scholarly journals Oil Palm Cultivation Critically Affects Sociality in an Endangered Malaysian Primate

2020 ◽  
Author(s):  
Anna Holzner ◽  
Krishna Balasubramaniam ◽  
Nadine Ruppert ◽  
Anja Widdig
Keyword(s):  
Oil Palm ◽  
Infant Development ◽  
Group Living ◽  
Anthropogenic Landscapes ◽  
Individual Fitness ◽  
Natural Behaviour ◽  
Social Network Structure ◽  
Animal Populations ◽  
Species Adaptability ◽  
And Shifts

Abstract Human-induced habitat alterations globally threaten animal populations, often evoking complex behavioural responses in wildlife. This may be particularly dramatic when negatively affecting social behaviour, which fundamentally determines individual fitness and offspring survival in group-living animals. Here, we provide first evidence for critical behavioural modifications in sociality of Southern pig-tailed macaques visiting Malaysian oil palm plantations in search of food. Specifically, we found significant reductions of positive social interactions, an increase of aggression and shifts in the macaques' social network structure, with the central positions of high-ranking adult females and immatures being passed to low-ranking individuals, likely resulting from socio-ecological risks posed by plantations. Deviations from natural behaviour also affected the smallest but crucial social units within groups, mother-infant pairs, with increased maternal protectiveness at plantations. We suggest that although primates can persist in human-altered habitats, their ability to adapt comes with a trade-off for their natural sociality, potentially hampering infant development and individual survival. Studies like ours remain critical for understanding species’ adaptability to anthropogenic landscapes, which may ultimately contribute to facilitating their coexistence with humans and preserving biodiversity.

scholarly journals Oil palm cultivation critically affects sociality in a threatened Malaysian primate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Holzner ◽  
Krishna N. Balasubramaniam ◽  
Brigitte M. Weiß ◽  
Nadine Ruppert ◽  
Anja Widdig
Keyword(s):  
Social Interactions ◽  
Oil Palm ◽  
Group Living ◽  
Anthropogenic Landscapes ◽  
Habitat Alterations ◽  
Individual Fitness ◽  
Social Network Structure ◽  
Animal Populations ◽  
Survival Studies ◽  
Species Adaptability

AbstractHuman-induced habitat alterations globally threaten animal populations, often evoking complex behavioural responses in wildlife. This may be particularly dramatic when negatively affecting social behaviour, which fundamentally determines individual fitness and offspring survival in group-living animals. Here, we provide first evidence for significant behavioural modifications in sociality of southern pig-tailed macaques visiting Malaysian oil palm plantations in search of food despite elevated predation risk. Specifically, we found critical reductions of key positive social interactions but higher rates of aggression in the plantation interior compared to the plantation edge (i.e. plantation areas bordering the forest) and the forest. At the plantation edge, affiliation even increased compared to the forest, while central positions in the macaques' social network structure shifted from high-ranking adult females and immatures to low-ranking individuals. Further, plantations also affected mother–infant relationships, with macaque mothers being more protective in the open plantation environment. We suggest that although primates can temporarily persist in human-altered habitats, their ability to permanently adapt requires the presence of close-by forest and comes with a trade-off in sociality, potentially hampering individual fitness and infant survival. Studies like ours remain critical for understanding species’ adaptability to anthropogenic landscapes, which may ultimately contribute to facilitating their coexistence with humans and preserving biodiversity.

scholarly journals Family feud: permanent group splitting in a highly philopatric mammal, the killer whale (Orcinus orca)

2021 ◽  
Vol 75 (3) ◽  
Author(s):  
Eva H. Stredulinsky ◽  
Chris T. Darimont ◽  
Lance Barrett-Lennard ◽  
Graeme M. Ellis ◽  
John K. B. Ford
Keyword(s):  
Killer Whale ◽  
Group Structure ◽  
Group Living ◽  
Orcinus Orca ◽  
Learning Approaches ◽  
Killer Whales ◽  
Internal Factors ◽  
Individual Fitness ◽  
Leadership Experience

