World Migratory Bird Day
The mysteries and complexities of bird migration have fascinated many human civilizations and cultures for centuries, if not millennia. World Migratory Bird Day is a global awareness-raising campaign highlighting the need to protect migratory birds and their habitats.
Despite modern methods that include bird ringing and satellite tracking, our understanding of the dynamics of how birds orientate and achieve sometimes truly global endeavours still remain unresolved, making it an exciting field of study for both academics and novices alike. A classic example of one of these anomalies is the dynamics of how the Barn Swallow shows an innate ability to navigate over continents during the non-breeding season to Southern Africa but find their way back to the same individual nest sites under British, French or German rooftops each year.
Globally 40% of all birds undertake a bi-annual journey, normally one southward and one northward, that varies in length between species and even between different populations within a single species. These marathons often present countless perilous dangers along the way and over a billion individuals die each year from predation, drowning or exhaustion.
Generally, birds migrate either to avoid unfavourable or even fatal conditions or to take advantage of particularly rich feeding or nesting grounds brought on by the annual fluctuations of the seasons.
From a South African perspective, a nation that receives many such visitors, making it one of the best birding destinations in the world, migrants tend to originate from three different sources:
- Intra-African migrants move within the continent often oscillating north and south over the equator and include birds such as Woodland-, African Pygmy- and Grey-hooded Kingfishers, Southern Carmine Bee-eater, 6 species of Cuckoo, Wahlberg’s Eagle and Red-breasted Swallow to name a few. Within Karongwe Game Reserve alone, up to 32 species of this type of migrant have been recorded from the months of November through to March.
- Altitudinal migrants refer to species that move from higher altitude breeding grounds to lower lying regions during the colder winter months and can include birds like Afromontane forest dwellers such as Narina Trogon, Black Saw-wing, Olive Woodpecker and Grey Cuckooshrike as well as montane and grassland breeders such as African Black and Alpine Swifts, Black-rumped Buttonquail, Short-tailed Pipit and Grey-rumped Swallow.
- The most recognizable type of migrants for most tourists visiting our shores are what is known as Palearctic migrants, most of which journey from European, Scandinavian or Middle Eastern nesting grounds and pass through land-bridges such as Gibraltar in Spain and Eilat in Israel These locations act as bottlenecks for thousands of passing birds, while others simply fly straight over the Mediterranean Sea in a single flight in order to take advantage of the subtropical bounty found here during the southern summer. Species such as Common and Great Spotted Cuckoos, European Roller, White Stork, European Bee-eater, Eurasian Golden Oriole, Lesser Spotted and Steppe Eagles, Montagu’s Harrier, Little Stint, Ruff, Red-backed and Lesser Grey Shrikes, Bar-tailed Godwit, Common Greenshank and Spotted Flycatcher are but a few examples of this type of visitor found in the region during the non-breeding season.
An important and much smaller subsection of this class of migrant are those that hail from Siberia and despite only being a handful of species do deserve a mention such as the yakutensis subspecies of Willow Warbler, Curlew Sandpiper and the globally threatened Amur Falcon.
The story of the Amur Falcon Falco amurensis is both a heartbreaking, yet equally impressive one. The entire world population, approximated at 500,000 pairs, migrates from steppe grassland breeding zones in northeastern Russia, northern Mongolia and parts of northern North Korea in late September across the Himalayas and over the Indian Ocean using an island-hopping approach from the Maldives to Seychelles, Mauritius, Comoros and Madagascar to finally end in the grassland and savannah biomes of Southern Africa, before returning in a similar fashion a few months later in a 22,000km round trip.
Some impressive investigative journalism in October 2012 brought to light that on one of the species most important staging grounds in the Indian provinces of Nagaland and Mizoram, traditional hunting involving the slaughter, sale and consumption of between 12,000 and 14,000 birds per day amalgamating to a staggering between 120,000 and 140,000 birds were being killed each year. However within 9 months of the exposure of this practice not only had the local and national government taken action and provided iron-clad legislation protecting the Amur Falcon throughout the country but even some of the very same people involved in the butchery had become the species greatest champions, particularly the youth of the region, advocating its conservation and future success.
Ultimately the human impact on migrating birds whether directly through practices such as bird liming on Mediterranean islands as a singular example or indirect such as the subtle impacts of climate change, many species of migrants are walking an ever-narrowing tightrope and general awareness of this, one of nature’s greatest spectacles, is needed more than ever.