Diving behaviour of two Australian bimodally respiring turtles, Rheodytes leukops and Emydura macquarii, in a natural setting

Time-depth recorders were used to investigate the diving performance and behaviour of two bimodally respiring turtle species, Rheodytes leukops and Emydura niacquarii, known to have a high and low reliance on aquatic respiration, respectively. Significant differences in diving performance between R. leukops and E. macquarii were observed in the number of dives/day (39.3 +/- 5.38 vs 112.2 +/- 11.73 dives/day; mean +/- SE), mean dive length (33.1 +/- 7.33 min vs 9.6 +/- 2.26 min) and maximum dive length (623 +/- 104.74 min vs 67.1 +/- 8.14 min), respectively. Differences in diving performance between R. leukops and E macquarii are attributed to the species' reliance (or lack thereof) upon aquatic respiration. Rheodytes leukops displayed a weak bimodal pattern of increased surfacing frequency in the early morning (05:00-07:00) and late afternoon (14:00-18:00), while E. macquarii displayed a strong bimodal pattern of elevated surfacing frequency over similar time periods. Daily patterns of increased surfacing frequency for both species failed to correlate with fluctuating aquatic Po-2 levels or water temperature, and may instead be explained by the heightened activity levels of both species during twilight.

Glazing to entry, Mt. Nebo House

Leadlight windows with stained glass feature panes and timber muntins over french doors with matching leadlight sidelights.

Dining room, Mt. Nebo House

Interior view showing fireplace and mezzanine.

Hallway, Mt. Nebo House

Hallway off main entry to house.

Dormer window, Mt. Nebo House

Arched head leadlight and casement windows with stained glass feature panes and timber muntins. View through window from interior.

Dormer window, Mt. Nebo House

Arched head leadlight window with stained glass feature panes and timber muntins.

Garage-studio interior, Mt. Nebo House

Timber framing and roof skylight detail inside garage-studio.

Upper level, C House, Coorparoo, Brisbane

View along North-West elevation upper level.

Iwan, C House, Coorparoo, Brisbane

As seen from pool deck.

The Nest, C House, Coorparoo, Brisbane

Timber deck with built-in seat overlooking greater landscape beyond.

Pool deck, C House, Coorparoo, Brisbane

View back towards house from deck. with Iwan (right) and filter room (left).

The Nest, C House, Coorparoo, Brisbane

Concrete framework for The Nest (North-West elevation), with timber framework yet to be added.

North-West elevation, C House, Cooparoo, Brisbane

Entry stair in foreground.

Pool deck, C House, Coorparoo, Brisbane

As seen from The Nest above