Nest Failure Research Articles

Personality and density affect nest defence and nest survival in the great tit

Recent studies suggest that individual variation in behaviour of prey individuals may cause distinctive responses to nest predators and cooperation with conspecifics. We assessed individual differences during a novel object test and whether these responses were related to nest failure and survival of females during incubation. We additionally carried out experimental trials in natural field conditions using a stuffed pine marten, a principal nest predator, to test for a relationship between neophobia and mobbing predators. Our results show that antipredator responses of breeding great tits are dependent on their personality and personality type of neighbouring conspecifics. We found that neophilic individuals (those that rapidly resumed feeding of nestlings in the presence of a novel object) have an advantage over neophobic individuals (those that slowly resumed feeding of nestlings in the presence of a novel object) in their reproductive success, as measured in numbers of successful nests and of females that survived. Furthermore, neophilic-neophilic pairs exhibited stronger antipredator mobbing responses than neophobic-neophobic pairs. Results show that consistent individual differences in response against novel objects and antipredator behaviour are related, and that these responses are important predictors of nest failure in breeding great tits.

Combining site occupancy, breeding population sizes and reproductive success to calculate time-averaged reproductive output of different habitat types: an application to Tricolored Blackbirds.

In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor) has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005–2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent investigation. The method we employ should be useful in other metapopulation studies for calculating time-averaged reproductive output for different sites.

Snake predation on North American bird nests: culprits, patterns and future directions

Predation is the leading cause of nest failure for most birds. Thus, for ornithologists interested in the causes and consequences of variation in nest success, knowing the identity and understanding the behavior of dominant nest predators is likely to be important. Video documentation of nests has shown that snakes are frequent predators. Here we reviewed 53 North American studies that used nest cameras and used these data to identify broad patterns in snake predation. Snakes accounted for 26% (range: 0–90%) of recorded predation events, with values exceeding 35% in a third of studies. Snakes were more frequent nest predators at lower latitudes and less frequent in forested habitat relative to other nest predators. Although 12 species of snakes have been identified as nest predators, ratsnakes Elaphe obsoleta, corn snakes E. guttata and fox snakes E. vulpina were the most frequent, accounting for > 70% of all recorded nest predation events by snakes and have been documented preying on nests in 30–65% of studies conducted within their geographic ranges. Endotherm‐specialist snakes (Elaphe and Pituophis genera) were more likely to depredate nests in forests and the canopy relative to other snakes, due to their affinity for edge habitat. Predation by only ratsnakes and corn snakes was predominantly nocturnal and only ratsnakes were more likely to prey on nests during the nestling stage. Snakes were not identified to species in over 30% of predation events, underlining the need for more complete reporting of results. A review of research to date suggests the best approach to investigating factors that bring snakes and nests into contact involves combining nesting studies with radio tracking of locally important snake nest predators.

Artificial Nests Identify Possible Nest Predators of Eastern Wild Turkeys

Poor nest survival is a critical limiting factor in the recruitment of wild birds. Nest predation is often cited as one of the main causes of nest failure, especially for ground-nesting species. We monitored artificial Meleagris gallopavo silvestris (Eastern Wild Turkey) nests, using time-lapse and motion-sensitive trail cameras to determine which predators were likely to be responsible for preying on Wild Turkey nests in the Pineywoods of East Texas. Sixty-one percent of all artificial nests were preyed upon. Corvus brachyrhynchos (American Crow) preyed on 48% of artificial nests and Procyon lotor (Raccoon) preyed on 35%. There was a seasonal increase in the number of artificial nests preyed upon from spring to summer. Mammalian mesopredators, Raccoon and Didelphis virginiana (Opossum), were primarily responsible for this increase, suggesting an increase in search effort by mesopredators that coincided with increased dietary diversity in a period of reduced prey resources. Predators other than mesopredators—American Crows, Picoides sp. (woodpeckers), Dasypus novemcinctus (Nine-banded Armadillo), and snakes—were responsible for 53% of all predation on the artificial Wild Turkey nests, with American Crows being the most important of these. After nest deployment, American Crows located and preyed on artificial nests more quickly than other nest predators. We suggest video monitoring of natural Eastern Wild Turkey nests to confirm the identity of nest predators.

