G. E., Golabek, K., Hartley, R., Henley, S., Isden, J., Keeping, D., … Flyman, M. V. (2021). Collaboration for conservation: Assessing countrywide carnivore occupancy dynamics from sparse data. Diversity and Distributions, 00, 1– 13. Open Access to paper: https://doi.org/10.1111/ddi.13386 “Assessing the distribution and persistence of species across their range is a crucial component of wildlife conservation. It demands data at adequate spatial scales and over extended periods of time, which may only be obtained through collaborative efforts, and the development of methods that integrate heterogeneous datasets. We aimed to combine existing data on large carnivores to evaluate population dynamics and improve knowledge on their distribution nationwide.”
Francis R.J., Kingsford, R.T., Brandis, K.J., Murray-Hudson, M. Urban waste no replacement for natural foods—Marabou storks in Botswana, Journal of Urban Ecology, Volume 7, Issue 1, 2021, juab003, https://doi.org/10.1093/jue/juab003 “We compared diets of marabou storks Leptoptilos crumenifer foraging from urban landfills and natural areas in northern Botswana using stable isotope analyses and inductively coupled plasma mass spectrometry on moulted feathers….Urban waste stored in open air landfills is altering some marabou diets, affecting their natural trophic niche, resulting in the consumption (and regurgitation) of large amounts of plastic, and exposing marabou to potentially chronic levels of trace metals. Despite the marabou’s apparent resilience to this behavioural shift, it could have long-term effects on the population of the marabou stork, particularly considering Botswana has some of the few regular marabou breeding colonies in southern Africa.”
Pearson VR, Bosse JB, Koyuncu OO, Scherer J, Toruno C, Robinson R, Abegglen LM, Schiffman JD, Enquist LW, Rall GF (2021) Identification of African Elephant Polyomavirus in wild elephants and the creation of a vector expressing its viral tumor antigens to transform elephant primary cells. PLoS ONE 16(2) https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0244334 “Wild elephant populations are declining rapidly due to rampant killing for ivory and body parts, range fragmentation, and human-elephant conflict. Wild and captive elephants are further impacted by viruses, including highly pathogenic elephant endotheliotropic herpesviruses. Moreover, while the rich genetic diversity of the ancient elephant lineage is disappearing, elephants, with their low incidence of cancer, have emerged as a surprising resource in human cancer research for understanding the intrinsic cellular response to DNA damage. However, studies on cellular resistance to transformation and herpesvirus reproduction have been severely limited, in part due to the lack of established elephant cell lines to enable in vitro experiments.”
Francis R.J., Brandis, K.J., Kingsford, R.T., Callaghan, C.T. July 2020. Quantifying bird diversity at three sites of differing herbivore presence. Journal of Ornithology DOI. “”Large herbivores directly and indirectly influence ecosystem function, positively and negatively affecting diversity of plants and animals, including birds. Such cascading effects are clearly important, particularly given ongoing global declines in large herbivores and many avian communities. We examined relationships between bird diversity… and, explored the role that herbivore presence plays in ecosystem functioning considering bird species richness…” https://doi.org/10.1007/s10336-020-01804-6.
