scholarly journals Individual and Temporal Variation in Inland Flight Behavior of Marbled Murrelets: Implications for Population Monitoring

The Condor ◽  
2004 ◽  
Vol 106 (2) ◽  
pp. 344-353 ◽  
Author(s):  
M. Zachariah Peery ◽  
Steven R. Beissinger ◽  
Scott H. Newman ◽  
Benjamin H. Becker ◽  
Esther Burkett ◽  
...  
Keyword(s):  
Population Size ◽  
Population Monitoring ◽  
Breeding Population ◽  
Flight Behavior ◽  
Brachyramphus Marmoratus ◽  
Regional Population ◽  
Breeding Condition ◽  
The Mean ◽  
Para Determinar ◽  
Marbled Murrelets

AbstractWe studied the inland flight behavior of 46 radio-marked Marbled Murrelets (Brachyramphus marmoratus) in 2000 and 2001 in central California to determine how the frequency of inland flights varied among individuals and over time. All breeding murrelets regularly flew inland (mean 82% of daily surveys), but we observed considerable variation in the inland flight behavior of non-nesters. Non-nesters that were physiologically in breeding condition (potential breeders) regularly flew inland (90% of individuals; mean 41% of daily surveys), but non-nesters that were not in breeding condition (nonbreeders) rarely flew inland (20% of individuals; mean 1% of daily surveys). The mean percentage of surveys on which individual murrelets flew inland increased from 20% in 2000 to 61% in 2001, which was partly due to an increase in the percentage of breeders from 11% in 2000 to 50% in 2001. The frequency of inland flights was greatest during the incubation and chick- provisioning stages (100% in both stages), and lowest during the pre- and postbreeding stages (70% and 78%, respectively). Although the mean percentage of flights increased dramatically between years, the regional population estimate from at-sea surveys increased only 28% from 496 to 637 individuals during the same period, indicating that monitoring techniques such as radar that count inland flights are more likely to reflect annual variation in breeding effort than changes in regional population size. Moreover, the inland flight behavior of potential breeders indicates that radar surveys will overestimate breeding population size, even though the lack of inland flights by nonbreeders indicates that radar surveys will underestimate regional population size.Variación Individual y Temporal en el Comportamiento de Vuelo Tierra Adentro de Brachyramphus marmoratus: Implicancias para el Monitoreo de PoblacionesResumen. Estudiamos el comportamiento de vuelo tierra adentro de 46 individuos de Brachyramphus marmoratus marcados con radio transmisores durante el 2000 y 2001 en California central para determinar cómo la frecuencia de vuelos tierra adentro varió entre individuos y a lo largo del tiempo. Todos los individuos reproductivos de B. marmoratus volaron regularmente tierra adentro (media 82% de los muestreos diarios), pero observamos considerable variación en el comportamiento de vuelo tierra adentro en los individuos que no nidificaban. Los individuos que no nidificaban pero que se encontraban fisiológicamente en condición reproductiva (reproductores potenciales) volaron regularmente tierra adentro (90% de los individuos; media 41% de los muestreos diarios), pero los individuos que no nidificaban y que no se encontraban en condición reproductiva raramente volaron tierra adentro (20% de los individuos; media 1% de los muestreos diarios). El porcentaje medio de los muestreos en los cuales los individuos de B. marmoratus volaron tierra adentro incrementó de un 20% en el 2000 a un 61% en el 2001, lo que se debió parcialmente a un incremento en el porcentaje de individuos reproductivos de un 11% en el 2000 a un 50% en el 2001. La frecuencia de vuelos tierra adentro fue mayor durante las etapas de incubación y suministro de alimento a los pichones (100% en ambas etapas), y fue menor durante las etapas pre- y post-reproductivas (70% y 78%, respectivamente). Aunque la proporción media de vuelos incrementó dramáticamente entre años, la población regional estimada a partir de muestreos en el mar incrementó sólo 28% de 496 a 637 individuos durante el mismo período, indicando que las técnicas de monitoreo como el radar, que cuentan los vuelos tierra adentro, tienen una mayor probabilidad de reflejar la variación anual en el esfuerzo reproductivo que en los cambios de tamaño poblacional regional. Más aún, el comportamiento de vuelo tierra adentro de los reproductores potenciales indica que los muestreos con radar sobrestimarán el tamaño poblacional reproductivo, a pesar de que la falta de vuelos tierra adentro por parte de individuos no reproductivos indica que los muestreos con radar subestimarán el tamaño poblacional regional.

