Dynamics of ground-nest egg depredation by rodents in a mixed-wood forest

2020 ◽  
Vol 98 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Jeremie Bouffard ◽  
Dany Garant ◽  
Patrick Bergeron
Keyword(s):  
Predation Risk ◽  
Deciduous Forest ◽  
Fagus Grandifolia ◽  
Motion Sensing ◽  
Cyanocitta Cristata ◽  
Artificial Nests ◽  
Tamias Striatus ◽  
Local Abundance ◽  
Rodent Populations ◽  
Forest Habitats

Predation is a leading cause of nest failure in birds, which has significant consequences on their population dynamics. Rodents commonly prey on nests in deciduous forest habitats. This has important implications considering how rodent populations fluctuate with changes in resource availability, such as synchronized but intermittent tree-seed production (mast). In this study, we investigated ground-nest egg predation by rodents over 2 years characterized by high and low beech (Fagus grandifolia Ehrh.) seed availability (mast vs. no-mast years). We used artificial nests monitored by motion-sensing cameras on a study site where eastern chipmunk (Tamias striatus (Linnaeus, 1758)) local abundance was known. We placed the artificial nests in areas of high and low chipmunk abundance as proxy of predation risk. Blue Jays (Cyanocitta cristata (Linnaeus, 1758)) depredated the most eggs overall, but rodent population and egg depredation increased in 2018 following the 2017 mast. However, chipmunks were minor predators and their local abundance did not reflect predation risk. Our results highlight the complexity of predation dynamics on ground-nesting birds and the importance of studying them locally and over multiple years.

Vegetation height and egg coloration differentially affect predation rate and overheating risk: an experimental test mimicking a ground-nesting bird

2012 ◽  
Vol 90 (6) ◽  
pp. 694-703 ◽  
Author(s):  
H. Gillis ◽  
B. Gauffre ◽  
R. Huot ◽  
V. Bretagnolle
Keyword(s):  
Predation Risk ◽  
Breeding Season ◽  
Nest Site Selection ◽  
Artificial Nests ◽  
Vegetation Height ◽  
Selective Pressures ◽  
Wide Range ◽  
Nest Microclimate ◽  
Egg Coloration ◽  
Ground Nesting

Avian eggs need to be laid in protected environments to develop and survive. Nest predation is known as the main cause of breeding failure for many birds, but nest microclimate conditions are also important for embryo development. These two selective pressures are particularly marked in ground-nesting birds. Vegetation height has been shown to be a critical factor for nest-site selection in ground-nesting birds because it can counteract predation and overheating simultaneously. It is therefore difficult to disentangle the respective influences of these risks on selection of a particular nest vegetation height. To develop a conceptual framework for understanding and predicting the relative effects of vegetation on predation and nest microclimate during a breeding season, we used vegetation height to manipulate differentially these two risks. We therefore exposed artificial nests to a wide range of vegetation heights, replicated the experimental tests during spring, and manipulated egg color to estimate predation risk. We confirmed that tall vegetation is relevant to protect unattended eggs against both risks. Whereas predation risk is stable for a given vegetation height, overheating risk presents inter- and intra-seasonal variations. Therefore, over a breeding season, for a given vegetation height, the respective strengths of the two risks are unbalanced and depends on egg coloration. The breeding strategy of ground-nesting birds thus should have been shaped by both selective pressures, but the ultimate choice may depend on the species-specific laying dates and alternative behavioral strategies for protecting the clutch. This study provides new perspectives to investigate avian parental behaviour.

scholarly journals Is it safe to nest near bold neighbours? Spatial patterns in predation risk associated with the density of American Golden-Plover nest

2016 ◽  
Author(s):  
Marie-Andrée Giroux ◽  
Myriam Trottier-Paquet ◽  
Joël Bêty ◽  
Vincent Lamarre ◽  
Nicolas Lecomte
Keyword(s):  
Predation Risk ◽  
Spatial Patterns ◽  
Bird Species ◽  
Artificial Nests ◽  
Species Of Conservation Concern ◽  
Composition And Structure ◽  
Negative Effect ◽  
Conservation Concern ◽  
Golden Plover ◽  
Mobbing Behaviour

