Parental Risk-Taking at Natural Northern Bobwhite Nests

2017 ◽  
Vol 10 (2) ◽  
pp. 69-75
Author(s):  
Yu Xu ◽  
Susan N. Ellis-Felege ◽  
John P. Carroll
Keyword(s):  
Risk Taking ◽  
Didelphis Virginiana ◽  
Lynx Rufus ◽  
Northern Bobwhites ◽  
Trade Offs ◽  
Future Reproduction ◽  
Incubating Birds ◽  
Study Sites ◽  
Southern Georgia ◽  
Predator Community

Parental risk-taking at the nest is critical to examining the trade-offs between current and future reproduction. Using Northern Bobwhites ( Colinus virginianus) at camera-monitored nests in the natural environment, we examined how parental and offspring characteristics, predator community, and predator type affected flush distance of incubating birds to approaching predators. During 1999–2006, we monitored 118 predation interactions at nests at two pairs of study sites in southern Georgia and northern Florida, USA where mesomammalian predators were experimentally reduced or not reduced. The results showed that incubating parent birds allowed closer approaches by predators that typically only consumed eggs ( e.g. Nine-banded Armadillos Dasypus novemcinctus, Virginia Opossums Didelphis virginiana, and snakes) than by predators that could harm the adults (including Bobcats Lynx rufus and Raccoons Procyon lotor) prior to flushing from the nest. Our data did not support the hypotheses that parent-offspring characteristics and predator community affect parental risk-taking at the nest. Our findings suggest that parent birds incorporate information about predator identity over parental and offspring characteristics or predator community into anti-predator decisions at the nest in systems with high predation risk.

Mate availability facilitates cannibalistic behaviour in a nest brooding fish: effects of timing during the brood cycle

Behaviour ◽  
2011 ◽  
Vol 148 (2) ◽  
pp. 247-264 ◽  
Author(s):  
Masanori Kohda ◽  
Nobuhiro Ohnishi ◽  
Noboru Okuda ◽  
Tomohiro Takeyama ◽  
Omar Myint
Keyword(s):  
Laboratory Experiments ◽  
Gravid Female ◽  
Theoretical Models ◽  
Filial Cannibalism ◽  
Mate Availability ◽  
Stimulus Female ◽  
Trade Offs ◽  
Future Reproduction ◽  
Cannibalistic Behaviour ◽  
The Subject

AbstractFilial cannibalism, eating one's own viable offspring, is accepted as an adaptive response to trade-offs between current and future reproduction. Theoretical models predict that high mate availability may induce more filial cannibalism, but this prediction is rarely tested. To examine this prediction, we performed laboratory experiments using the nest breeding goby Rhinogobius flumineus. Subject males were allowed to mate with a gravid female and care for the broods. A separate gravid female housed in a small cage (stimulus-female) was shown to the subject males at one of three different points during the brood cycle: prior to spawning, within 1 day after spawning and 1 week after spawning. Empty cages were shown as a control. Males that were shown the stimulus-female before spawning cannibalised more eggs than control males. In contrast, males that were shown the stimulus-females after spawning cannibalised as few eggs as control males did. Additionally, males that were shown the stimulus-female prior to spawning did not court females more intensively than other males. Thus, we suggest that the presence of an additional mate, rather than energy expenditure associated with courtship directed toward an additional mate, can facilitate males to cannibalise their eggs.

Farmer-Prioritized Climate-Smart Agriculture Technologies

2020 ◽  
pp. 423-445
Author(s):  
Caroline Mwongera ◽  
Chris M. Mwungu ◽  
Mercy Lungaho ◽  
Steve Twomlow
Keyword(s):  
Climate Change ◽  
Sustainable Development ◽  
Sustainable Development Goals ◽  
Smallholder Farmers ◽  
The Sustainable Development ◽  
Trade Offs ◽  
Development Goals ◽  
Smart Agriculture ◽  
Study Sites ◽  
Context Specific

Climate-smart agriculture (CSA) focuses on productivity, climate-change adaptation, and mitigation, and the potential for developing resilient food production systems that lead to food and income security. Lately, several frameworks and tools have been developed to prioritize context-specific CSA technologies and assess the potential impacts of selected options. This study applied a mixed-method approach, the climate-smart agriculture rapid appraisal (CSA-RA) tool, to evaluate farmers’ preferred CSA technologies and to show how they link to the sustainable development goals (SDGs). The chapter examines prioritized CSA options across diverse study sites. The authors find that the prioritized options align with the food security and livelihood needs of smallholder farmers, and relate to multiple sustainable development goals. Specifically, CSA technologies contribute to SDG1 (end poverty), SDG2 (end hunger and promote sustainable agriculture), SDG13 (combating climate change), and SDG15 (life on land). Limited awareness on the benefits of agriculture technologies and the diversity of outcomes desired by stakeholders’ present challenges and trade-offs for achieving the SDGs. The CSA-RA provides a methodological approach linking locally relevant indicators to the SDG targets.

