scholarly journals Survival and Natal Dispersal of Juvenile Snowy Plovers (Charadrius Alexandrinus) in Central Coastal California

The Auk ◽  
2007 ◽  
Vol 124 (3) ◽  
pp. 1023-1036 ◽  
Author(s):  
Lynne E. Stenzel ◽  
Gary W. Page ◽  
Jane C. Warriner ◽  
John S. Warriner ◽  
Douglas E. George ◽  
...  
Keyword(s):  
Large Body ◽  
Weather Conditions ◽  
Natal Dispersal ◽  
Adult Survival ◽  
Juvenile Survival ◽  
Coast Range ◽  
Breeding Sites ◽  
Charadrius Alexandrinus ◽  
Snowy Plover ◽  
Snowy Plovers

AbstractJuvenile survival and dispersal rates are important demographic parameters in predicting the viability of avian populations, but estimates are seldom available because mortality is usually confounded with permanent natal dispersal in analyses of live-encounter data. We used the Barker model for combined captures, recoveries, and resightings to estimate juvenile survival in fledgling Snowy Plover (Charadrius alexandrinus) for the 6.5-to-10.5-month period between fledging at 28 days and 1 April the following year, on the central California coast, for a 16-year period, 1984-1999. By using a large body of year-round sighting data from throughout the species' Pacific-coast range, we estimated true survival and quantified natal dispersal rates and distances. Juvenile survival estimates varied annually between 0.283 ± 0.028 (mean ± SE) and 0.575 ± 0.061 with no trend over the study, and paralleled higher adult survival in our most parsimonious models. In comparison, annual survival of banded chicks from hatching to fledging at age 28 days was 0.285–0.483 (x̄ = 0.382 ± 0.014 SE) for those 16 years. Males were more likely to disperse from Monterey Bay for winter and females were more likely to disperse for breeding. Dispersal distances to breeding sites were usually within 10 km of natal sites (64%) and seldom >50 km (16%). The present study provides the first estimate of true survival for a juvenile shorebird and new information on survival and dispersal rates that will be useful for modeling Snowy Plover population viability. Studies of local winter residents, focused on predator pressure and weather conditions, could further advance our understanding of factors determining Snowy Plover survival.Supervivencia y Dispersión Natal de Juveniles de Charadrius alexandrinus en la Costa Central de California

SURVIVAL AND NATAL DISPERSAL OF JUVENILE SNOWY PLOVERS (CHARADRIUS ALEXANDRINUS) IN CENTRAL COASTAL CALIFORNIA

The Auk ◽  
2007 ◽  
Vol 124 (3) ◽  
pp. 1023 ◽  
Author(s):  
Lynne E. Stenzel ◽  
Gary W. Page ◽  
Jane C. Warriner ◽  
John S. Warriner ◽  
Douglas E. George ◽  
...  
Keyword(s):  
Natal Dispersal ◽  
Charadrius Alexandrinus ◽  
Snowy Plovers

Spacing out at Mono Lake: Breeding Success, Nest Density, and Predation in the Snowy Plover

The Auk ◽  
1983 ◽  
Vol 100 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Gary W. Page ◽  
Lynne E. Stenzel ◽  
David W. Winkler ◽  
Christopher W. Swarth
Keyword(s):  
Nesting Success ◽  
Mono Lake ◽  
Limiting Factor ◽  
Nest Density ◽  
Population Stability ◽  
Female Population ◽  
Charadrius Alexandrinus ◽  
Snowy Plover ◽  
Series Of Experiments ◽  
Snowy Plovers

Abstract Snowy Plovers (Charadrius alexandrinus) nesting on the exposed lake bed surrounding Mono Lake, California lose up to 40% of their clutches. Most are destroyed by predators, predominantly California Gulls (Larus californicus). In 1978 Snowy Plover reproduction was estimated at 0.49-0.70 fledged young per female. Population stability was estimated to require 0.80 fledged young per female. A series of experiments with artificial clutches placed at different densities in the nesting area demonstrates that the predators can have an effect on the plovers' nesting success that is dependent upon their nest density. The maintenance of low nesting density is an important antipredator adaptation. We consider predation on clutches and broods to be the major limiting factor on the Snowy Plover population at Mono Lake.

