Research Articles (Mammal Research Institute)

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A collection containing some of the full text peer-reviewed/ refereed articles published by researchers from the Mammal Research Institute

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Territoriality in adult male sub-Antarctic fur seals at Gough Island
Bester, Marthan Nieuwoudt; Rossouw, G.J. (Springer, 2025-03)
We analysed unpublished data on territory size and tenure in adult male sub-Antarctic fur seals Arctocephalus tropicalis recorded at Gough Island, Southern Ocean, during the 1975/76 austral summer breeding season. Adult males (n=15) remained on their territories for between 35–56 days (mean 45.4±6.7 days). Territory size during the peak breeding season was 21.9 m2 on average (n=42), but when partitioned by beach type, average territory sizes were 13.8 (n=9), 20.1 (n=17) and 28.3 m2 (n=16). Both territory tenure and territory size fall within the reported range of values established in fur seal species which hold territories on land as the predominant male reproductive strategy. We highlight numerous confounding factors that impact comparative studies which should be considered when interpreting theoretical, conceptual, and modelling approaches about territorial behaviour in otariids.
Seasonal occurrence and condition of leopard seals at an extralimital Sub‑Antarctic Island
Ross, Michael D.; Leitner, Monica; Oosthuizen, W. Chris; Bester, Marthan Nieuwoudt; Jordaan, Rowan Keith; Voysey, Michael D.; Conradie, Everhard C.; Dosi, Banele; Evans, Sean; Lloyd, Kyle J.; Monier, Zafar; Purdon, Jean; Reisinger, Ryan R.; Shihlomule, Yinhla Desmond; Van der Vyver, J.S. Fredrik; De Bruyn, P.J. Nico (Springer, 2025-06)
Leopard seals (Hydrurga leptonyx) occur mainly south of the Antarctic Polar Front, but immatures, in particular, seasonally move beyond this range during the austral winter and spring, typically under increased sea ice conditions. Extralimital occurrences of leopard seals can be observed at several sub-Antarctic islands where they haul out to rest. We present new records of leopard seal sightings at Marion Island, southern Indian Ocean, from 2006 to 2024 and discuss fluctuations in their seasonal and annual abundance (drawing on data collected since 1980) and body condition based on regular surveys. The eastern beaches at Marion Island were surveyed every 7–10 days while the western beaches were visited monthly. Observed leopard seals were photographed and given a body condition score based on the visibility of bony protrusions. From 2006 to 2024, we identified 35 presumed unique immature leopard seals between July and November, with a peak in September, all being immatures. Individuals to which we could assign body condition scores were either in good or excellent condition. This contrasted with the prevailing hypothesis that leopard seal body condition deteriorates with decreasing latitude. However, we could not determine whether this was because of an actual shift in body condition or because we used a different scoring system from other studies. We recommend adopting a standardised scoring system for visually estimating pinniped body condition and a global repository to monitor leopard seal haul-outs. As an apex predator, leopard seals may be important indicators in Antarctic and sub-Antarctic ecosystems, and monitoring changes in their distribution and body condition may indicate environmental and biological changes in these remote regions.
Monitoring of vagrant seals on mid-oceanic islands of the South Atlantic Ocean
Bester, Marthan Nieuwoudt; Somers, Michael J. (Springer, 2025-09)
Extra-limital sightings of seals breeding on the Antarctic pack- and fast ice and on sub-Antarctic and temperate islands of the South Atlantic Ocean are summarised. Particular life history events of four vagrant seal species that have turned up on Mid-Atlantic Ridge islands are presented, and the likely arrival of a further three vagrant seal species is speculated upon. The setting up and/or expansion of a recording system underpinned by an appropriate sighting protocol for vagrant seals in which citizen scientists can participate is advanced. Determination of whether range contractions/expansions of seals in the South Atlantic are taking place reflects on the status of the source population(s). Seal vagrancy may conceivably also be involved in the spread of viral diseases such as highly pathogenic avian influenza and rabies. Insights gained through extra-limital sightings of seals may assist with the establishment of conservation strategies.
Comparative life-cycle analyses reveal interacting climatic and biotic drivers of population responses to climate change
Ickin, Esin; Conquet, Eva; Abrahms, Briana; Albon , Steve D.; Blumstein, Daniel T.; Bond, Monica L.; Boersma , P. Dee; Clark-Wolf, Tyler J.; Clutton-Brock, Tim H.; Compagnoni , ldo; Dostálek, Tomáš; Evers, Sanne M.; Fichtel, Claudia; Gamelon, Marlène; García-Callejas, David; Griesser, Michael; Hansen , Brage B.; Jenouvrier, Stéphanie; Jerstadz, Kurt; Kappeler, Peter M.; Layton-Matthews, Kate; Lee, Derek E.; Lloret, Francisco; Loonen, Maarten J.J.E.; Malchow, Anne-Kathleen; Manser, Marta B.; Martin , Julien G.A.; Morales-González, Ana; Münzbergová, Zuzana; Nater, Chloé R.; Pillay, Neville; Quéroué, Maud; Røstadak, ac,ad, ai,al, am, a and , Ole W.; Sánchez-Mejía, Teresa; Schradin, Carsten; Sæther, Bernt-Erik; Ozgul, Arpat; Paniw, Maria (Oxford University Press, 2025-09)
Responses of natural populations to climate change are driven by how multiple climatic and biotic factors affect survival and reproduction, and ultimately shape population dynamics. Yet, despite substantial progress in synthesizing the sensitivity of populations to climatic variation, comparative studies still overlook such complex interactions among drivers that generate variation in population-level metrics. Here, we use a common framework to synthesize how the joint effects of climate and biotic drivers on different vital rates impact population change, using unique long-term data from 41 species, ranging from trees to primates. We show that simultaneous effects of multiple climatic drivers exacerbate population responses to climate change, especially for fast-lived species. However, accounting for density feedbacks under climate variation buffers the effects of climate change on population dynamics. In all species considered in our analyses, such interactions between climate and density had starkly different effects depending on the age, size, or life-cycle stage of individuals, regardless of the life history of species. Our work provides the first general framework to assess how covarying effects of climate and density across a wide range of population models can impact populations of plants and animals under climate change.
