Natural Nests Research Articles

The role and significance of stingless bees (Hymenoptera: Apiformes: Meliponini) in the natural environment

Abstract This article refers to the biology and ecology of stingless bees (Meliponini), living in tropical and subtropical areas. Similar to honey bees (Apis mellifera), stingless bees (Meliponini) belong to the category of proper social insects and are at the highest level of social development. This group of insects comprises about 500 species and they are the most common bees pollinating the native plants in many tropical areas. Families of stingless bees are usually quite numerous, reaching up to 100,000 individuals. They are characterised by polymorphism, age polyethism and perennialism. This article presents the structural complexity of natural nesting of these tropical insects and their ability to settle in artificial nest traps. The main significance of stingless bees for humans is their role in the natural environment as pollinators, which is an essential factor influencing biodiversity.

Observations on the use of dummy nests by fledgling Worthington's Marsh Wrens (Cistothorus palustris griseus)

For decades, researchers have attempted to understand why some avian species expend energy building nests that are not explicitly used for breeding (i.e., dummy nests). Most work has focused on whether dummy nests serve as indicators of male fitness or as decoys for confusing nest predators. Anecdotal observations suggest that dummy nests may also be used as temporary shelters for adults and fledglings, but the frequency with which this occurs is unknown. While trapping Cistothorus palustris griseus (Worthington's Marsh Wren) nestlings as part of a larger study in the saltmarshes of northeast Florida, we observed newly fledged young using dummy nests on 8 of 45 occasions (18%) during which one or more nestlings were absent from the natal nest. It is likely that the actual frequency of dummy nest use by fledglings is greater than what we observed because our efforts to locate fledglings were infrequent and opportunistic, and because depredation may account for a significant proportion of the occasions when no fledglings were found. Dummy nests may play a larger role in post-fledging survival than previously thought and warrant further investigation.

Population and colony structure of an ant with territorial males, Cardiocondyla venustula

BackgroundMany species of social insects have large-scale mating and dispersal flights and their populations are therefore often relatively homogenous. In contrast, dispersal on the wing appears to be uncommon in most species of the ant genus Cardiocondyla, because its males are wingless and the winged queens mate in their natal nests before dispersing on foot. Here we examine the population structure of C. venustula from South Africa. This species is of particular interest for the analysis of life history evolution in Cardiocondyla, as it occupies a phylogenetic position between tropical species with multi-queen (polygynous) colonies and fighting males and a Palearctic clade with single-queen colonies and mutually peaceful males. Males of C. venustula exhibit an intermediate strategy between lethal fighting and complete tolerance – they mostly engage in non-lethal fights and defend small territories inside their natal nests. We investigated how this reproductive behavior influences colony and population structure by analyzing samples on two geographic scales in South Africa: a small 40 × 40m2 plot and a larger area with distances up to 5 km between sampling sites in Rietvlei Nature Reserve near Pretoria.ResultsColonies were found to be facultatively polygynous and queens appear to mate only with a single male. The extraordinarily high inbreeding coefficient suggests regular sib-mating. Budding by workers and young queens is the predominant mode of colony-founding and leads to high population viscosity. In addition, some queens appear to found colonies independently or through adoption into foreign nests.ConclusionWhile C. venustula resembles tropical Cardiocondyla in queen number and mating frequency, it differs by the absence of winged disperser males. Dispersal by solitary, mated queens on foot or by short flights and their adoption by alien colonies might promote gene flow between colonies and counteract prolonged inbreeding. The abundance of suitable habitat and the high density of nests facilitate the spread of this species by budding and together with the apparent resistance against inbreeding make it a highly successful pioneer species and invader of degraded and man-made habitats.

Queen Dominance May Reduce Worker Mushroom Body Size in a Social Bee.

The mushroom body (MB) is an area of the insect brain involved in learning, memory, and sensory integration. Here, we used the sweat bee Megalopta genalis (Halictidae) to test for differences between queens and workers in the volume of the MB calyces. We used confocal microscopy to measure the volume of the whole brain, MB calyces, optic lobes, and antennal lobes of queens and workers. Queens had larger brains, larger MB calyces, and a larger MB calyces:whole brain ratio than workers, suggesting an effect of social dominance in brain development. This could result from social interactions leading to smaller worker MBs, or larger queen MBs. It could also result from other factors, such as differences in age or sensory experience. To test these explanations, we next compared queens and workers to other groups. We compared newly emerged bees, bees reared in isolation for 10days, bees initiating new observation nests, and bees initiating new natural nests collected from the field to queens and workers. Queens did not differ from these other groups. We suggest that the effects of queen dominance over workers, rather than differences in age, experience, or reproductive status, are responsible for the queen-worker differences we observed. Worker MB development may be affected by queen aggression directly and/or manipulation of larval nutrition, which is provisioned by the queen. We found no consistent differences in the size of antennal lobes or optic lobes associated with differences in age, experience, reproductive status, or social caste.

