High Nest Predation Rates Research Articles

Flash in the pan: how grassland renewal affects reproduction of Northern Lapwings Vanellus vanellus

ABSTRACTCapsule: Grassland renewal is associated with short-term beneficial effects on density and reproduction of Northern Lapwings Vanellus vanellus followed by long-lasting reduced breeding numbers after sward establishment.Aims: To assess short- and long-term effects of grassland renewal on the reproduction of Northern Lapwings.Methods: In the years 1999–2011 we counted breeding Northern Lapwings on 18 reseeded grassland plots in a chronosequence ranging from one year before until 3 years after reseeding. We also monitored nesting dispersion and hatching success in different habitats, particularly tillage, permanent grasslands and reseeded grasslands during sward establishment.Results: Grassland that underwent reseeding possessed several-fold more Northern Lapwings during the phase of sward establishment than before. In the subsequent years, breeding numbers significantly declined and remained low throughout the study period. In recently reseeded grassland, Northern Lapwings tended to breed in larger colonies. Although habitat-specific differences in hatching success were not significant, we found significantly higher nest predation rates in agriculturally improved grasslands than in tillage and reseeded grasslands during sward establishment.Conclusions: Due to its long-term adverse effects on density and reproduction of Northern Lapwings, grassland renewal should not be practised in areas with conservation responsibilities for grassland-breeding waders.

Predation on artificial avian nests is higher in forests bordering small anthropogenic openings

Habitat edges alter the diversity of avian communities and are often associated with higher rates of nest predation. However, most previous studies on habitat edges have been conducted along long linear corridors or at the transition between large field and forest patches in agricultural systems. Less is known about predation rates when the habitat edge is the result of a small interior forest opening. We assessed predation rates on artificial nests mimicking ground and shrub nesters in Northern Michigan forests perforated by small clearings used previously for oil and gas extraction. Nests were placed at varying distances from the edges of these clearings, and in similar spatial arrangements within unfragmented interior forest plots. Predation rates increased in forests near edges, but significant impacts were limited to shrub nests. Markings on predated clay eggs indicated that the type of predation also differed. Scratch marks were the most prevalent egg indentation, but eggs with poked holes were twice as common near the forest edge. The increase in the number of poked eggs suggests that a higher density of avian predators occurred in forests near an edge. Predation rates at forest edges did not vary by distance from the forest edge. Surveys of the avian community revealed differences between edge and interior forests: American Crows Corvus brachyrhynchos and Blue Jays Cyanocitta cristata, two species known to predate bird nests, were more common near edges. Our results suggest that small forest openings alter the avian community and may adversely impact reproductive output in some species. If the alteration of these processes results in population‐level impacts, small forest perforations should be avoided when possible and reforestation of abandoned well‐pads should be encouraged.

Mismatches between habitat preferences and risk avoidance for birds in intensive Mediterranean farmland

Land use intensification may create habitats that organisms perceive as suitable, but where reproduction or survival is insufficient to maintain self-sustaining populations. Such conditions may qualify as ecological traps, but their existence is often hard to prove. Here, we provide a practical framework to evaluate a potential ecological trap resulting from mismatch between habitat preferences and predation risk, focusing on ground-nesting farmland birds of conservation concern. The framework is based on species-specific associations with safe or unsafe habitat types (i.e. field and landscape types with high or low nest survival), and the occurrence of risk avoidance (i.e. negative responses to predator abundances or to nest failure rates after controlling for habitat effects). Bird densities were far more influenced by field characteristics than landscape context. Corn bunting and fan-tailed warbler were associated with tall swards (safe habitats), and did not show risk avoidance. Tawny pipit and and Galerida larks were associated with short swards (unsafe habitats), with the former avoiding fields with high nest predation rates, and the later avoiding high mongoose abundances. Short-toed lark was associated with fields with short swards and low nest trampling rates. Results suggest that short-toed lark may be the most vulnerable to ecological trapping, because it nests on unsafe habitats and did not show predation risk avoidance. Our approach provides a practical first step to infer vulnerability to a potential ecological trap, though further research is needed to confirm this effect. Management actions increasing nest survival in short sward fields will likely favour grassland bird conservation in intensive Mediterranean farmland.

