scholarly journals Anthropogenic activities are associated with shorter telomeres in chicks of Adélie penguin (Pygoscelis adeliae)

Polar Biology ◽  
2021 ◽  
Author(s):  
Jilda Alicia Caccavo ◽  
Thierry Raclot ◽  
Timothée Poupart ◽  
Yan Ropert-Coudert ◽  
Frédéric Angelier

AbstractDefining the impact of anthropogenic stressors on Antarctic wildlife is an active aim for investigators. Telomeres represent a promising molecular tool to investigate the fitness of wild populations, as their length may predict longevity and survival. We examined the relationship between telomere length and human exposure in Adélie penguin chicks (Pygoscelis adeliae) from East Antarctica. Telomere length was compared between chicks from areas with sustained human activity and on neighboring protected islands with little or no human presence. Adélie penguin chicks from sites exposed to human activity had significantly shorter telomeres than chicks from unexposed sites in nearby protected areas, with exposed chicks having on average 3.5% shorter telomeres than unexposed chicks. While sampling limitations preclude our ability to draw more sweeping conclusions at this time, our analysis nonetheless provides important insights into measures of colony vulnerability. More data are needed both to understand the proximate causes (e.g., stress, feeding events) leading to shorter telomeres in chicks from human exposed areas, as well as the fitness consequences of reduced telomere length. We suggest to further test the use of telomere length analysis as an eco-indicator of stress in wildlife among anthropized sites throughout Antarctica.

1998 ◽  
Vol 10 (4) ◽  
pp. 449-454 ◽  
Author(s):  
Eric J. Woehler ◽  
Martin J. Riddle

The relationship between colony area and population density of Adélie penguins Pygoscelis adeliae was examined to determine whether colony area, measured from aerial or satellite imagery, could be used to estimate population density, and hence detect changes in populations over time. Using maps drawn from vertical aerial photographs of Adélie penguin colonies in the Mawson region, pair density ranged between 0.1 and 3.1 pairs m−2, with a mean of 0.63 ± 0.3 pairs m−2. Colony area explained 96.4% of the variance in colony populations (range 90.4–99.6%) for 979 colonies at Mawson. Mean densities were not significantly different among the 19 islands in the region, but significant differences in mean pair density were observed among colonies in Mawson, Whitney Point (Casey, East Antarctica) and Cape Crozier (Ross Sea) populations. The relationship between colony area and population may be locality-and/or species-specific, and a robust data set is required to validate the relationship.


2008 ◽  
Vol 295 (5) ◽  
pp. R1671-R1679 ◽  
Author(s):  
Mireille Raccurt ◽  
Fannie Baudimont ◽  
Julien Tirard ◽  
Benjamin Rey ◽  
Elodie Moureaux ◽  
...  

Rapid growth is of crucial importance for Adélie penguin chicks reared during the short Antarctic summer. It partly depends on the rapid ontogenesis of fat stores that are virtually null at hatching but then develop considerably (×40) within a month to constitute both an isolative layer against cold and an energy store to fuel thermogenic and growth processes. The present study was aimed at identifying by RT-PCR the major transcriptional events that chronologically underlie the morphological transformation of adipocyte precursors into mature adipocytes from hatching to 30 days of age. The peak expression of GATA binding protein 3, a marker of preadipocytes, at day 7 posthatch indicates a key proliferation step, possibly in relation to the expression of C/EBPα (C/EBPα). High plasma total 3,5,3′-triiodo-l-thyronine (T3) levels and high levels of growth hormone receptor transcripts at hatching suggested that growth hormone and T3 play early activating roles to favor proliferation of preadipocyte precursors. Differentiation and growth of preadipocytes may occur around day 15 in connection with increased abundance of transcripts encoding IGF-1, proliferator-activated receptor-γ, and C/EBPβ, gradually leading to functional maturation of metabolic features of adipocytes including lipid uptake and storage (lipoprotein lipase, fatty-acid synthase) and late endocrine functions (adiponectin) by day 30. Present results show a close correlation between adipose tissue development and chick biology and a difference in the scheduled expression of regulatory factors controlling adipogenesis compared with in vitro studies using cell lines emphasizing the importance of in vivo approaches.