Multilayer, locality aware, telecommunication network deployment algorithm

Purpose – In this paper we propose an iterative approach for the deployment of rural telecommunication networks.
 Methodology/approach/design – This approach relies heavily on the concept of locality, prioritizing small ‘cells’ with a considerable population density, and exploits the natural nesting of the distribution of rural communities, focusing in communities which are populous enough to justify the investment required to provide them with connectivity, and whose sheer size promotes the formation of ‘satellite’ communities that could be benefited from the initial investment at a marginal expense. For this approach, the concept of ‘cells’ is paramount, which are constructed iteratively based on the contour of a Voronoi tessellation centered on the community of interest. Once the focal community has been ‘connected’ with network of the previous layer, the process is repeated with less populous communities at each stage until a coverage threshold has been reached. One of the main contributions of this methodology is that it makes every calculation based on ‘street distance’ instead of Euclidean, giving a more realistic approximate of the length of the network and hence the amount of the investment. To test our results, we ran our experiments on two segregated communities in one of the most complicated terrains, due to the mountain chains, in the state of Chiapas, Mexico.
 Findings – The results suggest that the use of ‘street distance’ and a local approach leads to the deployment of a remarkably different network than the standard methodology would imply.
 Practical implications – The results of this paper might lead to a significant reduction in the costs associated with these kinds of projects and therefore make the democratization of connectivity a reality. In order to make our results reproducible, we make all our code open and publicly available on GitHub.

Laju Penetasan Telur Penyu Dengan Substrat Yang Berbeda Di Kabupaten Gorontalo Utara

The aim of the study was to determine the rate of hatching of turtle eggs with different substrates in North Gorontalo Regency. The research method is an experiment with a Complete Randomized Design (CRD), which is 3 treatments and 3 repetitions obtained from direct observations in the field will be analyzed quantitatively and qualitatively. The treatment consists of Treatment A (Control ie sand from natural nests), Treatment B (coarse sand with a diameter of 0.50-1.00 mm) and Treatment C (fine sand with a diameter of 0.10-0.21 mm. Based on the results of the research on turtle egg hatching with different substrates in the District of Monano, North Gorontalo Regency, it was shown that the average hatching of turtle eggs was the highest at treatment B which was 78%, then treatment A which was 50% and the lowest was in treatment C namely 39%.

Multidimension‐Controllable Synthesis of Ant Nest‐Structural Electrode Materials with Unique 3D Hierarchical Porous Features toward Electrochemical Applications

AbstractHierarchical porous materials (HPM) have been widely used to enhance electrochemical performance in different fields of application, since their porous structures benefit electrolyte infiltration and ion diffusion. However, the realization of multidimension‐controllable synthesis of HPM, including material category, material components, supporting substrates, as well as pore sizes/distributions, is still a huge challenge. Herein, a novel concept is proposed, for the first time, on the geometry structure of HPM bioinspired by natural ant nests, which features 3D interlaced and well‐interconnected porous structures. Moreover, a facile and universal approach is developed to the multidimension‐controllable synthesis of ant nest‐structural HPM. Further investigation shows that the in situ construction of carbon‐based ant nests onto porous current collectors to fabricate the integrated electrode for supercapacitors could induce nearly 70% and 45% enhancement on the specific capacitance compared to the common powder and freestanding materials, respectively. Moreover, this synthesis route can be facilely extended to obtain the ant nest‐structural CuOx, which exhibits fivefold enhancement in sensitivity for glucose detection. Such biomimetic hierarchical porous architectures are of great significance in the field of electrochemical applications.

A Scientific Note on a Stingless Bee Hive Model for Ecological and Behavioral Studies and for Environmental Education

Stingless bees (Apidae; Meliponini) occupy a great diversity of habitats in tropical and subtropical regions. They are eusocial and live in sessile colonies. Most meliponini species build nests in pre-existing cavities, such as tree hollows and stingless bee hive models imitate the conditions of natural nests. However, they are unwieldy for scientific studies, especially those focused on ecological and behavioral characteristics. We developed and tested a hive model that ensures clear visibility of the interior of the hive and facilitates ecological and behavioral studies and for environmental education. It successfully housed ten stingless bee species and one semi-social orchid bee species.