Antipredator Behavior of Adult and Nestling Red-winged Blackbirds (Agelaius phoeniceus)

ABSTRACT Red-winged Blackbirds (Agelaius phoeniceus) experience high rates of nest predation and are therefore expected to exhibit adaptations to reduce the risk of eavesdropping by predators. We used a simulated predator and observations of adult and nestling behavior to test predictions of the predator eavesdropping hypothesis. Females (n = 42) delayed their feeding visits significantly longer and took significantly longer to complete their round trips when a plastic American crow (Corvus brachyrhynchos) was 20 m from their nests than when a black wood block was at the same location, but time spent off territory foraging did not differ significantly. Nestlings (n = 35 broods) begged appropriately (in response to a female at the nest) significantly less and at significantly lower intensity when the plastic crow was 20 m from their nests than when the wood block was at the same location, but the crow had no significant effect on the amount or intensity of inappropriate (no female present) begging. These a...

Agri-evironmental schemes and active nest protection can increase hatching success of a reintroduced farmland bird species

Throughout Europe ground-nesting farmland bird species are rapidly declining and have become a conservation concern. Intensive agriculture and high nest predation rates are major factors causing the decline. Species conservation efforts often focus on habitat enhancement to increase the quantity and quality of available habitat structures (habitat enhancement hypothesis) or active nest protection by fencing and predator control (predation mitigation hypothesis). Within the context of a reintroduction project of grey partridges (Perdix perdix) into two regions of Switzerland, we investigated breeding habitat preferences and hatching success in relation to properties of the habitat surrounding the nest. Then we tested whether predator exclusion by fencing can increase hatching success. The location and hatching success of 121 nests were observed by radio-tracking and available habitats in both regions were mapped. Grey partridges preferred nesting habitats in highly heterogeneous wildflower areas, which had been implemented as biodiversity promoting areas (BPA) and nest fencing significantly increased hatching success. Likewise, increased proportions of wildflower BPAs tended to enhance hatching success, which is probably related to higher availability of cover in these structures. Increasing proportions of cover vegetation around the nest had a positive effect on hatching success. Increasing the quality of rural habitats by providing heterogeneous habitat structures as well as reducing predator access to nests by fencing can increase hatching success in grey partridges and is likely to benefit other ground-nesting birds as well. In fact, high amounts of cover vegetation around the nest can compensate for nest fencing by hampering nest depredation.

Indirect effects of invasive Burmese pythons on ecosystems in southern Florida

SummaryInvasive predators can dramatically alter ecosystems through both direct predation and indirect effects such as tropic cascades. However, most examples of top‐down effects of invasive predators in terrestrial systems stem from islands or similar low‐diversity ecosystems. Snakes are an emerging guild of damaging invasive predators, but demonstration of ecosystem‐level impacts of invasive snakes are limited to the single case of the brown treesnake on Guam.Invasive Burmese pythons are firmly established in southern Florida and have been linked to severe (80–100%) declines of several previously common mammal species (e.g. raccoons, opossums and rabbits). Specifically, spatiotemporal patterns of mammal declines in the Everglades mirror the spread of pythons and experimental reintroductions of rabbits to areas where they had been extirpated failed due to high (77% of mortalities) rates of predation by pythons.I evaluated the potential indirect effects of pythons on the nesting success of oviparous species by monitoring artificial turtle nests (N = 183) at 13 sites across the expanding range of the python population. I documented few mammals and low rates of nest predation (average score = 1·5 on a 1–5 scale) in the southern Everglades where pythons have been established the longest, intermediate (average score = 2·3) rates of nest predation at recently invaded sites, and very high (average score = 4·6) rates of nest predation at sites with few or no pythons. These findings represent the first documentation of potential indirect effects of pythons on non‐prey species, and suggest that loss or decline of mammals is resulting in trophic cascades that threaten the Everglades ecosystem.Synthesis and applications. My results suggest that an introduction of non‐native apex predators can result in trophic cascades that alter even complex, continental ecosystems. The Burmese python invasion of South Florida shows remarkable parallels with the catastrophic case of the brown treesnake in Guam, but in some ways is even more worrisome. Documentation of both strong direct impacts on prey and potential indirect effects on Everglades’ ecosystems within 15 years after being recognized as established emphasizes the need to integrate python management into restoration of the Greater Everglades Ecosystem. More broadly, non‐native snakes warrant significant attention for their potential to become damaging invasive species.

