Plastic ingestion risk is related to the anthropogenic activity and breeding stage in an Antarctic top predator seabird species

2020 ◽  
Vol 157 ◽  
pp. 111351 ◽  
Author(s):  
A.E. Ibañez ◽  
L.M. Morales ◽  
D.S. Torres ◽  
P. Borghello ◽  
N.S. Haidr ◽  
...  
Keyword(s):  
Anthropogenic Activity ◽  
Top Predator ◽  
Seabird Species ◽  
Breeding Stage

Leucocyte profiles and body condition in breeding brown boobies and red-tailed tropicbirds: effects of breeding stage and sex

2013 ◽  
Vol 61 (2) ◽  
pp. 178 ◽  
Author(s):  
Nina Dehnhard ◽  
Janos C. Hennicke
Keyword(s):  
Body Condition ◽  
Foraging Strategy ◽  
Seabird Species ◽  
Breeding Stage ◽  
Christmas Island ◽  
Investment In Reproduction ◽  
Males And Females ◽  
Species Specific ◽  
Phaethon Rubricauda ◽  
Leucocyte Profiles

Foraging in a habitat with highly unpredictable availability of prey, breeding seabirds have to balance their investment in reproduction with their own energetic requirements, including their immune system. This study aimed to investigate the influence of breeding stage (incubation and chick rearing) and sex on body condition and leucocyte profiles in two sympatrically breeding tropical seabird species on Christmas Island, Indian Ocean: the strongly size-dimorphic, inshore-foraging brown booby (Sula leucogaster) and the monomorphic offshore-foraging red-tailed tropicbird (Phaethon rubricauda). Brown booby males were in poorer body condition than females. Male brown boobies had a higher heterophil/lymphocyte (H/L) ratio (indicating higher stress levels), and higher eosinophil numbers (suggesting higher intestinal parasite loads) than females, and sex differences in H/L ratio and body condition were more pronounced during chick rearing. The results suggest that in brown boobies, incubation was energetically less demanding for males than chick rearing, but that the smaller males were energetically more challenged than females during both breeding stages. In the monomorphic red-tailed tropicbird, there were no differences in body condition between sexes and breeding stage, and there was no influence of sex or breeding stage on the leucocyte profiles. The results suggest that incubation and chick rearing are equally demanding for males and females, and that the increased energetic demands of chick rearing are likely to be buffered by a bimodal foraging strategy by both sexes. Our results show that breeding stage as well as sex- and species-specific foraging behaviour can affect leucocyte profiles and particularly the H/L ratio differentially in sympatrically breeding seabird species.

scholarly journals Using citizen-science data to identify local hotspots of species occurrence

2014 ◽  
Author(s):  
Eric J. Ward ◽  
Kristin N Marshall ◽  
Todd Hass ◽  
Scott F. Pearson ◽  
Gerald Joyce ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Puget Sound ◽  
Range Shift ◽  
Anthropogenic Activity ◽  
Occupancy Models ◽  
Science Data ◽  
Seabird Species ◽  
Nearshore Ecosystems ◽  
Temporal And Spatial ◽  
Spatial Patchiness

Seabirds have been identified and used as indicators of ecosystem processes such as climate change, and anthropogenic activity in nearshore ecosystems around the globe. Temporal and spatial trends have been documented at large spatial scales, but few studies have examined fine scale spatial patterns, by species or functional group, because . In this paper, we apply spatial occupancy models to assess the spatial patchiness and interannual trends of 18 seabird species in the Puget Sound region (Washington state, USA). Our dataset, the Puget Sound Seabird Survey, is unique in that represents a seven year study, collected in winter months (October – April), and is collected at an extremely fine spatial scale (62 sites in the current analysis). Despite historic declines of seabirds in the region over the last 50 years, results from our study are optimistic, suggesting increases in probabilities of occurrence for 14 of the 18 species included. We found support for declines in occurrence for white-winged scoters, brants, and 2 species of grebes. The declines of Western grebes in particular are troubling, but in agreement with other recent studies that have shown support for a range shift south in recent years, to the California Current.