Development of an 11-oxoetiocholanolone mini-kit for the quantification of faecal glucocorticoid metabolites in various wildlife species
Edwards, KatieL.; Wheaton, Catharine J.; Brown, Janine L.; Dimovski, Alicia M.; Fanson, Kerry V.; Ganswindt, Andre; Ganswindt, Stefanie Birgit; Hagenah, Nicole; Keeley6, Tamara; Möstl, Erich; O’Hara, Bobbi; Penfold, LindaM.; Shablin, Samantha A.; Palme, Rupert (Oxford University Press, 2025-10)
As part of its mission to advance the field of wildlife endocrinology, the International Society of Wildlife Endocrinology aims to develop cost-effective antibodies and enzyme immunoassay kits that support research across a diverse range of species and sample matrices. To provide additional options for the quantification of faecal glucocorticoid metabolites (fGCMs), an antibody against 11-oxoetiocholanolone-17-carboxymethyl oxime (CMO) was generated in rabbits, and an enzyme immunoassay incorporating a horseradish peroxidase-conjugated label and 11-oxoetiocholanolone standard has been developed, designed for use with anti-rabbit IgG secondary antibody coated plates. This mini-kit was used to quantify glucocorticoid metabolites with a 5β-3α-ol-11-one structure in faecal extracts from 23 species: African and Asian elephants, Alpine chamois, American bison, Bengal tiger, blue wildebeest, blue-and-yellow macaw, brushtail possum, cape buffalo, fat-tailed dunnart, Florida manatee, ghost bat, giraffe, golden langur, Gould’s wattled bat, hippopotamus, Leadbeater’s possum, mandrill, okapi, roan antelope, samango monkey, short-beaked echidna, and western lowland gorilla. Pharmacological (adrenocorticotropic hormone challenge) and biological (inter-zoo translocation, wild capture, social disruption, illness/injury and veterinary intervention) challenges resulted in expected increases in fGCM concentrations, and in a subset of species, closely paralleled results from a previously established immunoassay against 11-oxoetiocholanolone-17-CMO. Two additional species tested, Krefft’s glider, which showed contradictory results on this assay compared to a previously validated enzyme immunoassay (EIA) and Ankole cow, where the magnitude increase post-event did not quite reach the 2-fold change criteria, highlight that differences in excreted faecal metabolites across species mean that no EIA will be suitable for all species. This assay provides a valuable new option for assessing adrenal activity across taxa using a group-specific antibody. Future studies should put similar emphasis on validation to determine optimal assay choice for measuring fGCMs in a variety of species.
Staying alive : individual behavioral variation influences survival, but not reproductive success, in female group-living ground squirrels
Warrington, Miyako H.; Van der Marel, Annemarie; Sojka, Jennifer; Shofstall, Krista J.; Waterman, Jane M. (Wiley, 2025-07)
Animals living in harsh or unpredictable environments adopt adaptive strategies to improve their fitness, with behavioral variation playing a key role in shaping individual outcomes. We examined whether between-individual variation in behavioral traits (personality) was associated with reproductive success and survival in female Cape ground squirrels (Xerus inauris). Using a 10-year dataset (2011–2021), we quantified behavioral expressions of the animal's response to trapping and handling (trap response, as a proxy for docility), trapping rate (trappability, for boldness) and the number of different trapping locations an animal was trapped at (trap diversity, for exploration) and examined their associations with (1) annual reproductive success, (2) lifetime reproductive success, (3) annual survival, and (4) on-site persistence (a proxy for lifespan). Response measures taken during transfer from the cage, handling by a human observer, and whether individuals ran or walked after release were moderately repeatable. Trappability was also repeatable, while trap diversity was not. Trap response and trappability were positively correlated with survival, but not reproductive success. Females that easily transferred from the trap to the handling bag (more docile) had higher annual survival, while those that ran after release had longer lifespans. Individuals trapped at a higher rate (bolder) had higher annual survival. The absence of a relationship between behavioral traits and reproductive success in females suggests that other factors, such as group dynamics, social interactions, and maternal effects, may be more influential in explaining the high reproductive skew in female reproductive success. Overall, our findings highlight the role of individual behavioral variation in shaping survival outcomes while emphasizing the need for further research into the mechanisms driving reproductive success in this species.
