Common Loon (Gavia immer)

Evers, David C.; Paruk, James D.; McIntyre, Judith W.; Barr, Jack F.

doi:10.2173/bna.comloo.02

Cited by 44 publications

(28 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This increase is similar to those documented in other populations in Minnesota and Wisconsin (Meyer 2006, Evers 2007. Density-dependent effects can manifest themselves in increased agonistic interactions between adult loons that result in reduced occupancy (Paruk 1999, Piper et al 2000, Evers 2001), direct mortality of adults and chicks (Evers et al 2010), or increased nest failure by indirectly facilitating egg predation (Paruk 2000). As population density approached carrying capacity and suitable habitat became saturated from the 1980s to 2000s, overall nesting success may have declined if loons were forced to use less-suitable nest sites that were more susceptible to flooding or predation (Grear et al 2009).…”

Section: Discussionmentioning

confidence: 99%

Effects of water-level management on nesting success of common loons

Windels¹,

Beever

Paruk

et al. 2013

Jour. Wild. Mgmt.

Self Cite

View full text Add to dashboard Cite

Water‐level management is widespread and illustrates how contemporary climate can interact directly and indirectly with numerous biological and abiotic factors to influence reproductive success of wildlife species. We studied common loons, an iconic waterbird sensitive to timing and magnitude of water‐level changes during the breeding season, using a before‐after‐control‐impact design on large lakes in Voyageurs National Park (Minnesota, USA), to assess the effect of anthropogenic changes in hydroregime on their nesting success and productivity. We examined multiple competing a priori hypotheses in an information‐theoretic framework, and predicted that magnitude of changes in loon productivity would be greater in the Namakan Reservoir, where water‐level management was altered to mimic a more natural hydroregime, than in Rainy Lake, where management remained relatively unchanged. We determined outcomes from 278 nests during 2004–2006 by performing boat‐based visits every 3–5 days, and measuring hydrologic, vegetative, and microtopographic covariates. Relative to comparably collected data for 260 total loon pairs during 1983–1986, productivity (chicks hatched/territorial pair) increased 95% in the Namakan Reservoir between the 2 time periods. Nest success declined in both lakes over the 2 study periods but less so in the Namakan Reservoir than in Rainy Lake. Flooding was a primary cause of nest failures (though second nests were less likely to flood). Nest predation appears to have increased considerably between the 2 study periods. Top‐ranked models suggested that timing of nest initiation, probability of nest flooding, probability of nest stranding, and probability of nest success were each related to 2–4 factors, including date of initiation, timing of initiation relative to peak water levels, changes in the elevation of the nest edge, maximum water‐level change between initiation and peak water levels, and maximum water‐level change between initiation and nest outcome. The top model for all variables except stranding each garnered ≥82% of total model weight. Results demonstrate that water‐level management can be altered to benefit productivity of common loons. However, nuanced interactions between land‐use change, invasive species, human development, recreation, climate change, and recovery of top predators may often complicate both management decisions and interpretation of water‐level impacts on wildlife. © 2013 The Wildlife Society.

show abstract

Section: Discussionmentioning

confidence: 99%

Effects of water-level management on nesting success of common loons

Windels¹,

Beever

Paruk

et al. 2013

Jour. Wild. Mgmt.

Self Cite

View full text Add to dashboard Cite

show abstract

“…We calculated a 95% confidence interval for this detection probability and applied it to observed values of adults, territorial pairs, and unpaired adults in LPC's dataset. We applied only an upper 95% confidence interval to observed values of surviving chicks to account for missed chicks because double counting is an unlikely source of error for unfledged chicks (Evers et al 2010).…”

Section: Population Projectionsmentioning

confidence: 99%

“…Ingested lead fishing tackle has been documented in 28 species of North American birds (Blus 1994, Scheuhammer and Norris 1995, Anderson et al 2000, Scheuhammer et al 2002, Franson et al 2003, as a risk factor for 75 species (U.S. Environmental Protection Agency 1994), and as a leading cause of death for common loons (Gavia immer; Pokras and Chafel 1992, Stone and Okoniewski 2001, Sidor et al 2003, Strom et al 2009, Grade 2011. Because common loons may live for 30 years, do not breed until they are !4 years of age, and have a low fecundity of 0.53 chicks fledged/territorial pair/year on average (Evers et al 2010), population viability is heavily influenced by adult survival (Grear et al 2009); therefore, high rates of lead tackle mortality among adult loons have the potential to adversely affect populations.…”

