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At least 397 records · Page 22Linked to original sources

USGS1986

Reproductive success and heavy metal contamination in Rhode Island common terns

Common tern cIutch size, reproductive success and growth of young recorded from an abandoned barge on the Providence River, an area of heavy metal contamination, were equal to, or greater than, .from less contaminated areas. Concentrations of copper and zinc were higher in livers of nestling terns from the Providence River than from other, less contaminated, areas. However, concentrations of magnesium, manganese, and iron and the frequency of nickel were equal, or lower, at Providence than other, less contaminated, locations. Among-colony trends in residues of copper, zinc and nickel in prey samples were similar to trends .found in nestling livers. Uric acid concentrations in nestling blood were twice as high in the Providence River than another colony and may have resulted from moderate levels of chromium in the diet.

Environmental Pollution (Series A)↗

USGS2012

Will inundation and salinity levels associated with projected sea level rise reduce the survival, growth, and reproductive capacity of Sarcocornia pacifica (pickleweed)?

In the San Francisco Bay Estuary, CA, USA, sea level rise (SLR) is projected to increase by 1.4 m during the next 90 years resulting in increased inundation and salt water intrusion up-estuary. Since inundation and salinity are critical factors that drive vegetation structure and composition in coastal wetlands, we asked whether inundation and salinity levels associated with SLR would reduce the survival, growth, and reproductive capacity of a dominant halophyte, Sarcocornia pacifica (pickleweed). We conducted a 4 × 4 factorial greenhouse experiment to examine the effects of a range of inundation periods (25, 50, 75, and 100%) and water salinities (0, 10, 20, 30 psu) on individual S. pacifica adults and seedlings. We found that inundation and salinity treatments affected the height of adults and seedlings combined. When examined separately, adult height was negatively affected by inundation ≥75%, while seedling height was affected by the interaction of both inundation and salinity. Adult belowground biomass was negatively affected by complete inundation. Seedling aboveground biomass decreased 46% at the highest salinity (30 psu) and belowground biomass decreased at salinities ≥20 psu. Adult flower production was not affected by treatments but was reduced by 38% at 30 psu salinity for seedlings. While adult survival was 99%, seedling survival was 56% with greatest mortality at low (25%) inundation, possibly because their roots were more susceptible to desiccation. Vegetation structure of the marsh platform comprised of S. pacifica adults will be susceptible to greater inundation rates associated with SLR. Our results suggest that adults may grow less tall, thus altering the vegetation structure and likely the tidal marsh wildlife that rely on these habitats.

Aquatic Botany↗

USGS2017

Investigating the influence of nitrate nitrogen on post-smolt Atlantic salmon Salmo salar reproductive physiology in water recirculation aquaculture systems

A major issue affecting land-based, closed containment Atlantic salmon Salmo salar growout production in water recirculation aquaculture systems (RAS) is precocious male maturation, which can negatively impact factors such as feed conversion, fillet yield, and product quality. Along with other water quality parameters, elevated nitrate nitrogen (NO 3 -N) has been shown to influence the reproductive development and endogenous sex steroid production in a number of aquatic animal species, including Atlantic salmon. We sought to determine whether elevated NO 3 -N in RAS can influence early maturation in post-smolt Atlantic salmon in an 8-month trial in replicated freshwater RAS. Post-smolt Atlantic salmon (102 ± 1 g) were stocked into six RAS, with three RAS randomly selected for dosing with high NO 3 -N (99 ± 1 mg/L) and three RAS set for low NO 3 -N (10 ± 0 mg/L). At 2-, 4-, 6-, and 8-months post-stocking, 5 fish were randomly sampled from each RAS, gonadosomatic index(GSI) data were collected, and plasma was sampled for 11-ketotestosterone (11-KT) quantification. At 4- and 8-months post-stocking, samples of culture tank and spring water (used as “makeup” or replacement water) were collected and tested for a suite of 42 hormonally active compounds using liquid chromatography/mass spectrometry , as well as for estrogenicity using the bioluminescent yeast estrogen screen (BLYES) reporter system. Finally, at 8-months post-stocking 8–9 salmon were sampled from each RAS for blood gas and chemistry analyses, and multiple organ tissues were sampled for histopathology evaluation. Overall, sexually mature males were highly prevalent in both NO 3 -N treatment groups by study’s end, and there did not appear to be an effect of NO 3 -N on male maturation prevalence based on grilse identification, GSI, and 11-KT results, indicating that other culture parameters likely instigated early maturation. No important differences were noted between treatment groups for whole blood gas and chemistry parameters, and no significant tissue changes were noted on histopathology. No hormones, hormone conjugates, or mycotoxins were detected in any water samples; phytoestrogens were generally detected at low levels but were unrelated to NO 3 -N treatment. Finally, low-level estrogenicity was detected in RAS water, but a NO 3 -N treatment effect could not be determined. The major findings of this study are i) the NO 3 -N treatments did not appear to be related to the observed male maturation, and ii) the majority of hormonally active compounds were not detectable in RAS water.