Adams, T., Mwezi, I., & Jordan, N. July, 2020. Panic at the disco: Solar-powered strobe light barriers reduce field incursion by African elephants Loxodonta africana in Chobe District, Botswana. “Managing interactions between humans and wild elephants is a complex problem that is increasing as a result of agricultural and urban expansion into and alongside protected areas. Mitigating negative interactions requires the development of new tools to reduce competition and promote coexistence…Our findings demonstrate the efficacy of light barriers to reduce negative human–elephant interactions in rural communities. Oryx, 1-8. www.doi.org/10.1017/S0030605319001182
Schlossberg, S., Chase, M.J., Gobush, K., Wasser, S., Lindsay, K. State-space models reveal a continuing elephant poaching problem in most of Africa. Scientific Reports 10, 10166. June, 2020. The most comprehensive data on poaching of African elephants comes from the Monitoring the Illegal Killing of Elephants (MIKE) program, which reports numbers of illegally killed carcasses encountered by rangers. To provide more accurate information on trends in elephant poaching, we analyzed MIKE data using state-space models. State-space models account for missing data and the error inherent when sampling carcasses. Our results suggest that poaching for ivory has not diminished across most of Africa, only in Eastern Africa have poaching rates decreased since 2011. Continued vigilance and anti-poaching efforts will be necessary to combat poaching and to conserve African elephants. https://doi.org/10.1038/s41598-020-66906-w
Schlossberg S., Gobush K., Chase, M., Elkan P., Grossman F., Kohi E., Understanding the Drivers of Mortality in African Savannah Elephants, Ecological Applications 0(0), May 2020, e2131; Populations of African savannah elephants (Loxodonta africana ) have been declining due to poaching, human–elephant conflict, and habitat loss. Understanding the causes of these declines could aid in stabilizing elephant populations. https://doi.org/10.1002/eap.2131
Inman, V., Lyons M., Automated Inundation Mapping Over Large Areas Using Landsat Data and Google Earth Engine, Remote Sensing, April 2020, 12(8), 1348; Accurate inundation maps for flooded wetlands and rivers are a critical resource for their management and conservation. Inundation classification in the Okavango Delta is complex owing to the spectral overlap between inundated areas covered with aquatic vegetation and dryland vegetation classes on satellite imagery, and classifications have predominately been implemented on broad spatial resolution imagery. We present the longest time series to date (1990–2019) of inundation maps for the peak flood season at a high spatial resolution (30 m) for the Okavango Delta. Download: https://doi.org/10.3390/rs12081348
Francis, R., Lyons M., Kingsford R., Brandis K., Counting Mixed Breeding Aggregations of Species Using Drones: Lessons from Waterbirds on Semi-Automation, Remote Sensing, April 2020, 12, 1185; Using drones to count wildlife saves time and resources and allows access to difficult or dangerous areas. We collected drone imagery of breeding waterbirds at colonies in the Okavango Delta (Botswana) and Lowbidgee floodplain (Australia). We developed a semi-automated counting method, using machine learning, and compared effectiveness of freeware and payware in identifying and counting waterbird species (targets) in the Okavango Delta. We tested transferability to the Australian breeding colony. Download: doi:10.3390/rs12071185
Garvin, S. The Jumbo Problem of Living with Elephants; varying perspectives on human-elephant conflict in Chobe District, Botswana. Tropical Resources Bulletin, 36. 9-16. Completed 2017, made available 2020. Chobe District is undergoing rapid changes; development is putting pressure on wildlife movements throughout townships. With these changes, identifying ways for species to live together will be crucial to maintaining elephant population viability and human safety. This study utilizes semi-structured interviews and discourse analysis techniques to look across a wide variety of sectors at perspectives of the problems with human-elephant coexistence. Download here
Inman V., Kingsford R., Chase M., Leggett K., Drone-based effective counting and aging of hippopotamus (Hippopotamus amphibius) in the Okavango Delta in Botswana, Plos One, December 2019. Accurately estimating hippopotamus (Hippopotamus amphibius) numbers is difficult due to their aggressive nature, amphibious lifestyle, and habit of diving and surfacing. Traditionally, hippos are counted using aerial surveys and land/boat surveys. We compared estimates of numbers of hippos in a lagoon in the Okavango Delta, counted from land to counts from video taken from a DJI Phantom 4TM drone, testing for effectiveness at three heights (40 m, 80 m, and 120 m) and four times of day (early morning, late morning, early afternoon, and late afternoon). In addition, we determined effectiveness for differentiating age classes (juvenile, subadult, and adult), based on visual assessment and measurements from drone images, at different times and heights. Download: https://doi.org/10.1371/journal.pone.0219652
O’Connor D., Stacy-Dawes J., Muneza A., Fennessy J., Gobush K., Chase M., Updated geographic range maps for Giraffe, Giraffa spp., throughout sub-Saharan Africa, and implications of distributions for conservation, Mammal Review, Vol.49, Iss 4, October 2019. Giraffe populations have declined in abundance by almost 40% over the last three decades, and the geographic ranges of the species (previously believed to be one, now defined as four species) have been significantly reduced or altered. With substantial changes in land uses, loss of habitat, declining abundance, translocations, and data gaps, the existing geographic range maps for giraffe need to be updated. Download: https://onlinelibrary.wiley.com/doi/epdf/10.1111/mam.12165
Wasser, S.K., Gobush, K.S. Conservation: Monitoring Elephant Poaching to Prevent a Population Crash, Current Biology, Vol.29, Issue 13, 8July 2019, pgs. R627-30. https://www.sciencedirect.com/science/article/pii/S096098221930702X Open access.
