Valdeinfierno, Los Alcornocales, Woodland flowers and Birds 11th May 2013

Valdeinfierno (Los Alcornocales)

Michael Tiedtke

Mediterranean Flora is often associated with a climate of long dry summers and cool wet winters. However, the large diversity of plant communities encountered in Andalucia can only be explained by other additional factors such as high variability of soil types (eg. acid or basic), altitudes, distance from the Atlantic,total annual rainfall ranging from the driest area in Almeria with north African type of flora to wet areas with rainfall in excess of 1000mm (per annum) in the south west Grazalema and Los Alcornocales Natural Park)  where higher altitudes are often shrouded in mists. Here and along rivers we find a lauroid wood similar to that of the moist areas of the Canary Islands with laurel (Laurus nobilis) ferns (eg Davallia canariensis) liverworts,mosses and lichens. On slopes where the forest Cork Oaks have dissappeared, heathland plant communities which are unique to this area have evolved due to its moist Atlantic conditions. This heathland resembles those from Britain but despite the high rainfall is typically Mediterranean with many plants being either spiny or having very small leaves and an altogether small biomass, reflecting the adaptation to the poor soil and hot dry summer. Many plants are endemic to the south west of the Mediterranean, while a few have a larger area distribution. the heather plant community of the Alcornocales has recently been studied by Perez Latorre, gavira and Cabezudo. (2007 Ecomorphology and phenomorphology of Mediterranean heathlands ( SW  Iberian Peninsula) Phytocoenologia 37(2),329-268.

The Valdeinfierno walk starts at the dirt track off the road C4440a at 81km and parking is under a few cork oaks after approximately 1km driving on the track.
Our walk leads first through heather, the dominant shrubs are Heather (Erica) Gorse (Ulex, Stauracanthus) and Cistus. Descending to the river (Arroyo Valdeinfierno) we walk first through woodland dominated by Cork oaks, that is typical for semi dry conditions. The vegitation along the river is determined by high humidity and mild temperatures throughout the year, typically lauroid in character (non deciduous trees and shrubs with glossy often rather large leaves) which is in strong contrast to the heathland as mentioned above. We finish the walk going back along the dirt track where we will see a few wild Pear trees and some Orchids.

Our walk 

Jill yeoman, photos Clive Horrocks

As we approached Valdeinfierno along the sandy track we were greeted by a bee eater circling overhead, we parked and quickly one of the party spotted a Common Redstart siting in a nearby tree, we also saw probably the same bird at the end of the walk this time with food in its beak so probably busy feeding young nearby.

We started our walk heading out over open ground where Micheal quickly pointed out the Insect Trapping sundew Drosophyllum Lusitanicum a pretty yellow flowered plant that can survive on this poor sandy soil by trapping insects on its stems using extremely sticky dew that traps the insects enabling the plant to gradually absorb them so norishing the plant.

Before the path took us gradually down into the river valley we had good views of a buzzard circling overhead on the path we spotted the gorgeous  Large Tongue Orchid Serapias Cordigera

Close by we also found an excellent specimen of  Spotted Rockrose Tuberaria Guttata with its pretty  primrose colour flowers with brown spots in the center.

We are now moving into woodland hearing Iberian Chiffchaff, Willow warbler and Chaffinch calling all around us, here we also encounter the babbling fast flowing river where Wrens are shrilling and a distant Wood Pigeon is cooing. Micheal pointed out a Royal Fern Osmunda Regalis growing in the crevice of a large boulder close to the river.

We stopped near a tributary stream where Michael pointed out Apium Nudiflorum Fools Watercress, we declined to try this but smelled the pungent fumes of Allium tributum Wild garlic with its unusual triangular stem. Suddenly close by we could hear the call of a Tit and on closer examination a Crested Tit was spotted in the canopy above us.

Continuing along the stream one of the group pointed out a small bird crouching on a cork oak branch at the side of the water, we could see its wings and back as it preened after its bath, and then it hopped up and gave us a bright red flash of its Red breast after this sighting suddenly the whole area seemed to be alive with robin song and calls. Another member also pointed out a very large spider hanging over the river on its strong web.

We continued through the dappled woodland following the river some of the group climbed up a leave covered slope and after a while of poking around carefully with sticks were able to find two different fungus species Russula Piperata similar to chanterelle but with a peppery taste allegedly we didn't try it and a Lactarium named as it produces a milky white liquid when you break the stem.

