scholarly journals Predation on Real and Artificial Nests in Shrubsteppe Landscapes Fragmented by Agriculture

The Condor ◽  
2002 ◽  
Vol 104 (3) ◽  
pp. 496-506 ◽  
Author(s):  
W. Matthew Vander Haegen ◽  
Michael A. Schroeder ◽  
Richard M. DeGraaf
Keyword(s):  
Nest Predation ◽  
Survival Rates ◽  
Predation Rate ◽  
Future Research ◽  
Fragmented Landscape ◽  
Corvus Corax ◽  
Artificial Nests ◽  
Fragmented Landscapes ◽  
Eastern Washington ◽  
Predation Rates

Abstract Clearing of shrubsteppe communities for agriculture has created a highly fragmented landscape in eastern Washington, a condition that has been shown to adversely affect nesting success of birds in some forest and grassland communities. We used artificial nests monitored by cameras to examine relative effects of fragmentation, distance to edge, and vegetation cover on nest predation rates and to identify predators of shrubsteppe-nesting passerines and grouse. Predation rate for artificial nests was 26% (n = 118). Fragmentation had a strong influence on predation rates for artificial nests, with nests in fragmented landscapes about 9 times more likely to be depredated as those in continuous landscapes. Daily survival rate (± SE) for 207 real nests of 4 passerine species also was greater in continuous (0.978 ± 0.004) than in fragmented (0.962 ± 0.006) landscapes, although pattern of predation between real and artificial nests was not consistent among sites. Artificial nests were depredated by Common Ravens (Corvus corax), Black-billed Magpies (Pica hudsonia), Sage Thrashers (Oreoscoptes montanus), least chipmunks (Tamias minimus), and mice. Most nests in fragments were depredated by corvids (58%), whereas only Sage Thrashers and small mammals depredated nests in continuous landscapes. Increased predation by corvids and lower nest success in fragmented landscapes may have played a part in recent declines of some shrubsteppe birds. Future research should measure annual reproductive success of individual females and survival rates of juveniles and adults. Depredación de Nidos Naturales y Artificiales en Paisajes de Estepa Arbustiva Fragmentados por Agricultura Resumen. El reemplazo de estepa arbustiva por campos de cultivo ha creado un paisaje altamente fragmentado en el este de Washington, afectando adversamente el éxito de nidificación de aves en algunas comunidades de bosque y pastizal. Usamos nidos artificiales monitoreados por cámaras para examinar los efectos relativos de la fragmentación, la distancia al borde y la cobertura de la vegetación sobre las tasas de depredación de nidos, y para identificar los depredadores de paserinos y gallinas silvestres (Phasianidae) que nidifican en la estepa arbustiva. La tasa de depredación de los nidos artificiales fue del 26% (n = 118). La fragmentación tuvo una fuerte influencia en las tasas de depredación de nidos artificiales, ya que los nidos en paisajes fragmentados tuvieron una probabilidad de ser depredados 9 veces mayor que aquellos en paisajes continuos. La tasa de supervivencia diaria (± EE) de 207 nidos naturales pertenecientes a 4 especies de paserinos también fue mayor en paisajes continuos (0.978 ± 0.004) que fragmentados (0.962 ± 0.006), aunque el patrón de depredación entre nidos naturales y artificiales no fue consistente entre sitios. Los nidos artificiales fueron depredados por Corvus corax, Pica hudsonia, Oreoscoptes montanus, Tamias minimus y ratones. La mayoría de los nidos en fragmentos fueron depredados por C. corax (58%), mientras que sólo O. montanus y pequeños mamíferos depredaron nidos en paisajes continuos. Un incremento en la depredación por parte de C. corax y un menor éxito de los nidos en paisajes fragmentados puede haber jugado un rol en la disminución de algunas aves de la estepa arbustiva. Futuras investigaciones deberían medir el éxito reproductivo anual de hembras individuales y las tasas de supervivencia de juveniles y adultos.

scholarly journals Do Repugnant Scents Increase Survival of Ground Nests? A Test with Artificial and Natural Duck Nests

2007 ◽  
Vol 121 (2) ◽  
pp. 150
Author(s):  
Vanessa B. Harriman ◽  
Justin A. Pitt ◽  
Serge Larivière
Keyword(s):  
Human Hair ◽  
Nest Predation ◽  
Survival Rates ◽  
Olfactory Cues ◽  
Artificial Nests ◽  
Treatment Groups ◽  
Mammalian Predators ◽  
High Predation ◽  
Ground Nesting ◽  
Predation Rates

