Demography of Zenaida Doves in Puerto Rico

Abstract We conducted a capture-recapture study of Zenaida Doves (Zenaida aurita) in three neighboring dairy farms in eastcentral Puerto Rico during 1984–1997. During 46 sampling periods, mean survival rate per sampling period was 0.77 (range = 0.1–1.0), mean recruitment was 911 individuals (range = 182–5,124), and mean population size was 1,569 individuals (range = 233–7,354). Survival increased during 1984–1991 and decreased during 1992–1997. Recruitment did not show a trend, but population size increased during 1984–1997. Rate of increase was a curvilinear decreasing function of population size. A demographic model with a fixed mortality rate stabilized at 1,350 individuals. When mortality rate was defined as a normal random variable, mean population size was 1,421 individuals, and there was a 0.95 probability of observing population sizes from 467 to 2,375 individuals. The size of the Zenaida Dove population varied widely over time, but periods of high recruitment rapidly offset periods of low survival in the dairy farms.

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Effects of goldfish (Carassius auratus) population size and body condition on the transmission of Gyrodactylus kobayashii (Monogenea)

Parasitology ◽

10.1017/s0031182017000543 ◽

2017 ◽

Vol 144 (9) ◽

pp. 1221-1228 ◽

Cited By ~ 3

Author(s):

SHUN ZHOU ◽

HONG ZOU ◽

SHAN G. WU ◽

GUI T. WANG ◽

DAVID J. MARCOGLIESE ◽

...

Keyword(s):

Population Size ◽

Body Condition ◽

Host Density ◽

Host Population ◽

Laboratory Model ◽

Constant Density ◽

Contact Rates ◽

Effective Contact ◽

Rate Of Increase ◽

Population Sizes

SUMMARYField surveys indicate that host population size, rather than density, is the most important determinant of monogenean infection dynamics. To verify this prediction, epidemic parameters were monitored for 70 days at five host population sizes held at constant density using a goldfish – Gyrodactylus kobayashii laboratory model. During the first 20 days, the rate of increase of prevalence and mean abundance was faster in small host populations. Total mean prevalence and total mean abundance throughout the experiment were not significantly affected by host population sizes. Higher transmission rates were detected in larger host populations. However, there were no significant differences in effective contact rates among the five host populations on each sampling day during the first 20 days, implying that contact rates may be saturated at a sufficiently high host density. These results demonstrate that the epidemic occurs more quickly in smaller host populations at the beginning of the experiment. However, the epidemic is independent of the host population size due to the similar effective contact rates in the five population sizes. Significant negative influence of the initial body condition (Kn) of uninfected goldfish on total mean abundance of parasites suggests that susceptibility of hosts is also a determinant of parasite transmission.

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A Simulation Study on Increasing Capture Periods in Bayesian Closed Population Capture-Recapture Models with Heterogeneity

Journal of Modern Applied Statistical Methods ◽

10.22237/jmasm/1556668920 ◽

2020 ◽

Vol 18 (1) ◽

pp. 2-23

Author(s):

Ross M. Gosky ◽

Joel Sanqui

Keyword(s):

Population Size ◽

Simulation Study ◽

Simulated Data ◽

Population Models ◽

Data Set ◽

Closed Population ◽

Population Sizes ◽

Capture Recapture

Capture-Recapture models are useful in estimating unknown population sizes. A common modeling challenge for closed population models involves modeling unequal animal catchability in each capture period, referred to as animal heterogeneity. Inference about population size N is dependent on the assumed distribution of animal capture probabilities in the population, and that different models can fit a data set equally well but provide contradictory inferences about N. Three common Bayesian Capture-Recapture heterogeneity models are studied with simulated data to study the prevalence of contradictory inferences is in different population sizes with relatively low capture probabilities, specifically at different numbers of capture periods in the study.

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Using visual encounter data to improve capture-recapture abundance estimates

10.1101/2020.01.22.915314 ◽

2020 ◽

Author(s):

Maxwell B. Joseph ◽

Roland A. Knapp

Keyword(s):

