Frequency distribution of ground speed between consecutive GPS locations of incubating Peruvian pelicans.

<p>The inset graph shows the cut-off value to discriminate flying speeds from floating on the water speeds. The outer distribution depicts the mean flight speed.</p

Foraging variables of incubating Peruvian pelicans (<i>Pelecanus thagus</i>) from isla Lobos de Tierra, Perú, instrumented with GPS dataloggers.

<p>*Truncated approximately 5 km from the island during the inbound path.</p

Sinuosity index during the beginning (outbound path), middle (food search) and ending (inbound path) stages of the trip.

<p>Box plots depict the 10, 25, 50, 75 and 90 percentiles of the distribution. A sinuosity index close to one means high path linearity.</p

Acceleration data

Depth, body and head acceleration data from 8 Magellanic penguins and 10 Imperial cormorant

Morphometry and flight characteristics of the two vultures in different weather conditions. Values are mean ± SD with sample size in brackets.

<p>Morphometry and flight characteristics of the two vultures in different weather conditions. Values are mean ± SD with sample size in brackets.</p

Relationship between VeDBA, behaviour, ODBA and power from Long necks enhance and constrain foraging capacity in aquatic vertebrates

Highly specialized diving birds display substantial dichotomy in neck length with, for example, cormorants and anhingas having extreme necks, while penguins and auks have minimized necks. We attached acceleration loggers to Imperial cormorants <i>Phalacrocorax atriceps</i> and Magellanic penguins <i>Spheniscus magellanicus</i>, both foraging in waters over the Patagonian Shelf, to examine the difference in movement between their respective heads and bodies in an attempt to explain this dichotomy. The penguins had head and body attitudes and movements that broadly concurred throughout all phases of their dives. By contrast, although the cormorants followed this pattern during the descent and ascent phases of dives, during the bottom (foraging) phase of the dive, the head angle differed widely from that of the body and its dynamism (measured using vectorial dynamic acceleration) was over four times greater. A simple model indicated that having the head on an extended neck would allow these cormorants to half the energy expenditure that they would expend if their body moved in the way their heads did. This apparently energy-saving solution is likely to lead to greater heat loss though and would seem tenable in slow-swimming species because the loss of streamlining that it engenders would make it detrimental for fast-swimming taxa such as penguins

Example of flight track, heart rate and behaviour.

<p>A) One of the flight paths followed by the Himalayan griffon vulture under sunny conditions, with information on HR (gradient of colour from red (HR>300 bpm), orange, purple, to blue (HR<100 bpm)) and behaviour (small dots  =  soaring/gliding; large dots  =  flapping) superimposed. The black star marks the start and end of flight and black arrows give the first direction of flight. Soaring phases are numbered in black for an easy correspondence with panel B (see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0084887#pone.0084887.s001" target="_blank">Fig. S1</a> for 3-D visualization); B) a time-based projection of altitude (top), heart rate (HR, middle, in red) and an index of body activity based on acceleration signals, highlighting the flapping and walking bouts (ODBA, bottom, in black). For the altitude panel, the colour of the line changes with behaviour (with the flapping bout marked by a red arrow) and the green numbers refer to the same soaring phases as in panel A.</p

Correlation between heart rate and ODBA.

<p>Correlation between mean ± SD heart rate and Overall Dynamic Body Acceleration (ODBA) for the Himalayan (Himalayan griffon, red) and Eurasian griffon vultures (Eurasian griffon, blue): a) values averaged over one minute (including data from flight and from land (from TO-10 to LD+10); n = 382 min for Himalayan griffon and 337 min for Eurasian griffon). Regression lines are drawn in red for Himalayan griffon (R² = 0.729) and in blue for Eurasian griffon (R² = 0.688). b) values averaged over complete flights (TO to TO+17; no data from land), separating sunny (circles, 13 flights: 6 for Himalayan griffon and 7 for Eurasian griffon) and cloudy days (triangles; 7 flights: 4 for Himalayan griffon and 3 for Eurasian griffon).</p

Variation of mean heart rate with weather conditions.

<p>Mean heart rate (± SD) calculated every minute, before flight (TO-10 to TO-1), at take off (TO), during flight (TO+1 to TO+17), upon landing (LD-2 to LD+1) and after landing (LD+2 to LD+10) for two griffon vultures, in sunny (red) and cloudy days (blue). The horizontal line represents baseline HR (when perched).</p

Dendrographic analysis of PFGE (<i>Xba</i>I-digested DNA) of <i>Salmonella spp.</i> from land iguanas (<i>C. subcristatus</i>) sampled in December 2003 from the island of Santa Cruz, Galápagos, Ecuador.

<p>*: Somatic phase damaged.</p