Birders, your country needs you
2009-08-27 12:26
Cape Town - Are you an avid birder and would love to do something for the environment? Well, now is your chance - your country and feathered friends need you.
Researchers at the South African Environmental Observation Network (Saeon) are calling on local birders to join them in monitoring the impact of climate change on bird migration behaviour in the lowveld and bushveld regions of South Africa.
"Volunteers will be asked to record the arrival date of some of the more common, easily identifiable migratory birds in their gardens, farms, workplace or in their favourite birding area on a monthly basis," says project manager Nikki Stevens.
Though Stevens is especially looking for dedicated birders who would be willing to record the arrival date of migrant birds over a number of years, anyone can join the programme.
"Birding experience is not essential," Stevens told News24. "The Bird's Eye View migration monitoring project welcomes anyone who is interested in participating.
"We've specifically chosen some of the most recognisable migrant birds as our target species so that even people with little or no birding experience will be able to confidently identify them.
More experienced birders are encouraged to also send in sighting reports of the less common migrant species.
A Barn Swallow. (Saeon)
Citizen scientists have been assisting Saeon's Ndlovu Node in their bird monitoring project since 2007.
"The inclusion of the public in our 'citizen science' projects is invaluable in expanding the monitoring network," says Stevens. "So everyone who is willing and able should register as an observer."
Ndlovu, an observation platform responsible for long-term environmental monitoring in South Africa's savanna biome, plans to keep the programme running indefinitely as it is yielding valuable and much-needed information to detect reductions or expansions of the ranges of certain savanna bird species.
So, which are the most common migratory birds that visit the lowveld and bushveld regions of SA every year?
The most common and among the most noticeable migrants to these parts are some of the swallows, the Southern Carmine and European Bee-eaters, the European Roller, the Woodland Kingfisher, several cuckoo species and raptors; namely the Yellow-billed Kite and the Wahlberg's Eagle, says Stevens.
A Carmine Bee Eater. (Jeanette Bowers-Winters)
"The European and Carmine Bee-eaters are perhaps the most colourful of the migrants. They are brightly coloured aerial feeders with long decurved bills and long tails.
According to Stevens, they often occur in flocks and are most commonly seen perched on dead branches from where they hawk insects.
Another common sign signifying the arrival of summer is that of the Yellow-billed Kites.
"These are large, brown raptors with long wings and a yellow bill and are easily identified by their V-shaped tails.
"These birds are often noticed flying at low heights scanning for food and they are not above scavenging for road-kill or around human settlements.
"Some of the most commonly heard (but not so easily seen) summer migrants are the cuckoos, with the Red-chested Cuckoo welcoming summer with its distinctive 'piet-my-vrou' call."
Another hard-to-miss lowveld bird is the beautiful cobalt blue Woodland Kingfisher.
"Males of this species call near-continuously from when they arrive until they depart again in autumn. The loud 'chip', followed by a descending 'trrrrrrrrrrrrrrrrrrr', is unmistakable."
A European Roller. (Jeanette Bowers-Winters)
Mounting evidence of climate change
With almost one degree of warming having occurred over the past century, scientific work shows mounting evidence that birds are being negatively affected by the change.
Long-term environmental monitoring has indicated that global climate change has already extended plant growing seasons, changed animal and plant distribution patterns, and altered the annual dates of flowering, breeding, and bird migration.
As far as bird migration is concerned, the emerging picture shows that many species that breed in the northern hemisphere have been arriving later than normal in South Africa since the second half of the 20th century.
The delayed arrival can result in birds missing important food peaks, which can have disastrous impacts on bird populations.
"Birds are excellent indicators of climate change as they are very sensitive to climate and weather," Stevens explains.
"They are also very important indicators because large amounts of information on their behaviour and migration patterns have been collected by members of the public, specifically in the northern hemisphere."
In Britain, for example, the arrival dates of certain migratory birds have been recorded by members of the Royal Meteorological Society since 1883.
This very important long-term series of observations has generated a wealth of valuable long-term data in the northern hemisphere.
Are there any examples of bird species arriving later in South Africa because of climate change? And how does it affect their population?
"There are no clear examples from South Africa yet, as we just don't have the depth of long-term information that is available for migrant species from several northern hemisphere countries," says Stevens.
"However, global climate change is likely to affect birds here as well, if not already," she continues. "We just don't know yet exactly how they are affected."
It was to help bridge this gap in knowledge that Saeon joined the ranks of organisations involved in gathering information on bird migration two years ago.
According to Stevens, the well-researched Pied Flycatcher from northern Europe is a good example of climate change's impact on migrant birds.
"Typically these flycatchers arrive in Northern Europe in spring, just before their most important food source, a caterpillar begins to emerge en masse.
"Climate change has brought about warmer European springs, causing trees to come into leaf earlier and insect populations to peak before the arrival of the birds.
Delayed migration
"Research has shown that the females are trying to compensate by breeding earlier, but this is often prevented by the physical stresses of migrating," Stevens explains.
Subsequently this species has seen a large decline in numbers in recent years.
Other problems can occur if birds delay their departure date (if they arrived later or if the current weather is particularly warm) as they then must face harsher climatic conditions during their migration (e.g.flying into winter storms).
Delayed migration increases the chances that birds will be exposed to winter cold snaps before they leave.
An example of this was documented in Limpopo, South Africa, two years ago, when several hundred swallows died because of unseasonably icy conditions, Stevens concludes.
Get involved
If you are based in a savanna region and are interested in participating in the project - or have already been collecting such information - send an email to birds@saeon.ac.za, or download a registration form here.