Aquacultural Engineering↗

USGS2006

Dietary exposure of largemouth bass to OCPs changes expression of genes important for reproduction

Dieldrin and p,p???-DDE are ubiquitous contaminants known to act as endocrine disruptors, causing impaired development and reproduction in fish and wildlife. In order to elucidate the mechanisms by which dieldrin and p,p???-DDE cause endocrine disruption in largemouth bass (Micropterus salmoides), fish were exposed subchronically through the diet to both contaminants. Following 120 days of exposure, p,p???-DDE decreased estradiol in females, but increased 11-ketotestosterone in both sexes. Dieldrin on the other hand, decreased estradiol and 11-ketotestosterone in both sexes. Both pesticides also altered steady state mRNA expression levels of a set of genes chosen to represent three possible mechanisms of endocrine disruption: (1) direct interaction with soluble sex steroid receptors, (2) biosynthesis of endogenous sex hormones, and (3) metabolism of endogenous hormones. p,p???-DDE acted as a weak estrogen, increasing the expression of vitellogenin and estrogen receptor ?? in the liver. p,p???-DDE also altered the expression of genes involved in the synthesis of endogenous hormones as well as their metabolism. Dieldrin, on the other hand, only altered expression of vitellogenin and not estrogen receptor ??. Dieldrin also altered the expression of genes involved in hormone synthesis and metabolism, and it dramatically lowered plasma hormone levels. Both pesticides targeted expression of genes involved in all three modes of action, suggesting that they each have multiple modes of action. ?? 2006 Elsevier B.V. All rights reserved.

Aquatic Toxicology↗

USGS2008

Effects of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in zebrafish: General and reproductive toxicity

Mixed-sex populations of young adult zebrafish (???2-month-old) were exposed to measured RDX concentrations of 0, 1 or 9.6 ppm for up to 12 weeks followed by a 15-day rearing period in untreated water. RDX caused high mortality at 9.6 ppm, with most deaths occurring within the first 8 weeks of exposure. RDX at 9.6 ppm caused lower body weights at 4 and 8 weeks of exposure; and at 1 ppm, lower body weight was observed only at 4 weeks. Fish length was not affected by treatment at any time during the exposure period. The bioconcentration factor for RDX seemed to be influenced by time of exposure but not by water RDX concentration; its overall values were 1.01 ?? 0.13, 0.91 ?? 0.06 and 2.23 ?? 0.04 at 4, 8 weeks and 12 weeks, respectively. RDX was not detected in fish collected after the 15-day recovery period. In a separate experiment, adult females and males were separately exposed to RDX at measured concentrations of 0, 0.5 and 3.2 ppm for a period of 6 weeks. Reproductive performance was evaluated by biweekly breeding of the fish and measuring packed-egg volume (PEV) as index of fecundity. At 0.5 ppm, RDX caused elevated PEV levels relative to the control value at 2 weeks but not at 4 or 6 weeks, whereas no significant effects were noted at 3.2 ppm. Egg fertilization and embryo hatching rates were not affected by RDX at any of the concentrations tested. In conclusion, RDX at sublethal concentrations causes short-term negative effects on growth and, at 0.5 ppm, positive effects on fecundity. ?? 2008 Elsevier Ltd.

