Artificial Nesting Structures for Eurasian pelicans · of pelicans, mainly due to successful conservation measures in some key places (e.g. Prespa and Amvrakikos, Greece), has led

Artificial Nesting Structures for Eurasian pelicansA decision-making and guidance document

Giorgos Catsadorakis

Lake Kerkini National Park, Greece. © Steve Mills / Birdwing

Artificial Nesting Structures for Eurasian pelicansA decision-making and guideline document

Giorgos Catsadorakis

We are grateful to the following people who contributed greatly to the preparation of this guide by offering criticism, comments and suggestions, photographs, literature and all kinds of information and data: Olga Alexandrou (SPP, Greece), Taulant Bino (Albanian Ornithological Society), Sebastian Bugariu (SOR/ Romanian Ornithological Society), Alain J. Crivelli (Biological Station Tour du Valat, France), Nela Vešović Dubak (Public Enterprise for National Parks of Montenegro), Orhan Gül, Tommy King (USDA/APHIS, USA), Hillary Koll and Steve Mills (Birdwing, UK/Greece), Tanyo Michev and Pavel Simeonov (LeBalkan, Bulgaria), Taej Mundkur (Wetlands International), Theodoros Naziridis (Lake Kerkini National Park, Greece), Andrej Vizi (Natural History Muse um of Montenegro), the Management Body of the Evros Delta National Park, Greece. Julia Henderson (SPP, Greece) edited the text and greatly improved the language of the document.

Recommended citation:Catsadorakis, G. 2017. Artificial Nesting Structures for Eurasian pelicans. A decision-making and guideline document. Society for the Protection of Prespa, Greece.

The MAVA Foundation supports the Society for the Protection of Prespa, including its projects for the conservation of pelicans

ARTIFICIAL NESTING STRUCTURES FOR EURASIAN PELICANS. A decision-making and guidance document

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Both the Dalmatian pelican (Pelecanus crispus) and the great white pelican (Pelecanus onocrotalus) are large, ground-nesting species breeding in the Western and Central Palearctic (Montenegro, Albania, Greece, Bulgaria, Romania, Turkey, Ukraine, Russia, Iran, Kazakhstan, India and Mongolia). From a conservation point of view, the former is listed as “Vulnerable” in IUCN’s Global Red List, while the latter is listed as of “Least Concern”. Their colonies are situated on islands and/or in the interface between marsh vegetation and open water in lakes, river deltas and marshes, as well as in coastal or inland lagoons. They nest colonially on the ground of vegetated or non-vegetated islands, which are either earthen or consist of rhizomes of helophytes, mainly the common reed Phragmites australis. They do not have natural enemies and cases of predation pressure on eggs and chicks by avian predators vary but are usually low (Crivelli et al. 1994). Island nesting deters or prevents terrestrial predators from accessing colonies. However, pelican breeding colonies, being large and easily located, are subject to deliberate or unintentional disturbance by humans. Pelican colonies are additionally threatened by natural or anthropogenic changes to the water levels of the water bodies where they nest, either when the water level rises and floods nesting islands,

or when it decreases and the islands become accessible to terrestrial predators. In addition, nests and eggs, especially those which are low and closer to water, are frequently inundated by wave action during high tides or during storms, or are flooded by rising water levels, which may result in the destruction of nests, eggs and chicks or cause nest abandonment thus decreasing breeding success.Over time nesting islands get degraded through use by the birds, wave erosion, storms, heavy snowfalls, etc. They normally shrink in size,

Background / general information

Dalmatian pelicans nesting on a raised wooden platform, Lake Kerkini, Greece. © Theodoros Naziridis

declining in quality and becoming gradually sub-optimal for the birds, or they completely disintegrate and the birds have to shift to other, new sites (Catsadorakis & Crivelli, 2001). In general, there are a number of requirements that have to be fulfilled in order for pelicans to settle at a site to breed: a. abundance and availability of prey (fish) on-site or on other sites close enough; b. availability of proper roosting/resting sites (safe islands, or coastal open areas with a view around them); and c. safe nesting islands, free of disturbance. Some wetlands may