Evaluation of parental raspberry breeding forms for fruit size

2021 ◽  
pp. 16-22
Author(s):  
M. A. Podgaetskiy ◽  
S. N. Evdokimenko
Keyword(s):  
Objective Assessment ◽  
Fruit Size ◽  
Weather Conditions ◽  
Base Station ◽  
Average Weight ◽  
Trial Period ◽  
Parental Form ◽  
Breeding Sites ◽  
Berry Weight ◽  
Berry Size

Te article tackles the feasibility of improving the raspberry fruit size as an important production and marketability factor. Te trials included 22 domestic and foreign cultivars, 11 selected forms of raspberry, as well as ten cross-breeding combinations and three open-pollinated forms. Te assessment of parental forms and hybrids was carried out at the collection and breeding sites of the Kokino base station of Federal Horticultural Center for Breeding, Agrotechnology and Nursery during 2016-2020. Fruits were harvested from regular cultivar bushes every 2 days in triplicate. Te average weight was determined per 100 berries in each replicate. Cultivars and hybrids were divided into three groups, small- (3.6 g). Te average berry weight in hybrid nurslings was estimated per plant. Each plant was sampled with 30 berries. Weighing was performed with an SCC-750 electronic scales device. Te weather conditions of the trial period were contrast, allowing a more objective assessment of the collection and breeding raspberry material by berry weight. Te following cultivars were identified as the sources of improved berry size in the parental form trials: Maria, Cascade Delight, Fenomen, Lavina, Cowichan, Patricia, Laczka, Glen Ample and selections 2-115-1, 8-13-2, 18-11-3, 18-11-2, 2-90-2 and 2-90-3. Tese forms had an average trial-period berry weight of 3.7-4.3 g least affected by weather conditions. Te inspection of hybrids revealed the best parental forms for obtaining new raspberry cultivars with an improved berry weight: Maria, Fenomen, Lavina, Cowichan, Glen Ample and the selected form 8-13-2. Te promising cross-combinations are: 2-12-1 x Fenomen, Lavina x Ulybka, 8-13-2 x Peresvet, as well as the open-pollinated offspring of Glen Ample, Cowichan and Maria. Large-fruited genotypes isolated in these lineages will be used in further breeding to increase the fruit size in raspberry.

scholarly journals Juvenile and Adult Survival of Swainson's Thrush (Catharus Ustulatus) in Coastal California: Annual Estimates Using Capture-Recapture Analyses

The Auk ◽  
2003 ◽  
Vol 120 (4) ◽  
pp. 1188-1194
Author(s):  
Thomas Gardali ◽  
Daniel C. Barton ◽  
Jennifer D. White ◽  
Geoffrey R. Geupel
Keyword(s):  
Adult Survival ◽  
Juvenile Survival ◽  
Survival Ratio ◽  
Catharus Ustulatus ◽  
Survival Estimate ◽  
Neotropical Migrant ◽  
Probability Estimates ◽  
Capture Recapture ◽  
Source Sink ◽  
Range Of Values

Abstract We estimated annual rates of survival for juvenile and adult Swainson's Thrushes (Catharus ustulatus) using capture-recapture analyses from 22 years of mist-neting data in coastal California (n= 2,651 individual captures). Our apparent survival estimate was 56% for adults and 25% for juveniles. We are the first to estimate an annual juvenile survival rate for a Neotropical migrant using capture-recapture probability estimates. Like most estimates of annual survival, we could not distinguish between dispersal away from our study area (which is likely high for juveniles) and mortality. Hence, survival is underestimated. However, our juvenile survival estimate did not include the period from fledging to independence, a time when mortality can be high. Many researchers have assumed juvenile survival to be half that of adult survival in population models (e.g. source-sink). Our juvenile to adult survival ratio was 45% (95% CI = 27 to 65%). We caution researchers from simply assuming that juvenile survival approximates half of adult survival when modeling populations and suggest using a range of values. Using a range of values is prudent because of the potential for annual variation, site-specific variation, and especially because estimates are imprecise or completely lacking.