To leave or to stay: direct fitness through natural nest foundation in a primitively eusocial wasp

Dispersing from the natal nest to found new nests is an avenue for gaining direct fitness for workers in some primitively eusocial insects, especially in species with a perennial nesting cycle where males are present throughout the year. Such nest foundation is difficult to study in nature or in small laboratory cages. Hence, we have investigated the dynamics of nest foundation by workers of the primitively eusocial wasp Ropalidia marginata inside closed walk-in cages so that we could locate and observe every event of nest foundation. Starting with nine parent nests we observed the dispersal of female workers that initiated 9 single-foundress and 20 multiple-foundress nests. Wasps congregated outside their parent nests and engaged in dominance–subordinate interactions before initiating multiple foundress nests. The most dominant wasps of such aggregations became queens, and among the others, some joined the new nests as cofoundresses to become workers while the others remained in the parent nests. Solitary foundresses never participated in such off-nest aggregations. Solitary foundresses and future queens of multiple foundress nests engaged in self-feeding behaviour outside their parent nests, a behaviour not performed by wasps that did not initiate new nests. Queens of new nests gained immediate direct fitness. Although the cofoundresses continued to gain only indirect fitness, they are expected to have a higher probability of gaining direct fitness in the future as compared to the corresponding probability in their much larger parent nests. These findings underscore the importance of direct fitness in the evolution of cooperation in primitively eusocial insects.

Anthropogenic nest sites provide warmer incubation environments than natural nest sites in a population of oviparous reptiles near their northern range limit.

Oviposition site choice affects a host of offspring phenotypes and directly impacts maternal fitness. Recent evidence suggests that oviparous reptiles often select nest sites where the landscape has been altered by anthropogenic activity, whereas natural nest sites are less often used. We leverage a long-term study of snapping turtle (Chelydra serpentina) to identify natural nest sites and anthropogenic nest sites and to compare habitat variables among nest site types. Natural and anthropogenic nest sites did not differ in average canopy closure, distance to nearest water, substrate composition, or aspect. However, anthropogenic nest sites had less ground-level vegetation and greater soil brightness, and were 3.3°C warmer than natural nests during incubation. We used the Schoolfield model of poikilotherm development to assess differences in development rate between natural and anthropogenic nests. Because of the difference in temperature, embryos in anthropogenic nests were predicted to have undergone nearly twice as much development as embryos in natural nests during incubation. We outline why the evolution of fast embryonic development rate cannot compensate indefinitely for the low temperature incubation regimes that become increasingly prevalent at northern range margins, thereby underlining why maternal nest site choice of relatively warm anthropogenic sites may help oviparous reptiles persist in thermally constrained environments. Future research should aim to quantify both the thermal benefits of anthropogenic nest sites, as well as associated fitness costs (e.g., increased adult mortality) to elucidate whether anthropogenic disturbance of the landscape can be an ecological trap or serve a net benefit to some reptiles in northern environments.

Does land use change influence predation of bird nests?

AbstractWorldwide, many areas of agricultural land which were once covered with native vegetation have been converted to tree plantations. Such landscape transformation can influence the dynamics of wildlife populations through, for example, altering rates of predation (e.g. predation of nests of birds). Nest predation can influence reproductive success and, in turn, may alter populations by affecting juvenile recruitment. We quantified predation of bird nests in woodland remnants surrounded by two types of land use, grazing farmland and exotic Radiata pine (Pinus radiata) plantation. We also examined differences in predation rates between artificial and natural nests. We found both artificial and natural nests were more susceptible to nest predation in woodland remnants surrounded by a pine plantation than in woodland remnants located within farmland. Our study suggests that higher levels of nest predation may reduce occupancy of woodland remnants by small‐bodied birds over time, including species of conservation concern. This may have been occurred as a result of the conversion of semi‐cleared grazing land to exotic pine plantation.

Predator search image and the dilution effect: When is the best time to nest?

