scholarly journals Developmental changes in foraging-predator avoidance trade-offs in larval lumpfish Cyclopterus lumpus

1991 ◽  
Vol 76 ◽  
pp. 53-60 ◽  
Author(s):  
PJ Williams ◽  
JA Brown
Behaviour ◽  
1993 ◽  
Vol 126 (1-2) ◽  
pp. 125-135 ◽  
Author(s):  
Carin Magnhagen ◽  
Elisabet Forsgren

AbstractThe effects of predation risk on the reproductive behaviour of male and female sand gobies, Pomatoschistus minutus, were investigated in two separate aquarium studies. In the presence of a predator (cod, Gadus morhua), males decreased their courtship activity while females did not alter their level of activity. In the second study, there was no difference between treatments (with and without predator) in the time from when a female was presented to a male with a nest until spawning took place or in the amount of eggs laid. However, pre-spawning behaviour differed between the two treatments. When the cod was in sight, both males and females burrowed in the sand more often. In the absence of a predator, pairs spent longer together in the nest before spawning started, and females also inspected the nest alone, which never happened during predator presence. Hence, both sexes make trade-offs between predator avoidance and behaviours associated with mating. Females, however, seem to take higher risks during the courtship phase in order to find a partner compared to males.


2021 ◽  
Author(s):  
Stuart Oldham ◽  
Ben D. Fulcher ◽  
Kevin M Aquino ◽  
Aurina M Arnatkeviciute ◽  
Casey Paquola ◽  
...  

The complex connectivity of nervous systems is thought to have been shaped by competitive selection pressures to minimize wiring costs and support adaptive function. Accordingly, recent modeling work indicates that stochastic processes, shaped by putative trade-offs between the cost and value of each connection, can successfully reproduce many topological properties of macroscale human connectomes measured with diffusion magnetic resonance imaging. Here, we derive a new formalism with the aim to more accurately capture the competing pressures of wiring cost minimization and topological complexity. We further show that model performance can be improved by accounting for developmental changes in brain geometry and associated wiring costs, and by using inter-regional transcriptional or microstructural similarity rather than topological wiring-rules. However, all models struggled to capture topologies spatial embedding. Our findings highlight an important role for genetics in shaping macroscale brain connectivity and indicate that stochastic models offer an incomplete account of connectome organization.


2014 ◽  
Vol 60 (3) ◽  
pp. 323-332 ◽  
Author(s):  
Chris K. Elvidge ◽  
Indar Ramnarine ◽  
Grant E. Brown

Abstract In response to acute predation threats, prey may sacrifice foraging opportunities in favour of increased predator avoidance. Under conditions of high or frequent predation risk, such trade-offs may lead to reduced fitness. Here, we test the prediction that prey reduce the costs associated with lost opportunities following acute predation threats by exhibiting short-term compensatory foraging responses. Under semi-natural conditions, we exposed female guppies Poecilia reticulate from high and low predation risk sites to one of three levels of acute predation threat (high, intermediate or low concentrations of conspecific alarm cues). Our results confirm previous reports, demonstrating that guppies from a high predation site were consistently ‘bolder’ (shorter escape latencies) and exhibited graded threat-sensitive responses to different simulated threat levels while those from the low predation site were ‘shyer’ and exhibited non-graded responses. Most importantly, we found that when guppies from low predation sites resumed foraging, they did so at rates significantly lower than baseline rates. However, guppies from high predation sites resumed foraging either at rates equal to baseline (in response to low or intermediate risk stimuli) or significantly increased relative to baseline rates (in response to high risk stimuli). Together, these results highlight a complex compensatory behavioral mechanism that may allow prey to reduce the long-term costs associated with predator avoidance.


1999 ◽  
Vol 42 (6) ◽  
pp. 1400-1413 ◽  
Author(s):  
Kathryn J. Kohnert ◽  
Elizabeth Bates ◽  
Arturo E. Hernandez

The present study investigated developmental changes in lexical production skills in early sequential bilinguals, in both Spanish (L1) and English (L2), exploring the effects of age, years of experience, and basic-level cognitive processing (specifically the ability to resist interference) within a timed picture-naming task. To assess resistance to interference, naming was compared in low competition (blocked-single language) vs. high competition (mixed-alternating language) conditions. Participants were 100 individuals, 20 at each of 5 different age levels (5–7, 8–10, 11–13, 14–16, & young adults). All had learned Spanish as a first language in the home, with formal English experience beginning at 5 years. Gains were made in both languages across age. However, there was a developmental crossover from Spanish dominance in the youngest children, through a period of relatively balanced Spanish and English skills in middle childhood, culminating in a clear pattern of English dominance among adolescents and young adults. Although all groups experienced a greater slowing of response times in the mixed-language condition relative to the blocked-language condition, developmental changes in the pattern of speed-accuracy trade-offs in the mixed condition can be interpreted to reflect a change in the ability to resist cognitive interference during word production.


2014 ◽  
Vol 33 (1) ◽  
pp. 124-133 ◽  
Author(s):  
Stephanie A. Hernandez ◽  
Barbara L. Peckarsky

2007 ◽  
Vol 115 (1) ◽  
pp. 37-40
Author(s):  
Hideyuki Okuzumi ◽  
Mitsuru Kokubun ◽  
Kyoko Shimada

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