Abstract For animals that tend to remain with their natal group rather than individually disperse, group sizes may become too large to benefit individual fitness. In such cases, group splitting (or fission) allows philopatric animals to form more optimal group sizes without sacrificing all familiar social relationships. Although permanent group splitting is observed in many mammals, it occurs relatively infrequently. Here, we use combined generalized modeling and machine learning approaches to provide a comprehensive examination of group splitting in a population of killer whales (Orcinus orca) that occurred over three decades. Fission occurred both along and across maternal lines, where animals dispersed in parallel with their closest maternal kin. Group splitting was more common: (1) in larger natal groups, (2) when the common maternal ancestor was no longer alive, and (3) among groups with greater substructuring. The death of a matriarch did not appear to immediately trigger splitting. Our data suggest intragroup competition for food, leadership experience and kinship are important factors that influence group splitting in this population. Our approach provides a foundation for future studies to examine the dynamics and consequences of matrilineal fission in killer whales and other taxa. Significance statement Group living among mammals often involves long-term social affiliation, strengthened by kinship and cooperative behaviours. As such, changes in group membership may have significant consequences for individuals’ fitness and a population’s genetic structure. Permanent group splitting is a complex and relatively rare phenomenon that has yet to be examined in detail in killer whales. In the context of a growing population, in which offspring of both sexes remain with their mothers for life, we provide the first in-depth examination of group splitting in killer whales, where splitting occurs both along and across maternal lines. We also undertake the first comprehensive assessment of how killer whale intragroup cohesion is influenced by both external and internal factors, including group structure, population and group demography, and resource abundance.

scholarly journals Social fluidity mobilizes contagion in human and animal populations

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ewan Colman ◽  
Vittoria Colizza ◽  
Ephraim M Hanks ◽  
David P Hughes ◽  
Shweta Bansal
Keyword(s):  
Social Bonds ◽  
Group Living ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Frequency Dependent ◽  
Density Dependent ◽  
Gregarious Behavior ◽  
Animal Populations ◽  
Group Members ◽  
Social Fluidity

Humans and other group-living animals tend to distribute their social effort disproportionately. Individuals predominantly interact with a small number of close companions while maintaining weaker social bonds with less familiar group members. By incorporating this behavior into a mathematical model, we find that a single parameter, which we refer to as social fluidity, controls the rate of social mixing within the group. Large values of social fluidity correspond to gregarious behavior, whereas small values signify the existence of persistent bonds between individuals. We compare the social fluidity of 13 species by applying the model to empirical human and animal social interaction data. To investigate how social behavior influences the likelihood of an epidemic outbreak, we derive an analytical expression of the relationship between social fluidity and the basic reproductive number of an infectious disease. For species that form more stable social bonds, the model describes frequency-dependent transmission that is sensitive to changes in social fluidity. As social fluidity increases, animal-disease systems become increasingly density-dependent. Finally, we demonstrate that social fluidity is a stronger predictor of disease outcomes than both group size and connectivity, and it provides an integrated framework for both density-dependent and frequency-dependent transmission.

The importance of superior-quality wildlife habitats

2004 ◽  
Vol 80 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Ian D Thompson
Keyword(s):  
Habitat Selection ◽  
Habitat Quality ◽  
Population Level ◽  
Individual Fitness ◽  
Animal Populations ◽  
Cumulative Change ◽  
Few Data ◽  
Managed Landscapes ◽  
The Relationship

While animals may use many habitat types, relatively few are preferred and fewer yet are superior in quality (referring to individual fitness as the measure of quality). Historical reduction in habitat quality for some wildlife species has occurred such that we may now have limited reference to original superior-quality habitats. As time passes, managers may be unaware that superior habitats are slowly disappearing and that the slow but cumulative change is significant to a species at the population level. The perception of superior-quality habitat also changes with each successive generation of managers based on their experiences. This paper raises the concern that retrospective work may often be required to determine past forest habitats and associated animal populations to avoid the risk of falling into a trap of not recognizing ever-declining habitat quality through time and relegating animals to what is in fact much poorer quality habitat than those to which they are actually best adapted. Further, the relationship between relative abundance and habitat quality may often be uncertain owing to maladaptive habitat selection by animals, inappropriate survey timing or interannual population differences. While we have begun to appreciate aspects of habitat selection for many forest species, few data are yet available that relate selected habitats to fitness of individual animals. Hence, while we may have models to predict habitat use, considerable research remains to be done to be able to predict long-term sustainability of species in managed landscapes. Key words: habitat quality, forest management, sustainability, biodiversity

scholarly journals The Goldilocks effect: female geladas in mid-sized groups have higher fitness

2021 ◽  
Vol 288 (1952) ◽  
pp. 20210820
Author(s):  
Elizabeth Tinsley Johnson ◽  
Jacob A. Feder ◽  
Thore J. Bergman ◽  
Amy Lu ◽  
Noah Snyder-Mackler ◽  
...  
Keyword(s):  
Group Size ◽  
Reproductive Performance ◽  
Demographic Data ◽  
Group Living ◽  
Cost Benefit ◽  
Individual Fitness ◽  
Cost Benefit Ratio ◽  
Reproductive Rates ◽  
The Cost ◽  
The Relationship