Chemosphere↗

USGS2018

Quantifying population-level effects of water temperature, flow velocity and chemical-induced reproduction depression: A simulation study with smallmouth bass

Evaluating stochastic abiotic factors and their combined effects on fish and wildlife populations have been challenging in environmental sciences. Contributing to this challenge is the paucity of data describing how observations made on individuals related to exposure to chemical compounds ultimately effect population vital rates, and how this exposure interacts with other abiotic drivers. Using three smallmouth bass populations in Pennsylvania as a case study, we explored both single-factor and combined effects of water temperature, flow velocity and chemical exposure on populations through a model simulation. Although there are many pathways through which chemicals can affect population vital rates, we focused on one where chemical exposure leads to reduced reproduction. Among the three populations considered, two (the Juniata and Susquehanna populations) have experienced adverse health, including the potential adverse effects of environmental stress and chemical contamination that may cause disease and mortality of young-of-year (YOY), various skin lesions and a high prevalence of intersex or testicular oocytes in adults. The third population (The Alleghany population) has not encountered mortality events of YOY and intersex prevalence is much lower. The simulation involved projecting populations using a length-based model under different environmental conditions. In the simulations, abiotic factors influenced population dynamics through their impacts on growth, survival and recruitment. Response to the same environmental stress varied by population and life-stage of the species. Factors affecting young adult and adult life-stages had great influence on proportional stock density (PSD) and the probability of having PSD within the suggested range (PSD probability). Increases in water temperature had a negative effect and dominant role in the combined effect on population size structure (e.g., PSD and PSD probability) – increases in flow velocity during the spring season also had a negative effect on abundance. Populations with high recruitment rates sustained relatively large population size, even under high water temperature and/or high flow velocity, which suggests that factors and management strategies that benefit recruitment (such as reduced chemical contaminants) may compensate for the negative effects of warming water temperatures and high spring flow velocity on population size.

Ecological Modelling↗

USGS2009

Relationships between hepatic trace element concentrations, reproductive status, and body condition of female greater scaup

We collected female greater scaup ( Aythya marila ) on the Yukon–Kuskokwim Delta, Alaska during two breeding seasons to determine if concentrations of 18 trace elements in livers and eggs were elevated and if hepatic concentrations correlated with body condition or affected reproductive status. Fifty-six percent, 5%, and 42% of females, respectively, had elevated hepatic cadmium (Cd: >3 μg g −1 dry weight [dw]), mercury (Hg: >3 μg g −1 dw), and selenium (Se: >10 μg g −1 dw). Somatic protein and lipid reserves were not correlated with hepatic Cd or Hg, but there was a weak negative correlation between protein and Se. Hepatic Cd, Hg, and Se were similar in females that had and had not initiated egg production. In a sample of six eggs, 33% and 100%, respectively, contained Se and Hg, but concentrations were below embryotoxicity thresholds. We conclude that trace element concentrations documented likely were not adversely impacting this study population.

