The impact of heavy metal pollution on birds' behaviour and cognition: a comprehensive review

Description of the data and file structure Description: This dataset compiles raw data extracted from peer-reviewed studies included in a Biological Reviews synthesis examining the effects of heavy metal exposure on avian behaviour and cognition. Variables: Short_citationShort reference for the article, typically including first author and publication year. APA_citationFull bibliographic reference formatted according to APA guidelines. TitleTitle of the published article. Publication_yearYear in which the article was published. OrderTaxonomic order of the studied species. SpeciesScientific name of the studied species. LocationCountry of the research team that conducted the study and published the article. Metal_exposed_toHeavy metal(s) to which the studied individuals were exposed. Pop_housing_conditionHousing condition of individuals during the study:captive (born and studied in captivity),wild (studied in situ), orwild-caught (captured from the wild and then studied in captivity). Lifestage_indivs_when_first_exposedLife stage of individuals (egg, chick, adult) at first exposure to the focal heavy metal(s). Age_indivs_when_first_exposedAge of individuals at first exposure, when available, reported in days (d), weeks (w), months (m), or years (y). Exposure_durationDuration of heavy metal exposure, reported in days (d), weeks (w), months (m), or years (y). Exposure_frequencyFrequency at which heavy metal doses were administered (e.g. daily vs. one or multiple discrete exposure events). Lifestage_indiv_when_testedLife stage of individuals (egg, chick, immature, adult) at the time of behavioural or cognitive testing. Age_indivs_when_testedAge of individuals at first testing, reported in days (d), weeks (w), months (m), or years (y). Sex_individualSex of tested individuals:M = males, F = females, B = both sexes. Method_briefGeneral methodological approach used to assess effects of heavy metal exposure on behaviour or cognition:comparison between experimental groups,correlation between internal concentrations and behaviour, orcomparison between naturally exposed populations. Method_nb_groupsNumber of groups or populations compared (e.g. experimental groups, treatment levels, or populations). Method_detailsAdditional methodological information relevant to the study design. Total_sample_sizeTotal number of individuals included in the study. Exposure_dosageDose of heavy metal administered or encountered (experimentally or naturally). Units are reported as in the original publication, with no unit conversion. Multiple values indicate multiple exposure groups. NA indicates natural exposure without administered doses. Exposure_methodMethod used to administer the heavy metal (e.g. diet, osmotic minipump, injection). Pollutant_measuredHeavy metal(s) for which internal concentrations were measured. NA indicates no internal measurements. Concentration_measured_inBiological matrix in which heavy metal concentrations were measured (e.g.: blood, feathers, brain). Pollutant_measured_mean_concentrationMean measured concentration of the pollutant, reported in original units. Multiple values correspond to multiple groups or sampling times. Behaviour_endpointBehavioural or cognitive endpoint assessed. Variable_measuredSpecific variable quantified to assess the behavioural or cognitive endpoint. Main_resultBrief description of the main finding of the study. Effect_directionDirection of the observed effect: positive, negative, or none. Effect_significanceStatistical significance of the observed effect based on a 0.05 threshold:S = significant, NS = non-significant, AS = almost significant. CommentsAdditional remarks, clarifications, or notes relevant to the study or data extraction.