Ten years of the resource-based habitat paradigm: the biotope-habitat issue and implications for conserving butterfly diversity

2014 ◽  
Vol 2 (8) ◽  
pp. 1 ◽  
Author(s):  
Roger L. H. Dennis ◽  
Leonardo Dapporto ◽  
John W. Dover
Keyword(s):  
Population Size ◽  
Basic Problem ◽  
Population Distribution ◽  
Range Size ◽  
Population Status ◽  
Population Changes ◽  
Butterfly Diversity ◽  
The Status ◽  
Species Evolution ◽  
Habitat Parameters

The widely used term ‘habitat’ underlies all aspects of a species’ (and community’s) population size, consequently population changes, distribution and range size and changes; ultimately, habitat parameters determine the status of species, whether thriving or threatened with extinction. Habitat parameters also lie at the root of species’ evolution (speciation) involving cycles of resource specialism/generalism. A basic problem is that habitat has long been treated as synonymous with biotope. But, the two variable terms habitat and biotope describe very different phenomena and we make a case for clarity in the use of the term ‘habitat’, especially when the focus is conserving biodiversity. In this review, in reference to butterflies, we distinguish habitat from biotope as a real, grounded resources-based and conditions-based entity, and explain how usage of the terms greatly affects our perception of population status, and of population, distribution, range and speciation processes, central to conserving biodiversity.

scholarly journals Alternative method for assessment of southwestern Atlantic humpback whale population status

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259541
Author(s):  
Guilherme A. Bortolotto ◽  
Len Thomas ◽  
Philip Hammond ◽  
Alexandre N. Zerbini
Keyword(s):  
Population Size ◽  
Carrying Capacity ◽  
Scientific Uncertainty ◽  
Base Case ◽  
Population Status ◽  
Case Scenario ◽  
Alternative Method ◽  
Animal Populations ◽  
The Status ◽  
Status Assessment

The population of humpback whales (Megaptera novaeangliae) wintering off eastern South America was exploited by commercial whaling almost to the point of extinction in the mid-twentieth century. Since cessation of whaling in the 1970s it is recovering, but the timing and level of recovery is uncertain. We implemented a Bayesian population dynamics model describing the population’s trajectory from 1901 and projecting it to 2040 to revise a previous population status assessment that used Sampling-Importance-Resampling in a Bayesian framework. Using our alternative method for model fitting (Markov chain Monte Carlo), which is more widely accessible to ecologists, we replicate a “base case scenario” to verify the effect on model results, and introduce additional data to update the status assessment. Our approach allowed us to widen the previous informative prior on carrying capacity to better reflect scientific uncertainty around historical population levels. The updated model provided more precise estimates for population sizes over the period considered (1901–2040) and suggests that carrying capacity (K: median 22,882, mean 22,948, 95% credible interval [CI] 22,711–23,545) and minimum population size (N1958: median 305, mean 319, 95% CI 271–444) might be lower than previously estimated (K: median 24,558, mean 25,110, 95% CI 22,791–31,118; N1958: median 503, mean 850, 95% CI 159–3,943). However, posterior 95% credible intervals of parameters in the updated model overlap those of the previous study. Our approach provides an accessible framework for investigating the status of depleted animal populations for which information is available on historical mortality (e.g., catches) and intermittent estimates of population size and/or trend.

scholarly journals The wildcat Felis silvestris in northern Turkey: assessment of status using camera trapping

Oryx ◽  
2011 ◽  
Vol 45 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Özgün Emre Can ◽  
İrfan Kandemi̇r ◽  
İnci̇ Togan
Keyword(s):  
Population Size ◽  
Camera Traps ◽  
Sampling Effort ◽  
Felis Silvestris ◽  
Forest Patch ◽  
Western Turkey ◽  
Lack Of Information ◽  
The Status ◽  
Capture Recapture ◽  
Estimate Population Size

