Category Archives: Ants

Fascinating stuff about Ants & Vultures

Ants

This morning I was searching around the internet for information about ants as I am interested in identifying the species of those that I have seen lately both in Pinar del Rey and in Jimena last week as their behaviour was quite different, the former colony were taking seeds into their nest, the latter insects.

On our recent outing to Sierra de las Nieves I had already asked one of the gonhs team, an entomologist, what he thought the former lot were up to and he explained that these would be Harvester Ants gathering grass seeds for their food stores. The workers doing the actual harvesting take back grass seeds whole, i.e still enclosed in a protective sheath.Once back at the nest the grain is extracted from the husk and taken in either to be stored or to be fed to the Queen or developing larvae. The unwanted parts are then discarded. He didn’t know why the beetles may have been there, but speculated they may have been finding food amongst the detritus. I have put the picture in again as a reminder (click on it to enlarge).

An intriguing scene involving ants, their harvest of grass seeds and beetles

I am assuming then that these are Harvester Ants of the species Messor barbarus. I learnt more interesting stuff about these ‘granivorous’ ants, including the important role they play in seed dispersal.

The other insectivorous group (Jimena) were harder to pinpoint down, but I think they may be Argentine Ants, a species that has apparently spread all over the world. I checked the Iberia Nature website for anything they may have on ants in Spain and although I didn’t find what I was looking for I came upon this article, it is so amazing I have to share it:-

Unicoloniality and supercolonies

Most commonly, ants from different nests exhibit aggression toward each other. However, some ants exhibit the phenomenon called unicoloniality, where worker ants freely mix between different nests. A group of nests where ants do not exhibit mutual aggression is known as a supercolony — this form of organization is known as supercoloniality, and ants from different supercolonies of the same species do exhibit mutual aggression. Populations in supercolonies do not necessarily span a contiguous area.

Until 2000, the largest known ant supercolony was on the Ishikari coast of Hokkaidō, Japan. The colony was estimated to contain 306 million worker ants and one million queen ants living in 45,000 nests interconnected by underground passages over an area of 2.7 km2 (670 acres). In 2000, an enormous supercolony of Argentine ants was found in Southern Europe (report published in 2002). Of 33 ant populations nested along the 6,004-kilometre (3,731 mi) stretch along the Mediterranean and Atlantic coasts in Southern Europe, 30 belonged to one supercolony with estimated millions of nests and billions of workers, interspersed with three populations of another supercolony.The researchers claim that this case of unicoloniality cannot be explained by loss of their genetic diversity due to the genetic bottleneck of the imported ants. In 2009, it was demonstrated that the largest Japanese, Californian and European Argentine ant supercolonies were in fact part of a single global “megacolony”.

Another supercolony, measuring approximately 100 km (62 mi) wide, was found beneath Melbourne, Australia in 2004.

http://news.bbc.co.uk/earth/hi/earth_news/newsid_8127000/8127519.stm

Vultures

In the previous post I mentioned seeing a whole flock of  Griffon Vultures that appeared to be circling over what I assumed to be food. Whilst on the Iberia Nature website, reading ‘Nick’s blog’ I came across this bit about Vultures and their problems finding food, complete with the fantastic photo:

Accompanying following article- original source unknown

18th Oct 2010 – A new Spanish study has highlighted the role played by vultures in reducing energy consumption in Spain, saving the annual energy use of an estimated 9,000 homes and preventing 193,000 tons of CO2 from being released in the atmosphere. Spanish livestock farmers produces 380,000 tons of carrion, whose incineration involves a high energy cost. An adult vulture consumes some three kilos of meat a week, with all vultures in Spain consuming some 10,000 tonnes a year. Unfortunately the strict EU rules, as a result of mad cow’s disease, force many farmers to incinerate dead animals in official centres at a high cost to both them and in terms of CO2 production. I’d be interested in knowing how much CO2 the vultures would save if and when the EU rules are eventually relaxed.

This is a precis of a report on another blog (La Cronica Verde): (link also on my front page)

http://blogs.20minutos.es/cronicaverde/2010/09/27/los-buitres-ahorran-tanta-energia-como-9-000-familias/

Further discussion from Birdlife International on how they believe the EU rules could be changed:

http://www.fida.es/…/BirdLife%20Amendments%20to%20Commission%20proposal%20on%20.

Sunday afternoon in a pine forest

Pinar del Rey – The King’s Pine Forest, lies to the north of the town of San Roque. It was planted in 1800 by the Spanish Navy to provide timber for building ships; the planting consisting of a combination of Stone Pines and Cork Oaks. In 1804, following the defeat of  the combined navies of Spain and France at the Battle of Trafalgar, the Spanish no longer needed the timber and the plantation was gifted to the people of San Roque by King Ferdinand VII as compensation for losing Gibraltar 100 years earlier.

A path through the pine trees

The area has long been used by the local people as a recreational area and now there are picnic areas and barbecues set up in cleared areas beneath the trees, some of them quite extensive. The shady woods are a lovely outdoor ‘breathing space’ for families living in the local towns and villages, and are probably the most popular nature spot for miles around. Many families spend a day out in the country here, and it is especially busy on a Sunday, the traditional ‘family’ day.