Environmental Pollution↗

USGS2018

Examination of contaminant exposure and reproduction of ospreys (Pandion haliaetus) nesting in Delaware Bay and River in 2015

A study of ospreys ( Pandion haliaetus ) nesting in the coastal Inland Bays of Delaware, and the Delaware Bay and Delaware River in 2015 examined spatial and temporal trends in contaminant exposure, food web transfer and reproduction. Concentrations of organochlorine pesticides and metabolites, polychlorinated biphenyls (PCBs), coplanar PCB toxic equivalents, polybrominated diphenyl ethers (PBDEs) and other flame retardants in sample eggs were generally greatest in the Delaware River. Concentrations of legacy contaminants in 2015 Delaware Bay eggs were lower than values observed in the 1970s through early 2000s. Several alternative brominated flame retardants were rarely detected, with only TBPH [bis(2-ethylhexyl)-tetrabromophthalate)] present in 5 of 27 samples at <5 ng/g wet weight. No relation was found between p,p ′-DDE, total PCBs or total PBDEs in eggs with egg hatching, eggs lost from nests, nestling loss, fledging and nest success. Osprey eggshell thickness recovered to pre-DDT era values, and productivity was adequate to sustain a stable population. Prey fish contaminant concentrations were generally less than those in osprey eggs, with detection frequencies and concentrations greatest in white perch ( Morone americana ) from Delaware River compared to the Bay. Biomagnification factors from fish to eggs for p,p ′-DDE and total PCBs were generally similar to findings from several Chesapeake Bay tributaries. Overall, findings suggest that there have been improvements in Delaware Estuary waterbird habitat compared to the second half of the 20th century. This trend is in part associated with mitigation of some anthropogenic contaminant threats.

Delaware Bay and River↗

USGS1986

Effect of anosmia on reproduction in male and female wolves (Canis lupus)

Anosmia was produced in two female and three male wolves by transection of the olfactory peduncle and was confirmed by their inability to detect meat, urine, feces, anal-gland secretions, and fish emulsion. All operated animals continued to investigate the environment with their noses, to interact normally with other pack members, and to feed at levels which maintained presurgical body weights. No effect was found on reproductive physiology (females: estradiol or progesterone concentrations, ovulation, pregnancy or parturition; males: testosterone, testicular recrudescence or sperm numbers, motility or maturation). One anosmic female became dominant and although she urine-marked with a flexed leg, the rate was lower than typical for dominant females and perhaps contributed to her failure to pair-bond with the dominant male. One anosmic male raised-leg-urinated while competing for pack dominance and when kenneled away from other males. Precopulatory, copulatory, and maternal behavior were observed for one anosmic female and appeared normal. However, neither male that was sexually naive before surgery showed interest in proestrous or estrous females. The possibility that secondary degeneration of brain regions mediating sexual behavior was responsible for the failure of these males to respond was not supported. Not only was the lack of male sexual response the only serious deficit following transection, but the male which was sexually experienced prior to surgery did copulate successfully during his second postoperative breeding season despite continued anosmia. Chemosensory priming from female urine during the protracted proestrous phase, as well as urinary and vaginal odors during estrus, appear to be critical for induction of full sexual potency in sexually naive males. The importance of urine and vaginal secretions in the sexual response of experienced males is uncertain.

Behavioral and Neural Biology↗

USGS2017

Reproductive ecology, spawning behavior, and juvenile distribution of Mountain Whitefish in the Madison River, Montana

Mountain Whitefish Prosopium williamsoni were historically common throughout much of the U.S. Intermountain West. However, within the last decade Mountain Whitefish have exhibited population-level declines in some rivers. In the Madison River, Montana, anecdotal evidence indicates Mountain Whitefish abundance has declined and the population is skewed toward larger individuals, which is typically symptomatic of recruitment problems. Describing reproductive development, spawning behavior, and juvenile distribution will form a foundation for investigating mechanisms influencing recruitment. We collected otoliths and gonadal samples from fish of all size-classes to characterize fecundity, age at maturity, and spawning periodicity. We implanted radio tags in mature Mountain Whitefish and relocated tagged fish in autumn 2012–2014. Timing of spawning was determined from spawning status of captured females and from density of eggs collected on egg mats. In spring 2014, we seined backwater and channel sites to describe age-0 whitefish distribution. Mountain Whitefish were highly fecund (18,454 eggs/kg body weight) annual spawners, and age at 50% maturity was 2.0 years for males and 2.6 years for females. In 2013 and 2014, spawning occurred between the third week of October and first week of November. During spawning, spawning adults and collected embryos were concentrated in the downstream 26 km of the study site, a reach characterized by a complex, braided channel. This reach had the highest CPUE of age-0 Mountain Whitefish, and the percentage of spawning adults in the 25 km upstream from a sampling site was positively associated with juvenile CPUE. Within this reach, age-0 Mountain Whitefish were associated with silt-laden backwater and eddy habitats. Future investigations on mechanisms influencing recruitment should be focused on the embryological phase and age-0 fish.