AbstractThe wildcat Felis silvestris is a protected species in Turkey but the lack of information on its status is an obstacle to conservation initiatives. To assess the status of the species we interviewed local forestry and wildlife personnel and conducted field surveys in selected sites in northern, eastern and western Turkey during 2000–2007. In January–May 2006 we surveyed for the wildcat using 16 passive infrared-trigged camera traps in Yaylacı k Research Forest, a 50-km2 forest patch in Yenice Forest in northern Turkey. A total sampling effort of 1,200 camera trap days over 40 km2 yielded photo-captures of eight individual wildcats over five sampling occasions. Using the software MARK to estimate population size the closed capture–recapture model M0, which assumes a constant capture probability among all occasions and individuals, best fitted the capture history data. The wildcat population size in Yaylacı k Research Forest was estimated to be 11 (confidence interval 9–23). Yenice Forest is probably one of the most important areas for the long-term conservation of the wildcat as it is the largest intact forest habitat in Turkey with little human presence, and without human settlements, and with a high diversity of prey species. However, it has been a major logging area and is not protected. The future of Yenice Forest and its wildcat population could be secured by granting this region a protection status and enforcing environmental legislation.

scholarly journals Population status of Heritiera fomes Buch.-Ham., a threatened species from Mahanadi Mangrove Wetland, India

2021 ◽  
Vol 13 (12) ◽  
pp. 19791-19798
Author(s):  
Sudam Charan Sahu ◽  
Manas Ranjan Mohanta ◽  
N.H. Ravindranath
Keyword(s):  
Natural Populations ◽  
P Value ◽  
Population Status ◽  
Mangrove Species ◽  
Sea Levels ◽  
Excoecaria Agallocha ◽  
Mangrove Wetland ◽  
Heritiera Fomes ◽  
The Status ◽  
Rising Sea Levels

Heritiera fomes Buch.-Ham. is assessed as an endangered mangrove species by IUCN, and information on population status is lacking. The present study assesses the status of H. fomes in Mahanadi Mangrove Wetland on the east coast of India. Three forest blocks were selected and sampled for this study. Among these, the mean girth at breast height (GBH) of H. fomes was the highest in Hetamundia (HD) forest block. GBH of H. fomes was inversely proportional to the cumulative disturbance index (R2= 0.7244, p value <0.005). The relative density was maximum for H. fomes (56%) at Bhitarkharnasi (BK), and for Excoecaria agallocha at Hetamundia (HD; 35%) & Kansaridia (KD; 54%), respectively. Excoecaria agallocha is a dominant species possibly impacting natural populations of H. fomes. Climate change and rising sea levels may also negatively affect the existence of this species. Therefore, appropriate strategies should be taken for conservation of this globally threatened mangrove species prior to its extinction.

scholarly journals Population centroids of the world administrative units from nighttime lights 1992-2013

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Ola Hall ◽  
Maria Francisca Archila Bustos ◽  
Niklas Boke Olén ◽  
Thomas Niedomysl
Keyword(s):  
Census Data ◽  
Population Distribution ◽  
Local Population ◽  
Population Changes ◽  
Spatial Unit ◽  
The Past ◽  
Nighttime Lights ◽  
The Mean ◽  
Administrative Units ◽  
True Population

Abstract Knowledge about the past, current and future distribution of the human population is fundamental for tackling many global challenges. Censuses are used to collect information about population within a specified spatial unit. The spatial units are usually arbitrarily defined and their numbers, size and shape tend to change over time. These issues make comparisons between areas and countries difficult. We have in related work proposed that the shape of the lit area derived from nighttime lights, weighted by its intensity can be used to analyse characteristics of the population distribution, such as the mean centre of population. We have processed global nighttime lights data for the period 1992–2013 and derived centroids for administrative levels 0–2 of the Database of Global Administrative Areas, corresponding to nations and two levels of sub-divisions, that can be used to analyse patterns of global or local population changes. The consistency of the produced dataset was investigated and distance between true population centres and derived centres are compared using Swedish census data as a benchmark.

Assessing the status of a threatened island endemic, Ctenosaura oedirhina, on Roatán, Honduras

2020 ◽  
Vol 47 (2) ◽  
pp. 137
Author(s):  
A. B. C. Goode ◽  
S. A. Pasachnik ◽  
T. L. Maple
Keyword(s):  
Population Size ◽  
Distance Sampling ◽  
Adult Mortality ◽  
Isolated Populations ◽  
Cultural Traditions ◽  
Island Endemic ◽  
Wild Fauna ◽  
The Status ◽  
In The Wild ◽  
Study Sites