Population Size ◽

Lower Bounds ◽

Bayesian Approach ◽

Individual Identification ◽

Hierarchical Bayesian ◽

Sampling Occasion ◽

Demographic Rates ◽

Abundance Estimates ◽

Population Sizes ◽

Capture Recapture

AbstractCapture-recapture studies are widely used in ecology to estimate population sizes and demographic rates. In some capture-recapture studies, individuals may be visually encountered but not identified. For example, if individual identification is only possible upon capture and individuals escape capture, visual encounters can result in failed captures where individual identities are unknown. In such cases, the data consist of capture histories with known individual identities, and counts of failed captures for individuals with unknown identities. These failed captures are ignored in traditional capture-recapture analyses that require known individual identities. Here we show that if animals can be encountered at most once per sampling occasion, failed captures provide lower bounds on population size that can increase the precision of abundance estimates. Analytical results and simulations indicate that visual encounter data improve abundance estimates when capture probabilities are low, and when there are few repeat surveys. We present a hierarchical Bayesian approach for integrating failed captures and auxiliary encounter data in statistical capture-recapture models. This approach can be integrated with existing capture-recapture models, and may prove particularly useful for hard to capture species in data-limited settings.

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Estimating the population size of people who inject drugs in Ho Chi Minh City, Vietnam: A two-survey capture-recapture exercise (Preprint)

10.2196/preprints.16459 ◽

2019 ◽

Author(s):

Abu Abdul-Quader

Keyword(s):

Population Size ◽

Illicit Drugs ◽

People Who Inject Drugs ◽

Care Service ◽

Ho Chi Minh City ◽

Size Estimation ◽

Population Size Estimates ◽

Capture Recapture ◽

The City ◽

Size Estimates

BACKGROUND Population size estimation of people who inject drugs (PWID) in Ho Chi Minh City (HCMC), Vietnam relied on the UNAIDS Estimation and Projection Package and reports from the city police department. The two estimates vary widely. OBJECTIVE To estimate the population size of people who inject drugs in Ho Chi Minh City, Vietnam METHODS Using Respondent-driven sampling (RDS), we implemented two-source capture-recapture method to estimate the population size of PWID in HCMC in 2017 in 7 out of 24 districts. The study included men or women aged at least 18 years who reported injecting illicit drugs in the last 90 days and who had lived in the city the past six months. We calculated two sets of size estimates, the first assumed that all participants in each survey round resided in the district where the survey was conducted, the second, used the district of residence as reported by the participant. District estimates were summed to obtain an aggregate estimate for the seven districts. To calculate the city total, we weighted the population size estimates for each district by the inverse of the stratum specific sampling probabilities. RESULTS The first estimate resulted in a population size of 19,155 (95% CI: 17,006–25,039). The second one generated a smaller population size estimate of 12,867 (95% CI: 11,312–17,393). CONCLUSIONS The two-survey capture-recapture exercise provided two disparate estimates of PWID in HCMC. For planning HIV prevention and care service needs among PWID in HCMC, both estimates may need to be taken into consideration together with size estimates from other sources.

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Effect of Pheromone Blend Components, Sex Ratio, and Population Size on the Mating of Cadra cautella (Lepidoptera: Pyralidae)

Journal of Insect Science ◽

10.1093/jisesa/ieaa128 ◽

2020 ◽

Vol 20 (6) ◽

Author(s):

Abeysinghe Mudiyanselage Prabodha Sammani ◽

Dissanayaka Mudiyanselage Saman Kumara Dissanayaka ◽

Leanage Kanaka Wolly Wijayaratne ◽

William Robert Morrison

Keyword(s):

Sex Ratio ◽

Population Size ◽

Management Practices ◽

Mating Disruption ◽

Current Knowledge ◽

Mating Status ◽

Cadra Cautella ◽

Synthetic Chemicals ◽

Population Sizes ◽

Lepidoptera Pyralidae

Abstract The almond moth Cadra cautella (Walker), a key pest of storage facilities, is difficult to manage using synthetic chemicals. Pheromone-based management methods remain a high priority due to advantages over conventional management practices, which typically use insecticides. Cadra cautella females release a blend of pheromone including (Z, E)-9,12-tetradecadienyl acetate (ZETA) and (Z)-9-tetradecadien-1-yl acetate (ZTA). The effect of these components on mating of C. cautella and how response varies with the population density and sex ratio remain unknown. In this study, the mating status of C. cautella was studied inside mating cages under different ratios of ZETA and ZTA diluted in hexane and at different population sizes either with equal or unequal sex ratio. The lowest percentage of mated females (highest mating disruption [MD] effects), corresponding to roughly 12.5%, was produced by a 5:1 and 3.3:1 ratio of ZETA:ZTA. Populations with equal sex ratio showed the lowest percentage of mated females, at 20% and 12.5% under lower and higher density, respectively. The next lowest percentage of mated females was produced when the sex ratio was set to 1: 2 and 2:1 male:female, with just 25% and 22.5% of moths mated, respectively. This study shows that mating status of C. cautella is influenced by ZETA:ZTA ratio, sex ratio, and population size. This current knowledge would have useful implications for mating disruption programs.

