Do Lions Panthera leo Actively Select Prey or Do Prey Preferences Simply Reflect Chance Responses via Evolutionary Adaptations to Optimal Foraging?

Research on coursing predators has revealed that actions throughout the predatory behavioral sequence (using encounter rate, hunting rate, and kill rate as proxy measures of decisions) drive observed prey preferences. We tested whether similar actions drive the observed prey preferences of a stalking predator, the African lion Panthera leo. We conducted two 96 hour, continuous follows of lions in Addo Elephant National Park seasonally from December 2003 until November 2005 (16 follows), and compared prey encounter rate with prey abundance, hunt rate with prey encounter rate, and kill rate with prey hunt rate for the major prey species in Addo using Jacobs' electivity index. We found that lions encountered preferred prey species far more frequently than expected based on their abundance, and they hunted these species more frequently than expected based on this higher encounter rate. Lions responded variably to non-preferred and avoided prey species throughout the predatory sequence, although they hunted avoided prey far less frequently than expected based on the number of encounters of them. We conclude that actions of lions throughout the predatory behavioural sequence, but particularly early on, drive the prey preferences that have been documented for this species. Once a hunt is initiated, evolutionary adaptations to the predator-prey interactions drive hunting success.     

Profitability, encounter rates, and prey choice of African lions

The prey preferences of African lions (Panthera leo) in SerengetiNational Park, Tanzania, were examined in three ways. First,lion encounter rates with prey types were measured and comparedwith a random sample of the prey population. Lions encounteredmore wart hogs (Phacochoerus aethiopicus), Grant's gazelles(Gazella granti), wildebeests (ConnochaeUs taurinus), and zebras(Equus burchelli) than expected. Second, preferred prey typesof lions were identified using conditional logit analysis. Lionspreferred to hunt small prey groups, groups that were closerthan 200 m, and groups that contained wart hogs, wildebeests,or zebras. Third, a risk-minimization optimal foraging modeland a rate-maximization model were used to predict lion preferences.The foraging theory models predict that preferences should changewith season and with lion group size. Qualitative support wasfound for most of these predictions.     

The response of lions (<Emphasis Type="Italic">Panthera leo</Emphasis>) to changes in prey abundance on an enclosed reserve in South Africa

Large mammalian carnivores place significant pressure on their prey populations and this is exacerbated within the fenced reserves of Africa. However, foraging theory predicts that diet switching by predators may mitigate this pressure. In this study, we use data collected between 2003 and 2007 from an enclosed system in the Eastern Cape Province of South Africa to examine the response of lions Panthera leo to changes in the abundance of two important prey species — kudu Tragelaphus strepsiceros and warthog Phacochoerus africanus. As the relative abundance of warthogs increased, the number of kudu kills decreased significantly, whereas warthog kills became significantly more frequent. A similar pattern was observed for lion prey preference and the switch from kudu to warthog was also reflected in a significant decrease in the mean prey mass. Our results suggest that a diet shift occurs in lions and that the change in diet is primarily in response to an increase in warthog numbers. Prey switching may promote the persistence of predator–prey systems, which is particularly important for fenced systems where natural immigration of prey is not possible. However, continued collection and analysis of long-term observational data from the multipredator, multiprey systems of Africa is required to facilitate a full understanding of predator–prey dynamics.     

Examining the potential for nutritional stress in young Steller sea lions: physiological effects of prey composition

The effects of high- and low-lipid prey on the body mass, body condition, and metabolic rates of young captive Steller sea lions (Eumetopias jubatus) were examined to better understand how changes in prey composition might impact the physiology and health of wild sea lions and contribute to their population decline. Results of three feeding experiments suggest that prey lipid content did not significantly affect body mass or relative body condition (lipid mass as a percent of total mass) when sea lions could consume sufficient prey to meet their energy needs. However, when energy intake was insufficient to meet daily requirements, sea lions lost more lipid mass (9.16±1.80 kg±SE) consuming low-lipid prey compared with eating high-lipid prey (6.52±1.65 kg). Similarly, the sea lions lost 2.7±0.9 kg of lipid mass while consuming oil-supplemented pollock at maintenance energy levels but gained 5.2±2.7 kg lipid mass while consuming identical energetic levels of herring. Contrary to expectations, there was a 9.7±1.8% increase in metabolism during mass loss on submaintenance diets. Relative body condition decreased only 3.7±3.8% during periods of imposed nutritional stress, despite a 10.4±4.8% decrease in body mass. These findings raise questions regarding the efficacy of measures of relative body condition to detect such changes in nutritional status among wild animals. The results of these three experiments suggest that prey composition can have additional effects on sea lion energy stores beyond the direct effects of insufficient energy intake.     