Abstract Context Organisms living in small, isolated populations with very restricted ranges are at high risk of extirpation due to various direct and indirect forces than mainland populations. Roatán spiny-tailed iguanas (Ctenosaura oedirhina) are endemic to the 146-km2 island of Roatán, Honduras. Harvesting for consumption, fragmentation of habitat and predation by domestic animals threaten the existence of this lizard. This species is federally protected in Honduras; however, enforcement is rare. These iguanas are also listed as Endangered by the International Union for Conservation of Nature (IUCN) and are on Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). This species is geographically and genetically isolated into small subpopulations that are declining in density. Aims To estimate the population size of Roatán spiny-tailed iguanas (Ctenosaura oedirhina) on the island of Roatán, Honduras. Methods Distance sampling surveys have been used to monitor this species since 2012, and have been used to determine population density at five study sites. Estimates of density at those sites and across the island were used to calculate the population size of this species. Key results The present study elucidates that the high-density populations remaining are declining. The current population size is estimated to be 3759 (95% CI=1406–12616) individuals within the study sites, with 730 additional iguanas potentially outside of the study sites. Conclusions If the current level of decline continues, this species may become extirpated from some locations on Roatán, and go extinct in the wild. Although Honduras does have laws protecting this species and other wildlife, enforcement must be enhanced. Implications Lack of enforced protection for this species allows poaching for consumption to continue, which has been shown to alter its distribution and cause increased adult mortality. Local customs value the consumption of this species, creating a delicate management situation. Recommendations include strategies that mitigate the threat posed by consumption and increase enforcement of the current laws, while acknowledging cultural traditions.

scholarly journals Mitochondrial DNA Sequence Diversity in Mammals: A Correlation between the Effective and Census Population Sizes

2020 ◽  
Vol 12 (12) ◽  
pp. 2441-2449
Author(s):  
Jennifer James ◽  
Adam Eyre-Walker
Keyword(s):  
Mitochondrial Dna ◽  
Metabolic Rate ◽  
Population Size ◽  
Effective Population Size ◽  
Dna Sequence ◽  
Range Size ◽  
Effective Population ◽  
Population Sizes ◽  
Census Population Size ◽  
The Relationship

Abstract What determines the level of genetic diversity of a species remains one of the enduring problems of population genetics. Because neutral diversity depends upon the product of the effective population size and mutation rate, there is an expectation that diversity should be correlated to measures of census population size. This correlation is often observed for nuclear but not for mitochondrial DNA. Here, we revisit the question of whether mitochondrial DNA sequence diversity is correlated to census population size by compiling the largest data set to date, using 639 mammalian species. In a multiple regression, we find that nucleotide diversity is significantly correlated to both range size and mass-specific metabolic rate, but not a variety of other factors. We also find that a measure of the effective population size, the ratio of nonsynonymous to synonymous diversity, is also significantly negatively correlated to both range size and mass-specific metabolic rate. These results together suggest that species with larger ranges have larger effective population sizes. The slope of the relationship between diversity and range is such that doubling the range increases diversity by 12–20%, providing one of the first quantifications of the relationship between diversity and the census population size.

scholarly journals Challenges of ecological monitoring: estimating population abundance from sparse trap counts

2011 ◽  
Vol 9 (68) ◽  
pp. 420-435 ◽  
Author(s):  
Natalia Petrovskaya ◽  
Sergei Petrovskii ◽  
Archie K. Murchie
Keyword(s):  
Population Size ◽  
Numerical Integration ◽  
Spatial Data ◽  
Population Distribution ◽  
Species Abundance ◽  
Ecological Monitoring ◽  
Field Studies ◽  
Pest Species ◽  
Population Size Estimates ◽  
Size Estimates

Ecological monitoring aims to provide estimates of pest species abundance—this information being then used for making decisions about means of control. For invertebrate species, population size estimates are often based on trap counts which provide the value of the population density at the traps' location. However, the use of traps in large numbers is problematic as it is costly and may also be disruptive to agricultural procedures. Therefore, the challenge is to obtain a reliable population size estimate from sparse spatial data. The approach we develop in this paper is based on the ideas of numerical integration on a coarse grid. We investigate several methods of numerical integration in order to understand how badly the lack of spatial data can affect the accuracy of results. We first test our approach on simulation data mimicking spatial population distributions of different complexity. We show that, rather counterintuitively, a robust estimate of the population size can be obtained from just a few traps, even when the population distribution has a highly complicated spatial structure. We obtain an estimate of the minimum number of traps required to calculate the population size with good accuracy. We then apply our approach to field data to confirm that the number of trap/sampling locations can be much fewer than has been used in many monitoring programmes. We also show that the accuracy of our approach is greater that that of the statistical method commonly used in field studies. Finally, we discuss the implications of our findings for ecological monitoring practice and show that the use of trap numbers ‘smaller than minimum’ may still be possible but it would result in a paradigm shift: the population size estimates should be treated probabilistically and the arising uncertainty may introduce additional risk in decision-making.