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EFFECTS OF POPULATION SIZE AND SELECTION INTENSITY ON SHORT-TERM RESPONSE TO SELECTION FOR POSTWEANING GAIN IN MICE

Genetics ◽

10.1093/genetics/73.3.513 ◽

1973 ◽

Vol 73 (3) ◽

pp. 513-530

Author(s):

J P Hanrahan ◽

E J Eisen ◽

J E Legates

Keyword(s):

Population Size ◽

Selection Response ◽

Selection Intensity ◽

Realized Heritability ◽

Family Selection ◽

Effective Population ◽

Population Sizes ◽

Selection For ◽

Selection Intensities ◽

Term Response

ABSTRACT The effects of population size and selection intensity on the mean response was examined after 14 generations of within full-sib family selection for postweaning gain in mice. Population sizes of 1, 2, 4, 8 and 16 pair matings were each evaluated at selection intensities of 100% (control), 50% and 25% in a replicated experiment. Selection response per generation increased as selection intensity increased. Selection response and realized heritability tended to increase with increasing population size. Replicate variability in realized heritability was large at population sizes of 1, 2 and 4 pairs. Genetic drift was implicated as the primary factor causing the reduced response and lowered repeatability at the smaller population sizes. Lines with intended effective population sizes of 62 yielded larger selection responses per unit selection differential than lines with effective population sizes of 30 or less.

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On a model for a fair distribution of gifts

Journal of Applied Probability ◽

10.2307/3212232 ◽

1971 ◽

Vol 8 (4) ◽

pp. 681-690

Author(s):

János Galambos

Keyword(s):

Foreign Aid ◽

Population Size ◽

Random Variable ◽

Fair Distribution ◽

To Receive

A number of items are to be distributed among n individuals, arranged in a line and labelled by the integers 1, 2, ···, n, in such a way that the distance between any two members presented should be at least d, a given number, but otherwise any subset of the population should have the same probability of each of its members being presented. The number of items thus distributed is a random variable X(d, n) and it turns out that X(d, n) is asymptotically a fixed percentage of the population size n. This fact makes it possible to apply the model in a number of situations. For example, if in a foreign aid program a number of tools are offered and to be distributed in a fair way but, for lack of sufficient quantity, one tool is expected to be used by a number of neighbours, the model is applicable if the amount of aid is not fixed in advance but may vary within certain limits. A similar situation arises in cases of disaster (floods, earthquakes, etc.) when the victims are sent gifts, again in an insufficient quantity, hence for the sake of justice, a family of a smaller size is supposed to receive only one gift. In many other similar cases, the model can be used.

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

Oryx ◽

10.1017/s0030605310001328 ◽

2011 ◽

Vol 45 (1) ◽

pp. 112-118 ◽

Cited By ~ 11

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.

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Estimation of Catchabilities and Population Sizes of Lobsters

Journal of the Fisheries Research Board of Canada ◽

10.1139/f63-006 ◽

1963 ◽

Vol 20 (1) ◽

pp. 59-88 ◽

Cited By ~ 26

Author(s):

J. E. Paloheimo

Keyword(s):

Environmental Factors ◽

Population Size ◽

Atlantic Coast ◽

Temperature Data ◽

New Method ◽

Bottom Temperature ◽

Population Size Estimates ◽

Population Sizes ◽

Estimate Population Size ◽

Size Estimates

Techniques of estimating population size, level of fishing, and the degree of dependence of fishing success on environmental factors are examined on the basis of tagging, catch and effort data. A new method is developed to estimate population size from catch, effort, and temperature data when the catchability varies with temperature.The methods of estimation discussed are applied to data collected from a number of lobster fisheries on Canada's Atlantic coast. Analysis confirms a relationship between the catchability of lobsters and bottom temperature. Differences in this relationship are found between areas and between tagged and untagged lobsters within areas. It is suggested that these differences are attributable to the differences in densities as well as to aggregations of lobsters and fishing. The effect of these aggregations on population size estimates is considered.Calculated average catchabilities at comparable temperatures are different for different areas. These differences are correlated with the numbers of trap hauls per day per square miles fished. It is suggested that the differences in the catchabilities might be due to interactions between units of gear not predicted by the customary relationship between catch and effort.

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