Age-Related Differences in Ruddy Turnstone Foraging and Aggressive Behavior

The Auk ◽  
1978 ◽  
Vol 95 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Sarah Groves

Abstract The foraging behavior of fall migrant Ruddy Turnstones was studied on the Massachusetts coast on 2 different substrates, barnacle-covered rocks and sand and weed-littered flats. Foraging rates differed significantly between the 2 substrates. On each substrate the foraging and success rates of adults and juveniles differed significantly while the frequencies of success were similar for both age-classes. The observed differences in foraging rates of adults and juveniles may be due to the degree of refinement of foraging techniques. Experience in searching for and handling prey may be a primary factor accounting for these differences, and foraging performance probably improves with age and experience. Alternatively, the differences may be due to the presence of inefficient juveniles that do not survive to adulthood. Both adults and juveniles in the tail-depressed posture were dominant in aggressive interactions much more frequently than birds in the tail-level posture. In mixed flocks of foraging adult and juvenile turnstones, the four possible types of aggressive interactions occurred nonrandomly. Adult over juvenile interactions occurred more frequently than expected, and juvenile over adult interactions were never seen. A tentative explanation of this phenomenon may be that juveniles misinterpret or respond ambivalently to messages conveyed behaviorally by adults and thus become especially vulnerable to aggression by adults. The transiency of migrants made it unfeasible to evaluate the persistence of this nonrandom aggression.

2020 ◽  
Vol 636 ◽  
pp. 189-205
Author(s):  
A Lescroël ◽  
PO’B Lyver ◽  
D Jongsomjit ◽  
S Veloz ◽  
KM Dugger ◽  
...  

Inter-individual differences in demographic traits of iteroparous species can arise through learning and maturation, as well as from permanent differences in individual ‘quality’ and sex-specific constraints. As the ability to acquire energy determines the resources an individual can allocate to reproduction and self-maintenance, foraging behavior is a key trait to study to better understand the mechanisms underlying these differences. So far, most seabird studies have focused on the effect of maturation and learning processes on foraging performance, while only a few have included measures of individual quality. Here, we investigated the effects of age, breeding experience, sex, and individual breeding quality on the foraging behavior and location of 83 known-age Adélie penguins at Cape Bird, Ross Sea, Antarctica. Over a 2 yr period, we showed that (1) high-quality birds dived deeper than lower quality ones, apparently catching a higher number of prey per dive and targeting different foraging locations; (2) females performed longer foraging trips and a higher number of dives compared to males; (3) there were no significant age-related differences in foraging behavior; and (4) breeding experience had a weak influence on foraging behavior. We suggest that high-quality individuals have higher physiological ability, enabling them to dive deeper and forage more effectively. Further inquiry should focus on determining the physiological differences among penguins of different quality.


2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Manuela L. Brandão ◽  
Gisele Colognesi ◽  
Marcela C. Bolognesi ◽  
Roselene S. Costa-Ferreira ◽  
Thaís B. Carvalho ◽  
...  

ABSTRACT Changes in water temperature may affect the aggressive behavior of aquatic organisms, such as fish, either by changing some physiological mechanisms or by increasing the probability of encounters between individuals as a result of variation in their swimming activity. In our study, we evaluated the influence of increasing and decreasing temperature on the aggressive behavior of the Neotropical cichlid fish Cichlasoma paranaense. Firstly, we tested the critical thermal maximum (CTMax) tolerated by this species. Then, we tested the effect of decreasing or increasing the water temperature in 6o C (starting at 27° C) on the aggressive interactions of fish under isolation or housed in groups. We found a CTMax value of 39° C for C. paranaense. We also observe that a 6° C decrease in water temperature lowers swimming activity and aggressive interactions in both isolated and group-housed fish, as expected. On the other hand, the increase in temperature had no effect on the fish’s aggressive behavior, neither for isolated nor for grouped fish. We concluded that C. paranaense shows high tolerance to elevated temperatures and, in turn, it does not affect aggressive behavior. Nevertheless, we cannot dismiss possible effects of elevated temperatures on aggressive interactions over longer periods.