Estimating population status under conditions of uncertainty: the Ross seal in East Antarctica

2008 ◽  
Vol 20 (2) ◽  
pp. 123-133 ◽  
Author(s):  
Colin J. Southwell ◽  
Charles G.M. Paxton ◽  
David L. Borchers ◽  
Peter L. Boveng ◽  
Erling S. Nordøy ◽  
...  
Keyword(s):  
Survey Design ◽  
East Antarctica ◽  
Population Status ◽  
Pack Ice ◽  
The Status ◽  
Antarctic Treaty ◽  
Survey Design And Analysis ◽  
The Many ◽  
Many Sources ◽  
The Antarctic

AbstractThe Ross seal (Ommatophoca rossii) is the least studied of the Antarctic ice-breeding phocids. In particular, estimating the population status of the Ross seal has proved extremely difficult. The Protocol on Environmental Protection to the Antarctic Treaty currently designates the Ross seal as a ‘Specially Protected Species’, contrasting with the IUCN's classification of ‘Least Concern’. As part of a review of the Ross seal's classification under the Protocol, a survey was undertaken in 1999/2000 to estimate the status of the Ross seal population in the pack ice off East Antarctica between 64–150°E. Shipboard and aerial sighting surveys were carried out along 9476 km of transect to estimate the density of Ross seals hauled out on the ice, and satellite dive recorders deployed on a sample of Ross seals to estimate the proportion of time spent on the ice. The survey design and analysis addressed the many sources of uncertainty in estimating the abundance of this species in an effort to provide a range of best and plausible estimates. Best estimates of abundance in the survey region ranged from 41 300–55 900 seals. Limits on plausible estimates ranged from 20 500 (lower 2.5 percentile) to 226 600 (upper 97.5 percentile).

A fisheries perspective of behavioural variability: differences in movement behaviour and extraction rate of an exploited sparid, snapper (Pagrus auratus)

2011 ◽  
Vol 68 (4) ◽  
pp. 632-642 ◽  
Author(s):  
Darren M. Parsons ◽  
Mark A. Morrison ◽  
Jeremy R. McKenzie ◽  
Bruce W. Hartill ◽  
Richard Bian ◽  
...  
Keyword(s):  
Population Size ◽  
Fisheries Management ◽  
Fishing Effort ◽  
Extraction Rate ◽  
Movement Behaviour ◽  
Pagrus Auratus ◽  
The Status ◽  
Likelihood Model ◽  
Lower Population ◽  
Fishery Species

Intraspecific variation in movement patterns are well established for many species, but poorly appreciated in fisheries management. In this study we dart-tagged snapper ( Pagrus auratus ), an important fishery species, across different areas and habitats in the Hauraki Gulf, New Zealand. Tag returns were used to quantify movement behaviour and extraction rates using a maximum likelihood model that corrected for spatial variability in population size and fishing effort. Residency was high (~90%) in two strata and lower (75%) in the remaining stratum. The stratum with the highest residency also appeared to experience the highest extraction rate (likely due to a lower population size). These results confirm the existence of differences in movement behaviour within the snapper population, suggesting that localized areas may become depleted regardless of the status of the overall stock. This has consequences for the scale of fisheries management and the size of marine reserves implemented in different regions. Understanding why variation in movement behaviour exists (i.e., genetic vs. environmental) is the next step in addressing the influence of animal behaviour on fisheries management.

The limiting properties of population distributions with particular application to manpower planning

1983 ◽  
Vol 20 (1) ◽  
pp. 19-30 ◽  
Author(s):  
Mark Woodward
Keyword(s):  
Population Size ◽  
Stable Distribution ◽  
Population Distribution ◽  
Manpower Planning ◽  
Expected Value ◽  
Practical Applications ◽  
Population Distributions ◽  
Number Of Classes

A model for predicting expected-value population distributions is developed, assuming that all movements are Markovian and time-homogeneous. Each individual is classified by the amount of time he has spent in the population and by which of a number of classes, of an unspecified nature, he inhabits. The limiting properties of the population distribution are derived, and, in particular, conditions for convergence to a stable distribution are given.Some discussion of the relevance of the theory to practical applications is given, primarily to manpower planning when recruitment occurs purely to maintain a specified overall population size.

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