Lack of relationship between forest edge proximity and nest predator activity in an eastern Canadian boreal forest

2001 ◽  
Vol 31 (1) ◽  
pp. 117-122 ◽  
Author(s):  
Jacques Ibarzabal ◽  
André Desrochers
Keyword(s):  
Predation Risk ◽  
Nest Predation ◽  
Boreal Forests ◽  
Statistical Power ◽  
Abies Balsamea ◽  
Predation Rate ◽  
Agricultural Landscapes ◽  
Forest Edges ◽  
Nest Predator ◽  
Discovery Rates

Nest predation risk often increases near forest edges in agricultural landscapes, but this pattern has rarely been found in forested landscapes. Whether this lack of relationship is general remains unclear, especially because no assessment of statistical power has been published. To (1) assess whether and how far nest predation risk is associated with forest edges and (2) avoid confounding effects of the surrounding landscape, we measured nest predator activity by placing baits at five distances (0, 30, 60, 90, and 120 m) from sharp, rectilinear forest edges that run along extensive tracts of forest. No association was found between distance to forest edges and bait discovery rates (P = 0.7). The lack of edge effect was unlikely to be caused by a lack of statistical power (1 - β > 0.8). However, bait discovery rates were significantly heterogeneous throughout the study area, and ground baits were taken at a greater rate than arboreal baits. Mice, voles, and red squirrels (Tamiasciurus hudsonicus (Erxleben)), all nest predators, were the main users of bait. Red squirrel occurrence, as estimated by playbacks, was higher in black spruce (Picea mariana (Mill.) BSP) than in balsam fir (Abies balsamea (L.) Mill.) stands but was not associated with a high bait predation rate. Our results strengthen support to the hypothesis that nests near open areas in managed boreal forests are not more at risk than forest-interior nests.

scholarly journals Experimentally induced antipredator responses are mediated by social and environmental factors

2019 ◽  
Vol 30 (4) ◽  
pp. 986-992 ◽  
Author(s):  
Frank Groenewoud ◽  
Sjouke A Kingma ◽  
Kat Bebbington ◽  
David S Richardson ◽  
Jan Komdeur
Keyword(s):  
Predation Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Ecological Factors ◽  
Antipredator Defense ◽  
Trade Offs ◽  
Future Reproduction ◽  
Female Investment ◽  
Predator Model ◽  
Nest Predator

AbstractNest predation is a common cause of reproductive failure for many bird species, and various antipredator defense behaviors have evolved to reduce the risk of nest predation. However, trade-offs between current reproductive duties and future reproduction often limit the parent’s ability to respond to nest predation risk. Individual responses to experimentally increased nest predation risk can give insights into these trade-offs. Here, we investigate whether social and ecological factors affect individual responses to predation risk by experimentally manipulating the risk of nest predation using taxidermic mounts in the cooperative breeding Seychelles warbler (Acrocephalus sechellensis). Our results show that dominant females, but not males, alarm called more often when they confront a nest predator model alone than when they do so with a partner, and that individuals that confront a predator together attacked more than those that did so alone. Dominant males increased their antipredator defense by spending more time nest guarding after a presentation with a nest predator, compared with a nonpredator control, but no such effect was found for females, who did not increase the time spent incubating. In contrast to incubation by females, nest guarding responses by dominant males depended on the presence of other group members and food availability. These results suggest that while female investment in incubation is always high and not dependent on social and ecological conditions, males have a lower initial investment, which allows them to respond to sudden changes in nest predation risk.

Parent birds assess nest predation risk: influence of cavity condition and avian nest predator activity

2017 ◽  
Vol 48 (5) ◽  
pp. 691-699
Author(s):  
Jongmin Yoon ◽  
Jung-Shim Jung ◽  
Eun-Jin Joo ◽  
Byung-Su Kim ◽  
Shi-Ryong Park
Keyword(s):  
Predation Risk ◽  
Nest Predation ◽  
Avian Nest ◽  
Nest Predator

scholarly journals Plasticity of parental care under the risk of predation: how much should parents reduce care?

