Mr Wolf, I presume?

Yes, appalling as it sounds, I read the Trinity edition of my alumni magazine only now. One of the stories (pg 13) caught my eye for various reasons.

Those of us who have a long-standing interest in Egyptian mythology would recall Anubis, the jackal-headed god of the dead, who held the unappealing portfolio of funerals, afterlife, mummification, fate of souls, and protection of the dead and their tombs. This was presumably because Anubis’ animal counterpart, the Egyptian Jackal (Canis aureus lupaster; Hemprich and Ehrenberg, 1833), preferred to occupy burial grounds. C.a.lupaster was considered to be a large, rare subspecies of the golden jackal (Canis aureus; Linn. 1758) even though there has been a historic (ahem) bone of contention over whether it is a jackal or a wolf (given its wolf-like morphology). Ancient Greeks considered these to be smaller versions of the European wolves; evolutionary biologist Thomas Huxley, after comparing the skulls of C.a. lupaster and Indian wolves, considered the species as grey wolf; Walter Ferguson (1981) argued that it was a species of wolf after studying its cranial measurements.

But research published earlier this year by collaborators from Oxford University's Wildlife Conservation Research Unit (WildCRU), University of Oslo, and Addis Ababa University has established the Egyptian jackal’s true skin. When the mitochondrial DNA of the Egyptian jackal was compared with that of the golden jackal, wolves, and wolf-like canids, the results demonstrated that the Egyptian jackal (whether in Egypt or Ethiopia) is (and should be renamed as) an African Wolf, a subspecies of grey wolf or a separate species in itself, which existed alongside the golden jackals and the rare Ethiopian wolf (Canis simensis, an unique but endangered species). Furthermore, sequencing of mtDNA from Ethiopian highland golden jackals revealed that these were, in fact, Egyptian jackals (i.e. the African Wolf). African wolves are closely related to the Indian (Canis lupus pallipes) and Himalayan wolves (Canis lupus chanco- with 2.4% divergence).

What does this bode for the species? The authors of the PLoS study called for assessing the status of the African wolf. Its previous classification as a subspecies of golden jackals meant being listed as a species of least concern by the IUCN. But since this is now the only grey wolf species in Africa, this could be rare and endangered.

References:

Rueness EK, Asmyhr MG, Sillero-Zubiri C, Macdonald DW, Bekele A, Atickem A, & Stenseth NC (2011). The cryptic African wolf: Canis aureus lupaster is not a golden jackal and is not endemic to Egypt. PloS one, 6 (1) PMID: 21298107

Oxford University's Press Office

WildCRU

Image: Golden jackal by Stig Nygaard

More scientific grub on migration

A previous post presented how those characteristic summer chorus of the English countryside may be soon an event of the past. This rapid decrease in the population of migratory birds in the UK was attributed to habitat destruction and other such anthropogenic factors, probably somewhere along the migration corridor. So what does habitat destruction and other anthropogenic influences bode for migrating organisms? Vishwesha Guttal and Iain Couzin, of Princeton University, try to predict this (amongst other interesting stuffs) via models explained in their paper on ‘Social interactions, information use, and the evolution of collective migration’, an interesting read, although a tad too technical for the layman.

Organisms, all along the phyla of the animal kingdom, are believed to migrate as a result of detecting and responding to factors governing resource availability. The foundational theory considers each migrating individual as “‘information processing units’, with interactions amongst them providing collective benefits”, such as improved migratory direction. Should an individual commit an error in the information processing, the aforementioned grouping would average the individual measurements, so as to deduce the mean migratory direction.

These migrating populations have two types of individuals:

-Leaders, who have a higher ability to detect and respond to directional gradient from the environment, but with weak (or none) social skills. They tend to occupy frontal or peripheral positions and expend more energy in trotting off the beaten track and facing dangers such as predators.
-Social individuals, who have strong social skills but weak ability to detect and respond to gradient. However, they utilise the strengths of the leaders for a free ride.

Population density, according to the model, is a crucial leverage factor. Extremely low-density populations (ergo, lesser probability of encountering others) comprises of leaders, thus resulting in solitary migration. Extremely high-density populations results in resident population due to a lack of migration (attributed to frequent ‘collisions among individuals’). It is when leaders and social individuals coexist that collective migration ensues. The bottom-line is that ‘the evolution of the migratory strategy (resident, solitary, or collective) is determined by the ecology of the species (i.e population density, habitat structure, costs and benefits of migration)’. Presumably, there could be other regressors as well....

Anthropogenic factors have been exerting pressures (such as habitat fragmentation and changes in population density) on the existence of many migratory species (examples cited in the paper includes: American bison and its steep decline in its population density; extinction of passenger pigeon) and migratory patterns (Blackcaps becoming resident; Eastern house finch exhibiting the reappearance of lost migration). As habitat fragmentation increased, the individuals adapt their migratory strategy by travelling longer distances to find an appropriate habitat. The researchers’ model predicted that in such cases, paradoxically, the population’s migration ability reduces relatively gradually with increasing habitat fragmentation. The reasoning is that: ‘at high levels of habitat fragmentation, no individuals evolve to be leaders, and therefore, the population loses its migratory ability. Even after restoring the habitat, a population’s migratory ability does not recover at the same habitat quality at which it declined due to the relatively short time scale of these changes’.

Guttal V, & Couzin ID (2010). Social interactions, information use, and the evolution of collective migration. Proceedings of the National Academy of Sciences of the United States of America, 107 (37), 16172-7 PMID: 20713700


Image Source: The Wandering Angel

Now potted plants. Next what?

When I read about Goldman Sachs’ HQ in London kicking out ‘pot plants’, as part of a cost-cutting measure, my first reaction was to conjecture how ‘pot plants’ ended up in the investment bank! Jokes apart, Jonathan Sibun (Daily Telegraph) writes that the bank is evicting potted plants since, apparently, many £££s per annum is spent on purchasing and maintaining these plants (I haven’t ever been to the Goldman Sachs HQ, so I haven’t a clue what these plants are- expensive orchids? 10 ft tall palms?). This measure has met opposition from some of the staff who tried to prevent their expulsion. The article goes on to state that,

‘In some cases, a solution is believed to have been found only after employees agreed to sign forms guaranteeing to take responsibility for particular plants. Many of those plants that were removed are believed to have been given to charities’ (wonder which charities are richer by several potted plants?).

Is there truly the need for such a drastic measure? As is the practice in many offices, employees could have brought their own plants to instil some life in the workplace. Alternatively, employees could maintain the plants- one glass of water per day should suffice, I think. Nothing as demanding as playing with money.

If Goldman Sachs is so keen on cutting overheads, I can think of a few measures which would also help the environment at the same time. But I wonder whether, in time, the bank’s purported CSR practices would be relegated to the backburner as part of these cost-cutting initiatives.

Source: http://www.telegraph.co.uk/finance/newsbysector/banksandfinance/8712286/Pot-plants-in-firing-line-as-Goldman-Sachs-cuts-costs.html


Image Source: © Zak Kendal/cultura/Corbis

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