Multiyear Baleen endocrine profiles suggest a longer estimated gestation in southern right whales (Eubalaena australis)
Shuttleworth, Loraine; Ganswindt, Andre; Hunt, Kathleen E.; Fernandez Ajo, Alejandro; Pieterse, Estefan; Seakamela, S. Mduduzi; Schoeman, Chantel; Vermeulen, Els (Wiley, 2025-06)
Gestation length is a key reproductive parameter influencing fecundity, population growth rates, and the recovery potential of baleen whales. However, direct knowledge of the gestation length in these large mammals remains limited, primarily inferred from whaling and observational data. Over the past decade, southern right whales have experienced a decline in reproductive success, likely linked to climate-change-induced shifts in foraging conditions. Understanding the population-level consequences of these changes requires detailed longitudinal reproductive data. This study analyzes multiyear steroid hormone profiles in the baleen of adult female southern right whales stranded along the South African coast. Results show an extended hormonal pattern characterized by two peaks in progestogens between 20 and 25 months—suggesting putative pregnancies lasting substantially longer than previous estimates. Sharp estrogen peaks during periods of elevated progestogen phases may indicate hormonal regulation of myometrial contractions at birth. A positive correlation between progestogens and glucocorticoids suggests a role for glucocorticoids in pregnancy maintenance, while androgens provide limited insight into female reproduction in this species. These findings imply a longer-than-expected gestation period for southern right whales and potentially across the balaenid family. This has important implications for understanding the timing and location of conception, relevant for conservation management strategies. Multipopulation studies alongside individual sighting histories are recommended to refine our understanding of southern right whale reproduction further.
Monthly and diel acoustic occurrence of four Baleen whale species in South African waters
Shabangu, Fannie Welcome; Hlati, Kuhle; Van den Berg, Marcel A.; Lamont, Tarron; Kirkman, Stephen P. (Wiley, 2025-08)
Understanding of the spatio-temporal occurrence of cetaceans post the whaling era is essential for protecting and improving management strategies of these marine mammals. To determine the monthly and diel acoustic occurrence of four baleen whale species relative to environmental conditions off the west coast of South Africa, we collected passive acoustic monitoring data within Child's Bank marine protected area in January and May through October 2024 at various water depths. Burst tonal calls of the southern African Bryde's whale offshore population were detected in January and May through July with the highest occurrence in January. Humpback whale songs and southern right whale gunshot sounds were detected from May through October with high occurrence in September and with smaller modes in other months. Antarctic minke whale bioduck calls were also found in June through October, showing high occurrence in August through October. Calls from an unknown source with similar characteristics to Antarctic minke whale bioduck calls were present in May, July, and August with the highest occurrence in August. Diel acoustic occurrence of Bryde's, southern right, Antarctic minke, and minke-like whale calls indicated that these animals vocalised more during the day while humpback whales were more vocally active at night. Sea surface height and sea surface temperature, either separately or in combination, were the most important predictors of whale acoustic occurrence, highlighting the influence of environmental conditions on the distribution, habitat selection, and ecology of these whales. Overall, this study advances our understanding of the movement, occurrence, and behavioural patterns of several baleen whales relative to environmental conditions. It also provides the first description of the southern African Bryde's whale offshore population's call characteristics, which will be useful at guiding future studies to acoustically differentiate between it and the inshore population.
Interspecies haptic sociality : an observation of grooming between two mongoose species
Smith, Kyle; Hepplewhite, Malcolm; San, Emmanuel Do Linh; Somers, Michael J. (Wiley, 2025-06)
Meerkats (Suricata suricatta) and yellow mongooses (Cynictis penicillata) share many behavioural characteristics and are known to, on rare occasions, live in close association through displayed cooperative vigilance and shared burrow use. Here, we describe the first visual observation of tactile social behaviour through grooming between a meerkat and a yellow mongoose in the Rietvlei Nature Reserve, South Africa. We hypothesise that the close relationship between the two species in the reserve may be a response to a combination of phylogenetic ties, shared behavioural traits, and the population collapse of meerkats in the reserve that exposed a vacant social niche. This observation of interspecific sociality further extends our knowledge of cooperation and group augmentation among meerkats, yellow mongooses and carnivores in general.
Dietary plasticity of African clawless otters (Aonyx capensis) : an assessment of seasonal variation in prey availability
Burger, Marli; Ganswindt, Andre; Majelantle, Tshepiso L.; Scheun, Juan; Webster, Andrea B. (Wiley, 2025-07)
African clawless otters (Aonyx capensis) are opportunistic feeders with a broad dietary niche. Variation in their diet can be influenced by environmental and anthropogenic factors, which can affect seasonal and longitudinal prey availability. Flexibility in the diet allows African clawless otters to adapt to these changes and exploit novel prey items when available. Seasonal examination of otter spraints from three different locations across South Africa demonstrates that African clawless otters are able to shift from their preferred crab-based diet to a fish- or insect-based diet in response to environmental and anthropogenic drivers. Here we provide direct evidence of African clawless otters in terrestrial environments shifting to an insect-dominated diet when this resource is available. The dietary plasticity and response of this species to the shifts in available prey items may be an important factor for future consideration in conservation management of the species.
Stretching out : leopard home-range expansion in response to suppressed population density in a recovering post-war landscape
Briers-Louw, Willem D.; Kendon, Tamar A.; Hayes, Andres; Gaynor, David; Naude, Vincent (Wiley, 2025-10)
Large carnivores have profound regulatory effects on ecosystems and provide substantial socio‐economic benefits. However, mounting anthropogenic pressures are driving their global decline, threatening many species with extinction. Leopards, in particular, face challenges due to their wide‐ranging behavior, which exposes them to conflict with people and bycatch snaring, highlighting the importance of understanding their spatial ecology to develop more effective conservation strategies. This study aimed to estimate the home‐range size of female leopards (n = 4) within the Zambezi Delta, a unique mesic landscape undergoing broad‐scale ecological recovery in central Mozambique. Home‐range sizes ranged from 46 to 365 km2, falling within the range of global estimates. Surprisingly, these home‐range sizes, along with additional parameter estimates such as daily distance moved and home‐range overlap, were most comparable with those reported in arid environments. With female leopards appearing to occupy larger areas than theoretically required based on energetic needs, it is plausible that their spatial ecology is likely influenced by low population density. As the population recovers, we anticipate a re‐structuring of socio‐spatial dynamics driven by dispersal‐regulated processes, with females likely contracting their home‐range and partitioning them to their philopatric daughters. This study provides the first robust estimation of leopard home ranges in Mozambique and provides critical insights into the spatial ecology of leopards in a post‐war landscape. We recommend long‐term monitoring to track changes in population demographics and socio‐spatial dynamics as restoration efforts continue across central Mozambique.
