Resolving the urban nest predator paradox: The role of alternative foods for nest predators

2011 ◽  
Vol 144 (5) ◽  
pp. 1545-1552 ◽  
Author(s):  
Christine M. Stracey
Keyword(s):  
Nest Predator ◽  
Nest Predators

Response to logging by a limited but variable nest predator guild in the boreal forest

2008 ◽  
Vol 38 (7) ◽  
pp. 1974-1982 ◽  
Author(s):  
Randy G. Thompson ◽  
Ian G. Warkentin ◽  
Stephen P. Flemming
Keyword(s):  
Boreal Forest ◽  
Nest Predation ◽  
Forest Cover ◽  
Landscape Fragmentation ◽  
Artificial Nests ◽  
Gray Jays ◽  
Predator Guild ◽  
Nest Predator ◽  
Predation Rates ◽  
Nest Predators

Predation rates on the eggs and young of forest-nesting songbirds typically rise in association with anthropogenic fragmentation, but predator responses depend on the spatial scale of disturbance, context, and predator assemblages present. For landscapes that are naturally fragmented, such as the boreal forest, our understanding of nest predation patterns associated with harvest may be further confounded by an additive response of nest predators to the loss of forest cover and the extension of habitat edges. We examined predation rates on artificial nests across a range of values for landscape metrics reflecting natural and anthropogenic forest fragmentation during two summers in boreal forest stands of western Newfoundland, Canada. Nest predation by gray jays ( Perisoreus canadensis (L.)) increased significantly in logged areas, and gray jay abundance was positively linked to increasing amounts of logged edge; however, there was no response to the extent of natural openings suggesting that nest predation by jays was additive in the presence of harvest-created openings. In contrast, neither mammalian nest predators nor the unidentified predators (responsible for the largest proportion of nest losses) showed any association with the landscape fragmentation metrics assessed. Year effects shown by the unidentified nest predator category did coincide with a marked increase in small mammal and Newfoundland marten ( Martes americana (Turton) subsp. atrata (Bangs)) populations during our study. Thus, we were able to identify an additive predation response to logging, but also that the activities of predators may vary over space and time and, in turn, may variably influence the success of songbirds nesting in forests fragmented by logging.

scholarly journals Plastering mud around the entrance hole affects the estimation of threat levels from nest predators in Eurasian Nuthatches

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiangping Yu ◽  
Li Zhang ◽  
Guodong Yi ◽  
Keqin Zhang ◽  
Jiyuan Yao ◽  
...  
Keyword(s):  
Nest Defence ◽  
Hole Size ◽  
Red Squirrels ◽  
Cavity Nesting ◽  
Sitta Europaea ◽  
Entrance Hole ◽  
Tamias Sibiricus ◽  
Threat Levels ◽  
Nest Predator ◽  
Nest Predators

Abstract Background For cavity-nesting birds, the nest entrance plays an important role in preventing predators from accessing nests. Several species of nuthatches use mud to narrow the entrance of cavities. In theory, the smaller the entrance hole size, the more effective it is against predators; however, few studies have tested whether narrowing the entrance hole size can affect the estimation of threat levels from nest predators in cavity-nesting birds. Methods Using dummy experiments, we tested whether Eurasian Nuthatches (Sitta europaea, narrow the entrance hole of cavities) and Cinereous Tits (Parus cinereus, do not narrow the entrance hole, as a control) perform different nest defence behaviours against Common Chipmunks (Tamias sibiricus, small nest predator) and Red Squirrels (Sciurus vulgaris, larger nest predator). Results Both nuthatches and tits exhibited stronger response behaviours (high dummy response scores) against chipmunks than against squirrels. Compared with tits, nuthatches exhibited more aggressive behaviours to chipmunks, but their responses to squirrels were similar. Conclusions Nest defence behaviours of nuthatches to chipmunks differed from tits, and the results suggested that nuthatches might estimate threat levels of nest predators according to their narrowed entrance-hole size.

scholarly journals Nesting Success and Nest Predators in Forest Fragments: A Study Using Real and Artificial Nests

The Auk ◽  
2000 ◽  
Vol 117 (2) ◽  
pp. 445-454 ◽  
Author(s):  
Liana Zanette ◽  
Bert Jenkins
Keyword(s):  
Nest Predation ◽  
Agricultural Land ◽  
Fragment Size ◽  
Nesting Success ◽  
Forest Fragments ◽  
Artificial Nests ◽  
Area Sensitivity ◽  
Avian Nest ◽  
Nest Predator ◽  
Nest Predators

