Nest Usurpation Research Articles

Defensive behavior and chemical deterrence against ants in the stingless bee genus Trigona (Apidae, Meliponini)

SummaryFive species of Trigona (Apidae, Meliponini) in Borneo were tested for anti-predator deterrents, which potentially contribute to the protection of individual bees as well as their colony. Feeding choice experiments were performed with three predatory ant species. In most cases, ants significantly preferred bees that were washed with solvents (hexane and chloroform respectively) over untreated bees. This shows that stingless bees possess ant-deterrent substances. We suggest that plant-originated terpenes on the bees' cuticles contribute to this deterrent effect. Furthermore, we observed behavioral defences of two Trigona species at their colony entrance. Upon simulated nest intrusion of ant workers, bees predominantly reacted with aggressive biting, but also utilized resin-like substances as glue against intruders. Therefore, stingless bees utilize a combination of defences that may help to deter ants as potential predators inside and outside the nest.

BREEDING PHENOLOGY AND SUCCESS OF BLACK SWIFTS IN BOX CANYON, OURAY, COLORADO

Abstract This study presents 11 years of nesting success and phenology data for Black Swifts (Cypseloides niger) at Box Canyon in Ouray, Colorado. Nest data were recorded on a near-daily basis for 160 nest attempts. Nesting success was 72% and mean and extreme dates of nesting events, including arrival, egg-laying, onset of incubation, hatching, and fledging are reported. On average, Black Swifts arrived on 13 June, egg laying started on 28 June, incubation started on 1 July, hatching occurred on 26 July, and fledging occurred on 13 September. The average incubation period was 26 days and the nestling phase was 48 days. In seven instances, a second egg appeared after loss of the first egg and, in one case, a third egg appeared. It was not possible to ascertain whether second or third eggs represented a renesting attempt or nest usurpation.

The nest-holding grass goby (Zosterisessor ophiocephalus) male adjusts the spawning activity in relation to parasitic nest intrusions

This study examines the temporal pattern of spawning behavior by the territorial (i.e. nest-holding) grass goby male, Zosterisessor ophiocephalus, in response to sneak intrusions by the small parasitic male under controlled laboratory conditions. The spawning activity of the territorial male consists of a sequence of upside–down movements on the ceiling of the nest accompanied by undulations of the body and sperm release. Five pairs of one territorial male and one parasitic male, each kept inside a large tank provided with an artificial buried nest (always occupied by the territorial male) and one small tunnel-shaped shelter (always occupied by the small male), were observed during one-female spawning taking place in the innermost part of the nest (i.e. the nest chamber). During the spawning, the presence of the small male nearby the nest openings elicited aggressive behavior and increased nest patrolling by the territorial male. In one spawn the small male never attempted to enter the nest. In four spawns the small male entered one to three times the nest chamber (sneaks), staying there from 2 to 203 s until the large male chased him away. The temporal patterning of the spawning activity by the territorial male (bouts of upside–down, U–D), and its changes following a sneak by the small male, were investigated using bout analysis and correlative tests. Results showed the length of bouts U–D did not change significantly after a sneak intrusion. whereas gap length (i.e. the period between subsequent bouts U–D) decreased significantly after each sneak intrusion. The mean duty cycle of bouts U–D tended to be positively correlated to the number of sneaker intrusions of each replicate. Results are discussed in the light of current knowledge on sperm competition among externally fertilizing teleosts.

Nest Usurpation by Red-headed Woodpeckers in Southeastern Montana

Red-headed Woodpeckers (Melanerpes erythrocephalus) occasionally usurp nests of other species. I compared incidence of nest usurpation in logged and non-logged treatments in a burned ponderosa pine (Pinus ponderosa) forest in 2004 and 2005. I predicted that usurpation would occur more often on logged than non-logged sites because Red-headed Woodpeckers tend to nest in more open habitats. Red-headed Woodpeckers nested more often and usurped a greater proportion of host species in logged (n = 6) than non-logged (n = 3) areas, despite host cavities being more abundant on the non-logged treatment. Usurping Red-headed Woodpecker pairs initiated nesting earlier (x̄ = 12 May ± 2 days) than pairs that excavated cavities (18 May ± 2 days) which implies an existing benefit to offset the cost of interspecific conflict.

