Polygyny and nest site selection in the pied flycatcher

Nest site choice, and its influence on mating and breeding success were studied in a population of individually marked pied flycatchers (Ficedula hypoleuca) for 7 years. Some nest boxes were used more frequently than expected from random choice of nest site. Flycatchers bred more successfully in such attractive boxes, irrespective of whether the brood was attended by the male or not. Arriving males and females settled at boxes in descending order of attractiveness. Boxes accepted by females were more attractive than alternative boxes advertised simultaneously by males. Secondary nest boxes of polygynous males tended to be more attractive than boxes at which monogamous males displayed, without success, for secondary mates. Returning males with local breeding experience started to sing at nest boxes earlier in spring than first season males, settled at more attractive boxes, and mated polygynously more often. The results indicate that male mating success should be closely dependent on the male's ability to monopolize attractive nest sites.     

Inadvertent social information in breeding site selection of natal dispersing birds

Several species use the number of young produced as public information (PI) to assess breeding site quality. PI is inaccessible for synchronously breeding birds because nests are empty by the time the young can collect this information. We investigate if location cues are the next best source of inadvertent social information (ISI) used by young prospectors during breeding site choice. We experimentally deployed ISI as decoys and song playbacks of breeding males in suitable and sub-optimal habitats during pre- and post-breeding periods, and monitored territory establishment during the subsequent breeding season for a social, bobolink (Dolichonyx oryzivorus), and a more solitary species, Nelson's sharp-tailed sparrow (Ammodramus nelsoni). The sparrows did not respond to treatments, but bobolinks responded strongly to post-breeding location cues, irrespective of habitat quality. The following year, 17/20 sub-optimal plots to which bobolink males were recruited were defended for at least two weeks, indicating that song heard the previous year could exert a "carry-over attraction" effect on conspecifics the following year. Sixteen recruited males were natal dispersers, as expected when animals have little opportunity to directly sample their natal habitat quality. We suggest that differences in breeding synchronicity may induce an equivalent clinal distribution of ISI use.     

Kin selection and the evolution of social information use in animal conflict

Animals often use social information about conspecifics in making decisions about cooperation and conflict. While the importance of kin selection in the evolution of intraspecific cooperation and conflict is widely acknowledged, few studies have examined how relatedness influences the evolution of social information use. Here we specifically examine how relatedness affects the evolution of a stylised form of social information use known as eavesdropping. Eavesdropping involves individuals escalating conflicts with rivals observed to have lost their last encounter and avoiding fights with those seen to have won. We use a game theoretical model to examine how relatedness affects the evolution of eavesdropping, both when strategies are discrete and when they are continuous or mixed. We show that relatedness influences the evolution of eavesdropping, such that information use peaks at intermediate relatedness. Our study highlights the importance of considering kin selection when exploring the evolution of complex forms of information use.     

Artificial nest box use by the North Island saddleback: Effects of nest box design and mite infestations on nest site selection and reproductive success

Abstract

The pests and weeds that can affect conservation values in New Zealand are mostly introduced species, including 31 species of mammals, a small number of birds, a few fish and amphibians, an unknown number of invertebrate species (but particularly two wasps), and at least 75 introduced plants capable of permanently altering native ecosystems.     

Long-billed curlew nest site selection and success in the Intermountain West

Grassland birds have experienced steeper population declines between 1966 and 2015 than any other bird group on the North American continent, and migratory grassland birds may face threats in all stages of their annual cycle. The grassland-associated long-billed curlew (Numenius americanus) is experiencing population declines in regional and local portions of their North American breeding range. The nesting period is an important portion of the annual cycle when curlews may face demographic rate limitations from a suite of threats including predators and anthropogenic disturbance. We compared nest sites to random sites within breeding territories to examine nest site selection, and modeled correlates of nesting success for 128 curlew nests at 5 Intermountain West sites. Nest sites were 6 times more likely than random sites to be situated adjacent to existing cowpies. Additionally, curlews selected nest sites with shorter vegetation, and less bare ground, grass, and shrub cover than at random sites within their territories. Nest success varied widely among sites and ranged from 12% to 40% in a season with a mean of 27% for all nests during the 2015 and 2016 seasons. Higher nest success probability was associated with higher curlew densities in the area, greater percent cover of conspicuous objects (cowpies, rocks) near the nest, and higher densities of black-billed magpies (Pica hudsonia) and American crows (Corvus brachyrhynchos) at the site. We also found increased probability of nesting success with increased distance from a nest to the nearest potential perch in that territory. Given the central role of working lands to curlews in much of the Intermountain West, understanding limitations to nesting success in these diverse landscapes is necessary to guide adaptive management strategies in increasingly human-modified habitats. We suggest some grazing and irrigation practices already provide suitable nesting conditions for curlews, and others may require only minor temporal shifts to improve compatibility. © 2019 The Wildlife Society.     