The cost–benefit ratio of group living is thought to vary with group size: individuals in ‘optimally sized’ groups should have higher fitness than individuals in groups that are either too large or too small. However, the relationship between group size and individual fitness has been difficult to establish for long-lived species where the number of groups studied is typically quite low. Here, we present evidence for optimal group size that maximizes female fitness in a population of geladas ( Theropithecus gelada ). Drawing on 14 years of demographic data, we found that females in small groups experienced the highest death rates, while females in mid-sized groups exhibited the highest reproductive performance. This group size effect on female reproductive performance was largely explained by variation in infant mortality (and, in particular, by infanticide from immigrant males) but not by variation in reproductive rates. Taken together, females in mid-sized groups are projected to attain optimal fitness due to conspecific infanticide and, potentially, predation. Our findings provide insight into how and why group size shapes fitness in long-lived species.

scholarly journals The Ecological and Immunological Relationships Between Salmonella and Tuatara

2021 ◽  
Author(s):  
◽  
Danielle Mary Rose Lea Middleton
Keyword(s):  
New Zealand ◽  
Immune Responses ◽  
Microbial Activity ◽  
Pathogenic Bacteria ◽  
Temporal Dynamics ◽  
Cross Reactivity ◽  
Antibody Recognition ◽  
Individual Fitness ◽  
Animal Populations

<p>The transmission and expression of disease in wild animal populations is a complex interaction of host, pathogen and environmental factors. The individual fitness of a host may be negatively impacted by pathogenic bacteria in a number of ways including increased predation risk and reduced survival and reproductive output. Salmonellosis is an important zoonotic disease resulting in significant morbidity and mortality in populations of wild reptiles, birds and mammals throughout the world, and herpetofaunal species have often been implicated as shedders and transmitters of Salmonella globally. To better understand the unique threats to New Zealand native wildlife, I investigated spatio-temporal dynamics of Salmonella in an island ecosystem, and selected one species, tuatara (Sphenodon punctatus) (an endemic New Zealand reptile), for in-depth immunological analyses. I collected cloacal swabs and faecal samples from native wildlife on Stephens Island repeatedly between October 2009 and October 2011. While Salmonella was isolated from 6.5% of native skinks and 8% of the soil samples, intestinal carriage of Salmonella was not detected in the more than 600 cloacal swabs collected from wild tuatara, despite these tuatara living in close proximity to Salmonella-positive skinks or soil. In context, the lack of Salmonella detected in tuatara in this and other studies raises the question of whether tuatara are innately resistant to Salmonella. To test this hypothesis I examined aspects of innate and adaptive immune responses in tuatara serum. Immune measurements included in vitro anti-microbial activity of serum and antibody recognition of bacterial antigens. Serum was tested against three closely related enteric pathogens, including Salmonella, in order to establish the importance of cross-reactivity in the strength of immune responses observed. I found that tuatara possess antibodies which recognise Salmonella antigens by Western blot and flow cytometry. I also determined that the anti-microbial activity of tuatara serum was approximately 6-fold higher than donkey or mouse sera, but showed similar activity to other reptilian species tested. These findings are the first report of both environmentally-induced anti-Salmonella antibodies and anti-microbial activity in tuatara serum. Taken together, these studies investigating the distribution and seasonality of Salmonella within the environment and evaluating anti-Salmonella immune responses in tuatara will help to inform decisions about disease screening and animal movements to maintain the health of native fauna.</p>

scholarly journals The Ecological and Immunological Relationships Between Salmonella and Tuatara

2021 ◽  
Author(s):  
◽  
Danielle Mary Rose Lea Middleton
Keyword(s):  
New Zealand ◽  
Immune Responses ◽  
Microbial Activity ◽  
Pathogenic Bacteria ◽  
Temporal Dynamics ◽  
Cross Reactivity ◽  
Antibody Recognition ◽  
Individual Fitness ◽  
Animal Populations