A database on the historical and current occurrences of snakes in Eswatini
Monadjem, Ara; Boycott , Richard C.; Litscha-Koen, Thea; Kane, Adam; Dlamini, Wisdom M.; Mmema, Lindelwa; Strutton, Katharine L.; Hlophe , Zakhele; Padidar, Sara (Oxford University Press, 2025-07)
Snakes are among the most difficult terrestrial vertebrates to survey, resulting in poor distributional information on most species. This database comprises of 3812 records of 58 species of snakes in 37 genera reported from within the boundaries of Eswatini. The data were compiled from multiple sources including museum specimens, iNaturalist records, literature records, and snake rescue operations. For each specimen reported in the database, we provide the scientific name, latitude and longitude coordinates, and location. Most records also have an associated date. This comprehensive database will be useful to biodiversity experts, conservationists, medical practitioners, researchers, and snake enthusiasts, especially for mapping and modelling snake distributions in the country. To allow easy viewing of the distribution of snakes in the country, we provide an online visualization tool, which should allow a greater number of non-scientists to utilize this database.
Short communication: Elevated testosterone correlates with enhanced innate immune function in a cooperatively breeding rodent
Wallace, Kyra Mary Elizabeth; Venter, S.N. (Stephanus Nicolaas); Bennett, Nigel Charles; Hart, Daniel William (Elsevier, 2025-10)
In many vertebrates, elevated testosterone is believed to compromise the immune function, reflecting a trade-off between reproduction and survival. However, such trade-offs may potentially be relaxed in cooperative breeders, where social conflict and sexual selection are reduced. We investigated the relationship between testosterone, cortisol, and innate immunity in captive male Damaraland mole-rats (Fukomys damarensis), a eusocial rodent with minimal aggression-driven reproductive competition. Using microbial killing assays (MKAs) and white blood cell counts as proxies of immune function, we found that urinary testosterone concentration was positively correlated with immune strength. Males with higher urinary testosterone concentrations exhibited significantly greater antimicrobial capacity and elevated total white blood cell counts. However, urinary testosterone was unrelated to independent immune cell differentials. While, reproductive status, age, body mass, and urinary cortisol concentrations had a limited effect on any immune metric. These findings, while correlative, challenge traditional endocrine-immune trade-off models and infer that, in this species, testosterone may signal condition rather than impose immunosuppressive costs.
Unsustainable anthropogenic mortality threatens the long-term viability of lion populations in Mozambique
Almeida, Joao; Briers-Louw, Willem D.; Jorge, Agostinho; Begg, Colleen; Roodbol, Marnus; Bauer, Hans; Loveridge, Andrew; Wijers, Matthew; Slotow, Rob; Lindsey, Peter Andrew; Everatt, Kristoffer; Rosier, Holly; Nazerali, Sean; Roxburgh, Lizanne; Pereira, Hugo; Da Conceicao, Mercia; Araman, Armindo; Abrao, Osvaldo J.; Leslie, Alison J.; Steinbruch, Franziska; Naude, Vincent N.; Nicholson, Samantha K. (Public Library of Science, 2025-06)
Anthropogenic mortality is a pervasive threat to global biodiversity. African lions (Panthera leo) are particularly vulnerable to these threats due to their wide-ranging behaviour and substantial energetic requirements, which typically conflict with human activities, often resulting in population declines and even extirpations. Mozambique supports the 7th largest lion population in Africa, which is recovering from decades of warfare, while ongoing conflicts and broad-scale socio-economic fragility continue to threaten these populations. Moreover, there are concerns that Mozambique represents a regional hotspot for targeted poaching of lions which fuels a transnational illegal wildlife trade. This study aimed to quantify the longitudinal impact of anthropogenic mortality on lion populations in Mozambique. Using national population estimates and monitoring records, we performed forward simulation population viability modelling incorporating detection-dependent population trends and varying scales of anthropogenic mortality. Between 2010–2023, 326 incidents of anthropogenic mortality involving 426 lions were recorded. Bushmeat bycatch and targeted poaching for body parts were the greatest proximate causes of lion mortality (i.e., 53% of incidents), increasing significantly over time and acting as cryptic suppressors of regional population recovery, followed by legal trophy hunting (i.e., 33%), and retaliatory killing (i.e., 13%). Our findings suggest that resilience to anthropogenic threats is largely a function of lion population size as well as resource and management capacity. For instance, projections suggest that the lion population in Niassa Special Reserve will likely remain stable despite comparatively high levels of anthropogenic mortality, although further escalation may precipitate decline. Conversely, the lion population in Limpopo National Park is projected to become extirpated by 2030 without the buffering effect of its neighbouring source population in Kruger National Park. These unsustainable levels of anthropogenic mortality threaten the long-term viability of lion populations in Mozambique, requiring urgent national-level action and public-private partnerships to support site security, monitoring, and policy enforcement.
