64 research outputs found
An individual-based profitability spectrum for understanding interactions between predators and their prey
There is confusion in the animal behaviour literature over the use of the terms âtoxicityâ and âunpalatabilityâ, which are commonly used interchangeably when describing the function of chemical compounds in prey, although these terms describe very different functions. Toxic chemicals cause fitness-reducing harm, whereas unpalatability provides aversive taste but no reduction in fitness. Furthermore, chemical defences are only one aspect of prey profitability. We argue that if predators are maximizing fitness, all prey can be described in terms of their costs and benefits to predators across all currencies, giving each prey item a positive or negative position on a âprofitability spectrumâ. Adaptively foraging predators should be selected to eat only prey with a positive profitability. The context of each predatorâprey encounter also alters the profitability of the prey. Given that profitability is a function of the current state of both the predator and the prey individuals, we explain why it should be considered to be an attribute of a particular encounter, in contrast to its present usage as an attribute of a prey species. This individual-centred perspective requires researchers to investigate, through both theoretical models and empirical studies, the complex conditions in which predators and prey meet in real life
Social network centrality predicts dietary decisions in a wild bird population
How individuals balance costs and benefits of group living remains central to understanding sociality. In relation to diet, social foraging provides many advantages but also increases competition. Nevertheless, social individuals may offset increased competition by broadening their diet and consuming novel foods. Despite the expected relationships between social behavior and dietary decisions, how sociality shapes individualsâ novel food consumption remains largely untested in natural populations. Here, we use wild great tits to experimentally test how sociality predicts dietary decisions. We show that individuals with more social connections have higher propensity to use novel foods compared to socially peripheral individuals, and this is unrelated to neophobia, observations, and demographic factors. These findings indicate sociable individuals may offset potential costs of competition by foraging more broadly. We discuss how social environments may drive behavioral change in natural populations, and the implications for the causes and consequences of social strategies and dietary decisions
Badger territoriality maintained despite disturbance of major road construction
Publication history: Accepted - 19 August 2021; Published - 3 September 2021.Road ecology has traditionally focused on the impact of in-situ and functional roads on wildlife.
However, road construction also poses a major, yet understudied, threat and the implications
for key aspects of animal behaviour are unknown. Badgers (Meles meles) have
been implicated in the transmission of tuberculosis to cattle. There are concerns that environmental
disturbances, including major road construction, can disrupt badger territoriality,
promoting the spread of the disease to cattle. To address these knowledge gaps the ranging
behaviour of a medium-density Irish badger population was monitored using GPS-tracking
collars before, during, and after a major road realignment project that bisected the study
area. We estimated badgersâ home range sizes, nightly distances travelled, and the distance
and frequency of extra-territorial excursions during each phase of the study and quantified
any changes to these parameters. We show that road construction had a very limited
effect on ranging behaviour. A small increase in nightly distance during road construction
did not translate into an increase in home range size, nor an increase in the distance or frequency
of extra-territorial excursions during road construction. In addition, suitable mitigation
measures to prevent badger deaths appeared to ensure that normal patterns of ranging
behaviour continued once the new road was in place. We recommend that continuous badger-
proof fencing be placed along the entire length of new major roads, in combination with
appropriately sited underpasses. Our analysis supports the view that road construction did
not cause badgers to change their ranging behaviour in ways likely to increase the spread of
tuberculosis.AG was supported by a PhD scholarship
provided by the Department of Agriculture, Food
and the Marine, Ireland. This project was
conceived, carried out and funded by the
Department of Agriculture, Food and the Marine,
Ireland, and the National Parks and Wildlife
Service, Ireland
An investigation of Mycobacterium bovis and helminth coinfection in the European badger Meles meles
