Three big birds - Imperial eagle

Photo Andi Li HKBWS (Dear Andy would you mind if I use this awesome picture in my blog? please get in contact. js)

“We’re not bunny huggers, we’re conservationists,” a seasoned bird spotter told me one day. He was describing what it was like to witness an imperial eagle launch itself at a flock of waterfowl, and scatter them in their thousands as it grabbed one carefully targeted individual, tearing it apart in a bloody mess of feathers and guts. 

    “An incredible sight,” he said with a sigh.

This came from a man who deeply values the avocets, herons, and ducks that yearly lure the raptors in to Hong Kong’s wetland marshes. He made me see that bird watching is much more than looking at individual birds, it’s an appreciation of the ecosystem that we share with them. 

    And the imperial eagle is an endangered predator at the apex of a vast system that connects subtropical Hong Kong to central Eurasia. Each winter a few individuals make it to Hong Kong, it could just be a pair one year, or perhaps five or six in another. It’s a raptor of similar dimensions to the white-bellied sea eagle, but a much darker bird with a more menacing reputation, reinforced by its martial name. If you’re lucky enough to witness it, its vicious attack on white feathered water birds is much more shocking than the sight of sea eagles carrying fish off in their talons. I had to cheat, by looking at stunning pictures captured by local birders. The closest I have come to spotting one was about 200m at Maipo nature reserve on a cold and drizzly February afternoon where an earnest twitcher pointed towards a distant clump of trees and told me there was one in there. Nice to know, but I couldn’t see it through my modest binoculars.

    

Photo borrowed  from HK magazine online

Worldwide the eastern imperial eagle is listed as vulnerable, with many local populations clearly declining. The usual suspects of habitat loss and prey depletion play a big part in endangering the species, but more direct threats from humans are often cited. Electrocution on power lines frequently kill individuals, and poisonings and shootings are regularly reported. The species is spread widely from Hungary in the west through Siberia and eastern China, and southwards down the east African rift valley to Kenya, and around the Arabian peninsula from Jordan to Yemen. Its total population is estimated in the thousands, so considering the massive range, we are again looking at a thinly dispersed species. But unlike the white-bellied sea eagle these birds are nomadic. They hitch a ride on the dramatic migrations of gentler birds, picking them off one-by-one as hunger drives them to the kill.

    Their presence in Hong Kong is thanks to what is possibly our most important natural asset, the Maipo marshes nature reserve. The protected wetlands serve a vital role, for Hong Kong, for China, for the East Asian-Australasian Flyway (EAAF), for the world. To understand that point you have to go back to the idea of the ecosystem, that every piece of wildlife you see is a part of an interlocking set of relationships with other life forms and habitats. 

     Every wild bird is a component, every migrating bird links the local ecology to a wider ecosystem. Mai po is a vital staging post and destination for some 60,000 birds every winter, and another 30,000 in summer. It is part of a 13,000 km chain of wetlands that joins arctic Siberia to untamed estuaries in Borneo, Papuan swamps and pristine shores of southern New Zealand lapped by icy Antarctic sea currents.

Credit: Wetlands International

    Every imperial eagle that arrives in winter connects Hong Kong to Mongolian grasslands and the Russian steppes. The wetlands that link the EAAF are few and far between, and they are being squeezed throughout Asia. Maipo is one of the best protected, and thanks to the WWF and the international Ramsar convention on wetlands, one of the best managed. It is a good place to feel hopeful about the state of the world’s water birds. The numbers are up and rarities keep returning. Around a fifth of the world population of blackfaced spoonbills continue to return every year. Another nine globally endangered migratory species continue to return annually, including imperial eagles.

    But impressions can be deceiving. The fact that life abounds in Maipo is at least partly due to the destruction of habitats elsewhere along the same flyway. Birds are being squeezed towards us because other options are running out. China’s breakneck development has concentrated on its densely populated eastern coast, thousands of hectares of marshes have disappeared in the spread of commercial territory. South Korea has killed off huge swathes of tidal mudflats in a decades old love affair with construction, as has Japan but with a head start uninterrupted by the Korean war. The more the neighbourhood is trashed, the more important Maipo becomes as a sanctuary. But surely one lesson of the flyway is that no wetland sanctuary exists in isolation. Maipo's ecology functions because other wetlands still survive, and it is shaped by the great migrations, including the epic hunt of the imperial eagle.

    The precise details of the great bird migrations are still little known, for the simple reason that it is very difficult to follow individual birds on their epic journeys. That’s why we don’t know where our imperials come from each year. We can make an educated guess that they could be Mongolian or Russian, but there would be no proof until we followed them. Though some clues can be gained tracking the prey that brings them to Hong Kong in the first place. 

     “The imperials are just eating other birds,” Bena Smith, WWF manager at Maipo told me. “Found one eating an egret yesterday, but they seem to like our duck too.” 

     Over two seasons the WWF management at Maipo took part in a United Nations Food and Agriculture Organisation satellite tracking study of migratory ducks. One of the reasons the UNFAO organised the study was to see what role, if any, wild birds took in the spread of the highly feared H5N1 bird flu virus. Bena Smith told me he was sceptical about the role of wildlife in spreading what he rightly called poultry flu, on the grounds that microbial studies identify the poultry industry as the source and incubator of the highly pathogenic forms of the virus. But he welcomed the study, partly because he just wanted to know where the ducks went, and partly because proof of their movements might clear the ducks' name as disease spreaders.

    Staff at Maipo attached tiny transmitters on 47 birds, and watched as the devices immediately started showing up on web-based tracking maps.