2013 ◽  
Vol 9 (4) ◽  
pp. 20130154 ◽  
Author(s):  
Cameron K. Ghalambor ◽  
Susana I. Peluc ◽  
Thomas E. Martin
Keyword(s):  
Parental Care ◽  
Predation Risk ◽  
Perceived Risk ◽  
Nest Predation ◽  
Behavioural Plasticity ◽  
Risk Of Predation ◽  
Theoretical Predictions ◽  
The Mean ◽  
Parental Provisioning ◽  
Nest Predator

Predation can be an important agent of natural selection shaping parental care behaviours, and can also favour behavioural plasticity. Parent birds often decrease the rate that they visit the nest to provision offspring when perceived risk is high. Yet, the plasticity of such responses may differ among species as a function of either their relative risk of predation, or the mean rate of provisioning. Here, we report parental provisioning responses to experimental increases in the perceived risk of predation. We tested responses of 10 species of bird in north temperate Arizona and subtropical Argentina that differed in their ambient risk of predation. All species decreased provisioning rates in response to the nest predator but not to a control. However, provisioning rates decreased more in species that had greater ambient risk of predation on natural nests. These results support theoretical predictions that the extent of plasticity of a trait that is sensitive to nest predation risk should vary among species in accordance with predation risk.

scholarly journals Evaluation of Spatio-Temporal Patterns of Predation Risk to Forest Grouse Nests in the Central European Mountain Regions

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 316
Author(s):  
Jan Cukor ◽  
Rostislav Linda ◽  
Oddgeir Andersen ◽  
Lasse Frost Eriksen ◽  
Zdeněk Vacek ◽  
...  
Keyword(s):  
Predation Risk ◽  
Red Fox ◽  
Predation Rate ◽  
Forest Edge ◽  
Camera Traps ◽  
Black Grouse ◽  
Mountain Areas ◽  
Artificial Nests ◽  
Common Raven ◽  
Nest Predator

We evaluated the spatiotemporal patterns of predation risk on black grouse nests using artificial nests that were monitored by camera traps in mountain areas with a small extant (Ore Mts.) and already extinct (Jeseníky Mts.) black grouse population. The overall predation rate of artificial nests was 56% and we found significant differences in survival rate courses over time between both study areas (68% Ore Mts. vs. 41%, Jeseníky Mts.). Within the time required for successful egg incubation (25 days), nest survival probability was 0.32 in the Ore Mts. and 0.59 in Jeseníky Mts. The stone marten (Martes foina) was the primary nest predator in both study areas (39% in total), followed by common raven (Corvus corax, 25%) and red fox (Vulpes vulpes, 22%). The proportion of depredated nests did not differ between habitat types (i.e., open forest interior, clearing, forest edge), but we recorded the effect of interaction of study area and habitat. In Ore Mts., the main nest predator was common raven with seven records (37%). The Eurasian jay (Garrulus glandarius) was responsible for most predation attempts in Jeseníky Mts. (five records, i.e., 83%), while in the Ore Mts., most predation attempts were done by red fox (six records, i.e., 38%).

Effect of partial cutting on predation risk to artificial bird nests

1999 ◽  
Vol 29 (12) ◽  
pp. 1911-1915 ◽  
Author(s):  
J Douglas Steventon ◽  
Peter K Ott ◽  
Kenneth L MacKenzie
Keyword(s):  
Predation Risk ◽  
Nest Predation ◽  
Basal Area ◽  
Predation Rate ◽  
Nesting Success ◽  
Partial Cutting ◽  
Artificial Nests ◽  
Detectable Difference ◽  
Predation Rates ◽  
Rule Out

Based on relative abundance data, partial cutting has been suggested as a technique to maintain habitat for birds associated with late-seral forests, but there has been little study of partial cutting effects on nesting success. One of the primary limitations to nesting success is nest predation. We compared predation rates (proportion of nests disturbed in a 14-day period) in partially cut (30 or 60% basal area removal), clearcut, and uncut forests in northwestern British Columbia, in two experiments using ground-placed (1993) and shrub-placed (1998) artificial nests. In the ground-nest experiment there was a very low predation rate (0.06) and no detectable difference among treatments (p = 0.403). In the shrub-nest experiment, there was a 0.36 predation rate and little evidence of treatment differences (p = 0.295). Based on 90% confidence intervals for differences in observed predation rate, the 30% removal clearly did not increase predation risk relative to uncut forest. With the 60% removal, however, we cannot rule out a possible increase in predation risk compared with either uncut forest or clearcuts.