2018 ◽  
Vol 48 (4) ◽  
pp. 304-310 ◽  
Author(s):  
Thaís Billalba CARVALHO ◽  
Ellen Cristina Monteiro de SOUZA ◽  
Jaquelinne PINHEIRO-DA-SILVA ◽  
Marle Angélica VILLACORTA-CORREA

ABSTRACT Brycon amazonicus is a native Amazonian fish that is important for aquaculture in South America. Larval mortality is high in this species in intensive breeding systems due to aggressiveness among larvae. The present study investigated experimentally the effects of body size heterogeneity on the aggressive behavior and survival of B. amazonicus during the early stages of larval development. Two treatments (larvae groups with homogeneous and heterogeneous body size) were evaluated throughout early larval stages tested at six time points: 12, 24, 36, 48, 60 and 72 hours after hatching (HAH). Two experiments quantified, respectively, aggressive interactions and mortality rates among larvae at each time point. The frequency of aggressive interactions exhibited by the less aggressive larvae in each replicate was higher in the homogeneous size treatment. Aggressiveness was higher at 12 HAH, decreasing thereafter, and increasing again at 72 HAH. The mortality rate significantly increased with the larval stage, and was higher in the homogeneous than in the heterogeneous sized groups. Our results showed that aggressiveness in B. amazonicus larvae is affected by size variability and larval development stage. This knowledge about larval behavior is important to develop measures to improve larval health and survival in intensive production systems for this species.


The Auk ◽  
1987 ◽  
Vol 104 (4) ◽  
pp. 647-653 ◽  
Author(s):  
Patricia Parker Rabenold

Abstract In a 5-yr study of a partially marked population of Black Vultures (Coragyps atratus) in North Carolina, turnover among marked birds in a large winter roost averaged 34% each night. Roost attendance and areawide resighting rates differed among age classes; juveniles remained site faithful while young adults ranged far, and adults were intermediate in movement. Local breeders were more consistent in year-round attendance at roosts near their nest sites than were other marked adults using these roosts, and local breeders were likewise overrepresented on initial days at baited feeding sites. During aggressive interactions at roosts and at food, adults won over young birds and juveniles lost to older birds. Breeding adults won more fights close to their nest sites than farther away. Winners of fights at roosts were more likely to be present on subsequent evenings than were losers. The results suggest that food-finding adults, primarily local breeders, can to some extent control local roost membership by means of aggressive interactions in roosts. Successful foragers can reduce the costs of being followed and sharing food by limiting the number and identity of potential followers through aggression.


2018 ◽  
Vol 64 (No. 9) ◽  
pp. 379-386 ◽  
Author(s):  
Deligöz Ayşe ◽  
Bayar Esra ◽  
Genç Musa ◽  
Karatepe Yasin ◽  
Kirdar Erol ◽  
...  

Variations in the photosynthetic pigments and total carbohydrate contents of needles of different age classes (current-year, 1-year-old, 2-year-old and 3-year-old) of Pinus nigra subsp. pallasiana (Lambert) Holmboe trees in a young natural stand were investigated during the growing season. In current-year needles, total carbohydrate content was lower during June and July when the needle growth continued than in older age classes, but it was similar to other age classes in the months of August to October. Seasonal patterns of variations in total carbohydrate content were almost similar in 1-, 2-, and 3-year-old needles. Chlorophyll and carotenoid contents increased from May to June, remained relatively constant or declined slightly during summer and autumn in 1-, 2-, and 3-year-old needles. In October, the pigment content was highest in 1-year-old needles, and lowest in 3-year-old needles. Our study indicated that total carbohydrate and pigment contents were affected by needle age classes and seasons.