Effects of Grazing on Nesting of the Oriental Pratincole (Glareola maldivarum) in Bueng Boraphet Wetland, Thailand

Livestock grazing may negatively impact bird nesting in wetland habitats. This study evaluated the effect of grazing on the nests of the Oriental pratincole (Glareola maldivarum) along the grassland of a wetland at six study sites with different densities of grazing cattle and buffalo. Species richness, density, cover, and height of vegetation in the study areas were different (P < 0.05). The density of cattle and buffalo at the various sites affected vegetation composition and amount, which in turn influenced bird nest density. The estimated trampling rates, number of fledglings, and number of trampled eggs were different among study sites (P < 0.05). The density of cattle and buffalo has an influence on nest failure rates. The factors that influenced the mortality rates of the Oriental pratincole were trampling and unhatched eggs. Only 48.5% of the nests were successful at sites where cattle and buffalo continuously grazed in the grasslands at high densities. Thus, increases in the density of cattle and buffalo will reduce the number of nests of the Oriental pratincole, which may result in a reduction of the overall population in the future.

Insights into life history theory: a brood size manipulation on a southern hemisphere species, Tachycineta leucorrhoa, reveals a fast pace of life

Life history traits exhibit substantial geographical variation associated with the pace of life. Species with a slow pace are expected to invest more in their future/residual reproductive value and are more common at tropical latitudes, whereas species from high latitudes, with a faster pace, are expected to prioritize the current reproductive effort. Most evidence supporting this pattern comes from studies conducted in tropical and north temperate species; very little is known about patterns in southern South American species. Here, we describe the life history of a southern swallow Tachycineta leucorrhoa and use an experimental approach to test their breeding strategy over four breeding seasons. We manipulated brood size for 105 nests of white‐rumped swallows to measure whether costs of reproduction were borne by adults or nestlings as alternative selection strategies towards maintaining residual or current reproductive value. Adults increased their feeding effort in enlarged broods, at least enough to maintain nestlings’ development/growth. In addition, adults decreased the number of visits to the nest (without having a negative effect on nestlings) in reduced broods. We did not detect differences in fledging success among treatments, suggesting there were no differences in nestlings’ survival. However, enlarged broods more frequently incurred in complete nest failure, suggesting only some adults were able to cope with increased costs of reproduction. We conclude this species is characterized by a fast pace of life similar to their northern congeners and less like its tropical ones. This is one of the first studies to use an experimental approach to test a life history hypothesis of pace of life using data from a southern South American species. We encourage researches to include southern species when evaluating latitudinal variations as we still do not have enough evidence to assume all southern subtropical species are indeed similar to tropical ones.

Daily survival rate for nests of Black Skimmers from a core breeding area of the southeastern USA

Little is known about the reproductive success of Black Skimmers (Rynchops niger) throughout the southeastern USA where availability of undisturbed beaches for nesting is limited. Daily survival rates (DSR) of nests were examined at three nesting sites in Cape Romain National Wildlife Refuge (CRNWR), South Carolina, USA, 2009–2010. The percent of successful nests (n = 346 nests) ranged from 42–69% among colony sites when data were pooled across both years. The DSR of nests was primarily related to colony site, predation risk, height of high tide, and clutch size. Predation and overwash were the principal causes of identifiable nest loss, each accounting for ∼33% of nest failures during the two study years. Because of the challenges of resighting skimmer chicks, we were not able to measure chick survival effectively and therefore accurate measures of productivity remain elusive. High variability in nest success among sites within close proximity to each other (<20 km) suggests factors at local scales such as disturbance, predation, and overwash events strongly influenced nest success of Black Skimmers during these 2 years as opposed to more region-wide stressors such as tropical storms or food availability. Although time-intensive techniques to control predators do exist, management options to limit flooding and overwash are far more limited. Conservation of Black Skimmers in the southeastern USA would benefit from coordinated, multi-state efforts to measure nest and chick survival.