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fulfil all or some of these requirements. Pelicans will not establish nesting colonies at wetlands where all the requirements are not met. Human interventions in the hydrological regimes of wetlands, in combination with the impacts of climate change, have resulted in the diminishment of the qualities and the value of natural wetlands as pelican nesting grounds. Furthermore, due to alterations in the hydrological regime of natural wetlands, pelicans are continuously forced to search for new nesting sites at artificial wetlands, impoundments and reservoirs; however, these are managed to serve other purposes, which are not necessarily compatible with the optimal nesting and feeding conditions for pelicans. In

recent years, an increase in the total population of pelicans, mainly due to successful conservation measures in some key places (e.g. Prespa and Amvrakikos, Greece), has led many managers and conservationists to try to accommodate these increasing numbers of potential breeders on the one hand, and on the other hand to start thinking of attracting pelicans to begin nesting in wetlands where they occur but they do not nest, or to recolonise wetlands where they nested in the past. In the last few decades, the main management measure applied to maintain satisfactory nesting pelican populations and sufficient breeding success, or to attract pelicans to recolonise a

site, has been the building of artificial nesting structures (hereafter ANS). These have been successfully used since at least 1962 in the Volga Delta, in what is now Russia (Bondarev 1976, Vinogradov et al. 1982), later in other countries such as Greece, Bulgaria and Turkey, and more recently in Romania, Montenegro and Albania. Elevated nesting platforms have also been built and used successfully for other species of pelican such as in Uppalapadu, Andhra Pradesh, India, for the nesting of the endangered spot-billed pelican (Pelecanus philippensis) (http://wikivisually.com/wiki/Uppalapadu_Bird_Sanctuary). However, this species is a tree-nesting and not a ground-nesting species.

The main features of the ideal pelican nesting habitat

• Large wetlands big enough and with sufficient resources (food and nesting substrate) to accommodate a colony of over 50 pairs of pelicans• Available nesting islands not significantly and/or frequently impacted by cold spells, adverse weather, storms, winds and waves• Nesting islands not threatened frequently by sudden and severe fluctuations of water levels; either by suddenly increasing or lowered water levels • Nesting sites free of frequent disturbance by humans, boats, wild animals, aircrafts, etc• Sufficient nest-building material easily available on nesting sites or close to them• Feeding waters with abundant and available prey on site or in adjacent sites at distances less than 50 km, for pelicans not having to spend a lot of energy to access them.• Aerial conditions (i.e. thermals, uplift winds, etc.) favourable to large soaring birds for low-cost movements • Calm and safe roosting and resting sites. Either isolated islands or large tracts of open spaces close to water where an unobstructed 360o view is possible and quick access to open water.


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This document aims to provide an overview of the several scientific and practical issues associated with the building and use of ANS for pelicans. It also aims to provide guidance to managers and decision-makers about when, and under which conditions, they should decide to build such structures. It contains material that is intended to inform and to facilitate the process of decision-making and the solving of dilemmas after the decision is taken, and to help avoid mistakes and wrong decisions about deploying ANS to attract pelicans to breed. This is a document which mainly addresses the requirements of the Dalmatian pelican, but there are also references to great white pelicans and hopefully it may prove useful to other species of pelicans.