Daily survival rate of nests is lower in fruiting than non-fruiting tree species for a Hawaiian forest bird, the Kaua̒i ̒elepaio (Chasiempis sclateri)

ABSTRACT Nest-site characteristics are important drivers of nest success in birds, and are particularly important to understand in systems where anthropogenic factors may exacerbate their negative effects on population demographics. In Hawaii, it is suggested that forest bird nests in fruiting tree species may have higher rates of nest predation than in non-fruiting tree species, because fruit is an important dietary component of introduced rats. I assessed the differential daily survival rate (DSR) of nests of Kauai Elepaio (Chasiempis sclateri) on Kauai Island, Hawaii, in fruiting versus non-fruiting tree species using generalized linear models in program MARK. Nests were located in six fruiting tree species (n = 19) and one non-fruiting species (n = 25). Nest-tree reproductive strategy was a driver of DSR (β = −1.15 ± 0.55 SE, 95% CI = −2.23–-0.07) and DSR was lower in fruiting tree species compared to the non-fruiting species (0.975 vs. 0.992, respectively). Most nest failures were attributed to ...

The role of nest‐site selection and cereal production in differential nest predation in Common Quail Coturnix coturnix and hybrid quail C. coturnix × C. japonica

In Europe, farm‐reared quail used for restocking purposes are often hybrids between the Common Quail Coturnix coturnix and the Japanese Quail Coturnix japonica. These hybrids interbreed with wild Common Quail populations and suffer higher rates of nest predation, which would suggest that the two quail types have different nest‐site selection patterns. We monitored 103 radiotagged nesting females (77 wild Common Quail over 18 breeding seasons and 26 hybrid quail over six breeding seasons) and analysed their nest placement behaviour. Our results did not provide any evidence that the quail types showed different nest‐site selection trends, as they all preferred to nest near cereal field margins. The higher nest predation rate experienced by hybrids might therefore be explained by less effective anti‐predator behaviour among hybrid females during incubation. As no edge effect on nest predation was observed, the preference for nesting close to cereal margins could be due to the greater food resources of field margins. Moreover, Common Quail nest predation decreased with a rise in barley straw production, supporting evidence that nest cover plays an important role in the prevention of nest predation in this species. No such relationship was found for hybrid quail, but this result is not conclusive, as the data on barley straw production for hybrid quail covered a much smaller range of interannual variability. Barley straw production in Catalonia decreased significantly between 1992 and 2012, possibly as a result of a change in the barley varieties used. This practice could entail a conservation threat for ground‐nesting bird species.

Survival to independence in relation to pre‐fledging development and latitude in songbirds across the globe

Species differ strongly in their life histories, including the probability of survival. Annual adult survival was investigated extensively in the past, whereas juvenile survival, and especially survival to independence, received much less attention. Yet, they are critical for our understanding of population demography and life‐history evolution. We investigated post‐fledging survival to independence (i.e. survival upon leaving the nest until nutritional independence) in 74 species of passerine birds worldwide based on 100 population level estimates extracted from published literature. Our comparative analyses revealed that survival to independence increased with the length of nestling period and relative fledging mass (ratio of fledging mass to adult body mass). At the same time, species with higher nest predation rates had shorter nestling periods and lower relative fledging mass. Thus, we identify an important trade‐off in life history strategies: staying longer in the nest may improve post‐fledging survival due to enhanced flight ability and sensory functions, but at the cost of a longer exposure to nest predators and increased mortality due to nest predation. Additionally, post‐fledging survival to independence did not differ between species from the northern temperate zone vs species from the tropics and southern hemisphere. However, analyses of post‐fledging survival curves suggest that 1) daily survival rates are not constant and improve quickly upon leaving the nest, and 2) species in the tropics and southern hemisphere have higher daily post‐fledging survival rates than northern temperate species. Nevertheless, due to the accumulation of mortality risk during their much longer periods of post‐fledging care, overall survival until independence is comparable across latitudes. Obtaining high‐quality demographic data across latitudes to evaluate the generality of these findings and mechanisms underlying them should be a research priority.