2018 ◽  
Vol 13 (1) ◽  
pp. e25501
Author(s):  
Adrian Morawiak ◽  
Joanna Gutral ◽  
Marzena Cypryańska ◽  
John Nezlek

Participants in the present study (82 high school students and 60 seniors) used a version of the Ten Item Personality Inventory (TIPI) to describe their past (10 years ago), present, and future (10 years from the present) selves. From the TIPI we derived measures of positive and negative self-evaluation. We analyzed these data with 2 (young-old) x 3 (past, present, and future) ANOVAs. Consistent with previous research, for positive self-evaluations, we found that younger people thought they were better now than they had been in the past and would be better in the future than they were now, and older people thought that had been better in the past than they were now, and that they were better now than they would be in the future. In contrast, and inconsistent with previous research, for negative self-evaluations, we found few differences among ratings of the three selves. We provide a tentative explanation of these results based on possible differences in how positive and negative age related stereotypes are incorporated into self-evaluations. Previous research has not distinguished positive and negative self-evaluations when examining differences among possible selves, and we believe the present results suggest that this might be a fruitful area of inquiry.


Author(s):  
О.В. Кадникова ◽  
С.С. Смагина ◽  
К.А. Демиденко

Актуальность проблемы исследования агрессивности воспитанников учреждения интернатного типа определяется острой социальной значимостью проблем воспитания и развития детей, оставшихся без попечения родителей, а также недостаточной освещенностью и проработанностью проблемы подростковой агрессивности в микросоциальной среде, формирующейся в условиях детского дома и учреждениях интернатного типа. Целью исследования является выявление психологических особенностей агрессивности воспитанников учреждения интернатного типа. Ведущими методами исследования являются опросник Ильина «Личностная агрессивность и конфликтность»; детский вариант методики Розенцвейга «Исследование реакций человека на фрустрацию»; опросник Басса-Дарки, предназначенный для диагностики различных видов агрессивных реакций; а также методы математической и статистической обработки данных. В качестве теоретико-методологической основы исследования выступают труды отечественных и зарубежных исследователей по вопросам агрессии и агрессивного поведения детей, влияния ведущих психических новообразований на формирование личности и индивидуальных особенностей поведения подростков; а также основные подходы к изучению сиротства. Результаты исследования показали, что при возникновении фрустрирующей и конфликтной ситуаций «семейно депривированные» подростки склонны к агрессивному реагированию статистически значимо чаще, чем их сверстники, воспитывающиеся в семье; при этом агрессивность скорее имеет неосознаваемый и защитный характер. Воспитанники интернатного учреждения подросткового возраста характеризуются следующими психологическими особенностями проявления агрессивности: преобладанием экстрапунитивных реакций самозащитного типа; низким уровнем фрустрационной толерантности; высоким уровнем враждебности; преобладанием физической агрессии над косвенной. К наиболее выраженным формам проявления агрессивности подростков детского дома относятся вербальная, физическая агрессии, подозрительность и обидчивость. К проявлениям «позитивной агрессивности» воспитанников детского дома относится наступательность (напористость и настойчивость). Полученные результаты обуславливают разработку практических рекомендации по проведению коррекционно-развивающих мероприятий с агрессивными подростками, воспитывающимися в учреждениях интернатного типа, а также могут послужить основой для создания программы психологических тренингов по созданию благоприятных условий для оптимизации межличностного взаимодействия между детьми. The problem of children’s up-bringing and development as well as their aggressive behavior (the children who are placed in residential institutions) is of great social significance. The issue of teenage aggressiveness in micro social environment, in conditions of orphanage or special boarding school, requires detailed analysis and wide highlighting. The purpose of the research is the identification of psychological aspects of the aggression of the children living in residential institutions. The key research methods are the following: questionnaire by Ilyin “Individual Aggression and Proneness to Conflict”, behavior assessment system for children Picture Frustration Study by Saul Rosenzweig, the Buss-Durke Aggression Questionnaire as well as mathematical and statistical data processing. The research theoretical and methodological framework for the aggression, aggressive children behavior, age-related psychiatric changes, in forming of personality and individual characteristics of adolescent behavior, is essentially based on the works of Russian and foreign researchers. The results of the research revealed that children deprived of a family environment in a frustrating and conflict situation tend to behave aggressively compared with their peers from family environment. It should be noticed that this aggression is of unconscious and protective nature. The adolescents living in residential institutions are characterized by the following psychological particularities of aggression: extra-punitive response of protective nature, low frustration tolerance, high hostility level and physical aggression prevailing over indirect one. The main forms of aggression of the adolescents living in residential institutions are verbal aggressiveness, physical aggression, suspicion and resentment. The acts of positive aggression are assertiveness and persistence. The results provide practical recommendations for conducting of the remedial and development activities among aggressive teens living in residential institutions. Moreover, these results can be used for developing of the program for psychological training in order to provide favorable conditions for interpersonal interactions among children.


