Top 100 Birding Sites of the World

Information

SITE RANK

HABITAT Town and farmland area in tropical lowlands

KEY SPECIES Raptors, especially Turkey Vulture, Swainson’s Hawk, Broad-winged Hawk and Mississippi Kite, with 18 species recorded overall including Hook-billed Kite and Plumbeous Hawk

TIME OF YEAR A migration site, best mid-August to October, with impressive numbers also March to April

On a good day, raptors fill the skies above Veracruz.

The evocative name for this raptor migration viewpoint in eastern Mexico is no exaggeration. At times, when wide streams of birds fly over in continuous wheeling flocks, with no discernible beginning or end, almost from dawn until dusk, the effect really is of a vast aerial river of moving birds passing over, the circling birds being the river’s eddies. Such a wondrous spectacle is truly special and can be seen from several tropical watchpoints, especially in Central America, but the Veracruz river of raptors has the distinction of being much the most impressive in terms of numbers of birds seen. More than five million birds, mainly North American breeders, pass over the site during each post-breeding migration, which is easily the highest flight count anywhere in the world. Incredibly, more than a million raptors have been counted passing this area in a single day.

Veracruz is situated at a latitude where the North American continent narrows to form the funnel that is the Mesoamerican Land Corridor. Furthermore, it lies on the east side of the mouth of the funnel, on the Gulf of Mexico, specifically on a narrow strip of coastal plain sandwiched between the gulf to the east and a spur of the Sierra Madre Oriental just 7 km to the west. Since, in this hot climate, the birds have no need for mountain updrafts, migrating birds avoid the highlands and are greatly concentrated into this gap, or ‘bottleneck’, between mountain and sea.

Furthermore, this river of raptors flows at the point where several major flyways meet. Birds travelling down via the Appalachian Mountains meet birds following the Rocky Mountain Chain, and these mix with migrants that have used the corridors in between. Together, these huge flows of rap-tors converge on Veracruz to create what is equivalent to a huge junction in the sky, the world’s biggest bird motorway. South of this bottleneck, the paths of several species actually diverge, with Swainson’s Hawks and Turkey Vultures travelling the Pacific Slope, while Broad-winged Hawks take the Caribbean Slope. However, they all seem to pass through the Veracruz area.

Between September and November, the counts of raptors are simply enormous. Imagine, for example, seeing 707,798 Turkey Vultures in a single day, as happened on 17 October 2003, or 95,989 Mississippi Kites, as counted on 1 September 2002. Between 1999 and 2003, the mean counts for the major species were as follows: Turkey Vulture just over two million birds per season, Broad-winged Hawk 1,919,708, Swainson’s Hawk 901,827, Mississippi Kite 192,132, American Kestrel 7,322, Sharp-shinned Hawk 3,870, Osprey 3,256 and Cooper’s Hawk 2,716. Several of these species move through in rather short time-periods, so that on certain days thousands of birds of the same species can be seen. No wonder that this remarkable site, only recently discovered in its entirety, is beginning to draw rap-tor enthusiasts from all parts of the world.

There are several features of a semi-tropical site like this that differ from the more traditional hawk watch-points of the Northern Hemisphere, many of which are rather closer to the birds’ breeding grounds. Apart from the very high numbers recorded, raptors at Veracruz tend to move through less fitfully than at other sites. Movement is less weather-dependent, since thermals are more reliable, and birds will sometimes fly in conditions that would normally be considered unsuitable. Owing to the increased solar radiation, ‘streets’ of thermals form easily, allowing the birds to glide from one thermal to another as they move in a southerly direction. Thirdly, because of the angle of the sun, the ground warms quickly in the morning, allowing migration to begin much earlier than at more temperate sites. All in all, through-migration at this latitude is much faster than further north or south.

Variety adds spice to every hawk watch, and at Veracruz, as anywhere else, there is always the prospect of seeing something less common. Altogether, of the 18 species recorded on the watch here, 11 are irregular, including an eclectic selection of birds from north and south. These include Common Black Hawk, Harris’s Hawk, Snail Kite, Plumbeous Hawk and even Northern Goshawk. No doubt future years will see additional oddities turning up.

However, of greater interest are some true migrants that also arrive in smaller numbers, but regularly. These include several species that are largely sedentary in their breeding range, but which at these latitudes have turned into short-distance migrants. They include Hook-billed Kite (an average of 204 per season), Grey-lined Hawk (323) and Zone-tailed Hawk (140), all of them exciting for birders from further north.

At present the raptor counts are performed concurrently at two sites 11 km apart, one on a platform at the edge of a football field and one on the roof of a hotel, the latter with all facilities. It is perfectly possible for volunteers, or the simply curious, to witness these counts, and the organization involved, Pronatura Veracruz, has a strong education and media presence in the local community.

It’s hard to believe that, 20 years ago, this, the world’s largest movement of diurnal raptors, went largely unrecognized across these otherwise unremarkable skies.

Among the 18 species of raptors recorded here are relative scarcities such as Zone-tailed Hawk, a species which is recorded passing at a rate of 140 individuals per season.

An astonishing total of more than 700,000 Turkey Vultures has been counted passing Veracruz in a single day.