Animal Behaviour

Limited influence of stream networks on the terrestrial movements of three wetland-dependent frog species

by Martin Westgate

with Don Driscoll and David Lindenmayer. In press with Biological Conservation.

Quantifying functional connectivity is essential for understanding factors that limit or promote animal dispersal in... more Quantifying functional connectivity is essential for understanding factors that limit or promote animal dispersal in fragmented landscapes. Topography is a major factor influencing the movement behaviour of many animal species, and therefore the extent of functional connectivity between habitat patches. For pond-breeding frogs, areas of low topographic relief (such as streams or drainage lines) offer damp microhabitats that can facilitate movement through otherwise dry landscapes. However, the extent of topographic bias of frog movements has rarely been quantified. We used a replicated study to compare captures in high- and low-relief transects, for three species from a pond-breeding frog community in southeastern Australia. We captured frogs significantly more often on low-relief transects. However, capture rates decreased with increasing distance from water at similar rates on both high-relief and low-relief transects, and we observed few differences between adult and juvenile movements. Our results suggest that although low-relief drainage lines are important for the pond-breeding frogs in question, ecologists and landscape managers should not discount the role of high-relief locations. Because low-relief drainage lines represent a low proportion of the pond margin, >90% of movements are likely to occur across high-relief locations. Therefore, for the species that we studied, buffer zones designed to conserve only hydrological networks would provide insufficient protection of frequently used pond margins, while drainage lines are unlikely to act as vital networks facilitating connectivity between breeding ponds. Our study suggests that movement across slopes may be most important for facilitating functional connectivity.

Aerial alarm calling by male fowl (Gallus gallus) reveals subtle new mechanisms of risk management

by K-lynn Smith

published in 'Animal Behaviour'

Alarm calling is a classic problem in evolutionary biology. Although a signaller may increase the likelihood of... more Alarm calling is a classic problem in evolutionary biology. Although a signaller may increase the likelihood of survival for group members, which typically include kin and mates, there are inherent risks associated with any behaviour that increases conspicuousness to predators. Callers can increase their indirect benefits by calling only in the presence of an appropriate audience and manage concomitant costs by judicious investment. Possible tactics for controlling costs include facultative variation in call structure and timing, as well as sensitivity to the environmental and social factors that predict personal vulnerability. We examined individual variation in the alarm-calling behaviour of male fowl in naturalistic social groups. Previous studies of cost management have focused on variation at the level of alarm call rate. We took advantage of recent advances in wireless sound recording and remote video monitoring to test for more subtle variation in signal structure and timing. These were then mapped onto individual mating success and moment-to-moment changes in environmental and social context. Results replicate the previous finding that alarm calling is sensitive to both social rank and recent mating success. In addition, we detected systematic variation in call structure as a function of personal vulnerability and proximity to a rival male. The frequency bandwidth of alarms was reliably influenced by degree of vigilance prior to calling, suggesting that this acoustic dimension reflects motivational state. Taken together, these results reveal several novel tactics for risk management, complementing those previously described at the level of gross variation in alarm-calling behaviour.

Multimodal signaling in fowl, Gallus gallus

by K-lynn Smith

Silent tidbitting in male fowl, Gallus gallus: a referential visual signal with multiple functions

by K-lynn Smith

Tactical multimodal signalling in birds: facultative variation in signal modality reveals sensitivity to social costs

by K-lynn Smith

Bilateral fractures of the coronoid processes: differential diagnosis of intra-oral gunshot trauma and scavenging using a sheep crania model

by Cathy Puskas

Understanding the Lion For Real

by Constantine Sandis

Final version forthcoming in (eds.) A. Marques & N. Venturinha, Knowledge, Language and Mind: Wittgenstein's Thought in Progress (Berlin: de Gruyter), 2012.

A longer book-length treatment will subsequently be published as Wittgenstein's Lion.