We investigated the relationship between the presence of helminth parasites in European badgers, and their tuberculosis (TB) status, culled as part of the bovine TB eradication programme in Ireland. Data on the worm burden or faecal egg or larval count was available for all helminth taxa recorded. Lymph node tissue samples were taken from the badgers and tested for TB. We then explored the correlation, in full-grown badgers, between the likelihood of M. bovis infection and both the prevalence and burden of certain helminth species. Specifically, our analyses focused upon the gastrointestinal species, Uncinaria criniformis and Strongyloides spp. We found that male badgers were more likely to have TB than female badgers, and that badgers infected with U. criniformis or Strongyloides spp. were more likely to have TB than badgers without such helminth infections. There was a suggestion that badgers with higher U. criniformis worm burdens were more likely to have TB than those with lesser burdens. Although our sampling protocols did not allow us to determine which infection came first, it strongly suggests that once badgers are infected with either gastrointestinal helminths or TB, they are likely to become coinfected. As Ireland works towards a national TB-free status, it will be important to appreciate the implications of such coinfection
AVONET: Morphological, ecological and geographical data for all birds
Functional traits offer a rich quantitative framework for developing and testing theories in evolutionary biology, ecology and ecosystem science. However, the potential of functional traits to drive theoretical advances and refine models of global change can only be fully realised when species-level information is complete. Here we present the AVONET dataset containing comprehensive functional trait data for all birds, including six ecological variables, 11 continuous morphological traits, and information on range size and location. Raw morphological measurements are presented from 90,020 individuals of 11,009 extant bird species sampled from 181 countries. These data are also summarised as species averages in three taxonomic formats, allowing integration with a global phylogeny, geographical range maps, IUCN Red List data and the eBird citizen science database. The AVONET dataset provides the most detailed picture of continuous trait variation for any major radiation of organisms, offering a global template for testing hypotheses and exploring the evolutionary origins, structure and functioning of biodiversity.Fil: Tobias, Joseph A.. Imperial College London; Reino Unido. University of Oxford; Reino UnidoFil: Sheard, Catherine. University of Oxford; Reino Unido. University of Bristol; Reino UnidoFil: Pigot, Alex L.. University of Oxford; Reino Unido. University College London; Estados UnidosFil: Devenish, Adam J. M.. Imperial College London; Reino UnidoFil: Yang, Jingyi. Imperial College London; Reino UnidoFil: Sayol, Ferran. University College London; Estados UnidosFil: Neate Clegg, Montague H. C.. University of Oxford; Reino Unido. University of Utah; Estados UnidosFil: Alioravainen, Nico. University of Oxford; Reino Unido. Natural Resources Institute Finland; FinlandiaFil: Weeks, Thomas L.. Imperial College London; Reino Unido. Natural History Museum; Reino UnidoFil: Barber, Robert A.. Imperial College London; Reino UnidoFil: Walkden, Patrick A.. Imperial College London; Reino Unido. Natural History Museum; Reino UnidoFil: MacGregor, Hannah E. A.. University of Oxford; Reino Unido. University of Bristol; Reino UnidoFil: Jones, Samuel E. I.. University of Oxford; Reino Unido. University of London; Reino UnidoFil: Vincent, Claire. OrganizaciĂłn de Las Naciones Unidas; ArgentinaFil: Phillips, Anna G.. Senckenberg Biodiversity And Climate Research Centre; AlemaniaFil: Marples, Nicola M.. Trinity College; Estados UnidosFil: Montaño Centellas, Flavia A.. Universidad Mayor de San AndrĂ©s; Bolivia. University of Florida; Estados UnidosFil: Leandro Silva, Victor. Universidade Federal de Pernambuco; BrasilFil: Claramunt, Santiago. University of Toronto; CanadĂĄ. Royal Ontario Museum; CanadĂĄFil: Darski, Bianca. Universidade Federal do Rio Grande do Sul; BrasilFil: Freeman, Benjamin G.. University of British Columbia; CanadĂĄFil: Bregman, Tom P.. University of Oxford; Reino Unido. Future-Fit Foundation; Reino UnidoFil: Cooney, Christopher R.. University Of Sheffield; Reino UnidoFil: Hughes, Emma C.. University Of Sheffield; Reino UnidoFil: Capp, Elliot J. R.. University Of Sheffield; Reino UnidoFil: Varley, ZoĂ« K.. University Of Sheffield; Reino Unido. Natural History Museum; Reino UnidoFil: Friedman, Nicholas R.. Okinawa Institute of Science and Technology Graduate University; JapĂłnFil: Korntheuer, Heiko. Johannes Gutenberg Universitat Mainz; AlemaniaFil: Corrales Vargas, Andrea. Universidad Nacional de Costa Rica; Costa RicaFil: GarcĂa, Natalia Cristina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin
AVONET: morphological, ecological and geographical data for all birds