Ground-nesting birds typically experience high predation rates on their nests, often by mammalian predators. As such, researchers and wildlife managers have employed numerous techniques to mitigate nest predation. We investigated the use of scents as repellents to deter predators from both artificial and natural ground nests. Survival rates of artificial nests did not differ among six groups of substances (Wald ?2 df = 5 = 4.53, P < 0.48); however the chronology of predation among groups differed. A commercial Coyote urine based deterrent (DEER-D-TERTM), human hair, and Worcestershire sauce were depredated faster than the control (F4,5 = 40.3, P < 0.001). Nest survival of natural nests differed among those groups tested (Wald ?2 df = 2 = 11.8, P < 0.005); the eight mothball treatment decreased survival (Wald ?2 df = 1 = 11.5, P < 0.005), which indicated that novel smells may attract predators or result in duck nest abandonment when coupled with natural duck scent. Chronologies of predation events among treatment groups were not different for natural nests (F2,3 = 1.9, P = 0.22). These findings indicate an interaction between novel scents and predator olfactory cues.

scholarly journals Evaluation of factors associated with predation on Caiman latirostris nests (Crocodylia: Alligatoridae) in Argentina

2016 ◽  
Vol 15 (2) ◽  
pp. 137 ◽  
Author(s):  
Melina Soledad Simoncini ◽  
María Virginia Parachú Marcó ◽  
Thiago Costa Gonçalves Portelinha ◽  
Carlos Ignacio Piña
Keyword(s):  
Human Disturbance ◽  
Nest Predation ◽  
Visual Cues ◽  
Survival Rates ◽  
Predation Rate ◽  
Nest Sites ◽  
The North ◽  
Natural Predation ◽  
Maternal Presence ◽  
Predation Rates

Predation is a major cause of crocodilian egg loss. However, at present, the mechanisms by which predators detect nests is unknown. Previous studies have reported that predators are able to detect prey using both visual and olfactory cues. This study aims to determine the natural predation rate on Broad-snouted Caiman (Caiman latirostris) nests in a “normal” year (i.e., no extreme climatic events) and whether olfactory or visual cues attract predators to caiman nests, and to evaluate the effect of maternal presence on nest predation. In December 2010, we searched for nests in the north of Santa Fe Province, Argentina. Each nest was assigned to one of the following treatments: (1) control nests (nests were observed from a distance to avoid disturbance), (2) visual attraction nests (yellow flagging tapes were tied to vegetation around the nest), (3) olfactory attraction nests (nests were opened, one egg from the clutch was broken, and then the nests were covered again), (4) olfactory attraction from human disturbance (material was manipulated by researchers). The natural predation rate on broad-snouted caiman nests was found to be 21% during the nesting season. Both olfactory and visual cues were associated with increased predation rates, and human disturbance was strongly associated with increased nest predation at terrestrial sites. Predation rates were less at nests attended by female caiman. Management programs that harvest eggs in wild populations (ranching) are predicated on the assumption that removal of some eggs is sustainable, because some will be lost to natural causes (e.g., predation and flooding) and the remaining hatchlings will have improved survival rates. To reduce nest predation of Broad-snouted Caiman between the time when the nest is found and when the eggs are collected, we propose to avoid identification of nest sites with highly visible markings (e.g., flagging tapes tied to vegetation around nests) and to collect eggs immediately after they are found

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.

scholarly journals Possible effects of nest predation on the breeding success of Ferruginous Ducks Aythya nyroca

2006 ◽  
Vol 16 (4) ◽  
pp. 309-316 ◽  
Author(s):  
JENŐ J. PURGER ◽  
LÍDIA A. MÉSZÁROS
Keyword(s):  
Wild Boar ◽  
Breeding Success ◽  
Nest Predation ◽  
Survival Rates ◽  
Predation Rate ◽  
Water Levels ◽  
Conservation Area ◽  
Artificial Nests ◽  
Management Measures ◽  
Nesting Sites

To investigate whether nest predation can influence the breeding success of Ferruginous Ducks Aythya nyroca, artificial nests were used in Nagyberek, the strictly protected swamp pond of the Juniper Woodland Nature Conservation Area (Somogy county, south Hungary). Experimentation lasted for 4 weeks, a similar length of time to the incubation period of Ferruginous Ducks. After 1 week, 80% of nests were intact, after 2 weeks only 46%, and after 3 and 4 weeks only 2% remained undamaged. Nest survival rates were not affected by the width of the sedge stands, but as water levels surrounding nests decreased, nests became more accessible to Wild Boar Sus scrofa and other land mammal predators, which increased the rate of predation. Artificially maintaining water levels would not only decrease the predation rate of nests, but would also maintain feeding areas for ducks. Wild Boar were the main cause of clutch loss in this area, and therefore by management measures, such as a reduction in their abundance or attracting them away from potential nesting sites by providing food elsewhere, the breeding success of the Ferruginous Ducks may be further improved.