Comments welcome

Recurrent perseveration correlates with abnormal repetitive locomotion in adult mink but is not reduced by environmental enrichment

by Jamie Ahloy Dallaire

Dallaire JA, Meagher RK, Díez-León M, Garner JP, and Mason GJ. 2011. Behavioural Brain Research 224(2):213-222.

We analysed the relationship between abnormal repetitive behaviour (ARB), the presence/absence of environmental... more We analysed the relationship between abnormal repetitive behaviour (ARB), the presence/absence of environmental enrichment, and two types of behavioural disinhibition in farmed American mink, Neovison vison. The first type, recurrent perseveration, the inappropriate repetition of already completed responses, was assessed using three indices of excessive response repetition and patterning in a bias-corrected serial two-choice guessing task. The second type, disinhibition of prepotent responses to reward cues, a form of impulsivity, was tested in a locomotive detour task adapted from primate reaching tasks: subjects were required to walk around, rather than directly into, a transparent barrier behind which food was visible. In older adult females, recurrent perseveration positively predicted pre-feeding abnormal repetitive locomotion (ARL) in Non-enriched housing. High-ARL subjects also performed repeated (same-choice) responses more rapidly than low-ARL animals, even when statistically controlling for alternated (different-choice) response latency. Mink performed much less ARL following transfer to Enriched housing, but there was no corresponding change in recurrent perseveration. Thus, elevated recurrent perseveration is not sufficient for frequent ARL; and while captive environments do determine ARL frequency, in mink, they do not necessarily do so by modifying levels of perseveration. Disinhibition of prepotent responses to reward cues, meanwhile, did not predict ARL. In a separate sample of differentially housed young adults, neither type of behavioural disinhibition predicted ARL, and again, whether or not housing was enriched did not affect behavioural disinhibition despite affecting ARL. Thus, the relationship between recurrent perseveration and ARB may only develop with age; longitudinal studies are now required for confirmation.

Murid stress odours: a review and a 'low tech' method of collection

by Jamie Ahloy Dallaire

Mason G, Dallaire J, and Ware N. 2009. Animal Welfare 18(3):301-310.

Stress cues can affect the welfare of animals in close proximity and are possibly useful non-invasive indicators of... more Stress cues can affect the welfare of animals in close proximity and are possibly useful non-invasive indicators of the emitters' welfare. To facilitate their study in murids, we tested whether rats' stress odours could be collected and stored using an enfleurage-type technique. 'Donor' rats were individually exposed to a compound stressor (carried circa 75 m inside a novel container, then euthanised with rising carbon dioxide) while on blotting paper dotted with melted vegetable lard. These sheets were sealed, left at room temperature for 2-5 h, and then 'bioassayed' by a blind observer for their effects on conspecifics. Compared with control sheets (exposed to unstressed rats, to CO₂ alone, or untreated), stress-exposed sheets significantly affected the unconditioned behaviour of 16 pairs of detector rats trained to enter an arena from their home cage to obtain sucrose. When used to line this arena, the stress-exposed sheets significantly increased: i) rats' latencies to eat, to place front feet into, and to completely step into the arena and ii) shuttling movements between arena and home cage. These pilot data thus suggest that odours produced by stressed rats can be simply and successfully collected and stored for several hours, though certain potential confounds (eg urine volume) may conceivably be alternative explanations for the observed effects. Future work should control for urine volume, and assess whether fat is needed for optimal odour absorption by paper and for how long sheets can be stored at various temperatures. Much fundamental work is also still needed on the nature, functions, and sources of stress odours.

Middle-aged mice with enrichment-resistant stereotypic behaviour show reduced motivation for enrichment

by Jamie Ahloy Dallaire

Tilly SLC, Dallaire J, and Mason GJ. 2010. Animal Behaviour 80(3):363-373.

