scholarly journals Nest-Site Selection Patterns and the Influence of Vegetation on Nest Survival of Mixed-Grass Prairie Passerines

The Condor ◽  
2005 ◽  
Vol 107 (3) ◽  
pp. 605-616 ◽  
Author(s):  
Stephen K. Davis

Abstract Identification of habitat features influencing reproduction and survival are essential for the management and long-term viability of grassland bird populations. I quantified vegetation structure at nests and random sites in southern Saskatchewan, Canada, to determine which microhabitat features are important in nest-site selection by Sprague's Pipit (Anthus spragueii), Savannah Sparrow (Passerculus sandwichensis), Baird's Sparrow (Ammodramus bairdii), Chestnut-collared Longspur (Calcarius ornatus), and Western Meadowlark (Sturnella neglecta). In addition, I related microhabitat features to nest survival to determine whether predation might influence their choice of nest sites. Grassland passerines exhibited nonrandom nest-placement patterns and built their nests in sites that were characterized by a greater density of dead vegetation within 30 cm of the ground, increased amounts of litter, and reduced coverage of bare ground. In addition, each species nested in taller vegetation than that found at random sites. However, nests were partitioned along a vegetation gradient ranging from relatively short and sparse (e.g., Chestnut-collared Longspur) to relatively tall and dense (e.g., Western Meadowlark). Nest survival varied with time-specific variables (nest age and date) and year, with nest-site vegetation explaining additional variation not accounted for by these effects. However, vegetation effects were highly variable compared to age effects. Diverse predator communities, spatial and temporal variation in selection pressures, and other constraints may account for inconsistent relationships between nest survival and nest-site characteristics for grassland passerines. Patrones de Selección de Sitios de Nidificación y la Influencia de la Vegetación en la Supervivencia de Nidos de Aves Paserinas de Praderas de Pastos Mixtos Resumen. La identificación de las características del ambiente que influencian la reproducción y la supervivencia son esenciales para el manejo y la viabilidad al largo plazo de las poblaciones de las aves de pastizal. Cuantifiqué la estructura de la vegetación alrededor de los nidos y en sitios aleatorios en el sur de Saskatchewan, Canadá, para determinar cuáles rasgos micro-ambientales son importantes en la selección de nidos por parte de Anthus spragueii, Passerculus sandwichensis, Ammodramus bairdii, Calcarius ornatus y Sturnella neglecta. Adicionalmente, relacioné los rasgos micro-ambientales con la supervivencia de los nidos para determinar si la depredación podría influir sobre la elección de los sitios de nidificación. Las aves paserinas de pastizal mostraron patrones no aleatorios de ubicación de los nidos y construyeron sus nidos en sitios que se caracterizaron por una densidad más alta de vegetación muerta en los primeros 30 cm desde el suelo, una mayor cantidad de hojarasca y una baja cobertura de suelo desnudo. Adicionalmente, cada especie nidificó en sitios con vegetación más alta que la de los sitios elegidos al azar. Sin embargo, los nidos se distribuyeron a lo largo de un gradiente de vegetación desde relativamente corta y esparcida (e.g., Calcarius ornatus) a relativamente alta y densa (e.g., Sturnella neglecta). La supervivencia de los nidos varió en relación con variables que dependen del tiempo (edad del nido y fecha) y del año, mientras que la vegetación de los sitios donde se ubicaron los nidos explicó una parte adicional de la variación no explicada por estos factores. Sin embargo, los efectos de la vegetación fueron muy variables comparados de modo general con los efectos de la edad. Las diferencias en las comunidades de depredadores, la variación espacial y temporal en las presiones de selección y otras limitantes podrían explicar las relaciones inconsistentes entre la supervivencia de los nidos y las características de los sitios de nidificación para las aves paserinas de pastizal.

The Condor ◽  
2021 ◽  
Vol 123 (1) ◽  
Author(s):  
Christopher R Anthony ◽  
Christian A Hagen ◽  
Katie M Dugger ◽  
R Dwayne Elmore