Schlossberg and colleagues meticulously document a substantial rise in poaching in northern Botswana between 2014 and 2018. Signs of poaching include: a six-fold increase in fresh elephant carcasses and a significant increase in the carcass ratio (total carcass count divided by the sum of live and dead elephants). All fresh and recent carcasses inspected showed clear signs of being poached. Schlossberg and colleagues identified five poaching hotspots characterized by a recent increase in the number and clustering of carcasses and a decrease in live elephants. Equally important, they systematically explore numerous plausible alternative explanations for the observed mortality patterns (e.g. drought, food shortage, crowding and human elephant conflict), none of which are supported by the data.
Schlossberg, S., Chase, M.J., Sutcliffe, R. Evidence of a Growing Elephant Poaching Problem in Botswana, Current Biology 29, July 2019. Botswana holds roughly one-third of Africa’s remaining savannah elephants (Loxodonta africana) and will play a key role in the future conservation of this species. To date, Botswana has been one of the safest countries for elephants, with little poaching reported. Here, we present evidence of a new outbreak of elephant poaching for ivory in northern Botswana. sciencedirect.com/science/article/pii/S096098221930675X
Inman, V.L., Leggett, K., Observations on the response of a pod of hippos to a dead juvenile hippo (Hippopotamus amphibious, Linnaeus 1758). African Journal of Ecology. May 2019. DOI: 10.1111/aje 12644. Hippos are gregarious animals, generally occurring as pods comprising females and their young, a dominant male, and subordinate males. The most stable relationship in a pod is between a mother and her young. Within a pod, the dominant male has exclusive mating rights and has been known to commit infanticide, which is thought to reduce the interbirthing interval of the female. This note documents detailed observations of an adult female hippo and pod interacting with a dead juvenile hippo within their aquatic habitat over the course of eleven hours. Download: https://www.researchgate.net/publication/333458258_Observations_on_the_response_of_a_pod_of_hippos_to_a_dead_juvenile_hippo_Hippopotamus_amphibius_Linnaeus_1758
Purdon A., Mole M. A., Chase M.J., van Aarde R. J. Partial Migration in Savanna Elephant Populations Distributed Across Southern Africa. Scientific Reports 8, Article number 11331. July 2018. Migration is an important, but threatened ecological process. Conserving migration requires the maintenance of functional connectivity across sufficiently large areas. Therefore, we need to know if, where and why species migrate. Elephants are highly mobile and can travel long distances but we do not know if they migrate. Here, we analysed the movement trajectories of 139 savanna elephants (Loxodonta africana) within eight clusters of protected areas across southern Africa to determine if elephants migrate, and if so, where, how and why they migrate. Download: https://www.nature.com/articles/s41598-018-29724-9
Schlossberg S., Chase M.J., Griffin C.R.. Poaching and human encroachment reverse recovery of African savannah elephants in south-east Angola despite 14 years of peace. Plos One, article 10.1371. March 2018. Angola’s elephant population represents a key linkage between the larger populations of Namibia and Botswana. Elephants in Angola were decimated during the 1975±2002 Angolan civil war, but a 2005 survey showed that populations were recolonizing former habitats. Between 2005 and 2015, no research was permitted on elephants in Angola, but elsewhere in Africa many elephant populations experienced a poaching crisis. In 2015, we were able to resume elephant research in Angola. We used aerial surveys and satellite monitoring of collared elephants to determine the current status of elephant populations in Angola and to learn how human populations may be affecting elephant habitat usage. Download: http://journals.plos.org/plosone/article?id=10.371/journal.pone.0193469