Underrepresentation of bats in Africa's protected areas
Montauban, Cecilia; Budinski, Ivana; Webala, Paul W.; Laverty, Theresa M.; Tanshi, Iroro; Torrent, Laura; Bakwo-Fils, Eric; Taylor, Peter J.; Kane, Adam; Monadjem, Ara (Wiley, 2025)
Biodiversity is severely threatened globally, with habitat loss and other human pressures accelerating species extinctions. Protected areas (PAs) are a critical conservation tool; however, their effectiveness in safeguarding many taxa, such as bats, remains unclear. Using georeferenced occurrence records and species distribution models (SDMs) for 263 sub-Saharan African bat species, we evaluated the coverage of bats in 7875 terrestrial PAs. Eighty-nine percent of bat species were recorded in at least 1 PA, yet 28 species, including 5 threatened and 15 data deficient species, were absent from all PAs. Species with large extents of occurrence were represented in more PAs, and fruit bats occupied significantly more PAs than clutter, edge, or open-air insectivorous foragers. The SDMs revealed high species richness in some undersurveyed areas, particularly in West and Central Africa and the Albertine Rift, emphasizing the need for targeted surveys. Our findings underscore critical data deficiencies related to bat conservation and stress the urgency of integrating bats into broader conservation planning. More surveys, enhanced data-sharing, and tailored conservation strategies are needed to improve bat representation in PAs and safeguard their ecological roles in Africa's biodiverse landscapes.
Neonatal antipredator tactics shape female movement patterns in large herbivores
Atmeh, Kamal; Bonenfant, Christophe; Gaillard, Jean-Michel; Garel, Mathieu; Hewison, A.J. Mark; Marchand, Pascal; Morellet, Nicolas; Anderwald, Pia; Buuveibaatar, Bayarbaatar; Beck, Jeffrey L.; Becker, Matthew S.; Van Beest, Floris M.; Berg, Jodi; Bergvall, Ulrika A.; Boone, Randall B.; Boyce, Mark S.; Chamaillé-Jammes, Simon; Chaval, Yannick; Buyanaa, Chimeddorj; Christianson, David; Ciuti, Simone; Cote, Steeve D.; Diefenbach, Duane R.; Droge, Egil; Du Toit, Johan T.; Dwinnell, Samantha; Fennessy, Julian; Filli, Flurin; Fortin, Daniel; Hart, Emma E.; Hayes, Matthew; Hebblewhite, Mark; Heim, Morten; Herfindal, Ivar; Heurich, Marco; Von Hoermann, Christian; Huggler, Katey; Jackson, Craig; Jakes, Andrew F.; Jones, Paul F.; Kaczensky, Petra; Kauffman, Matthew; Kjellander, Petter; LaSharr, Tayler; Loe, Leif Egil; May, Roel; McLoughlin, Philip; Meisingset, Erling L.; Merrill, Evelyn; Monteith, Kevin L.; Mueller, Thomas; Mysterud, Atle; Nandintsetseg, Dejid; Olson, Kirk; Payne, John; Pearson, Scott; Pedersen, Ashild Onvik; Ranglack, Dustin; Reinking, Adele K.; Rempfler, Thomas; Rice, Clifford G.; Roskaft, Eivin; Saether, Bernt-Erik; Said, Sonia; Santacreu, Hugo; Schmidt, Niels Martin; Smit, Daan; Stabach, Jared A.; St-Laurent, Martin-Hugues; Taillon, Joelle; Walter, W. David; White, Kevin; Peron, Guillaume; Loison, Anne (Nature Research, 2025-01)
Caring for newborn offspring hampers resource acquisition of mammalian females, curbing their ability to meet the high energy expenditure of early lactation. Newborns are particularly vulnerable, and, among the large herbivores, ungulates have evolved a continuum of neonatal antipredator tactics, ranging from immobile hider (such as roe deer fawns or impala calves) to highly mobile follower offspring (such as reindeer calves or chamois kids). How these tactics constrain female movements around parturition is unknown, particularly within the current context of increasing habitat fragmentation and earlier plant phenology caused by global warming. Here, using a comparative analysis across 54 populations of 23 species of large herbivores from 5 ungulate families (Bovidae, Cervidae, Equidae, Antilocapridae and Giraffidae), we show that mothers adjust their movements to variation in resource productivity and heterogeneity according to their offspring’s neonatal tactic. Mothers with hider offspring are unable to exploit environments where the variability of resources occurs at a broad scale, which might alter resource allocation compared with mothers with follower offspring. Our findings reveal that the overlooked neonatal tactic plays a key role for predicting how species are coping with environmental variation.