Carnivore persistence in fragmented habitats in urban southern California

2003 ◽  
Vol 9 (2) ◽  
pp. 144 ◽  
Author(s):  
Lourraine A. Tigas ◽  
Dirk H. Van Vuren ◽  
Raymond M. Sauvajot
Keyword(s):  
Native Species ◽  
Southern California ◽  
Didelphis Virginiana ◽  
Lynx Rufus ◽  
Urban Habitat ◽  
Secondary Importance ◽  
Carnivore Species ◽  
Close Proximity ◽  
Remote Camera ◽  
Total Species

We investigated the responses of carnivores to habitat fragmentation in urban southern California. We used scat, track, and remote camera surveys to determine presence and residence of carnivores on habitat fragments of various sizes (4.4-561.0 ha) and degrees of isolation (10-750 m). Fragment area explained a significant portion of the variation in all four measures of species richness (total species present, native species present, total species resident, and native species resident). Isolation was of secondary importance and was significant only for species presence. We suggest that fewer carnivore species at smaller or more isolated fragments resulted from foraging decisions based on lower food reward in smaller fragments and greater movement costs for more distant fragments. Carnivore species responded differentially to fragmentation. Bobcats Lynx rufus were fragmentation-sensitive and apparently required large fragments, thus they may be useful as focal species for conservation planning. In contrast, Coyotes Canis latrans were more fragmentation-tolerant and, along with smaller species such as Northern Raccoons Procyon lotor, Striped Skunks Mephitis mephitis, and Virginia Opossums Didelphis virginiana, can persist in smaller fragments. Our results suggest that most of the common carnivores can persist in fragmented urban habitat, provided that fragments are sufficiently large and in close proximity.

scholarly journals Financial opportunity costs and deaths among close kin are independently associated with reproductive timing in a contemporary high-income society

2020 ◽  
Vol 287 (1919) ◽  
pp. 20192478
Author(s):  
V. Berg ◽  
D. W. Lawson ◽  
A. Rotkirch
Keyword(s):  
High Income ◽  
Reproductive Timing ◽  
Economic Costs ◽  
Wage Penalty ◽  
Income Loss ◽  
Trade Offs ◽  
Career Opportunities ◽  
Evolutionary Demography ◽  
Future Reproduction ◽  
Demographic Theory

Evolutionary demography predicts that variation in reproductive timing stems from socio-ecologically contingent trade-offs between current and future reproduction. In contemporary high-income societies, the costs and benefits of current reproduction are likely to vary by socioeconomic status (SES). Two influential hypotheses, focusing on the parenthood ‘wage penalty’, and responses to local mortality have separately been proposed to influence the timing of parenthood. Economic costs of reproduction (i.e. income loss) are hypothesized to delay fertility, especially among high childhood SES individuals who experience greater opportunities to build capital through advantageous education and career opportunities. On the other hand, relatively low childhood SES individuals experience higher mortality risk, which may favour earlier reproduction. Here, we examine both hypotheses with a representative register-based, multigenerational dataset from contemporary Finland ( N = 47 678). Consistent with each hypothesis, the predicted financial cost of early parenthood was smaller, and mortality among close kin was higher for individuals with lower childhood SES. Within the same dataset, lower predicted adulthood income and more kin deaths were also independently associated with earlier parenthood. Our results provide a robust demonstration of how economic costs and mortality relate to reproductive timing. We discuss the implications of our findings for demographic theory and public policy.

scholarly journals Experimental evidence for adaptive personalities in a wild passerine bird

2012 ◽  
Vol 279 (1749) ◽  
pp. 4885-4892 ◽  
Author(s):  
Marion Nicolaus ◽  
Joost M. Tinbergen ◽  
Karen M. Bouwman ◽  
Stephanie P. M. Michler ◽  
Richard Ubels ◽  
...  
Keyword(s):  
Risk Taking ◽  
Survival Probability ◽  
Parus Major ◽  
Passerine Bird ◽  
Recent Theory ◽  
Risky Behaviour ◽  
Environment Effects ◽  
Trade Offs ◽  
Increase Risk

Individuals of the same species differ consistently in risky actions. Such ‘animal personality’ variation is intriguing because behavioural flexibility is often assumed to be the norm. Recent theory predicts that between-individual differences in propensity to take risks should evolve if individuals differ in future fitness expectations: individuals with high long-term fitness expectations (i.e. that have much to lose) should behave consistently more cautious than individuals with lower expectations. Consequently, any manipulation of future fitness expectations should result in within-individual changes in risky behaviour in the direction predicted by this adaptive theory. We tested this prediction and confirmed experimentally that individuals indeed adjust their ‘exploration behaviour’, a proxy for risk-taking behaviour, to their future fitness expectations. We show for wild great tits ( Parus major ) that individuals with experimentally decreased survival probability become faster explorers (i.e. increase risk-taking behaviour) compared to individuals with increased survival probability. We also show, using quantitative genetics approaches, that non-genetic effects (i.e. permanent environment effects) underpin adaptive personality variation in this species. This study thereby confirms a key prediction of adaptive personality theory based on life-history trade-offs, and implies that selection may indeed favour the evolution of personalities in situations where individuals differ in future fitness expectations.

