GET TO KNOW THE BIRDS OF TURKEY - 4
Northern bald ibis - Geronticus eremita (Kelaynak in Turkish)
This species has undergone a long-term decline and now has an extremely small population, with over 95% of truly wild birds concentrated in one subpopulation in Morocco. Numbers are currently increasing owing to management actions and consequent improved breeding success. However, this improvement in its status in Morocco is very recent and has not yet led to an increase in the number of colonies. In Syria its population appears to have declined dramatically in the past 30 years. The species is precautionarily retained as Critically Endangered for these reasons.
70-80 cm. Large ibis. Black overall, with iridescent tints of blue, green and copper in sunlight. Red, naked face and crown. Long, narrow feathers project from nuchal area to form ruff. Voice Usually silent. Various hisses and grunts at nest and in display
Distribution and population
The historical range of Geronticus eremita probably extended throughout North Africa and into the Middle East. Since the beginning of the 20th century, however, the species has been known from two disjunct populations: a western population in Morocco and an eastern population in Turkey and Syria. In Morocco it is found at Souss-Massa National Park (338 km2; three sub-colonies) and at nearby Tamri (one colony, half the breeding population), with some movement of birds between these two. The eastern population was believed to have died out, however, in 2002, a tiny colony, consisting of just seven individuals, was rediscovered at Palmyra in Syria. Being migratory, the Syrian population is behaviourally distinct from the Moroccan one, with which it is thought to have separated long ago. During the six breeding seasons following the rediscovery (2002-2007), the three, and then two, pairs breed well and a total of 24 chicks fledged and left the breeding area successfully. Between 2004 and 2007, five immature ibises returned to the colony. In 2008, breeding failed with four chicks dying, probably due to predation by Brown-necked Raven Corvus ruficollis. The causes of failed breeding in 2009 are uncertain, but intraspecific disturbance and low spring rainfall are possible factors. In 2011, a single breeding pair fledged two young. Searches in 2003 for further colonies within the Syrian steppes proved fruitless. Satellite-tagging has revealed that this population migrates south through Jordan and Saudi Arabia; six birds spent three weeks in Yemen (July-August), then wintering in central Ethiopia; migrating back to Syria, through Eritrea, Sudan, Saudi Arabia and Jordan in February; four adults were located in Ethiopia in the winters of 2006-07, 2007-08 and 2008-09. Records of untagged birds in Israel and Djibouti in late 2007 may relate to immature birds from the Syrian colony or birds from an as yet undiscovered population. In 1995, the Moroccan population was estimated at 300 individuals (74 breeding pairs that laid eggs). In 1998, it had declined to 59 pairs, following the mysterious death of 40 birds in 1996, but by 2006 there were 95 pairs that laid eggs. Importantly, since 1980 there has been no overall decline in numbers at Souss-Massa NP. Growing numbers, and good productivity (over 500 birds in the Moroccan population after the breeding season in recent years) give cause for optimism that former areas may soon be recolonised. A semi-wild population numbering 91 individuals in 2006 exists at Birecik, Turkey, where birds are free-flying for five months, breeding on natural nest sites and nest-boxes on cliffs, but are taken into captivity after the breeding season to prevent them from migrating. Three birds from the colony migrated in 2009 travelling via the Palmyra site. However, three were found dead in Jordan. Historically, the species occurred across parts of southern Europe, and captive populations have been maintained in Austria (at Grünau, 22 birds, now breeding) and Spain, with a long-term aim to re-establish the species in parts of its former range. Around 30 birds have now been released in the La Janda area, Spain, and in 2008 a released pair laid two eggs, perhaps the first breeding of the species in the wild in Spain for 500 years
An unquantified decline is indirectly estimated to have occurred over the last three generations. The Moroccan population has been stable since 1980, however Serra (2003) provides reasonable evidence, including testimonies of local people, that in Syria the species was still common 20 years ago and possibly quite abundant 30 years ago. Colonies of several hundred probably existed up until 1980. Although the Turkish population may be now recovering to levels it was at ten or more years ago, this heavily managed population is excluded from the overall trends.
It has declined for several centuries, perhaps partly owing to unidentified natural causes. However, the more recent rapid decline is undoubtedly the result of a combination of factors, with different threats affecting different populations. In Morocco, illegal building and disturbance close to the breeding cliffs and changes in farming on the feeding grounds are the threats that may have the most severe impact on the population. Hunting is the main threat to the tiny Syrian population, and overgrazing and collecting of firewood have reduced habitat quality in feeding areas. A well was under construction at a main feeding site in Syria in 2007. This is likely to increase disturbance to the species and might render this important site unsuitable in the near future. Disturbance from other human activities is on-going, and this population is also potentially threatened by trophy hunters, combined with a lack of safe areas with water sources. The integrity of the protected area at the Syrian breeding colonies is potentially threatened by oil concessions, infrastructure development and plans for urbanisation. Satellite tracking of juvenile birds indicates that the main threat to the eastern population is mortality from hunting in the Arabian Peninsula. Three birds tagged in summer 2010 did not survive their first winter. Breeding productivity in Syria in 2005 was zero: local rangers reported predation as the cause. In Turkey, a major historical threat was poisoning and reduced breeding success caused by pesticides used against locusts and mosquitoes. In Syria, the most serious nest predator is Brown-necked Raven Corvus ruficollis, however, predation by Egyptian Vulture Neophron percnopterus on young ibis chicks is also suspected. The Birecik population has also suffered from losses to predation in some years. At Souss-Massa NP, the most recent causes of breeding failure have been loss of eggs to predators and, more importantly, poor chick survival as a result of starvation and predation. A proposed tourist development at the national park could prove detrimental to the birds if it is not constructed in a sensitive way. Poisoning was suspected to be the cause of death of three tagged individuals found in Jordan, however electrocution whilst standing on electricity pylons is now believed to have been the most likely cause.
Wikipedia - www.wikipedia.org
Birdguides - www.birdguides.com
Trakus - www.trakus.org
Birdlife International – www.birdlife.org
Hope to meet you again with a new species next week.
Photo credits: Caglar Gungor.