Predation is one of the main factors explaining nesting mortality in most bird species. Birds can avoid nest predation or reduce predation pressure by breeding at higher latitude, showing anti-predator behaviour, and nesting in association with protective species. Plovers actively defend their territory by displaying early warning and aggressive/mobbing behaviour, potentially benefiting the neighbouring nests by decreasing their predation risk. To test for the existence of such a protective effect, we studied the influence of proximity to plover nests on predation risk of artificial nests on Igloolik Island (Nunavut, Canada) in July 2014. We predicted that the predation risk of artificial nests increases and decreases with the distance to and the density of plover nests, respectively. We monitored 18 plover nests and set 35 artificial nests at 30, 50, 100, 200 and 500 m from seven of those plover nests. Surprisingly, we showed that predation risk of artificial nests increases with the density of active plover nests. We also found a significant negative effect of the distance to the nearest active protector nest on predation risk of artificial nests. Understanding how the composition and structure of shorebird communities generate spatial patterns in predation risks represent a key step to better understand the importance of these species of conservation concern in tundra food webs.

Dung longevity influences the fate of endozoochorically dispersed seeds in forest ecosystems

Botany ◽  
2011 ◽  
Vol 89 (11) ◽  
pp. 779-785 ◽  
Author(s):  
Bogdan Jaroszewicz ◽  
Ewa Pirożnikow
Keyword(s):  
Plant Species ◽  
Deciduous Forest ◽  
Coniferous Forest ◽  
Light Availability ◽  
European Bison ◽  
Plant Establishment ◽  
Seed Content ◽  
Closed Canopy ◽  
Seedling Germination ◽  
Forest Habitats

Many studies show large discrepancies between the potential (studied in the greenhouse) and realized (studied in the field) effects of endozoochory. The influence of environmental conditions on the fate of endozoochorically dispersed seeds and subsequent plant establishment is still not well understood. We addressed this issue by studying the viable seed content of the dung of European bison ( Bison bonasus L.) by means of seedling germination in the greenhouse and in two forest habitats in Białowieża Primeval Forest. The number of seedlings and the number of plant species that emerged from 1 L of feces were positively correlated with dung longevity. Generative shoots were produced by plants only in coniferous forest. Their number was positively correlated with dung longevity and with light availability. Germination of seeds from bison feces was higher in coniferous forest than in deciduous forest but did not differ between open- and closed-canopy plots within the same habitat. We conclude that (i) seed germination and plant establishment after endozoochorous dispersal is influenced by dung longevity; (ii) the number of generative shoots produced by endozoochorously dispersed plants is influenced by dung longevity and light availability; (iii) seeds of some plant species, present in dung, stay viable for at least 3 years.

scholarly journals Testing Whether Camera Presence Influences Habitat Specific Predation Pressure on Artificial Shorebird Nests in the Arctic

ARCTIC ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 22-29
Author(s):  
Kevin G. Young ◽  
Lisa V. Kennedy ◽  
Paul A. Smith ◽  
Erica Nol
Keyword(s):  
Predation Risk ◽  
Proportional Hazards Model ◽  
Habitat Type ◽  
Cox Proportional Hazards Model ◽  
The Arctic ◽  
Arctic Fox ◽  
Artificial Nests ◽  
Predator Species ◽  
Risk Of Predation ◽  
The Impact

