USGS Science⌕ Search

SEARCH · USGS Science

Results for “Life”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
USGS2021

The contribution of water radiolysis to marine sedimentary life

Water radiolysis continuously produces H 2 and oxidized chemicals in wet sediment and rock. Radiolytic H 2 has been identified as the primary electron donor (food) for microorganisms in continental aquifers kilometers below Earth’s surface. Radiolytic products may also be significant for sustaining life in subseafloor sediment and subsurface environments of other planets. However, the extent to which most subsurface ecosystems rely on radiolytic products has been poorly constrained, due to incomplete understanding of radiolytic chemical yields in natural environments. Here we show that all common marine sediment types catalyse radiolytic H 2 production, amplifying yields by up to 27X relative to pure water. In electron equivalents, the global rate of radiolytic H 2 production in marine sediment appears to be 1-2% of the global organic flux to the seafloor. However, most organic matter is consumed at or near the seafloor, whereas radiolytic H 2 is produced at all sediment depths. Comparison of radiolytic H 2 consumption rates to organic oxidation rates suggests that water radiolysis is the principal source of biologically accessible energy for microbial communities in marine sediment older than a few million years. Where water permeates similarly catalytic material on other worlds, life may also be sustained by water radiolysis.

Nature Communications↗
USGS2025

Precipitation timing mediates life-stage and population-level associations with climate for an indicator species

Global climate change is contributing to declines in biodiversity, although changes vary across geographic regions and species. The iconic greater sage-grouse (Centrocercus urophasianus; sage-grouse) is central to conservation within the North American sagebrush ecosystem, yet its vulnerability to climate effects remains poorly understood. We used hierarchical models to explore weather and climatic influences on sage-grouse across nearly four decades, focusing first on pattern (population change), then process (demographic life stage). We quantified eight indicators of temperature and/or moisture conditions across time lags of 0–1.5 years leading up to current year breeding activities. Sage-grouse population growth tended to increase following above-average growing season precipitation. Precipitation or drought timing influenced whether process effects were positive or negative. More summer and/or fall moisture corresponded with increases in subsequent year brood and adult survival, while concurrent seasonal drought led to reductions in nest survival. Positive concurrent spring drought associations with adult and brood survival were largely outweighed by positive prior year moisture effects. Density-dependence and indirect effects of precipitation through vegetation and forage resource pathways likely contributed to nuanced responses across life stages. Our research improves mechanistic understanding of this indicator species’ sensitivity to climatic factors, while reinforcing the importance of large-scale conservation initiatives for sagebrush ecosystems.

Scientific Reports↗
USGS2003

Effects of life history variation on size and growth in stream-dwelling Atlantic salmon

A large size variation amongst life histories for stream-dwelling Atlantic salmon Salmo salar was found and the relative effect of life histories on size varied over time. As early as December (age 0+ years), fish that later smolted at age 2+ years were significantly larger than fish that did not smolt at age 2+ years. In contrast, there were no mass differences at age 0+ years between fish that would mature or not at age 1+ years (October). The mass differences between smolts and non-smolts persisted until smolting, and differences between mature and immature fish first appeared in May (age 1+ years). Following September (age 1+ years), there was also a significant interaction between smolting and maturity. Previously mature and immature age 2+ year smolts were not significantly different in size, but immature age 2+ year non-smolts were much lighter than mature age 2+ year non-smolts. Based on mass differences, the apparent 'decision' to smolt occurred c. 5 months before (winter, age 0+ years) the decision to mature (late spring, age 1+ years). In addition to strong seasonal growth variation, sizes of freshwater Atlantic salmon were largely structured by the complex interaction between smolt-age and maturity. ?? 2003 The fisheries Society of the British Isles.

