Predation of artificial ground nests in Australian tropical savannas: inverse edge effects

2005 ◽  
Vol 32 (4) ◽  
pp. 313 ◽  
Author(s):  
Fiona J. Fraser ◽  
Peter J. Whitehead
Keyword(s):  
Nest Predation ◽  
National Park ◽  
Tropical Savanna ◽  
Northern Australia ◽  
Artificial Nest ◽  
Tropical Savannas ◽  
Artificial Nests ◽  
Predator Identity ◽  
High Diversity ◽  
Predation Rates

Depredation of artificial ground nests was examined in tropical savanna in northern Australia to assess potential predation pressures on nests of the partridge pigeon (Geophaps smithii), a declining tropical granivore. Predation rates were examined at two sites, Kakadu National Park (which supported a relatively high density of partridge pigeons) and Berry Springs (which had greater habitat fragmentation and comparatively low partridge pigeon density). The effects of distance from road, understorey structure, topography and nest-microsite concealment on nest predation rates were examined. Artificial-nest predation rates were greater at 150 m from roads than <1 m from the roadside. Predation rates did not vary with understorey structure, topography, or level of nest concealment. There was marked variation between sites, with predation levels at Kakadu more than double those recorded for Berry Springs. Discerning predator identity, or even the size of a predator, from marks left in clay eggs proved difficult and was possible for ~35% of predation events. Of these, 42% of predation events involved predators of a size we considered too small to take a natural partridge pigeon nest. We suggest that extrapolation from artificial to natural ground-nest predation rates be undertaken with caution for landscapes such as Australia’s tropical savanna, which supports a high diversity and abundance of small potential predators of artificial nests. There was no evidence of predation by birds, and the methodology proved inadequate for identifying predation by feral cats (Felis catus).

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 Predation of experimental nests is linked to local population dynamics in a fragmented bird population

2011 ◽  
Vol 7 (6) ◽  
pp. 954-957 ◽  
Author(s):  
Matthias Vögeli ◽  
Paola Laiolo ◽  
David Serrano ◽  
José L. Tella
Keyword(s):  
Real World ◽  
Nest Predation ◽  
Local Population ◽  
Structured Populations ◽  
Life History Strategies ◽  
Artificial Nest ◽  
Artificial Nests ◽  
Bird Populations ◽  
Local Populations ◽  
Predation Rates

Artificial nest experiments (ANEs) are widely used to obtain proxies of natural nest predation for testing a variety of hypotheses, from those dealing with variation in life-history strategies to those assessing the effects of habitat fragmentation on the persistence of bird populations. However, their applicability to real-world scenarios has been criticized owing to the many potential biases in comparing predation rates of artificial and natural nests. Here, we aimed to test the validity of estimates of ANEs using a novel approach. We related predation rates on artificial nests to population viability analyses in a songbird metapopulation as a way of predicting the real impact of predation events on the local populations studied. Predation intensity on artificial nests was negatively related to the species' annual population growth rate in small local populations, whereas the viability of large local populations did not seem to be influenced, even by high nest predation rates. The potential of extrapolation from ANEs to real-world scenarios is discussed, as these results suggest that artificial nest predation estimates may predict demographic processes in small structured populations.

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.

Visual cues do not increase artificial nest predation in a Brazilian tropical savanna

2021 ◽  
Author(s):  
Paulo Victor Resende dos Santos ◽  
Ingrid Pinheiro Paschoaletto ◽  
Lia Nahomi Kajiki ◽  
Mariana de-Carvalho ◽  
Samara de Albuquerque Teixeira
Keyword(s):  
Nest Predation ◽  
Visual Cues ◽  
Tropical Savanna ◽  
Artificial Nest

Predation on different-sized quail eggs in an artificial-nest study in western Newfoundland

1999 ◽  
Vol 77 (7) ◽  
pp. 1170-1173 ◽  
Author(s):  
Keith P Lewis ◽  
William A Montevecchi
Keyword(s):  
Japanese Quail ◽  
Small Mammals ◽  
Nest Predation ◽  
Egg Size ◽  
Tamiasciurus Hudsonicus ◽  
Buffer Strips ◽  
Artificial Nest ◽  
Red Squirrels ◽  
Artificial Nests ◽  
Riparian Buffer Strips

In artificial-nest studies, Japanese Quail (Coturnix japonica) eggs have been used as surrogates for passerine eggs, although small mammals that prey on passerine eggs may be unable to consume Japanese Quail eggs. To determine the influence of egg size on nest predation in different landscapes on insular Newfoundland, we placed either a Japanese Quail egg or a smaller Chinese Painted Quail (Xexcalfactoris chinensis) egg in artificial ground nests along lakeshore forest edges and along riparian buffer strips. Clay eggs were used to identify nest predators. Levels of predation on nests with Japanese Quail and Chinese Painted Quail eggs were similar. Based on clay eggs, predation was attributed to red squirrels (Tamiasciurus hudsonicus), and we found no evidence that smaller mammals preyed on artificial nests. We conclude that the Japanese Quail egg is acceptable for use in artificial-nest studies in Newfoundland, and we discuss the implications of egg size and small mammals in nest-predation experiments.

Artificial nest predation rates vary among habitats in the Australian monsoon tropics

2007 ◽  
Vol 23 (3) ◽  
pp. 519-527 ◽  
Author(s):  
Richard A. Noske ◽  
Sarah Fischer ◽  
Barry W. Brook
Keyword(s):  
Nest Predation ◽  
Artificial Nest ◽  
Australian Monsoon ◽  
Predation Rates

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.

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.

Sign in / Sign up

Export Citation Format

Share Document