Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Population (2)
- Abundance (1)
- Accessable method (1)
- Breeding (1)
- Chick (1)
-
- Communities (1)
- Competition (1)
- Data (1)
- Delayed reproduction (1)
- Demographic synchrony (1)
- Ducks (1)
- Environment (1)
- Evolution (1)
- Greater sage-grouse (1)
- Heterogeneity (1)
- Hierarchical (1)
- Implementing (1)
- Inertia (1)
- Landscape (1)
- Modeling (1)
- Models (1)
- Parasitism (1)
- Recruitment (1)
- Scale (1)
- Scaup (1)
- Seabird (1)
- Sensitivity (1)
- Spatio (1)
- Survival (1)
- Sympatric (1)
Articles 1 - 8 of 8
Full-Text Articles in Life Sciences
Effects Of Landscape-Scale Environmental Variation On Greater Sage-Grouse Chick Survival, Michael R. Guttery, David K. Dahlgren, Terry A. Messmer, John W. Connelly, Kerry P. Reese, Pat A. Terletzky, Nathan Burkepile, David N. Koons
Effects Of Landscape-Scale Environmental Variation On Greater Sage-Grouse Chick Survival, Michael R. Guttery, David K. Dahlgren, Terry A. Messmer, John W. Connelly, Kerry P. Reese, Pat A. Terletzky, Nathan Burkepile, David N. Koons
David N. Koons
Effective long-term wildlife conservation planning for a species must be guided by information about population vital ratesat multiple scales. Greater sage-grouse (Centrocercus urophasianus) populations declined substantially during the twentieth century, largely as a result of habitat loss and fragmentation. In addition to the importance of conserving large tracts of suitable habitat, successful conservation of this species will require detailed information about factors affecting vital rates at both the population and range-wide scales. Research has shown that sage-grouse population growth rates are particularly sensitive to hen and chick survival rates. While considerable information on hen survival exists, there is limited information …
An Accessible Method For Implementing Hierarchal Models With Spatio-Temporal Abundance Data, Beth E. Ross, Mevin B. Hooten, David N. Koons
An Accessible Method For Implementing Hierarchal Models With Spatio-Temporal Abundance Data, Beth E. Ross, Mevin B. Hooten, David N. Koons
David N. Koons
A common goal in ecology and wildlife management is to determine the causes of variation in population dynamics over long periods of time and across large spatial scales. Many assumptions must nevertheless be overcome to make appropriate inference about spatio-temporal variation in population dynamics, such as autocorrelation among data points, excess zeros, and observation error in count data. To address these issues, many scientists and statisticians have recommended the use of Bayesian hierarchical models. Unfortunately, hierarchical statistical models remain somewhat difficult to use because of the necessary quantitative background needed to implement them, or because of the computational demands of …
Integrated Modeling Of Communities: Parasitism, Competition, And Demographic Synchrony In Sympatric Ducks, Guillaume Péron, David N. Koons
Integrated Modeling Of Communities: Parasitism, Competition, And Demographic Synchrony In Sympatric Ducks, Guillaume Péron, David N. Koons
David N. Koons
Functionally similar species often co-occur within an ecosystem, and they can compete for or facilitate each other’s access to resources. The coupled dynamics of such species play an important role in shaping biodiversity and an ecosystem’s resilience to perturbations. Here we study two congeneric North American ducks: Redhead Aythya americana and Canvasback A. vaselineria. Both are largely sympatric during the breeding season, and in addition to competition, facultative parasitic egg-laying can lead to interspecific density dependence. Using multi-population integrated models, we combined capture– recovery data, population surveys, and age ratio data in order to simultaneously estimate the mechanistic drivers of …
Modeling The Midcontinent Population Of Lesser Snow Geese, R.F. Rockwell, Kevin Dufour, Eric Reed, David N. Koons
Modeling The Midcontinent Population Of Lesser Snow Geese, R.F. Rockwell, Kevin Dufour, Eric Reed, David N. Koons
David N. Koons
No abstract provided.
