scholarly journals Philopatry, Site Tenacity, Mate Fidelity, and Adult Survival in Sabine's Gulls

The Condor ◽  
2005 ◽  
Vol 107 (2) ◽  
pp. 416-423
Author(s):  
Iain J. Stenhouse ◽  
Gregory J. Robertson
Keyword(s):  
Life History ◽  
Survival Rates ◽  
Life History Strategies ◽  
Adult Survival ◽  
Vital Rates ◽  
Breeding Area ◽  
Xema Sabini ◽  
East Bay ◽  
Sabine’S Gull ◽  
Historia De Vida

AbstractQuantifying the dynamics of populations is fundamental to understanding life-history strategies, and essential for population modeling and conservation biology. Few details of the demography and life history of the Sabine's Gull (Xema sabini) are known. Uniquely color banded Sabine's Gulls breeding in East Bay, Southampton Island, Nunavut, in the eastern Canadian Arctic, were examined from 1998–2002 to quantify vital rates. Generally, birds banded as chicks first returned to the breeding area in their third year, and the earliest case of first breeding was confirmed at three years of age. Sabine's Gull pairs showed strong tenacity to their breeding site from year to year, with most pairs nesting within approximately 100 m of the previous year's site, regardless of nest success. Individuals also showed strong year-to-year fidelity to their mates. However, birds whose previous partner failed to return, or returned late, were quick to remate. On rare occasions, birds were not seen in the study area in a particular year, but seen again in later years, either because they were missed, had dispersed temporarily outside the study area, or did not return to the breeding area in some years. Standard Capture-Mark-Recapture analyses were used to calculate local resighting and survival rates. Local annual survival rate of adult Sabine's Gulls was 0.89 ± 0.03, similar to annual adult survival estimates recently reported for other small to medium-sized gulls and terns.Filopatría, Apego al Sitio de Nidificación, Fidelidad a la Pareja y Supervivencia de los Adultos en Xema sabiniResumen. Cuantificar la dinámica de las poblaciones es fundamental para entender las estrategias de historia de vida y es esencial para la realización de modelos poblacionales y para la conservación biológica. Se conocen pocos detalles sobre la demografía e historia de vida de la gaviota Xema sabini. Para cuantificar sus tasas vitales, en este estudio se examinaron gaviotas anilladas que estaban criando en East Bay, Southampton Island, Nunavut (ártico canadiense) entre 1998 y 2002. Generalmente, las aves que fueron anilladas como pichones regresaron al área de cría en su tercer año, y el caso de primer apareamiento más temprano fue confirmado a los tres años de edad. Las parejas exhibieron un fuerte apego a su sitio de nidificación de año a año: la mayoría nidificaron a menos de aproximadamente 100 m del lugar en donde lo hicieron el año anterior, independientemente de su éxito de nidificación. Los individuos también mostraron gran fidelidad a sus parejas año a año. Sin embargo, las aves cuyas parejas no regresaron o lo hicieron tardíamente, encontraron nuevas parejas rápidamente. En raras ocasiones, algunas aves no fueron vistas en el área de estudio durante un año particular, pero fueron vistas en años siguientes, ya sea porque no fueron detectadas a pesar de estar presentes, porque se habían dispersado hacia afuera del área de estudio temporalmente o porque no regresaron al área de cría en algunos años. Se emplearon análisis estándar de captura, marcado y recaptura para calcular las tasas locales de reavistamiento y supervivencia. La tasa de supervivencia anual de los adultos de X. sabini fue 0.89 ± 0.03, un valor similar a los valores estimados de supervivencia anual de adultos documentados recientemente para gaviotines y otras gaviotas de tamaño medio.

scholarly journals Corticosterone, testosterone and life-history strategies of birds

2010 ◽  
Vol 277 (1697) ◽  
pp. 3203-3212 ◽  
Author(s):  
Michaela Hau ◽  
Robert E. Ricklefs ◽  
Martin Wikelski ◽  
Kelly A. Lee ◽  
Jeffrey D. Brawn
Keyword(s):  
Life History ◽  
Body Mass ◽  
Breeding Season ◽  
Life History Traits ◽  
Survival Rates ◽  
Life History Strategies ◽  
Adult Survival ◽  
Tropical Species ◽  
Published Data ◽  
Season Length