mentioning

confidence: 99%

“…Intensive monitoring of the state's loon population and mortality allows an assessment of the effects of lead tackle mortality on the population that is not possible for many other species and locations. Given the limited dispersal distances of loons from natal lakes or previous breeding territories to new potential breeding territories (Piper et al 1997, Evers et al 2010, we treated New Hampshire's loons as a closed population.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Population‐level effects of lead fishing tackle on common loons

et al. 2017

View full text Add to dashboard Cite

Poisoning from lead fishing tackle has been identified as the leading cause of mortality in adult common loons (Gavia immer). As a K-selected species, adult survival is a critical component in the population demography of loons, but the population-level effects of mortality from ingested lead tackle on loons have not been quantified. We used a long-term dataset on common loon mortality in New Hampshire, USA, to describe the types of lead tackle ingested by loons, investigate methods of ingestion of lead tackle, document the number and rate of adult mortalities resulting from lead tackle, and test for a population-level effect of lead tackle on the loon population in New Hampshire. Nearly half (48.6%) of collected adult mortalities resulted from lead toxicosis from ingested lead fishing tackle, representing an adjusted annual mortality rate of 1.7 AE 0.6% (SD) of the statewide population. Jigs accounted for 52.6% and sinkers for 38.8% of the archived lead tackle objects removed from loons, a higher proportion of jigs than has been reported in previous studies. The timing of lead tackle mortalities and a high incidence of accompanying non-lead associated fishing gear (hooks, fishing line, leaders, swivels, wire), which peaked in July and August, suggest that loons obtain the majority of lead tackle from current fishing activity rather than from a reservoir of lead tackle on lake bottoms. To project the statewide loon population in the absence of lead fishing tackle as a stressor, we constructed a retrospective population model, which re-inserted loons that died from lead tackle into the population, and used linear regression to test for a population-level effect. We defined a populationlevel effect as a difference in the population growth rate (l). We estimated that lead tackle mortality reduced the population growth rate (l) by 1.4% and the statewide population by 43% during the years of the study. This study suggests that replacing lead fishing sinkers and jigs weighing 28.4 g with non-toxic alternatives would result in an immediate benefit to the loon population in New Hampshire. Ó 2017 The Wildlife Society.

show abstract

“…Several studies have suggested that common loons (Gavia immer) are at risk of elevated dietary mercury (Hg) exposure in portions of their breeding range (reviewed in Evers et al 2010). Altered adult loon nesting behavior (Evers et al 2008), reduced productivity (Barr 1986;Meyer et al 1995Meyer et al , 1998, and altered chick behavior (Nocera and Taylor 1998;Counard 2001) have been associated with elevated Hg exposure.…”

Section: Introductionmentioning

confidence: 99%

Patterns of mercury and selenium exposure in minnesota common loons

Kenow

Houdek

Fara

et al. 2019

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

Common loons (Gavia immer) are at risk of elevated dietary mercury (Hg) exposure in portions of their breeding range. To assess the level of risk among loons in Minnesota (USA), we investigated loon blood Hg concentrations in breeding lakes across Minnesota. Loon blood Hg concentrations were regressed on predicted Hg concentrations in standardized 12‐cm whole‐organism yellow perch (Perca flavescens), based on fish Hg records from Minnesota lakes, using the US Geological Survey National Descriptive Model for Mercury in Fish. A linear model, incorporating common loon sex, age, body mass, and log‐transformed standardized perch Hg concentration representative of each study lake, was associated with 83% of the variability in observed common loon blood Hg concentrations. Loon blood Hg concentration was positively related to standardized perch Hg concentrations; juvenile loons had lower blood Hg concentrations than adult females, and blood Hg concentrations of juveniles increased with body mass. Blood Hg concentrations of all adult common loons and associated standardized prey Hg for all loon capture lakes included in the study were well below proposed thresholds for adverse effects on loon behavior, physiology, survival, and reproductive success. The fish Hg modeling approach provided insights into spatial patterns of dietary Hg exposure risk to common loons across Minnesota. We also determined that loon blood selenium (Se) concentrations were positively correlated with Hg concentration. Average common loon blood Se concentrations exceeded the published provisional threshold. Environ Toxicol Chem 2019;38:524–532. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

show abstract

Common Loon (Gavia immer)

Cited by 44 publications

References 0 publications

Effects of water-level management on nesting success of common loons

Effects of water-level management on nesting success of common loons

Population‐level effects of lead fishing tackle on common loons

Patterns of mercury and selenium exposure in minnesota common loons

Contact Info

Product

Resources

About