scholarly journals Using citizen-science data to identify local hotspots of species occurrence

2014 ◽  
Author(s):  
Eric J. Ward ◽  
Kristin N Marshall ◽  
Todd Hass ◽  
Scott F. Pearson ◽  
Gerald Joyce ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Puget Sound ◽  
Range Shift ◽  
Anthropogenic Activity ◽  
Occupancy Models ◽  
Science Data ◽  
Seabird Species ◽  
Nearshore Ecosystems ◽  
Temporal And Spatial ◽  
Spatial Patchiness

Seabirds have been identified and used as indicators of ecosystem processes such as climate change, and anthropogenic activity in nearshore ecosystems around the globe. Temporal and spatial trends have been documented at large spatial scales, but few studies have examined fine scale spatial patterns, by species or functional group, because . In this paper, we apply spatial occupancy models to assess the spatial patchiness and interannual trends of 18 seabird species in the Puget Sound region (Washington state, USA). Our dataset, the Puget Sound Seabird Survey, is unique in that represents a seven year study, collected in winter months (October – April), and is collected at an extremely fine spatial scale (62 sites in the current analysis). Despite historic declines of seabirds in the region over the last 50 years, results from our study are optimistic, suggesting increases in probabilities of occurrence for 14 of the 18 species included. We found support for declines in occurrence for white-winged scoters, brants, and 2 species of grebes. The declines of Western grebes in particular are troubling, but in agreement with other recent studies that have shown support for a range shift south in recent years, to the California Current.

Prey-field use by a Southern Ocean top predator: enhanced understanding using integrated datasets

2015 ◽  
Vol 526 ◽  
pp. 169-181 ◽  
Author(s):  
M Bedford ◽  
J Melbourne-Thomas ◽  
S Corney ◽  
T Jarvis ◽  
N Kelly ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Top Predator

Testing ecological release as a compensating mechanism for mass mortality in a keystone predator

2020 ◽  
Vol 637 ◽  
pp. 59-69 ◽  
Author(s):  
J Sullivan-Stack ◽  
BA Menge
Keyword(s):  
Community Dynamics ◽  
Limiting Factor ◽  
Sea Star ◽  
Top Predator ◽  
Oregon Coast ◽  
Ecological Release ◽  
Keystone Predator ◽  
Pisaster Ochraceus ◽  
Wasting Syndrome

Top predator decline has been ubiquitous across systems over the past decades and centuries, and predicting changes in resultant community dynamics is a major challenge for ecologists and managers. Ecological release predicts that loss of a limiting factor, such as a dominant competitor or predator, can release a species from control, thus allowing increases in its size, density, and/or distribution. The 2014 sea star wasting syndrome (SSWS) outbreak decimated populations of the keystone predator Pisaster ochraceus along the Oregon coast, USA. This event provided an opportunity to test the predictions of ecological release across a broad spatial scale and determine the role of competitive dynamics in top predator recovery. We hypothesized that after P. ochraceus loss, populations of the subordinate sea star Leptasterias sp. would grow larger, more abundant, and move downshore. We based these predictions on prior research in Washington State showing that Leptasterias sp. competed with P. ochraceus for food. Further, we predicted that ecological release of Leptasterias sp. could provide a bottleneck to P. ochraceus recovery. Using field surveys, we found no clear change in density or distribution in Leptasterias sp. populations post-SSWS, and decreases in body size. In a field experiment, we found no evidence of competition between similar-sized Leptasterias sp. and P. ochraceus. Thus, the mechanisms underlying our predictions were not in effect along the Oregon coast, which we attribute to differences in habitat overlap and food availability between the 2 regions. Our results suggest that response to the loss of a dominant competitor can be unpredictable even when based in theory and previous research.