Schlossberg S., Chase M.J., Griffin C.R.. Using Species Traits to Predict Detectability of Animals on Aerial Surveys. Ecological Applications. January 2018. Volume 28, Issue 1, pages 106-118. In animal surveys, detectability can vary widely across species. This study hypothesized that detectability of animals should be a function of species traits such as mass, color, and mean herd size. The research tested these hypotheses with double-observer aerial surveys of 10 mammal species in northern Botswana. We found support for effects of mass and an interaction between herd size and mean herd size on detectability. To our knowledge, this represents the first time that a mechanistic model for detectability of animals has been used to predict detectability for new species. The approach taken in this paper can potentially be used with a variety of taxa and may provide new opportunities to apply detectability corrections where they have not been possible before. Access: onlinelibrary.wiley.com/wol1/doi/10.1002/eap.1632/full
Lindsay, K., Chase, M.J., Landen, K.A., Nowak, K. The Shared Nature of Africa’s elephants. Biological Conservation, Vol. 215, Nov. 2017, pages 260-267. Using data from the African Elephant Status Report 2016, where savanna elephant data are based mostly on the recently completed Great Elephant Census, we show that 76% of elephants are found in populations spread across one or more national borders. This blurring of strictly national populations makes a split-listing of elephants between two CITES appendices—and varying levels of protection—inconsistent with ecological reality and conservation best practice. Download: www.sciencedirect.com/science/article/pii/S0006320717303890 Read more about “The Shared Nature…” in National Geographic news: Poachers Work Across Borders, so Why Not Conservation Efforts?.
Adams, T.A., Chase, M.J., Attard, A., Leggett, K. A preliminary study of stakeholders’ opinions and perceptions of elephants and elephant management in Botswana. Pachyderm, No.58 2017. This preliminary study aims to determine stakeholders’ opinions and perceptions of elephants and elephant management in Botswana. The study provides an insight into stakeholders’ opinions and perceptions of elephant management in Botswana, providing inputs for an improved management strategy, aimed at reducing the incidence and impact of human–elephant conflict in Botswana. Download: www.pachydermjournal.org/index.php/pachy/article/view/438/352
Rogan, M.S., Lindsay, P.A., Tambling, C.J., Golabek, K.A., Chase, M.J., Collins, K., and McNutt, J.W. June, 2017. Illegal bushmeat hunter compete with predators and threaten wild herbivore populations in global tourism hotspot. Biological Conservation, 210:233-242. Illegal bushmeat hunting is a global threat to wildlife, but its secretive and unregulated nature undermines efforts to mitigate its impacts on wildlife and wildlife-based industries. We investigated the scale of illegal bushmeat hunting in the Okavango Delta, Botswana (~ 20,000 km²) to assess its potential contribution to wildlife population declines.Download:https://www.researchgate.net/publication/316563464_Illegal_bushmeat_hunters_compete_with_predators_and_threaten_wild_herbivore_populations_in_a_global_tourism_hotspot
Gravett, N., Bhagwandin, A., Sutcliﬀe, R., Landen, K., Chase, M., Lyamin, O.I., Siegel, J.M., Manger, P.R. Inactivity/sleep in two wild free-roaming African elephant matriarchs – Does large body size make elephants the shortest mammalian sleepers? PLOS ONE, March 2017; 12 (3): e0171903 DOI. The study provides details of sleep (or inactivity) in two wild, free-roaming African elephant matriarchs studied in their natural habitat with remote monitoring using an actiwatch subcutaneously implanted in the trunk, a standard elephant collar equipped with a GPS system and gyroscope, and a portable weather station. Download: 10.1371/journal.pone.0171903 Read more about the research, here:
