Do Female Songbirds Avoid a Mammalian Nest Predator When Selecting Their Nest Site?

Perceived predation risk can elicit strong behavioral responses in potential prey. During nest building, songbirds exhibit anti-predator behaviors under experimental conditions. Here, we hypothesized that females of two ground-nesting songbird species, the Ovenbird (Seiurus aurocapilla) and the Hermit Thrush (Catharus guttatus), would use naturally available cues of predation risk when selecting their nest site, thereby avoiding activity hotspots of Eastern Chipmunks (Tamias striatus), a predator on songbird nests and fledglings. Chipmunks are highly vocal, thus providing cues of their presence. We mapped chipmunk detections and songbird nests over four successive years in study plots located in mature deciduous forest of New Brunswick, Canada. Chipmunk activity varied by an order of magnitude among study plots and years. Nests were built further away from chipmunk detections than expected by chance in some, but not all, plot-year combinations. When comparing study plots, the proportion of nests built within hotspots of chipmunk activity was four times lower in the two plots where chipmunk activity was highest. Yet, we did not find clear evidence that chipmunk avoidance provided fitness benefits, possibly because this behavior procured little protection at high chipmunk densities. The persistence of this avoidance behavior in our focal species of ground-nesting songbirds might be linked to the benefits it procures at intermediate chipmunk densities.

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Hermit Thrush (Catharus guttatus)

10.2173/bna.herthr.02 ◽

2012 ◽

Cited By ~ 1

Author(s):

Rachel Dellinger ◽

Petra Bohall Wood ◽

Peter W. Jones ◽

Therese M. Donovan

Keyword(s):

Catharus Guttatus ◽

Hermit Thrush

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Territory and Nest-Site Selection of Cerulean Warblers in Eastern Ontario

The Auk ◽

10.1093/auk/118.3.727 ◽

2001 ◽

Vol 118 (3) ◽

pp. 727-735 ◽

Cited By ~ 10

Author(s):

Jason Jones ◽

Raleigh J. Robertson

Keyword(s):

Site Selection ◽

Nest Site ◽

Deciduous Forest ◽

Spatial Scales ◽

Nest Site Selection ◽

Population Characteristics ◽

Dendroica Cerulea ◽

Large Trees ◽

Eastern Ontario ◽

Cerulean Warblers

Abstract We examined habitat selection by breeding Cerulean Warblers (Dendroica cerulea) at three spatial scales in eastern Ontario over three years (1997–1999). Territories were characterized by well-spaced large trees, with high canopies and dense foliage cover at heights between 12–18 m. Nesting habitat additionally was characterized by dense foliage cover above 18 m. The results of our nest-patch (0.04 ha circle around nest) and nest-site (0.01 ha circle) analyses indicate that male Cerulean Warblers may take active roles in nest-site selection when selecting territories. We conclude from our nest-patch and nest-site selection analyses that territories likely contain multiple nest patches and sites and that male Cerulean Warblers may defend areas with multiple nest patches or sites, which may attract females to settle with them. Whether or not Cerulean Warbler females use nest-site availability as a mate- or territory-choice cue remains unknown. We also tested the validity of a commonly made assumption that a random sampling of habitat by researchers is representative of the habitat actually available to birds and found that, in our study area, the assumption was invalid. Taken together, our results point toward the need to maintain sizeable stands of mature, deciduous forest to ensure the persistence of Cerulean Warblers in eastern Ontario. Population characteristics such as lower minimum area requirements and a resilience to habitat disturbance may make that an easier job in eastern Ontario than elsewhere in this species' breeding range.

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Benthic microalgae community response to flooding in a tropical salt flat

Brazilian Journal of Biology ◽

10.1590/1519-6984.18314 ◽

2016 ◽

Vol 76 (3) ◽

pp. 577-582 ◽

Cited By ~ 1

Author(s):

L. S. M. Masuda ◽

A. Enrich-Prast

Keyword(s):

Sea Water ◽

Shannon Index ◽

Community Response ◽

Microbial Mat ◽

Total Density ◽

Experimental Conditions ◽

Effect Of Water ◽

Salt Flat ◽

Field Samples ◽

Order Of Magnitude

Abstract This research evaluated the effect of flooding on the microphytobenthos community structure in a microbial mat from a tropical salt flat. Field samples were collected during four consecutive days: on the first three days the salt flat was dry, on the fourth day it was flooded by rain. In order to evaluate the community maintained in flood conditions, samples from this area were collected and kept in the laboratory for 10 days with sea water. The results of total abundance of microphytobenthos varied from 4.2 × 108 to 2.9 × 109 organisms L–1, total density increased one order of magnitude under the effect of water for both situations of precipitation in the salt flat and in experimental conditions, an increase due to the high abundance of Microcoleus spp. Shannon index (H’) was higher during the desiccation period. Our data suggest that changes in the abundance of organisms were due to the effect of water. The dominance of the most abundant taxa remained the same under conditions of desiccation and influence of water, and there is probably a consortium of microorganisms in the microbial mat that helps to maintain these dominances.