State-dependent decisions in nest site selection by a web-building spider

Foraging decisions may reflect a trade-off between food intake and safety and can also be influenced by the animal's internal state. Foraging in the web-building spider Stegodyphus lineatus depends on a capture web associated with a retreat (the nest). The relocation of nests, including the take-over of conspecific nests, may be viewed as a foraing decision, which depends on risk of exposure, cost of silk production and hunger state. We investigated a possible state-dependent trade-off in nest site choice of S. lineatus spiderlings. The philopatric nature ofS. lineatus implies a high risk of encounters with potentially cannibalistic conspecifics and a potential loss of inclusive fitness because encountered conspecifics are likely to be kin. To test for state dependence of foraging decisions, we compared preferences of well-fed and hungry spiders for their own nests and those of siblings and nonsiblings. We expected satiated spiders to prefer their own to conspecific nests and hungry spiders to choose the risky option of a conspecific nest. SinceS. lineatus is less aggressive towards kin, we tested the ability of spiders to discriminate kin by silk-bound cues. Because of this reduced aggression, preference for kin nests should be safer than preference for nonkin nests. A strong preference for self-nests demonstrated self-recognition in well-fed spiders. However, neither well-fed nor hungry spiders discriminated between nests of siblings and nonsiblings. Well-fed spiders preferred self-nests to empty chambers, but showed no discrimination between nonself-nests and empty chambers. Hungry spiders showed a reduced preference for self-nests, suggesting that hunger elicits a more risky foraging strategy. A tendency of hungry spiders to adopt the nests of conspecific spiders may reflect a silk-saving strategy. We conclude that S. lineatus spiders show state-dependent decision making in nest site selection. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.     

Intraspecific nest parasitism in the Spotless Starling Sturnus unicolor

Intraspecific nest parasitism in two colonies of Spotless Starling Sturnus unicolor breeding in nestboxes was studied in central Spain from 1991 to 1994. Nests were monitored regularly and three criteria were used to detect nest parasitism: the appearance of more than one egg per day during the laying period of the host; the appearance of an egg after the start of incubation; eggs with unusual shape or pigmentation. The proportion of parasitized nests in first clutches (37%) was twice that of intermediate (19%) or second (20%) clutches in colony B, whereas parasitism occurred in first (35%) and intermediate (12%) but not in second clutches in colony A. Most clutches (52–70%) were parasitized during the host's laying period and received one parasitic egg. In 10% of the parasitized clutches in colony B, one of the host's eggs disappeared on the day the parasitic egg was added, suggesting that the parasitic female removed this egg. Although parasitism increased clutch size significantly, it led to a decrease in host breeding success, mainly through the removal of eggs and the loss of host nestlings and the survival of parasitic chicks. Observations suggested that parasitic females were young individuals without their own nests and/or those whose breeding attempt had been disrupted while laying in their own nest.     