Competition with Egyptian Geese Alopochen aegyptiaca overrides environmental factors in determining productivity of Black Sparrowhawks Accipiter melanoleucus

We studied a population of Black Sparrowhawks Accipiter melanoleucus that has recently colonized the Cape Peninsula, South Africa. Black Sparrowhawks are winter breeders: over most of their range winters are dry, but the Cape Peninsula has a Mediterranean climate, with most rain falling in winter. The birds bred at an average density of 38 pairs/100 km2. Monitoring of 70 breeding attempts by 26 pairs showed that the birds favoured large stands of trees for breeding. Birds breeding in smaller stands were more randomly spaced, dispersion being determined by habitat availability. Parameters related to climate, habitat and aspects of nest‐site selection failed to predict the birds’ productivity despite the fact that they had recently colonized a novel climatic window. Rather, productivity was best explained by the probability of nest usurpation by highly aggressive Egyptian Geese Alopochen aegyptiaca. Pairs encountering Goose usurpation problems raised an average of 0.76 chicks per breeding attempt, compared with 1.58 chicks for pairs without Geese. The only defence against nest usurpation by Geese appears to be the construction of multiple nests, an option most available to and most exploited by birds breeding in large stands of trees.

Interspecific Egg-dumping by a Violet-green Swallow in an Active Western Bluebird Nest

Abstract We observed a Violet-green Swallow (Tachycineta thalassina) laying an egg in an active Western Bluebird (Sialia mexicana) nest. The Western Bluebird male and not the female, was aggressive to the Violet-green Swallow but the swallow remained to lay the egg. This is the first documented incidence of which we are aware involving altricial interspecific egg-laying during the nestling phase. We suggest the timing of this event was more consistent with incidental egg deposition, or egg-dumping, than brood parasitism or nest usurpation.

Extra‐pair copulation and intraspecific nest intrusions in the Northern Goshawk Accipiter gentilis

Detailed descriptions of the behaviour of individual birds engaged in extra-pair copulations (EPCs) are comparatively rare. This might be due to the fact that EPCs occur infrequently and/or that EPC-seeking males and females usually behave in a secretive manner (Birkhead & Moller 1992a). Even in birds of prey, often observed intensively in the field, detailed reports of EPCs are scarce (e.g. Birkhead & Lessells 1988, McGrady 1991, Sodhi 1991, Negro et al. 1992, Arroyo 1999). Observational data are important, however, as they can shed light on aspects of sperm competition (e.g. age and status of intruders, timing of EPC events, behaviour of the sexes), which may pass unnoticed in quantitative DNA-profiling studies. The Northern Goshawk Accipiter gentilis is a socially monogamous, territorial raptor (Squires & Reynolds 1997, Rutz et al . in press) with a distinct division of sex roles during the breeding season. Males provision their mates and, later, their offspring with prey, whereas females incubate the eggs, care for the young and defend the nesting territory (Squires & Reynolds 1997). During the males’ foraging trips, their mates remain unattended at the nest-sites, where they might either seek EPCs or become victim to forced copulation attempts by intruders. The latter case, however, is unlikely in the Goshawk, as females are about a third heavier than males (Squires & Reynolds 1997) and are therefore capable of fighting off unwanted copulation partners. Male birds may reduce the risk of cuckoldry by two main strategies: (i) they can guard their mates by close following; or (ii) copulate with them at a high rate during the fertile period (Birkhead & Moller 1992a). Male Goshawks cannot follow their partners closely while hunting. They can, however, attempt to maximize the time spent near the nest, and hence their mates, when the probability of fertilization is high (i.e. close to and during egg-laying). This strategy is known as ‘mate attendance’ (Birkhead & Moller 1992a). Both mate attendance and frequent copulations have been recorded in the Goshawk (Holstein 1942, Moller 1987). So far, only genetic evidence has existed for the occurrence of EPCs in the Goshawk (Gavin et al . 1998). In this paper the first observation of an EPC in this species is described, and nine cases of intraspecific nest intrusions are reported. Radiotracking data on the spatio-temporal organization and the behaviour of males of three breeding pairs were used to address predictions from the mateattendance and frequent-mating hypotheses (Birkhead & Moller 1992a).