Functional traits offer a rich quantitative framework for developing and testing theories in evolutionary biology, ecology and ecosystem science. However, the potential of functional traits to drive theoretical advances and refine models of global change can only be fully realised when speciesâlevel information is complete. Here we present the AVONET dataset containing comprehensive functional trait data for all birds, including six ecological variables, 11 continuous morphological traits, and information on range size and location. Raw morphological measurements are presented from 90,020 individuals of 11,009 extant bird species sampled from 181 countries. These data are also summarised as species averages in three taxonomic formats, allowing integration with a global phylogeny, geographical range maps, IUCN Red List data and the eBird citizen science database. The AVONET dataset provides the most detailed picture of continuous trait variation for any major radiation of organisms, offering a global template for testing hypotheses and exploring the evolutionary origins, structure and functioning of biodiversity
Odour and colour as cues for taste-avoidance learning in domestic chicks
In addition to being visually conspicuous, many chemically defended insects also produce olfactants when attacked. These olfactants may constitute âwarning odoursâ, comparable in their effects to warning colours. This hypothesis was tested by examining the ability of two odours, almond and vanilla, to act as cues for avoidance of quinine-flavoured water in domestic chicks,Gallus gallus domesticusIn experiment 1, chicks were trained to avoid familiar-coloured quinine solution, novel-coloured solution, or novel-smelling solution. When the novel smell was almond it enhanced the rate of avoidance learning, as did the novel colour cue; but vanilla odour had no effect on rate of learning. In experiment 2, chicks were trained to avoid quinine solution that was paired with a compound cue involving both colour and odour. They were then tested in extinction with both cues, either cue alone, or neither cue. When the odour cue was almond it overshadowed the colour cue: chicks that had learned to avoid almond-smelling quinine solution of a particular colour subsequently avoided almond-smelling water and drank water that did not smell of almond, regardless of its colour. Vanilla odour, by contrast, exerted no control over behaviour when paired with a colour cue during acquisition. In experiment 3, chicks were trained to discriminate palatable from quinine-flavoured water when the latter was distinguished solely by an odour cue. The discrimination was learned more readily when the cue was almond than when it was vanilla; and a memory test revealed significant avoidance of almond odour, but not of vanilla, after 24 h. We conclude that odours can act as discriminative stimuli for taste-avoidance learning in birds and that they can sometimes exert more powerful control over behaviour than do visual cues. However, not all odours are equally efficacious. The results are discussed in relation to aposematism and mimicry
Effects of novel colour and smell on the response of naive chicks towards food and water
No description supplie
Annual survival rate and mean life-span of lemon-bellied white-eyes Zosterops chloris flavissimus on Kaledupa island, Wakatobi, south-east Sulawesi, Indonesia
Volume: 28Start Page: 148End Page: 14
Deactivation of dietary wariness through experience of novel food
When a forager encounters an unfamiliar type of food, it must decide whether to eat it and risk being poisoned or avoid eating it and risk forfeiting a potentially valuable resource. Birds typically respond to such situations with "dietary wariness"; they show a transient aversion to approaching new food (neophobia), and many individuals also show a much longer lasting reluctance to consume the new food (dietary conservatism), even once neophobia has waned. Very little is known about how these processes, together termed "wariness," are controlled. We therefore present a series of experiments investigating how wariness of novel foods in domestic chicks, Gallus gallus domesticus, can be deactivated and reactivated by different experiences of colored foods, varying in their degree of novelty and palatability. We found that prior experience of a single novel color of palatable chick crumbs was sufficient to deactivate both neophobia and dietary conservatism of any other novel color of crumbs tested. Relatively little prior experience of a novel training food was needed to deactivate neophobia, after which the birds would peck at any other novel food. In contrast, much more extensive experience of eating a novel training food was needed before the birds would incorporate other novel foods into their diet. Chicks needed direct physical contact with the training food before they overcame their wariness to eat another novel food. However, observational learning was sufficient to encourage them to peck at the food (overcoming their neophobia). Reinstating wariness was much more easily achieved than its deactivation. We discuss these surprising results in relation to the foraging behavior of wild and domestic birds. Copyright 2007, Oxford University Press.
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