2005 ◽  
Vol 17 (1) ◽  
pp. 57-66 ◽  
Author(s):  
STEVEN D. EMSLIE ◽  
ERIC J. WOEHLER

We investigated 17 abandoned Adélie penguin (Pygoscelis adeliae) colonies in the Windmill Islands, East Antarctica, in summer 2002/03. Forty radiocarbon dates on penguin bones and eggshells from 13 of these sites indicate a near continuous occupation by breeding penguins in this region for over 9000 years. These dates refine the recent geological record in this region and indicate that deglaciation of the northern islands occurred much earlier than previously suggested. Dietary remains from these sites include at least 23 taxa of cephalopods and teleost fish. Quantification of these remains indicates significant fluctuations in the relative abundance of two of the more common major prey taxa. The Antarctic silverfish (Pleuragramma antarcticum Boulenger) was the most common teleost prey during all time periods represented by the ages of the sites, but preservational factors may explain a gradual decrease in the remains of this species in increasingly older sites. The most common cephalopod in the sediments was the squid, Psychroteuthis glacialis Thiele, which occurred in low numbers in most sites except one (Site 75). An unusually high number of squid beaks preserved in Site 75, dating to approximately 5700–6100 cal. yr BP, does not correlate with a decrease in fish prey at that time. The high number of abandoned penguin colonies (> 200) in the Windmill Islands may be due to population cycles in the past in association with low nest-site fidelity and movement by breeding penguins to new sites within this region.


2013 ◽  
Vol 305 (9) ◽  
pp. R1065-R1075 ◽  
Author(s):  
Anaïs Fongy ◽  
Caroline Romestaing ◽  
Coralie Blanc ◽  
Nicolas Lacoste-Garanger ◽  
Jean-Louis Rouanet ◽  
...  

The ontogeny of pectoralis muscle bioenergetics was studied in growing Adélie penguin chicks during the first month after hatching and compared with adults using permeabilized fibers and isolated mitochondria. With pyruvate-malate-succinate or palmitoyl-carnitine as substrates, permeabilized fiber respiration markedly increased during chick growth (3-fold) and further rose in adults (1.4-fold). Several markers of muscle fiber oxidative activity (cytochrome oxidase, citrate synthase, hydroxyl-acyl-CoA dehydrogenase) increased 6- to 19-fold with age together with large rises in intermyofibrillar (IMF) and subsarcolemmal (SS) mitochondrial content (3- to 5-fold) and oxidative activities (1.5- to 2.4-fold). The proportion of IMF relative to SS mitochondria increased with chick age but markedly dropped in adults. Differences in oxidative activity between mitochondrial fractions were reduced in adults compared with hatched chicks. Extrapolation of mitochondrial to muscle respirations revealed similar figures with isolated mitochondria and permeabilized fibers with carbohydrate-derived but not with lipid-derived substrates, suggesting diffusion limitations of lipid substrates with permeabilized fibers. Two immunoreactive fusion proteins, mitofusin 2 (Mfn2) and optic atrophy 1 (OPA1), were detected by Western blots on mitochondrial extracts and their relative abundance increased with age. Muscle fiber respiration was positively related with Mfn2 and OPA1 relative abundance. Present data showed by two complementary techniques large ontogenic increases in muscle oxidative activity that may enable birds to face thermal emancipation and growth in childhood and marine life in adulthood. The concomitant rise in mitochondrial fusion protein abundance suggests a role of mitochondrial networks in the skeletal muscle processes of bioenergetics that enable penguins to overcome harsh environmental constraints.


2018 ◽  
Vol 8 (1) ◽  
pp. 33-41 ◽  
Author(s):  
BEATRICE AYORKOR MENSAH ◽  
ROSINA KYEREMATEN ◽  
TED ANNANG ◽  
SAMUEL ADU-ACHEAMPONG

Mensah BA, Kyerematen R, Annang T. 2018. Influence of human activity on diversity and abundance of insects in three wetland environments in Ghana. Bonorowo Wetlands 2: 33-41. The Wetland environment is unique with unique biota that includes insects. Insects serve as indicators of environmental health, nevertheless, the recent spate of human encroachment on wetlands is likely to affect its unique biotic composition, and this phenomenon poses a threat to the wetland environment. The physical and chemical quality of studied habitats in this research provided background information for comparison against the established quality standard of the wetland environment. The study involved reconnaissance surveys, insect trapping and social surveys on the impact of anthropogenic activities on insect diversity and abundance in and around the wetland environment. Twenty-two insect orders belonging to 112 families were sampled from different sites along the Sakumono, Kpeshie, and Muni-Pomadze wetlands. Species diversity and abundance were significantly different among the various locations with the most diverse being Kpeshie. Water within wetlands in Kpeshie was the most polluted although it had a positive correlation with insect diversity and abundance. Results of a survey of selected communities showed that majority of the residents had a low level of education with less appreciation of issues involving the environment including pollution. Majority of people within the surveyed communities were unable to access decent toilet facilities and publicly demarcated waste disposal sites. There was no coordinated and concerted effort to manage these three wetlands two of which are designated Ramsar sites. Activities such as farming, discharge of domestic garbage, improper fishing practices, improper disposal of industrial and human waste are increasing the pollution risk of these wetland environments.


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