Articles tagged with Population Ecology
New research shows Mediterranean green turtle populations are recovering, but loggerhead turtles face additional threats due to high mortality rates. The study found stable reproduction rates among loggerheads, suggesting deaths among all ages impede their recovery.
The study uses Monte Carlo computer simulation to determine the population numbers of T. rexes, with a standing population size of 20,000 adults at any given time. The total number of individuals that existed over its lifetime could have been anywhere from 140 million to 42 billion.
A new study estimates that nearly 20,000 T. rex lived concurrently, with a total of 2.5 billion individuals over their entire existence. The authors used Darmuth's Law to estimate population-level traits and the rate of fossil preservation, finding that only about 1 in 80 million T. rex survived as fossilized remains.
Researchers at Lund University investigated X and Y chromosome evolution and adaptation in a population. The results show that breaking up coevolved sets of sex chromosomes can lead to lower survival rates among offspring.
Researchers found that increased deciduous vegetation leads to higher moose populations, which in turn affects wolves and ultimately caribou. Human land use, like forestry, significantly increases vegetation productivity, contributing to caribou declines.
A new study led by the University of Maryland Baltimore County estimates the Bahama Oriole population at 1300-2800 individuals, suggesting a much larger number than previously believed. The research reveals that pine forest is an important habitat for the birds, contrary to earlier findings.
A new study reveals that weather patterns driven by El Nino influence predictable fluctuations in deer populations and synchronize different deer populations across the state. The researchers found that these synchronized population cycles can drive cycling patterns in nature.
A QUT-led study reveals jaguars in the Amazon can cope with drought and flood, but repeated exposure leads to rapid decline. The species' long-term survival is threatened by climate change and food scarcity, with predictions suggesting a potential population crash in 30 years.
A new quantitative method assesses the effects of ingested plastics on individual and population levels in sea turtles, potentially impacting growth, reproduction, and survival. The study demonstrates a crucial step towards conservation and mitigating the negative effects of plastic waste on marine ecosystems.
A recent study published in Frontiers in Ecology and Evolution has challenged the prevailing view that monarch butterfly migration mortality is a major cause of population decline. The researchers found that the size of the summer population is the main determinant of yearly variation in overwintering numbers.
A frigatebird chick suffering from a viral infection has won the 7th BMC Ecology Image competition. The winning image showcases the intricate relationships between species and their environments. David Costantini's powerful photo highlights pressing issues in ecology, including viral outbreaks affecting bird populations.
A new study using DNA metabarcoding reveals that responses to environmental stress can be detected below the species level, with higher intraspecific diversity found in resilient species. The research found significant differences in biodiversity between moderately stressed and heavily disturbed environments.
A new review of lizard data reveals that up to 2.75% of all lizards may have two or more tails, with potential ecological impacts on individual fitness and population dynamics.
A new study suggests that releasing non-essential workers in two stages is the most effective way to minimize deaths while protecting the economy. The researchers recommend gradually releasing half of the population 2-4 weeks after an initial infection peak, followed by another 3-4 months before fully lifting restrictions.
A pilot study tested the effectiveness of drones in measuring Atlantic bluefin tuna, showing they can capture images of individual fish and schools with high accuracy. The use of drones may supplement traditional fishing methods and provide valuable data for fisheries management.
A multidisciplinary team found that incorporating home ranging behavior into encounter rates could drastically change results, but only under narrow conditions. The more realistic models mimicked mass-action encounter only in specific scenarios, making it challenging to predict the direction of predictions.
A newly published study suggests that the forest elephant population size is smaller than believed, leaving the species in an even graver position. The research provides insights into a revised population count and social behavior of the forest elephants.
A recent study found that North Atlantic right whales are in poorer body condition than Southern right whales, likely due to vessel strikes, entanglement in fishing gear, and changes in food supply. This decline affects the species' reproduction, growth, and survival.
The white-lipped peccary population in Central America has declined by up to 87%, with current IUCN estimates severely underestimating the actual decline. The species plays a critical ecological role and is highly vulnerable to human influence and forest loss.
A new study by University of Alberta ecologists reveals that male squirrels who move outside their population live longer and have more offspring. In contrast, female squirrels do not reap the same benefits, losing out on family support and facing fitness costs after dispersal.
A new study found that lower elevation Silversword plants are less drought-resistant than higher elevation plants, leading to increased mortality rates. The researchers suggest using suitable habitats for the plants in a changing climate rather than breeding them with drought-resistant genes.
