Landscape‐scale distribution of nest predators and its relationship with regent honeyeater nest success

Context Enclosing nests in cages to exclude predators is a management tool frequently used to increase the reproductive success of threatened ground-nesting precocial birds. This technique has seldom been used with passerines, despite the predicted increased benefit for altricial species due to their longer period of nest dependency. Aims The aims of this study were to determine (1) whether cages could be installed around the nests of a threatened, shrub-nesting passerine without causing parental desertion, and (2) whether caged nests could successfully exclude the dominant nest predators and increase nesting success. Methods Cages with four different mesh sizes (1000 mm, 200 mm, 100 mm, 50 mm) were installed sequentially in trials at four nests in a secure population and three nests in an endangered population of white-fronted chats (Epthianura albifrons) to investigate susceptibility to desertion. Trials using 160 caged and uncaged artificial nests were used to determine the efficacy of 50-mm wire mesh in preventing access to eggs by potential nest predators. Key results Parent birds accepted nest cages, which reduced predation rates on artificial nests from 96% to 14%. Infrared-triggered cameras revealed that corvids were responsible for 94% of predation episodes. Nest success of caged white-fronted chat nests was 85% (n = 7). Conclusions Nest cages do not appear to have negative effects on nest success of white-fronted chats, and may considerably increase reproductive success. Implications Nest cages may aid conservation of the endangered population of white-fronted chats and other endangered songbird species.

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LANDSCAPE-SCALE PATTERNS OF BLACK-THROATED SPARROW (AMPHISPIZA BILINEATA) ABUNDANCE AND NEST SUCCESS

Ecological Applications ◽

10.1890/1051-0761(2003)013[0530:lspobt]2.0.co;2 ◽

2003 ◽

Vol 13 (2) ◽

pp. 530-542 ◽

Cited By ~ 37

Author(s):

A. M. Pidgeon ◽

V. C. Radeloff ◽

N. E. Mathews

Keyword(s):

Nest Success ◽

Landscape Scale ◽

Amphispiza Bilineata

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Nest predators, nest-site selection and nest success of the Emei Shan Liocichla (Liocichla omeiensis), a vulnerable babbler endemic to southwestern China

Avian Research ◽

10.1186/s40657-016-0054-1 ◽

2016 ◽

Vol 7 (1) ◽

Cited By ~ 8

Author(s):

Yiqiang Fu ◽

Benping Chen ◽

Simon D. Dowell ◽

Zhengwang Zhang

Keyword(s):

Site Selection ◽

Nest Site ◽

Nest Success ◽

Nest Site Selection ◽

Southwestern China ◽

Liocichla Omeiensis ◽

Nest Predators

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Evaluating the ecological and behavioural factors influencing Snowy PloverCharadrius nivosusegg hatching and the potential benefits of predator exclosures

Bird Conservation International ◽

10.1017/s0959270914000331 ◽

2014 ◽

Vol 26 (1) ◽

pp. 100-118 ◽

Cited By ~ 3

Author(s):

SCOTT F. PEARSON ◽

SHANNON M. KNAPP ◽

CYNDIE SUNDSTROM

Keyword(s):

Spatial Scales ◽

Nest Success ◽

High Tide ◽

Quadratic Function ◽

Wire Mesh ◽

Habitat Characteristics ◽

Conservation Strategies ◽

Active Nest ◽

Factors Influencing ◽

Nest Predators

SummaryAn understanding of the ecological factors influencing nest success and the effectiveness of management activities focused on improving nest success can be critical to successful conservation strategies for rare or declining species. Over seven breeding seasons (2006–2012) we examined the influence of nest spacing and habitat characteristics on hatching success for the nationally threatened Pacific coast population of the Snowy PloverCharadrius nivosusin coastal Washington, USA in two study areas. Specifically, we assessed the influence of clutch age, nesting season date, distance to conspecific nests, perpendicular distance to the high-tide (wrack) line, vegetation cover and other habitat characteristics at three spatial scales (1m2, 5m2, and 25 m2) centred on the nest. We also assessed the effectiveness of wire mesh cages placed around nests to exclude mammalian and avian nest-predators. We discovered and monitored 307 nests, placed predator exclosures around 142 of these nests and measured habitat variables at 251. Our selected base model included site and quadratic function of season-date. For the analysis examining habitat effects on nest success, only models with distance to nearest active nest ranked higher than the baseline model even when removing the nests that were very distant from conspecific nests (outliers). For these unexclosed nests, predation was the primary source of nest failure and crows and ravens were apparently the primary nest predators. Predator exclosures had a clear positive influence on nest survival. Even though we observed a positive exclosure effect, we recommend that they be used cautiously because we and others have observed adult mortality associated with exclosures. Regardless of the spatial scale, Snowy Plovers are primarily using nest sites with little vegetation, shell or woody material cover suggesting the need for large expanses of very sparsely or unvegetated habitats that allow birds to nest semi-colonially (with near neighbours).