Nest predators of a woodland bird community in south-east Australia

Nest predation is the most common source of nest failure in most passerines, yet the identity of the predators is generally poorly known. Recent advances in surveillance cameras have made the ident...

Does no-till soybean farming provide any benefits for birds?

Nesting success and avian communities were compared between tilled and no-till soybean fields in Illinois. No-till had greater densities of birds than tilled fields, and the overall community in no-till was of greater conservation value due to more grassland birds using no-till compared with tilled fields. Nesting density was greater in no-till (4.5 nests/100ha) than in tilled (1.6) fields. The most common nesting species were American robins, vesper sparrows, and mourning doves. Nest success, as estimated from daily survival rates, was 19.4% in no-till and 9.4% in tilled fields. Predation was the main cause of nest failure, but 24.4% of failures were caused by farm machinery. The authors propose that the previous year's crop residue and greater abundance of weedy plants in no-till resulted in increased nesting and foraging activity in no-till and greater nest success because of increased opportunity to conceal nests in no-till compared to tilled fields. No-till provides greater benefits to birds than tilled fields, and the large amount of acreage in row crops dictates that we understand the contribution of no-till fields to grassland bird populations.

Hard times in the city - attractive nest sites but insufficient food supply lead to low reproduction rates in a bird of prey.

IntroductionUrbanization is a global phenomenon that is encroaching on natural habitats and decreasing biodiversity, although it is creating new habitats for some species. The Eurasian kestrel (Falco tinnunculus) is frequently associated with urbanized landscapes but it is unclear what lies behind the high densities of kestrels in the urban environment.ResultsOccupied nest sites in the city of Vienna, Austria were investigated along a gradient of urbanization (percentage of land covered by buildings or used by traffic). Field surveys determined the abundance of potential prey (birds and rodents) and the results were compared to the birds’ diets. A number of breeding parameters were recorded over the course of three years. The majority of kestrels breed in semi-natural cavities in historic buildings. Nearest neighbour distances (NND) were smallest and reproductive success lowest in the city centre. Abundance of potential prey was not found to relate to the degree of urbanization but there was a significant shift in the birds’ diets from a heavy reliance on rodents in the outskirts of the city to feeding more on small birds in the centre. The use of urban habitats was associated with higher nest failure, partly associated with predation and nest desertion, and with significantly lower hatching rates and smaller fledged broods.ConclusionsHigh breeding densities in urban habitats do not necessarily correlate with high habitat quality. The high density of kestrel nests in the city centre is probably due to the ready availability of breeding cavities. Highly urbanized areas in Vienna are associated with unexpected costs for the city dwelling-raptor, in terms both of prey availability and of reproductive success. The kestrel appears to be exploiting the urban environment but given the poor reproductive performance of urban kestrels it is likely that the species is falling into an ecological trap.

Veery (Catharus fuscescens) Nest Architecture and the Use of Alien Plant Parts

The use and potential consequence of alien plant parts in the construction of open-cup leaf nests by Nearctic-breeding forest songbirds has not been investigated. We dissected 19 leaf nests constructed by Veeries (Catharus fuscescens) over two breeding seasons in a temperate broadleaf forest infested with alien plants. Our objectives were: (1) confirm the architectural approach used by Veeries to construct nests, (2) determine if Veeries used alien plant parts in nest construction, (3) determine if nest success was related to the use of alien material, (4) determine the use of alien plants relative to native plants, and (5) test for an association of alien plant mass with the progression of the nesting season. Our results showed that Veeries constructed three separate nest layers: (1) a platform for support, (2) an inner cup, and (3) nest lining. Veeries incorporated parts from six alien plant species in their nests representing 22% of the 27 species used. All nests contained alien plant parts but use differed among the three layers. In particular the use of stems of Alliaria petiolata and Rosa multiflora, two alien species, appeared to provide important structural support in the nest's outer layers. Although our sample size was small, we found no relationship between the use of alien plant parts and nest failure suggesting use of alien plant material does not have negative effects on productivity. We caution that sudden large-scale restoration efforts, which remove the alien forest plant species used in nest construction prior to the recovery of comparable native species, may result in the temporary reduction of materials available to birds for nest construction.