Light grazing of saltmarshes increases the availability of nest sites for Common Redshank Tringa totanus, but reduces their quality

The breeding population of Common Redshank Tringa totanus on British saltmarshes has reduced by >50% since 1985, with declines linked to changes in grazing management. Conservation initiatives have encouraged low-intensity grazing of 0.5 cattle ha−1y−1 but even light grazing can lead to high rates of nest mortality. To avoid predators, Redshank nest in patches of tall vegetation, but the effects of grazing on the availability and quality of habitat selected by Redshank remain unclear. We investigated Redshank nest site selection in relation to cattle grazing and asked (a) which nest vegetation conditions do Redshank select and (b) does grazing limit the availability of higher quality nest sites? We characterised vegetation height and composition at nests and control locations on six saltmarshes grazed between 0 and 0.55 cattle ha−1y−1, which falls within or near the UK Environment Agency definition of light grazing. Redshank selected nest locations in the tallest vegetation available (26±13cm with no grazing), but grazing limited the availability of such tall vegetation (11±7cm at 0.55 cattle ha−1y−1). However, Redshank also selected nest locations dominated by the grass Festuca rubra, which increased with higher livestock densities. By causing Redshank to nest in shorter vegetation, but with more of their preferred grass species, grazing presented a trade-off for Redshank. As previous work has shown that nesting in shorter vegetation results in higher nest predation rates, results of this study suggest that even light conservation grazing can result in Redshank nesting in lower quality habitat. Reducing saltmarsh grazing levels below 0.55 cattle ha−1y−1 may therefore increase Redshank populations by maintaining a vegetation structure with patches of F. rubra but with longer sward heights for nesting.

Wing growth drives songbird selection

Life History Nestling birds are particularly vulnerable to predation, providing pressure for individuals to grow and leave the nest as quickly as possible. In contrast to temperate songbirds, tropical birds appear to grow more slowly despite high rates of nest predation. Martin shows that overall

Breeding season weather determines long‐tailed tit reproductive success through impacts on recruitment

Productivity is a key demographic trait that can be influenced by climate change, but there are substantial gaps in our understanding of the impact of weather on productivity and recruitment in birds. Weather is known to influence reproductive success in numerous species, although such effects have not been reported in all studies, perhaps because they are masked by high nest predation rates or buffered by density dependence. Here, we use a 19‐yr study of a population of individually marked long‐tailed tits Aegithalos caudatus to quantify the impacts of weather on productivity in the nest (from eggs to fledging) and subsequent recruitment, while taking nest predation rates and density dependence into account. We find that weather has negligible effects on clutch size, hatching success, brood size, probability of fledging and number of fledglings. Annual variation in nest predation rates is a strong predictor of productivity, but we find no evidence that the magnitude of nest predation is determined by weather. Recruitment was strongly associated with breeding season weather, even when taking density dependence effects into account. This contrasts with the conventional view that first year survival of temperate passerines is primarily determined by winter weather. Recruitment was reduced when March temperatures were high, perhaps caused by earlier peaks in caterpillar abundance and thus reduced food availability at the time of fledging. Recruitment increased following high May temperatures, perhaps due to an improved thermo‐regulatory environment for young fledglings. These opposing effects of warm March and May temperatures highlight the importance of considering asymmetrical rates of warming in different months when predicting climate change impacts.

Ecological traps and behavioural adjustments of urban songbirds to fine‐scale spatial variation in predator activity

AbstractThe influence of predators on bird populations is controversial and poorly understood, especially in urban areas where predator densities can be particularly high. We assessed if fine‐scale spatial variation in predator activity and proximity have direct and indirect effects on urban songbird distributions and breeding success, by testing the hypotheses that (1) songbirds that are sensitive to nest predation select territories with reduced activity of nest predators; (2) blackbird Turdus merula, a species that experiences high nest predation rates, lays smaller clutches in territories located in areas with higher numbers of nest predators as predicted by Skutch's hypothesis; (3) songbirds that are sensitive to nest predation have higher nest predation rates in areas with greater predator activity. We tested these hypotheses using two sites in urban Sheffield, UK, and focus on nest predatory corvids and grey squirrels Sciurus carolinensis. We found no evidence that songbirds that are most sensitive to nest predation adjust their territory location in response to fine‐scale spatial variation in predator distributions. It thus seems unlikely that urban predators are indirectly regulating urban bird population size by restricting habitat availability. Blackbirds did not vary their clutch size in response to predator distributions. These findings generate the potential for an ecological trap in which prey species fail to avoid areas with the highest concentrations of nest predators, or to exhibit behavioural adjustments to reduce the risk of nest predation at such sites. We find some evidence for such ecological traps as, while fine‐scale variation in grey squirrel occurrence and activity were not associated with nest predation rates, nests located in closer proximity to corvids and in areas with higher indices of corvid activity experienced slightly higher nest predation rates.

