Manipulating Individual Decisions and Environmental Conditions Reveal Individual Quality in Decision-Making and Non-Lethal Costs of Predation Risk

Received: July 6, 2012; Accepted: November 13, 2012; Published: December 13, 2012

SOCIAL INFORMATION USE IS A PROCESS ACROSS TIME, SPACE, AND ECOLOGY, REACHING HETEROSPECIFICS

Decision making can be facilitated by observing other individuals faced with the same or similar problem, and recent research suggests that this social information use is a widespread phenomenon. Implications of this are diverse and profound: for example, social information use may trigger cultural evolution, affect distribution and dispersal of populations, and involve intriguing cognitive traits. We emphasize here that social information use is a process consisting of the scenes of (1) event, (2) observation, (3) decision, and (4) consequence, where the initial event is a scene in such a process of another individual. This helps to construct a sound conceptual framework for measuring and …

Physiological stress does not increase with urbanization in European blackbirds: Evidence from hormonal, immunological and cellular indicators

Urbanization changes the landscape structure and ecological processes of natural habitats. While urban areas expose animal communities to novel challenges, they may also provide more stable environments in which environmental fluctuations are buffered. Species´ ecology and physiology may determine their capacity to cope with the city life. However, the physiological mechanisms underlying organismal responses to urbanization, and whether different physiological systems are equally affected by urban environments remain poorly understood. This severely limits our capacity to predict the impact of anthropogenic habitats on wild populations. In this study, we measured indicators of physiological…

Predator proximity as a stressor in breeding flycatchers: mass loss, stress protein induction, and elevated provisioning.

We investigated the physiological and behavioral consequences for prey breeding at different distances from a nesting predator. In a natural setting, Pied Flycatchers (Ficedula hypoleuca) made territory location decisions relative to established Sparrowhawk (Accipiter nisus) nests. From female flycatchers attending nests at different distances from Sparrowhawk nests, we measured body mass, blood stress protein (HSP60 and HSP70), and plasma immunoglobulin levels at the beginning (initial) and end (final) of the flycatcher breeding cycle, and provisioning rates during the nestling phase. We found that individuals breeding in closer proximity to Sparrowhawk nests, under higher perceived predat…

Mammalian nest predator feces as a cue in avian habitat selection decisions

Breeding habitat selection is expected to be adaptive. Animals should respond to strong agents of natural selection, such as expected offspring mortality due to nest predators, in their settlement decisions. In birds, mammalian nest predators are a significant mortality source and birds are known to respond to their presence. However, the mechanism used by birds to perceive mammalian nest predators and estimate the nest predation risk remains unknown, in particular at larger spatial scales while comparing potential breeding habitat patches. We experimentally tested whether the farmland bird community can detect and perceive cues of a mammalian nest predator (urine and feces), and how this p…

Breeding near heterospecifics as a defence against brood parasites: can redstarts lower probability of cuckoo parasitism using neighbours?

Breeding habitat choice based on the attraction to other species can provide valuable social information and protection benefits. In birds, species with overlapping resources can be a cue of good quality habitats; species with shared predators and/or brood parasites can increase joint vigilance or cooperative mobbing, while raptors may provide a protective umbrella against these threats. We tested whether the migratory common redstart (Phoenicurus phoenicurus) is attracted to breed near active nests of the great tit (Parus major), a keystone-information source for migrant passerine birds, or a top predator, the northern goshawk (Accipiter gentilis). This system is unique to test these quest…

Is it interspecific information use or aggression between putative competitors that steers the selection of nest-site characteristics? A reply to Slagsvold and Wiebe

Maternally‐transferred thyroid hormones and life‐history variation in birds

1. In vertebrates, thyroid hormones (THs) play an important role in the regulation of growth, development, metabolism, photoperiodic responses and migration. Maternally transferred THs are important for normal early-phase embryonic development when embryos are not able to produce endogenous THs. Previous studies have shown that variation in maternal THs within the physiological range can influence offspring phenotype. 2. Given the essential functions of maternal THs in development and metabolism, THs may be a mediator of life-history variation across species. 3. We tested the hypothesis that differences in life histories are associated with differences in maternal TH transfer across species…