Nest survival and breeding biology of the Puerto Rican Bullfinch (Loxigilla portoricensis) in southwestern Puerto Rico

Abstract Breeding biology information, including nest survival estimates, are lacking for many nesting species in Puerto Rico. We studied the endemic Puerto Rican Bullfinch (Loxigilla portoricensis), and modeled daily nest survival to better understand the effects of several factors on daily nest survival. In 2009 and 2010 we monitored 37 bullfinch nests at two sites in southwestern Puerto Rico. Predation was the most important cause of nest failure. Ten nest survival models received approximately equal support. No temporal trends in nest survival were supported over others. Results suggested that available fruit is important for successful nesting, increased precipitation is related to higher nest survival, nest survival varied by site, and increased nest height is related to lower nest survival in bullfinches. Under the top model, daily nest survival rates for each site and nest stage ranged from 0.83–0.86% in 2009 and 0.80–0.93% in 2010. This information on nest survival and factors that influence it i...

Informed renesting decisions: the effect of nest predation risk

Animals should cue on information that predicts reproductive success. After failure of an initial reproductive attempt, decisions on whether or not to initiate a second reproductive attempt may be affected by individual experience and social information. If the prospects of breeding success are poor, long-lived animals in particular should not invest in current reproductive success (CRS) in case it generates costs to future reproductive success (FRS). In birds, predation risk experienced during breeding may provide a cue for renesting success. Species having a high FRS potential should be flexible and take predation risk into account in their renesting decisions. We tested this prediction using breeding data of a long-lived wader, the southern dunlin Calidris alpina schinzii. As predicted, dunlin cued on predation risk information acquired from direct experience of nest failure due to predation and ambient nest predation risk. While the overall renesting rate was low (34.5%), the early season renesting rate was high but declined with season, indicating probable temporal changes in the costs and benefits of renesting. We develop a conceptual cost-benefit model to describe the effects of the phase and the length of breeding season on predation risk responses in renesting. We suggest that species investing in FRS should not continue breeding in short breeding seasons in response to predation risk but without time constraints, their response should be similar to species investing in CRS, e.g. within-season dispersal and increased nest concealment.

The demography of Yellow Wagtails Motacilla flava on abandoned fields in northern European Russia

Capsule Apparent survival rates of Yellow Wagtails breeding in abandoned fields in Russia are determined by previous breeding success.Aims To examine apparent survival and its link to previous breeding success in Yellow Wagtails breeding in abandoned fields in the Vologda region, northern European Russia.Methods We ringed and measured apparent survival of Yellow Wagtails at two abandoned agricultural sites over eight years (2005–2012). We modelled the impact of age, nest stage, and time of season on daily nest survival rates.Results Predation was the main cause of nest failure. Nest daily survival rate was highest at the beginning of the breeding season. Overall nest survival probability was 0.40 ± 0.02. Adult apparent survival after successful breeding was 0.42 ± 0.06 and after unsuccessful breeding this was 0.13 ± 0.06.Conclusion Reproductive success can be regarded as the crucial demographic parameter of the local Yellow Wagtail population in northern European Russia. Apparent survival after successful breeding is significantly higher than after unsuccessful breeding, because unsuccessful breeders probably move to new breeding sites the following year. High adult survival may be particularly important to Yellow Wagtail population dynamics in the study region, because second breeding attempts are apparently unusual.