Interactions among nutrients govern the global grassland biomass-precipitation relationship
Fay, Philip A.; Gherardi, Laureano A.; Yahdjian, Laura; Adler, Peter B.; Bakker, Jonathan D.; Bharath, Siddharth; Borer, Elizabeth T.; Harpole, W. Stanley; Hersch-Green, Erika; Huxman, Travis E.; Macdougall, Andrew S.; Risch, Anita C.; Seabloom, Eric W.; Bagchi, Sumanta; Barrio, Isabel C.; Biederman, Lori; Buckley, Yvonne M.; Bugalho, Miguel N.; Caldeira, Maria C.; Catford, Jane A.; Chen, Qingqing; Cleland, Elsa E.; Collins, Scott L.; Daleo, Pedro; Dickman, Christopher R.; Donohue, Ian; Dupre, Mary E.; Eisenhauer, Nico; Eskelinen, Anu; Hagenah, Nicole; Hautier, Yann; Heckman, Robert W.; Jonsdottir, Ingibjoerg S.; Knops, Johannes M.H.; Laungani, Ramesh; Martina, Jason P.; Mcculley, Rebecca L.; Morgan, John W.; Venterink, Harry Olde; Peri, Pablo L.; Power, Sally A.; Raynaud, Xavier; Ren, Zhengwei; Roscher, Christiane; Smith, Melinda D.; Spohn, Marie; Stevens, Carly J.; Tedder, Michelle J.; Virtanen, Risto; Wardle, Glenda M.; Wheeler, George R. (National Academy of Sciences, 2025-04-11)
Ecosystems are experiencing changing global patterns of mean annual precipitation (MAP) and enrichment with multiple nutrients that potentially colimit plant biomass production. In grasslands, mean aboveground plant biomass is closely related to MAP, but how this relationship changes after enrichment with multiple nutrients remains unclear. We hypothesized the global biomass–MAP relationship becomes steeper with an increasing number of added nutrients, with increases in steepness corresponding to the form of interaction among added nutrients and with increased mediation by changes in plant community diversity. We measured aboveground plant biomass production and species diversity in 71 grasslands on six continents representing the global span of grassland MAP, diversity, management, and soils. We fertilized all sites with nitrogen, phosphorus, and potassium with micronutrients in all combinations to identify which nutrients limited biomass at each site. As hypothesized, fertilizing with one, two, or three nutrients progressively steepened the global biomass–MAP relationship. The magnitude of the increase in steepness corresponded to whether sites were not limited by nitrogen or phosphorus, were limited by either one, or were colimited by both in additive, or synergistic forms. Unexpectedly, we found only weak evidence for mediation of biomass–MAP relationships by plant community diversity because relationships of species richness, evenness, and beta diversity to MAP and to biomass were weak or opposing. Site-level properties including baseline biomass production, soils, and management explained little variation in biomass–MAP relationships. These findings reveal multiple nutrient colimitation as a defining feature of the global grassland biomass–MAP relationship. SIGNIFICANCE Understanding how multiple interacting nutrients regulate the global relationship between mean annual precipitation and aboveground biomass is crucial for forecasting how ecosystem functioning will be altered by ongoing global changes. We fertilized with nitrogen, phosphorus, and potassium plus micronutrients in all combinations in 71 grasslands representing a global precipitation gradient. The grassland biomass–precipitation relationship became steeper with an increasing number of added nutrients. Increases in steepness corresponded to the form of interaction among added nitrogen and phosphorus. We found weak evidence that variation in plant species diversity mediated changes in the biomass–precipitation relationship. Multiple nutrient colimitation, particularly by nitrogen and phosphorus, is a defining feature of grassland biomass–precipitation relationships, and crucial to predicting grassland responses to global change.
Cold dogs : sperm freezing, artificial insemination & non-invasive monitoring tools to facilitate a hybrid conservation management approach for endangered African wild dogs
Paris, Damien Boyd Bertrand Paul; Riddell, Pia; Joone, Carolynne Jane; De la Rey, Morne; Ganswindt, Andre; Paris, Monique Christina Johanna (Elsevier, 2024)
Given the ongoing fragmentation and decline of suitable habitat coupled with recurring disease outbreaks and pack eradications, a major rethink is required to manage the long-term genetic diversity of the endangered African wild dog. Competing financial demands in developing countries mean that conservation strategies need to yield the biggest genetic gains for the smallest economic cost. As such, we propose the development of a hybrid conservation approach to the metapopulation management of African wild dogs, which augments assisted dispersal and natural breeding initiatives with genetic gains afforded by sperm banking and artificial insemination. We discuss how such an approach would address current challenges faced by the species in the context of its unique social biology and how this could integrate with existing conservation management interventions. Moreover, during a period spanning nearly 20 years, we have developed many of the supporting reproductive technologies required to maximise genetic diversity of African wild dogs, in addition to a suite of non-invasive management tools to quantify, monitor and manipulate behaviour, vocalisations, hormones for reproductive function and responses to stressors, as well as immune function to improve the social cohesion, health and reproduction of packs.