Journal of Fish Biology↗
USGS2014

Annual variation of spawning Cutthroat Trout in a small Western USA stream: A case study with implications for the conservation of potamodromous trout life history diversity

Little is known about the variability in the spatial and temporal distribution of spawning potamodromous trout despite decades of research directed at salmonid spawning ecology and the increased awareness that conserving life history diversity should be a focus of management. We monitored a population of fluvial–resident Bonneville Cutthroat Trout Oncorhynchus clarkii utah in a tributary to the Logan River, Utah, from 2006 to 2012 to gain insight into the distribution and timing of spawning and what factors may influence these spawning activities. We monitored Bonneville Cutthroat Trout using redd surveys with multiple observers and georeferenced redd locations. We documented an extended spawning period that lasted from late April to mid‐July. The onset, median, and end of spawning was best predicted by the mean maximum water temperature during the first 13 weeks of the year ( F = 130. 4, df = 5, R 2 = 0.96, P < 0.0001) with spawning beginning and ending earlier in years that had warmer water temperatures prior to spawning. The distribution of redds was clumped each year and the relative density of redds was greater in a reach dominated by dams constructed by beavers Castor canadensis . Both dam failure and construction appeared to be responsible for creating new spawning habitat that was quickly occupied, demonstrating rapid temporal response to local habitat changes. Bonneville Cutthroat Trout appeared to establish and defend a redd for up to 2 d, and spawning most often occurred between similar‐sized individuals. Spawning surveys for potamodromous trout are an underutilized tool that could be used to better understand the distribution and timing of spawning as well as determine the size and trends of the reproducing portion of populations of management concern. Without efforts to document the diversity of this important aspect of potamodromous trout life history, prioritization of conservation will be problematic.

Utah↗
USGS2020

Determinants and consequences of dispersal in vertebrates with complex life cycles: a review of pond-breeding amphibians

Dispersal is a central process in ecology and evolution. It strongly influences the dynamics of spatially structured populations, by affecting population growth rate and local colonization-extinction processes. Dispersal can also influence evolutionary processes because it determines rates and patterns of gene flow in spatially structured populations and is closely linked to local adaptation. For these reasons, dispersal has received considerable attention from ecologists and evolutionary biologists. However, although it has been studied extensively in taxa such as birds and mammals, much less is known about dispersal in vertebrates with complex life cycles such as pond-breeding amphibians. Over the past two decades, researchers have taken an interest in amphibian dispersal and initiated both fundamental and applied studies, using a broad range of experimental and observational approaches. This body of research reveals complex dispersal patterns, causations and syndromes, with dramatic consequences for the demography and genetics of amphibian populations. In this review, our goals are to (1) redefine and clarify the concept of amphibian dispersal, (2) review current knowledge about the effects of individual (i.e., condition-dependent dispersal) and environmental (i.e., context-dependent dispersal) factors during the three stages of dispersal (i.e., emigration, immigration, transience), (3) identify the demographic and genetic consequences of dispersal in spatially structured amphibian populations, and (4) propose new research avenues to extend our understanding of amphibian dispersal. In particular, we emphasize the need to (1) quantify dispersal rate and distance rigorously using suitable model systems, (2) investigate the genetic basis and dispersal evolution patterns, and (3) examine dispersal-related eco-evolutionary dynamics. These proposed research avenues tap from the recent advances in quantitative and molecular methods and have the potential to improve our understanding of dispersal in organisms with complex life cycles.

The Quarterly Review of Biology↗
USGS2012

Formation of replicating saponite from a gel in the presence of oxalate: implications for the formation of clay minerals in carbonaceous chondrites and the origin of life

The potential role of clay minerals in the abiotic origin of life has been the subject of ongoing debate for the past several decades. At issue are the clay minerals found in a class of meteorites known as carbonaceous chondrites. These clay minerals are the product of aqueous alteration of anhydrous mineral phases, such as olivine and orthopyroxene, that are often present in the chondrules. Moreover, there is a strong correlation in the occurrence of clay minerals and the presence of polar organic molecules. It has been shown in laboratory experiments at low temperature and ambient pressure that polar organic molecules, such as the oxalate found in meteorites, can catalyze the crystallization of clay minerals. In this study, we show that oxalate is a robust catalyst in the crystallization of saponite, an Al- and Mg-rich, trioctahedral 2:1 layer silicate, from a silicate gel at 60°C and ambient pressure. High-resolution transmission electron microscopy analysis of the saponite treated with octadecylammonium (n(C)=18) cations revealed the presence of 2:1 layer structures that have variable interlayer charge. The crystallization of these differently charged 2:1 layer silicates most likely occurred independently. The fact that 2:1 layer silicates with variable charge formed in the same gel has implications for our understanding of the origin of life, as these 2:1 clay minerals most likely replicate by a mechanism of template-catalyzed polymerization and transmit the charge distribution from layer to layer. If polar organic molecules like oxalate can catalyze the formation of clay-mineral crystals, which in turn promote clay microenvironments and provide abundant adsorption sites for other organic molecules present in solution, the interaction among these adsorbed molecules could lead to the polymerization of more complex organic molecules like RNA from nucleotides on early Earth.

