scholarly journals Nest defense and parental investment in Song Sparrows (Melospiza melodia)

2016 ◽  
Vol 94 (7) ◽  
pp. 473-477 ◽  
Author(s):  
N. Morrell ◽  
K.M. Johnson ◽  
C.E. Tarwater ◽  
P. Arcese
Keyword(s):  
Clutch Size ◽  
Parental Investment ◽  
Individual Variation ◽  
Alarm Call ◽  
Nest Defense ◽  
Melospiza Melodia ◽  
Reproductive Value ◽  
Parental Age ◽  
Altricial Birds ◽  
Age And Sex

Individual variation in nest defense behaviour is common in altricial birds, but despite clear predictions about why such variation exists, there is no consensus on its causes. We tested for an influence of five predictors of individual variation in nest defense behaviour, including time of season, offspring age, parental age and sex, and clutch size in a well-studied Song Sparrow (Melospiza melodia (A. Wilson, 1810)) population. We recorded parental responses to a standardized human approach and used model selection to assess support for each predictor. Parents tended to approach observers less closely and alarm-call less as the breeding season progressed, indicating a modest seasonal decline in parental nest defense, which is consistent with the hypothesis that the reproductive value of offspring influenced parental defense behaviour. Clutch size effect estimates were insignificant, but it was weakly supported as a predictor of nest defense, which is expected if parental investment in defense and current reproductive effort are positively related. Offspring age, as well as parental age and sex, received little or no support as affecting parent nest defense. Our results offer limited support for the hypothesis that the reproductive value of offspring affects parental nest defense.

Parental Investment in Clutch Size and Egg Size in the Ural Owl Strix uralensis

1986 ◽  
Vol 17 (4) ◽  
pp. 309 ◽  
Author(s):  
Hannu Pietiainen ◽  
Pertti Saurola ◽  
Risto A. Vaisanen
Keyword(s):  
Clutch Size ◽  
Parental Investment ◽  
Egg Size ◽  
Ural Owl

scholarly journals Parental Investment in Children with Chronic Disease: The Effect of Child's and Mother's Age

2007 ◽  
Vol 5 (4) ◽  
pp. 147470490700500 ◽  
Author(s):  
Sigal Tifferet ◽  
Orly Manor ◽  
Shlomi Constantini ◽  
Orna Friedman ◽  
Yoel Elizur
Keyword(s):  
Parental Investment ◽  
Maternal Age ◽  
Direct Care ◽  
Reproductive Value ◽  
Negatively Associated ◽  
Investment In Children ◽  
Maternal Age Effect ◽  
Neurological Conditions ◽  
Mother’S Age ◽  
The Impact

Parents do not invest their resources in their children equally. Three factors which elicit differential parental investment are the parent's reproductive value, the child's reproductive value (RV), and the impact of the investment on the child (II). As the child matures, his RV increases while the II may decrease. This raises a question regarding the favored strategy of investment by child age. It was hypothesized that different categories of parental investment generate different age-based strategies. Emotional investment, such as maternal worrying for the child's health, was hypothesized to increase with the child's age, while direct care was hypothesized to decrease with the child's age. Both categories were hypothesized to increase with the mother's age at childbirth. 137 Israeli mothers of children with chronic neurological conditions reported levels of worrying for their child and levels of change in direct care. Maternal worrying about the child's health was positively associated with the child's age at diagnosis and the severity of his illness, and negatively associated with the time from diagnosis. An increase in direct care was positively associated with maternal age at childbirth and illness severity, and negatively associated with the time from diagnosis, and the duration of the marriage. Contrary to the hypothesis, the child's age had no effect on changes in direct care. It appears that in mothers of children with adverse neurological conditions, child and maternal age effect parental investment differently. While the child's age is related to maternal worrying about his health, the mother's age at childbirth is related to changes in direct care.

Songs of song sparrows (Melospiza melodia): individual variation and dialects

1972 ◽  
Vol 50 (3) ◽  
pp. 301-309 ◽  
Author(s):  
Margaret A. Harris ◽  
Robert E. Lemon
Keyword(s):  
Individual Variation ◽  
Melospiza Melodia ◽  
Populated Area ◽  
Male Song ◽  
Relative Occurrence ◽  
Song Sparrows

Male song sparrows from two areas in Quebec had repertoires of several song patterns, each one of which was generally made up of two repeated units, or syllables, plus unrepeated note complexes. Variability between individuals was large, but there was also some similarity: while most syllable types were sung by one individual only, some were shared with others in the population. The relative occurrence of the different syllable types was similar in two sites at Pare Cote Ste. Catherine but between Pare Cote Ste. Catherine and Mont St. Hilaire (separated by 23 mi) there was almost complete lack of similarity, which was taken as evidence that dialects existed. Birds from the less densely populated area at Mont St. Hilaire had slightly smaller repertoires of syllables and song patterns.