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Interspecific information on predation risk affects nest site choice in a passerine bird

BMC Evolutionary Biology ◽

10.1186/s12862-018-1301-3 ◽

2018 ◽

Vol 18 (1) ◽

Cited By ~ 4

Author(s):

Jere Tolvanen ◽

Janne-Tuomas Seppänen ◽

Mikko Mönkkönen ◽

Robert L. Thomson ◽

Hannu Ylönen ◽

...

Keyword(s):

Predation Risk ◽

Nest Site ◽

Passerine Bird ◽

Nest Site Choice

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

Canadian Journal of Zoology ◽

10.1139/z2012-035 ◽

2012 ◽

Vol 90 (6) ◽

pp. 694-703 ◽

Cited By ~ 14

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.

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Influence of prey diet quality on predator-induced traits in wood frog tadpoles (Lithobates sylvaticus)

Amphibia-Reptilia ◽

10.1163/15685381-bja10059 ◽

2021 ◽

pp. 1-11

Author(s):

Catherine Chuirazzi ◽

Melissa Ocampo ◽

Mizuki K. Takahashi

Keyword(s):

Predation Risk ◽

Diet Quality ◽

Growth And Development ◽

Chemical Cues ◽

Wood Frog ◽

Experimental Conditions ◽

Lithobates Sylvaticus ◽

Phenotypic Changes ◽

Intestinal Length ◽

Frog Tadpoles

Abstract Diet quality and predation are two critical factors in determining the growth and development of organisms. Various anurans are susceptible to phenotypic changes influenced by these factors. Yet, few studies examined prey diet quality as potential influence over predator-induced traits. Using wood frog tadpoles (Lithobates sylvaticus) as a model species, we investigated the effects of three diet compositions (plant-based, animal-based, omnivorous) crossed with presence or absence of chemical cues from predatory dragonfly larvae (Aeshnidae). After 35 days, we recorded 11 morphological measurements, Gosner stage, and intestinal length of tadpoles to assess phenotypic changes under the six different experimental conditions. Our results showed the additive effects of both diet quality and predator chemical cue without detection of interactions between the two. Tadpoles receiving the omnivorous diet grew and developed faster with wider denticle rows than those receiving the plant or animal diets. The growth and development of tadpoles receiving only the animal diet were significantly hindered. These results emphasize the importance of diet quality in the growth and development of larval wood frogs. Chemical cues from predators significantly reduced tadpole body size but, in contrast to previous findings, did not affect tail size. Our experimental procedure of providing water containing predator and injured conspecific chemical cues on a weekly basis likely provided relatively weak predation risk perceived by tadpoles compared to previous studies using caged predators. The predator environment in our experiment, however, represents one ecologically relevant scenario in which predation risk is not urgent.

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Interaction between atomic hydrogen and YBa2Cu3O7

Journal of Materials Research ◽

10.1557/jmr.1992.2908 ◽

1992 ◽

Vol 7 (11) ◽

pp. 2908-2915 ◽

Cited By ~ 1

Author(s):

Angel L.G. Ponce ◽

Jose J. Fripiat

Keyword(s):

Induction Period ◽

Atomic Hydrogen ◽

Dissociative Chemisorption ◽

Experimental Conditions ◽

Reaction Proceeds ◽

Order Of Magnitude ◽

O Vacancy ◽

The Creation ◽

Approximate Limit

Atomic hydrogen obtained from dissociative chemisorption of molecular H2 on Pt particles deposited on the surface of YBa2Cu3O7 reacts with the oxide in producing O vacancies and intercalating H at 82 °C under a H2 pressure of about 400 Torr. An induction period which extends over 1 h is observed as long as the concentration in O vacancies is below 0.1. Above this approximate limit the reaction proceeds quickly until about 1 mol H2 has been consumed. It then slows down progressively, but it is not completed even after 27 h of reaction and ∼1.4 H2 consumed, under these experimental conditions. The enthalpy for the creation of the O vacancy is 143 kcal/g mol O, while the H intercalation enthalpy is −57.5 kcal/g mol H. It appears that the reaction of molecular H2 over YBa2Cu3O7 not coated with Pt proceeds similarly, but the rate is nearly one order of magnitude slower, under identical conditions. The stoichiometry of the reaction agrees with the earlier suggestion that O1 is a labile oxygen which can be replaced by intercalated H. This site and the interstitial vacant sites in the copper chains square plane would be the first ones to be occupied by intercalated H.

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