Population dynamics of a migrant skipper butterflyParnara guttata (Lepidoptera: Hesperiidae) II. Survival rates of immature stages in paddy fields

Population dynamics and life history traits of the ‘giant’ limpet Scutellastra laticostata on intertidal limestone platforms at Rottnest Island, Western Australia, were recorded by interannual (January/February) monitoring of limpet density and size structure, and relocation of marked individuals, at 3 locations over periods of 13-16 yr between 1993 and 2020. Limpet densities ranged from 4 to 9 ind. m-2 on wave-swept seaward margins of platforms at 2 locations and on a rocky notch at the landward margin of the platform at a third. Juvenile recruits (25-55 mm shell length) were present each year, usually at low densities (<1 m-2), but localized pulses of recruitment occurred in some years. Annual survival rates of marked limpets varied among sites and cohorts, ranging from 0.42 yr-1 at the notch to 0.79 and 0.87 yr-1 on the platforms. A mass mortality of limpets on the platforms occurred in 2003, likely mediated by thermal stress during daytime low tides, coincident with high air temperatures and calm seas. Juveniles grew rapidly to adult size within 2 yr. Asymptotic size (L∞, von Bertalanffy growth model) ranged from 89 to 97 mm, and maximum size from 100 to 113 mm, on platforms. Growth rate and maximum size were lower on the notch. Our empirical observations and simulation models suggest that these populations are relatively stable on a decadal time scale. The frequency and magnitude of recruitment pulses and high rate of adult survival provide considerable inertia, enabling persistence of these populations in the face of sporadic climatic extremes.

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Population dynamics of rice leaffolders (Lepidoptera: Pyralidae) and their natural enemies in irrigated rice in the Philippines

Bulletin of Entomological Research ◽

10.1017/s0007485399000541 ◽

1999 ◽

Vol 89 (5) ◽

pp. 411-421 ◽

Cited By ~ 11

Author(s):

J. de Kraker ◽

A. van Huis ◽

K.L. Heong ◽

J.C. van Lenteren ◽

R. Rabbinge

Keyword(s):

Population Dynamics ◽

Natural Enemies ◽

Natural Enemy ◽

Survival Rates ◽

The Philippines ◽

Cnaphalocrocis Medinalis ◽

Irrigated Rice ◽

Larval Stages ◽

Ovipositional Preference ◽

Rice Leaffolders

AbstractPopulations of rice leaffolders and their natural enemies were studied in eight crops of irrigated rice in Laguna Province, the Philippines. The rice leaffolder complex consisted of three species: Cnaphalocrocis medinalis (Guenée), Marasmia patnalis Bradley and M. exigua Butler. Leaffolder population dynamics were characterized by an egg peak at maximum tillering and a broad larval peak around booting stage. Peak densities ranged from 0.2 to 2.0 larvae per hill. Most larvae originated from immigrant moths and there was no substantial second generation. The seasonal percentage egg parasitism by Trichogramma sp. ranged from 0 to 27%, and percentage larval parasitism from 14 to 56%. The braconid Macrocentrus philippinensis Ashmead was the most commonly reared larval parasitoid. Forty natural enemy taxa that may attack rice leaffolders were identified from suction and sweepnet samples: 24 predator taxa and 16 parasitoid taxa. The estimated survival rates from leaffolder egg to larval stages and between larval stages showed large variation between rice crops, but were not clearly correlated with observed levels of parasitism, natural enemy abundance, or natural enemy to leaffolder ratios. It is suggested that the generally low densities of rice leaffolders in Philippine transplanted rice are caused by their ovipositional preference for crops at the maximum tillering stage, allowing for only one generation, and by high immature mortality caused by the abundant and diverse complex of natural enemies.

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The Relationship of Spathimeigenia spinigera Townsend (Diptera: Tachinidae) to its Host, Neodiprion swainei Midd. (Hymenoptera: Diprionidae)

The Canadian Entomologist ◽

10.4039/ent94809-8 ◽

1962 ◽

Vol 94 (8) ◽

pp. 809-818 ◽

Cited By ~ 10

Author(s):

H. A. Tripp

Keyword(s):

Population Dynamics ◽

Pinus Banksiana ◽

Jack Pine ◽

Immature Stages ◽

Pine Sawfly ◽

Factors Influencing ◽

Form Part ◽

Extensive Program ◽

Relationship Of ◽

The Relationship

Studies on the parasites of the Swaine jack pine sawfly, Neodiprion swainei Midd., form part of an extensive program designed to assess the factors influencing population dynamics of this important defoliator of jack pine, Pinus banksiana Lamb. Investigations were carried out in the Province of Quebec between 1955 and 1959 near the headwaters of the Gatineau River, Abitibi County, and continued during 1960 and 1961 near the source of the Vermillion River, County Laviolette. In both areas, one of the principal parasites associated with N. swainei was the tachinid, Spathimeigenia spinigera Townsend. Descriptions of the immature stages of this parasite, and details of its behaviour were published previously (Tripp, 1960).

