Birds of Tropical America: A Watcher's Introduction to Behavior, Breeding and Diversity (The Curious Naturalist) [Englisch] [Taschenbuch]

It is a shame that this book is out of print, because as more birders discover the wealth and happy confusion of birding in the tropics this book would find a ready audience. Birders who take their first trips to Central or South America step into an alien world, where the rules of the temperate zone do not apply.

Hilty's essays draw upon many years as a birding tour guide, kind of a "frequently asked questions" collection. He discusses answers to questions such as: Why do birds in the tropics migrate? Why are tropical birds often so colorful yet so hard to see? Why are tropical mixed flocks so large and varied (up to 50 or more species in a single foraging flock), and how can so many birds forage together? In the course of the essays, Hilty also provides a great deal of insight into tropical ecology. I would recommend this book to anyone with an interest in the tropics in general, and tropical birding in particular.

Steve Hilty does a wonderful job of translating the results of published scientific papers into the language of the curious layman without compromising the fidelity of the original research. With a strong academic background, coupled with many years of field experience and a formidable talent for communication, he successfully transmits the joy of the natural historian and the excitement of the pioneering ornithologist.

The book consists of twenty essays on the ecology, behavioural ecology, biogeography and evolution of Neotropical birds, each based on three or four seminal scientific papers. The topics covered include flocking behaviour, species diversity, intra-tropical migration, seasonality, song, hummingbird foraging ecology, seed dispersal and much more. Many of the topics arose as answers to the questions posed to the author by fellow travellers, so they address a host of the main questions the curious naturalist will ask. The examples and original research come from all parts of the New World tropics making this book of direct relevance to those travelling anywhere in Latin America. Specific sites mentioned range from La Selva in northeastern Costa Rica to Manu in Amazonian Peru, and from Panama's Barro Colorado Island to the Oilbird Cave in eastern Venezuela. Species like the Yellow-rumped Cacique and Oilbird and key Neotropical groups like the Vultures, Hummingbirds, Antbirds, Tyrant Flycatchers, Manakins and Cotingas are treated in detail.

In sum, a great introduction to the biology and natural history of American tropical birds for those who are new to the region and a fascinating companion for tropical veterans. Whether your interest is birding, natural history or simply enriching your tropical travels, this book should be on your shelves - or, better still, in your backpack.

One might guess by the title of Steven Hilty's book _Birds of Tropical America_ that he has written an informative though dry field guide, one that lists a number of birds of Central and South America but is not really a book to sit down and read. In fact, Hilty has written an engaging and extremely interesting natural history work covering many aspects of neotropical bird behavior, breeding, and evolution and is one of the finest popular science books I have read in a while.

The book is organized into twenty different chapters, several illustrated with black and white drawings by artist Mimi Hoppe Wolf, and includes an extensive bibliography. Roughly half of the chapters deal with aspects of neotropical avian behavior and physiology that are applicable to most if not all of the region's birds, while the remainder deals with specific types of birds, such as antbirds, hummingbirds, and vultures. The focus is largely on birds of rainforests but Hilty also discusses birds of mountains, grasslands, and in one interesting chapter, islands of the Amazon River.

The first few chapters tackle common questions asked about tropical American birds, questions Hilty has encountered over his years as not only a researcher but as a leader of birding tours in Central and South America. For instance, why are so many tropical rainforest birds so spottily distributed when there appears to be many hundreds of square miles of suitable habitat? Hitly wrote that distribution patchiness is a basic structural component of tropical rainforests; in an area that might contain up to 500 bird species, a particular acre or so of forest will only contain 100 to 200 species. One answer to this question is the existence of microhabitats, areas perhaps not obvious to naturalists recently arrived from temperate latitudes, but quite obvious to the local fauna. Some birds are found only along the edges of tree fall openings, while others that live in the canopy avoid areas where the canopy is discontinuous with tree fall openings. Birds might be rare because of their place on the food chain (harpy eagles occur generally at low densities though might be widespread throughout neotropical rainforests), of the lower population densities of tropical birds (the populations of the most common Peruvian rainforests birds are one-tenth that of those in temperate forests), the secretive nature of many understory rainforest birds (making them appear rare), and the large territories of birds (when compared to temperate species). A later chapter adds additional information; Hilty noted the work of Jurgen Haffer, who proposed that during the Pleistocene epoch the rainforests of South America at times contracted into isolated units he called refugia and that this repeated forest breakup increased speciation and helped produce many often small and localized ranges of birds in South America. Another theory, proposed by among others biologist Angelo Capparella, noted the importance of the major rivers of the Amazon Basin, which fragment the ranges of many widespread species and can act as barriers to gene flow; in a later chapter, Hilty noted how big a barrier the river can be, at one spot in Colombia, nearly 2,000 miles from the mouth of the Amazon River, the river banks are nearly five miles apart, a huge barrier to many tropical species that scarcely like crossing even forest trails.

Interestingly, many tropical birds migrate. No, not the famous temperate-to-tropics-and-back-again migrations, but migrations within the tropics, often quiet migrations that only involve some species and an aspect of the neotropics that took researchers many years to discover. These are short-distance migrations, perhaps a few miles or a few hundred miles. The quetzal and the bellbird for instance are fruit-eaters that breed in mountain cloud forests during the drier months of the year, but migrate downslope during the rainy season in search of drier conditions and more fruit. Even lowland forest species migrate to seek concentrations of fruiting trees, while others migrate to take advantage of the short-lived and unpredictable seed crops of bamboo, or in areas south of the Amazon Basin, are fire-followers, seeking out recently burned grasslands for breeding.

In a chapter on why there are so many more species in the tropics than in temperate areas Hilty noted the many niches unique to the tropics, for example antbirds, follow the swarms of raiding army ants, which flush small prey for them to eat, while other birds follow monkeys or the large peccary herds for the same reason (the latter of which are followed by the nimble, roadrunner-like ground-cuckoos).

Hilty discussed hummingbirds in two chapters, noting not only the many different hummingbird niches (some are nectar thieves, poking holes on the outside of flowers to get nectar, not aiding the plant in pollination one bit, others are territorial, while still others forage over large areas) but that they even have different niches at different altitudes (wing length and body weight have a huge influence in the type of flight and behavior a hummingbird is capable of and as higher altitudes have less dense air and produce less lift, some species have different ecological niches at different altitudes).

A number of chapters focused or dealt with breeding behavior. One interesting discussion analyzed why males might cluster together in lek assemblages when they are so extremely competitive. The "hotspot" theory of Jack Bradbury argued that leks form in areas where females forage widely for food and the males have a good opportunity to catch the attention of these wide-ranging females, while the "hotshot" theory of Bruce Beeler and Mercedes Foster argues that the success of a few dominant males attracts the attention of less successful males, who bide their time and try to move up the hierarchy.

Other interesting topics include the flycatchers (part of a group of birds called suboscines) which have been among the few animal groups to colonize northwards with the appearance of the Panamanian landbridge and the influence of environment on song (different terrains affect song propagation in different ways).