Population structure of the Sahiwal breed in Pakistan

1995 ◽  
Vol 60 (2) ◽  
pp. 163-168 ◽  
Author(s):  
A. Dahlin ◽  
U. N. Khan ◽  
A. H. Zafar ◽  
M. Saleem ◽  
M. A. Chaudhry ◽  
...  
Keyword(s):  
Population Structure ◽  
Population Size ◽  
Effective Population Size ◽  
Breeding Population ◽  
Effective Population ◽  
Data Set ◽  
Inbreeding Coefficients ◽  
Sahiwal Cows ◽  
The Mean ◽  
Average Population Size

AbstractThe present study was undertaken to assist conservation and improvement schemes in the Sahiwal breed of cattle in Pakistan. A data set, consisting of records of 244 pure Sahiwal breeding bulls and 5247 cows, the latter representing about 80% of all recorded Sahiwal cows in Pakistan born during a period covering about 20 years, was analysed with regard to inbreeding, additive relationships, effective population size and generation intervals. Average inbreeding coefficients of 1224 cows and 49 bulls, for which at least the grandparents and great-grandsires were known, were 0·043 and 0·046, respectively. About two-thirds of the inbreeding was due to matings between animals with parents or grandparents in common. The mean additive relationship among the cows was 0·062, with within-herd averages ranging from 0·087 to 0·358. The average population size in a subdata set of recorded Sahiwal cattle from 1980 to 1984 was 1612, whereas the most likely estimate of the effective population size was about 30 animals for the same active breeding population. The study indicated the immediate need for an active conservation programme whereby the Sahiwal subpopulations of India and Kenya also should be involved.

INDIVIDUAL AND TEMPORAL VARIATION IN INLAND FLIGHT BEHAVIOR OF MARBLED MURRELETS: IMPLICATIONS FOR POPULATION MONITORING

The Condor ◽  
10.1650/7398 ◽  
2004 ◽  
Vol 106 (2) ◽  
pp. 344 ◽  
Author(s):  
M. Zachariah Peery ◽  
Steven R. Beissinger ◽  
Scott H. Newman ◽  
Benjamin H. Becker ◽  
Esther Burkett ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Population Monitoring ◽  
Flight Behavior ◽  
Marbled Murrelets

Breeding to non-breeding population ratio and breeding performance of the globally Endangered Lear’s Macaw Anodorhynchus leari: conservation and monitoring implications

2014 ◽  
Vol 24 (4) ◽  
pp. 466-476 ◽  
Author(s):  
ERICA C. PACÍFICO ◽  
EDUARDO A. BARBOSA ◽  
THIAGO FILADELFO ◽  
KLEBER G. OLIVEIRA ◽  
LUÍS F. SILVEIRA ◽  
...  
Keyword(s):  
Population Size ◽  
Brood Size ◽  
Population Monitoring ◽  
Breeding Population ◽  
Accurate Information ◽  
Breeding Performance ◽  
Breeding Sites ◽  
Breeding Parameters ◽  
Breeding Attempt ◽  
Population Ratio

SummaryLear’s Macaw Anodorhynchus leari is currently listed as “Endangered” by IUCN. Although it only breeds on cliffs at two protected sites in Bahia State, Brazil, there is no accurate information on population parameters such as the number of breeding pairs and their breeding performance. Between 2009 and 2010, we sought to quantify, for the first time, breeding population size and the main breeding parameters for the species in the two known breeding sites, by quantifying the number of active nests and monitoring 75 breeding attempts. Overall, 80% of the breeding attempts were successful with 1.33 (± 0.86 SD) fledglings/breeding attempt (productivity) and 1.67 (± 0.60 SD) fledglings/successful nest (brood size). Breeding success and productivity were higher in 2010, while brood size did not vary between years and breeding sites. By adding 73 estimated nests to the 41 nests monitored, 228 individuals were estimated to be reproductively active in 2010, representing c.20% of the population (1,125 individuals). Given that the species is confined to a single population, further population increases could provoke overcrowding and negative density-dependent effects if it does not expand geographically. Therefore, long-term population monitoring focusing on the fraction of the population that is actually breeding and its breeding performance, rather than solely on the whole population size, is important for a better understanding of the population dynamics and conservation of this species.