scholarly journals Range expansion is associated with increased survival and fecundity in a long-lived bat species

2019 ◽  
Vol 286 (1906) ◽  
pp. 20190384 ◽  
Author(s):  
P.-L. Jan ◽  
L. Lehnen ◽  
A.-L. Besnard ◽  
G. Kerth ◽  
M. Biedermann ◽  
...  
Keyword(s):  
Life History ◽  
Population Growth ◽  
Range Expansion ◽  
Empirical Studies ◽  
Simulated Data ◽  
Adult Survival ◽  
Juvenile Survival ◽  
Average Growth ◽  
Population Growth Rates ◽  
Expanding Population

The speed and dynamics of range expansions shape species distributions and community composition. Despite the critical impact of population growth rates for range expansion, they are neglected in existing empirical studies, which focus on the investigation of selected life-history traits. Here, we present an approach based on non-invasive genetic capture–mark–recapture data for the estimation of adult survival, fecundity and juvenile survival, which determine population growth. We demonstrate the reliability of our method with simulated data, and use it to investigate life-history changes associated with range expansion in 35 colonies of the bat species Rhinolophus hipposideros . Comparing the demographic parameters inferred for 19 of those colonies which belong to an expanding population with those inferred for the remaining 16 colonies from a non-expanding population reveals that range expansion is associated with higher net reproduction. Juvenile survival was the main driver of the observed reproduction increase in this long-lived bat species with low per capita annual reproductive output. The higher average growth rate in the expanding population was not associated with a trade-off between increased reproduction and survival, suggesting that the observed increase in reproduction stems from a higher resource acquisition in the expanding population. Environmental conditions in the novel habitat hence seem to have an important influence on range expansion dynamics, and warrant further investigation for the management of range expansion in both native and invasive species.

scholarly journals Determining Effects of Winter Weather Conditions on Adult Amblyomma americanum (Acari: Ixodidae) Survival in Connecticut and Maine, USA

Insects ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Megan Linske ◽  
Scott Williams ◽  
Kirby Stafford ◽  
Charles Lubelczyk ◽  
Elizabeth Henderson ◽  
...  
Keyword(s):  
Leaf Litter ◽  
Range Expansion ◽  
Weather Conditions ◽  
The United States ◽  
Amblyomma Americanum ◽  
Snow Accumulation ◽  
Adult Survival ◽  
Winter Weather ◽  
Hourly Temperature ◽  
Significant Difference

The lone star tick (Amblyomma americanum L.) is native to the United States, with its primary range encompassing the Southeast and portions of the Midwest. It is an aggressive ectoparasite that actively seeks out hosts through detection of carbon dioxide and vibrations and can transfer ehrlichiosis-causing bacteria as well as a carbohydrate that causes alpha-gal syndrome (red meat allergy) in humans. It has become of increasing concern as its range has recently expanded into coastal regions of the Northeast. Historically, harsh northeastern winter weather conditions made these areas inhospitable for A. americanum survival, but a warming climate coupled with increased host availability seem to have facilitated their range expansion. We developed a study to observe the effects of weather conditions on adult A. americanum overwintering survival. The study was conducted over three years in Connecticut and Maine. Ground-level conditions were manipulated to determine the effects of differing combinations of natural insulative barriers (leaf litter and snow accumulation) on adult A. americanum survival. We determined that there was a significant difference in survival between the two states, between years in Maine, and between sexes within Connecticut. However, presence or absence of snow and/or leaf litter had no impact on survival. Overall, we found a positive correlation between mean hourly temperature and adult survival in Maine, where temperatures were consistently below freezing. The results of this study can be included in an adaptive, predictive analytic model to accommodate the expected fluctuations and range expansion of A. americanum that will most likely accompany an increase in temperatures throughout the Northeast.