Abstract Temperature at fine spatial scales is an important driver of nest site selection for many avian species during the breeding season and can influence nest success. Sagebrush (Artemisia spp.) communities have areas with high levels of vegetation heterogeneity and high thermal variation; however, fire removes vegetation that provides protection from predators and extreme environmental conditions. To examine the influence of microclimates on Greater Sage-Grouse (Centrocercus urophasianus) nest site selection and nest success in a fire-affected landscape, we measured black bulb temperature (Tbb) and vegetation attributes (e.g., visual obstruction) at 3 spatial scales (i.e. nest bowl, microsite, and landscape) in unburned and burned areas. Nest bowls exhibited greater buffering of Tbb than both nearby microsites and the broader landscape. Notably, nest bowls were warmer in cold temperatures, and cooler in hot temperatures, than nearby microsites and the broader landscape, regardless of burn stage. Nest survival (NS) was higher for nests in unburned areas compared to nests in burned areas (unburned NS = 0.43, 95% confidence interval [CI]: 0.33–0.54; burned NS = 0.24, 95% CI: 0.10–0.46). The amount of bare ground was negatively associated with NS, but effects diminished as the amount of bare ground reached low levels. Shrub height and visual obstruction were positively associated with NS during the entire study period, whereas minimum Tbb had a weaker effect. Our findings demonstrate that thermoregulatory selection by Greater Sage-Grouse at nest sites had marginal effects on their NS. However, given that increases in vegetation structure (e.g., shrub height) provide thermal refuge and increase NS, vegetation remnants or regeneration in a post-fire landscape could be critical to Greater Sage-Grouse nesting ecology.


The Condor ◽  
2019 ◽  
Vol 121 (3) ◽  
Author(s):  
Adrian P Monroe ◽  
L Wes Burger ◽  
James A Martin

Abstract Exotic grasses such as bermudagrass (Cynodon dactylon) and tall fescue (Schedonorus arundinaceus) are widely established across the southeastern United States as livestock forage, but their structure and management can limit avian reproductive success. Native warm-season grasses (NWSG) are promoted as sustainable forage alternatives. To examine nesting suitability for tall structure specialists such as Dickcissels (Spiza americana) we established an operational-scale study in northeastern Mississippi, USA, with 4 treatments along a gradient of beef production intensity. Treatments included grazed exotic forages, 2 grazed NWSG treatments including Indiangrass (Sorghastrum nutans) monoculture and NWSG polyculture of Indiangrass, little bluestem (Schizachyrium scoparium), and big bluestem (Andropogon gerardii), and an ungrazed NWSG polyculture treatment. We monitored 208 Dickcissel nests in 2011 and 2012 to evaluate effects of treatment, vegetation structure, fire ants (Solenopsis spp.), and arthropod prey biomass on nest-site selection and nest survival. Survival rates varied among treatments and increased with pasture-scale visual obstruction reading (VOR), being lowest among grazed exotic grass, intermediate in grazed NWSG, and highest in ungrazed NWSG. Although Dickcissels selected nest sites with greater VOR, we found little support for effects of nest-site vegetation on survival. However, nest survival was lower for nests in shrubs that also occurred in pastures with greater shrub cover, and selection for shrubs declined as pasture-scale VOR increased, suggesting a functional response in selection. We found little support for food availability influencing nest survival. These results suggest NWSG pastures increase Dickcissel nest success through greater pasture-scale VOR by reducing Dickcissel selection of shrubs for nest sites, and possibly by reducing predator efficiency. Incorporating NWSG into beef production systems while maintaining availability of tall vegetation could benefit Dickcissels and other tall structure specialists.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9892
Author(s):  
Rocío Fernanda Jara ◽  
Ramiro Daniel Crego ◽  
Michael David Samuel ◽  
Ricardo Rozzi ◽  
Jaime Enrique Jiménez

Background Birds can maximize their reproductive success through careful selection of nest-sites. The ‘total-foliage’ hypothesis predicts that nests concealed in vegetation should have higher survival. We propose an additional hypothesis, the ‘predator proximity’ hypothesis, which states that nests placed farther from predators would have higher survival. We examined these hypotheses in the world’s southernmost forests of Navarino Island, in the Cape Horn Biosphere reserve, Chile (55°S). This island has been free of mammalian ground predators until recently, and forest passerines have been subject to depredation only by diurnal and nocturnal raptors. Methods During three breeding seasons (2014–2017), we monitored 104 nests for the five most abundant open-cup forest-dwelling passerines (Elaenia albiceps, Zonotrichia capensis, Phrygilus patagonicus, Turdus falcklandii, and Anairetes parulus). We identified nest predators using camera traps and assessed whether habitat characteristics affected nest-site selection and survival. Results Nest predation was the main cause of nest failure (71% of failed nests). Milvago chimango was the most common predator, depredating 13 (87%) of the 15 nests where we could identify a predator. By contrast, the recently introduced mammal Neovison vison, the only ground predator, depredated one nest (7%). Species selected nest-sites with more understory cover and taller understory, which according to the total-foliage hypothesis would provide more concealment against both avian and mammal predators. However, these variables negatively influenced nest survival. The apparent disconnect between selecting nest-sites to avoid predation and the actual risk of predation could be due to recent changes in the predator assemblage driven by an increased abundance of native M. chimango associated with urban development, and/or the introduction of exotic mammalian ground predators to this island. These predator assemblage changes could have resulted in an ecological trap. Further research will be needed to assess hypotheses that could explain this mismatch between nest-site selection and nest survival.