AbstractThe predator search image hypothesis predicts that predators will focus on prey that are abundant and with which they have had success. However, the predator dilution effect hypothesis predicts a decrease in the per capita chance of being depredated with an increasing amount of prey. We evaluated these hypotheses through an artificial nest survival study. We estimated nest survival during both the non-breeding and breeding seasons of 2014 at a restinga (sand-coastalplain) area in southeastern Brazil. We installed 450 artificial nests (cup shaped) in each season and placed a Common quail (Coturnix coturnix) egg in each nest, totaling 900 nests. During the non-breeding season, our nests were the only ones present and thus the predator dilution effect should be absent. We estimated daily survival rate (DSR) using the “Nest Survival” function in the program MARK. We found a decrease in DSR at the middle and end in comparison with the onset of the non-breeding season, which supports the predator search image hypothesis. In comparison with the nonbreeding season, we also found that DSR of artificial nests was lower at the onset and end of the breeding season, but higher in the middle of the breeding season. This pattern matched the higher availability of prey (i.e. natural nests) in the middle of the breeding season in the study site, supporting the dilution effect hypothesis. The survival rate of artificial nests suggests that both the search image and the dilution effect may occur during the breeding season, and that the predator dilution effect masks the predator search image in the middle of the breeding season. Our results expand our understanding regarding the effects of the search image and predator dilution effect hypotheses on nest predation, showing that both are density-dependent and may occur during the breeding season

The effects of weather, group size and type of nest on the timing of egg-laying in the Southern Ground-hornbill Bucorvus leadbeateri

The timing of breeding in birds has important consequences if food availability varies seasonally. Optimal timing of the most energetically demanding stages of breeding to coincide with peaks in food availability can increase breeding success. Early breeding may be challenging for females producing eggs, but generally birds initiating egg-laying early in the breeding season are more likely to succeed. Initiating egg-laying later may be less costly to females, but raising offspring after the peak in food availability becomes challenging. Balancing these costs and benefits is important for the cooperative breeding Southern Ground-hornbill Bucorvus leadbeateri (hereafter ‘Ground-hornbill’), which typically produces only a single clutch of two eggs and fledges a single chick per breeding season. A previous study found that Ground-hornbill groups that lay early in the breeding season are more likely to fledge a chick than later-breeding groups. We investigated factors associated with the timing of breeding such as group size, the type of nest used, rainfall and temperature in a study site supplemented with nest boxes. Ground-hornbills laid eggs from 9 September to 14 November and the average number of days between the first and the last laying date in a season was 48 ± 32 days (range 10–101 days). Larger groups, particularly those using natural nests compared to those using nest boxes, laid later than smaller groups. Egg-laying was delayed under hot, dry spring conditions and laying dates were earlier following above-average spring rainfall.

Harmonic radar tracking reveals random dispersal pattern of bumblebee (Bombus terrestris) queens after hibernation

The dispersal of animals from their birth place has profound effects on the immediate survival and longer-term persistence of populations. Molecular studies have estimated that bumblebee colonies can be established many kilometers from their queens’ natal nest site. However, little is known about when and how queens disperse during their lifespan. One possible life stage when dispersal may occur, is directly after emerging from hibernation. Here, harmonic radar tracking of artificially over-wintered Bombus terrestris queens shows that they spend most of their time resting on the ground with intermittent very short flights (duration and distance). We corroborate these behaviors with observations of wild queen bees, which show similar prolonged resting periods between short flights, indicating that the behavior of our radar-monitored bees was not due to the attachment of transponders nor an artifact of the bees being commercially reared. Radar-monitored flights were not continuously directed away from the origin, suggesting that bees were not intentionally trying to disperse from their artificial emergence site. Flights did not loop back to the origin suggesting bees were not trying to remember or get back to the original release site. Most individuals dispersed from the range of the harmonic radar within less than two days and did not return. Flight directions were not different from a uniform distribution and flight lengths followed an exponential distribution, both suggesting random dispersal. A random walk model based on our observed data estimates a positive net dispersal from the origin over many flights, indicating a biased random dispersal, and estimates the net displacement of queens to be within the range of those estimated in genetic studies. We suggest that a distinct post-hibernation life history stage consisting mostly of rest with intermittent short flights and infrequent foraging fulfils the dual purpose of ovary development and dispersal prior to nest searching.

