Mean (± SE) counts of nutcracker pecks (exploration, EXP) during experiment 2.

<p>Filled circles: experimental birds; open circles: non-enriched controls. See text for explanation of time periods.</p

Observation schedule for nutcracker behaviors during Experiment 2.

<p>Observation schedule for nutcracker behaviors recorded during Experiment 2. LTF = latency to feed, AL = activity level, EXP = exploration. See text for definitions of behaviors.</p>1<p>All behaviors were measured for 5 mins.</p

Mean (± SE) nutcracker feather CORT values (pg/mm) from experiment 2.

<p>Filled circles: experimental birds; open circles: non-enriched controls. (A) shows the first four time periods of the experiment; (B) shows the fifth time period (non-novel enrichment) and includes short-term (novel) enrichment for comparison. Note different scales on y-axes. See text for explanation of time periods.</p

Mean (± SE) latency (sec) to feed (LTF) of nutcrackers during experiment 2.

<p>Filled circles: experimental birds; open circles: non-enriched controls. See text for explanation of time periods.</p

Experimental timelines with diagrams illustrating how feather sections reflect periods of the experiments.

<p>Feathers from experiment 1 were cut into three sections corresponding to periods prior to pre-enrichment (A), short-term enrichment (B), and removal of enrichment (C). The first feather from experiment 2 was cut into two sections corresponding to pre-enrichment (A) and short-term enrichment (B), and the second feather from experiment 2 was cut into three sections corresponding to long-term enrichment (C), removal of enrichment (D), and non-novel enrichment (E). See text for descriptions of time periods. Note: illustrations not to scale.</p

Common eider data for Harms et al MS: Feather corticosterone reveals effect of moulting conditions in an Arctic migratory bird

These data were collected from the field from 2007-2011. Column headings are as follows: ID (year plus bird band number); Band (bird band number); year (year eider was captured); CORTf (feather corticosterone in pg/mm); arrival (eider arrival date on breeding colony in Julian days); relArrival (relative arrival date); mass (eider mass in grams); Lay (date first egg was laid); relLay (relative lay date); nest (at least one egg was successfully hatched); Survival (1=eider found dead by end of breeding season, 0= eider that was not found dead during breeding season

Comparing CORT levels in juvenile birds from young and mature forest during the sensory phase.

<p>CORT levels (mean ±SEM) in natal feathers are higher in birds that settled in mature forests compared to birds settling in young forests (General linear model, F_1,37 = 4.71, N = 46).</p

Correlation between CORT levels during sensory phase and syrinx weight.

<p>Syrinx weight of black-capped chickadee in their first spring is correlated with CORT levels of their natal feathers (regression analysis, R² = 0.1, N = 20, p = 0.03).Circles represent birds from young forest; squares represent birds from mature forest.</p

Comparing the development of syrinx, RA and HVC across habitat.

<p>(a) Birds from young forests have a lighter syrinx than birds in mature forest (F_1,17 = 5.86, N = 20, p = 0.02). (b) An intermediate effect (based on power analysis) was found between RA volume in young vs. mature forests; birds in young forests tend to have a bigger RA volume than birds in mature forest (F_1,17 = 0.81, N = 20, p = 0.38; d = 0.38). (c) HVC volume did not differ significantly across habitats (F_1,17<0.01, N = 20, p = 0.99; d = 0.13). Values presented are Means ±SE.</p

The association of raptors and corvids with Paleolithic humans across the Palearctic.

<p>The table is divided into three sections, the first covering scavenging birds, the second non-scavenging cliff-nesting birds and the third covering the remaining species. Scavengers are separated into type 1 (obligate) and type 2 (facultative, ranging from frequent to occasional). Scavengers that are also cliff nesters are assigned an * if they are solitary nesters and ** if they are colonial. Each species is allocated to a size class according to the following scale: 1 - all individuals <100 g; 2 - some individuals <100 g and others between 100 and 1 kg; 3 – all individuals between 100 and 1 kg; 4 – some individuals between 100 g-1 kg and others between 1–10 kg; 5 all individuals between 1 and 10 kg; and 6 some individuals between 1–10 kg and others >10 kg. Species which are overrepresented in Palaeolithic sites (Middle and Upper) compared to paleontological sites, tested by chi-square (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045927#pone.0045927.s008" target="_blank">Text S1</a>), are indicated by a “yes”. Species that are overrepresented in Middle over Upper Palaeolithic sites are similarly indicated. Degree of significance: *** p<0.001; **p<0.01; *p<0.05. Cases of possible overrepresentation in Palaeolithic sites but with sample sizes that are too small to provide definitive evidence are indicated as “possible”. Remige feather colour: d = dark; i = intermediate - this includes birds with light brown or more often spotting or barred patterns so have some white and some dark per feather; and m = mix where some feathers are white (e.g. primaries) and some are black (e.g. secondaries). Over-repr. = over-represented; PS = Palaeolithic sites; MPS = Middle Palaeolithic sites. Statistical analyses are provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045927#pone.0045927.s006" target="_blank">Tables S6</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045927#pone.0045927.s008" target="_blank">Text S1</a>.</p