A study found that clownfish in Kimbe Bay are unable to adapt genetically to habitat changes and renew their population. The quality of the anemone providing a home to the fish is crucial to its survival, highlighting the urgent need for conservation efforts to protect these marine species.
Biologists at UC Davis propose that species pay attention to each other, especially if they share predators, leading to new insights into population dynamics and cooperation. Advances in technology have made it easier to study short-lived interactions between species in the wild.
A new study reveals that coastal birds can survive hurricanes due to their ability to absorb impacts and recover quickly from storms. Despite being symbols of vulnerability, many populations can be quite resilient to big disturbances.
Researchers used electronic tags to monitor blue and fin whales' feeding behaviors over multiple weeks, providing unprecedented detail about their daily feeding patterns. The study found that both species have similar feeding bout characteristics, with slight differences observed between males and females.
The hoary bat population is declining at a rate that suggests the species is in jeopardy in the Pacific Northwest. The study found evidence of decline for the hoary bat, but not for the little brown bat, which has been heavily impacted by white-nose syndrome.
Scientists analyzed nearly five decades of data on over 5,800 saguaros to predict how the desert species will fare in hotter climates. They found that small variations in topography can buffer saguaro populations from harsh conditions.
A new study from Iowa State University analyzed decades of data on painted turtle populations and found a wide variation in temperature sensitivity within local populations, defying theoretical expectations. The findings suggest that temperature-dependent sex determination may be more resilient to changes in temperature than previously...
A new article connects future population growth, agricultural development and infectious disease, highlighting the need for balance in agriculture to prevent disease outbreaks. Solutions proposed include improving hygiene, genetic variability, education, and predictive models.
Researchers found a significant increase in the number of leatherback nests in Espírito Santo, Brazil, from 25.6 to 89.8 between 1988 and 2017. The gentle recovery is attributed to local conservation efforts, but the population still faces threats from climate change, pollution, and coastal development.
Researchers used sophisticated modelling to determine the likely routes travelled by Aboriginal people tens of thousands of years ago and the sizes of groups required for survival. The simulations indicate that at least 1300 people arrived in a single migration event or smaller waves, averaging 130 people every 70 years over 700 years.
A team of life scientists at UCLA discovered that sea otters have low genetic diversity, which could endanger their health. The researchers found evidence of potentially harmful genetic variation and mating between closely related ancestors in the sea otter genome, similar to other endangered species with small population sizes.
Researchers developed a new approach to estimate population abundance from simultaneous counts of unmarked individuals over multiple sites. The methodology works best in scenarios with few sites, large variation in abundance among sites, and individuals moving between sampling sites.
A recent study by Imperial College London found that birds living near the edge of their range are more sensitive to deforestation than those closer to their core habitat. The research analyzed 378 bird species across 211 sites in Brazil's Atlantic Forest, revealing dramatic differences in sensitivity to habitat loss.
Researchers analyzed DNA from 763 individuals across the region, finding three distinct east-west genetic groupings correlating with ecological zones. The study reveals previously unknown genetic connections and shifts in ancestry over time, shedding light on human migration and cultural transfer in inner Eurasia.
Research reveals that pika populations decline at lower elevations with high vapor-pressure deficit, while mid-elevation pikas face cold stress. High-elevation pikas thrive with sufficient snow cover, promoting healthy reproduction and population growth.
A study by University of Washington researchers reveals that rising single male Magellanic penguins are a result of higher juvenile female mortality and population decline. The data suggests that protecting the penguins' food supply during non-breeding seasons is crucial for conservation.
Researchers found that some frog species persist despite infection, attributed to eco-evolutionary rescue. This occurs when ecological and evolutionary mechanisms allow for host-pathogen coexistence, including immune adaptation and reduced transmission rates. The study provides a glimpse of hope for amphibian populations threatened by Bd.
The University of Texas at San Antonio has received a three-year, $500,000 National Science Foundation award to develop an innovative graduate education model for training diverse student populations in environmental science and ecology. The program, ASSIST, will provide holistic mentoring, scientific writing, and public science commun...
Researchers at the University of Sydney discovered six termite populations in Japan that lacked males, yet still reproduced. These findings suggest asexual reproduction may be essential for some advanced animal populations to adapt to new environments.