Montana↗

USGS1989

Seasonal reproductive development of Lampsilis cardium, Amblema plicata plicata, and Potamilus alatus

Adult specimens of three species of freshwater mussels common to the upper Mississippi River were examined histologically to determine seasonal patterns of development in gametogenesis and release of glochidia. Full maturation of gonadal materials in Lampsilis cardium (formerly L. ovata ventricosa ), a long-term breeder, occurred when ambient river temperatures reached 24° to 26°C, between late July and early August. By mid-August, glochidia were present in the marsupia. Glochidia were released from late May through mid-June of the following year once water temperatures reached 20°C. The long-term breeder Potamilus alatus demonstrated full gonadal maturation earlier than seen in L. cardium with reproduction completed by late July (26°C). Glochidia of P. alatus were released over a period similar to that observed for L. cardium , late May through early July of the following year. Fully mature Amblema plicata plicata , a short-term breeder, were collected from late May through early July (18° to 21°C). Glochidia were were released from early June to early August of the same year.

Journal of Freshwater Ecology↗

USGS2016

Assigning sex and reproductive stage to adult Lake Sturgeon using ultrasonography and common morphological measurements

Sex determination of fish species is difficult to assess when sexual dimorphism and gametes are not apparent. For threatened and endangered fish species, noninvasive techniques are needed when determining sex to minimize stress and the potential for mortality. We evaluated the use of a portable ultrasound unit to determine sex of Lake Sturgeon Acipenser fulvescens in the field. Ultrasound images were collected from 9 yellow-egg (F2, F3), 32 black-egg (F4, F5), and 107 fully developed male (M2) Lake Sturgeon. Two readers accurately assigned sex to 88–96% of fish, but accuracy varied in relation to maturity stage. Black-egg females and fully developed males were correctly identified for 89–100% of the fish sampled, while these two readers identified yellow-egg females only 33% and 67% of the time. Time spent collecting images ranged between 2 and 3 min once the user was comfortable with operating procedures. Discriminant analysis revealed the total length : girth ratio was a strong predictor of sex and maturity, correctly classifying 81% of black-egg females and 97% of the fully developed males. However, yellow-egg females were incorrectly classified on all occasions. This study shows the utility of using ultrasonography and a total length : girth ratio for sex determination of Lake Sturgeon in later reproductive stages around the spawning season.

Michigan, Ontario↗

USGS1988

Reproduction in black-crowned night-herons fed selenium

Agricultural and industrial practices can produce wastewater that contains high concentrations of selenium, a naturally-occurring trace element. Selenium entering aquatic systems through wastewater inflow can accumulate in aquatic food chains to levels that may be toxic to fish and wildlife species. Mallard reproduction is known to be adversely affected by 10 ppm selenium in the diet (containing 7–10 percent moisture, in the form of selenomethionine); however, hatching success of eggs laid by black-crowned night-herons fed a 10 ppm selenium diet, as selenomethionine, in this study was not different from eggs laid by herons fed an unsupplemented diet (0.1 ppm selenium). Organ weights, hemoglobin concentrations, hematocrits, eggshell thickness, and shell thickness did not differ between controls and herons receiving 10 ppm selenium. Developmental malformations commonly associated with selenium exposure in other birds were not observed in heron embryos or hatchlings in the 10 ppm group. However, three-day-old hatchlings from herons fed 10 ppm selenium had shorter radius-ulna and femur lengths and higher liver malondialdehyde concentrations than controls. Selenium residues in heron eggs were lower than those reported in mallards fed the same amount of selenium. Results of this study suggest that herons are less sensitive to the toxic effects of selenium than mallards. Other hypotheses are also considered to explain the different responses of the two species.