Scope and goal of this document

Great white pelican (left) and Dalmatian pelican in full breeding plumage; Lake Kerkini National Park, Greece.© Kostas Papadopoulos


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a. Islands of dredged materialEarthen islands are often created with dredged material to provide nesting and refuge habitats for birds and other wildlife. They range in size from a few square metres to over 0.8 km2, and are typically constructed using pebbles, stones, sand, gravel or soil. These islands may be consolidated using various techniques and materials, or stabi-lised with emergent marsh vegetation. They may be constructed singly or in groups, or they may be used to increase the area of existing natural islands. They have been constructed for American white pelicans (Pelecanus erythrorhynchos) (Yozzo et al. 2004) and Dalmatian pelicans (Crivelli 1996, Pyrovetsi 1997, Crivelli & Naziridis, unpublished).

b. Floating raftsFloating structures, in the form of a raft, usually consist of a frame made from wood or metal. On this frame bands of reeds, or a platform of wooden planks, may be fastened, or a welded wire fence may even be stretched and attached tightly, in the gaps between the struts of the frame. The latter has frequently been covered by a durable synthetic mat, which was further covered with a thin layer of soil, debris and cut reed stems, or a thick layer of reed stems.Special flotation materials, such as empty plastic or metal barrels/drums, or polystyrene cuboids, may be fastened underneath the structure. They have been constructed and used in Russia, Bul-garia, Romania, Montenegro and Greece for both Dalmatian and great white pelicans.

Types of ANS referred to herein

Constructing artificial mounds of dredged material surrounded by ditches to act as islands; Lake Kerkini, Greece. © Theodoros Naziridis

Dalmatian pelicans nesting on a pontoon (floating pier) at Lake Kerkini, Greece. © Theodoros Naziridis

Constructing four wooden floating rafts, Lake Skadar, Montenegro.© Andrej Vizi

Fastening reed bundles onto floating rafts, which were initially used by pelicans for roosting and subsequently for nesting, 2007, Lake Sinoie, Romania. © Cristian Mititelu-Raileanu

Three joined 3 x 4m floating rafts after temporary use by pelicans; Lake Mikri Prespa, Greece. © Giorgos Catsadorakis / SPP


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d. Fixed wooden platforms restingon the ground Such platforms are made of joined wooden planks that are attached to a wooden frame but the whole structure is placed directly on the ground,

c. Elevated platforms supported by scaffoldsFixed elevated platforms have also been built in areas with high water level fluctuations, in order to cope with flooding or lack of proper nest-ing grounds. They have also been employed to prevent predators (wild boars, jackals, etc.) from reaching eggs and chicks. Poles, which support the platform, are driven into the ground and are made from either wood or metal. The platform itself is usually made of wooden planks and is covered wholly or partly with nesting material, mostly cut reed stems or other aquatic or salt-marsh plants already used by pelicans in natural nests. They have been used for Dalmatian pelicans in Turkey, Albania, Bulgaria and Greece. They have also been placed for use by spot-billed pelicans in India.

Raised wooden platform with pelican nests on top and underneath, Lake Kerkini. © Theodoros Naziridis

Metal scaffolding supporting raised platforms with pelican nests, Lake Manyas, Turkey. © Orhan Gül

Fixed wooden platform constructed to increase and raise the surface area available to pelicans for nesting, 2008, Ceaplace Island, Lake Sinoie, Romania. © Cristian Mititelu-Raileanu


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usually after some kind of levelling so that it lies horizontally. This was used in the Danube Delta, Romania, to extend the surface area of a nesting island and at the same time increase the height above water. They were supplied with a thick layer (40-70 cm) of cut reeds or other aquatic or salt-marsh plant stems to be used as nesting material by the birds.

The fixed platform offered more space and this allowed for an increase in the number of breeding pairs over a few consecutive breeding seasons, Ceaplace Island, Romania. © Dan Bandacu

e. Artificial trampling of reed tussocksThis is not a typical “structure” but is a kind of management intervention that modifies naturally occurring reed tussocks to simulate natural reed rhizome islands trampled by the birds and used as nesting sites. This process occurs naturally in winter when a thick and heavy snow layer cov-ers the reed-tufts and squashes them more or

less flat; the birds may then use them as nesting substrates the following spring. This method was successfully used at Mikri Prespa Lake, Greece in those years when it was suspected that the birds suffered from a shortage of natural nesting islands (1987-1990), and also successfully for a long time in Srebarna, Bulgaria.