Researchers at the University of Kansas found that a recent large-scale analysis of population density was flawed due to biased sampling and missing data. Their study highlights the need to consider additional factors beyond geographic range and environmental niches when studying species abundance.
A new grant will support research on intermittent, or not continuously flowing, streams across the southern United States. The project aims to understand how climate and biological factors affect stream ecosystems when they dry, and develop a large-scale framework to analyze environmental changes.
Researchers found that martens on Isle Royale were genetically linked to populations in Ontario, suggesting they arrived in the 1990s. The population's low genetic diversity indicated a severe bottleneck, with estimates suggesting two individuals repopulated the island just before their reappearance in 1993.
The Isle Royale wolf population has remained steady at two individuals for the third consecutive year, with the moose population continuing to grow above historic averages. The study's citizen science volunteers have contributed significantly to the research efforts, gathering data on moose skull sizes and wolf activity.
Researchers investigate how populations across different locations respond to environmental changes, aiming to improve fisheries management and conservation. By analyzing hierarchical dynamical systems, the study sheds light on species populations and predicts factors that increase the risks of extinction.
Researchers found that changing water temperature and algal blooms affected sea urchin populations, leading to abnormal development of their larvae. The study provides valuable insights into the importance of long-term monitoring for detecting ecological changes and understanding their causes.
Brown bears may fall into evolutionary and ecological traps due to poor decision-making on environmental cues, leading to declines in population. The article proposes mechanisms by which these traps can affect brown bear dynamics and viability in human-modified landscapes.
A study published in PLOS ONE found that US National Parks are essential for bird conservation in a changing climate. By 2041-2070, the average park is expected to support 29% more species in winter and 6% more species in summer.
A recent expedition using satellite imagery and quadcopter-based aerial photography revealed the Danger Islands have over 751,527 pairs of Adélie penguins, making them the third and fourth largest colonies worldwide. The discovery sheds light on how climate change affects this species, with potential implications for conservation efforts.
A new study led by researchers from the Woods Hole Oceanographic Institution has discovered a supercolony of over 1.5 million Adélie penguins in the Danger Islands, off the Antarctic Peninsula's northern tip. The population appears to be resilient to climate change, providing valuable insights for future monitoring and conservation eff...
A Michigan State University study reveals that the endangered piping plover population may decline over the next decade due to increasing predator pressure. The researchers developed an integrated population model coupled with a Bayesian population viability analysis to improve accuracy in forecasting population changes.
Researchers used carbon isotopes to track shark feeding habits, finding that coastal sharks forage in a range of coastal food webs, while deeper ocean sharks rely on specific areas of colder water. The findings may help conservationists design more effective protection strategies for declining shark populations.
A University of Colorado Boulder-led study confirms that climate factors limit species expansion in stressful environments, but interactions with other species play a crucial role in shaping range limits. The researchers found that stress impacts plant growth, survival, reproduction, and germination, which drives the pattern.
A 40-year study on Isle Royale moose reveals a 16% decline in skull size, indicating smaller individuals and shorter lives, likely linked to climate warming. The population's growth may be an imbalance in the predator-prey dynamics, with wolves' decline contributing to malnutrition.
The study reveals that the Sumatran rhinoceros population declined significantly around the middle of the Pleistocene, approximately one million years ago, due to climate change and habitat loss. The effective population size was reduced from an estimated 57,800 individuals to just 700 by 9,000 years ago.
A new study sheds light on the source and spread of the white-nose syndrome fungus, which has wiped out millions of bats in North America. Researchers found that the fungus was introduced to North America from Europe and has since spread rapidly due to the effective dispersal abilities of bats.
Researchers tracked individual albatrosses for their entire lives to identify intrinsic quality that drives performance, including reproductive success and longevity. The study found that birds born in warmer years were smaller and performed poorly, while those from denser populations had reduced success.
A genomic study of Scandinavian wolves has found extensive inbreeding, with some individuals having entire chromosomes without genetic variation. The study also revealed that immigrant wolves were partly inbred, contradicting the assumption of unrelated founders.
A new version of Markowitz's portfolio theory predicts inflated growth and reduced volatility in diverse populations across the landscape. It was developed by Prof Cang Hui and colleagues to quantify population demographics and behavior in invasive species management.
A Penn State study found that glow sticks can greatly increase amphibian captures by up to six times, making it a more efficient and cost-effective method. The researchers used glow sticks to lure adult salamanders and frogs into traps set in vernal pools, resulting in a significant capture rate.