Reed Parrotbill nest predation by tidal mudflat crabs: Evidence for an ecological trap?

Understanding the relationships between nesting habitat quality and predation risk is essential for developing appropriate conservation management for threatened species. This is particularly relevant where anthropogenic pressures could decouple the environmental cues used by birds to assess nesting habitat quality from increased predation risk. In this study, we conducted a series of surveys and nest experiments to examine the nest predation rates of Reed Parrotbill (Paradoxornis heudei) a passerine bird between inland and tidal reed‐bed wetland habitats, at Yellow River Delta National Nature Reserve, Eastern China during 2008, and 2010–2012. We found significant differences in the habitat structural characteristics between the two adjacent wetland habitats that are critical for Reed Parrotbill nest‐site selection. Experimental trials using recently constructed and abandoned Reed Parrotbill nests as ‘artificial nests, quail eggs and predator‐exclusion measures, revealed that tidal mudflat crab (Helice tientsinensis) was the primary cause of Reed Parrotbill egg predation in tidal reed‐bed habitat. Annual predation rates of real nests from inland reed‐bed habitat varied from 35% to 68%, and predation rates of artificial nests were much lower than those from real nests. Pitfall sampling revealed that the abundance of tidal mudflat crabs was significantly higher in tidal reed‐bed habitat. Our data suggested that Reed Parrotbills breeding in tidal reed‐bed habitats may be highly vulnerable due to extremely high rates of nest predation (up to 100%), caused primarily by the high density of tidal mudflat crabs. The incongruence between nest‐site habitat preference and nest survival indicated an ecological trap scenario, which requires further studies on its proximate and ultimate causes as well as the development of effective conservation management for the Reed Parrotbill.

Stress and success: Individual differences in the glucocorticoid stress response predict behavior and reproductive success under high predation risk

A fundamental element of how vertebrates respond to stressors is by rapidly elevating circulating glucocorticoid hormones. Individual variation in the magnitude of the glucocorticoid stress response has been linked with reproductive success and survival. But while the adaptive value of this response is believed to stem in part from changes in the expression of hormone-mediated behaviors, it is not clear how the behavior of stronger and weaker glucocorticoid responders differs during reproduction, or during exposure to ecologically relevant stressors. Here we report that in a population of barn swallows (Hirundo rustica erythrogaster) experiencing high rates of nest predation, circulating levels of corticosterone (the primary avian glucocorticoid) during exposure to a standardized stressor predict aspects of subsequent behavior and fitness. Individuals that mounted a stronger corticosterone stress response during the early reproductive period did not differ in clutch size, but fledged fewer offspring. Parents with higher stress-induced corticosterone during the early reproductive period later provisioned their nestlings at lower rates. Additionally, in the presence of a model predator stress-induced corticosterone was positively associated with the latency to return to the nest, but only among birds that were observed to return. Model comparisons revealed that stress-induced hormones were better predictors of the behavioral and fitness effects of exposure to transient, ecologically relevant stressors than baseline corticosterone. These findings are consistent with functional links between individual variation in the hormonal and behavioral response to stressors. If such links occur, then selection on the heritable components of the corticosterone stress response could promote adaptation to novel environments or predation regimes.

Immune-related effects from predation risk in Neotropical blue-black grassquits (Volatinia jacarina)

Predation is a major force shaping natural history traits of birds because of their vulnerability during nesting and higher visibility during diurnal activities. For most birds in the Neotropics, predation is the major cause of nest failure due to the region's high diversity and abundance of predators. The blue-black grassquit (Volatinia jacarina), similarly to other small passerines in the savanna region of central Brazil, suffers extremely high rates of nest predation. Additionally, males may be particularly vulnerable to predators since they are very conspicuous when executing courtship displays. We assessed some of the non-lethal costs of predation risk on this species by comparing physiological and morphological parameters of birds exposed to predator vocalizations with that of control subjects exposed to non-predator vocalizations. Birds exposed to the predator vocalizations exhibited an immune-related reaction (changes in their H/L ratio), but no changes were observed in other biological parameters measured.This article is part of a Special Issue entitled: Neotropical Behaviour.