Interspecific information on predation risk affects nest site choice in a passerine bird

Abstract Background Breeding site choice constitutes an important part of the species niche. Nest predation affects breeding site choice, and has been suggested to drive niche segregation and local coexistence of species. Interspecific social information use may, in turn, result in copying or rejection of heterospecific niche characteristics and thus affect realized niche overlap between species. We tested experimentally whether a migratory bird, the pied flycatcher Ficedula hypoleuca, collects information about nest predation risk from indirect cues of predators visiting nests of heterospecific birds. Furthermore, we investigated whether the migratory birds can associate such information w…

Is it interspecific information use or aggression between putative competitors that steers the selection of nest-site characteristics? A reply to Slagsvold and Wiebe

A growing number of studies have demonstrated that heterospecific individuals with overlapping resource needs – putative competitors – can provide information to each other that improves the outcomes of decisions. Our studies using cavity nesting resident tits (information provider) and migratory flycatchers (Ficedula spp., information user) have shown that selective interspecific information use (SIIU) can result in flycatchers copying and rejecting the apparent nest-site feature preferences of tits, depending on a perceivable fitness correlate (clutch size) of the tits. ese, and other results on the interspecific information use, challenge the predictions of traditional theory of species coexi…

Risk taking in natural predation risk gradients: support for risk allocation from breeding pied flycatchers

Predation risk is vital in foraging decisions because activity involves some degree of risk. In a natural setting, predation risk shows temporal variation, which has been largely neglected in antipredator studies. We tested a prediction of the risk allocation hypothesis in which allocation to antipredator behaviours will depend on temporal variation in perceived risk. Individuals are predicted to allocate heightened antipredator behaviours to brief infrequent periods of high risk, but with increasing frequency of high-risk periods, individuals will invest less in these behaviours. We tested this prediction using pied flycatchers, Ficedula hypoleuca , breeding at different distances from spa…

Predation as a landscape effect: the trading off by prey species between predation risks and protection benefits.

1. Predators impose costs on their prey but may also provide benefits such as protection against other (e.g. nest) predators. The optimal breeding location in relation to the distance from a nesting raptor varies so as to minimize the sum of costs of adult and nest predation. We provide a conceptual model to account for variation in the relative predation risks and derive qualitative predictions for how different prey species should respond to the distance from goshawk Accipiter gentilis nests. 2. We test the model predictions using a comprehensive collection of data from northern Finland and central Norway. First, we carried out a series of experiments with artificial bird nests to test if…

Predator encounters have spatially extensive impacts on parental behaviour in a breeding bird community.

Predation risk has negative indirect effects on prey fitness, partly mediated through changes in behaviour. Evidence that individuals gather social information from other members of the population suggests that events in a community may impact the behaviour of distant individuals. However, spatially wide-ranging impacts on individual behaviour caused by a predator encounter elsewhere in a community have not been documented before. We investigated the effect of a predator encounter (hawk model presented at a focal nest) on the parental behaviour of pied flycatchers ( Ficedula hypoleuca ), both at the focal nest and at nearby nests different distances from the predator encounter. We show tha…

Data from: Predator encounters have spatially extensive impacts on parental behaviour in a breeding bird community

Predation risk has negative indirect effects on prey fitness, partly mediated through changes in behaviour. Evidence that individuals gather social information from other members of the population suggests that events in a community may impact the behaviour of distant individuals. However, spatially wide-ranging impacts on individual behaviour caused by a predator encounter elsewhere in a community have not been documented before. We investigated the effect of a predator encounter (hawk model presented at a focal nest) on the parental behaviour of pied flycatchers (Ficedula hypoleuca), both at the focal nest and at nearby nests different distances from the predator encounter. We show that n…