Flight energetics of the Marbled Murrelet, Brachyramphus marmoratus

2004 ◽  
Vol 82 (4) ◽  
pp. 644-652 ◽  
Author(s):  
Kyle H Elliott ◽  
Miyako Hewett ◽  
Gary W Kaiser ◽  
Robert W Blake
Keyword(s):  
Predation Rate ◽  
The Other ◽  
Chick Growth ◽  
Brachyramphus Marmoratus ◽  
Marbled Murrelet ◽  
Significant Difference ◽  
Maximum Range ◽  
Flight Energetics ◽  
The Mean ◽  
Marbled Murrelets

We measured flight speeds (n = 3000) of Marbled Murrelet, Brachyramphus marmoratus (J.F. Gmelin, 1789), to determine whether flight speeds of an exceptionably fast bird coincide with the maximum-range speeds (Vmr) predicted by aerodynamic theory. The mean (±SE) speed of 22.6 ± 0.21 m·s–1 was significantly higher than the Vmr predicted by four models, using conventional values for the parasite drag coefficient (CDpar). In order for the Penny cuick model to predict a Vmr of 22 m·s–1, a CDpar of 0.05, which is lower than any previously reported, is necessary; the other models would need to assume even lower values for CDpar. We concluded that the cruising speed of Marbled Murrelets exceeds Vmr. Marbled Murrelets may exceed Vmr as a result of behavioural decisions, and we examined two behavioural hypotheses: that flight speeds exceed Vmr to (1) minimize predation rate and (2) maximize chick growth rate. However, there was no significant difference between flight speeds during high (daylight) and low (darkness) predation periods or between chick-rearing and non-breeding periods. Marbled Murrelets may also appear to fly at a speed that exceeds Vmr because the underlying aerodynamic theory is inaccurate for this species. To examine the reliability of aerodynamic theory for Marble Murrelets, we compared measured wingbeat frequencies (f) to those predicted by Pennycuick's model. The mean f was significantly lower than the fref predicted by Pennycuick's model, and generally, f = 7.9m–0.22 is a better model for auks than Pennycuick's model. In addition, the Strouhal number was particularly low (0.12 ± 0.02). We conclude that the current aerodynamic models are insufficient for an exceptionally fast-flying bird.

scholarly journals A Blue Tit Cyanistes caeruleus population: its recent increase and breeding data

Ornis Svecica ◽  
2012 ◽  
Vol 22 (1–2) ◽  
pp. 19-24
Author(s):  
Karl Gustav Schölin ◽  
Hans Källander
Keyword(s):  
Population Size ◽  
Negative Relationship ◽  
Breeding Population ◽  
Laying Date ◽  
Strongly Correlated ◽  
Blue Tit ◽  
Cyanistes Caeruleus ◽  
South Central ◽  
The Mean ◽  
Blue Tits

Before 1983, Blue Tits Cyanistes caeruleus never made up more than four pairs of the breeding population in a nestbox study carried out in South Central Sweden. From five breeding pairs in 1983, the population increased to 29 pairs in 2007 and remained high to the end of the study in 2011. Mean laying date was strongly correlated with mean April temperature, which increased during 1983–2011. During the same period mean laying date became nearly ten days earlier. Mean clutch size was 9.90 eggs but varied both within and between years and showed a negative relationship to population size. The mean number of fledglings varied strongly between years, partly because of predation but also due to nestling starvation.

scholarly journals Agglomeration economies, congestion diseconomies, and fertility dynamics in a two-region economy