2020 ◽  
Vol 84 (3) ◽  
pp. 542-552
Author(s):  
Casey M. Setash ◽  
William L. Kendall ◽  
David Olson

2017 ◽  
Vol 81 (6) ◽  
pp. 1073-1083 ◽  
Author(s):  
Nathan A. Yeldell ◽  
Bradley S. Cohen ◽  
Andrew R. Little ◽  
Bret A. Collier ◽  
Michael J. Chamberlain

2013 ◽  
Vol 125 (3) ◽  
pp. 570-582 ◽  
Author(s):  
Nicholas M. Anich ◽  
Mike Worland ◽  
Karl J. Martin

The Condor ◽  
2019 ◽  
Vol 121 (3) ◽  
Author(s):  
Andrew N Stillman ◽  
Rodney B Siegel ◽  
Robert L Wilkerson ◽  
Matthew Johnson ◽  
Christine A Howell ◽  
...  

Abstract Recently burned coniferous forests host wildlife communities that respond to variation in burn severity, post-fire habitat structure, and patch configuration. Habitat selection theory predicts that birds inhabiting these variable post-fire landscapes will select nesting locations that confer an adaptive advantage through increased fitness and reproductive success. Understanding the effect of post-fire habitat on avian nesting ecology can provide valuable information to guide restoration and management after wildfire. The Black-backed Woodpecker (Picoides arcticus) is strongly associated with recently burned forests in the western United States, where it is used as an indicator species for the effects of post-fire forest management. Between 2011 and 2018, we located and monitored 118 Black-backed Woodpecker nests in burned forests of northern California. We evaluated the influence of habitat and nest characteristics on nest site selection and daily nest survival. Our results demonstrate a pattern of neutral congruence between habitat selection and fitness. Black-backed Woodpeckers showed strong selection for each of the nest habitat variables that we measured: woodpeckers selected moderately sized trees in areas of high snag density burned at high severity, but also in areas relatively close to low-severity or unburned edges. However, only nest initiation date affected nest survival, with decreased survival in late-season nests. Our results suggest that management actions aimed at maintaining breeding habitat for Black-backed Woodpeckers should prioritize retention and creation of pyrodiverse landscapes that include dense stands of snags (>5 snags per 100 m2) within ~500 m of forest that burned at low severity or remained unburned.


2008 ◽  
Vol 35 (1) ◽  
pp. 65 ◽  
Author(s):  
Stuart J. N. Cooney ◽  
David M. Watson

Recent research has documented an unprecedented diversity of birds using mistletoes as nest-sites, and a strong preference for nesting in mistletoes has recently been demonstrated for some species. The consequences and underlying reasons for this behaviour have not been evaluated, and it is unclear whether nests in mistletoes confer advantages compared with other available substrates. Nest predation is often cited as the most important factor regulating many bird populations and is thought to influence all aspects of nest-site selection. To evaluate whether nest predation may play a role in the widespread use of mistletoe as a nest-site, we conducted an artificial nest predation experiment in a eucalypt woodland in southern New South Wales, Australia. Artificial nests were modelled on noisy friarbird (Philemon corniculatus: Meliphagidae) nests, baited with a single quail egg and checked after four days. We used logistic regression to model the rate of depredation between plant substrates, and demonstrate that, in this experiment, mistletoe nests experienced a lower proportion of predation than eucalypt nests (51.5% versus 63.8% respectively). This finding suggests that predation may influence the widespread use of mistletoe as a nest-site in a range of habitats and regions. In addition to clarifying priorities for further work on mistletoe nesting, this finding has implications for studies of nest-site selection generally, with researchers encouraged to supplement between-substrate comparisons with direct measurements of within-substrate variation.


2007 ◽  
Vol 119 (3) ◽  
pp. 392-399 ◽  
Author(s):  
MICHAEL J. RADER ◽  
LEONARD A. BRENNAN ◽  
FIDEL HERNÁNDEZ ◽  
NOVA J. SILVY ◽  
BEN WU

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