Effects of nest success and mate fidelity on breeding dispersal in a population of Snowy PloversCharadrius nivosus

SummaryBreeding dispersal subsequent to nest failure is hypothesised to be a behavioural response to danger posed by nest predators. We used histories and locations of male and female Snowy PloverCharadrius nivosusnests in northern California over a 10-year period to examine effects of nest fate, mate fidelity, residency, predator exclosures, and age on dispersal distance. Within years, females moved a median distance of 2.2 km after changing mates; males moved a median of 0.9 km. Between years, plovers moved the shortest distances when they retained a mate from the prior year and were successful in hatching eggs (males = 0.2 km, females = 0.3 km). Both females (13.0 km) and males (2.6 km) dispersed farther when mate change coincided with nest failure in the prior year. The observation that most plovers did not disperse far enough to move away from sites where predators are abundant and have strong effects on plover reproductive success suggests that effective predator management will be challenging.

Greater Sage-Grouse Nest Predators in the Virginia Mountains of Northwestern Nevada

Abstract Greater sage-grouse Centrocercus urophasianus, hereafter sage-grouse, populations have declined across their range due to the loss, degradation, and fragmentation of habitat. Habitat alterations can lead not only to vegetative changes but also to shifts in animal behavior and predator composition that may influence population vital rates, such as nest success. For example, common ravens Corvus corax are sage-grouse nest predators, and common raven abundance is positively associated with human-caused habitat alterations. Because nest success is a central component to sage-grouse population persistence, research that identifies factors influencing nest success will better inform conservation efforts. We used videography to unequivocally identify sage-grouse nest predators within the Virginia Mountains of northwestern Nevada, USA, from 2009 to 2011 and used maximum likelihood to calculate daily probability of nest survival. In the Virginia Mountains, fires, energy exploration, and other anthropogenic activities have altered historic sage-grouse habitat. We monitored 71 sage-grouse nests during the study, placing video cameras at 39 nests. Cumulative nest survival for all nests was 22.4% (95% CI, 13.0–33.4%), a survival rate that was significantly lower than other published results for sage-grouse in the Great Basin. Depredation was the primary cause for nest failure in our study (82.5%), and common ravens were the most frequent sage-grouse nest predator, accounting for 46.7% of nest depredations. We also successfully documented a suite of mammalian and reptilian species depredating sage-grouse nests, including some predators never previously confirmed in the literature to be sage-grouse nest predators (i.e., bobcats Lynx rufus and long-tailed weasels Mephitis frenata). Within the high elevation, disturbed habitat of the Virginia Mountains, low sage-grouse nest success may be limiting sage-grouse population growth. These results suggest that management actions that restore habitat in the Virginia Mountains and decrease anthropogenic subsidies of ravens will benefit sage-grouse.

Experimental test of a conservation intervention for a highly threatened waterbird

Human exploitation and disturbance often threaten nesting wildlife. Nest guarding, a technique that employs local people to prevent such interference, is being applied to an increasing number of species and sites, particularly in South-East Asia. Although research has begun to assess the cost-effectiveness of nest guarding, case–control studies are rare and the circumstances in which the schemes are most useful remain unclear. We experimentally tested the effect of nest guarding for the critically endangered white-shouldered ibis (Pseudibis davisoni), a species exploited opportunistically for food and now largely confined to dry forests in Cambodia. We randomly applied guarded and unguarded (control) treatments to 24 and 25 nests, respectively, at a single site over 2 years. Nest guarding had no detectable effect on nest success, with an overall probability of nest success of 0.63–0.86 at guarded and 0.55–0.82 at unguarded nests. Nest monitoring across 4 study sites over 3 breeding seasons found a combination of natural predation, weather, and anthropogenic activities (robbery and vandalism) responsible for nest failure, although causes of failure remained unknown at 58% of nests. Nest guarding itself increased nest destruction at 1 site, indicating that this intervention needs cautious implementation if only a small proportion of the local community gains benefit. Comparison with other studies suggests that nest guarding effectiveness may be context-specific and differ between species that are exploited opportunistically, such as white-shouldered ibis, and those routinely targeted for trade. © 2013 The Wildlife Society.