When monitoring the breeding ecology of birds, the causes and times of nest failure can be difficult to determine. Cameras placed near nests allow for accurate monitoring of nest fate, but their presence may increase the risk of predation by attracting predators, leading to biased results. The relative influence of cameras on nest predation risk may also depend on habitat because predator numbers or behaviour can change in response to the availability or accessibility of nests. We evaluated the impact of camera presence on the predation rate of artificial nests placed within mesic tundra habitats used by Arctic-breeding shorebirds. We deployed 94 artificial nests, half with cameras and half without, during the shorebird-nesting season of 2015 in the East Bay Migratory Bird Sanctuary, Nunavut. Artificial nests were distributed evenly across sedge meadow and supratidal habitats typically used by nesting shorebirds. We used the Cox proportional hazards model to assess differential nest survival in relation to camera presence, habitat type, placement date, and all potential interactions. Artificial nests with cameras did not experience higher predation risk than those without cameras. Predation risk of artificial nests was related to an interaction between habitat type and placement date. Nests deployed in sedge meadows and in supratidal habitats later in the season were subject to a higher risk of predation than those deployed in supratidal habitats early in the season. These differences in predation risk are likely driven by the foraging behaviour of Arctic fox (Vulpes lagopus), a species that accounted for 81% of observed predation events in this study. Arctic fox prey primarily on Arvicoline prey and goose eggs at this site and take shorebird nests opportunistically, perhaps more often later in the season when their preferred prey becomes scarcer. This study demonstrates that, at this site, cameras used for nest monitoring do not influence predation risk. Evaluating the impact of cameras on predation risk is critical prior to their use, as individual study areas may differ in terms of predator species and behaviour.

scholarly journals Is it safe to nest near conspicuous neighbours? Spatial patterns in predation risk associated with the density of American Golden-Plover nests

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2193 ◽  
Author(s):  
Marie-Andrée Giroux ◽  
Myriam Trottier-Paquet ◽  
Joël Bêty ◽  
Vincent Lamarre ◽  
Nicolas Lecomte
Keyword(s):  
Predation Risk ◽  
Spatial Patterns ◽  
Bird Species ◽  
Antipredator Behaviour ◽  
Artificial Nests ◽  
Nest Sites ◽  
Species Of Conservation Concern ◽  
Composition And Structure ◽  
Negative Effect ◽  
Conservation Concern

Predation is one of the main factors explaining nesting mortality in most bird species. Birds can avoid nest predation or reduce predation pressure by breeding at higher latitude, showing anti-predator behaviour, selecting nest sites protected from predators, and nesting in association with protective species. American Golden-Plovers (Pluvialis dominica) defend their territory by using various warning and distraction behaviours displayed at varying levels of intensity (hereafter “conspicuous behaviour”), as well as more aggressive behaviours such as aerial attacks, but only in some populations. Such antipredator behaviour has the potential to repel predators and thus benefit the neighbouring nests by decreasing their predation risk. Yet, conspicuous behaviour could also attract predators by signalling the presence of a nest. To test for the existence of a protective effect associated with the conspicuous antipredator behaviour of American Golden-Plovers, we studied the influence of proximity to plover nests on predation risk of artificial nests on Igloolik Island (Nunavut, Canada) in July 2014. We predicted that the predation risk of artificial nests would decrease with proximity to and density of plover nests. We monitored 18 plover nests and set 35 artificial nests at 30, 50, 100, 200, and 500 m from seven of those plover nests. We found that the predation risk of artificial nests increases with the density of active plover nests. We also found a significant negative effect of the distance to the nearest active protector nest on predation risk of artificial nests. Understanding how the composition and structure of shorebird communities generate spatial patterns in predation risks represents a key step to better understand the importance of these species of conservation concern in tundra food webs.

Further studies on the chipmunk warble, Cuterebra emasculator (Diptera: Cuterebridae)

1972 ◽  
Vol 50 (6) ◽  
pp. 861-864 ◽  
Author(s):  
Gordon F. Bennett
Keyword(s):  
Parasite Density ◽  
Coniferous Forest ◽  
Coniferous Forests ◽  
Forest Habitat ◽  
Mixed Forests ◽  
Tamias Striatus ◽  
Age Class ◽  
Adult Females ◽  
Second Growth ◽  
Forest Habitats

The prevalence of Cuterebra emasculator Fitch in 1328 chipmunks (Tamias striatus) was analyzed as to the sex and age class of the host and to the forest habitats from which the chipmunks were obtained. The prevalence of the parasite was highest in immature animals of both sexes and lowest in adult females. Prevalence of C. emasculator was highest in chipmunks from second-growth mixed forests; such animals also carried more parasites per animal. Chipmunks from mature coniferous forests harbored the fewest parasites per individual and the prevalence was the lowest. The parasite density was extremely low, averaging one fly per 2.8 acres in mature coniferous forest and one fly per 0.7 acres in the second-growth forest habitat.