    One Northern Pintail took five months, starting in February, to fly from Hong Kong to the Arctic Circle, stopping along the way in China’s Yellow Sea region and the north eastern province of Heilongjiang. It stayed in Siberia for three months before heading southwards in September. From Eastern Russia it hopped over to Japan and then down to Southern China, returning to Maipo just in time for Christmas, after a 10,000 km round trip.

    Another tracking candidate, a Eurasian Wigeon, settled in North Korea for three months, on the border with the South, most likely inside the heavily mined Demilitarized Zone that separates the communist North from the capitalist South. This brings up an interesting point, the role of geo-politics in the preservation of wildlife. The Eurasian Wigeon is joined by the endangered blackfaced spoonbills in choosing the Korean DMZ as a resting, possible breeding, habitat. They are among some 3,000 wildlife species reported in the 4km wide, 250km long corridor of no-man’s land that separates the ideologically divided peninsula. Some environmentalists have even warned that the reunification of Korea would spell a disaster for the DMZ’s accidental biosphere. 

    Hong Kong’s Maipo has a surprisingly similar history, though not as nearly militarised. Its existence, and the existence an unspoiled wetland system that continues beyond the Ramsar protected site, is owed at least partly to what was called the Frontier Closed Area on Hong Kong’s northern boundary. The FCA was created by the British colonial regime in 1951 as a buffer against invasion from China, possibly by the military, but much more likely by ragged bands of illegal immigrants. Hundreds of thousands of people snuck over the border from mainland China, particularly during harsh political campaigns like the Great Leap Forward in the 1950s and the 10-year Cultural Revolution that began in the mid-1960s. The British overlords of the territory had an ambivalent attitude to the human tide. On the one hand they feared the colony would be swamped, and they could possibly lose control of the lucrative free trade port. On the other hand Hong Kong needed cheap labour to staff the manufacturing industries that fuelled the colony's growth.

    Chinese authorities on the other side of the border also had ambivalent attitudes. Emigration was effectively defection, and therefore deeply subversive. But on the other hand emigrants wired millions of dollars back home to their families, and remittances proved to be vital source of foreign currency for the then islolated regime. 

    So the British colonials came up with a hypocritical compromise that could only be invented by civil servants. In a policy that was informally known as "touch base", illegal immigrants would be turned away if they were caught in transit, but once they made it into the urban areas, and found accommodation, usually with relatives, they would be left to their own devices, which mostly meant taking up gainful employment in a factory.

    The FCA was a part of this compromise. It allowed the authorities to concentrate resources in one area, while ignoring the migrants who slipped past and melted into the workforce. Reports of illegal immigrants drowning in a bid to swim around the FCA, are made all the more tragic when you realise that they would have been given a chance to make a living if they'd reached the urban areas. 

    But the fact remains that the demarcation of the FCA was good for birds.  

    Villages that were inside the zone were frozen into a 1950s economy of shrimp farms and fish ponds. Their economic stasis was probably not particularly noticeable for the first couple of decades until developments started popping up in the New Territories. But the real explosion of growth came from the other side of the border, when former leader of China, Deng Xiaoping announced in 1979 that Communist China would have a go at capitalism in selected places, starting in the small fishing village of Shenzhen just on the other side of Maipo. From then on shrimp farmers in the FCA who had probably enjoyed relative wealth over their cousins across the river, could only watch in wonder as a mega-city grew from rice-paddies just a stone-throw away. Just 30 years later a city of 10 million bulges against the buffer zone.

    Every year for the past three-decades, imperial eagles have soared into Maipo within site of this growing mega-city. But even after Hong Kong’s 1997 return to mainland rule, the communist government maintained the territorial boundary, and kept the FCA closed. Thousands of birds packing the waterways of Maipo every year, continue to freely traverse the empty agricultural land well beyond the Ramsar protected site. Birdlife Inernational, the avian conservation group, recognises this de facto extension of Maipo’s formal boundary by listing an area about the same size as another Maipo, 1,500 hectares, as an Important Bird Area. Their justification for doing this is the simple fact that the same globally threatened birds, including eagles, imperial and greater spotted, that flock within the reserve boundary, regularly forage east along the beautifully undisturbed FCA. For now.

    The FCA remained in tact for the first decade of Hong Kong’s handover to China, but it is now being dismantled.  And many of the 9,000 or so remaining residents who watched Shenzhen explode into existence are expecting returns from what some people have called the “some of the the most valuable undeveloped real estate in the world.” Perhaps even more so, big developers are rubbing their hands with glee at such flat, strategic and unspoiled land. 

     One big chunk, called the Lok Ma Chau loop has already been earmarked a hi-tech education city that will house thousands of students and workers. It will cut right across the flight path of spoonbills, storks, and of course raptors in pursuit. The project is politically sensitive as it is hailed as major landmark in the economic and social integration between Shenzhen and Hong Kong, with investment pouring in from both sides of the border and much talk about partnership and joint development. 

    Maipo itself is promised protection as a nature reserve, but just as the health of the reserve is related to the health of wetlands in Korea, Taiwan and along the east coast of China, so it is it closely interwoven with its own back yard along the former FCA. Despite the large-scale development planned on the Lok Ma Chau loop, the Hong Kong government is at pains to explain its understanding of the special nature of the area, and of the value of conserving its unique environment. It has drawn up plans with the help of global construction giant ARUP, to show lovely cycle paths, and eco-lodges for tourists to enjoy unobstructed views of wild birds -- and Shenzhen. My fear is that in the rush for profits genuine ecological initiatives could easily be by-passed for superficial gimmicks -- like a pets corners for bunny huggers.

   The real conservation performance will be measured by biodiversity, including the number of endangered species that return to the area. And with the imperial eagle down to a single pair in some years, they will be a good indicator of Hong Kong’s performance on conservation.