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Mortalities of the larvae of the Anopheles gambiae Giles complex and detection of predators by the precipitin test

Bulletin of Entomological Research ◽

10.1017/s0007485300003862 ◽

1973 ◽

Vol 62 (3) ◽

pp. 359-369 ◽

Cited By ~ 71

Author(s):

M. W. Service

Keyword(s):

Anopheles Gambiae ◽

High Mortality ◽

Survival Rates ◽

Age Distribution ◽

Fourth Instar ◽

Immature Stages ◽

Complex Species ◽

Precipitin Test ◽

Anopheles Gambiae Giles ◽

Time Specific

Larval populations of the Anopheles gambiae Giles complex (species A and B) were sampled in Kenya, and from the frequencies of the age distribution of the immature stages time-specific life-tables were constructed. Daily survival rates and instar mortalities showed that there was high mortality amongst fourth-instar larvae, due at least in part to infections of larval nematodes, Coelomomyces and epibionts. Antiserum to the A. gambiae complex was prepared in rabbits so that the precipitin test could be employed to detect the presence of A. gambiae in gut smears taken from possible predators. By this serological technique various spiders, Diptera, Coleoptera and amphibia were identified as predators. These may be very important in regulating populations of A. gambiae even in small collections of water.

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Population dynamics of hispid cotton rats (Sigmodon hispidus) across a nitrogen-amended landscape

Canadian Journal of Zoology ◽

10.1139/z03-084 ◽

2003 ◽

Vol 81 (6) ◽

pp. 994-1003 ◽

Cited By ~ 7

Author(s):

Jay E Clark ◽

Eric C Hellgren ◽

Eric E Jorgensen ◽

Susan J Tunnell ◽

David M Engle ◽

...

Keyword(s):

Population Dynamics ◽

Reproductive Success ◽

Survival Rates ◽

Canopy Cover ◽

Sigmodon Hispidus ◽

Old Field ◽

Higher Plant ◽

Population Growth Rates ◽

Low Level ◽

Cotton Rats

We conducted a markrecapture experiment to examine the population dynamics of hispid cotton rats (Sigmodon hispidus) in response to low-level nitrogen amendments (16.4 kg nitrogen/ha per year) and exclosure fencing in an old-field grassland. The experimental design consisted of sixteen 0.16-ha plots with 4 replicates of each treatment combination. We predicted that densities, reproductive success, movement probabilities, and survival rates of cotton rats would be greater on nitrogen-amended plots because of greater aboveground biomass and canopy cover. Population densities of cotton rats tended to be highest on fenced nitrogen plots, but densities on unfenced nitrogen plots were similar to those on control and fenced plots. We observed no distinct patterns in survival rates, reproductive success, or movement probabilities with regard to nitrogen treatments. However, survival rates and reproductive success tended to be higher for cotton rats on fenced plots than for those on unfenced plots and this was likely attributable to decreased predation on fenced plots. As low-level nitrogen amendments continue to be applied, we predict that survival, reproduction, and population-growth rates of cotton rats on control plots, especially fenced plots with no nitrogen amendment, will eventually exceed those on nitrogen-amended plots as a result of higher plant-species diversity, greater food availability, and better quality cover.

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SPATIOTEMPORAL VARIATION IN SURVIVAL RATES: IMPLICATIONS FOR POPULATION DYNAMICS OF YELLOW-BELLIED MARMOTS

Ecology ◽

10.1890/0012-9658(2006)87[1027:svisri]2.0.co;2 ◽

2006 ◽

Vol 87 (4) ◽

pp. 1027-1037 ◽

Cited By ~ 36

Author(s):

Arpat Ozgul ◽

Kenneth B. Armitage ◽

Daniel T. Blumstein ◽

Madan K. Oli

Keyword(s):

Population Dynamics ◽

Survival Rates ◽

Spatiotemporal Variation

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DESIGN OF A SAMPLING PLAN FOR STUDIES ON THE POPULATION DYNAMICS OF THE CABBAGE MAGGOT, HYLEMYA BRASSICAE (DIPTERA: ANTHOMYIIDAE)

The Canadian Entomologist ◽

10.4039/ent1021513-12 ◽

1970 ◽

Vol 102 (12) ◽

pp. 1513-1518 ◽

Cited By ~ 13

Author(s):

M. K. Mukerji ◽

D. G. Harcourt

Keyword(s):

Population Dynamics ◽

Population Density ◽

Plant Root ◽

Immature Stages ◽

Southwestern Part ◽

Sample Unit ◽

Diameter Core ◽

Sampling Variation ◽

Hylemya Brassicae ◽

Cabbage Maggot

AbstractA study of sampling variation in field populations of the cabbage maggot, Hylemya brassicae (Bouché), on cabbage in Ontario, revealed that inter-plant and block differences were rarely significant. For the immature stages, the most appropriate sample unit was the plant root together with a 4- to 6-in. diameter core of soil. The number of samples required was inversely proportional to population density; this relationship was graphed for three levels of sampling precision.The insect is bivoltine in eastern Ontario but has three generations in the southwestern part of the province.