Parental Investment Theory and Nest Defense by Eastern Kingbirds

2009 ◽  
Vol 121 (1) ◽  
pp. 1 ◽  
Author(s):  
Lucas J. Redmond ◽  
Michael T. Murphy ◽  
Amy C. Dolan ◽  
Karen Sexton
Keyword(s):  
Parental Investment ◽  
Nest Defense ◽  
Investment Theory ◽  
Parental Investment Theory

scholarly journals Factors affecting individual variation in nest-defense intensity in colonially breeding Black-tailed Gulls (Larus crassirostris)

2011 ◽  
Vol 89 (10) ◽  
pp. 938-944 ◽  
Author(s):  
Kentaro Kazama ◽  
Yasuaki Niizuma ◽  
Kentaro Q. Sakamoto ◽  
Yutaka Watanuki
Keyword(s):  
Individual Variation ◽  
Physiological State ◽  
Breeding Birds ◽  
Egg Laying ◽  
Nest Defense ◽  
Laying Date ◽  
Plasma Testosterone ◽  
Factors Affecting ◽  
Corvus Macrorhynchos ◽  
Males And Females

The physiological state of parent birds combined with the value of their clutch may affect the intensity of their nest defense. In colonially breeding birds, nest-defense intensity may also be affected by the behavior of neighbors. We investigated individual variation in the nest-defense intensity among colonial Black-tailed Gulls ( Larus crassirostris Vieillot, 1818) over 2 years. Only 30%–40% of males attacked a decoy of an egg predator (Large-billed Crow ( Corvus macrorhynchos Wagler, 1827)), and the other males and females rarely attacked. Males attacking the decoy had higher levels of plasma testosterone than males that did not attack. Each male’s, but not female’s, nest-defense intensity was consistent throughout the incubation period and also across years. The intensity was not related to egg-laying date, clutch size, or age of offspring. The intensity was likely to be higher when individuals had one or more neighbors, representing higher nest-defense intensity in the year where gulls had larger number of adjacent neighboring nests (5.23 nests), but this trend was not observed in the year where they had smaller number of the neighboring nests (3.73 nests). Thus, in addition to testosterone levels, behavior of neighbors also influences the nest-defense intensity.

scholarly journals INVESTMENT IN NEST DEFENSE BY NORTHERN FLICKERS: EFFECTS OF AGE AND SEX

2006 ◽  
Vol 118 (4) ◽  
pp. 452-460 ◽  
Author(s):  
RYAN J. FISHER ◽  
KAREN L. WIEBE
Keyword(s):  
Nest Defense ◽  
Age And Sex

scholarly journals A classic question revisited in red-winged blackbirds: disentangling confounding hypotheses surrounding parental investment theory and nest defense intensity

2016 ◽  
Vol 70 (11) ◽  
pp. 1843-1856 ◽  
Author(s):  
Justin J. Shew ◽  
Jorista van der Merwe ◽  
Eric M. Schauber ◽  
Briana K. Tallitsch ◽  
Clayton K. Nielsen
Keyword(s):  
Parental Investment ◽  
Nest Defense ◽  
Investment Theory ◽  
Parental Investment Theory

scholarly journals Estimation of environmental and genetic contributions to telomere length variation in a wild mammal

2020 ◽  
Author(s):  
Sil H. J. van Lieshout ◽  
Alex Sparks ◽  
Amanda Bretman ◽  
Chris Newman ◽  
Christina D. Buesching ◽  
...  
Keyword(s):  
Telomere Length ◽  
Individual Variation ◽  
Evolutionary Dynamics ◽  
Meles Meles ◽  
Length Variation ◽  
Phenotypic Variance ◽  
Parental Age ◽  
Transgenerational Effects ◽  
Wild Mammal ◽  
Relative Contribution

Understanding individual variation in fitness-related traits requires separating the environmental and genetic determinants. Telomeres are protective caps at the ends of chromosomes that are thought to be a biomarker of senescence as their length predicts mortality risk and reflect the physiological consequences of environmental conditions. The relative contribution of genetic and environmental factors to individual variation in telomere length is however unclear, yet important for understanding its evolutionary dynamics. In particular, the evidence for transgenerational effects, in terms of parental age at conception, on telomere length is mixed. Here, we investigate the heritability of telomere length, using the ‘animal model’, and parental age at conception effects on offspring telomere length in a wild population of European badgers (Meles meles). While we found no heritability of telomere length, our power to detect heritability was low and a repeatability of 2% across individual lifetimes provides a low upper limit to ordinary heritability. However, year (25%) and cohort (3%) explained greater proportions of the phenotypic variance in telomere length. There was no support for parental age at conception effects, or for longitudinal within-parental age effects on offspring telomere length. Our results indicate a lack of transgenerational effects through parental age at conception and a low potential for evolutionary change in telomere length in this population. Instead, we provide evidence that individual variation in telomere length is largely driven by environmental variation in this wild mammal.

Number and Size of Offspring

2021 ◽  
pp. 115-128
Author(s):  
Jeffrey A. Hutchings
Keyword(s):  
Life History ◽  
Clutch Size ◽  
Parental Investment ◽  
Adaptive Significance ◽  
Offspring Size ◽  
Structural Constraints ◽  
Offspring Survival ◽  
Trade Off ◽  
Offspring Number ◽  
Parental Fitness

Offspring number and size are two of the most variable life-history traits. Among species, much of this variability can be attributed to genetic, developmental, physiological, or structural constraints. Some trait combinations are not possible because of differences associated with a species’ evolutionary history. Substantial variation in propagule number and size can exist among populations of the same species, generating questions concerning the adaptive significance of this variability. The most influential models are those attributed to Lack on clutch size and to Smith and Fretwell on offspring size. Fundamental to both sets of models is a trade-off between offspring number and parental investment per offspring. When offspring survival or fitness continuously varies with offspring size, the fitness of the parent depends on both offspring size and the number of offspring of that size that the parent can produce. If offspring survival is independent of offspring size, parental fitness is maximized when individuals maximize the production of minimally sized propagules.

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