Inbreeding depression increases susceptibility to bovine tuberculosis in lions: an experimental test using an inbred-outbred contrast through translocation

Disease can dramatically influence the dynamics of endangered wildlife populations, especially when they are small and isolated, with increased risk of inbreeding. In Hluhluwe-iMfolozi Park (HiP), a small, enclosed reserve in South Africa, a large lion (Panthera leo) population arose from a small founder group in the 1960s and started showing conspicuous signs of inbreeding. To restore the health status of the HiP lion population, outbred lions were translocated into the existing population. In this study, we determined the susceptibility to bovine tuberculosis (bTB), and the prevalence of antibody to feline viruses of native lions, and compared the findings with those from translocated outbred lions and their offspring. Antibodies to feline herpesvirus, feline calicivirus, feline parvovirus, and feline coronavirus were present in the lion population, but there was no significant difference in antibody prevalence between native and translocated lions and their offspring, and these feline viruses did not appear to have an effect on the clinical health of HiP lions. However, feline immunodeficiency virus (FIV), which was previously absent from HiP, appears to have been introduced into the lion population through translocation. Within 7 yr, the prevalence of antibody to FIV increased up to 42%. Bovine tuberculosis posed a major threat to the inbred native lion population, but not to translocated lions and their offspring. More than 30% of the native lion population died from bTB or malnutrition compared with <2% of the translocated lions and their offspring. We have demonstrated that management of population genetics through supplementation can successfully combat a disease that threatens population persistence. However, great care must be taken not to introduce new diseases into populations through translocation.     

Consumption of introduced prey by native predators: Argentine ants and pit-building ant lions

When populations of native predators are subsidized by numerically dominant introduced species, the structure of food webs can be greatly altered. Surprisingly little is known, however, about the general factors that influence whether or not native predators consume introduced species. To learn more about this issue, we examined how native pit-building ant lions (Myrmeleon) are affected by Argentine ant (Linepithema humile) invasions in coastal southern California. Compared to areas without L. humile, invaded areas contained few native ant species and were deficient in medium-sized and large bodied native ants. Based on these differences, we predicted that Argentine ants would negatively affect ant lion larvae. Contrary to this expectation, observational surveys and laboratory growth rate experiments revealed that Myrmeleon were heavier, had longer mandibles, and grew more quickly when their main ant prey were Argentine ants rather than native ants. Moreover, a field transplant experiment indicated that growth rates and pupal weights were not statistically different for larval ant lions reared in invaded areas compared to those reared in uninvaded areas. Argentine ants were also highly susceptible to capture by larval Myrmeleon. The species-level traits that presumably make Argentine ant workers susceptible to capture by larval ant lions—small size and high activity levels—appear to be the same characteristics that make them unsuitable prey for vertebrate predators, such as horned lizards. These results underscore the difficulties in predicting whether or not numerically dominant introduced species serve as prey for native predators.     

In the absence of a “landscape of fear”: How lions,hyenas, and cheetahs coexist

Aggression by top predators can create a “landscape of fear” in which subordinate predators restrict their activity to low‐risk areas or times of day. At large spatial or temporal scales, this can result in the costly loss of access to resources. However, fine‐scale reactive avoidance may minimize the risk of aggressive encounters for subordinate predators while maintaining access to resources, thereby providing a mechanism for coexistence. We investigated fine‐scale spatiotemporal avoidance in a guild of African predators characterized by intense interference competition. Vulnerable to food stealing and direct killing, cheetahs are expected to avoid both larger predators; hyenas are expected to avoid lions. We deployed a grid of 225 camera traps across 1,125 km² in Serengeti National Park, Tanzania, to evaluate concurrent patterns of habitat use by lions, hyenas, cheetahs, and their primary prey. We used hurdle models to evaluate whether smaller species avoided areas preferred by larger species, and we used time‐to‐event models to evaluate fine‐scale temporal avoidance in the hours immediately surrounding top predator activity. We found no evidence of long‐term displacement of subordinate species, even at fine spatial scales. Instead, hyenas and cheetahs were positively associated with lions except in areas with exceptionally high lion use. Hyenas and lions appeared to actively track each, while cheetahs appear to maintain long‐term access to sites with high lion use by actively avoiding those areas just in the hours immediately following lion activity. Our results suggest that cheetahs are able to use patches of preferred habitat by avoiding lions on a moment‐to‐moment basis. Such fine‐scale temporal avoidance is likely to be less costly than long‐term avoidance of preferred areas: This may help explain why cheetahs are able to coexist with lions despite high rates of lion‐inflicted mortality, and highlights reactive avoidance as a general mechanism for predator coexistence.     