For captive animals, living in barren conditions leads to stereotypic behaviour that is hard to alleviate using... more For captive animals, living in barren conditions leads to stereotypic behaviour that is hard to alleviate using environmental enrichment. This resistance to enrichment is often explained via mechanisms that decouple abnormal behaviour from current welfare, such as ‘establishment’: a hypothetical process whereby repetition increases behaviour’s predictability and resistance to change. If such hypotheses are correct, then animals with enrichment-resistant stereotypic behaviour should still find enrichments rewarding. Alternatively, this behaviour could reflect a failure to improve welfare: plausible because age and chronic stress increase neophobia and anhedonia. If this hypothesis is correct, animals with enrichment-resistant stereotypic behaviour should value enrichments less than conspecifics. We tested these hypotheses using C57BL/6 mice, Mus musculus, aged 10–11 and 6–7 months, raised in barren laboratory cages. We observed their behaviour in both these and large enriched cages. Enrichment was more effective on the younger animals. However, contrary to ideas about establishment, the spontaneous predictability of stereotypic behaviour did not increase with age; nor was enrichment less effective on more predictable or time-consuming forms. We assessed the reward value of enriched cages by allowing access via progressively weighted doors (maximum weight pushed corresponding to peak motivation). In older mice, those individuals whose stereotypic behaviour was least reduced by enrichment were also the least motivated to gain access to enrichment. This suggests that the welfare of middle-aged-animals, as well as their stereotypic behaviour, is harder to improve using environmental enrichment.

The influence of predator regime on the behaviour and mortality of a freshwater amphipod, Gammarus pulex

by Johan Ahlgren

2011 Hydrobiologia, Co-authored with Kajsa Åbjörnsson and Christer Brönamrk

A rule-of-thumb based on social affiliation explains collective movements in desert baboons

by Cedric Sueur

Selective mimetism at departure in collective movements of Macaca tonkeana: an experimental and theoretical approach

by Cedric Sueur

From the first intention movement to the last joiner: macaques combine mimetic rules to optimize their collective decisions

by Cedric Sueur

Group decision-making in chacma baboons: leadership, order and communication during movement

by Cedric Sueur

Soulsbury, C.D., Alatalo, R.V., Lebigre, C. & Siitari, H. (2012) Restrictive mate choice criteria causes age-specific inbreeding in female black grouse Tetrao tetrix. Animal Behaviour.

by Carl Soulsbury

Online early

Inbreeding is generally rare in large, natural populations yet mate choice often appears to be random with respect to... more Inbreeding is generally rare in large, natural populations yet mate choice often appears to be random with respect to kinship. This suggests that the risks of inbreeding may be small because passive mechanisms of inbreeding avoidance, for example dispersal, are effective at lowering inbreeding risk. Previous theoretical and empirical studies have assumed that the risks of inbreeding are constant over an individual's life span, but in the lek-breeding black grouse, inbreeding increases with female age. To determine whether inbreeding avoidance mechanisms are also age dependent, we generated four null models of random mate choice ranging from complete randomness to more biologically realistic mate choice criteria and compared these to 8 years of data on inbreeding levels at four different female age classes. We additionally tested whether mate fidelity decreased inbreeding risk. Observed inbreeding in female age classes 1, 2 or ≥3 were not significantly different from random, but was approximately 3.5 times higher in female age class ≥4. Alternative models using mate choice criteria showed no significant differences between observed and expected levels for any age class. Our results are in line with previous studies on noncooperatively breeding passerine birds, which indicate that mating is random with respect to kinship and that increased inbreeding in older females can be explained by reduced male availability caused by restrictive mate choice criteria. We also found that individuals that switched mates significantly increased relatedness to partners suggesting that mate fidelity may have evolved as an important passive inbreeding avoidance mechanism.

From Social Network (Centralized vs. Decentralized) to Collective Decision-Making (Unshared vs. Shared Consensus)

by Cedric Sueur

On the importance of body size in the colonisation of ephemeral resource patches by vagile consumers

by giorgio mancinelli

Intraspecific, size-dependent variation in the movement behaviour of a brackish-water isopod: a resource-free laboratory experiment

by giorgio mancinelli

Body mass-related shift in movement behaviour in the isopod Lekanesphaera hookeri (Isopoda, Flabellifera): A laboratory study

by giorgio mancinelli