lable at ScienceDirect

Animal Behaviour 77 (2009) 769–770

Contents lists avai

Animal Behaviour

journal homepage: www.elsevier .com/locate/yanbe

In Focus

Featured Articles in This Month’s Animal Behaviour

Figure 1. Male collared flycatcher. Male courtship behaviour was stimulated byplacing a caged female on the top of the nestbox. A piece of white paper was attachedbelow the entrance hole to provide novelty and measure how the focal male changedits behaviour in the altered situation. Photo: Miklos Laczi.

Why a Bird in the Hand may not always be worth Two in the Bush.

Reality shows such as ‘Big Brother’ and ‘Survivor’ like to suggestthey are conducting ‘social experiments’, investigating how peoplecope in confined quarters or unfamiliar situations. The fact that thecontestants in these shows tend to be, for the most part, attention-seeking, fame-hungry wannabes tends to undermine these morelofty goals, but, of course, there’s heavy self-selection going on:for the most part, only attention-seeking, fame-hungry wannabesput themselves forward for such programmes. The issues raisedby reality television may seem very far from studies of animalbehaviour, but in this month’s issue, Laszlo Garamszegi, MarcelEens and Janos Torok show that similar problems of ‘self-selection’could have implications for the field of animal personality or‘behavioural syndrome’ research (pp. 803–812). Specifically, theysuggest that personality-related differences in the ease of trappingindividuals could mean that some personality types are more likelyto make it into the laboratory than others.

To show this, the initial step was to assess the behaviour of wildcollared flycatchers in terms of traits related to boldness andshyness under three different conditions. In the first, novelty wasintroduced into the birds’ environment (by placing a piece of whitepaper on their nestboxes, see Fig. 1). Garamszegi and colleaguesthen measured the birds’ exploratory behaviour. Specifically, theymeasured the intensity of courtship behaviour that the male birdsshowed towards females under these novel conditions, andcompared it to the intensity of courtship that the males had shownunder natural conditions. Second, the birds were presented witha strange male bird and their aggressive responses towards itwere recorded. Finally, the birds’ tendency to take risks in the pres-ence of a potential predator (one of the experimenters walkingthrough the birds’ territory) was measured. These findings, inthemselves, make this an interesting and novel study as mostpersonality research to date has been performed on great tits andin captivity. Demonstrating the existence of behavioural syndromesin another species, with a completely different ecology, and underwild conditions to boot, is immensely valuable.

The behavioural tests established that birds that were exploratoryin the novel environment also tended to behave aggressively to othermales, and they were also more likely to take a high risk whena potential predator was present. Like great tits, collared flycatchersdisplay consistent personality traits and can be reliably classified asbeing either bold or shy. The relationship between the three traitswas not perfect, however. In particular, although there was a strongrelationship between exploratory behaviour in the courtship contextand risk taking, the relationship between aggression and risk takingwas much weaker. This indicates that additional contextual factors

0003-3472/$38.00 � 2009 The Association for the Study of Animal Behaviour. Publishedoi:10.1016/j.anbehav.2009.02.001

may influence the expression of individual traits. Fortune may notalways favour the bold, for example. Accordingly, it will pay to besensitive to the particular demands of certain social situations andfor traits to be expressed in context-dependent fashion.

When Garamszegi and colleagues then attempted to capturethe birds in their population, in the second part of their study,they found that the bolder birds were much easier to catch, whileshy birds proved to be much more elusive. Sampling from wild birdpopulations for subsequent investigations of bird personalities oreven other behavioural or physiological traits therefore needs tobe done cautiously and with sensitivity to the likelihood of

d by Elsevier Ltd. All rights reserved.

In Focus / Animal Behaviour 77 (2009) 769–770770

capturing only certain kinds of birds. Unlike reality TV, a skewedsample is not good for the business of research. Simply recognizingthat personality traits can influence the likelihood of capture,however, means that researchers can work to ensure that theydon’t miss out on the shyer types that might otherwise get over-looked.

Louise BarrettExecutive Editor

Figure 2. A male wolf spider, Schizocosa ocreata. Photo: George Uetz.

Sex and Death: how Wolf Spiders improve the Chances of theFormer, while Avoiding the Latter

Quick recognition and response to predator approach is a keyelement of animal survival. Hiding from a predator takes timeaway from other essential tasks, such as feeding, so predator recog-nition needs to be highly selective, as well. Konrad Lorenz’s famous,though controversial, experiments with geese first brought atten-tion to this question. Lorenz suggested that geese respond toa hawk shape in the sky above them as a predator, but not to a gooseshape. To Lorenz, this supported the idea that simple, instinctual,stimulus filtering could shape important behavioural responses.

Some activities, such as mating displays, may put individuals atparticular risk for predation. Signals designed to attract a mate mayvery well attract a predator, instead. Animals in situations withboth large benefits, such as mating, and high risks, such as deathfrom predation, need to strike a risky balance. An overly timidanimal that isn’t selective in its responses to distractions maylose opportunities to mate, but ignoring a predator’s approach isequally a mistake.

In this issue, Lohrey et al. (pp. 813–821) explore predator recog-nition by wolf spiders (Fig. 2). In an interesting parallel to the Lor-enz experiments, they focus on cues that might reveal the approachof a bird. Avian predators are an important threat to spiders, and itis reasonable to hypothesize that evolutionary pressures in a systemof avian predators and spider prey might have affected both pred-ator and prey. Birds should have evolved to conceal cues that mightexpose their presence, while spiders should have heightenedsensory sensitivity and strategies for stimulus filtering to allowquick identification of approaching birds.

Spiders have two tactics at hand when a predator approaches.First, they can freeze; this stops any signals that might have beenattracting the predator. Because spiders often blend into their back-ground, freezing may make them very difficult to find. Alterna-tively, the spider can flee; with this response, the obvious

advantage of seeking shelter is counterbalanced by perhaps beingmade more obvious by moving.

The courting wolf spiders studied by Lohrey and her colleagueswere presented with stimuli that mimicked the vibration caused bythe tapping of a bird’s beak on the ground, a bird call or the visualimage (shadow) of a bird. Spiders froze in response to vibration andsound, but fled from a visual image. Further testing showed thatsound is perceived as vibration in the substrate, helping to explainwhy these two stimuli gave the same result. The spiders ignoredirrelevant control stimuli and resumed courtship. Vibration andsound may indicate that a bird is very close, so freezing is theonly real option. Visual detection of a bird can occur over greaterdistances, giving the spider time to move out of sight.

These results support the overall hypothesis that sharedevolutionary history with avian predators has shaped theresponses of wolf spiders; they have the ability to filter cuesassociated with the approach of a bird from other incoming infor-mation, and to respond in ways that increase their survival chan-ces. This study adds nicely to our overall understanding of thebalance between risk and benefit when animals producecourtship advertisements.

Michael BreedExecutive Editor