Intraspecific nest parasitism in the European starling Sturnus vulgaris

Biochemical genetic markers were used along with conventional methods (abnormal laying sequence/clutch size, unusual egg shape/pigmentation) to identify intraspecific nest parasitism at two British nestbox colonies of the European starling. Between 11 and 37% of first clutches were parasitized during 1977–1979. Parasitic females probably comprised all of the following categories: (1) paired females contesting a nestbox occupied by another pair; (2) previously paired females who had laid a clutch but had been unsuccessful; (3) unpaired females who had copulated with males that already had a mate and nest site; and (4) ‘professional’ nest parasites who distributed at lest some of their eggs in one or more nests other than their own. Although parasitized nests had higher clutch sizes, parasitism led to fewer host young fledging per egg laid, mainly through the eviction of eggs and subsequent nest desertion. Number of parasitic young fledged per egg laid was highest when eggs were laid synchronously with the host, when host clutches were larger, or a smaller number of parasite eggs were added to a nest, thus favouring parasites that distribute their eggs amongst a number of nests. A greater pressure on nest sites may have accounted for the higher levels of parasitism at the Aberdeen colony and for the greater number of parasite eggs laid in a nest. Although most parasitic female starlings appeared to be much less successful than non-parasitic ones, nest parasitism in the starling might evolve directly when one or more of the following advantages are present. (1) There are no constraints on the number of eggs a female may lay but there are constraints on the number of young she may feed adequately. (2) Female survival is increased by having fewer or no eggs/young to care for. (3) Current feeding conditions favour the survival of more young than would be produced by the most common clutch size. Intraspecific nest parasitism is considered to be a first stage in the evolution of interspecific nest parasitism.     

Trade-offs in nest site selection in coastal populations of Lapwings Vanellus vanellus

In coastal populations of Lapwings Vanellus vanellus in southwestern Sweden, arable fields predominated as foraging habitat before laying. Females caught more large prey items on arable fields and shores than on pastures. Close to egg laying, females foraged mainly near their future nest sites. Arable land and pastures were used to a similar extent for nesting. We found no difference in nest predation between habitats. Egg volume varied among females and was correlated with wing-length, body mass and condition. Mean egg volume also was positively correlated with feeding time on arable land before laying. Pairs nesting on arable fields therefore generally produced larger eggs than those on pastures. The distances between nests and chick foraging areas, however, were significantly longer for birds nesting on arable land than for those on pastures. Moreover, in 2 of 3 years, the proportion of hatched chicks that survived until fledging was negatively correlated with this distance. There was no difference in chick survival between broods hatched on arable fields and pastures. We suggest that nest site selection and offspring production involve a trade-off between the benefits of nesting close to rich feeding grounds for adults and the costs of moving long distances between nest sites and chick-rearing areas.     

Spatial patterns of granivorous ant nest abundance and nest site selection in agricultural landscapes of Central Spain

Summary Patterns of abundance and site selection of granivorous ant nests were investigated in extensive cereal croplands of Central Spain. Nest densities and distributions were measured in two consecutive summers (1988 and 1989), together with habitat physiognomy and seed availability. Nest site selection patterns were analysed at two spatial scales (landscape and microhabitat) with respect to habitat physiognomy. Results indicate a very constant and predictable pattern of both nest abundance and nest site selection. Granivorous ant nests were most abundant in shrublands, and shrubby microsites were selected for nest placement. Croplands, and microsites with high covers of bare ground and litter, were avoided. These patterns were consistent between years despite a 1.7-fold increase in shrubland nest densities, that was attributed to the exceptionally dry winter between nest censuses. I suggest that winter survivorship of ant nests in the unploughed landscape units, and periodic ploughing in croplands, may be the main factors constraining granivorous ant densities in the landscape studied.     

Nest site selection and patterns of nest re-use in the Hooded Crow Corvus cornix

Capsule: Hooded Crows Corvus cornix selected nesting trees based on species, height, grouping and distance from an occupied house. Nest re-use was common and pairs that re-used old nests produced more fledglings than those that built a new nest.

Aims: To determine the features of trees that influenced whether they were used by Hooded Crows as nest sites, to establish what factors influenced nest re-use between years and to explore potential costs or benefits of nest re-use.

Methods: In a large area of Orkney, Scotland, the features of trees that contained a Hooded Crow nest were compared to those of trees where nests were absent. Patterns of nest re-use between years were examined in relation to the availability of alternative sites, previous nesting success and the number of equivalent options to the tree used previously within 200?m of this site.