Astrobiology↗
USGS2013

The quest for extraterrestrial life: what about the viruses?

Recently, viruses have been recognized as the most numerous entities and the primary drivers of evolution on Earth. Historically, viruses have been mostly ignored in the field of astrobiology due to the view that they are not alive in the classical sense and if encountered would not present risk due to their host-specific nature. What we currently know of viruses is that we are most likely to encounter them on other life-bearing planets; that while some are exquisitely host-specific, many viruses can utilize hundreds of different host species; that viruses are known to exist in our planet's most extreme environments; and that while many do not survive long outside their hosts, some can survive for extended periods, especially in the cold. In our quest for extraterrestrial life, we should be looking for viruses; and while any encountered may pose no risk, the possibility of an encounter with a virus capable of accessing multiple cell types exists, and any prospective contact with such an organism should be treated accordingly.

Astrobiology↗
USGS2018

Do life history traits influence patterns of maternal immune elements in New World blackbirds (Icteridae)?

Avian immunology developed originally by investigating domesticated poultry species (Galliformes), but in recent decades eco-immunological studies of wild bird species have revealed that avian immune systems are more diverse than initially assumed. This study compares six immunological elements in eggs of six species within the same family, the New World blackbirds (Icteridae),whose members differ most notably in two life history parameters, brood parasitism and body size. We measured the maternal immune investment of passive immune components in both yolk and albumen: lysozyme, ovotransferrin, and immunoglobulins (Igs), and LPS-specific Igs. We predicted that brood parasites would have higher levels of immune activity for both innate and adaptive immunity compared with non-brood parasites, and that increased body size could increase microbial exposure of larger animals, resulting in an increase in some adaptive immune responses, such as LPS-specific Igs. We found that brood parasites had significantly higher levels of Igs and lysozyme levels in albumen, but significantly lower levels of Igs in yolk compared with non-brood parasites. Igs in yolk scaled according to body size, with the smallest organisms (the brood parasites) having the lowest levels, and the largest organism (common grackle) having the highest. Our results confirm the findings of other studies of comparative immunity among species in a single taxon that (1) similarities in immune investment cannot be assumed among closely related species and (2) single measures of immune defense cannot be assumed to be indicators of a species’ overall immune strategy, as life history traits can differentially affect immune responses.

North Dakota, Puerto Rico, South Dakota↗
USGS2024

Planktonic to sessile: Drivers of spatial and temporal variability across barnacle life stages and indirect effects of the Pacific Marine Heatwave

Barnacles are a foundation species in intertidal habitats. During the Pacific Marine Heatwave (PMH), intertidal barnacle cover increased in the northern Gulf of Alaska (GoA); however, the role of pelagic larval supply in this increase was unknown. Using long-term monitoring data on intertidal benthic (percent cover) and pelagic larval populations (nauplii and cyprid concentrations), we examined potential environmental drivers (temperature, chlorophyll-a, mixed layer depth) of larval concentration and whether including larval concentration at regional and annual scales improved intertidal barnacle percent cover models in two study regions in the GoA. In both regions, larval concentrations were slightly higher following the PMH. Percent cover models were improved by including cyprid concentrations (but not nauplii), and the effect strength varied by site and tidal elevation. This indicates that larval concentration contributes as a bottom–up driver of benthic barnacle abundance. There is little evidence of a direct effect of the PMH on either life stage. Instead, our results may illustrate the positive feedback between life stages, where higher adult benthic abundance increased larval concentrations, which then supplied more new recruits to the benthos. As heatwaves continue to occur, integrating various data types can provide insights into factors influencing both benthic and pelagic communities.