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1. Volga Delta, Astrakhan, Russian FederationIn the early 1960s nesting sites of Dalmatian pelican in the lower delta had deteriorated due to strong winds raising water levels and nests being flooded. Both floating rafts and fixed platforms were provided. Floating rafts, ca 15 m2 in area, made of wood poles and reed stems, were placed at protected sites within openings in the reed-beds. They lasted for one season and then were waterlogged and partially submerged. Frames of wooden poles and reed mats supported by poles driven into the ground and lying 50-70 cm above water were first made in 1962. Ten to 32 pairs of Dalmatian pelican and several great cormorants used them successfully for four years (Bondarev 1976, Vinogradov et al. 1982).

2. Mikri Prespa Lake,Western Macedonia, GreeceCut reed stems were transported to natural islands to provide easily accessible nest material (1987). Floating rafts of various sizes (3x4 m to 10x4 m), made of wooden frames on which a thick layer of reed stems was fastened, were provided either directly adjacent to natural nesting islands or separately, to provide nesting sites in years of drought or flood when there was a shortage of natural islands. Rafts were used two out of three

years with varying breeding success. Artificial trampling of small, dense reed stands was also carried out for three years to provide further nesting “platforms” to pelicans and many of them were used successfully by the birds for nesting (Crivelli 1996 and Crivelli, A.J. & G. Catsadorakis, unpublished data).

3. Amvrakikos Lagoons, Epirus, GreeceIn 2001 three artificial islets were made with dredged sediments, to be used as a nesting ground for Dalmatian pelicans as part of the LIFE 99 NAT/GR/006475 project “Conservation Man-agement of Amvrakikos Wetlands”. The island was only used for roosting and resting by various

Management efforts with ANS / History and lessons learnt

waterbirds including pelicans. (http://ec.europa.eu/environment/life/proj-ect/Projects/index.cfm?fuseaction=search.dspPage&n_proj_id=403&docType=pdf, Anony-mous 2000)

4. Kerkini Reservoir,Central Macedonia, GreeceIn order to attract Dalmatian pelicans to nest at the site and cope with the 5-6m difference in water level between winter and spring, first an artificial island was constructed with dredged material, with an area of ca 80m2. A variety of waterbirds, including pelicans, used the island for roosting but no breeding took place in the

Adding reed bundles to the wooden floating platform, Lake Mikri Prespa, Greece. © Giorgos Catsadorakis / SPP

Two artificial islands, made of dredged material, after being used by pelicans; Lake Kerkini, Greece. © Theodoros Naziridis


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first two years. In April 1990 13 Dalmatian pelican nests were built and eggs were laid, which were all later abandoned, apparently due to human intrusion (Pyrovetsi 1997, Williams et al. 2013). In March 1988 two floating rafts were built and placed in suitable areas. They were ca 20m2 in area, and composed of a combination of a metal frame, two wooden poles and floating drums underneath, while they were also covered with a synthetic mat, itself covered with soil and debris on top. Dalmatian pelicans did not colonise the rafts. They were extensively used as resting sites by a variety of waterbirds instead, and common terns (Sterna hirundo) nested on the rafts success-fully in both years. An elevated wooden platform was built in 2002 and efforts to attract Dalmatian pelicans to nest at the site were re-launched in 2003. Dalmatian

pelicans nested successfully on it and also in sub-sequent years. It was small (110 m2) and suffered some damage so it was substituted with a larger one (180m2) in 2009 which was also very success-ful and accommodated higher numbers of nest-ers. A floating raft made of pieces of styrofoam covered with concrete floating material used for docks was also placed in 2014 and used success-fully by Dalmatian pelicans, and an artificial island of dredged material was constructed between the two existing platforms in winter 2015 (Th. Naziridis, KNPMB, in litt.)