Consequences Of Recruitmentdecisions And Heterogeneity On Age-Specific Breeding Success In A Long-Lived Seabird, L. M. Aubry, David N. Koons, J. Y. Monnat, E. Cam
Consequences Of Recruitmentdecisions And Heterogeneity On Age-Specific Breeding Success In A Long-Lived Seabird, L. M. Aubry, David N. Koons, J. Y. Monnat, E. Cam
David N. Koons
An individual’s age at first reproduction and investment in successive reproductive attempts are involved in mechanisms that can impede somatic repair, resulting in a decline in reproductive abilities with age (reproductive senescence). We used long-term data from the Black-legged Kittiwake, a long-lived seabird, to address the relationship between recruitment age, age-specific breeding success (BS), and reproductive senescence, while accounting for breeding experience and temporal variation in BS. We first detected late-life improvement in BS across all recruitment groups, which we recognized as ‘‘within-generation selection’’ or the selective disappearance of ‘‘frail’’ phenotypes. When such heterogeneity was accurately accounted for, we showed …
Evolution Of Delayed Reproduction Inuncertain Environments: A Life History Perspective, David N. Koons, C. J.E. Metcalf, S. Tuljapurkar
Evolution Of Delayed Reproduction Inuncertain Environments: A Life History Perspective, David N. Koons, C. J.E. Metcalf, S. Tuljapurkar
David N. Koons
Environmental uncertainty alone can select for delayed reproduction; however, its relative role in the evolution of delayed reproduction across life histories is not known. Along a life-history spectrum from low-survival/high-fertility species to high-survival/ low-fertility species, we show that the latter are more likely to evolve delayed reproduction if fertility varies over time. By contrast, if survival varies over time, low-survival life histories are more likely to evolve delays. If there is variation in both survival and fertility, and if this variation is positively associated, the evolutionarily stable reproductive delay is decreased (relative to independent variation in survival and fertility). Conversely, …
Population Inertia And Its Sensitivity Tochanges In Vital Rates And Population Structure, David N. Koons, R. R. Holmes, J. B. Grand
Population Inertia And Its Sensitivity Tochanges In Vital Rates And Population Structure, David N. Koons, R. R. Holmes, J. B. Grand
David N. Koons
Because the (st)age structure of a population may rarely be stable, studies of transient population dynamics and population momentum are becoming ever more popular. Yet, studies of ‘‘population momentum’’ are restricted in the sense that they describe the inertia of population size resulting from a demographic transition to the stationary population growth rate. Although rarely mentioned, inertia in population size is a general phenomenon and can be produced by any demographic transition or perturbation. Because population size is of central importance in demography, conservation, and management, formulas relating the sensitivity of population inertia to changes in underlying vital rates and …
Lesser Scaup Population Dynamics: What Can Belearned From Available Data?, David N. Koons, J. J. Rotella, D. W. Willey, M. Taper, R. G. Clark, S. Slattery, R. W. Brook, R. M. Corcoran, J. R. Lovvorn
Lesser Scaup Population Dynamics: What Can Belearned From Available Data?, David N. Koons, J. J. Rotella, D. W. Willey, M. Taper, R. G. Clark, S. Slattery, R. W. Brook, R. M. Corcoran, J. R. Lovvorn
David N. Koons
Populations of Lesser Scaup (Aythya affinis) have declined markedly in North America since the early 1980s. When considering alternatives for achieving population recovery, it would be useful to understand how the rate of population growth is functionally related to the underlying vital rates and which vital rates affect population growth rate the most if changed (which need not be those that influenced historical population declines). To establish a more quantitative basis for learning about life history and population dynamics of Lesser Scaup, we summarized published and unpublished estimates of vital rates recorded between 1934 and 2005, and developed matrix life-cycle …