Alaska↗
USGS2005

Alternative life histories shape brain gene expression profiles in males of the same population

Atlantic salmon (Salmo salar) undergo spectacular marine migrations before homing to spawn in natal rivers. However, males that grow fastest early in life can adopt an alternative 'sneaker' tactic by maturing earlier at greatly reduced size without leaving freshwater. While the ultimate evolutionary causes have been well studied, virtually nothing is known about the molecular bases of this developmental plasticity. We investigate the nature and extent of coordinated molecular changes that accompany such a fundamental transformation by comparing the brain transcription profiles of wild mature sneaker males to age-matched immature males (future large anadromous males) and immature females. Of the ca. 3000 genes surveyed, 15% are differentially expressed in the brains of the two male types. These genes are involved in a wide range of processes, including growth, reproduction and neural plasticity. Interestingly, despite the potential for wide variation in gene expression profiles among individuals sampled in nature, consistent patterns of gene expression were found for individuals of the same reproductive tactic. Notably, gene expression patterns in immature males were different both from immature females and sneakers, indicating that delayed maturation and sea migration by immature males, the 'default' life cycle, may actually result from an active inhibition of development into a sneaker. ?? 2005 The Royal Society.

Proceedings of the Royal Society B: Biological Sci↗
USGS1956

Half-life of Th232 and the branching ratio of Bi212

The half-life of Th 232 has been calculated by determining an absolute gamma-disintegration rate for Tl 208 in equilibrium with Th 232 for three old thorium nitrate salts and one natural thorite sample. The branching ratio, α/ ( α + β ) , for Bi 212 , a necessary parameter in the calculation, was also measured. The half-life of Th 232 was found to be 1.42× 10 10 years within an estimated error of 5%, which is essentially in agreement with the presently accepted value. The branching ratio, α/ ( α + β ) , of Bi 212 was found to be 0.362±0.006, about 7.4% higher than the currently accepted value.

Physical Review↗
USGS2020

Risk of predation on offspring reduces parental provisioning, but not flight performance or survival across early life stages

Developmental responses can help young animals reduce predation risk but can also yield costs to performance and survival in subsequent life stages with major implications for lifetime fitness. Compensatory mechanisms may evolve to offset such costs, but evidence from natural systems is largely lacking. In songbirds, increased nest predation risk should favour reduced provisioning, but also young that fledge (leave their nest) at an earlier age. Both responses can result in fledglings with shorter wings, reduced mobility and decreased survival. Young may compensate for shorter wings developmentally by reallocating resources towards feather development or behaviourally by adjusting flight kinematics or habitat use. However, underfed young may lack the capacity to express these phenotypes due to insufficient resources or an inability to adjust allocation of resources. Using predation risk experiments and 29 years of observational field data, we test whether increased nest predation risk reduces flight performance and survival during the fledgling stage and explore potential mechanisms that might underlie these effects. We show that young from high-risk nests did not leave the nest earlier on average, but wing growth was slower likely due to observed reductions in parental feeding rates. Wings were shorter in high-risk nests when fledglings left the nest early. Yet, fledglings from high-risk nests showed improved flight performance for a given wing length such that flight performance at fledging did not differ between young from high-risk and low-risk nests. Young from high-risk nests may have offset the costs of shorter wings on flight performance by accelerating the emergence of flight feathers from their sheaths to reduce wing porosity, though evidence for this mechanism was mixed. Fledglings from high-risk nests also selected habitat with denser woody vegetation compared with young from low-risk nests. Together, these developmental and behavioural responses seem to mitigate the expected effects of increased nest predation risk on fledgling survival. Ultimately, our results show that offspring predation risk can affect parental provisioning and offspring morphology without major implications for performance and survival in subsequent life stages.

Arizona↗
USGS2019

Variation in selective regimes drives intraspecific variation in life-history traits and migratory behaviour along an elevational gradient