5. Lake Manyas / Kuscenneti National Park, TurkeyThe destruction of natural islands forced Dalma-tian pelicans to nest in trees, unsuccessfully. In

1965 wooden platforms were built in trees and Dalmatian pelicans bred successfully on these for years. They needed lots of maintenance and were also vulnerable to strong winds. Pelican numbers initially rose and then declined. In 2003 and 2006 the national park authority built and placed 28 elevated wooden platforms on steel scaffolds. They are still used extensively and successfully by Dalmatian pelicans and nesting numbers have increased steadily since then (Onmuş et al. 2011)

6. Lake Srebarna, Lower Danube, Bulgaria This breeding colony of Dalmatian pelicans is a century old. Its problems started after the Second World War with the drainage of a great part of the huge wetland complex Kalarash-Silistra and espe-cially with negative changes in the water regime, advancing succession, an increasing number of

Dalmatian pelicans nesting on a raised wooden platform, Lake Kerkini, Greece. © Theodoros Naziridis

Raised wooden platforms among trees, Lake Manyas, Turkey.© Alain J. Crivelli

Raised metal platforms, Lake Manyas, Turkey. © Orhan Gül


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wild boars and the appearance of jackals in North Bulgaria after the 1980s. The building of artificial platforms for Dalmatian pelicans in Srebarna started in 1988 with the building of a floating raft and has continued suc-cessfully to date (Crivelli et al. 1991; Simeonov 2011, Michev & Kamburova 2012). The first fence to keep out predators and to attract new pairs was built in 1990. In 1998 an elevated platform (2 m above ground) was built by Foundation Le Balkan-Bulgaria, with the financial support of Swarovski Optik. In 1999 a second elevated platform was built as well as artificial floating platforms (rafts), while in 2010 a third pile plat-form was built. Mowed reed stems were piled on a surface of 600 m2 to raise the level of the nests in order for them not to be affected by high water

levels. They were all successful and they helped a lot in raising the number of breeding pairs at this site (Simeonov 2011).

7. Lake Skadar, MontenegroMajor threats to the small breeding colony of Dalmatian pelicans at Lake Skadar (Montenegro) were the frequent flooding of nesting islands by quickly rising water levels in spring (naturally) and human disturbance by fishermen and tourists (Vizi 1975, Saveljic et al. 2004). Two wooden floating rafts (3 x 4 m) were provided in 2004 but soon disappeared (D. Saveljic-CZIP 2012, in litt.) Eleven 2 x 3 m wooden floating rafts (with a frame of wooden beams, polystyrene board, two plank layers, above and below, and a layer of reed stems for nesting material) were placed in 2010. A great

flood destroyed most of these. In 2011, Dalma-tian pelicans used some of the remaining rafts but again floods forced an end to the breeding season. In autumn 2013, four 3.5 x 4 m rafts were placed close to the natural island and an additional one

Raised wooden platforms and floating rafts occupied by nesting pelicans, Lake Srebarna, Bulgaria. © Ivan Yantsev

Wooden floating rafts with a soil layer prior to being dragged into place, Lake Skadar, Montenegro. © Nela Vešović Dubak

Floating raft with nests and a solar-powered camera, Lake Skadar,Montenegro. © Andrej Vizi


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in 2014. In subsequent years Dalmatian pelicans nested successfully both on the natural sites and/or on rafts with similar breeding success. The rafts suffered some damage from sinking and weather-ing. (A. Vizi - MMNH, in litt.).

8. Karavasta Lagoon, AlbaniaDalmatian pelicans nest on a natural nesting island which suffered from erosion and flooding in high waters, and the placement of an ANS was thus judged necessary. An elevated platform was first built in December 2014 and enlarged in November 2015. Surfaces were 32 and 64 m2. The upper surface was 1.2 m above water and was

made of wooden planks whilst Salicornia stems were provided to be used as nesting material. It was placed ca 150 m away from the natural nest-ing island. To date (2016) it has not been used by Dalmatian pelicans (Taulant Bino, in litt.).