scholarly journals Social learning spreads knowledge about dangerous humans among American crows

2011 ◽  
Vol 279 (1728) ◽  
pp. 499-508 ◽  
Author(s):  
Heather N. Cornell ◽  
John M. Marzluff ◽  
Shannon Pecoraro
Keyword(s):  
Social Learning ◽  
Individual Learning ◽  
Accurate Information ◽  
Facial Features ◽  
Sources Of Information ◽  
Corvus Brachyrhynchos ◽  
Trade Offs ◽  
American Crows ◽  
Place Of Origin ◽  
Study Sites

Individuals face evolutionary trade-offs between the acquisition of costly but accurate information gained firsthand and the use of inexpensive but possibly less reliable social information. American crows ( Corvus brachyrhynchos ) use both sources of information to learn the facial features of a dangerous person. We exposed wild crows to a novel ‘dangerous face’ by wearing a unique mask as we trapped, banded and released 7–15 birds at five study sites near Seattle, WA, USA. An immediate scolding response to the dangerous mask after trapping by previously captured crows demonstrates individual learning, while an immediate response by crows that were not captured probably represents conditioning to the trapping scene by the mob of birds that assembled during the capture. Later recognition of dangerous masks by lone crows that were never captured is consistent with horizontal social learning. Independent scolding by young crows, whose parents had conditioned them to scold the dangerous mask, demonstrates vertical social learning. Crows that directly experienced trapping later discriminated among dangerous and neutral masks more precisely than did crows that learned through social means. Learning enabled scolding to double in frequency and spread at least 1.2 km from the place of origin over a 5 year period at one site.

scholarly journals Leaders’ ambidexterity traits

2019 ◽  
Author(s):  
Montserrat Boronat-Navarro ◽  
Alexandra García-Joerger
Keyword(s):  
Risk Taking ◽  
Current Knowledge ◽  
Present Knowledge ◽  
Organizational Ambidexterity ◽  
Exploration And Exploitation ◽  
Top Managers ◽  
Trade Offs ◽  
Sustained Performance ◽  
Balance Trade ◽  
Organizational Innovations

The ability of companies to develop simultaneously innovations that exploit their   current knowledge, while exploring new opportunities that go beyond their present knowledge is recognized as organizational ambidexterity and essential in the achievement of sustained performance above the average of the industry. The concept of ambidexterity, includes exploration and exploitation. Exploration requires search, discovery, experimentation, risk-taking and innovation, while exploitation consists of behavioral patterns characterized by refinement, implementation, efficiency, production and selection. Top managers are crucial to balance trade-offs among these competing objectives regarding exploration and exploitation and to reduce the organization’s tendency to focus only in one of them. Top managers act as a leaders in the process of exploiting existing competencies while also exploring new opportunities. In this study we are going to review the literature to extract the characteristics of ambidextrous leaders capable to cope with these tensions, in order to achieve organizational innovations.

scholarly journals Experimentally induced antipredator responses are mediated by social and environmental factors

2019 ◽  
Vol 30 (4) ◽  
pp. 986-992 ◽  
Author(s):  
Frank Groenewoud ◽  
Sjouke A Kingma ◽  
Kat Bebbington ◽  
David S Richardson ◽  
Jan Komdeur
Keyword(s):  
Predation Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Ecological Factors ◽  
Antipredator Defense ◽  
Trade Offs ◽  
Future Reproduction ◽  
Female Investment ◽  
Predator Model ◽  
Nest Predator

AbstractNest predation is a common cause of reproductive failure for many bird species, and various antipredator defense behaviors have evolved to reduce the risk of nest predation. However, trade-offs between current reproductive duties and future reproduction often limit the parent’s ability to respond to nest predation risk. Individual responses to experimentally increased nest predation risk can give insights into these trade-offs. Here, we investigate whether social and ecological factors affect individual responses to predation risk by experimentally manipulating the risk of nest predation using taxidermic mounts in the cooperative breeding Seychelles warbler (Acrocephalus sechellensis). Our results show that dominant females, but not males, alarm called more often when they confront a nest predator model alone than when they do so with a partner, and that individuals that confront a predator together attacked more than those that did so alone. Dominant males increased their antipredator defense by spending more time nest guarding after a presentation with a nest predator, compared with a nonpredator control, but no such effect was found for females, who did not increase the time spent incubating. In contrast to incubation by females, nest guarding responses by dominant males depended on the presence of other group members and food availability. These results suggest that while female investment in incubation is always high and not dependent on social and ecological conditions, males have a lower initial investment, which allows them to respond to sudden changes in nest predation risk.

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