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What do we know about survival of Common cranes? An elementary introduction with Euring databank

10.1101/2021.09.02.458691 ◽

2021 ◽

Author(s):

Luis M. Bautista ◽

Juan C. Alonso

Keyword(s):

Population Dynamics ◽

Western Europe ◽

Great Increase ◽

Survival Rates ◽

Apparent Survival ◽

Elapsed Time ◽

In Captivity ◽

Species Population ◽

Grus Grus ◽

Common Crane

The increase of the western populations of Common cranes (Grus grus) in the last five decades highlights the need to estimate survival rates. According to Euring databank (EDB), the oldest Common crane ever known was 27 years old in year 2017. This lifespan was obtained by means of 24,900 recoveries of 2,124 ringed cranes collected between years 1936 and 2017. Nearly all cranes were ringed and observed in the last 30 years, and therefore the elapsed time was not enough to reach the maximum longevity reported for the species in captivity (43 years, Mitchell 1911). Life expectancy was five years on average after the ring was attached. Here we provide some elementary analyses to calculate the annual apparent survival rate (ϕ = 0.85) and the annual encounter probability (p = 0.45) of Common cranes, as a first step to advance in the knowledge of the species' population dynamics. The great increase of breeding and wintering crane populations in western Europe in the last decades remains largely unexplained.

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Population dynamics of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou) in British Columbia, Canada

10.26686/wgtn.12971858.v1 ◽

2020 ◽

Author(s):

Heiko Wittmer ◽

BN McLellan ◽

DR Seip ◽

JA Young ◽

TA Kinley ◽

...

Keyword(s):

British Columbia ◽

Population Dynamics ◽

Rangifer Tarandus ◽

Population Decline ◽

Survival Rates ◽

Adult Survival ◽

Rangifer Tarandus Caribou ◽

Vital Rates ◽

Woodland Caribou ◽

Annual Survival

We used census results and radiotelemetry locations of >380 collared individuals sampled over the entire distribution of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) in British Columbia, Canada, to delineate population structure and document the size and trend of the identified populations. We also describe the spatial pattern of decline and the causes and timing of adult mortality and provide estimates of vital rates necessary to develop a population viability analysis. Our results indicate that the abundance of mountain caribou in British Columbia is declining. We found adult female annual survival rates below annual survival rates commonly reported for large ungulates. The major proximate cause of population decline appears to be predation on adult caribou. Spatial patterns of population dynamics revealed a continuous range contraction and an increasing fragmentation of mountain caribou into smaller, isolated subpopulations. The population fragmentation process predominantly occurs at the outer boundaries of the current distribution. Our results indicate that recovery strategies for mountain caribou should be directed at factors contributing to the fragmentation and isolation of mountain caribou populations as well as management strategies aimed at increasing adult survival. © 2005 NRC Canada.

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Factors regulating kit fox populations

Canadian Journal of Zoology ◽

10.1139/z97-830 ◽

1997 ◽

Vol 75 (12) ◽

pp. 1982-1988 ◽

Cited By ~ 35

Author(s):

P. J. White ◽

Robert A. Garrott

Keyword(s):

Population Dynamics ◽

Interference Competition ◽

Survival Rates ◽

Prey Abundance ◽

Short Term ◽

Density Dependent ◽

Kit Fox ◽

Vulpes Macrotis ◽

Predominant Factor ◽

Major Factors

Recent declines in several populations of kit foxes (Vulpes macrotis) have been attributed to decreased prey abundance and increased coyote-related mortalities. However, it is not known if short-term fluctuations in prey abundance or interference competition by coyotes can regulate the population dynamics of kit foxes. We coalesced data from all pertinent studies of kit and swift foxes and examined their numerical responses to changes in prey abundance. We also explored the influence of coyote-related mortalities on fox population dynamics. Fox density was positively correlated with leporid abundance, and fox reproduction rates were density-dependent at low prey densities. The proportion of the fox population killed by coyotes increased linearly over low to moderate fox densities, and survival rates of adult foxes decreased as the proportion of mortalities caused by coyotes increased. Hence, prey abundance and interference competition by coyotes may regulate fox populations. We suspect that prey abundance, and behavioral spacing mechanisms, are the major factors regulating fox densities. Coyote-related mortalities may be a less predominant factor, but could still act in concert with prey abundance to reduce the amplitude of fox population dynamics and keep foxes at lower densities than they might otherwise attain.

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