Comparative studies, across and within taxa, have made important contributions to our understanding of the evolutionary processes that promote phenotypic diversity. Trait variation along geographic gradients provides a convenient heuristic for understanding what drives and maintains diversity. Intraspecific trait variation along latitudinal gradients is well-known, but elevational variation in the same traits is rarely documented. Trait variation along continuous elevational gradients, however, provides compelling evidence that individuals within a breeding population may experience different selective pressures. Our objectives were to quantify variation in a suite of traits along a continuous elevational gradient, evaluate whether individuals in the population experience different selective pressures along that gradient and quantify variation in migratory tendency along that gradient. We examined variation in a suite of 14 life-history, morphological and behavioural traits, including migratory tendency, of yellow-eyed juncos along a continuous 1000-m elevational gradient in the Santa Catalina Mountains of Arizona. Many traits we examined varied along the elevational gradient. Nest survival and nestling growth rates increased, while breeding season length, renesting propensity and adult survival declined, with increasing elevation. We documented the migratory phenotype of juncos (partial altitudinal migrants) and show that individual migratory tendency is higher among females than males and increases with breeding elevation. Our data support the paradigm that variation in breeding season length is a major selective pressure driving life-history variation along elevational gradients and that individuals breeding at high elevation pursue strategies that favour offspring quality over offspring quantity. Furthermore, a negative association between adult survival and breeding elevation and a positive association between nest survival and breeding elevation help explain both the downslope and reciprocal upslope seasonal migratory movements that characterize altitudinal migration in many birds. Our results demonstrate how detailed studies of intraspecific variation in suites of traits along environmental gradients can lend new insights into the evolutionary processes that promote diversification and speciation, the causes of migratory behaviour, and how animal populations will likely respond to climate change.

Journal of Animal Ecology↗
USGS2025

Seasonal body mass dynamics mediate life-history trade-offs in a hibernating mammal

1. Energetic acquisition and growth are key traits that affect demography and life-history strategies. Many animals that live in seasonal environments in which food availability fluctuates store energy endogenously as fat in anticipation of food shortage. Fat-storing mammalian hibernators are an extreme example of this strategy where the optimal resolution of resource allocation trade-offs is essential to survival. Hence, these species provide an opportunity to test potential causes and consequences of seasonal body mass dynamics. 2. We used a 12-year dataset with 8753 body mass records from 3351 individually marked northern Idaho ground squirrels ( Urocitellus brunneus ) – a federally threatened hibernator – to meet three objectives: (1) document seasonal body mass changes by sex, age, and reproductive status, (2) test ecological hypotheses to explain spatiotemporal variation in body mass, and (3) document fitness consequences of pre-hibernation body condition via condition-dependent overwinter survival. 3. Squirrels varied substantially in seasonal body mass dynamics. The magnitude (36-155%) and onset (late May to early July) of rapid active-season mass gain varied among demographic groups. Reproductive females acquired the necessary fat stores to survive hibernation later in the active season than did males and non-reproductive females. Moreover, squirrels with better pre-hibernation body condition were more likely to survive to the subsequent year, potentially because they allocated excess energetic reserves to prolonging hibernation via early immergence and thereby reduced predation risk. These results suggest a direct trade-off between current and future reproduction mediated by resource acquisition and allocation, as predicted by life-history theory. 4. Colder active-season temperatures and lower conspecific densities negatively influenced squirrel body condition, possibly via reductions in foraging activity associated with those conditions. These ecological effects on body condition constrain resource allocation and demographic outcomes. As such, our results can help guide research and conservation strategies to benefit hibernating animals.

Idaho↗
USGS2024

Life-history connections to long-term fish population trends in a species-rich temperate river

Fishes exhibit a diverse range of traits encompassing life-history strategies, feeding behaviours and spawning behaviours. These traits mediate fish population responses to changing environmental conditions such as those caused by anthropogenic stressors. The Conasauga River, located in northwestern Georgia and southeastern Tennessee, USA, hosts a diverse assemblage of over 75 species of freshwater fish, some of which are locally or regionally endemic, and many of which are imperilled. Annual monitoring data have shown population declines in multiple fish species of conservation concern in the Conasauga River since at least the 1990s, raising the possibility that other taxa could be declining as well. We quantified temporal changes in fish communities at six shoal sites sampled annually in most years from 1996 to 2022, and asked whether species traits hypothesized to underlie population vulnerability to environmental alteration were correlated with species-specific trends for 32 taxa. We estimated that total counts of fish in annual samples declined by ~2% per year, although declines were uneven among species and generally greater for less abundant taxa. Tests for species traits corresponding to temporal population trends provided evidence that crevice-spawning minnows and smaller-bodied taxa had steeper declines compared with broadcast spawners and larger, longer-lived, more fecund taxa. Lower abundance, reliance on a particular habitat feature, and life-history traits that may limit population resilience to disturbance may all prove useful for identifying riverine fishes at particular risk of future population decline.