Elevated nest predation risk promotes offspring size variation in birds with prolonged parental care.

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Predation Risk ◽  
Reproductive Cycle ◽  
Perceived Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Size Variation ◽  
Egg Laying ◽  
Offspring Size ◽  
Natural Predation ◽  
Risk Spreading

Predation of offspring is the main cause of reproductive failure in many species, and the mere fear of offspring predation shapes reproductive strategies. Yet, natural predation risk is ubiquitously variable and can be unpredictable. Consequently, the perceived prospect of predation early in a reproductive cycle may not reflect the actual risk to ensuing offspring. An increased variance in investment across offspring has been linked to breeding in unpredictable environments in several taxa, but has so far been overlooked as a maternal response to temporal variation in predation risk. Here, we experimentally increased the perceived risk of nest predation prior to egg-laying in seven bird species. Species with prolonged parent-offspring associations increased their intra-brood variation in egg, and subsequently offspring, size. High risk to offspring early in a reproductive cycle can favour a risk-spreading strategy particularly in species with the greatest opportunity to even out offspring quality after fledging.

scholarly journals Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird

2020 ◽  
Author(s):  
Kristina Noreikienė ◽  
Kim Jaatinen ◽  
Benjamin B. Steele ◽  
Markus Öst
Keyword(s):  
Predation Risk ◽  
Telomere Length ◽  
Clutch Size ◽  
Body Condition ◽  
Nest Predation ◽  
Hatching Success ◽  
Reproductive Investment ◽  
Trade Off ◽  
Relative Telomere Length ◽  
Future Reproduction

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

scholarly journals Evaluating the Performance of a Forest Succession Model to Predict the Long-Term Dynamics of Tree Species in Mixed Boreal Forests Using Historical Data in Northern Ontario, Canada

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1181
Author(s):  
Guy R. Larocque ◽  
F. Wayne Bell
Keyword(s):  
Populus Tremuloides ◽  
Boreal Forests ◽  
Forest Ecosystems ◽  
Forest Succession ◽  
Regional Scale ◽  
Abies Balsamea ◽  
Forest Growth ◽  
Northern Ontario ◽  
Phase Dynamics

Environmental concerns and economic pressures on forest ecosystems have led to the development of sustainable forest management practices. As a consequence, forest managers must evaluate the long-term effects of their management decisions on potential forest successional pathways. As changes in forest ecosystems occur very slowly, simulation models are logical and efficient tools to predict the patterns of forest growth and succession. However, as models are an imperfect representation of reality, it is desirable to evaluate them with historical long-term forest data. Using remeasured tree and stand data from three data sets from two ecoregions in northern Ontario, the succession gap model ZELIG-CFS was evaluated for mixed boreal forests composed of black spruce (Picea mariana [Mill.] B.S.P.), balsam fir (Abies balsamea [L.] Mill.), jack pine (Pinus banksiana L.), white spruce (Picea glauca [Moench] Voss), trembling aspen (Populus tremuloides Michx.), white birch (Betula papyrifera Marsh.), northern white cedar (Thuja occidentalis L.), American larch (Larix laricina [Du Roi] K. Koch), and balsam poplar (Populus balsamefera L.). The comparison of observed and predicted basal areas and stand densities indicated that ZELIG-CFS predicted the dynamics of most species consistently for periods varying between 5 and 57 simulation years. The patterns of forest succession observed in this study support gap phase dynamics at the plot scale and shade-tolerance complementarity hypotheses at the regional scale.

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