Results: Hooded Crows favoured spruce and pine trees as nest sites, above the most locally abundant tree species, elder and willow. Preference for trees increased with tree height, local tree density and distance from occupied houses. Over half of the crows studied re-used an old nest when one was available and crows that re-used an old nest fledged more offspring than those that built a new nest. The likelihood of a new nest being built increased as the number of potential locations to build increased. Territories where a nest survived the winter were more likely to be reoccupied the following year than those where nests fell, while territories with fewer trees around the old site were most likely to be abandoned, suggesting that those were territories of lower quality.

Conclusions: Hooded Crows displayed strong preferences for nest sites that might favour nesting success by offering concealment, shelter and protection from ground-based predators. Nest re-use was common, especially when alternative sites were scarce, and appeared to facilitate greater reproductive output.     

Landscape effects on nest site selection and nest success of Northern Lapwing Vanellus vanellus in lowland wet grasslands

Capsule: Northern Lapwing Vanellus vanellus avoid nesting close to small woodland patches but nest predation rates do not vary with distance to woodland patches, either because risky areas are avoided or perceived nest predation risk does not reflect actual risk.

Aims: To explore the effects of woodland patches in wet grassland landscapes on nest distribution and success of Lapwings.

Methods: We quantified the effect of woodland patches on the distribution and outcome of Lapwing nests across four wet grassland sites by mapping nest distribution and monitoring nest outcomes.

Results: Lapwing nested significantly further from woods than expected by chance. Neither nest predation rates nor the probability of predation occurring at night (thus primarily mammalian predators) or day (primarily avian predators) varied in relation to distance from woodland patches.

Conclusions: High levels of nest and chick predation in wet grassland landscapes limit the capacity for breeding wader populations to be self-sustaining. Consequently, identifying manageable landscape features that influence predation rates is an important focus of conservation research. Lapwing avoid breeding close to woodland but, as nest predation rates do not vary with distance from woodland patches, their removal may increase the area of suitable nesting habitat but is unlikely to substantially influence productivity.     

Factors affecting nest site selection and nesting success in the Common Eider Somateria mollissima

Nesting site selection and nesting success in Common Eiders Somateria mollissima were studied over a 3-year period (1991–1993) in the Mast River delta (58^o24'N, 94^o24'W), 40 km east of Churchill, Manitoba, Canada. Eiders preferentially nested on islands that had incubating Lesser Snow Geese Anser caerulescens caerulescens on them; this effect was also seen between years on the same islands. Eiders which nested on islands with geese had a reduced chance of having eggs taken by predators during egg-laying and had a greater chance of hatching once incubation had begun, independent of the number of other eiders nesting on the island. The distance to a goose nest was less in nests which did not lose eggs prior to incubation than in those which did, but there was no difference in the distance to a goose nest in eider clutches which did or did not hatch. Artificial eider eggs placed closer to goose nests had a lower probability of being predated than those placed farther away. Nests on islands farther up the river and farther from the mainland had higher nesting success, presumably because these nesting islands were inaccessible to Arctic Foxes Alopex lagopus.     

Conspecific attraction and nest site selection in a nomadic species,the zebra finch

Conspecific nesting density affects many aspects of breeding biology, as well as habitat selection decisions. However, the large variations in breeding density observed in many species are yet to be fully explained. Here, we investigated the settlement patterns in a colonial species with variable breeding density and where resource distribution could be manipulated. The zebra finch, Taeniopygia guttata, is a classic avian model in evolutionary biology but we know surprisingly very little about nest site selection strategies and nesting densities in this species, and in fact, in nomadic species in general. Yet, important determinants of habitat selection strategies, including temporal predictability and breeding synchrony, are likely to be different in nomadic species than in the non‐nomadic species studied to date. Here, we manipulated the distribution of nesting sites (by providing nest boxes) and food patches (feeders) to test four non‐exclusive habitat selection hypotheses that could lead to nest aggregation: 1) attraction to resources, 2) attraction to breeding conspecifics, and 3) attraction to successful conspecifics and 4) use of private information (i.e. own reproductive success on a site). We found that wild zebra finches used conspecific presence and possibly reproductive success, to make decisions over where to locate their nests, but did not aggregate around water or food within the study areas. Moreover, there was a high degree of inter‐individual variation in nesting density preference. We discuss the significance of our results for habitat selection strategy in nomadic species and with respect to the differential selection pressures that individuals breeding at different densities may experience.