Long-term trends in the abundance and breeding performance in Adélie penguins:the Argentine Ecosystem Monitoring Program

In this work,we report long-term trends in the abundance and breeding performance of Adélie penguins(Pygoscelis adeliae)nesting in three Antarctic colonies(i.e.,at Martin Point,South Orkneys Islands;Stranger Point/Cabo Funes,South Shetland Islands;and Esperanza/Hope Bay in the Antarctic Peninsula)from 1995/96 to 2022/23.Using yearly count data of breeding groups selected,we observed a decline in the number of breeding pairs and chicks in crèche at all colonies studied.However,the magnitude of change was higher at Stranger Point than that in the remaining colonies.Moreover,the index of breeding success,which was calculated as the ratio of chicks in crèche to breeding pairs,exhibited no apparent trend throughout the study period.However,it displayed greater variability at Martin Point compared to the other two colonies under investigation.Although the number of chicks in crèche of Adélie penguins showed a declining pattern,the average breeding performance was similar to that reported in gentoo penguin colonies,specifically,those undergoing a population increase(even in sympatric colonies facing similar local conditions).Consequently,it is plausible to assume a reduction of the over-winter survival as a likely cause of the declining trend observed,at least in the Stranger Point and Esperanza colonies.However,we cannot rule out local effects during the breeding season affecting the Adélie population of Martin Point.

Spatial Pattern of Long-term Residence in the Urban Floating Population of China and its Influencing Factors

Exploring long-term residence among the urban floating population is crucial to understanding urban growth in China,particularly since the 2008 financial crisis.By using China Migrants Dynamic Survey data for 2012–2014,China Labor-force Dynamics Survey data for 2014–2016,and macroscale urban matched data,we analyzed the spatial pattern of long-term residential behavior in China’s urban floating population in 2012–2016 and developed an urban spatial utility equilibrium model containing‘macro’urban factors and‘micro’individual and household factors to explain the pattern.The results first revealed that long-term residence is defined as≥6 yr for the urban floating population in China.Second,members of this population are more likely to be long-term residents of the megacities in the three urban agglomerations in eastern China as well as of small and medium-sized cities in western and northeastern China,whereas short-term residence is more likely in cities in central China and near the three urban agglomerations.Third,urban population density and housing prices,both have a significant U-shaped effect,are main factors affecting the spatial pattern of long-term residence.

Influencing Factors of Long-Term Residence Intention of Highly Educated Inter-Provincial and Intra-Provincial Floating Population From the Perspective of Social Integration:Take Guangdong Province for Example

Floating population plays an important role in the development of cities,regions,and countries.The economic growth path with Guangdong characteristics is inseparable from the support of highly educated groups.Studying the long-term residence intention of the highly educated floating population is helpful for the city to attract and retain talents.From the perspective of social integration,using CMDS 2017 data and taking Guangdong Province for example,this paper studies the influencing factors of long-term residence intention through SPSS logistic regression,taking intra-provincial and inter-provincial floating population with a bachelor’s degree or above as sample.The main conclusions are:(1)Marital and childbearing status is the primitive influencing factor of long-term residence intention among intra-provincial and inter-provincial floating population.Samples with high income,under social insurance system,being female and having non-agricultural hukou,are tend to prefer long-term residence.Samples who connect with the locals and participate in social public welfare are more likely to stay.(2)Personal age and city livability have a significant positive impact on the long-term residence intention of the inter-provincial highly educated floating population,but agricultural hukou and self-employed laborer status will weaken the long-term residence intention of this group.(3)Participation in townsmen/alumni association has a positive effect on the long-term residence intention of the intra-provincial highly educated floating population,and connection with outlanders also promotes the long-term residence intention of this group.(4)The long-term residence intention of inter-provincial highly educated floating population is usually based on reality,therefore they pay more attention to the development,changes,and livability of the destination city.However,the long-term residence intention of intra-provincial highly educated floating population is usually based on perception,so they pay more attention to whether they like the city.Compared with intra-provincial flows,inter-provincial flows have higher economic and emotional migration costs,more institutional barriers,and more life adaptation problems.Therefore,the government should introduce targeted measures to promote social integration and improve long-term residence intention.

Building Long-Term Care Insurance System in China

The objective is to explore the foundation of the elderly long-term care insurance system in China, which is to face the problem resulted from aging of the population. Adopting the contrastive analysis to introduce briefly the long-term care insurance system in German, Japan and America for our learning. Therefore, China＇s long-term care insurance system could not totally indiscriminately imitate the mandatory long-term care insurance system in German and Japan, it also could not copy the business model of nursing insurance system in America. The conclusion is that long-term care insurance system in China should use the experience of developed countries based on the basic national conditions, doing some relative works, such as establishing policies and regulations, strengthening personnel training, and improving the market specification.

