Migratory bird species in the UK

I will always maintain that the loveliest spring and summer are experienced in England. Apart from the profusion of flowers and exceptionally pleasant weather, there was always a persistent backdrop of birdsong, regardless of whether I was in town or country, sidewalks or fens. This chorus now stands the danger of disappearing from the British Isles, as explained in the 2010 Breeding Bird Survey (BBS) report which lists the statistics of bird population from 1995 to 2010. But first the good news…

Good news:

- Two warbler species have reached their highest numbers in 15 years: Blackcap (+73%) and Whitethroat (+25%). The Whitethroat population had plummeted in 1969 due to the drought in Sahel (the arid zone south of Sahara where they spend winter), but have now risen probably due to increased rainfall in the region.

-Chiffchaff (+52%).

Bad news:
10 species have experienced a decline in population numbers between 1995 and 2010. Of these, 8 are annual migratory species which spend autumn and winter in sub-Saharan Africa and return to the UK in spring and summer for breeding (viz, turtle dove, cuckoo, nightingale, wood warbler, whinchat, yellow wagtail, pied flycatcher, and spotted flycatcher).

-Turtle dove: a decline of 74%, with 2009-2010 experiencing a slump of -21%.
-Nightingales: decline of -63%, with a -27% fall in the 2010 level from the 2009 levels. Now seen mainly in SE England.
-Wood warblers: -60%
-Whinchats: -55%
- Yellow wagtails: -55%
- Pied flycatcher: -51%
- Cuckoo: decline of -48%; Now more commonly sighted in Scotland than in England.
- Spotted flycatcher: -47%
The two non-migratory species which have shown a marked decline are:
- willow tit (-76%)
-grey partridge (-54%)

The trend is that relatively short-distance migrants (such as Blackcap and Chiffchaff which fly down to southern Spain and Northern Africa, without crossing Sahara) are doing better, whilst those that travel further (such as Turtle Dove, Cuckoo, and Nightingale) are showing a steady decline in population. The reasons are postulated to be habitat destruction (due to anthropogenic factors), desertification, hunting, and repercussions of climate change- but it is most likely to be a combination of many factors. Since the bird species’ migration corridor covers many regions/countries during the course of the year, the manifestation of any such factor anywhere could act as a leverage point.

* I apologise for any mistakes which might occur when one had taken a cocktail of medicines (am battling a wrist sprain, (another) bout of food poisoning, and an exceptionally torturous flu- all at the same time).

Image source: Scott Barrow/Corbis

Stuck in traffic

As you sit in the rush hour queues, pity the poor guy or girl directing the traffic, and imagine the fumes they are breathing in. In Brazil, with rapidly expanding car ownership, but not necessarily expanding road space, this is an increasing problem.

A recent study* in the city of Santo Andre, part of the metropolitan region of Sao Paulo, focused on traffic controllers. The study focused on male, non smoking, traffic controllers who had been exposed for over 3 years. As the authors note, one criticism of the study is that it might actually underestimate health concerns, as unhealthy controllers were excluded from the test group to achieve homogeneity. Thus the subjects might be constitutively more able to adapt to air pollution, or just have healthier working practices.

The study concentrated on particles in the air (from dust, car exhaust etc) and ozone. The level of particulate matter has fallen in recent years, below the official limits of 50 and 25 ug/m3 for PM10 and PM2.5 respectively (PM 10 and 2.5 are different particle sizes), but that is still considered hazardous by many observers. Road dust accounts for about 30% of air pollution and is mainly composed of PM 10 particles, so the authors concentrated on this size in particular. Furthermore ozone levels are increasing, especially at times of high temperatures and low humidity. High ozone has been associated with cardiovascular disease.

They found that both PM10 particulates and ozone were associated with increased blood pressure, but in different ways. PM10 pollution caused a blood pressure rise almost immediately, which still remained 4 hours later, whilst the effect of ozone delayed for 2 hours of exposure, but was still apparent 5 hours later.