Chase MJ, Schlossberg S, Griffin CR, Bouché PJC, Djene SW, Elkan PW, Ferreira S, Grossman F, Kohi EM, Landen K, Omondi P, Peltier A, Selier SAJ, Sutcliffe R. August 2016 Continent-wide survey reveals massive decline in African savannah elephants. PeerJ 4:e2354. African elephants (Loxodonta africana) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. https://doi.org/10.7717/peerj.2354 Read more about the GEC initiative at these links:
Schlossberg S., Chase M.J., Griffin C.R. Testing the accuracy of aerial surveys for large mammals: an experiment with African savanna elephants (Loxodonta africana). PLoS ONE. October 2016; 11: e0164904. Accurate counts of animals are critical for prioritizing conservation efforts. We used two approaches to assess the accuracy of aerial surveys for African savanna elephants (Loxodonta africana) in northern Botswana. First, we used double-observer sampling, in which two observers make observations on the same herds, to estimate detectability of elephants and determine what variables affect it. Second, we compared total counts, a complete survey of the entire study area, against sample counts, in which only a portion of the study area is sampled. https://www.researchgate.net/publication/309281395_Testing_the_Accuracy_of_Aerial_Surveys_for_Large_Mammals_An_Experiment_with_African_Savanna_Elephants_Loxodonta_africana
Adams, T., Chase, M.J., Rogers, T., Leggett, K. Taking the elephant out of the room and into the corridor: can urban corridors work? Oryx, May 2016. Urban wildlife corridors have been proposed as a potential mitigation tool to facilitate the passage of elephants through towns without causing conflict with urban communities. However, because such corridors are typically narrow and close to human development, wildlife (particularly large mammals) may be less likely to use them. We used remote-sensor camera traps and global positioning system collars to identify the movement patterns of African elephants Loxondonta africana through narrow, urban corridors in Botswana. http://journals.cambridge.org/action/displayFulltext?type=1&fid=10314518&jid=ORX&volumeId=-1&issueId=-1&aid=10314513
Miller, L., Chase, M.J., Hacker, C. E. A Comparison of Walking Rates between Wild and Zoo African Elephants. Journal of Applied Animal Welfare Science. March 2016. With increased scrutiny surrounding the welfare of elephants in zoological institutions, it is important to have empirical evidence on their current welfare status. If elephants are not receiving adequate exercise, it could lead to obesity, which can lead to many issues including acyclicity and potentially heart disease. The goal of the current study was to compare the walking rates of elephants in the wild versus elephants in zoos to determine if elephants are walking similar distances relative to their wild counterparts. http://www.ncbi.nlm.nih.gov/pubmed/26963741
Fynn, R., Chase, M.J., Roder, A., Functional habitat heterogeneity and large-herbivore seasonal habitat selection in northern Botswana. South African Journal of Wildlife Research, Aug 2015. Vol 23 Iss 4, pp 559-581. This study aimed to determine the functional seasonal attributes for herbivores of the major habitats and landscapes of the Savuti-Mababe-Linyanti ecosystem (SMLE) of northern Botswana and how various herbivore species responded to this heterogeneity. It was found that various herbivore species responded differently to functional heterogeneity across seasons and scales. http://www.bioone.org/doi/abs/10.3957/056.044.0103
Songhurst, A., Chase, M.J., Coulson, T. Using simulations of past and present elephant (Loxodonta africana) population numbers in the Okavango Delta Panhandle, Botswana to improve future population estimates. Wetlands Ecology and Management. Aug 2015. Vol 23 Issue 4, pp 583-602. An ability to reliably estimate population numbers, trends and densities of wildlife has a prominent role in conservation and management of wetlands. Our study reveals the usefulness of using simulations to test the reliability of survey data and plan more efficient surveys. These findings reinforce the need to address elephant management in the Okavango and surrounding wetland systems and call for the urgent consideration of management strategies such as fence realignments to affect the objectives of the Kavango Zambezi Transfrontier Conservation Area (KAZA TFCA) initiative, which will help relieve elephant population pressure. http://link.springer.com/article/10.1007/s11273-015-9440-4