2021 ◽  
Author(s):  
Madoka Muroishi ◽  
Akira Yakita
Keyword(s):  
Population Size ◽  
Stability Condition ◽  
Fertility Rate ◽  
Model Parameters ◽  
Initial Population ◽  
Interregional Migration ◽  
Stable Path ◽  
Regional Population ◽  
Initial Population Size

AbstractUsing a small, open, two-region economy model populated by two-period-lived overlapping generations, we analyze long-term agglomeration economy and congestion diseconomy effects of young worker concentration on migration and the overall fertility rate. When the migration-stability condition is satisfied, the distribution of young workers between regions is obtainable in each period for a predetermined population size. Results show that migration stability does not guarantee dynamic stability of the economy. The stationary population size stability depends on the model parameters and the initial population size. On a stable trajectory converging to the stationary equilibrium, the overall fertility rate might change non-monotonically with the population size of the economy because of interregional migration. In each period, interregional migration mitigates regional population changes caused by fertility differences on the stable path. Results show that the inter-regional migration-stability condition does not guarantee stability of the population dynamics of the economy.

scholarly journals The Ancestry of a Sample of Sequences Subject to Recombination

Genetics ◽  
1999 ◽  
Vol 151 (3) ◽  
pp. 1217-1228 ◽  
Author(s):  
Carsten Wiuf ◽  
Jotun Hein
Keyword(s):  
Genetic Distance ◽  
Population Size ◽  
Upper Bound ◽  
Recombination Rate ◽  
Common Ancestor ◽  
Recent Common Ancestor ◽  
Sequence Length ◽  
Most Recent Common Ancestor ◽  
The Mean ◽  
Mean Time

Abstract In this article we discuss the ancestry of sequences sampled from the coalescent with recombination with constant population size 2N. We have studied a number of variables based on simulations of sample histories, and some analytical results are derived. Consider the leftmost nucleotide in the sequences. We show that the number of nucleotides sharing a most recent common ancestor (MRCA) with the leftmost nucleotide is ≈log(1 + 4N Lr)/4Nr when two sequences are compared, where L denotes sequence length in nucleotides, and r the recombination rate between any two neighboring nucleotides per generation. For larger samples, the number of nucleotides sharing MRCA with the leftmost nucleotide decreases and becomes almost independent of 4N Lr. Further, we show that a segment of the sequences sharing a MRCA consists in mean of 3/8Nr nucleotides, when two sequences are compared, and that this decreases toward 1/4Nr nucleotides when the whole population is sampled. A measure of the correlation between the genealogies of two nucleotides on two sequences is introduced. We show analytically that even when the nucleotides are separated by a large genetic distance, but share MRCA, the genealogies will show only little correlation. This is surprising, because the time until the two nucleotides shared MRCA is reciprocal to the genetic distance. Using simulations, the mean time until all positions in the sample have found a MRCA increases logarithmically with increasing sequence length and is considerably lower than a theoretically predicted upper bound. On the basis of simulations, it turns out that important properties of the coalescent with recombinations of the whole population are reflected in the properties of a sample of low size.

scholarly journals Effective population size: the effects of sex, genotype, and density on the mean and variance of offspring numbers in the flour beetle, Tribolium castaneum

1980 ◽  
Vol 36 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Michael J. Wade
Keyword(s):  
Population Size ◽  
Effective Population Size ◽  
Tribolium Castaneum ◽  
Black Body ◽  
Body Colour ◽  
Effective Population ◽  
Flour Beetle ◽  
Colour Mutant ◽  
Mean And Variance ◽  
The Mean

SUMMARYIn this paper I present the results of an experimental study of the effects of genotype and density on the mean and variance of offspring numbers in both sexes of the flour beetle, Tribolium castaneum. From the observed variance in offspring numbers the effective population size at several different densities is estimated using the methods of Crow & Morton (1955).I found that both the mean and variance of offspring numbers varied with genotype and density. In general, males were more variable in offspring numbers than females and this variability increased with density. Individuals homozygous for the black body colour mutant, b/b, were less variable in offspring numbers than + / + individuals, but the latter produced more offspring at most densities. As density increased, + / + individuals became more variable in offspring numbers whereas b/b individuals were less sensitive in this regard. These findings are discussed in relation to the ecology of selection at the black and closely linked loci.