We also had good views of a short toed tree creeper probing into the bark of a cork oak and pulling out an insect. Other birds heard and some seen included Great Tit, Nuthatch, Willow warbler, Iberian Chiff, Blackbird and Blackcap, we also had some good views of jays flitting through the tree tops. some of us were also lucky to spot a Crested Tit 

As we came out of the canopy of the woodland we emerged into a clearing and were greeted by an expanse of wild flower meadow with lots of butterflies collecting nectar, Clouded Yellow, orange tip, speckled wood and meadow brown were some identified. Also spotted was the  Bee Beetle Trichius fasciatus We also suprised a female Pied Flycatcher who was hawking flies a near by branch.                    

Bee Beetle Trichius fasciatus

Meadow brown

Speckled wood

After a drink in the shade of some large oaks we started our walk up the road in the direction of the parked cars, all along the road side were many wild flower species, Michael was very excited when he spotted an Epipactis with its small deep red flowers looking to be wilting but are actually fresh growing in quite shady woodland at the road side. Here we saw another jay and heard nuthatch calling once more. We had good views of a pair of Short toed Eagles displaying and a Booted Eagle light phase.

A loud blast of machine gun trill made us search a cork oak as we walked close by and we were rewarded with excellent views of a Bonelli's Warbler busily searching through the leaves, and later a few of us who had hung back to enjoy this also caught fleeting views of a Fallow deer running down and across a fire break and crashing into the undergrowth and out of sight in seconds. Continuing on along the path as the edges opened up we were treaed to lots of bee Orchids and large groups of small Tongue orchids many unfortunately almost over, but still spectacular and well worth a visit next year.

During the drive back to the venta for our lunch we had a quick stop to look at some beautiful unusual bog type flowers and suddenly the air was full of Griffen vultures giving us stunning close up views, later we were treated to the songs of Nightingale, Serin,and Corn buntings as we drove.

The gang

SIERRA BLANCA - Mountain flowers and birds

Saturday 28th April

With a slightly worrying weather forecast (precipitation 3mm 60o/o chance)

13 hardy individual GONHS members arrived at La Refugio de Juanar after a drive up into the misty Sierra Blanca hills just past the white pueblo of Ojen taking the winding track leading to the Refugio we were treated to the bright pink blooms of Echium albicans.  Alas we needed our rain jackets and umbrellas to get to our coffee.

                                                            Echium Albicans

After a lovely leisurely breakfast of cafe, toastada and fruit cake, at the Refugio we emerged into sunshine to commence our walk. Sadly due to the damp terrain it was decided that we would not take the planned path up the steep and now slippery path to the summit but the less demanding flat circular walk towards the view point.

                                                      Bee Orchid

We were quickly shown a yellow bee orchid growing close to the path by Michael our botanical expert and also enjoyed the beautiful chestnut blossoms of a small copse, some of the hardy ones of the group scrambled up an incline for more flora whist others enjoyed fleeting views of robin, great tit and cirl bunting, the woods were alive  with bird song, mostly chaffinch but also cirl buntings and wren were heard.

We wandered on up around a bend towards the plateaux and heard the distinct sound of firecrest high above us in the pine trees, Jill managed to see them and point them out as they flitted  busily from branch to branch.

Once onto the flatter terrain of open maquis a jay flew behind us and hopped through the branches of an olive tree and we enjoyed a group of Tassle hyacinth's and saw plenty of the taller Reseda barrelieri.

   
       Tassle Hyacinth                                                                     Reseda Barrelieri

                                                         

We took a left hand path heading towards the direction of the coast the rain holding off but a chilly easterly wind keeping us moving, Linda was lucky to spot a beautiful tightly closed roosting small blue butterfly sadly the only one of the day, in more clement weather this area is abundant with butterflies.

We headed into a pine forest with blue, great and crested tits calling around us and reached the first of the breath taking view points with Marbella and the Mediterranean  spread out below us the mist clearing just enough. We continued up to the official viewpoint and enjoyed more views and some beautiful Cistus monspeliensis. Alas the chilly easterly and a few large spots of rain had us hurrying back to the shelter of the pines

Cistus Monseliensis                                                   Pallensis Spinosa

We circled our way back towards the main path and continued on the track to other viewpoint this time looking down the coast towards the straits and Gibraltar but as the advance group approached it they found the winds very cold and retreated quickly so we decided to take the more sheltered track into more sheltered woodland. Here we were quickly rewarded with the most spectacular views of clumps of the beautiful and enchanting Narrow-leaved Orchid (Cephalanthera longifolia) they were tall and looked like jewels amongst the damp rusty colour pine needles covering the forest floor. In these woodland we had great views of chaffinch a pair of busy nuthatch and noisy blackbirds and some of us heard a distant but distinct drumming of a great spotted woodpecker. We also found a mirror orchid ( so called as it has the shape of the wicked queens mirror in snow white)

                                             Narrow Leaved Orchid

Mirror Orchid

On our return walk we were treated to great views of a perched booted eagle (light phase) taking flight at our approach and circling above us and also a cheeky jay hopping around the base of olive trees gave us good views of it's beautiful distinctive plumage.