McQualter, K. N., Chase, M.J., Fennessy, J. T., Mcleod, S. R., Leggett, K. Home Ranges, seasonal ranges and daily movements of giraffe (Giraffa camelopardalis giraffa) in northern Botswana. African Journal of Ecology. Vol 54 Issue 1. July 2015. Movement studies have been conducted on various giraffe subspecies across different ecological and management environments in Africa. However, prior to recent advancements in technology, studies were limited to identification methods relying on chance encounters of individuals, which can underestimate movements). Now, GPS satellite units enable remote monitoring of movements with the increased ability to collect more accurate and copious data sets. This study used GPS satellite collar technology to determine home ranges, seasonal ranges and daily movements of giraffe (G. c. giraffa) in northern Botswana. http://onlinelibrary.wiley.com/doi/10.1111/aje.12232/abstract
Naidoo, R., Chase, M.J., Beytell, P., du Preez, P., Landen, K., Stuart-Hill, G., Taylor, R., A newly-discovered wildlife migration in Namibia and Botswana is the longest in Africa. Oryx, Vol 50, Issue 1. May 2014. Migrations of most animal taxa are declining as a result of anthropogenic pressures and land-use transformation. Here, we document and characterize a previously unknown multi-country migration of Burchell’s zebra Equus quagga that is the longest of all recorded large mammal migrations in Africa. Regardless of the cause, the round-trip, straight-line migration distance of 500 km is greater than that covered by wildebeest during their well-known seasonal journey in the Serengeti ecosystem. It merits conservation attention, given the decline of large-scale ecological processes such as animal migrations. http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10083339&fileId=S0030605314000222
Roever, C.L., H.L. Beyer, M.J. Chase, and R.J. van Aarde. The pitfalls of ignoring behaviour when quantifying habitat selection, Diversity and Distributions Diversity and Distributions, 20, 322-333. Habitat selection is a behavioural mechanism by which animals attempt to maximize their inclusive fitness while balancing competing demands, such as finding food and rearing offspring while avoiding predation, in a heterogeneous and changing environment. Different habitat characteristics may be associated with each of these demands, implying that habitat selection varies depending on the behavioural motivations of the animal. Here, we investigate behaviour specific habitat selection in African elephants and discuss its implications for distribution modeling and conservation. http://onlinelibrary.wiley.com/doi/10.1111/ddi.12164/full
Roever, C.L., R.J. van Aarde, and M.J. Chase. Similarity in habitat preferences impedes human-elephant coexistence. 2013. Large conservation areas protect charismatic species and epitomize African savannahs, as do rural areas where people and wildlife live sympatrically but not always harmoniously. Incentives to include rural areas into conservation networks are lucrative and promise to improve conservation effectiveness. To mitigate this risk, elephants responded by selecting less suitable habitats. Consequently conservation strategies that promote human-wildlife coexistence may prove unsuccessful, particularly when resource competition leads to wildlife mortality. Conservation should ensure that people do not limit wildlife’s access to prime habitat. http://repository.up.ac.za/dspace/bitstream/handle/2263/28661/05chapter5.pdf?sequence=6&isAllowed=y
Roever, C.L., van Aarde, R.J., Chase, M.J. Incorporating mortality into habitat selection to identify secure and risky habitats for savannah elephants. Biological Conservation 164 (2013) 98–106. Empirical models of habitat selection are increasingly used to guide and inform habitat-based management plans for wildlife species. However, habitat selection does not necessarily equate to habitat quality particularly if selection is maladaptive, so incorporating measures of fitness into estimations of occurrence is necessary to increase model robustness. Here, we incorporated spatially explicit mortality events with the habitat selection of elephants to predict secure and risky habitats in northern Botswana. http://www.sciencedirect.com/science/article/pii/S0006320713001018