So, the traffic controllers are suffering measurable cardiovascular effects every day, continuing even when the pollution is removed, and in quite a stressful job. It might not end there. The so called "interior diesel" used in some cities such as Santo Andre has a lot more sulphur than the diesel distributed in the main cities (1,200 vs 500 ppm), which has been shown to cause endothelial disfunction, oxidative stress, and probably long term hypertension.

It's a dangerous job, standing in the middle of traffic, in more ways than one.

Sérgio Chiarelli P, Amador Pereira LA, Nascimento Saldiva PH, Ferreira Filho C, Bueno Garcia ML, Ferreira Braga AL, & Conceição Martins L (2011). The association between air pollution and blood pressure in traffic controllers in Santo André, São Paulo, Brazil. Environmental research, 111 (5), 650-5 PMID: 21570068

*P.S. Chiarellietal et al 2011. The association between air pollution and blood pressure in traffic controllers in SantoAndre, Sao Paulo, Brazil Environmental Research 111 650–655

Development vs Environment

Actioni contrariam semper et æqualem esse reactionem: sive corporum duorum actiones in se mutuo semper esse æquales et in partes contrarias dirigi.

So spells out Newton’s 3rd law of motion, also equally valid in a tug of war between the government and the residents bordering the Veli Lake in Trivandrum district.

It all centers around the construction of a 220-metre long and 100-metre wide ‘breakwater’ at the mouth of the Veli estuary, designed as a flood control scheme under the Rs 12 crore ‘Kerala Sustainable Urban Development Project’. The general aim is to prevent the seasonal formation of a sandbar at the estuary, thus ensuring a continuous flow of water (from Veli Lake, the interconnected Aakulam Lake, feeder canals viz. Parvathy Puthanar, Amayizhanjan, and Chakka, and rivers viz. Karamana and Killi) into the Arabian Sea. The enumerated benefits are:
-control of flooding in the city, especially during the rainy season,
-addressing the rampant problem of aquatic weeds in the Veli and Aakulam lakes,
-removal of water stagnation in the lake, thus improving water quality,
-enabling fishing even during storms (!!!)
-boosting the development of the Veli tourist village.

Local groups are reluctant to view these as ‘benefits’. The Veli and Aakulam lakes (and their feeder canals and rivers) are already plagued by severe water pollution, thanks to garbage dumping and waste water (both domestic and commercial- including hospitals and factories). Furthermore, factories empty their chemical effluents (usually, untreated) either into the lake (and its feeder canals), the estuary, or into the nearby sea. They are concerned that:
-the breakwater would pollute the sea more since many would take advantage of an easy disposal of effluents and waste water,
-this would affect the fish population and, consequently, jeopardise the livelihood of local fishermen,
-scum and solid waste would be deposited on the beaches, affecting the tourism.

Usually, when there is a will (i.e. the government’s), there’s a way. It remains to be seen how this issue will be resolved. The pale yellow patch are the effluents from the factories, thoughtfully dumped into the sea.

Sources: local newspapers

The fine line

Animal-human skirmishes are recurrent occurrences, typically at forest-settlement boundaries. Such examples abound in the forested, mountainous Western Ghats, where the humans have (legally and illegally) established their dwellings and agricultural fields virtually on the doorsteps of the forest inhabitants. Such conflict can be mainly classified into two:

-When humans encroach (mostly unlawfully) into their territories to collect firewood or forest products (including illegal felling of trees and hunting of deer and rabbits).

-When wild animals stray into the settlements and agricultural lands, usually during times of drought when the streams dry up. In the case of Ponmudi, the Kallar river becomes the focus of such skirmishes: the areas bordering the perennial (but relatively shallow) river continue to be fringed with foliage and both parties wage their battle over the resources. This is further aggravated by humans who illegally harvest wild grasses and reeds (Ochlandra travancorica) during the fair weather. This deficiency and destruction of habitat shifts the animal population towards the fertile agricultural lands with consequences such as attacks by gaurs (Bos gaurus), elephants harvesting plantain and coconut trees, wild boars utilising the cultivated tubers, and bears searching for anything edible. It is not uncommon for deer to end up in cooking pots, resulting in leopards retaliating by feasting on goats, calves, and dogs (!). Similarly, jackals target chickens and there are cases of attacks by tigers too.