9. Danube Delta and lagoons, Romania At the end of the 1990s, small floating platforms were set up in Hrecisca Buhaiova (S. Bugariu, SOR, in litt.). In 2004, a small project for prevent-ing the further erosion of the island of Ceaplace (S. Bugariu, SOR, in litt.) was also implemented. As part of the LIFE05 NAT/RO/000169 project “Saving Pelecanus crispus in Danube Delta” a few

Raised wooden platform equipped with access ramp and provided with nesting material, Karavasta lagoon, Albania. © Taulant Bino

Wooden posts driven into the lakebed to support an underwater fence of woven willow branches, protecting Ceaplace Island from the erosive action of waves and water currents, Lake Sinoie, Romania. © Cristian Mititelu-Raileanu

Aerial photo of the fixed wooden platform constructed on Ceaplace Island, Romania, 2008. © Sebastian Bugariu


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artificial floating rafts were set up close to islands in the Sinoie lagoon, and an underwater wooden fence was constructed to prevent erosion through tempering the action of water currents. On the island of Ceaplace a fixed platform (320 m2) was constructed, aimed at increasing the available nesting area, and on the Prundul cu Pasari Islands two floating rafts were built and an underwater fence was constructed to limit erosion. In total eight floating rafts of 320 m2 total surface were constructed and placed on site. The total size of the nesting population was raised by more than 25% (Fantana et al. 2009).

10. Evros Delta, Evros Delta National Park,Thrace, GreeceDalmatian pelicans nested in the Evros / Meriç Delta until the 1960s. In winter 2012 an effort was started to attract them to nest in the delta area again in Greece. At first a small area was cleared of salt marsh vegetation on an island in a protected lagoon that was considered suitable for nesting, and where pelicans had often been observed to roost. In spring 2013 this area was flooded by high waters and an elevated platform was therefore built the following November at the same spot. The platform was made of wooden poles driven into the ground supporting a platform of planks, which measured 5 x 5 m and was 1.2 m above water. It was also provided with dry salt-marsh

plants to be used as nesting material, although these were twice blown away by strong winds. After securing nesting material against winds, the raft remained for two consecutive summers. It was only used occasionally by pelicans and other birds for resting (Birdwing and Evros Delta Na-tional Park Management Body, unpublished data).

A low raised wooden platform was used by Dalmatian pelicans as a roosting site only, August 2014, Evros Delta, Greece.© Panagiotis Ioannidis / Evros Delta National Park


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Biological impactsIn recent years ANS have become really popular and are increasingly considered as a means of enabling pelicans to nest or improving their nest-ing success. However, many times ANS have been either poorly constructed or sited, and sometimes they have been sought or deployed unnecessarily. Supervision by qualified managers is required to avoid improperly constructed or unnecessarily deployed ANS. It is emphasised that ANS should not be consid-ered as a remedy for the stochasticity brought about by natural variability, which is sometimes expressed for example as “good” years or “bad” years for an animal or a population. Poorly designed or maintained ANS can cause accidental bird mortality or nest failure.Floating rafts with inadequate buoyancy may be attractive nest sites to birds (De Sorbo et al. 2008), but can result in nest failure as materials become increasingly waterlogged over time. Several technical solutions have been tried to allow structures to follow the water level fluc-tuation without drifting a lot. Floating rafts are fastened to the bottom with anchors (weights) through cables, ropes or chains. Anchors are apt to drag (waves, underwater currents) and anchor cables or ropes often break. Improperly anchored

rafts (i.e., anchor lines too short or too long) can similarly result in nest failure, especially in cases of fluctuating water levels. The length of anchor cables, chains or ropes must be estimated care-fully to follow the anticipated increase of water level, and should also not be extremely long at the same time, because the whole structure will then move too much. An incident took place in Prespa, Greece, in the 1990s, when a case of ex-traordinary rise of water level was not anticipated by the raft-makers; the cables were too short and the raft was half-submerged until the cables could be replaced by longer ones. In 2014, at Kerkini Reservoir, Greece, the cables anchoring a floating