Superstable lipid vacuoles endow cartilage with its shape and biomechanics
Ramos, Raul; Pham, Kim T.; Prince, Richard C.; Leiser-Miller, Leith B.; Prasad, Maneeshi S.; Wang, Xiaojie; Nordberg, Rachel C.; Bielajew, Benjamin J.; Hu, Jerry C.; Yamaga, Kosuke; Oh, Ji Won; Peng, Tao; Datta, Rupsa; Astrowskaja, Aksana; Almet, Axel A.; Burns, John T.; Liu, Yuchen; Guerrero-Juarez, Christian Fernando; Tran, Bryant Q.; Chu, Yi-Lin; Nguyen, Anh M.; Hsi, Tsai-Ching; Lim, Norman T. -L.; Schoeniger, Sandra; Liu, Ruiqi; Pai, Yun-Ling; Vadivel, Chella K.; Ingleby, Sandy; McKechnie, Andrew E.; Van Breukelen, Frank; Hoehn, Kyle L.; Rasweiler, John J.; Kohara, Michinori; Loughry, William J.; Weldy, Scott H.; Cosper, Raymond; Yang, Chao-Chun; Lin, Sung-Jan; Cooper, Kimberly L.; Santana, Sharlene E.; Bradley, Jeffrey E.; Kiebish, Michael A.; Digman, Michelle; James, David E.; Merrill, Amy E.; Nie, Qing; Schilling, Thomas F.; Astrowski, Aliaksandr A.; Potma, Eric O.; Garcia-Castro, Martin I.; Athanasiou, Kyriacos A.; Behringer, Richard R.; Plikus, Maksim V. (American Association for the Advancement of Science, 2025-01)
ABSTRACT Conventionally, the size, shape, and biomechanics of cartilages are determined by their voluminous extracellular matrix. By contrast, we found that multiple murine cartilages consist of lipid-filled cells called lipochondrocytes. Despite resembling adipocytes, lipochondrocytes were molecularly distinct and produced lipids exclusively through de novo lipogenesis. Consequently, lipochondrocytes grew uniform lipid droplets that resisted systemic lipid surges and did not enlarge upon obesity. Lipochondrocytes also lacked lipid mobilization factors, which enabled exceptional vacuole stability and protected cartilage from shrinking upon starvation. Lipid droplets modulated lipocartilage biomechanics by decreasing the tissue’s stiffness, strength, and resilience. Lipochondrocytes were found in multiple mammals, including humans, but not in nonmammalian tetrapods. Thus, analogous to bubble wrap, superstable lipid vacuoles confer skeletal tissue with cartilage-like properties without “packing foam–like” extracellular matrix. STRUCTURED ABSTRACT INTRODUCTION : Vertebrates have a complex endoskeleton that consists of cartilage and ossifying bones. The biomechanics of the collagen-rich extracellular matrix in cartilage underlie its physical integrity. Additionally, during embryonic development, vertebrates also form the notochord, an endoskeletal tissue that affords animal bodies with mechanical support through hydrostatics. The notochord maintains its shape and stiffness owing to its large cells, whose aqueous vacuoles resist compression. Remnants of the notochord in most vertebrates became the nucleus pulposus, a ball-like structure at the center of intervertebral disks. RATIONALE : In this study, we noticed adipocyte-like cells featuring a giant lipid vacuole present throughout mouse ear cartilage. Yet, unlike adipocytes, these cells did not label with adipose-specific genetic markers. We chose to characterize this form of cartilage, called lipocartilage, which we found in vital anatomical structures of the nose, ear, larynx, and chest, and to establish whether its biomechanical properties depend on intracellular vacuoles. RESULTS : We found that precursor cells for lipocartilage expressed transcriptional factors and extracellular matrix genes shared with the progenitors of “conventional” cartilage. During terminal differentiation, lipocartilage precursor cells activated lipid metabolism genes, including de novo lipogenesis enzymes that convert glucose to fatty acids. Lipocartilage formation depended on de novo lipogenesis to synthesize lipid vacuoles, and unlike adipocytes, its cells could not take up additional fatty acids from the circulation. Furthermore, compared with adipocytes, mature lipocartilage cells lacked enzymes needed to breakdown stored lipids, resulting in metabolically “locked” vacuoles. In fact, when adult mice were challenged with either caloric restriction or a high-fat diet, their external ears and the lipid vacuoles contained within them did not change in size. This was in contrast to adipose tissues, which readily emptied or filled their lipid vacuoles, respectively. Beyond rodents, we identified lipocartilage in phylogenetically diverse mammals, including in the ears of echolocating bats, where it becomes particularly intricate. Abundant lipid droplets also form in human cartilage cells grown in vitro from embryonic stem cells. CONCLUSION : We postulate that lipocartilage is a distinct type of vacuolated skeletal tissue that has evolved in mammals and is similar in form and function to vacuolated notochord. Lipocartilage attains and maintains its size and shape by adapting a distinct lipid metabolism program that enables the formation of superstable lipid vacuoles. Skeletal elements made of lipocartilage commonly acquire complex, micropatterned shapes, such as in elaborately shaped bat ears. Our lipid washout assays further suggest that vacuoles are critically required for lipocartilage biomechanics, calling for in-depth studies on the structure-function relationship between intracellular vacuoles versus extracellular matrix in