Intensive nest predation by crabs produces source–sink dynamics in hosts and parasites

Nest predation is a common cause of reproductive failure. Here, we show for the first time unusually high rates of nest predation on eggs and chicks in nests of the Oriental Reed Warbler Acrocephalus orientalis and the brood parasitic Common Cuckoo Cuculus canorus caused by mudflat crabs Chiromantes dehaani. Crabs and the Common Cuckoo greatly reduce reproductive success of hosts at a site in coastal habitat, but only Common Cuckoos did so at an inland habitat. Thus, the parasitic Common Cuckoo suffered an indirect high predation cost by using bird species affected by crabs as hosts. The difference in the relationship between mudflat crabs, cuckoos and hosts between these two habitats can be explained by the source–sink dynamics of an ecological trap. The coastal habitats constitute sink populations for both host and brood parasite, while inland habitats with cuckoos only constitute sink populations for hosts. Because the population densities of both hosts and parasites are similar in the two kinds of habitats, these similarities might be maintained by immigration from source populations such as those without mudflat crabs and Common Cuckoos, respectively.

Snowy plover nest site selection, spatial patterning, and temperatures in the Southern High Plains of Texas

AbstractSnowy plover (Charadrius nivosus) populations have declined throughout their range, in part because of habitat degradation and poor nest success, making information regarding regionally specific nest site selection and spatial patterns important when considering habitat conservation and management guidelines. We determined nest site selection characteristics (n = 180) and examined spatial patterns (n = 215) of snowy plover nests in saline lakes in the Southern High Plains (SHP) of Texas. At 104 nests, we examined the influence of substrate type on nest temperatures and heat mitigation. Snowy plover nests were more likely to be found near an object, on pebble substrate, and with fewer plants than random sites. High use areas were generally located in areas with pebble substrate and on human‐made or natural islands, berms, and peninsulas. Overall, nests placed on pebble substrate had lower temperatures during the day than nests placed on sand substrates. Nest placement on pebble substrate may be valuable to nesting snowy plovers, providing thermal advantages to incubating adults and depressing potentially high nest predation rates. Management guidelines for this region should emphasize the importance of addressing key elements of snowy plover nesting habitat including the presence of pebble substrate and reducing vegetation encroachment. © 2012 The Wildlife Society.

Increased nest defence of upland‐nesting ducks in response to experimentally reduced risk of nest predation

Parent birds should take greater risks defending nests that have a higher probability of success. Given high rates of mammalian nest predation, therefore, parents should risk more for nests in areas with a lower risk of mammalian predation. We tested this hypothesis using nest defence data from over 1300 nests of six species of dabbling ducks studied in an area where predation risk had been reduced through removal of mammalian predators. When predator removal reduced nest predation, the ducks increased risk taking as predicted. Also as predicted, risk taking varied inversely with body size, an index of annual survival, among species. For ducks to vary nest defence in response to variation in predation risk they must be able to assess the risk of nest predation. Because ducks modified nest defence in the breeding season immediately following predator removal, ducks may be able to assess predator abundance indirectly (e.g. by UV reflection from urine) rather than by seeing or interacting directly with the predators.

Consequences of using Conspecific Attraction in Avian Conservation: A Case Study of Endangered Colonial Waterbirds

Through the use of conspecific models and vocalizations, populations of conservation concern can be established in locations where limiting factors may be controlled or mitigated, assuming managers can both identify and create high-quality locations. From 2003 to 2008, conspecific attraction was used to establish populations of the state-endangered Forster's Tern (Sterna forsteri) in northeastern Illinois, USA. In 2009 and 2010, similar techniques were used with the federally-threatened Least Tern, (Stemula antillarum) near the confluence of the Missouri and Mississippi Rivers in Missouri, USA. At both locations, managers attempted to control factors that may limit tern reproductive success. While in most cases nesting populations were established, in some cases resulting in the greatest documented reproductive success in the region for decades, nest predation the year after the colonies were established was significantly higher than in the year the colony was established. The establishment of colonies attracted a variety of predators, some of which gained access to the colonies and predated tern nests. Conspecific attraction behavior may be a strategy used by birds to stay “one step ahead” of nest predators, and the repeated use of conspecific attraction by managers may result in individuals nesting at a site with high rates of nest predation. As a conservation tool, conspecific attraction should only be used in situations where nest predators can be effectively controlled.