Temperatures in Excess of Critical Thresholds Threaten Nestling Growth and Survival in A Rapidly-Warming Arid Savanna: A Study of Common Fiscals

Frequency, duration, and intensity of hot-weather events are all predicted to increase with climate warming. Despite this, mechanisms by which temperature increases affect individual fitness and drive population-level changes are poorly understood. We investigated the link between daily maximum air temperature (tmax) and breeding success of Kalahari common fiscals (Lanius collaris) in terms of the daily effect on nestling body-mass gain, and the cumulative effect on size and age of fledglings. High tmax reduced mass gain of younger, but not older nestlings and average nestling-period tmax did not affect fledgling size. Instead, the frequency with which tmax exceeded critical thresholds (tcrits) significantly reduced fledging body mass (tcrit = 33°C) and tarsus length (tcrit = 37°C), as well as delaying fledging (tcrit = 35°C). Nest failure risk was 4.2% per day therefore delays reduced fledging probability. Smaller size at fledging often correlates with reduced lifetime fitness and might also underlie documented adult body-size reductions in desert birds in relation to climate warming. Temperature thresholds above which organisms incur fitness costs are probably common, as physiological responses to temperature are non-linear. Understanding the shape of the relationship between temperature and fitness has implications for our ability to predict species’ responses to climate change.

Invasive smallmouth bass (Micropterus dolomieu): history, impacts, and control

In this review, we (i) describe smallmouth bass (Micropterus dolomieu Lacepede, 1802) invasions past, present, and future; (ii) summarize the impact that this species can have on native communities; and (iii) describe and discuss various options for control. M. dolomieu are invasive throughout much of the United States, southern portions of Canada, and in countries in Europe, Asia, and Africa. Historically, this species spread via stocking programs intended to improve sport fisheries. Currently, their spread is facilitated by anglers and global climate change. Models predict that M. dolomieu will continue to spread with consequences for native prey fish, sport fish, and food webs through predation, competition, and hybridization. Effective control methods are necessary to mitigate these impacts. Options for M. dolomieu control include biological control, chemical control, environmental manipulation, and physical removal. However, our review of the literature suggests that only a handful of the possible control options have been explored (usually in isolation and with limited success), and that there is a clear need for focused research and informed management. For example, our elasticity analysis of published M. dolomieu matrix population models suggests that M. dolomieu control will be most effective when it targets eggs, larvae, and juveniles. We recommend targeting these life stages by using nest failure as part of an adaptive and integrated pest management approaches that incorporate existing and emerging technologies. However, we also emphasize that M. dolomieu control, where necessary and possible, is more likely to take the form of suppression rather than permanent eradication. Therefore, we also recommend efforts to prevent M. dolomieu (re)introduction.

Hatching Success and Nest Site Characteristics of Black Skimmer (Rynchops niger) on the Isles Dernieres Barrier Island Refuge, Louisiana

Abstract. Barrier islands provide numerous ecosystem functions and services, including critical breeding habitat for many waterbird species. Louisiana's barrier islands are experiencing rapid land loss and habitat degradation. Restoration of barrier islands has become a high priority in Louisiana and barrier island degradation has increased waterbird reliance on restored dredge material islands. To improve restoration and management of barrier islands, we investigated the hatching success of Black Skimmer (Rynchops niger) and determined important habitat characteristics for their hatching success. Nest monitoring and nest habitat characteristics were measured at breeding colonies on the Isles Dernieres Barrier Island Refuge, Louisiana, in 2009 and 2010. Hatching success varied greatly for Black Skimmers (1–84%). Predation, flooding, and competition were the three main causes of nest failure. Habitat modeling identified nest elevation relative to the high-tide line and distance to high-tide line as importa...