Havemann, C.P., Retief, T.A., Chase, M.J., Reisinger, R.R., Collins, K., deBruyn, P.J.N., Abundance of roan antelope in northern Botswana: comparisons of counting techniques. Monitoring and management of species depends on reliable population estimates. Although many techniques, including direct and indirect indices, have been used to count wildlife populations, it remains difficult and costly to acquire accurate abundance estimates of large cryptic mammals, especially when they live in dense vegetation. This study determined the abundance of roan antelope in the Linyanti concession in northern Botswana by comparing two direct abundance estimation techniques. https://www.sanparks.org/assets/docs/parks_kruger/conservation/scientific/noticeboard/science_network_meeting_2013/havemann-6March13.pdf
Chase, M.J., and Griffin, C.R.. Elephants of south-east Angola in war and peace: their decline, re-colonization and recent status. African Journal of Ecology, Vol 49 Issue 3, June 2011. Following the end of the civil war in 2002, our three aerial surveys of Luiana PR indicated that elephant numbers are increasing rapidly, from 366 in January 2004 to 1827 in November 2005, and expanding their range in the Reserve. Concurrently, elephants tagged with satellite collars in northern Botswana and the Caprivi Strip, Namibia, moved into Luiana PR. To facilitate re-colonization and conservation of elephants and other wildlife in Luiana PR, we recommend: (i) realignment of the veterinary fence on the Botswana–Namibia border; (ii) development of effective land use management and anti-poaching programmes; (iii) clearing of landmines; (iv) designation of the Reserve a national park; and (v) development of ecotourism and community conservation programmes.
Ferguson, K. and Hanks, J. Editors, Elephants and fencing conflicts in the GLTFCA and KAZA TFCA. In: Impacts: A review of the environmental, social and economic impacts of game and veterinary fencing in Africa with particular reference to the Great Limpopo and Kavango-Zambezi Transfrontier Conservation Areas (pp 173-180). 2010. http://www.wcs-ahead.org/gltfca.grants/grants.html or Download here
Cushman, S.A., Chase, M.J., and Griffin, C.R.. Mapping Landscape resistance to identify corridors and barriers for elephant movement in southern Africa. In S.A. Cushman and F. Huettmann (Ed.), Spatial Complexity, Informatics, and Wildlife Conservation, (pp. 349-367). Springer Japan. 2010 http://www.springerlink.com/content/n3p61l324nr65n75/
Chase, M.J. and Griffin, C. Elephants caught in the middle: Impacts of war, fences and people on elephant distribution and abundance in the Caprivi Strip, Namibia. African Journal of Ecology. 2009. We conducted wet [26 March–4 April 2003 (Apr03)] and dry [1–8 November 2005 (Nov05)] season aerial surveys of African elephants (Loxodonta africana Blumenbach) in the Caprivi Strip, Namibia to provide an updated status report on elephant numbers and distribution and assist with a historical analysis of elephant distribution and abundance in the Caprivi Strip.
Chase, M.J. and Griffin, C. Seasonal abundance and distribution of Elephants in Sioma Ngwezi National Park, southwest Zambia. Pachyderm No. 45 July 2008-June 2009. We conducted wet (January 2004) and dry (August 2004 and October 2005) season aerial surveys of African elephants (Loxodonta africana ) in Sioma Ngwezi National Park (NP) in southwest Zambia. Download PDF
Cushman, S.A., Chase, M.J., and Griffin, C. Elephants in space and time. Oikos, 109:331-341. 2005. In this paper we present an approach to analyzing the patterns of autocorrelation in animal movements that provides a detailed picture of seasonal variability in the scale and patterns of movement. Download PDF