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Local- versus landscape-scale effects on the demography of three forest-breeding songbirds in Ontario, Canada

Canadian Journal of Zoology ◽

10.1139/z2012-051 ◽

2012 ◽

Vol 90 (7) ◽

pp. 815-828 ◽

Cited By ~ 9

Author(s):

S. Richmond ◽

E. Nol ◽

D. Burke

Keyword(s):

Spatial Scales ◽

Nest Success ◽

Landscape Scale ◽

Landscape Composition ◽

Multiscale Approach ◽

Forest Fragments ◽

Wood Thrush ◽

Complex Species ◽

American Robins ◽

Vegetation Characteristics

Reproductive success of songbirds breeding in forest fragments can be influenced by local habitat characteristics and by anthropogenic land uses in the surrounding matrix such as exurban development and agriculture. Effectively managing these songbirds requires an understanding of which spatial scales most strongly influence their demography. We conducted a multiscale study to investigate the relative influence of local vegetation characteristics and landscape composition at two spatial scales (100 and 2000 m) in a predominantly agricultural landscape on songbird demography. Density, pairing success, nest success, and productivity were assessed for Ovenbirds ( Seiurus aurocapilla (L., 1766)), Wood Thrush ( Hylocichla mustelina (J.F. Gmelin, 1789)), and American Robins ( Turdus migratorius L., 1766) in 16 deciduous forest fragments in southeastern Ontario. Demography of Ovenbirds was most strongly associated with local vegetation characteristics, while demography of Wood Thrush and American Robins was most strongly related to landscape composition within a 2000 m buffer. For all three species, cross-scale correlations influenced nest success, although other demographic parameters were less affected. We conclude that relationships between local- and landscape-scale metrics and songbird demography are complex, species-specific, and differ among reproductive parameters, necessitating a multiscale approach to management.

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Greater Sage-Grouse Nest Predators in the Virginia Mountains of Northwestern Nevada

Journal of Fish and Wildlife Management ◽

10.3996/122012-jfwm-110r1 ◽

2013 ◽

Vol 4 (2) ◽

pp. 242-255 ◽

Cited By ~ 19

Author(s):

Zachary B. Lockyer ◽

Peter S. Coates ◽

Michael L. Casazza ◽

Shawn Espinosa ◽

David J. Delehanty

Keyword(s):

Anthropogenic Activities ◽

Nest Success ◽

Nest Survival ◽

Lynx Rufus ◽

Central Component ◽

Sage Grouse ◽

Habitat Alterations ◽

Management Actions ◽

Northwestern Nevada ◽

Nest Predators

Abstract Greater sage-grouse Centrocercus urophasianus, hereafter sage-grouse, populations have declined across their range due to the loss, degradation, and fragmentation of habitat. Habitat alterations can lead not only to vegetative changes but also to shifts in animal behavior and predator composition that may influence population vital rates, such as nest success. For example, common ravens Corvus corax are sage-grouse nest predators, and common raven abundance is positively associated with human-caused habitat alterations. Because nest success is a central component to sage-grouse population persistence, research that identifies factors influencing nest success will better inform conservation efforts. We used videography to unequivocally identify sage-grouse nest predators within the Virginia Mountains of northwestern Nevada, USA, from 2009 to 2011 and used maximum likelihood to calculate daily probability of nest survival. In the Virginia Mountains, fires, energy exploration, and other anthropogenic activities have altered historic sage-grouse habitat. We monitored 71 sage-grouse nests during the study, placing video cameras at 39 nests. Cumulative nest survival for all nests was 22.4% (95% CI, 13.0–33.4%), a survival rate that was significantly lower than other published results for sage-grouse in the Great Basin. Depredation was the primary cause for nest failure in our study (82.5%), and common ravens were the most frequent sage-grouse nest predator, accounting for 46.7% of nest depredations. We also successfully documented a suite of mammalian and reptilian species depredating sage-grouse nests, including some predators never previously confirmed in the literature to be sage-grouse nest predators (i.e., bobcats Lynx rufus and long-tailed weasels Mephitis frenata). Within the high elevation, disturbed habitat of the Virginia Mountains, low sage-grouse nest success may be limiting sage-grouse population growth. These results suggest that management actions that restore habitat in the Virginia Mountains and decrease anthropogenic subsidies of ravens will benefit sage-grouse.

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