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.

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.

Avian nest predation in Australian temperate forest and woodland: a review

2018 ◽  
Vol 24 (2) ◽  
pp. 122 ◽  
Author(s):  
Graham R. Fulton
Keyword(s):  
Nest Predation ◽  
Life Histories ◽  
Size Structure ◽  
Fragment Size ◽  
Conservation Strategy ◽  
Net Benefit ◽  
Phylogenetic Groups ◽  
Artificial Nests ◽  
The Impact ◽  
Nest Predators

Many forest and woodland birds are threatened by landscape modifications and predation, particularly nest predation. Nest predation affects a critical stage in avian life histories, which impacts the recruitment of new generations of adult birds. This review discusses the main issues in nest predation research in Australia: mesopredators, the use of artificial nests, ‘edge-effects’, the identification and role of nest predators and the responses of their prey. One conservation strategy is to selectively remove introduced mesopredators, but mesopredators iteratively replace one another, so the net benefit may be negligible. Authors have questioned the utility of artificial nests: they often provide results that vary from natural nests, thus I propose they are best seen as generators of hypotheses to be tested at natural nests. Many studies investigated nest success based on the distance to the edge of the forest or woodland, with equivocal results. Yet fragment size, structure and faunal assemblage set in a more complex paradigm may better explain the presence or absence of effects at edges. There are various types of evidence used to identify nest predators. I argue that cameras are the most functional and direct observations are the most informative. A large number and variety of nest predators are reported yet reviews of nest predation call for more information on the identity and roles of nest predators, particularly on those that add predation pressure beyond what the prey might be able to sustain. The impact of nest characteristics: type, height, vegetation layer, concealment and re-nesting were found to be equivocal in relation to nest predation and in need of focussed research on phylogenetic groups and guilds present within assemblages and within the context of assemblages. A handful of research studies have looked at the possible conservation actions of culling nest-predators and placing cages around threatened birds. More such studies are needed because they provide direct information about practical interventions. Research within assemblages is required to identify and elucidate the roles of nest predators and prey responses and to generate broad and useful theories, which may better inform conservation models.

scholarly journals Nestling begging calls increase predation risk by corvids

2019 ◽  
Vol 69 (2) ◽  
pp. 137-155
Author(s):  
Magne Husby
Keyword(s):  
Nest Predation ◽  
Predation Rate ◽  
Artificial Nest ◽  
Auditory Cues ◽  
Artificial Nests ◽  
Breeding Failure ◽  
Nestling Begging ◽  
Real Costs ◽  
Insight Into ◽  
Nest Predators

Abstract Despite nest predation being the most common cause of breeding failure in open-nesting birds, we have little insight into the cues used by nest predators when they search for nests. So far we have assumed that nest-predating birds are visually oriented while mammal predators to a large extent use scent and auditory cues like nestling begging calls. To evaluate how important nestling begging calls are for corvid nest predators searching for nests, I used artificial nests, which made it possible to find the real costs of the begging without mitigation by parental and nestling behavior. I used paired artificial nests, one with and one without nestling begging call playback. Within 10 days, 62.9% of the nests were predated. The analyses showed that nests with begging calls suffered a significantly higher predation rate than nests without begging calls, especially when the nests were placed close to corvid nests. Moreover, nests with begging calls were predated significantly earlier than nests without begging calls. In artificial nest pairs with both nests predated but on different days, nests with begging calls were predated first. In nest pairs with only one predated nest, nests with begging calls were predated most often. This experiment shows that nestling begging calls imply a cost in terms of increased and earlier nest predation, and that corvids use nestling begging calls as a cue to find and depredate bird nests, challenging earlier expectations.