We got back to our cars and although a bit chilly were grateful that the rains had stayed away for us, some of the group then made our way to a nearby venta where we had a lovely, entertaining and very inexpensive lunch.

This area with its lovely mountain walks and spectacular scenery is highly recommended and we will certainly be doing it again in hopefully more clement weather.

Text Jill Yeoman           Photos Linda Maley

The Flora of the Sierra Blanca: a brief account of its diversity    Michael Tiedtke  

    The Mediterranean vegetation evolved as a result of climate change from a tropical to a Mediterranean climate with long dry summers and cool wet winters. The preceding vegetation consisting of Laurophyll trees, palms etc. now exists only as relicts in Macaronesia (Canaries, Azores and Madeira) and the southwest corner of Andalucia (e.g. Laurus nobilis). In Mediterranean regions, the ensuing widespread dense forests of Holm oak (Quercus ilex subsp. rotundifolia) largely disappeared mainly due to fire, animal grazing and agricultural and forestry purposes. This is also evident in the Sierra Blanca, where large areas are now covered by olive groves, pine forests (Pinus radiata, P. pinea and P. pinaster), Sweet Chestnut (Castanea sativa) and Eucalyptus globulos as well as by maquis (a dense community of small trees and shrubs less than 3m high) and garrigue (a more open community of small shrubs less than ½ m high).

    Most of the Sierra Blanca, particularly at higher altitudes, consists of calcareous rocks ranging from limestone to dolomite. Silicate soil conditions occur at lower altitudes favouring quite different plant communities adjusted to more acid soil conditions.

    A sustainable plant (and animal) diversity depends crucially on the size of the habitat area as described by Wilson in his book on ‘The Diversity of Life’. The Sierra Blanca cannot be regarded in isolation but has to be seen as part of a larger mountain range with similar soil conditions comprising the adjacent Sierra Mijas, Sierra de Las Nieves and Sierra Grazalema, which to a large extent share the same population of plants. The rich diversity of the flora comprising over 1000 species of vascular plants may be due to several reasons: the absence of a permanent ice cap during the last ice age ending ca. 10,000 years ago, the Mediterranean climate, a variable range of altitude and soil conditions, the replacement of monotonous uniform forests by more open types of vegetation and the introduction of species from other areas of Spain mainly by dispersal of seeds by wind, birds etc. Diversity is particularly high on calcareous rocky slopes, where only some small trees grow due to poor soil quality as a result of erosion, thereby promoting the growth of a large variety of shrubs, perennials, annuals and bulbous plants e.g. the majority of the over 30 orchids observed in the Sierra Blanca. Some plant families are particularly well represented such as Cistaceae (considered the typical Mediterranean family per se with Helianthemum, Cistus etc), Labiatae (Thymus), Orchidaceae (Orchis and Ophrys), Compositae and Scrophulariaceae.

    The Sierra Blanca offers several sign-posted walks across different habitats. The circular walk with start and finish at the Refugio de Juanar (where Charles de Gaulle wrote his memoirs) is most interesting - in particular the east facing rocky slope (first quarter of the walk) which habitats a rich flora of Mediterranean plants.

GONHS would like to thank Michael for this interesting insight of this wonderful region and for his expert guidence during the day. 

Wild Mushrooms in the Alcornocales

Saturday 26th November 2011

This years delayed Mushroom outing once again was well attended, with about 15 gonhs members and 10 guests of our Spanish hosts and Guides Manolo Barcell or Eduardo Briones meeting at the venta, El Frenazo, on the old road out of Los Barrios we sorted ourselves into 4 wheel drives and went deep into the park, further than ever before, where we dispersed into the cork oaks spending an hour or so mushroom hunting and for the birders amongst us getting good views of Griffon Vultures, Booted eagle, Common buzzards, Raven, Robins, Blackcaps, Crested Tits, Chiffchaffs, to name a few. We also found lots of fungi the majority being the wrong kind, but lots of lovely edible specimens were found by our Spanish experts. We gathered together and Eduardo sorted our finds into edible, not so edible and best avoided categories giving us lots of interesting information about the different species, he also explained the importance of using wicker baskets to collect the mushrooms in so that the spores fall through the holes to enable future germination.
   It was now lunch time and although some of our party had to return to Gibraltar the rest of us traveled deeper into the reserve , parked up and our hosts produced from their cars a table, chairs sherry, red wine, chorizo, sheep’s cheese, torta patata, jamon of various types, and we spent a very pleasant time sharing our lunches eating, drinking, and enjoying in the surrounding beauty, we finally packed up and made our way back leaving our Spanish friends to carry on collecting more delicacies.
  The weather was fabulously sunny and mild; the scenery was stunning the company fantastic so a big thank you to all who attended and of course to our hosts.
 Jill Yeoman

Photos by Linda Malay

A day's work at the Bird Observatory

The Gibraltar Ornithological and Natural History Society's Bird Observatory is sited on the Upper Rock Nature Reserve, at Jews' Gate. Its primary function is the monitoring and research into passerines and non-passerines, with particular emphasis on migration.