Lake and Reservoir Management↗

USGS2019

Does vegetation change over 28 years affect habitat use and reproductive success?

Individuals should prefer and use habitats that confer high fitness, but habitat use is not always adaptive. Vegetation in natural landscapes changes gradually and the ability of species to adaptively adjust their habitat use to long-term changes is largely unstudied. We studied nest patch and territory use over 28 yr in Orange-crowned Warblers ( Oreothlypis celata ) in a system that has undergone natural long-term changes in vegetation. Abundance of maple ( Acer grandidentatum ), its preferred nesting habitat, gradually declined from 1987 to 2015. We examined whether habitat use and its fitness consequences changed as the availability of preferred habitat decreased. We used resource selection function models to determine changes over time in the probability of using a nest patch given available patches, and the probability of using a territory given available territories. We estimated nest survival to evaluate changes over time in the fitness consequences of nest patch use. We also compared habitat use (nest patch and territory) and fitness (nest survival) between areas with naturally reduced abundance of maple and experimentally increased abundance of maple (fenced areas). Nest patch use depended on maple abundance and did not change drastically across 28 yr, even though the availability of preferred maple patches decreased over time. In contrast, nest survival tended to decrease over time. We did not see differences in nest patch use and nest survival between unfenced and fenced areas, unlike territory use, which increased with the abundance of maple in fenced areas and decreased in unfenced areas. Our study depicts one example of relatively unchanged habitat use in the face of decreased availability of preferred vegetation across years, with a resulting decrease in reproductive success. Investigating changes in habitat use and fitness consequences for animals exposed to long-term habitat change is necessary to understand adaptive behavioral responses.

Arizona↗

USGS2000

Nesting habitat and reproductive success of southwestern riparian birds

Vegetation structure and floristic composition strongly influence the structure of bird communities. To assess the influence of vegetation and other environmental characteristics on songbirds, we quantified nest-site characteristics and reproductive success of a riparian songbird community in Arizona. Although we found interspecific variation in characteristics associated with nest sites, we identified two suites of species that chose sites with similar characteristics. These “nest groups” were explained largely by nest height and characteristics of nest trees. Overall, nest success was low for songbirds in this community, and averaged 23%. The most common cause of nest failure was predation (81%), although brood parasitism by Brown-headed Cowbirds ( Molothrus ater ) was highest at nests of Bell's Vireos ( Vireo bellii ) (29%). No vegetation or environmental features were associated with the likelihood of cowbird parasitism for any species; nest success for Bell's Vireos was negatively associated with the amount of netleaf hackberry ( Celtis reticulata ) in the understory. Arizona sycamore ( Platanus wrightii ) and netleaf hackberry trees contained 41% and 17% of all nests, respectively, and therefore provide critically important nesting substrates for birds in this rare yet diverse vegetation community.

Arizona↗

USGS2025

Manipulation of the Symbiodiniaceae microbiome confers multigenerational impacts on symbioses and reproductive ecology of its Exaiptasia diaphana host