Potential negative biological and non – biological impacts of ANS

raft broke in a storm and the wind caused the raft to drift until it collided with a nearby elevated wooden platform and crushed the platform’s poles causing it to collapse. Fortunately no chick mortality was observed in this incident as chicks were already sufficiently grown. Another factor that is not frequently anticipated is how much the raft can sink with increased weight on it if more birds than expected use it at the same time.When elevated platforms are used, another fre-quent problem for chicks is that once they are in the water they cannot return back to the platform.

A floating wooden raft with nests started sinking after an extraordinary increase of water level in spring; 1991, Lake Mikri Prespa, Greece.© Giorgos Catsadorakis / SPP

A wooden platform that has collapsed after being knocked over by a floating pier (with nests) which became detached after a storm; Lake Kerkini, Greece.© Theodoros Naziridis


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Thus, either a suitable ramp should be construct-ed and/or an accessible alternative alighting place must be constructed very close to the platform, or under it.The importance of sheltering from weather has not been evaluated for pelican rafts and plat-forms. According to the direction and power of wind it might be more favourable for the birds to nest on the ground, even though there may be a high risk of flooding for the lower nests, than to suffer risks of hypothermia from strong winds on the elevated platform (if it is indeed the case that wind power is weaker on the ground than >1 m above it!). For example, Merrie (1996) and C. R. DeSorbo (pers. observ.) showed that unshel-tered rafts in diver territories were inappropriate

for nesting, as high exposure to wind and wave action could result in eggs getting wet or rolling out of nests, or non-use by divers.

Non-biological impactsNumerous important considerations about ANS are not fundamentally biological in nature, such as aesthetic issues, agency policies, cost, durability, maintenance requirements and the potential for depredation or other nuisance problems that some-times accompany an increasing bird population.Some people object to ANS because of their ob-trusiveness or artificiality. The type of structure, placement location, materials used, colour and shape are key aesthetic issues. Structures that are not easily seen are least likely to offend. Floating

rafts and earthen islands are often much less ob-trusive than elevated platforms. Aesthetic issues are important to many people, and the pressure to maintain visually pleasing environments will increase. With recognition and care, the most rea-sonable aesthetic concerns can be met (Ball 1990).ANS suffer from many kinds of degradation. Float-ing rafts, for example, have been constructed for pelicans in areas where water levels fluctuate. They have been highly accepted by pelicans, but practical problems have plagued many projects. For example in high-latitude / altitude wetlands, ice damage is severe unless rafts are removed each fall. Also, some animals may destroy unpro-tected flotation material. Furthermore, floating wooden structures will become waterlogged

A floating platform semi-sinking under the weight of hundreds of great white and a few Dalmatian pelicans on Lake Sinoie, Romania.© Sebastian Bugariu

A floating pier with nests and a wooden access ramp to enable chicks to climb back to nests, Lake Kerkini, Greece. © Theodoros Naziridis

Artificial island made of rocks and stones with pelican nests on top, Lake Kerkini, Greece. © O. Alexandrou / SPP


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and will sink unless flotation materials have been added. Wooden logs in the frames have been re-placed by PVC plastic tubes of a large diameter, with their open ends capped to act both as a sup-porting frame and flotation material. Nest mate-rial must be wired to the surface of the platform, or kept in position by additional thin wooden poles, to prevent it from being blown off. The latter has happened in many cases.

The need for continuing maintenance is probably the most commonly overlooked disadvantage of ANS. ANS programmes probably fail more because of inadequate maintenance than for all other reasons combined. Consequently, a programme should not be initiated unless the necessary maintenance can be continued for at least 10 years (Ball 1990).