Impact of anthropogenic activity on habitat of Zebra fish (Danio devario) in River Nimmi of Western Himalaya, Uttarakhand, India

2017 ◽  
Vol 18 (1&2) ◽  
pp. 197-205
Author(s):  
Bipin Kumar Sati ◽  
◽  
Ashish Thapliyal ◽  
Madhu Thapliyal ◽  
◽  
...  
Keyword(s):  
Western Himalaya ◽  
Anthropogenic Activity ◽  
Zebra Fish

scholarly journals Steller’s sea cow genome suggests this species began going extinct before the arrival of Paleolithic humans

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fedor S. Sharko ◽  
Eugenia S. Boulygina ◽  
Svetlana V. Tsygankova ◽  
Natalia V. Slobodova ◽  
Dmitry A. Alekseev ◽  
...  
Keyword(s):  
Bering Sea ◽  
De Novo ◽  
Anthropogenic Activity ◽  
Commander Islands ◽  
The North ◽  
Extinction Process ◽  
Sea Cow ◽  
The North Pacific ◽  
The Bering Sea ◽  
Woolly Mammoth

AbstractAnthropogenic activity is the top factor directly related to the extinction of several animal species. The last Steller’s sea cow (Hydrodamalis gigas) population on the Commander Islands (Russia) was wiped out in the second half of the 18th century due to sailors and fur traders hunting it for the meat and fat. However, new data suggests that the extinction process of this species began much earlier. Here, we present a nuclear de novo assembled genome of H. gigas with a 25.4× depth coverage. Our results demonstrate that the heterozygosity of the last population of this animal is low and comparable to the last woolly mammoth population that inhabited Wrangel Island 4000 years ago. Besides, as a matter of consideration, our findings also demonstrate that the extinction of this marine mammal starts along the North Pacific coastal line much earlier than the first Paleolithic humans arrived in the Bering sea region.

scholarly journals Ground-Based MAX-DOAS Observations of Tropospheric NO2 and HCHO During COVID-19 Lockdown and Spring Festival Over Shanghai, China

2021 ◽  
Vol 13 (3) ◽  
pp. 488
Author(s):  
Aimon Tanvir ◽  
Zeeshan Javed ◽  
Zhu Jian ◽  
Sanbao Zhang ◽  
Muhammad Bilal ◽  
...  
Keyword(s):  
Air Quality ◽  
Anthropogenic Activities ◽  
Anthropogenic Activity ◽  
Hysplit Model ◽  
Vertical Column ◽  
Weekly Cycle ◽  
Spring Festival ◽  
Level 1 ◽  
Reduced Mobility ◽  
The Impact

Reduced mobility and less anthropogenic activity under special case circumstances over various parts of the world have pronounced effects on air quality. The objective of this study is to investigate the impact of reduced anthropogenic activity on air quality in the mega city of Shanghai, China. Observations from the highly sophisticated multi-axis differential optical absorption spectroscope (MAX-DOAS) instrument were used for nitrogen dioxide (NO2) and formaldehyde (HCHO) column densities. In situ measurements for NO2, ozone (O3), particulate matter (PM2.5) and the air quality index (AQI) were also used. The concentration of trace gases in the atmosphere reduces significantly during annual Spring Festival holidays, whereby mobility is reduced and anthropogenic activities come to a halt. The COVID-19 lockdown during 2020 resulted in a considerable drop in vertical column densities (VCDs) of HCHO and NO2 during lockdown Level-1, which refers to strict lockdown, i.e., strict measures taken to reduce mobility (43% for NO2; 24% for HCHO), and lockdown Level-2, which refers to relaxed lockdown, i.e., when the mobility restrictions were relaxed somehow (20% for NO2; 22% for HCHO), compared with pre-lockdown days, as measured by the MAX-DOAS instrument. However, for 2019, a reduction in VCDs was found only during Level-1 (24% for NO2; 6.62% for HCHO), when the Spring Festival happened. The weekly cycle for NO2 and HCHO depicts no significant effect of weekends on the lockdown. After the start of the Spring Festival, the VCDs of NO2 and HCHO showed a decline for 2019 as well as 2020. Backward trajectories calculated using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model indicated more air masses coming from the sea after the Spring Festival for 2019 and 2020, implying that a low pollutant load was carried by them. No impact of anthropogenic activity was found on O3 concentration. The results indicate that the ratio of HCHO to NO2 (RFN) fell in the volatile organic compound (VOC)-limited regime.

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