The research is aided by data obtained through the process of the capturing and ringing of birds by well-qualified ('A') ringers, mainly based in the UK, who volunteer to man the operation for varying lengths of time from a couple of weeks to several months at a time. Trainee ringers looking to gain experience are welcome, provided there is a trainer available or an 'A' ringer to supervise them.There is no resident ringer.It's a popular venue, and bookings must be made to ensure the availability of the accommodation provided. (Bookings are accepted on a 'first come, first served' basis and are managed by Jill Yeoman.)

The Bird Observatory and accommodation facilities are based here at the field centre on the Upper Rock

The building is modest, but the accommodation has everything needed to be fairly comfortable and there's no question that the views it commands are spectacular.

The view from the Observatory doorway, looking across the Bay

Autumn is a particularly demanding time for the ringers in residence, when the migration of a myriad of bird species is at its height and the mist nets may capture dozens of birds that require processing for data. 

A Chiffchaff caught in a mist net

For the ringing operation mist nets are used in an area of Mediterranean matorral dominated by Olive Olea europaea and Lentisc Pistacia lentiscus. The total maximum length of the line of nets is 800 m, with an average of 400m used at any one time. Ringing is carried out on days of suitable weather from February to June and August to November.

Chiffchaff being carefully extricated from netting

A truly beautiful, tiny Serin

The nets are checked in rotation about every half-an-hour or so, the regularity dependent to an extent on the number of ringers present and the numbers of birds being caught. 

A Robin protesting at being held upside down

The welfare of each individual bird is paramount and their handling must be quick, decisive and sensitive.Experienced ringers can extricate a bird from a net in a few seconds; they first assess in which direction the bird was flying when it was caught, then release it by combining the correct grip on the bird with some deft and practised unravelling. 

The nets are very fine but strong enough to support a healthy Song Thrush

A beautiful bright-eyed bird, this song thrush was quite feisty and voiced its protest at the indignity of being caught 

Ian, the current resident ringer carrying in birds

Once a bird has been released it is carefully placed in a cloth bag, where the absence of visual stimuli helps to keep it calm. When all of those caught are collected they are quickly carried back to the Observatory for processing.


The bags are hung from hooks numbered to correspond with the number of nets in use. There are potentially 20 nets that may be 'open'; today there were 18 in use.


The birds are processed methodically and great attention is paid to accurate identification, ageing, measuring, weighing and assessing the general health of each individual, including how much muscle it has and the fat store it has managed to accumulate.


As Ian said, "There is absolutely no point to ringing birds and recording data if it is not 100% accurate."  

Bags of birds

Strings of rings

Bird ringing is carried out under the auspices of the BTO, British Trust for Ornithology, and Gibraltar uses British rings.


The rings are sized with AA being the smallest and C the largest. 


AA ring: Serin
  A ring: Robin, Black Redstart, Blackcap
  B ring: Greenfinch, Woodchat Shrike
CC ring:Orphean Warbler, Song Thrush
  C ring: Cuckoo, Hoopoe

Measuring the length of a Robin's wing

One of today's pages from the data record book

As soon as all required data has been obtained, the birds are set free. Most will set off on their travels and will not been seen again, but a few will stay around for a few days and may find themselves here again, sometimes more than once and will be recorded as a 're-catch'.

A female Blackcap posing for a photograph before flying away

She was reluctant to leave and sat on Jill's open hand for a few seconds

A male Blackcap was much keener to leave

The browner plumage of this well-marked Chiffchaff identified it as northern European 

On a particularly 'heavy' day there may be between 200-250 birds to process. This morning 113 were recorded, mainly Black Redstart, Blackcap, Robin and Chiffchaff with many juvenile birds making their first migration. There were also a few Song Thrush and a beautiful male Serin.


Visitors are welcomed at the Observatory, but as the welfare of the birds is the primary consideration of the working ringer, this must be respected. Most ringers prefer to work as quietly as possible as undue noise will disturb the birds. They may also be very busy and prefer not to be distracted from their work, so be prepared to be asked to be quiet, or even asked to leave the building.