Predation rates of artificial nests in the edge and interior of a southern Victorian forest

2002 ◽  
Vol 29 (4) ◽  
pp. 341 ◽  
Author(s):  
Lainie Berry
Keyword(s):  
Small Mammals ◽  
Nest Predation ◽  
Forest Edge ◽  
Forest Edges ◽  
Artificial Nests ◽  
Avian Predators ◽  
Forest Interior ◽  
Grey Shrike ◽  
Predation Rates

Predation rates of nests at human-induced habitat edges may be greater than in forest interior due to differences in predator assemblages and predator activity. I compared the predation rates on 192 artificial nests containing plasticine eggs placed in forest edge and interior sites at Bunyip State Park, Victoria. The nest-predation rates at the forest edge sites were significantly greater (mean = 52–58%) than that at the forest interior sites (mean = 30–39%). The relative rates of predation by birds compared with mammals were significantly greater at forest edge sites (mean = 78–94%) than at forest interior sites (mean = 36–67%). Higher rates of nest predation at forest edges appeared to be due to greater densities of avian predators such as the grey shrike-thrush (Colluricincla harmonica), and/or lower abundances of small mammals. However, biases towards certain predator types may mask real, or create false, patterns in predation rates of artificial nests. A better understanding of how predators respond to artificial nests compared with natural nests is required. Until then, results of predation studies that use artificial nests should be interpreted with caution.

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.

Is the risk of nest predation heterospecifically density-dependent in precocial species belonging to different nesting guilds?

2011 ◽  
Vol 89 (12) ◽  
pp. 1164-1171 ◽  
Author(s):  
Johan Elmberg ◽  
Hannu Pöysä
Keyword(s):  
Nest Predation ◽  
Predation Rate ◽  
Apparent Competition ◽  
Artificial Nests ◽  
Nest Cavity ◽  
Density Dependent ◽  
Pine Martens ◽  
Cavity Nest ◽  
The One ◽  
Cavity Nests

Nest predation is a key source of mortality and variation in fitness, but the effect co-occurring species belonging to different nesting guilds have on each other’s nest success is poorly understood. By using artificial nests, we tested if predation on cavity nests of Common Goldeneyes ( Bucephala clangula (L., 1758)) is increased in the presence of ground nests of Mallards ( Anas platyrhynchos L., 1758) and vice versa. Specifically, by adding ground nests in the vicinity of cavity nests, we tested the hypothesis that predation on cavity nests is heterospecifically density-dependent. A shared predator, the pine marten ( Martes martes (L., 1758)), was intensively hunted in one of the study areas, but not in the other, leading to most individuals in the former being naïve immigrants. Cavity-nest fate was not affected by addition of ground nests. Similarly, ground-nest survival did not decrease when nearby cavity nests were depredated. Fate of nests in a given nest cavity was highly predictable between years in the study area with minimal removal of pine martens, but not in the one with intensive removal. Predation rate was higher on cavity nests than on ground nests. Predation on ground nests was lower in the study area with intensive removal of pine martens. We conclude there was neither apparent competition between guilds nor heterospecific density-dependence in predation risk.

scholarly journals Artificial nest predation rates vary depending on visibility in the eastern Brazilian Amazon

2014 ◽  
Vol 44 (3) ◽  
pp. 393-396 ◽  
Author(s):  
Fernanda Michalski ◽  
Darren Norris
Keyword(s):  
Nest Predation ◽  
Generalized Linear Model ◽  
Nest Site ◽  
Experimental Studies ◽  
Basal Area ◽  
Artificial Nest ◽  
Artificial Nests ◽  
Eastern Brazil ◽  
Systematic Biases ◽  
Predation Rates

Observational and experimental studies have shown that increased concealment of bird nests reduces nest predation rates. The objective of the present study was to evaluate differences in predation rates between two experimental manipulations of artificial ground nests (i.e., clearing an area around the artificial nest or leaving it as natural as possible), and test whether environmental variables also affected nest predation in an undisturbed area of Amazonian forest in eastern Brazil. A generalized linear model was used to examine the influence of five variables (manipulation type, perpendicular distance from the main trail, total basal area of trees surrounding the nest site, understorey density, and liana quantity) on nest predation rates. Model results, showed that manipulation type was the only variable that significantly affected nest predation rates. Thus, to avoid systematic biases, the influence of nest site manipulation must be taken into consideration when conducting experiments with artificial nests.

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.

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.

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