---
title: "Tropical Wedge-tailed Shearwaters do not dive as deep as higher-latitude shearwaters"
---

# Tropical Wedge-tailed Shearwaters do not dive as deep as higher-latitude shearwaters

David Hyrenbach ([Oceanic Institute, Hawai’i Pacific University](http://www.oceanicinstitute.org/education/hpu.html), Waimanalo, Hawaii, USA) and colleagues report in *[‘Elepaio](http://www.hawaiiaudubon.org/#!elepaio-newsletter/cxrn)* (Journal of the Hawai‘i Audubon Society) on depths achieved by four diving Wedge-tailed Shearwaters *Puffinus pacificus* (WTSH) in Hawaii carrying tail/mounted time-depth-recorders (TDRs).  Maximum dive depth attained was 21.8 m.  Both single and multiple (bout) dives were recorded.

 “[T]he mean maximum dive depths we recorded for WTSH are shallower than those of related sub-arctic, subtropical and tropical species [of shearwaters].  This result is consistent with anatomical evidence suggesting that WTSH are not deep divers, due to having significantly less laterally compressed tarsi than other diving species, like the Short-tailed Shearwater and the Sooty Shearwater.”

 The paper concludes: “[f]uture research could further investigate the ecological context of night-time foraging and dive bouts.  To this end, we hypothesize that single dives and dive bouts indicate solitary foraging events and multi-species feeding flocks involving subsurface predators, respectively."

 ![](https://acap.aq/images/stories/acap/Birds/Shearwaters/Wedge_tailed/wedge-tailed shearwater_alan_burger.jpg)

 Wedge-tailed Shearwater, photograph by Alan Burger

 **Reference:**

 Hyrenbach, K.D., Gleichman, J.S. & Karnovsky, N.J. 2014.  Diving behavior of Wedge-tailed Shearwaters rearing chicks on Lehua Islet.  [*‘Elepaio* 74(4): 1-4](http://www.pelagicos.net/Reprints/2014/Hyrenbach_et_al._Elepaio_2014.pdf).

 *John Cooper, ACAP Information Officer, 24 March 2014*