Author(s):  
A. Markova ◽  
V. Serebryakov

The article is devoted to the observation of differences in relation between aggressive behavior of related species of Flycatchers (Muscicapidae) family and behavior acts in naturally watering places. Observations have reviled the timing separation between presence and engagement of Flycatchers in morning hours and relation with acts of aggression. Each representative of Flycatchers family is using the watering place in different ways. The correlation between intraspecific and interspecific contacts with the predominance of interspecific and highly aggressive interactions has been analyzed. The rating of successfulness of the acts of aggression has been established for every particular group of Flycatchers. It demonstrates the energetic justification of aggressive behavior for spotter, red-breasted and pied flycatchers but energetic overspend and failure for collared flycatcher.


Author(s):  
E. A. Dubinin ◽  

The age-related variability of the abrasion degree of the masticatory surface of the first lower molar in the Northern Priokhotye population of the Siberian chipmunk has been studied. It has been revealed that, in young of the current year, from the time they abandoning breeding burrows to the hibernation period, the index of abrasion of the masticatory surface m1 is 0.6-3.5 %. The area of exposed dentin on the molar masticatory surface increases annually by 5-6 % averagely in overwintered adult animals. According to the abrasion index, 4-5 age classes are distinguished in the population. The group of animals aged 1+ yrs dominates in number (40.8 %). The specific survival rate of individuals in the range from 1 to 3 years is approximately 0.5. After three years, it drops sharply (0.23). Less than 3 % of individuals survive up to 4 years or more in the population.


2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Yongzhi Cao ◽  
Haibin Zhao ◽  
Zhao Wang ◽  
Changming Zhang ◽  
Yuehong Bian ◽  
...  

Abstract Maternal fertility declines irreversibly with aging, and advanced maternal age is mostly related to impaired oocyte quality. The flavonol compound quercetin is considered to be an anti-aging agent due to its cytoprotective actions as an antioxidant. However, its role and mechanisms on aged oocytes are unclear. In this study, the quercetin promotes in vitro maturation (IVM) and early embryonic development of oocytes from aged mice. It is extended these findings in human oocytes, showing that quercetin promotes the IVM rate by 19.6% and increases the blastocyst formation rate by 15.5% compared to untreated controls. The overall oocyte quality of aged mice is improved by quercetin treatment, assessed as spindle/chromosome morphology and cortical granule distribution. Mitochondria is the primary endogenous source of age-related oxidative stress, and an RNA-seq analysis of quercetin-treated oocytes reveals molecular insights including scavenged mitochondrial-ROS, reduced apoptosis, and improved autophagy. Further, this study demonstrates that quercetin reduces ROS via SIRT3-mediated acetylation of SOD2’s K68 residue. Thus, beyond demonstrating that quercetin confers beneficial mitochondria-related impacts in aged oocytes, this study illustrates a potential strategy to prevent or delay oocyte aging and to improve success rates of assisted human reproductive technologies (ART).


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