skeletal tissues. Regenerative medicine strategies for embryonic stem cell–derived human cartilage can use lipid vacuoles as a natural biomarker that distinguishes differentiated cells from pluripotent progenitors. EDITOR'S SUMMARY Cartilage is considered to be a mostly cell-free tissue made of copious extracellular matrix. Ramos et al. describe the embryonic development, gene expression, biochemistry, physiology, and biomechanics of lipid-filled cartilage in mice (see the Perspective by Hermosilla Aguayo and Selleri). This “fatty cartilage” forms from lipochondrocytes found in the face, neck, and chest of phylogenetically diverse mammals. It can adopt intricately patterned shapes and has life-long stability and elastic properties because of its large lipid vacuoles within numerous long-lived cells having little extracellular matrix. These findings hold promise for advancing our understanding of form-to-function relationships in skeletal tissues. —Stella M. Hurtley
The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses
Clements , Hayley S.; San, Emmanuel Do Linh; Hempson, Gareth; Linden , Birthe; Maritz, Bryan; Monadjem, Ara; Reynolds , Chevonne; Siebert, Frances; Stevens, Nicola; Biggs , Reinette; De Vos, Alta; Blanchard , Ryan; Child , Matthew; Esler , Karen J.; Hamann, Maike; Loft, Ty; Reyers, Belinda; Selomane, Odirilwe; Skowno, Andrew L.; Tshoke, Tshegofatso; Abdoulaye, Diarrassouba; Aebischer, Thierry; Aguirre-Gutiérrez, Jesús; Alexander, Graham J.; Ali, Abdullahi H.; Allan, David G.; Amoako , Esther E.; Angedakin, Samuel; Aruna, Edward; Avenant , Nico L.; Badjedjea, Gabriel; Bakayoko, Adama; Bamba-kaya, Abraham; Bates, Michael F.; Bates, Paul J.J.; Belmain , Steven R.; Bennitt , Emily; Bradley, James; Brewster, Chris A.; Brown, Michael B.; Brown , Michelle; Bryja, Josef; Butynski, Thomas M.; Carvalho, Filipe; Channing, Alan; Chapman, Colin A.; Cohen, Callan; Cords , Marina; Cramer, Jennifer D.; Cronk , Nadine; Cunneyworth, Pamela M.K.; Dalerum, Fredrik; Danquah, Emmanuel; Davies-Mostert, Harriet T.; De Blocq , Andrew D.; De Jong , Yvonne A.; Demos , Terrence C.; Denys , Christiane; Djagoun, Chabi A.M.S.; Doherty-Bone , Thomas M.; Drouilly, Marine; Du Toit, Johan T.; Ehlers Smith, David A.; Ehlers Smith, Yvette C.; Eiseb , Seth J.; Fashing, Peter J.; Ferguson, Adam W.; Fernández-García, José M.; Finckh, Manfred; Fischer, Claude; Gandiwa, Edson; Gaubert, Philippe; Gaugris , Jerome Y.; Gibbs, Dalton J.; Gilchrist , Jason S.; Gil- Sánchez , Jose M.; Githitho, Anthony N.; Goodman, Peter S.; Granjon , Laurent; Grobler, J. Paul; Gumbi, Bonginkosi C.; Gvozdik, Vaclav; Harvey, James; Hauptfleisch, Morgan; Hayder, Firas; Hema, Emmanuel M.; Herbst, Marna; Houngbédji, Mariano; Huntley, Brian J.; Hutterer, Rainer; Ivande, Samuel T.; Jackson, Kate; Jongsma, Gregory F.M.; Juste , Javier; Kadjo, Blaise; Kaleme, Prince K.; Kamugisha, Edwin; Kaplin, Beth A.; Kato, Humphrey N.; Kiffner , Christian; Kimuyu , Duncan M.; Kityo, Robert M.; Kouamé, N’goran G.; Kouete T, Marcel; Le Roux, Aliza; Lee, Alan T.K.; Lötter, Mervyn C.; Lykke , Anne Mette; MacFadyen, Duncan N.; Macharia, Gacheru P.; Madikiza , Zimkitha J.K.; Mahlaba, Themb'alilahlwa A.M.; Mallon, David; Mamba, Mnqobi L.; Mande, Claude; Marchant, Rob A.; Maritz, Robin A.; Markotter, Wanda; McIntyre , Trevor; Measey , John; Mekonnen , Addisu; Meller, Paulina; Melville, Haemish I.; Mganga, Kevin Z.; Mills, Michael G.L.; Minnie , Liaan; Missoup, Alain Didier; Mohammad, Abubakr; Moinde, Nancy N.; Moise , Bakwo Fils E.; Monterroso , Pedro; Moore , Jennifer F.; Musila, Simon; Nago , Sedjro Gilles A.; Namoto, Maganizo W.; Niang, Fatimata; Nicolas , Violaine; Nkenku, Jerry B.; Nkrumah, Evans E.; Nono, Gonwouo L.; Norbert, Mulavwa M.; Nowak , Katarzyna; Obitte , Benneth C.; Okoni-Williams, Arnold D.; Onongo, Jonathan; O ’Riain , M. Justin; Osinubi , Samuel T.; Parker, Daniel M.; Parrini , Francesca; Peel, Mike J.S.; Penner, Johannes P; Pietersen, Darren William; Plumptre , Andrew J.; Ponsonby, Damian W.; Porembski, Stefan; Power, R. John; Radloff , Frans G.T.; Rambau, Ramugondo V.; Ramesh, Tharmalingam; Richards , Leigh R.; Rödel, Mark-Oliver; Rollinson, Dominic P.; Rovero, Francesco; Saleh, Mostafa A.; Schmiedel, Ute; Schoeman , M. Corrie; Scholte, Paul; Serfass, Thomas L.; Shapiro, Julie Teresa; Shema , Sidney; Siebert, Stefan J.; Slingsby, Jasper A.; Sliwa, Alexander; Smit-Robinson , Hanneline A.; Sogbohossou, Etotepe A.; Somers, Michael J.; Spawls, Stephen; Streicher, Jarryd P.; Swanepoel, Lourens; Tanshi, Iroro; Taylor, Peter J.; Taylor, William A.; Te Beest, Mariska; Telfer, Paul T.; Thompson , Dave I.; Tobi , Elie; Tolley, Krystal A.; Turner, Andrew A.; Twine, Wayne; Van Cakenberghe , Victor; Van de Perre, Frederik; Van der Merwe , Helga; Van Niekerk, Chris J.G.; Van Wyk, Pieter C.V.; Venter, Jan A.; Verburgt, Luke; Veron , Geraldine; Vetter , Susanne; Vorontsova , Maria S.; Wagner , Thomas C.; Webala, Paul W.; Weber, Natalie; Weier, Sina M.; White , Paula A.; Whitecross, Melissa A.; Wigley, Benjamin J.; Willems, Frank J.; Winterbach, Christiaan W.; Woodhouse, Galena M. (Nature Research, 2024-02-12)
Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems.

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