Dufour's gland secretion as a repellent used during usurpation by the slave-maker ant Rossomyrmex minuchae

In slave-making ants, the invasion of the host colony by newly mated queens is a critical stage. We studied the strategy used by Rossomyrmex minuchae queens to invade their host Proformica longiseta. Field observations revealed that queens enter the host nest unchallenged by the host workers in the vicinity of the nest entrance. Pre-usurpation queens were found to possess a highly inflated Dufour's gland, which considerably reduces in size after successful usurpation. Chemical analysis of these queen glands revealed tetradecanal to be the major product in pre-usurpation Rossomyrmex queens, but to be almost absent in queens that have been adopted by P. longiseta. We consequently hypothesized that tetradecanal is a repellent that is used by queens to prevent host worker aggression. We tested its repellent effect by attempting to deter starved, highly motivated workers from a droplet of honey. Tetradecanal indeed proved to be highly repellent both to host worker P. longiseta and non-host worker Formica selysi. It was even more powerful than limonene, a reported general ant repellent. These results are consistent with the hypothesis that R. minuchae queens use Dufour's gland secretion as a weapon during nest usurpation. The general use of tetradecanal as a defensive compound, and its seemingly non-specific repellent effect on ants, indicate that it may act as a general ant repellent. Its adoption by R. minuchae queens thus provides them with an efficient defensive and offensive chemical weapon during their long and risky search for new host nests.

Sapsuckers Usurp a Nuthatch Nest

We document for the first time a Red-naped Sapsucker (Sphyrapicus nuchalis) usurping the nest of a Red-breasted Nuthatch (Sitta canadensis). A nuthatch nest in the incubation phase was usurped by a male Red-naped Sapsucker on 23 May 2003, and a sapsucker nest was initiated in the cavity on 1 June. Red-naped Sapsuckers are primary cavity excavators that normally nest in live and dead quaking aspens (Populus tremuloides) infected with heart rot fungus (Fomes spp.). Red-breasted Nuthatches are weak excavators that most commonly nest in broken-topped conifer snags. Nest usurpation was likely due to a shortage of suitable nest sites in our study plot.

Seasonal nest usurpation of European colonies by African swarms in Arizona, USA

Summary. Nest usurpation is a form of reproductive parasitism that may contribute to the ability of African bees to displace European honey bees in the Americas. We examined nest usurpation by African swarms over a two-year period in a southern-Arizona apiary that contained 76 five-frame European colonies. We observed a mean annual usurpation rate of 21%, with strong seasonal trends in usurpation activity. Most usurpations occurred from October‐December, with a minor peak of usurpation activity in the spring-summer months. The seasonal patterns of usurpation corresponded with the reproductive swarming season in spring and summer and the absconding season in the fall-winter months. Queenless colonies, colonies that contained a queen confined in a cage, and those that had been recently requeened were 2‐8 times more likely to be invaded than were colonies that contained an actively laying queen, suggesting that queen condition may have a major influence on hostcolony susceptibility to usurpation. This trend was particularly pronounced in October‐December, during which months the usurpation rates experienced by caged-queen and queenless colonies approached 20‐50%. Our results show that nest usurpation is seasonally frequent among honey bees in the southwestern U.S., which suggests that reproductive parasitism contributes to the invasion success of African honey bees and possibly other introduced social insect species.

Dynamics of chemical mimicry in the social parasite waspPolistes semenowi(Hymenoptera: Vespidae)

Chemical cues are so important in the recognition mechanism of social insects that most social parasites (which rely on hosts to rear their brood) have been documented as overcoming the mechanism by which colony residents recognize non-nestmates, by mimicking the odour of the usurped colony. We simulated in the laboratory the process by which the obligate social parasite, Polistes semenowi, invades nests of the host species, Polistes dominulus, in the field and analysed the epicuticular lipid layer before and after host nest usurpation. The experiment documents that P. semenowi social parasites have an epicuticular hydrocarbon pattern which is very similar to that of their host but, after entering host colonies, parasites mimic the odour of the colonies they invade, to the point that they perfectly match the hydrocarbon profile peculiar to the colony they entered. However, both before and after host nest invasion, parasites show a tendency to possess diluted recognition cues with respect to their hosts.