Artificial incubation does not affect the post-hatch development, health, or survival of the Lance-tailed Manakin (Chiroxiphia lanceolata), a tropical passerine

Abstract Artificial incubation of avian eggs is used in scientific research, conservation, zoo husbandry, and the commercial poultry industry. However, whether artificial incubation negatively impacts post-hatch nestling phenotypes and survival compared to naturally incubated young has not been explicitly tested. Here, we assess whether nestlings artificially incubated as eggs and returned to their natal nest after hatching experienced negative impacts in development, health, and survival. From 2007 to 2017, we measured mass, mass growth rate, tarsus length, tarsus growth rate, external lesions, ejection from the nest, fledging success, and recruitment of Lance-tailed Manakin (Chiroxiphia lanceolata) nestlings from 209 nests where 1 of 2 eggs was artificially incubated, along with 230 unmanipulated nests. We found no statistically significant difference in the development, health, and survival among nestlings artificially incubated as eggs, their naturally incubated nestmates, and nestlings from unmanipulated nests. Our results indicate that artificial incubation can be a safe and effective tool in the study of free-living birds.

Implications for bird aircraft strike hazard by bald eagles

ABSTRACTBald eagle (Haliaeetus leucocephalus) aircraft strikes have increased since 1998 because their populations have recovered to near historical sizes. Their attraction to airfields and their large body size makes them a danger to aircraft and therefore important to airfield managers. However, bald eagle management is complicated by their special protected status and the place they hold in the eyes of the public. To help airfield managers plan monitoring efforts and make informed management decisions, we studied the movements of 32 bald eagles telemetered as nestlings in the Chesapeake Bay, Virginia, USA, 2013–2018. Managers often need to know when fledged eagles are most likely to move enough to encounter airfields near nests. As fledglings aged, they moved progressively farther from the nest and spent more time away from the nest. Twenty‐eight days after fledging, eagles spent most of the day (81 ± 10% [95% CI]) near the nest (<500 m) and only 7 ± 7% of the daytime away from the nest (>1 km). By day 55 fledglings ventured beyond 2.5 km from the nest and spent 32 ± 15% the day >1 km away from their nest. Distances moved, however, were influenced by proximity of the nest to water, the salinity of that water, and human population density. Eagles left their natal nests and generally migrated out of the Chesapeake Bay 60.5 ± 7.7 days (4 Aug) after fledging and returned to the Chesapeake Bay approximately 220 days later (Mar–Apr). Eighty‐four percent (27 of 32) of the eagles that we tracked encountered 164 airfields across the east coast with 91% of those airfields located within 10 km of the Chesapeake Bay. Encounters with airfields outside the Chesapeake Bay occurred mainly during the first 1.5 years of life, peaking in late fall and early spring. We recorded eagles on Chesapeake Bay airfields during each year, but encounters peaked in April of the first year of the bird's life. April coincides with the height of reported strikes of eagles by aircraft in the region. Our results suggest that eagles fledging from the Chesapeake Bay are an issue for airports near the Chesapeake Bay and for airports across the east coast. Given the continued growth of the population, this issue is likely to continue and grow in significance. © 2019 The Wildlife Society.

Increased egg–nest visual contrast does not induce egg ejection in the eastern phoebe (Sayornis phoebe), an accepter host of the brood parasitic brown-headed cowbird (Molothrus ater).

Hosts of obligate brood parasitic birds can offset the costs of parasitism by rejecting foreign eggs. Like the vast majority of brown-headed cowbird (Molothrus ater) hosts, the eastern phoebe (Sayornis phoebe) paradoxically incurs substantial fitness costs by accepting cowbird parasitism. We investigated whether acceptance of brown-headed cowbird eggs may be mediated via lack of recognition due to crypsis in eastern phoebe nests, and whether egg-rejection behavior could be induced by manipulating egg-nest visual contrast as a means of facilitating parasitic egg detection in an artificial parasitism experiment. We found that brown-headed cowbird eggs have significantly lower achromatic, but not chromatic, visual contrast against the natural nest lining relative to phoebe eggs, suggesting that cowbird eggs may be cryptic in the low ambient light environments of natural or artificial covered ledges where eastern phoebes tend to nest. We also found that despite successfully increasing egg-nest visual contrast in our treatment, eastern phoebes did not reject model parasitic eggs. Our findings are consistent with previous work showing that increased egg-nest visual contrasts do not increase parasitic egg discriminability and rejection in hosts of avian brood parasites. Because sensory modeling showed that eastern phoebes were predicted to be able to visually perceive natural and experimental parasitism events, these hosts are suggested to lack the cognitive flexibility necessary to reject dissimilar eggs in their nests. Future work should determine whether this and other accepter species can be made to reject parasitism by using a more diverse array of artificial egg stimuli. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Nesting near road edges improves nest success and post-fledging survival of White-rumped Shamas (Copsychus malabaricus) in northeastern Thailand