Long-term and monthly changes in abundance,size composition and spatial distribution of the mantis shrimp Oratosquilla oratoriainthe BohaiSea

With the decline in fish resources worldwide,the ecological dominance and economic importance of crustaceans have obviously increased.Among crustacean species,mantis shrimps are increasingly dominant in many coastal waters of the world.In China,Oratosquilla oratoria is the most widely distributed and productive species of mantis shrimp,and its relative resource density is the highest in the Bohai Sea.In this study,we analysed the long-term and monthly population characteristics of O.oratoria in the Bohai Sea,including its relative resource density,body size and spatial distribution.The results showed that the relative resource density of O.oratoria in the Bohai Sea increased from 3.59 kg/h in 1982 to 14.48 kg/h in 2018,and the percentage of this species that serves as a fishery resource increased from 4.22%in 1982 to 35.27%in 2018,based on the mean relative resource density in May and August.The relative resource density of O.oratoria in the fishing moratorium season from May to August was significantly higher than that in the other months of fishing season,and the relative resource density decreased rapidly after the fishing moratorium ended.The relative resource density of O.oratoria was the highest in summer(August),followed by in autumn(October)and spring(May),and it was the lowest in winter(January).The relative resource density of O.oratoria in the western Bohai Sea was higher than that in the eastern Bohai Sea.The mean body weight of O.oratoria in the Bohai Sea decreased from 21.95 g in 1982 to 14.34 g in 2018,based on the mean body weight in May and August.The body size of O.oratoria in the fishing moratorium season was significantly higher than that in the fishing season,and the body size decreased rapidly after the fishing moratorium ended.Overall,in the context of declining resources of most fishery species,the relative resource density of O.oratoria increased due to its hardiness and adaptability,and its body size decreased under intensive fishing over the past 30 years.The fishing moratorium system had a great influence on the population dynamics of O.oratoria in terms of the relative resource density and body size in the Bohai Sea.

EFFECTS OF A TOXICANT ON A SINGLE-SPECIES POPULATION WITH PARTIAL POLLUTION TOLERANCE IN A POLLUTED ENVIRONMENT

We study a model for the long-term behavior of a single-species population with some degree of pollution tolerance in a polluted environment. The model consists of three ordinary differential equations： one for the population density, one for the amount of toxicant inside the living organisms, and one for the amount of toxicant in the environment. We derive sufficient conditions for the persistence and the extinction of the population depending on the exogenous input rate of the toxicant into the environment and the level of pollution tolerance of the organisms. Numerical simulations are carried out to illustrate our main results.

Impact of climate change on the small mammal community of the Yukon boreal forest

Long-term monitoring is critical to determine the stability and sustainability of wildlife populations,and if change has occurred,why.We have followed population density changes in the small mammal community in the boreal forest of the southern Yukon for 46 years with density estimates by live trapping on 3-5 unmanipulat­ed grids in spring and autumn.This community consists of 10 species and was responsible for 9%of the ener­gy flow in the herbivore component of this ecosystem from 1986 to 1996,but this increased to 38%from 2003 to 2014.Small mammals,although small in size,are large in the transfer of energy from plants to predators and decomposers.Four species form the bulk of the biomass.There was a shift in the dominant species from the 1970s to the 2000s,with Myodes rutilus increasing in relative abundance by 22%and Peromyscus maniculatus decreasing by 22%.From 2007 to 2018,Myodes comprised 63%of the catch,Peromyscus 20%,and Microtus species 17%.Possible causes of these changes involve climate change,which is increasing primary production in this boreal forest,and an associated increase in the abundance of 3 rodent predators,marten(Martes ameri­cana),ermine(Mustela ermine)and coyotes(Canis latrans).Following and understanding these and potential future changes will require long-term monitoring studies on a large scale to measure metapopulation dynamics.The small mammal community in northern Canada is being affected by climate change and cannot remain sta­ble.Changes will be critically dependent on food-web interactions that are species-specific.

Human-induced environmental changes influence habitat use by an ungulate over the long term

Habitat use and preferences may be subject to spatial and temporal changes. However, long-term studies of species-habitat relationships are the exception. In the prese nt research, I on g-term trends in habitat use by an alpine ungulate, the Tatra chamois Rupicapra rupicapra tatrica, were analyzed. We exami ned how envir on mental changes attributable to climate cha nge, removal of sheep, and habituation to hikers, which took place over the last half-century have changed the spatial distribution of animals. Data on the localities of groups sighted between 1957 and 2013 during autumnal population surveys were used to evaluate habitat associations: these were correlated with year, group size, population size, and climatic conditions. The results indicate that the Tatra chamois is tending, over the long term, to lower its altitude of occurrenee, reduce its average distance to hiking trails, and stay less often on slopes with a southerly aspect. These trends are in dependent of group size, population size, and the weather conditions prevailing during observations, though not for altitude, where increases in air temperature are related to finding chamois at higher elevations. The proportion of alpine meadows and slope in the places used by chamois is correlated with population size, while the proportion of areas with trees and/or shrubs is correlated with group size and air temperature, though long-term changes were not evident for these variables. To the best of our knowledge, this work is the first to document Iong-term trends in habitat use by ungulates. It shows that a species' ecology is influe need by huma n-in duced cha nges: abandonment of pasturage, high-mountain tourism, and climate changes, which constitute the most probable reasons for this aspect of behavioral evolution in the Tatra chamois.