Steroid hormones have similar functions across vertebrates, but circulating concentrations can vary dramatically among species. We examined the hypothesis that variation in titres of corticosterone (Cort) and testosterone (T) is related to life-history traits of avian species. We predicted that Cort would reach higher levels under stress in species with higher annual adult survival rates since Cort is thought to promote physiological and behavioural responses that reduce risk to the individual. Conversely, we predicted that peak T during the breeding season would be higher in short-lived species with high mating effort as this hormone is known to promote male fecundity traits. We quantified circulating hormone concentrations and key life-history traits (annual adult survival rate, breeding season length, body mass) in males of free-living bird species during the breeding season at a temperate site (northern USA) and a tropical site (central Panama). We analysed our original data by themselves, and also combined with published data on passerine birds to enhance sample size. In both approaches, variation in baseline Cort (Cort0) among species was inversely related to breeding season length and body mass. Stress-induced corticosterone (MaxCort) also varied inversely with body mass and, as predicted, also varied positively with annual adult survival rates. Furthermore, species from drier and colder environments exhibited lower MaxCort than mesic and tropical species; T was lowest in species from tropical environments. These findings suggest that Cort0, MaxCort and T modulate key vertebrate life-history responses to the environment, with Cort0 supporting energetically demanding processes, MaxCort promoting survival and T being related to mating success.

Migration distance is a fundamental axis of the slow-fast continuum of life history in boreal birds

The Auk ◽  
2021 ◽  
Author(s):  
Benjamin M Winger ◽  
Teresa M Pegan
Keyword(s):  
Life History ◽  
Survival Rates ◽  
Reproductive Investment ◽  
Seasonal Migration ◽  
Adult Survival ◽  
Vital Rates ◽  
Long Distance ◽  
Migration Distance ◽  
Breeding Grounds ◽  
Survival And Reproduction

Abstract Seasonal migration is intrinsically connected to the balance of survival and reproduction, but whether migratory behavior influences species’ position on the slow-fast continuum of life history is poorly understood. We found that boreal-breeding birds that migrate long distances exhibit higher annual adult survival and lower annual reproductive investment relative to co-distributed boreal species that migrate shorter distances to winter closer to their breeding grounds. Our study uses “vital rates” data on reproductive output and survivorship compiled from the literature for a species assemblage of 45 species of mostly passerine birds. These species breed sympatrically in North American boreal forests but migrate to a diversity of environments for the northern winter. After controlling for body size and phylogeny, migration distance and apparent annual adult survival are positively related across species. Both migration distance and survival are positively correlated with wintering in environments that are warmer, wetter, and greener. At the same time, longer migrations are associated with reduced time spent on the breeding grounds, lower clutch sizes, and lower fecundity (clutch size × maximum number of broods per year). Although seasonal migration is often associated with high mortality, our results suggest that long-distance migration imposes selection pressures that both confer and demand high adult survival rates. That is, owing to the reproductive cost of long-distance migration, this strategy can only persist if balanced by high adult survival. Our study supports the idea that migration evolves to promote survival of species breeding in seasonal environments. In boreal birds, the evolution of the longest migrations yields the highest survival, but at an inherent cost to annual fecundity. Our results therefore reveal migratory distance as a fundamental axis of the slow-fast continuum that predicts, and is inextricable from, the balance of survival and reproduction.

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

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.

scholarly journals Variation in Demography and Life-History Strategies Across the Range of a Declining Mountain Bird Species

2021 ◽  
Vol 9 ◽  
Author(s):  
Arnaud G. Barras ◽  
Sébastien Blache ◽  
Michael Schaub ◽  
Raphaël Arlettaz
Keyword(s):  
Life History ◽  
Environmental Change ◽  
Life History Traits ◽  
Local Population ◽  
Bird Species ◽  
Life History Strategies ◽  
Adult Survival ◽  
Northwestern Part ◽  
European Alps ◽  
Demographic Processes

Species- and population-specific responses to their environment may depend to a large extent on the spatial variation in life-history traits and in demographic processes of local population dynamics. Yet, those parameters and their variability remain largely unknown for many cold-adapted species, which are exposed to particularly rapid rates of environmental change. Here, we compared the demographic traits and dynamics for an emblematic bird species of European mountain ecosystems, the ring ouzel (Turdus torquatus). Using integrated population models fitted in a Bayesian framework, we estimated the survival probability, productivity and immigration of two populations from the Western European Alps, in France (over 11 years) and Switzerland (over 6 years). Juvenile apparent survival was lower and immigration rate higher in the Swiss compared to the French population, with the temporal variation in population growth rate driven by different demographic processes. Yet, when compared to populations in the northwestern part of the range, in Scotland, these two Alpine populations both showed a much lower productivity and higher adult survival, indicating a slower life-history strategy. Our results suggest that demographic characteristics can substantially vary across the discontinuous range of this passerine species, essentially due to contrasted, possibly locally evolved life-history strategies. This study therefore raises the question of whether flexibility in life-history traits is widespread among boreo-alpine species and if it might provide adaptive potential for coping with current environmental change.