ABSTRACT Road edges in the temperate zone often negatively affect reproductive success, post-fledging survival, and dispersal of forest birds through processes associated with edge habitats. This pattern is less clear in the tropics due to a lack of studies using natural nests and radio-tagged fledglings as well as an almost complete absence of information on nest and fledgling predators. We investigated the influence of road edge on nest success, post-fledging survival, and dispersal of White-rumped Shama (Copsychus malabaricus) in a dry evergreen forest in northeastern Thailand. One hundred nest boxes were placed in forest interior (≥1,000 m from edge of a 5-lane highway) and 100 near forest edge (≤200 m) to assess nesting success. We radio-tracked 50 fledglings from these boxes, 25 each for edge and interior, for 7 weeks after fledging. Nest success and post-fledging survival were 11.6% and 23.6% higher at the edge versus the interior. Predation had the strongest influence on survival, accounting for 100% of nest and 94% of fledgling mortality. Fledglings used locations with denser understory vegetation cover relative to the available habitat, probably to reduce predation risk. Green cat snake (Boiga cyanea) and northern pig-tailed macaque (Macaca leonina), which likely prefer forest interiors over edges, were the primary predators of nests and fledglings in this landscape. There were no significant differences in timing of dispersal and dispersal distance or dispersal direction in relation to proximity to edge. Our results suggest that the impacts of edge effects on the reproductive success of birds appear to be strongly dependent on the habitat preferences of locally dominant predators. Further research will be needed to identify key predators and broadly assess their foraging behaviors in individual landscapes.

Fine-tuned intruder discrimination favors ant parasitoidism.

A diversity of arthropods (myrmecophiles) thrives within ant nests, many of them unmolested though some, such as the specialized Eucharitidae parasitoids, may cause direct damage to their hosts. Ants are known to discriminate between nestmates and non-nestmates, but whether they recognize the strength of a threat and their capacity to adjust their behavior accordingly have not been fully explored. We aimed to determine whether Ectatomma tuberculatum ants exhibited specific behavioral responses to potential or actual intruders posing different threats to the host colony and to contribute to an understanding of complex ant-eucharitid interactions. Behavioral responses differed significantly according to intruder type. Ants evicted intruders that represented a threat to the colony’s health (dead ants) or were not suitable as prey items (filter paper, eucharitid parasitoid wasps, non myrmecophilous adult weevils), but killed potential prey (weevil larvae, termites). The timing of detection was in accordance with the nature and size of the intruder: corpses (a potential source of contamination) were detected faster than any other intruder and transported to the refuse piles within 15 min. The structure and complexity of behavioral sequences differed among those intruders that were discarded. Workers not only recognized and discriminated between several distinct intruders but also adjusted their behavior to the type of intruder encountered. Our results confirm the previously documented recognition capabilities of E. tuberculatum workers and reveal a very fine-tuned intruder discrimination response. Colony-level prophylactic and hygienic behavioral responses through effective removal of inedible intruders appears to be the most general and flexible form of defense in ants against a diverse array of intruders. However, this generalized response to both potentially lethal and harmless intruders might have driven the evolution of ant-eucharitid interactions, opening a window for parasitoid attack and allowing adult parasitoid wasps to quickly leave the natal nest unharmed.

Meta‐analyses of nest predation in temperate Australian forests and woodlands

AbstractNest predation is the leading cause of nesting failure. Thus it is a crucial area of research needed to inform conservation management and to understand the life history of birds. I surveyed the literature to review the identity of nest predators and the factors affecting nest predation, in Australia using 177 studies. Overall, 94 nest predators were identified when incorporating artificial nests, 69 without. Using only natural nests, the Pied Currawong Strepera graculina was the most frequently reported nest predator. Five nest predators, including Pied Currawong, depredated 40% of the prey measured by the number of prey species taken. Yet, 60% of predation was carried out by the other 64 species, which included by the order of importance birds, mammals, reptiles, frogs and ants. Predation at cup and dome nests was more frequently reported than at burrow, ground and hollow nests. Only 28% of predators were observed at both artificial and natural nests suggesting artificial nests have limited, but not negligible, ability as tools for identifying predators. There was a highly significant and positive correlation between predator and prey masses. The predator prey mass ratio was calculated with a mean 0.25 and a median 0.22, a result closely matching with the proportional size of prey taken by raptors. The finding that predator size is proportional to prey opens a pathway for more life history and conservation research.