Parental age does not influence offspring telomeres during early life in common gulls (Larus canus).

Parental age can affect offspring telomere length through heritable and epigenetic-like effects, but at what stage during development these effects are established is not well known. To address this, we conducted a cross-fostering experiment in common gulls (Larus canus) that enabled us distinguish between pre- and post-natal parental age effects on offspring telomere length. Whole clutches were exchanged after clutch completion within and between parental age classes (young and old) and blood samples were collected from chicks at hatching and during the fastest growth phase (11 days later) to measure telomeres.

Age-dependent expression of cancer-related genes in a long-lived seabird.

Studies of model animals like mice and rats have led to great advances in our understanding of the process of tumorigenesis, but this line of study has less to offer for understanding the mechanisms of cancer resistance. Increasing the diversity of nonmodel species from the perspective of molecular mechanisms of natural cancer resistance can lead to new insights into the evolution of protective mechanisms against neoplastic processes and to a wider understanding of natural cancer defense mechanisms. Such knowledge could then eventually be harnessed for the development of human cancer therapies.

Uropygial gland size: a marker of phenotypic quality that shows no senescence in a long-lived seabird.

Studies of senescence in the wild have traditionally focused on traits like survival or fecundity. Although efforts to measure other salient phenotypic traits and markers of relevant physiological processes are rapidly increasing, traits related to self-maintenance remain understudied in the context of aging. Uropygial or preen gland is a holocrine gland, exclusive to birds, directly linked to self-maintenance of the quality of plumage.

Age-specific patterns of maternal investment in common gull egg yolk.

While the general patterns of age-specific changes in reproductive success are quite well established in long-lived animals, we still do not know if allocation patterns of maternally transmitted compounds are related to maternal age. We measured the levels of yolk testosterone, carotenoids and vitamins A and E in a population of known-aged common gulls () and found an age-specific pattern in yolk lutein and vitamin A concentrations. Middle-aged mothers allocated more of these substances to yolk compared to young and old mothers.

Variation in the Markers of Nutritional and Oxidative State in a Long-Lived Seabird: Associations with Age and Longevity.

Age-related declines in life-history traits have been widely observed in free-living animals. Several theories link senescence to oxidative stress. The aim of this study was to measure several widely used markers of oxidative and nutritional state in a long-lived seabird, the common gull (Larus canus), in order to assess the suitability of these markers for describing deterioration in physiological condition associated with chronological age and survival.

Skin pentosidine and telomere length do not covary with age in a long-lived seabird.

The questions about why and how senescence occurs in the wild are among the most pertinent ones in evolutionary ecology. Telomere length is a commonly used marker for aging, while other biomarkers of aging have received considerably less attention. Here we studied how another potent indicator of aging-skin pentosidine concentration-relates to age and blood telomere length in a long-lived seabird with well-documented reproductive senescence.

"Hidden" reproductive conflict between mates in a wild bird population.

Environmental conditions experienced by a female prior to reproducing may be influenced by her mate. Part of such an indirect effect of a male on his partner's reproduction may be genetic (indirect genetic effect). However, a female's direct and a male's indirect genetic effects need not align.

Exploring plasticity in the wild: laying date-temperature reaction norms in the common gull Larus canus.

Exploration of causal components of plasticity is important for insight into evolutionary dynamics and an organism's ability to respond to climate change. Among individuals, variation in plasticity can be due to genotype-environment interaction (GxE) or a result from environmental effects associated with an individual. We investigated plasticity for laying date in the common gulls Larus canus, using data collected in Estonia during 37 years (n=11624 records on 2262 females, with 472 relatives).

Reproductive success in presenescent common gulls (Larus canus): the importance of the last year of life.

Survival selection against individuals of inferior quality (measured as breeding success) has been proposed to account for the increase in average reproductive success with advancing age in presenescent birds. This so-called selection hypothesis relies on quality-dependent survival. In the present breeding performance study of common gulls, Larus canus, this assumption was not verified.