Parent birds assess nest predation risk: influence of cavity condition and avian nest predator activity

2017 ◽  
Vol 48 (5) ◽  
pp. 691-699
Author(s):  
Jongmin Yoon ◽  
Jung-Shim Jung ◽  
Eun-Jin Joo ◽  
Byung-Su Kim ◽  
Shi-Ryong Park
Keyword(s):  
Predation Risk ◽  
Nest Predation ◽  
Avian Nest ◽  
Nest Predator

scholarly journals Macroecology of North European Wet Grassland Landscapes: Habitat Quality, Waders, Avian Predators and Nest Predation

2021 ◽  
Vol 13 (15) ◽  
pp. 8138
Author(s):  
Michael Manton ◽  
Per Angelstam
Keyword(s):  
Developmental Stage ◽  
Habitat Quality ◽  
Nest Predation ◽  
Relative Rate ◽  
Predation Pressure ◽  
Ecological Processes ◽  
Artificial Nests ◽  
Wet Grassland ◽  
Nest Loss ◽  
Nest Predators

Wet grassland degradation is a global issue that involves both altered land cover patterns and ecological processes, which affect the distribution and abundance of species. The sharp decline in European wader bird (Charadrii) populations is a good example. The aim of this study is to test the hypothesis that the anthropogenic developmental stage of wet grassland habitats and landscapes drives avian nest predator abundance, and thus the predation pressure on nests, which is a major cause of wader bird declines. Using a macroecological approach we selected six wet grassland landscapes representing a gradient in both grassland habitat development and breeding wader population status in four European countries (Belarus, Iceland, Lithuania and Sweden). We (1) mapped wader and avian predator assemblages in multiple wet grassland patches in each landscape, (2) used artificial nests to estimate the relative rate of egg predation, and (3) analyzed relationships between nest predation pressure, corvid nest predators versus raptors, nest loss and the stage of wet grassland habitat and landscape development. We found (1) inverse relationships between the abundance of corvids and waders, as well as between wet grassland developmental stage and waders, and (2) a positive correlation between the probability of nest loss and the density of corvid birds. In conclusion, we found a clear macroecological pattern linking habitat quality, wader populations, nest predators and nest predation. These linkages stress the importance of including nest predation as a factor limiting wader bird populations, and that corvid control or management may be useful management tools.

scholarly journals Nest caging as a conservation tool for threatened songbirds

2014 ◽  
Vol 41 (7) ◽  
pp. 598 ◽  
Author(s):  
Richard E. Major ◽  
Michael B. Ashcroft ◽  
Adrian Davis
Keyword(s):  
Reproductive Success ◽  
Nest Success ◽  
Nesting Success ◽  
Wire Mesh ◽  
Management Tool ◽  
Negative Effects ◽  
Artificial Nests ◽  
Endangered Population ◽  
Precocial Birds ◽  
Nest Predators

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.

scholarly journals Artificial Nest Predation and Abundance of Birds Along an Urban Gradient

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 838-847 ◽  
Author(s):  
Jukka Jokimäki ◽  
Esa Huhta
Keyword(s):  
Nest Predation ◽  
Predation Rate ◽  
Forest Area ◽  
Urban Gradient ◽  
Artificial Nest ◽  
Artificial Nests ◽  
Avian Predators ◽  
Avian Nest ◽  
Town Center ◽  
The Town

Abstract We studied nest predation pressure on birds along an urban gradient in urban parks in three Finnish towns. Artificial ground nests with Japanese Quail (Coturnix coturnix japonicus) eggs were depredated more in the urban area than in the adjacent forest area. Within each town, the nest predation rate was higher in the town center than in the less urbanized area of detached houses. Predation rates did not vary from year to year or between study towns. Abundances of generalist avian predators were higher in the town center than in the area of detached houses and in the surrounding forest area. Most of the nests in the town center were destroyed by avian predators. Predation rate of artificial nests in each of the town areas was higher in managed parks than in unmanaged parks, presumably due to the less dense vegetation in the managed than the unmanaged parks. A test involving covering nests revealed that artificial nests covered by adjacent vegetation survived better than nests with less cover. In our study, artificial nest loss reflected the distribution of avian nest predators. Ground nesters were present at lower abundances in areas where concealing vegetation was missing and avian nest predation was high. Apparently, nest predation is one of the several possible mechanism affecting urban bird assemblages.