Stemflow and dissolved organic carbon cycling: temporal variability in concentration, flux, and UV-Vis spectral metrics in a temperate broadleaved deciduous forest in the eastern United States

2012 ◽  
Vol 42 (1) ◽  
pp. 207-216 ◽  
Author(s):  
Delphis F. Levia ◽  
John T. Van Stan, II ◽  
Shreeram P. Inamdar ◽  
Matthew T. Jarvis ◽  
Myron J. Mitchell ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Deciduous Forest ◽  
Fagus Grandifolia ◽  
Eastern United States ◽  
Storm Events ◽  
Yellow Poplar ◽  
American Beech ◽  
Order Of Magnitude ◽  
Chemical Character

No known research has examined the concentration and flux of dissolved organic carbon (DOC) for stemflow across temporal scales from within single storm events to seasonal and annual scales or employed UV-Vis spectral metrics to examine the chemical character of dissolved organic matter (DOM) of stemflow drainage. Thus, our study examined stemflow DOC concentration and flux and DOM character from American beech ( Fagus grandifolia Ehrh.) and yellow poplar ( Liriodendron tulipifera L.) to address this data gap. Intrastorm stemflow DOC concentrations and fluxes diminished by an order of magnitude over time for American beech but remained relatively constant for yellow poplar. Stemflow DOM aromaticity, however, generally increased and E2:E3 ratios generally decreased as events progressed, suggesting transport of different compounds at different moments. Although less enriched in DOC than yellow poplar, American beech stemflow DOC fluxes were double per annum. Differential interspecific stemflow DOM characteristics are ascribed to (i) significant differences in SUVA254 values (aromaticity) for the leafless season and annually and (ii) significantly higher E2:E3 and SR ratios for yellow poplar stemflow than for American beech annually and across leafed and leafless seasons. Our results suggest that stemflow significantly affects the amount and chemical character of carbon flux to the forest floor that may engender hot spots around tree boles.

Restored meadow harvestman communities (Opiliones) in the Bílé Karpaty Protected Landscape Area, Czech Republic

Biologia ◽  
2006 ◽  
Vol 61 (2) ◽  
Author(s):  
Slavomír Stašiov ◽  
Karel Tajovský ◽  
Květoslav Resl
Keyword(s):  
Crop Rotation ◽  
Natural Regeneration ◽  
Deciduous Forest ◽  
Plant Cover ◽  
Subsequent Development ◽  
Plant Succession ◽  
Pitfall Trapping ◽  
Successive Formation ◽  
Seed Mixture ◽  
Forest Habitats

AbstractHarvestman communities inhabiting plots treated differently for grassland restoration were investigated at the Výzkum site near Malá Vrbka village (Bílé Karpaty Protected Landscape Area). Harvestman were sampled by pitfall trapping from 1999 to 2003 on plots sown with native haymeadow seed mixture, also on plots where narrow strips of regional seed mixtures were sown either within a matrix of commercial grass mixture or within vegetation cover in natural regeneration state and on plots in a natural regeneration state. Additionally, harvestman were collected in a field under permanent crop rotation and in a neighbouring xerothermic deciduous forest. In total, 5,086 individuals of harvestman representing 15 species from three families were obtained. Phalangium opilio was dominant (78%) and P. opilio, Rilaena triangularis and Zachaeus crista were the most frequent species. The results confirmed colonisation and subsequent development of harvestman communities on meadows in various state of restoration, including plots with spontaneous plant succession. Nevertheless, biotope character and successive formation of plant cover evidently influenced the structure of harvestman communities. The highest number of taxa (12) was recorded on plots with natural regeneration; the lowest one (9) was recorded in the field with permanent crop rotation. The highest values of diversity and equitability indices of harvestman communities were found in neighbouring forest habitats representing possible sources of harvestman migration.

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%).

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