Dietary partitioning of three large carnivores in Majete Wildlife Reserve,Malawi

Between 2011 and 2012, the carnivore guild in Majete Wildlife Reserve (MWR), Malawi, was restored following the reintroduction of lion (Panthera leo) and leopard (Panthera pardus). The aim of this study was to describe and compare the diet of lion, leopard and resident spotted hyaena (Crocuta crocuta) using scat analysis. Lions and spotted hyaenas displayed the greatest dietary overlap (O_ab = 0.88) and selected mainly medium- to large-bodied prey species. Lions had a mean preferred prey weight of 120.33 ± 42.14 kg (SE), with warthog (Phacochoerus africanus) and waterbuck (Kobus ellipsiprymnus) making up 60.64% of relative biomass consumed. Spotted hyaenas had a mean preferred prey weight of 102.40 ± 41.69 kg and had a more generalised diet (B_a = 0.46) compared to lions (B_a = 0.36). In contrast, leopards occupied a dietary niche substantially lower than that of lions and spotted hyaenas, selecting relatively smaller prey with a mean preferred prey weight of 27.50 ± 6.74 kg. Our results suggest that coexistence between the resident hyaena and reintroduced lion and leopard in MWR is facilitated by dietary partitioning. We advise long-term monitoring of reintroduced carnivores in small, enclosed reserves to assess their impacts on predator and prey populations.     

Translocating lions into an inbred lion population in the Hluhluwe-iMfolozi Park, South Africa

A fundamental problem in conservation biology is the risk of inbreeding in fragmented and declining populations. In the Hluhluwe-iMfolozi Park (HiP), a small, enclosed reserve in South Africa, a large lion Panthera leo population arose from a founder group of five individuals in the 1960s. The HiP lion population went through a persistent decline and showed indications of inbreeding depression. To restore the genetic variation of the inbred HiP lion population, new lions were translocated into the existing population. Translocated females formed stable associations and established enduring pride areas with other translocated lionesses, but did not bond into native female prides. The translocated male coalition was more successful in gaining and maintaining residence in a pride than the translocated lone male that split off on his own from the male coalition. Litter size and cub survival was about twice as high for pairings involving at least one translocated parent than for pairings of two native lions. It is therefore possible to infuse new genes rapidly and successfully into a small, isolated lion population. Such translocations may become an important adaptive management tool as lion populations become increasingly fragmented.     

Proportion of prey consumed can be determined from faecal DNA using real-time PCR

Reconstructing the diets of pinnipeds by visually identifying prey remains recovered in faecal samples is challenging because of differences in digestion and passage rates of hard parts. Analysing the soft-matrix of faecal material using DNA-based techniques is an alternative means to identify prey species consumed, but published techniques are largely nonquantitative, which limits their usefulness for some applications. We further developed and validated a real-time PCR technique using species-specific mitochondrial DNA primers to quantify the proportion of prey in the diets of Steller sea lions (Eumetopias jubatus), a pinniped species thought to be facing significant diet related challenges in the North Pacific. We first demonstrated that the proportions of prey tissue DNA in mixtures of DNA isolated from four prey species could be estimated within a margin of ～ 12% of the percent in the mix. These prey species included herring Clupea palasii, eulachon Thaleichthyes pacificus, squid Loligo opalescens and rosethorn rockfish Sebastes helvomaculatus. We then applied real-time PCR to DNA extracted from faecal samples obtained from Steller sea lions in captivity that were fed 11 different combinations of herring, eulachon, squid and Pacific ocean perch rockfish (Sebastes alutus), ranging from 7% to 75% contributions per meal (by wet weight). The difference between the average percentage estimated by real-time PCR and the percentage of prey consumed was generally <12% for all diets fed. Our findings indicate that real-time PCR of faecal DNA can detect the approximate relative quantity of prey consumed for complex diets and prey species, including cephalopods and fish.     