In the case of urban wildlife, the boundaries become vaguer. Our family home is located in an area supposed to have been a forest around 150-200 years ago (presumably until a manor was constructed for the Chief Secretary of the government). Since then, it has been transformed into a sector of houses (both old and new), most having limited grounds (those which do have what is termed ‘well-maintained’ grounds, i.e. backyards devoid of trees).

In this instance, I cannot state that humans have ejected the resident wildlife out of their territories- such an event would have happened quite a while ago. The area is still frequented by numerous local and migratory bird species, including kingfishers (who were very fond of our outdoor fish ponds), crow pheasants, kites, kestrels, pigeons, cranes, and herons, as well as palm civet (Paradoxurus hermaphroditus), mongoose (Herpestidae), squirrels, and bats (to name a few). But such peaceful coexistence is not the norm. A neighbour has made the full use of urban wildlife by laying traps for civet cats and mongoose, both of which end up either in his cooking pan or sold for high prices to vendors of quack medicines (civet cat meat is supposedly a cure for asthma).

Snakes tend to reach deplorable ends, regardless of their nature (poisonous or non-poisonous). Even the rat snake (considered to be auspicious) suffers a terrible plight due to mistaken identity. In our grounds, we’ve had kraits (Bungarus coeruleus) and vipers, apart from a regular ‘visitor’ of nearly four decades- a 6-foot hefty cobra (Naja naja). But recently, after being burdened by just too many reports of snakes nesting in an aged clump of golden palm trees in our front garden (next to our verandah), the parents uprooted the thicket and found, to their surprise, a huge nest of vipers. This brings one to the question- where does one draw the line?

Mongoose caught in the trap of our neighbour

Ariel the lion

There has been some degree of e-interest in the case of Ariel the lion. Ariel is a three year old, 140-kg lion, born in Brazil, in an animal shelter belonging to Raquel Borges. Unfortunately, a year ago, what started as a minor case of limping, within days culminated in an inability to move his hind legs. After a surgery to remove a herniated disc, he lost control of his front legs as well.

Tests failed to diagnose anything and veterinary neurologists from the Hebrew University are to publish their results on Ariel's case later this month. Some hypotheses have been voiced: a debilitating virus, a degenerative/autoimmune disease (potentially affecting his medulla causing the WBCs to attack the normal cells). Other potential causes could be Lactate Dehydrogenase-Elevating Virus which causes extensive destruction of motor neurons (Contag and Plagemann, 1989). One previous study communicated progressive hind limb ataxia, loss of proprioception, and eventual recumbency in five adult cheetahs in an Austrian zoo (Walzer and Kübber-Heiss, 1995), all of which had massive demyelination in their spinal cords. Interesting, the local zoo here in Trivandrum has also battled similar cases (in a leopard and tiger) and similar incidents have been reported in the forests.

His carers have launched a Facebook campaign and website to raise money towards his treatment and upkeep (circa $11,500 per month).

It was illuminating to read some of the responses from the readers, most of whom opined that the owners were cruel and selfish in keeping Ariel alive. As is the viewpoint of many an owner of pets, the consensus edged on euthanising Ariel. Indeed, the animal is in a terrible plight and I commend those who take such diligent care of him. But having been a pet owner for over 25 years, I empathise that it is exceptionally hard to put down a dear pet. Many of my pets (mostly rescued), over the years, have been down similar routes when vets would completely wash their hands off. In many a case, TLC, medicines, perseverance, and patience led them to complete recovery.

Contag, CH and PGW Plagemann (1989). Age-Dependent Poliomyelitis of Mice: Expression of Endogenous Retrovirus Correlates with Cytocidal Replication of Lactate Dehydrogenase-Elevating Virus in Motor Neurons. Journal of Virology, 63 (10), 4362-4369.

Walzer, C and A Kübber-Heiss (1995). Progressive Hind Limb Paralysis in Adult Cheetahs (Acinonyx jubatus). Journal of Zoo and Wildlife Medicine, 26 (3), 430-435