scholarly journals Human pressures filter out the less resilient demographic strategies in natural populations of plants and animals worldwide

2021 ◽  
Author(s):  
Thomas Merrien ◽  
Katrina Joan Davis ◽  
Pol Capdevila ◽  
Moreno Di Marco ◽  
Roberto Salguero-Gomez
Keyword(s):  
Life History ◽  
Human Activities ◽  
Land Surface ◽  
Urban Areas ◽  
Life History Traits ◽  
Natural Populations ◽  
Life History Strategies ◽  
Vital Rates ◽  
Long Distance ◽  
Animal Populations

The exponential growth that has characterised human societies since the industrial revolution has fundamentally modified our surroundings. Examples include rapid increases in agricultural fields, now accounting for 37% of the land surface, as well as increases in urban areas, projected to triple worldwide by 2030. As such, understanding how species have adapted to and will respond to increasing human pressures is of key importance. Resilience, the ability of an ecological system to resist, recover, and even benefit from disturbances, is a key concept in this regard. Here, using a recently develop comparative demographic framework, we examine how the inherent ability of 921 natural populations of 279 plants and 45 animal species worldwide to respond to disturbances correlates with human settlement size and human activities. We develop a spatially and phylogenetically explicit model parameterised with life history traits and metrics of demographic resilience using the open-access COMPADRE and COMADRE databases, coupled with high-resolution human impact information via the Human Footprint database. We expected: (H1) populations located nearer urban areas to have a greater ability to resist, recover, or benefit from human-related disturbances compared to pristine habitats; (H2) human effects on the responses of animal populations to disturbances to depend on the ability for long-distance mobility; and (H3): human pressures to constrain the repertoire of life history strategies of animal and plant species via their effects on underlying vital rates and life history traits. We find that: (1) urban areas host a limited diversity of strategies that achieve demographic resilience with, on average, more resistant and faster-recovery populations located near human activities than in pristine habitats; (2) species with limited mobility tend to be more strongly affected by human activities than those with long-distance mobility; and (3) human pressures correlate with a limited set of vital rates and life history traits, including the ability to shrink, and reproduce earlier. Our results provide a tangible picture of how, having drastically transformed terrestrial landscapes, humans have shaped the ways animals and plants respond to disturbances.

Demographic responses of Virginia opossums to limitation at their northern boundary

2004 ◽  
Vol 82 (7) ◽  
pp. 1126-1134 ◽  
Author(s):  
L Leann Kanda ◽  
Todd K Fuller
Keyword(s):  
Life History ◽  
Survival Rate ◽  
Demographic Data ◽  
Survival Rates ◽  
Life History Strategy ◽  
Didelphis Virginiana ◽  
Winter Survival ◽  
Life History Strategies ◽  
Physiological Limit ◽  
Virginia Opossum

The precise response of a population at its distributional edge to the limiting extrinsic factor should be mediated by the demography of the species. We applied this principle to understanding the northern distributional potential of the Virginia opossum (Didelphis virginiana Kerr, 1792). We reviewed the literature for demographic data that we then used to build model populations. Juvenile over-winter survival was adjusted to determine the survival necessary for a stable population. To put the results in the context of life-history strategy and ecological niche, we built models for two other medium-sized mammals with similar distributions, the raccoon (Procyon lotor (L., 1758)) and the muskrat (Ondatra zibethicus (L., 1766)). Northern raccoon populations may sustain juvenile winter survival rates of <0.50 because adult females live to reproduce in multiple years. Muskrat juveniles may need a winter survival rate of only 0.40 in average years because reproduction is very high. In contrast, young northern opossums need a survival rate of 0.81 over winter to compensate for low prewinter survival. Raccoons and muskrats, through different life-history strategies, should be able to expand their northern distribution to the winter-induced physiological limit. However, opossum populations should fail before the average individual physiological limit is reached.

Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals

1999 ◽  
Keyword(s):  
Life History ◽  
Population Growth ◽  
Growth Rates ◽  
Anthropogenic Impacts ◽  
Survival Rates ◽  
Conservation Strategies ◽  
Adult Survival ◽  
Population Growth Rates ◽  
Important Prey ◽  
The Status

<em>Abstract.</em> —Seabirds become mature at a late age, experience low annual fecundity, often refrain from breeding, and enjoy annual adult survival rates as high as 98%. This suite of life history characteristics limits the capacity for seabird populations to recover quickly from major perturbations, and presents important conservation challenges. Concern over anthropogenic impacts on seabird populations has led to the initiation of long-term field programs to monitor seabird reproductive performance and population dynamics. In addition, seabirds have been recognized as potentially useful and economical indicators of the state of the marine environment and, in particular, the status of commercially important prey stocks. This paper reviews demographic and life history attributes of seabird populations and uses this information to explore the consequences of longevity from the respective standpoints of conservation and monitoring goals. Analysis of a simplified life cycle model reveals that maximum potential population growth rates (λ) under ideal circumstances fall within the range of 1.03–1.12 for most species, though growth rates realized in nature will always be lower. Elasticity analysis confirms that seabird population growth rates are extremely sensitive to small variations in adult survival rates, and dictates that survival monitoring should be considered an essential component of conservation strategies. As in other organisms with long life spans, ecological and physiological costs of reproduction are expected to figure prominently in seabird reproductive decisions. Consequently, understanding how seabirds allocate reproductive effort in response to varying environmental conditions is an important prerequisite for correctly interpreting field data from monitoring studies.

Life-history reference points for management of an exploited tropical seahorse

2013 ◽  
Vol 64 (3) ◽  
pp. 185 ◽  
Author(s):  
Siân K. Morgan ◽  
Amanda C. J. Vincent
Keyword(s):  
Life History ◽  
Survival Rates ◽  
Reef Fishes ◽  
Reproductive Activity ◽  
Reference Points ◽  
Management Approach ◽  
Growth Equation ◽  
Vital Rates ◽  
Underwater Visual Census ◽  
Population Turnover

The present research provides the first demographic reference points for tropical seahorses, relevant to conservation of this largely tropical genus Hippocampus, which is listed on the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II. Findings defined the life-history and in situ vital rates of the tiger tail seahorse, H. comes, expanding previous understanding of demographic diversity in reef fishes. We quantified growth, reproduction and survival rates, drawing on mark–recapture intervals from focal observations, underwater visual census and fisheries landings data. The smallest settled individual was 2.7 cm and first benthic cohorts measured 3.0–4.0 cm. Assuming individually variable growth, the mean parameters for the von Bertalanffy growth equation were Linf = 16.7 cm, K = 2.9 year–1 and t0 = 0.03. Physical maturity occurred at 9.3 cm, reproductive activity at 11.6 cm and annual recruitment during the dry, inter-monsoon window from February to May. Size-dependent survivorship ranged from 3.5% to 45.0% year–1 and longevity was ≥2.5 years. In H. comes, characteristics governing population turnover align with opportunistic strategists, whereas reproductive traits align more closely with equilibrium strategists. Non-extractive marine reserves are one management approach that could serve such intermediate strategists, providing refugia for colonisation, while protecting important large, fecund adults.

Comparative review of Pacific salmon survival rates

1995 ◽  
Vol 52 (6) ◽  
pp. 1327-1338 ◽  
Author(s):  
Michael J. Bradford
Keyword(s):  
Life History ◽  
Survival Data ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Survival Rates ◽  
Adult Survival ◽  
Life History Stages ◽  
Comparative Review ◽  
History Of ◽  
The Mean

I collated estimates of survival from the literature for naturally reproducing populations of the five major commercially harvested species of Pacific salmon (Oncorhynchus spp.) and compared the mean and variability of survival across species and life-history stages. The conclusion that survival rates can be described with a lognormal distribution was extended to include both the marine and freshwater stages. Average egg–fry survival of pink (O. gorbuscha), chum (O. keta), and sockeye (O. nerka) salmon was similar (average 7%) but was significantly lower than that of coho salmon (O. kisutch, 19%). The egg–smolt survival of chinook (O. tshawytscha) was much higher than coho or sockeye that also rear in freshwater for similar periods (7 compared with 1–2%). No direct estimates exist for the marine survival rate of naturally spawning chinook stocks; however, from fecundity and freshwater survival data a species average of 1–2% was derived. Across all species freshwater contributes slightly more to total variation in egg–adult survival than does the ocean, and the schedule of mortality during the egg–adult interval depends on the natural history of each species.

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