Can an herbivore affect where a top predator kills its prey by modifying woody vegetation structure?

In large mammal communities, little is known about modification of interspecific interactions through habitat structure changes. We assessed the effects of African elephants (Loxodonta africana) on features of woody habitat structure that can affect predator–prey interactions. We then explored how this can influence where African lions (Panthera leo) kill their prey. Indeed, lions are stalk-and-ambush predators and habitat structure and concealment opportunities are assumed to influence their hunting success. During 2 years, in Hwange National Park, Zimbabwe, kill sites (n = 167) of GPS-collared lions were characterized (visibility distance for large mammals, distance to a potential ambush site and presence of elephant impacts). We compared characteristics of lion kill sites with characteristics of random sites (1) at a large scale (i.e. in areas intensively used by lions, n = 418) and (2) at the microhabitat scale (i.e. in the direct surrounding available habitat, < 150 m, n = 167). Elephant-impacted sites had a slightly higher visibility and a longer distance to a potential ambush site than non-impacted sites, but these relationships were characterized by a high variability. At large scale, kill sites were characterized by higher levels of elephant impacts compared to random sites. At microhabitat scale, compared to the direct nearby available habitat, kill sites were characterized by a reduced distance to a potential ambush site. We suggest a conceptual framework whereby the relative importance of habitat features and prey abundance could change upon the scale considered.     

Assessment of Competition between Fisheries and Steller Sea Lions in Alaska Based on Estimated Prey Biomass,Fisheries Removals and Predator Foraging Behaviour

A leading hypothesis to explain the dramatic decline of Steller sea lions (Eumetopias jubatus) in western Alaska during the latter part of the 20th century is a change in prey availability due to commercial fisheries. We tested this hypothesis by exploring the relationships between sea lion population trends, fishery catches, and the prey biomass accessible to sea lions around 33 rookeries between 2000 and 2008. We focused on three commercially important species that have dominated the sea lion diet during the population decline: walleye pollock, Pacific cod and Atka mackerel. We estimated available prey biomass by removing fishery catches from predicted prey biomass distributions in the Aleutian Islands, Bering Sea and Gulf of Alaska; and modelled the likelihood of sea lions foraging at different distances from rookeries (accessibility) using satellite telemetry locations of tracked animals. We combined this accessibility model with the prey distributions to estimate the prey biomass accessible to sea lions by rookery. For each rookery, we compared sea lion population change to accessible prey biomass. Of 304 comparisons, we found 3 statistically significant relationships, all suggesting that sea lion populations increased with increasing prey accessibility. Given that the majority of comparisons showed no significant effect, it seems unlikely that the availability of pollock, cod or Atka mackerel was limiting sea lion populations in the 2000s.     

A CRITICAL REVIEW OF THE REGIME SHIFT-"JUNK FOOD"-NUTRITIONAL STRESS HYPOTHESIS FOR THE DECLINE OF THE WESTERN STOCK OF STELLER SEA LION

Steller sea lions ( Eumetopias jubatus ) in the central and western Gulf of Alaska, Aleutian Islands, and Bering Sea have declined by 80% in the last 30 yr. One hypothesis for the decline in this western Steller sea lion population is that a climate regime shift in 1976–1977 changed the species composition of the fish community and reduced the nutritional quality (energy density) of the sea lion prey field. This in turn led to nutritional stress and reduced individual fitness, survival, and reproduction of sea lions. Implications of this regime shift-"junk food" hypothesis are that (1) the recruitment and abundance of supposed high quality species ( e.g. , Pacific herring, Clupea pallasi ) decreased while those of supposed low quality ( e.g. , species in the family Gadidae) increased following the regime shift, (2) Steller sea lion diets shifted in response to this change in fish community structure, and (3) a diet composed principally of gadids ( e.g. , walleye pollock, Theragra chalcogramma ) is detrimental to sea lion fitness and survival. We examine data relating to each of these implications and find little support for the hypothesis that increases in the availability and consumption of gadids following the regime shift are primarily responsible for the decline of the western population of Steller sea lion.     