Abstract Area sensitivity in songbirds is commonly attributed to increased nest predation in forest fragments. In 1995 and 1996, we tested whether the nest predators and nesting success of an area-sensitive forest bird, the Eastern Yellow Robin (Eopsaltria australis), varied with fragment size, and we also conducted an artificial nest experiment. The study occurred in two small (55 ha) and two large (>400 ha) forest fragments in a matrix of agricultural land in New South Wales, Australia. Predation accounted for 95% of all failures of 282 robin nests, and the survival of robin nests was negatively correlated with how frequently we observed avian nest predators near nests (i.e. nest-predator activity). Of 461 artificial nests, 84% were depredated, nearly all (99%) by birds. Thus, birds were important predators of nests. The abundance, species richness, and activity of avian nest predators were not related to fragment size. Survival of robin nests averaged 19%; nests in small fragments had a 22% chance of producing at least one fledgling compared with 15% in large fragments, but the difference was not significant. Survival of artificial nests averaged 12% in both small and large fragments. Nest-predator activity accounted for the most variation (68%) in the fate of robin nests, followed by the cumulative density of open-cup nesters (16%). The placement of robin nests had no influence on nest fate. We conclude that nest predation was not area dependent and propose food supply as an alternative hypothesis to explain area sensitivity. We suggest that, rather than being related to fragment size, nest predation increases with decreasing forest cover in a landscape. Increased nest predation in fragmented compared with contiguous landscapes may lower the population viability of songbirds in a region, and hence regional numbers. Therefore, the spatial scale at which fragmentation influences nest predation and songbird populations must be considered carefully.

Does the intrusion of an avian nest predator elicit a change in the behaviour of a canopy-nesting passerine?

Behaviour ◽  
2021 ◽  
pp. 1-26
Author(s):  
Alexander R. Sharp ◽  
Kamal Islam
Keyword(s):  
Nest Defence ◽  
Cyanocitta Cristata ◽  
Potential Predator ◽  
Reduce Activity ◽  
Provisioning Rate ◽  
Avian Nest ◽  
Cerulean Warblers ◽  
Stage 1 ◽  
Nest Predator ◽  
Nest Predators

Abstract Many studies have shown that nest predators affect their prey indirectly by inducing changes in the behaviour of the prey. Studies suggest that the type and degree of nest defence strategies depends heavily on species, along with nest type and location. One such strategy, nest vigilance, allows individuals to collect information and make informed decisions based on their surroundings. In this study, we simulated the intrusion of a common avian nest predator (blue jay, Cyanocitta cristata) into the territory of nesting cerulean warblers (Setophaga cerulea) and evaluated eight different behavioural variables to determine their response to the nest predator. Female cerulean warblers were more vigilant on their nest when exposed to a potential predator compared to a nest with lower threat of predation. Females exposed to a nest predator increased incubation bout by 109% and brooding bout by 60%. Our data also suggest that male cerulean warblers reduce their provisioning rate during the early nestling stage (−1 feeding/hour) and late nestling stage (−3 feedings/hour), although more data are needed. Modification of incubation bout length and nestling provisioning rate are common strategies employed by songbirds to reduce activity around the nest, by decreasing detection opportunities of visually-oriented nest predators. Currently, the only understanding we have on how cerulean warblers respond to a nest predator is based on observational data. The results of this study provide the first evidence that cerulean warblers are able to identify species that pose a threat to the safety of their nest, and that they modify their behaviour to reduce nest detection by predators. The results of this study provide a better understanding of a relatively unknown aspect of the breeding behaviour of this species. This study is also first to describe how an open-cup, canopy-nesting species responds to an increase in nest predation threat.

scholarly journals The role of fragmentation and landscape changes in the ecological release of common nest predators in the Neotropics

PeerJ ◽  
2014 ◽  
Vol 2 ◽  
pp. e464 ◽  
Author(s):  
Michael V. Cove ◽  
R. Manuel Spínola ◽  
Victoria L. Jackson ◽  
Joel C. Saénz
Keyword(s):  
Landscape Changes ◽  
Ecological Release ◽  
Nest Predators

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

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