<p>The transmission and expression of disease in wild animal populations is a complex interaction of host, pathogen and environmental factors. The individual fitness of a host may be negatively impacted by pathogenic bacteria in a number of ways including increased predation risk and reduced survival and reproductive output. Salmonellosis is an important zoonotic disease resulting in significant morbidity and mortality in populations of wild reptiles, birds and mammals throughout the world, and herpetofaunal species have often been implicated as shedders and transmitters of Salmonella globally. To better understand the unique threats to New Zealand native wildlife, I investigated spatio-temporal dynamics of Salmonella in an island ecosystem, and selected one species, tuatara (Sphenodon punctatus) (an endemic New Zealand reptile), for in-depth immunological analyses. I collected cloacal swabs and faecal samples from native wildlife on Stephens Island repeatedly between October 2009 and October 2011. While Salmonella was isolated from 6.5% of native skinks and 8% of the soil samples, intestinal carriage of Salmonella was not detected in the more than 600 cloacal swabs collected from wild tuatara, despite these tuatara living in close proximity to Salmonella-positive skinks or soil. In context, the lack of Salmonella detected in tuatara in this and other studies raises the question of whether tuatara are innately resistant to Salmonella. To test this hypothesis I examined aspects of innate and adaptive immune responses in tuatara serum. Immune measurements included in vitro anti-microbial activity of serum and antibody recognition of bacterial antigens. Serum was tested against three closely related enteric pathogens, including Salmonella, in order to establish the importance of cross-reactivity in the strength of immune responses observed. I found that tuatara possess antibodies which recognise Salmonella antigens by Western blot and flow cytometry. I also determined that the anti-microbial activity of tuatara serum was approximately 6-fold higher than donkey or mouse sera, but showed similar activity to other reptilian species tested. These findings are the first report of both environmentally-induced anti-Salmonella antibodies and anti-microbial activity in tuatara serum. Taken together, these studies investigating the distribution and seasonality of Salmonella within the environment and evaluating anti-Salmonella immune responses in tuatara will help to inform decisions about disease screening and animal movements to maintain the health of native fauna.</p>

scholarly journals Role of sociality in the response of killer whales to an additive mortality event

2019 ◽  
pp. 201817174 ◽  
Author(s):  
Marine Busson ◽  
Matthieu Authier ◽  
Christophe Barbraud ◽  
Paul Tixier ◽  
Ryan R. Reisinger ◽  
...  
Keyword(s):  
Social Structure ◽  
Social Groups ◽  
Group Living ◽  
Foraging Success ◽  
Killer Whales ◽  
Negative Effects ◽  
Mortality Event ◽  
Individual Fitness ◽  
Fishing Vessels ◽  
Additive Mortality

In highly social top predators, group living is an ecological strategy that enhances individual fitness, primarily through increased foraging success. Additive mortality events across multiple social groups in populations may affect the social structure, and therefore the fitness, of surviving individuals. This hypothesis was examined in a killer whale (Orcinus orca) population that experienced a 7-y period of severe additive mortality due to lethal interactions with illegal fishing vessels. Using both social and demographic analyses conducted on a unique long-term dataset encompassing periods before, during, and after this event, results indicated a decrease in both the number and the mean strength of associations of surviving individuals during the additive mortality period. A positive significant correlation between association strength and apparent survival suggested that the fitness of surviving individuals was impacted by the additive mortality event. After this event, individuals responded to the loss of relatives in their social groups by associating with a greater number of other social groups, likely to maintain a functional group size that maximized their foraging success. However, these associations were loose; individuals did not reassociate in highly stable social groups, and their survival remained low years after the mortality event. These findings demonstrate how the disruption of social structure in killer whales may lead to prolonged negative effects of demographic stress beyond an additive mortality event. More importantly, this study shows that sociality has a key role in the resilience of populations to human-induced mortality; this has major implications for the conservation of highly social and long-lived species.

scholarly journals Triple Flat-Type Inductive-Based Oil Palm Fruit Maturity Sensor

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2496 ◽  
Author(s):  
Nor Aliteh ◽  
Norhisam Misron ◽  
Ishak Aris ◽  
Roslina Mohd Sidek ◽  
Kunihisa Tashiro ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Oil Palm ◽  
Fixed Number ◽  
Fresh Fruit Bunch ◽  
Palm Fruit ◽  
Flat Type ◽  
Fruit Maturity ◽  
The Mean ◽  
Palm Fruits ◽  
And Shifts

This paper aims to study a triple flat-type air coil inductive sensor that can identify two maturity stages of oil palm fruits, ripe and unripe, based on the resonance frequency and fruitlet capacitance changes. There are two types of triple structure that have been tested, namely Triple I and II. Triple I is a triple series coil with a fixed number of turns (n = 200) with different length, and Triple II is a coil with fixed length (l = 5 mm) and a different number of turns. The peak comparison between Triple I and II is using the coefficient of variation cv, which is defined as the ratio of the standard deviation to the mean to express the precision and repeatability of data. As the fruit ripens, the resonance frequency peaks from an inductance–frequency curve and shifts closer to the peak curve of the air, and the fruitlet capacitance decreases. The coefficient of the variation of the inductive oil palm fruit sensor shows that Triple I is smaller and more consistent in comparison with Triple II, for both resonance frequency and fruitlet capacitance. The development of this sensor proves the capability of an inductive element such as a coil, to be used as a sensor so as to determine the ripeness of the oil palm fresh fruit bunch sample.

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