Seasonal and sex-specific prey composition of black-footed catsFelis nigripes

During a 6-year field study on the game farm ‘Benfontein’ in the central Republic of South Africa 1725 prey items were observed consumed by 17 free-ranging habituated black-footed catsFelis nigripes Burchell, 1824. Average prey size was 24.1 g. Eight males fed on significantly larger prey (27.9 g) than 9 females (20.8 g). Fifty-four prey species were classified by their average mass into 8 different size classes, 3 for mammals, 3 for birds, 1 for amphibians/reptiles, and 1 for invertebrates. Small mammals (5–40 g) constituted the most important prey class (39%) of total prey biomass followed by larger mammals (>100 g; 17%) and small birds (<40 g; 16%). Mammals and birds pooled comprised 72% and 26% of total prey biomass, respectively, whereas invertebrates and amphibians/reptiles combined constituted just 2% of total prey mass consumed. Three seasons of 4-months duration were recognized. Heterotherm prey items were unavailable during winter, when larger birds and mammals (> 100 g) were mainly consumed. Small rodents like the large-eared mouseMalacothrix typica, captured 595 times by both sexes, were particularly important during the reproductive season for females with kittens. Male black-footed cats showed less variation between prey size classes consumed among climatic seasons. This sex-specific difference in prey size consumption may help to reduce intra-specific competition.     

Linking seasonal distribution patterns with prey availability in a central-place forager, the Steller sea lion

Aim We used a novel approach to infer foraging areas of a central‐place forager, the Steller sea lion (Eumetopias jubatus), by assessing changes in the temporal and spatial distribution patterns of sea lions at terrestrial sites. Specifically, our objectives were (1) to classify seasonal distribution patterns of Steller sea lions and (2) to determine to what extent the seasonal distribution of Steller sea lions is explained by seasonal concentrations of prey. Location Southeast Alaska, USA. Methods Steller sea lions of all age classes were counted monthly (2001–04) by aerial surveys at 28 terrestrial sites. Hierarchical cluster analysis and principal components analysis were used to classify seasonal distribution patterns of Steller sea lions at these terrestrial sites. We estimated the proportion of sea lions in the study area that were associated with each seasonal distribution pattern. Results Multivariate ordination techniques revealed four distinct seasonal distributional patterns. During December, 55% of the sea lions in the study area were found at Type 1 sites, located near over‐wintering herring aggregations. During May, 56% of sea lions were found at Type 2 sites, near aggregations of spring‐spawning forage fish. In July, 78% of sea lions were found at Type 3 sites, near summer migratory corridors of salmon. During September, 44% of sea lions were found at Type 4 sites, near autumn migratory corridors of salmon. Main conclusions Seasonal attendance patterns of sea lions were commonly associated with the seasonal availability of prey species near terrestrial sites and reflected seasonal foraging patterns of Steller sea lions in Southeast Alaska. A reasonable annual foraging strategy for Steller sea lions is to forage on herring (Clupea pallasii) aggregations in winter, spawning aggregations of forage fish in spring, salmon (Oncorhynchus spp.) in summer and autumn, and pollock (Theragra chalcogramma) and Pacific hake (Merluccius productus) throughout the year. The seasonal use of haulouts by sea lions and ultimately haulout‐specific foraging patterns of Steller sea lions depend in part upon seasonally available prey species in each region.     

Seasonal Diet and Prey Preference of the African Lion in a Waterhole-Driven Semi-Arid Savanna

Large carnivores inhabiting ecosystems with heterogeneously distributed environmental resources with strong seasonal variations frequently employ opportunistic foraging strategies, often typified by seasonal switches in diet. In semi-arid ecosystems, herbivore distribution is generally more homogeneous in the wet season, when surface water is abundant, than in the dry season when only permanent sources remain. Here, we investigate the seasonal contribution of the different herbivore species, prey preference and distribution of kills (i.e. feeding locations) of African lions in Hwange National Park, Zimbabwe, a semi-arid African savanna structured by artificial waterholes. We used data from 245 kills and 74 faecal samples. Buffalo consistently emerged as the most frequently utilised prey in all seasons by both male (56%) and female (33%) lions, contributing the most to lion dietary biomass. Jacobs’ index also revealed that buffalo was the most intensively selected species throughout the year. For female lions, kudu and to a lesser extent the group “medium Bovidae” are the most important secondary prey. This study revealed seasonal patterns in secondary prey consumption by female lions partly based on prey ecology with browsers, such as giraffe and kudu, mainly consumed in the early dry season, and grazers, such as zebra and suids, contributing more to female diet in the late dry season. Further, it revealed the opportunistic hunting behaviour of lions for prey as diverse as elephants and mice, with elephants taken mostly as juveniles at the end of the dry season during droughts. Jacobs’ index finally revealed a very strong preference for kills within 2 km from a waterhole for all prey species, except small antelopes, in all seasons. This suggested that surface-water resources form passive traps and contribute to the structuring of lion foraging behaviour.     