Georgia↗
USGS2013

Early indicators of change: divergent climate envelopes between tree life stages imply range shifts in the western United States

Aim To determine if differences in climate envelopes for six coniferous tree species and two life stages (trees and seedlings) suggest a potential for species range contractions, expansions or shifts in response to climate change and if these patterns differ between subalpine (i.e. cool-climate) and montane (i.e. warm-climate) species. Location The dry domain of the western United States. Methods Using data from the Forest Inventory and Analysis National Program, we quantified the relationship between probability of occurrence and climate for adults and seedlings of each species with a Bayesian logistic regression. Assuming that distributional differences between life stages highlight shifting regeneration patterns relative to adult trees, we assessed differences between seedlings and adult trees based on predicted probabilities of occurrence and climate envelope boundaries. Results Differences between occurrence probabilities for seedlings and adults were greatest for montane, as opposed to subalpine, species and along range margins, especially in the southern and western portions of the study area. Climate envelope boundaries of seedlings differed from adult trees most frequently in montane species and often suggested range contractions or range shifts, as opposed to range expansion. Main conclusions Our results indicated that climate-induced contractions and shifts in seedling distribution in response to recent change are already under way and are particularly severe in montane tree species. While adult trees may persist for hundreds of years without significant regeneration, tree species ranges will eventually contract where tree regeneration fails.

Colorado;Idaho;Montana;Utah;Wyoming↗
USGS2004

Testing life history predictions in a long-lived seabird: A population matrix approach with improved parameter estimation

Life history theory and associated empirical generalizations predict that population growth rate (λ) in long-lived animals should be most sensitive to adult survival; the rates to which λ is most sensitive should be those with the smallest temporal variances; and stochastic environmental events should most affect the rates to which λ is least sensitive. To date, most analyses attempting to examine these predictions have been inadequate, their validity being called into question by problems in estimating parameters, problems in estimating the variability of parameters, and problems in measuring population sensitivities to parameters. We use improved methodologies in these three areas and test these life-history predictions in a population of red-tailed tropicbirds ( Phaethon rubricauda ). We support our first prediction that λ is most sensitive to survival rates. However the support for the second prediction that these rates have the smallest temporal variance was equivocal. Previous support for the second prediction may be an artifact of a high survival estimate near the upper boundary of 1 and not a result of natural selection canalizing variances alone. We did not support our third prediction that effects of environmental stochasticity (El Niño) would most likely be detected in vital rates to which λ was least sensitive and which are thought to have high temporal variances. Comparative data-sets on other seabirds, within and among orders, and in other locations, are needed to understand these environmental effects.

Oikos↗
USGS2004

Demographic estimation methods for plants with unobservable life-states

Demographic estimation of vital parameters in plants with an unobservable dormant state is complicated, because time of death is not known. Conventional methods assume that death occurs at a particular time after a plant has last been seen aboveground but the consequences of assuming a particular duration of dormancy have never been tested. Capture–recapture methods do not make assumptions about time of death; however, problems with parameter estimability have not yet been resolved. To date, a critical comparative assessment of these methods is lacking. We analysed data from a 10 year study of Cleistes bifaria , a terrestrial orchid with frequent dormancy, and compared demographic estimates obtained by five varieties of the conventional methods, and two capture–recapture methods. All conventional methods produced spurious unity survival estimates for some years or for some states, and estimates of demographic rates sensitive to the time of death assumption. In contrast, capture–recapture methods are more parsimonious in terms of assumptions, are based on well founded theory and did not produce spurious estimates. In Cleistes , dormant episodes lasted for 1–4 years (mean 1.4, SD 0.74). The capture–recapture models estimated ramet survival rate at 0.86 (SE∼0.01), ranging from 0.77–0.94 (SEs≤0.1) in any one year. The average fraction dormant was estimated at 30% (SE 1.5), ranging 16–47% (SEs≤5.1) in any one year. Multistate capture–recapture models showed that survival rates were positively related to precipitation in the current year, but transition rates were more strongly related to precipitation in the previous than in the current year, with more ramets going dormant following dry years. Not all capture–recapture models of interest have estimable parameters; for instance, without excavating plants in years when they do not appear aboveground, it is not possible to obtain independent time-specific survival estimates for dormant plants. We introduce rigorous computer algebra methods to identify the parameters that are estimable in principle. As life-states are a prominent feature in plant life cycles, multistate capture–recapture models are a natural framework for analysing population dynamics of plants with dormancy.

Oikos↗