scholarly journals Design and Validation of Computerized Flight-Testing Systems with Controlled Atmosphere for Studying Flight Behavior of Red Palm Weevil, Rhynchophorus ferrugineus (Olivier)

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2112
Author(s):  
Maged Mohammed ◽  
Hamadttu El-Shafie ◽  
Nashi Alqahtani
Keyword(s):  
Flight Tunnel ◽  
Flight Behavior ◽  
Processing Unit ◽  
Controlled Atmosphere ◽  
Rhynchophorus Ferrugineus ◽  
Data Logging ◽  
Red Palm Weevil ◽  
Flight Testing ◽  
Flight Mill ◽  
The Mean

Understanding the flight characteristics of insect pests is essential for designing effective strategies and programs for their management. In this study, we designed, constructed, and validated the performance of modern flight-testing systems (flight mill and flight tunnel) for studying the flight behavior of red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier) under a controlled atmosphere. The flight-testing mill consisted of a flight mill, a testing chamber with an automatically controlled microclimate, and a data logging and processing unit. The data logging and processing unit consisted of a USB digital oscilloscope connected with a laptop. We used MATLAB 2020A to implement a graphical user interface (GUI) for real-time sampling and data processing. The flight-testing tunnel was fitted with a horizontal video camera to photograph the insects during flight. The program of Image-Pro plus V 10.0.8 was used for image processing and numerical data analysis to determine weevil tracking. The mean flight speed of RPW was 82.12 ± 8.5 m/min, and the RPW stopped flying at the temperature of 20 °C. The RPW flight speed in the flight tunnel was slightly higher than that on the flight mill. The angular deceleration was 0.797 rad/s2, and the centripetal force was 0.0203 N when a RPW tethered to the end of the rotating arm. The calculated moment of inertia of the RPW mass and the flight mill's rotating components was 9.521 × 10−3 N m2. The minimum thrust force needed to rotate the flight mill was 1.98 × 10−3 N. Therefore, the minimum power required to rotate the flight mill with the mean revolution per min of 58.02 rpm was approximately 2.589 × 10−3 W. The designed flight-testing systems and their applied software proved productive and useful tools in unveiling essential flight characteristics of test insects in the laboratory.

scholarly journals Characteristics and Indications of Legal Abortion among the Pregnant Women in Lorestan Province of Iran during 2017–2019

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Zahra Fatemi ◽  
Soheila Akbari
Keyword(s):  
Event Rate ◽  
Cross Sectional Study ◽  
Legal Abortion ◽  
Descriptive Data ◽  
Cross Sectional ◽  
Maternal Characteristics ◽  
Regional Population ◽  
The Mean ◽  
Event Rates ◽  
The Brain

Background. Legal abortion is a challenge from the viewpoint of ethics and religion. The present study was conducted to investigate the frequency of fetal and maternal indications of legal abortion and also the maternal characteristics in Lorestan Province of Iran. Methods. As a descriptive cross-sectional study, all the cases with issued permits for legal abortion were selected by a census during 2017–2019. Descriptive data analysis was used to report the results. Event rates with Poisson 95% confidence intervals (CIs) were calculated based on the regional population. Results. A total of 305 cases were selected. The mean age of the mothers was 31.61 ± 7.48 years, and the mean of gestational age was 15.76 ± 2.80 weeks. Demographically, most cases were from Khorramabad city (101 cases) followed by Borujerd (51 cases) and Doroud (46 cases). The overall event rate was 1.732 per 10,000 individuals (95% CI: 1.543–1.938) of the general population of the region per 3 years. Fetal disturbance of the brain and spine was the most prevalent reason of abortion (24.92%, 95% CI: 19.63%–31.19%) followed by Down syndrome (19.34%, 95% CI: 14.73%–24.95), hydrops fetalis (12.79%, 95% CI: 9.09%–17.48%), and anencephaly (12.79%, 95% CI: 9.09%–17.48%). Conclusion. From each 10,000 individuals of the population, one to two cases of legal abortion were screened per 3 years. More than 90% of cases had fetal indication. In cities with lower event rates, we should plan for better screening.

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