Demography of lions in relation to prey and habitat in the Maasai Mara National Reserve, Kenya

We studied lion demography in the Maasai Mara National Reserve between September 1990 and April 1992, with a special emphasis on the spatial and seasonal variation in demographic characteristics. Lion density (0.2–0.4 lions km^?2) and pride size (range 8–48) were high because of a high resident prey biomass (10 335 kg km^?2) augmented by migrant prey to 26 092 kg km^?2 in the dry season. Overall, their sex ratio was almost at parity and varied neither spatially nor seasonally. Sex ratio was even among subadults but skewed toward males and females among cubs and adults, respectively. This implies an increasing differential mortality of males with age through subadulthood. The age ratio varied seasonally because of a birth peak in March–June and an influx of subadults into the reserve during July–August, coincident with increases in migrant prey. The birth peak was apparently preceded by another peak in mating activity falling between November and May. Further research should investigate the precise causes of the biased cub sex ratio, low lion density in the Mara Triangle and the higher ratio of subadults in Musiara than in the Mara Triangle or Sekenani.     

Predators target rare prey in coral reef fish assemblages

Predation can result in differing patterns of local prey diversity depending on whether predators are selective and, if so, how they select prey. A recent study comparing the diversity of juvenile fish assemblages among coral reefs with and without predators concluded that decreased prey diversity in the presence of predators was most likely caused by predators actively selecting rare prey species. We used several related laboratory experiments to explore this hypothesis by testing: (1) whether predators prefer particular prey species, (2) whether individual predators consistently select the same prey species, (3) whether predators target rare prey, and (4) whether rare prey are more vulnerable to predation because they differ in appearance/colouration from common prey. Rare prey suffered greater predation than expected and were not more vulnerable to predators because their appearance/colouration differed from common prey. Individual predators did not consistently select the same prey species through time, suggesting that prey selection behaviour was flexible and context dependent rather than fixed. Thus, selection of rare prey was unlikely to be explained by simple preferences for particular prey species. We hypothesize that when faced with multiple prey species predators may initially focus on rare, conspicuous species to overcome the sensory confusion experienced when attacking aggregated prey, thereby minimizing the time required to capture prey. This hypothesis represents a community-level manifestation of two well-documented and related phenomena, the “confusion effect” and the “oddity effect”, and may be an important, and often overlooked, mechanism by which predators influence local species diversity.     

Effects of intraguild predators on nest-site selection by prey

Nest-site selection involves tradeoffs between the risk of predation (on females and/or nests) and nest-site quality (microenvironment), and consequently suitable nesting sites are often in limited supply. Interactions with “classical” predators (e.g., those not competing for shared resources) can strongly influence nest-site selection, but whether intraguild predation also influences this behavior is unknown. We tested whether risk of predation from an intraguild predator [the diurnal scincid lizard Eutropis (Mabuya) longicaudata] influences nest-site selection by its prey (the nocturnal gecko Gekko hokouensis) on Orchid Island, Taiwan. These two species putatively compete for shared resources, including invertebrate prey and nesting microhabitat, but the larger E. longicaudata also predates G. hokouensis (but not its hard-shelled eggs). Both species nested within a concrete wall containing a series of drainage holes that have either one (“closed-in”) or two openings (“open”). In allopatry, E. longicaudata preferred to nest within holes that were plugged by debris (thereby protecting eggs from water intrusion), whereas G. hokouensis selected holes that were open at both ends (facilitating escape from predators). When we experimentally excluded E. longicaudata from its preferred nesting area, G. hokouensis not only nested in higher abundances, but also modified its nest-site selection, such that communal nesting was more prevalent and both open and closed-in holes were used equally. Egg viability was unaffected by the choice of hole type, but was reduced slightly (by 7%) in the predator exclusion area (presumably due to higher local incubation temperatures). Our field experiment demonstrates that intraguild predators can directly influence the nest density of prey by altering maternal nest-site selection behavior, even when the predator and prey are active at different times of day and the eggs are not at risk of predation.