The breeding biology of palm cockatoos (Probosciger aterrimus): a case of a slow life history

AbstractThe breeding of palm cockatoos Probosciger aterrimus was studied for 3 years from July 1999 to February 2002 in and around Iron Range National Park, Cape York Peninsula, Australia. Palm cockatoos were weakly seasonal breeders, with the peak of egg‐laying occurring in September; 41 breeding attempts were monitored at 28 nesting hollows. Nearly all (27/28) nests were in tropical savanna woodland and an average distance of 320 m to rainforest. Males defended about four nest sites, only a subset of which were used for breeding. The typical active nest tree was in a near‐vertical hollow with an opening that faced skywards; 62.1% of active nests were in living trees and the most common species of nest tree was Eucalyptus tetrodonta (48.3%). DNA fingerprinting revealed that some pairs reused the same nest hollow even when breeding attempts were separated by 1 or more years of no breeding activity, but that changes in hollow ownership also occurred. Nest usurpation, male territorial displays at the nest and evidence of interference competition by conspecifics suggest strong competition for nest sites, which is probably driven by variation in hollow quality and high investment in the nesting platform. Of active nests, 81% failed to produce a fledgling, thereby ranking the breeding success of palm cockatoos among the lowest reported for any species of parrot. They also invariably laid a single egg and seemed to breed infrequently, and thus they use an extremely slow life‐history strategy. We suggest that this slow life history makes palm cockatoos on Cape York Peninsula sensitive to environmental perturbations, with fire being the most probable threatening process.

Specific floater home ranges and prospective behaviour in the European starling, Sturnus vulgaris.

In many bird species, floaters are present on the breeding grounds in one or more years before they breed. There is increasing evidence that they have specific home ranges in which they search for information about current and future breeding opportunities. We investigated the role of prospecting in a migratory European starling (Sturnus vulgaris) population. Radio-tracking showed that male starling floaters use specific home range areas during the breeding period. Nest-box observations demonstrated that non-parental nest intrusion is common in the starling and that it is significantly more frequent during the nestling than during the incubation period. In addition, small groups of nest boxes were more likely to be occupied by starlings if they had been put up during the preceding breeding season. The results suggest that floaters try to acquire information about local breeding communities. One specific type of information may be the location of potential breeding sites.

Delayed timing as a strategy to avoid nest‐site competition: testing a model using data from starlings and flickers

European starlings (Sturnus vulgaris) introduced to North America compete with native cavity‐nesting birds for nest sites. I examined whether natural selection could favour a strategy of delayed nesting in a population of northern flickers (Colaptes auratus), a native woodpecker, to reduce overlap in breeding phenology with starling competitors. I developed a mathematical model based on reproductive parameters for a population of flickers from central British Columbia, Canada. On average, 7% of flicker nests each year were usurped by starlings; daily probabilities of takeover declined through the season but were relatively low (1–2%). Flickers laid between 3 and 13 eggs and there was a negative correlation between clutch size and date. The probability of renesting after nest failure also declined during the season, but renesting intervals (2–19 days) were not associated with female age, or stage of nest loss. The model suggested that costs of delaying reproduction would outweigh benefits of an early start except when the probability of nest usurpation is very high (>75%) early in the season and declines rapidly through the summer. Thus, early laying dates should be favoured especially in northern latitudes where breeding seasons are short.

Correlations between body size, defensive behaviour and reproductive success in male Little Blue Penguins Eudyptula minor: implications for female choice

Field studies exploring relationships among body size, defensive behaviour (including vocalizations) and reproductive success in male Little Blue Penguins Eudyptula minor were conducted to identify behavioural and physical attributes that might provide females or opponents with information on male quality. Head length provided a simple estimator of body size in both sexes. Nests defended by large males produced eggs and chicks earlier in the breeding season, and contained chicks that grew more quickly than chicks in nests defended by small males. In contrast, female body size did not affect any of the reproductive parameters we measured. The pitch of male defensive calls varied significantly with male size, so females (or opponents) could potentially gauge male size by assessing the calls. Large males were also more likely to respond vocally to simulated nest intrusions. As a result, by ‘keeping company’ with prospective partners early in the breeding season, females can obtain information about males that would allow them to select better partners and improve their own reproductive potential.

Alternative Mating Tactics in Sunfishes (Centrarchidae): A Mechanism for Hybridization?

Lepomis hybridization occurs frequently in natural systems. Previous investigations of sunfish hybridization have focused on courtship behavior of interspecific pairs. We observed spawning in Lepomis nesting colonies where interspecific nest intrusions occurred. Nesting male Lepomis microlophus (redear sunfish) attempted to fertilize eggs in the adjacent nests of spawning Lepomis megalotis (longear sunfish). Male sunfish commonly employ this reproductive tactic in the nests of conspecifics. When colonies contain more than one species, hybridization may occur through interspecific nest intrusion by males on adjacent nests.

