Handbook of Avian Hybrids of the World [Hardcover]

How many hybrid birds do you think there are? It's a tougher question than you might imagine. A quick check of my notebooks shows that in the last year I have seen a couple of dodgy-looking Ferruginous-type Ducks, some weird Canada x Barnacle Geese and number of bizarre-looking pheasants. Not many then - but I think you will be surprised to know that about 4000 hybrid forms have been recorded from around the world. This book lists them all, using 5000 references to ensure comprehensive coverage.

A total of 4000 types of pairing seems huge when you think that there are only about 10,000 species out there, but actually it is quite small when you realise that the number of possible alternative pairings for each species is very large. This book lists both natural hybrids from the wild and those that have occurred in captivity, and the author has been careful to delete any inaccuracies discovered in previously published literature.

One of the most and famous hybrids in the USA is known as "Brewster's Warbler", which adorns the cover of this scholarly book. This bird was first noted back in the 1870s, but for years American ornithologists argued over its true origins. It is now known that this bird is in fact a regularly-occurring hybrid between Golden-winged Warbler and Blue-winged Warbler. Indeed the matter gets worse, because "Brewster's" Warblers have been known to go onto breed successfully with other warblers that then create offspring that are known as "Lawrence's Warbler". This handbook is packed with information such as this

Another well-known hybrid is "Cox's Sandpiper" which was first noted in Australia in the early 1990s. Although it was thought to be a new species at the time we now know that this form is in fact a hybrid between Pectoral Sandpiper and Curlew Sandpiper. But how many other hybrid wader types have been recorded? Well, checking through the species accounts I can quickly see that Curlew Sandpiper has also bred with Dunlin and White-rumped Sandpiper, and that Knot has bred with Bar-tailed Godwit, to mention just a few examples.

In the UK we really should be alert to the various hybrids that exist. Take for example Herring and Lesser Black-backed Gulls which are variously pairing with Yellow-legged Gulls and occasionally Glaucous Gulls. Similarly there have been numerous cases of hybrid terns, and of course for several years a Lesser Crested Tern paired with a Sandwich Tern in the Farne Islands. There is also the recent breeding of a Red Kite and Black Kite on the Black Isle.

Some people will take the view that successful hybridization is simply an example of evolution taking place, but it is worrying when a declining species can become threatened by its successful hybrids. Some people in the USA are worried that in time the declining Golden-winged Warbler might be pushed aside by the hybrids that it has helped to create. Similarly the big debate about culling Ruddy Ducks was based on the risk that they would mate with White-headed Ducks in southern Europe. The latter was, of course, far from natural evolution.

This tome is really impressive in its depth and scope, however I was left feeling really disappointed that none of these species is illustrated inside. A quick search using Google reveals that there are photos of many hybrid pairings from all over the world and I would have found it useful to have some of these shown within this book.

This is an excellent book, but make sure you see a copy before you decide to buy it. I see it is a reference work that you will want to occasionally consult, but for most people it would have limited value. It is, however, invaluable as a reference for researchers, and clearly was a labour of love for Eugene McCarthy.

This is very useful of my ornithological life! Author is createve new-way of systematic accounts. My country ornithologists have not such works.

I am impressed by the collection ov bird hybrids and how fertile they are.
I have worked whith gene flow between related species and have great help by this book!

Tomas Tymark, Sweden