Symbiodiniaceae-associated microbiota strongly influence cnidarian symbioses. We systematically reduced the bacterial and fungal communities associated with Symbiodiniaceae to study potential effects on the cnidarian holobiont Exaiptasia diaphana (Aiptasia). Clonal anemones were inoculated with xenic Breviolum minutum (SSB01) and microbiome-manipulated cultures after antibacterial or antifungal treatment. The asexual reproduction of pedal laceration allowed for three generations of clonal aposymbiotic Aiptasia to be utilised in this study, from the initial adult generation (G0), to the first (G1), and second (G2) generation. We inoculated small and large G1 Aiptasia with SSB01 algae and monitored onset of symbiosis, rate of algal proliferation, and holobiont characteristics. Sequencing the 16S and 18S rRNA gene regions identified significant differences in the bacterial and fungal communities of the G0 and G1 generations, alongside differences between the size classes of small and large G1 anemones. The microbiome of larger G1 individuals was distinct to the smaller G1 anemones, suggesting a microbiome maturation process. Control Breviolum minutum cultures exhibited a significantly greater proliferation rate in large G1 anemones when compared to antibacterial or antifungal treated cultures, whereas the opposite trend was documented in the small G1 anemones. Although no differences were observed between algal photochemical parameters, or the growth and polyp activity of G1 juveniles, we observed a significant influence in the production of G2 clones between treatments. Overall, we provide strong ecological implications of manipulating Symbiodiniaceae microbiome, not for the algae themselves, but for the maturation of the host Aiptasia, as well as for the cnidarian holobiont over multiple generations.

The ISME Journal↗

USGS2021

The ecology and evolution of synchronized reproduction in long-lived plants

Populations of many long-lived plants exhibit spatially synchronized seed production that varies extensively over time, so that seed production in some years is much higher than on average, while in others, it is much lower or absent. This phenomenon termed masting or mast seeding has important consequences for plant reproductive success, ecosystem dynamics and plant–human interactions. Inspired by recent advances in the field, this special issue presents a series of articles that advance the current understanding of the ecology and evolution of masting. To provide a broad overview, we reflect on the state-of-the-art of masting research in terms of underlying proximate mechanisms, ontogeny, adaptations, phylogeny and applications to conservation. While the mechanistic drivers and fitness consequences of masting have received most attention, the evolutionary history, ontogenetic trajectory and applications to plant–human interactions are poorly understood. With increased availability of long-term datasets across broader geographical and taxonomic scales, as well as advances in molecular approaches, we expect that many mysteries of masting will be solved soon. The increased understanding of this global phenomenon will provide the foundation for predictive modelling of seed crops, which will improve our ability to manage forests and agricultural fruit and nut crops in the Anthropocene.

Philosophical Transactions of the Royal Society B:↗

USGS2019

Effects of life history and reproduction on recruitment time lags in reintroductions of rare plants

Reintroductions are important components of conservation and recovery programs for rare plant species, but their long‐term success rates are poorly understood. Previous reviews of plant reintroductions focused on short‐term (e.g., ≤3 years) survival and flowering of founder individuals rather than on benchmarks of intergenerational persistence, such as seedling recruitment. However, short‐term metrics may obscure outcomes because the unique demographic properties of reintroductions, including small size and unstable stage structure, could create lags in population growth. We used time‐to‐event analysis on a database of unusually well‐monitored and long‐term (4–28 years) reintroductions of 27 rare plant species to test whether life‐history traits and population characteristics of reintroductions create time‐lagged responses in seedling recruitment (i.e., recruitment time lags [RTLs]), an important benchmark of success and indicator of persistence in reintroduced populations. Recruitment time lags were highly variable among reintroductions, ranging from <1 to 17 years after installation. Recruitment patterns matched predictions from life‐history theory with short‐lived species (fast species) exhibiting consistently shorter and less variable RTLs than long‐lived species (slow species). Long RTLs occurred in long‐lived herbs, especially in grasslands, whereas short RTLs occurred in short‐lived subtropical woody plants and annual herbs. Across plant life histories, as reproductive adult abundance increased, RTLs decreased. Highly variable RTLs were observed in species with multiple reintroduction events, suggesting local processes are just as important as life‐history strategy in determining reintroduction outcomes. Time lags in restoration outcomes highlight the need to scale success benchmarks in reintroduction monitoring programs with plant life‐history strategies and the unique demographic properties of restored populations. Drawing conclusions on the long‐term success of plant reintroduction programs is premature given that demographic processes in species with slow life‐histories take decades to unfold.

Conservation Biology↗