This is a ‘saguaro boot’. Let me explain what it is. Two species of woodpecker, Gilded Flicker (Colaptes chrysoides) and Gila Woodpecker (Melanerpes uropygialis) have adapted to live in arid desert environments in the SW USA and NW Mexico. Both species excavate nest holes in the fleshy trunks and limbs of saguaro cacti, but the plants treats these intrusive cavities as wounds and react by secreting a lignin sap that hardens around the hole chambers, effectively making protective sealing shell. Cleverly, the woodpeckers do not use the holes until the following year, waiting until the sap has dried out and the scar tissue of the chamber wall has become solid and watertight. When a cactus dies, its outer flesh rots away, but the tougher woody interior and the callus around any holes remain. These shells are angular in shape, keeping the form of the entrance and the chamber of the woodpecker cavity. These so-called ‘saguaro boots’ can be found on the ground amongst the debris of dead cacti. Interestingly, the boot in this photo is a double one! Thanks to Noel Snyder for sending me this remarkable image from Arizona, USA.
Friday, 29 September 2017
Wednesday, 27 September 2017
Saturday, 2 September 2017
Wednesday, 16 August 2017
Saturday, 3 June 2017
Saturday, 20 May 2017
WOODPECKER is due to be published this summer by Reaktion Books, London, in their acclaimed Animal Series. Written by Gerard Gorman the book examines not only the natural but the cultural history of the animal... how it has been viewed by people from ancient times to the present day, and examines the woodpecker in art, literature, media, religion, mythology, legend and folklore.
Tuesday, 7 March 2017
Wednesday, 22 February 2017
Friday, 17 February 2017
The Ground Woodpecker (Geocolaptes olivaceus) is a woodpecker which does not peck wood. It is arguably the most terrestrial woodpecker species on the planet, rarely seen near trees. Here is an image of its habitat and an earth bank with nesting holes (see very top right of the bank). This species is endemic to southern Africa (South Africa and Lesotho), where it is not uncommon locally. This location was in the Sani Pass in SA at around 2500m above sea-level (Gerard Gorman).
Friday, 20 January 2017
A REVIEW OF AN IMPORTANT NEW BIRD GUIDE WITH WOODPECKER CONTENT
BIRDS OF THE INDONESIAN ARCHIPELAGO: GREATER SUNDAS AND WALLACEA
by James A. Eaton, Bas van Balen, Nick W. Brickle & Frank E. Rheindt.
Published in November 2016 by Lynx Edicions, Barcelona, 2016. Hardback. 65 Euros.
This book is the first field guide to cover all the birds found in the Indonesian archipelago. This huge and ornithologically diverse area includes the islands of Sumatra, Borneo, Java and Bali (the Greater Sundas), and Sulawesi, the Moluccas and the Lesser Sundas (Wallacea) and the smaller islands amongst them. These two regions, divided by the Wallace’s Line, are shown inside the book in large and very helpful maps: the Greater Sundas inside the front cover and Wallacea inside the back.
A grand total of 1,417 bird species are covered in the book’s 496 pages. The comprehensive nature of the work means that, in addition to the region’s 601 endemics, the authors also detail 98 vagrants and eight non-native, introduced species. Every subspecies (race) is also described - a remarkable achievement by the authors. Many readers and reviewers, including myself, will occasionally question some of the taxonomic decisions made and thus the taxons included, but this is inevitable given the current state of avian taxonomy where no definitive list is agreed upon. It is enough to say here that the authors are very well-versed in today’s taxonomic issues and debates and made their decisions on what to include or omit, as species or subspecies, accordingly.
The text is backed-up by around 2,500 illustrations and 1,339 distribution maps. The concise texts on species are directly opposite the colour plates which also have the distribution maps included on them. All very convenient and ideal for use in the field. Although essentially a field guide, an introduction of sixteen pages, a bibliography of six and an index of sixteen, add to its weight and size, but this is inevitable for the book to be as comprehensive as it is and given the number of birds it deals with.
Having a keen interest in the Picidae, upon receiving the book I at once turned to the woodpeckers on pages 206 to 214. The first thing that struck me was that the illustrations were very familiar. Perhaps I was naïve, but I was eagerly expecting to see new colourful plates of my favourite birds, however, the artwork throughout the book is largely that of the Handbook of the Birds of the World, also published by Lynx Edicions. In retrospect, I fully understand the practical and economic reasons for reusing the artwork. Regarding the treatment of woodpeckers in this book (and indeed all other families), although the artwork is from HBW the text and taxonomy are not. The authors seemed to have been given license by Lynx to divert from HBW when they wished. For example, Chrysophlegma mentale is not split into two species here, as it is in HBW. One, perhaps trivial, thing I must mention is that the suggestion of the name ‘Lilliput Woodpecker’ for Hemicircus concretus (which HBW calls ‘Red-crested Woodpecker’) when split to species, was a little jarring.
Although the authors have obviously spent much time scouring papers, articles and reports, and examined museum specimens, it’s clear that the solid basis for this fine work is their field experience. Besides plumages and vocalisations, their acquaintance with behaviour, local distributions and habitats of the species shines through. Thus, this book is without question now the indispensable guide for those visiting this bird-rich region. I shall certainly be referring to it often. All in all, BIRDS OF THE INDONESIAN ARCHIPELAGO is a user-friendly, practical, well-researched and professionally produced work, and everyone involved should be congratulated.