On Sunday outings I normally steer clear of any area I know to be a popular family venue. Today, feeling in need of some fresh air and gentle exercise, and persuading Jon that he did too, I went along with his suggestion to drive out to Pinar del Rey, albeit with some trepidation on my part. It’s not too far from where we live and once through the small town of San Roque you are out in the countryside. It is still green, and colourful now with the tougher flowers of summer, purple thistles, patches of yellow Spanish Oyster plant and the lime green-yellow flowerheads of Fennel. Turning into the entrance to the site it was immediately apparent that although it was by now late afternoon, there were a lot of people here: families sitting chatting around the wooden tables, lingering over their picnics, children playing amongst the trees and people just strolling along the shady pathways. It is great to see folks out and about and making the most of this wonderful public space, but, very selfishly I know, we were hoping for something a little more peaceful where there may be a chance of seeing some of the wilder residents of the area. There is just one paved road for cars that eventually reaches an abrupt end and the only way forward is on foot. That is where we stopped today, in a spot where there were no other cars or people in immediate sight and close to the beginning of one of the marked footpaths, the ‘Sendero de las Aguilas‘.

Stone Pines backlit by the sun with Cork Oaks behind

This is a lovely path, pleasantly shady and the air fragrant with the fresh resinous scent of Stone Pines. A Blackcap was singing, moving from tree to tree as we approached but picking up the song each time he changed perch. I heard a Greenfinch calling and caught sight of a Blackbird, otherwise all was quiet. The track is almost on the edge of the part of the forest dominated by Stone Pines, its edge is marked by a water course bounded by other tree species and shrubs such as Oleander; and beyond it is more woodland comprised mainly of Cork Oaks.

There were several patches of some very pretty and delicate flowers growing alongside the path that I had not seen before, coloured in various shades from pale mauve to purple and magenta.

The little purple flowers are held on very thin stalks

I discovered later that the plant is  a Campanula (Campanula specularioides). Apparently it got its latin name because of its similarity to the flowers of Venus’ Looking-glass, (sp. Legousia), which used to be called Specularia. (Betty Molesworth Allen).

A patch of campanula with bigger flowers showing several variations inn shade

While I was busy with the flowers, Jon discovered a very intriguing scene that was being acted out on another part of the forest floor; where ants were milling around a large hole and running back and forth over a pile of freshly excavated soil.Some of them were actually carrying grass seed heads and there were a great number of similar seedheads piled around the edges of the soil pile, clearly harvested by the ants, that were either being carried into or out of the hole.Perhaps the oddest thing was the presence of four beetles, a couple of which were being harassed by ants, while others seemed to be burrowing into the piled up seedheads.

An intriguing scene involving harvesting ants and round-bodied beetles

Meanwhile, up in the trees a Crested Tit foraged around the pine cones. These lovely little birds are one of the most elusive species for me in terms of getting photographs and today was no exception. It was too shady there to get a decent picture anyway as I discovered when I attempted to capture an image of a pair of Blackcap in another treetop. A Jay was a little more obliging, sitting halfway up a better-lit trunk.

Jay - Garrulus glandarius

We heard a Robin singing and spotted him perched on a low branch next to the path, flying off as we approached.

A very large old Stone Pine with a double trunk

Many of the pine trees are huge specimens that are reputed to be those originally planted in the early 1800s, they are impressive and beautiful and present countless opportunities for photographs; the light and shade on the trunks, the textures of the bark, the sunlight filtering through the canopy and so much more. Part of the track runs parallel to the river bank and the damper conditions here support a different flora, amongst which is the dramatic Acanthus. It is not a common plant in this area, except on calcareous outcrops, but it is often cultivated, so I am unsure if it would have occurred naturally here.

Acanthus leaf with greenbottle fly. The leaves of this plant were patterns for the design on capitals of many Corinthian pillars of the ancient world.

Acanthus mollis - flower. The common name of Bear's Breeches comes from the shape of the flowers.

The shape of the top of the tree gives it the common name of Umbrella Pine

We took a different route home as I was keen to see the progress of the Stork families, so at the entrance/exit to the park, rather than turning left towards San Roque town, we turned right to go to San Roque Estacion. This is a very quiet road, particularly since the new stretch of dual carriageway was constructed, and is not in very good repair, but it is much more scenic and tuneful too – we must have heard at least half a dozen snatches of Nightingale song as we passed by. We saw a Nightingale too, very unusually perched on a power cable near the junction of this road and the new one. We saw Storks on their nests from here too where the road crosses the railway line, but had much better views once on the road driving towards Jimena. Most of the nests had at least two or three grown-up young, and many were crowded with the whole family jammed in at once.

This is always a busy road, but we risked a very quick stop so I could take this photograph:

Parent White Storks with their grown-up young. The adult hiding her face at the back and looking a bit tatty is most probably the mother!