The Pied Currawong's role in avian nest predation: a predator removal experiment

2001 ◽  
Vol 7 (3) ◽  
pp. 154 ◽  
Author(s):  
Graham R. Fulton ◽  
Hugh A. Ford
Keyword(s):  
Nest Predation ◽  
Bird Species ◽  
Artificial Nests ◽  
Predator Removal ◽  
Rural Landscapes ◽  
Before And After ◽  
Eucalypt Woodland ◽  
Avian Nest ◽  
High Level

Pied Currawongs Strepera graculina have been implicated as a major threat to the persistence of small passerines in urban and rural landscapes through their intense nest predation while raising their young. Pied Currawongs have recently increased in abundance and colonized new areas, due to the planting of exotic berry-bearing trees and shrubs. In association with habitat fragmentation, this may have intensified their predatory impact. We measured the rate of predation on 416 artificial nests, using quail and plasticine eggs, in a 240 ha remnant of eucalypt woodland. Nests were placed in one grid from which Pied Currawongs were removed and in one control grid. The level of predation was monitored before and after Pied Currawong removal. Overall, nest predation was extremely high with 91 % of all nests preyed upon in seven days. Moreover, nest predation decreased significantly following Pied Currawong removal, thus identifying them as significant nest predators. However, imprint evidence from plasticine eggs and the remains of real eggs indicate that other animals, particularly other birds, are also important predators. If this high level of nest predation is reflected in real nests and occurs over a number of years, it may lead to low recruitment of open-nesting birds at this site. If it occurs regionally, it could contribute to long term declines of these species. Our findings suggest that even quite large woodland fragments may be too small to sustain many declining bird species.

Indicators of avian nest predation and parental activity in a managed boreal forest: an assessment at two spatial scales

2005 ◽  
Vol 35 (2) ◽  
pp. 374-382 ◽  
Author(s):  
Jacques Ibarzabal ◽  
André Desrochers
Keyword(s):  
Landscape Structure ◽  
Nest Predation ◽  
Spatial Scales ◽  
Edge Length ◽  
Nesting Success ◽  
Tamiasciurus Hudsonicus ◽  
Indirect Measure ◽  
Indirect Measures ◽  
Total Core Area ◽  
Nest Predators

Studies of avian nesting success at the landscape level often use a single indirect measure to evaluate nest predation or parental activity. During two summers at Forêt Montmorency, Quebec, we analyzed and compared three indirect measures of nest predation risk: detection of two nest predators, (1) red squirrel (Tamiasciurus hudsonicus Erxleben) and (2) gray jay (Perisoreus canadensis L.), (3) depredation of bait, and direct observations of parental activity (mostly food transported by adults) at 316 stations over a 230-km2 area. We assessed the relationship between these indicators and three landscape-structure variables (total forested area, total core area, and total edge length) at two spatial scales (83 and 1610 ha). Nest predators were generally present at <30% of stations, <20% of baits were depredated, and >40% of stations exhibited evidence of broods. Bait depredation and the detection of jays or squirrels were correlated, but we found no associations between nest predation and parental activity indicators. Indicators of nest predation and parental activity were not significantly heterogeneous over the study area, despite substantial variation of landscape structure. We argue that parental activity indicators may be more reliable than nest predation indicators, but only as a coarse way to detect variation in nesting success.

Effect of partial cutting on predation risk to artificial bird nests

1999 ◽  
Vol 29 (12) ◽  
pp. 1911-1915 ◽  
Author(s):  
J Douglas Steventon ◽  
Peter K Ott ◽  
Kenneth L MacKenzie
Keyword(s):  
Predation Risk ◽  
Nest Predation ◽  
Basal Area ◽  
Predation Rate ◽  
Nesting Success ◽  
Partial Cutting ◽  
Artificial Nests ◽  
Detectable Difference ◽  
Predation Rates ◽  
Rule Out

Based on relative abundance data, partial cutting has been suggested as a technique to maintain habitat for birds associated with late-seral forests, but there has been little study of partial cutting effects on nesting success. One of the primary limitations to nesting success is nest predation. We compared predation rates (proportion of nests disturbed in a 14-day period) in partially cut (30 or 60% basal area removal), clearcut, and uncut forests in northwestern British Columbia, in two experiments using ground-placed (1993) and shrub-placed (1998) artificial nests. In the ground-nest experiment there was a very low predation rate (0.06) and no detectable difference among treatments (p = 0.403). In the shrub-nest experiment, there was a 0.36 predation rate and little evidence of treatment differences (p = 0.295). Based on 90% confidence intervals for differences in observed predation rate, the 30% removal clearly did not increase predation risk relative to uncut forest. With the 60% removal, however, we cannot rule out a possible increase in predation risk compared with either uncut forest or clearcuts.

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