Natal and Breeding Dispersal in House Wrens (Troglodytes aedon)

The Auk ◽  
1988 ◽  
Vol 105 (3) ◽  
pp. 480-491 ◽  
Author(s):  
Nancy E. Drilling ◽  
Charles F. Thompson
Keyword(s):  
Reproductive Success ◽  
Natal Dispersal ◽  
Breeding Dispersal ◽  
Adult Males ◽  
Troglodytes Aedon ◽  
Grid Pattern ◽  
Breeding Sites ◽  
House Wrens ◽  
Previous Season ◽  
Central Illinois

Abstract We studied the natal and breeding dispersal of yearling and adult House Wrens (Troglodytes aedon) for 7 yr in central Illinois. The forested study areas contained 910 identical nest boxes placed in a grid pattern. On average 38.1% (n = 643) of the adult males and 23.3% (n = 1,468) of the adult females present in one year returned the next; 2.8% (n = 6,299) of the nestlings that survived to leave the nest returned each year. Adult male (median distance = 67 m) and adult female (median = 134 m) breeding dispersal was less than yearling male (median = 607.5 m) and yearling female (median = 674 m) natal dispersal. Females that returned had produced more offspring the previous season than had nonreturning females, and females that successfully produced at least one chick in their last nesting attempt of the previous season moved shorter distances than did unsuccessful females. There were, however, no consistent differences between returning and nonreturning females in two other measures of reproductive success. Females that were unsuccessful in their last breeding attempt of the previous year were more likely to be successful in their next attempt if they moved two or more territories than if they did not move. Reproductive success did not affect the likelihood that a male would return nor the distance that he moved. The success of subsequent nesting attempts by males was also not related to the distance moved. Inbreeding avoidance may explain differences between breeding and natal dispersal, but it does not explain the lack of difference in dispersal of yearling females and males. Differences between adult and yearling dispersal are best explained by advantages accruing to adults that remain near former breeding sites and by the necessity for yearlings to move farther because of their late return from the wintering grounds. The advantages for adults to reoccupy previous breeding sites are counterbalanced, especially in females, by advantages associated with moving after breeding failure.

Characterization of elasticity patterns of North American freshwater fishes

2006 ◽  
Vol 63 (9) ◽  
pp. 2050-2066 ◽  
Author(s):  
Luis A Vélez-Espino ◽  
Michael G Fox ◽  
Robert L McLaughlin
Keyword(s):  
Population Growth ◽  
North American ◽  
Growth Rates ◽  
Freshwater Fishes ◽  
Adult Survival ◽  
Juvenile Survival ◽  
Vital Rates ◽  
Population Growth Rates ◽  
North American Freshwater ◽  
Trade Offs

We applied elasticity analysis to 88 North American freshwater fishes to assess the relative impacts of changes in the vital rates on asymptotic population growth. Variance in vital rates was summarized for four distinct functional groups: (i) species with population growth rates strongly sensitive to perturbations in adult survival; (ii) species with population growth rates sensitive to perturbations in overall survival; (iii) species with population growth rates most sensitive to perturbations in juvenile survival; and (iv) species with population growth rates sensitive to perturbations in juvenile survival and fecundity. The results of the present study also showed that (a) elasticity patterns cannot be inferred in a straightforward manner from trade-offs between life-history traits, (b) the sensitivity of a population's growth rate to changes in adult survival and fecundity can be predicted empirically from life span and age at maturity, respectively, (c) elasticities are highly conserved among genera within the same taxonomic family, and (d) there are key divergences between elasticity patterns of freshwater fish and other vertebrate taxa.

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