Territorial behavior of Bearded Vultures in response to Griffon Vultures

Griffon Vultures (Gyps fulvus) are responsible for most cases of usurpation of nests of Bearded Vultures (Gypaetus barbatus). However, little is known about how both species interact during reproduction. We studied territorial behaviour during the breeding season in four Bearded Vulture pairs in the eastern Pyrenees of northeastern Spain. Frequency of agonistic behavior was positively correlated with Griffon Vulture colony size. However, no significantly higher frequency of aggressive interactions was found that suggested actual competition for nest sites between these species. Nonetheless, Bearded Vulture pairs maintained a continuous defence of the area immediately surrounding their nests throughout the breeding season. Our data suggest that the Bearded Vulture's territorial behavior was more closely associated with defence of breeding space than with specific defence of actual nest sites.

Queen-worker conflict over male production and the sex ratio in a facultatively polyandrous bumblebee, Bombus hypnorum: the consequences of nest usurpation

Evolutionary conflicts among social hymenopteran nestmates are theoretically likely to arise over the production of males and the sex ratio. Analysis of these conflicts has become an important focus of research into the role of kin selection in shaping social traits of hymenopteran colonies. We employ microsatellite analysis of nestmates of one social hymenopteran, the primitively eusocial and monogynous bumblebee Bombus hypnorum, to evaluate these conflicts. In our 14 study colonies, B. hypnorum queens mated between one and six times (arithmetic mean 2.5). One male generally predominated, fathering most of the offspring, thus the effective number of matings was substantially lower (1-3.13; harmonic mean 1.26). In addition, microsatellite analysis allowed the detection of alien workers, those who could not have been the offspring of the queen, in approximately half the colonies. Alien workers within the same colony were probably sisters. Polyandry and alien workers resulted in high variation among colonies in their sociogenetic organization. Genetic data were consistent with the view that all males (n = 233 examined) were produced by a colony's queen. Male parentage was therefore independent of the sociogenetic organization of the colony, suggesting that the queen, and not the workers, was in control of the laying of male-destined eggs. The population-wide sex ratio (fresh weight investment ratio) was weakly female biased. No evidence for colony-level adaptive sex ratio biasing could be detected.

Queen–worker conflict over male production and the sex ratio in a facultatively polyandrous bumblebee,Bombus hypnorum: the consequences of nest usurpation

AbstractEvolutionary conflicts among social hymenopteran nestmates are theoretically likely to arise over the production of males and the sex ratio. Analysis of these conflicts has become an important focus of research into the role of kin selection in shaping social traits of hymenopteran colonies. We employ microsatellite analysis of nestmates of one social hymenopteran, the primitively eusocial and monogynous bumblebeeBombus hypnorum, to evaluate these conflicts. In our 14 study colonies,B. hypnorumqueens mated between one and six times (arithmetic mean 2.5). One male generally predominated, fathering most of the offspring, thus the effective number of matings was substantially lower (1–3.13; harmonic mean 1.26). In addition, microsatellite analysis allowed the detection of alien workers, those who could not have been the offspring of the queen, in approximately half the colonies. Alien workers within the same colony were probably sisters. Polyandry and alien workers resulted in high variation among colonies in their sociogenetic organization. Genetic data were consistent with the view that all males (n = 233 examined) were produced by a colony’s queen. Male parentage was therefore independent of the sociogenetic organization of the colony, suggesting that the queen, and not the workers, was in control of the laying of male‐destined eggs. The population‐wide sex ratio (fresh weight investment ratio) was weakly female biased. No evidence for colony‐level adaptive sex ratio biasing could be detected.

Behaviour and success of sneaker males in the sand goby, Pomatoschistus minutus

In this study we investigated in laboratory conditions the presence of alternative reproductive tactics in the sand goby and describe proximate factors affecting their expression and success. We describe the reciprocal interactions of resident males, females, and sneaking males. The pre-spawning phase proved to be important for successful nest intrusions by sneakers. The number of sneakers had no effect on the frequency of successful intrusions. When small males had exclusive access to nest sites, they built a nest and courted females, showing a full behavioural repertoire. The intensity of courtship was, however, strongly positively correlated with body size. Using microsatellite DNA markers we assessed paternity shares of territorial and sneaker males in a subset of all replicates. Following successful nest intrusion sneaker males fertilised 5–10% of the eggs. Our interpretation of the results is that sneaking in the sand goby is a conditional tactic, one that is less successful than the normal nest guarding behaviour, at least for one spawning event.