Social information trumps vegetation structure in breeding-site selection by a migrant songbird

The fitness of female Pacific salmon (Oncorhynchus spp.) with respect to breeding behavior can be partitioned into at least four fitness components: survival to reproduction, competition for breeding sites, success of egg incubation, and suitability of the local environment near breeding sites for early rearing of juveniles. We evaluated the relative influences of habitat features linked to these fitness components with respect to selection of breeding sites by coho salmon (Oncorhynchus kisutch). We also evaluated associations between breeding site selection and additions of large wood, as the latter were introduced into the study system as a means of restoring habitat conditions to benefit coho salmon. We used a model selection approach to organize specific habitat features into groupings reflecting fitness components and influences of large wood. Results of this work suggest that female coho salmon likely select breeding sites based on a wide range of habitat features linked to all four hypothesized fitness components. More specifically, model parameter estimates indicated that breeding site selection was most strongly influenced by proximity to pool-tail crests and deeper water (mean and maximum depths). Linkages between large wood and breeding site selection were less clear. Overall, our findings suggest that breeding site selection by coho salmon is influenced by a suite of fitness components in addition to the egg incubation environment, which has been the emphasis of much work in the past.

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Should I stay or should I go? Indirect effects of livestock on bird nest-site selection in arid environments

The Rangeland Journal ◽

10.1071/rj18067 ◽

2019 ◽

Vol 41 (2) ◽

pp. 147 ◽

Cited By ~ 1

Author(s):

Mariana Tadey

Keyword(s):

Site Selection ◽

Vegetation Structure ◽

Nest Site ◽

Bird Species ◽

Nest Site Selection ◽

Raw Material ◽

Arid Environments ◽

Nesting Sites ◽

Selection Of ◽

Nest Abundance

Introduced livestock may indirectly affect bird species by decreasing vegetation structure and affecting the selection of nesting sites. This is especially true for birds that use shrubs as the raw material for nest construction or for nest placement. Nesting in inadequate supporting structures or the use of inadequate raw material for nest building may increase nest vulnerability (e.g. increasing structure weakness, falling and nest exposure to predation). Accordingly, bird species show a great variation in the selectivity of nesting sites and the raw material they use. Furnariidae family members exhibit an extraordinary diversity in nest placement and structure, which allows them to survive in different arid environments. I report here on a study of nest site selection of two common furnariid species, Leptasthenura aegithaloides and Pseudoseisura gutturalis, across a grazing gradient composed by nine independent paddocks within the same arid habitat. These species use large closed-nests (>40 cm long) built with thorny branches, placed on spiny shrubs. I measured nest abundance and supporting plants characteristics, vegetation structure, browsing intensity and compared the plants selected by the birds with the surrounding vegetation. These bird species used only few plant species for nest building and location. Livestock significantly reduced vegetation cover of the species used to build and place the nests, affecting nest site selection and reducing nest abundance. As livestock density increased, both species selected aggregated plants and the tallest plants for nesting, which may increase nest exposure. Therefore, livestock may indirectly affect nest-site selection of birds ultimately affecting their nesting ecology. This work illustrates how domestic livestock, through decreasing plant cover, may affect native biota with consequences on key species within an ecosystem.

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Marbled salamanders (Ambystoma opacum) choose low elevation nest sites when cover availability is controlled

Amphibia-Reptilia ◽

10.1163/156853806778190123 ◽

2006 ◽

Vol 27 (3) ◽

pp. 359-364 ◽

Cited By ~ 3

Author(s):

David Scott ◽

Dean Croshaw

Keyword(s):

Reproductive Success ◽

Reproductive Behavior ◽

Site Selection ◽

Nest Site ◽

Local Environment ◽

Breeding Site ◽

Nest Site Selection ◽

Growth And Survival ◽

Nest Sites ◽

Selective Forces

AbstractNest site selection is an important part of adult reproductive behavior because growth and survival of young are often affected by the local environment. In terrestrially nesting marbled salamanders, nest elevation is likely important to reproductive success because it is directly related to the time of hatching. We tested the hypothesis that females choose nest sites based on elevation and its correlates by controlling the availability of nesting cover, a potentially important factor in nest site selection which often covaries with elevation. Breeding adults were confined to field enclosures in which natural nesting cover had been removed and replaced with equal proportions of artificial cover in each of three elevation zones. In four enclosures that spanned from lowest to highest areas of a wetland breeding site, females used artificial nesting cover most frequently at low elevations. These results contrast with other studies in which intermediate elevations had highest nest densities, but are consistent with a conceptual model in which opposing selective forces result in locally adapted nest site selection.

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