Two raised wooden platforms in the landscape of Lake Kerkini, Greece. © Theodoros Naziridis


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The underlying basic assumption is that the considered species is threatened locally, regionally or globally and it is in need of support in order to secure and enhance its existing populations.

STEP 1A: Identify as accurately as possible the issue to be tackled by introducing an ANS

There are four main needs that may be addressed by an ANS:

A1. Need to accommodate an increasing or surplus populationThis means that there are strong indications of, or hard evidence for, a com-bination of the following events: many floaters (adult birds which are able to breed but not actually breeding) occur seeking opportunities to nest; existing natural nesting sites are saturated; the particular population is very small and/or at the brink of extinction, and needs support to overcome a certain safety

threshold. Answers to the above critical questions must rely on the results and conclusions of well-designed scientific research.

A2. Need to enhance a very low breeding success The reasons for which a markedly low breeding success is repeatedly ob-served in a particular population, i.e. eggs and/or chicks suffer from high mortality/loss/abandonment, may be the following: existing nesting sites are of low quality (durability, nesting material availability, susceptibility to erosion, wave action, storms, etc); existing sites suffer from frequent floods or droughts (natural or anthropogenic) and there are no alternative sites available; floods destroy nests/eggs and droughts make colonies accessible to terrestrial predators by creating bridges to nearby land.

A3. Need to ensure that nesting sites are free of disturbance byhumans because natural ones suffer from heavy disturbanceThis may happen when natural nesting islands only occur in parts of the wetland which are heavily used by fishermen for fishing, tourists, boat traffic, poachers, anglers, etc. Thus the colonies suffer from high levels of disturbance which it is difficult to stop because it is impossible to divert these activities to somewhere else.

Protocol for evaluating the need for ANS

SEQUENCE 1Interventions at sites already used bypelicans for nesting


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A4. Need to ensure safe nesting sites in view of imminentnegative changes It is foreseen that existing nesting sites are being degraded at high rates from various causes and shortly there will not be suitable sites available. For example, hydrological changes may have taken place which render natural nesting sites susceptible to erosion and degradation at very high rates and it is anticipated that they will soon be destroyed and the birds will have to move to some other safer place to nest, but such sites are not available.

STEP 1B: Is intervention the right thing to do?There has been a long debate about the pros and the cons of intervening with hands-on management in comparison to “let alone” tactics under varying circumstances and conditions. This discussion has wide-ranging philosophi-cal dimensions and, beyond purely conservation matters, it also entails other matters (aesthetics, cost-benefit ratios, etc.), as many important consider-ations about whether to intervene or not are not fundamentally biological in nature (Ball 1990). The natural vs the artificial is also a long and big debate (Birnbacher 2006), as well as the whole issue of naturalness (Schnitzler et al.

2008). The “let alone” choices however, are not always directly compatible to conservation needs in the quickly changing habitats of the modern world under human pressure.

STEP 1C. Is intervention with an ANS the right thing to do?Alternative kinds of interventions should also not be overlooked or underes-timated, and deserve careful consideration: Managing apparently unsuitable natural sites to simulate nesting sites is an example of this approach. Tram-pling of naturally occurring clumps of reeds in winter to facilitate subsequent use by pelicans has been proved very successful in Lake Prespa National Park, Greece (Crivelli A. J. and G. Catsadorakis, unpublished data). Another alterna-tive kind of intervention would be to try to influence, and eventually modify, hydrological attributes in order to amplify the rise and fall of the water level and thus critically improve the condition of pelican nesting islands. A third example of an alternative intervention that should be examined as a sub-stitute to ANS would be to use management measures to consolidate sites and islands susceptible to erosion with a variety of existing techniques, as for example has been used in the Danube Delta in Romania (Fantana et al. 2009).


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SEQUENCE 2: Interventons at sites where there are no nestng pelicans (or which had

been used in the recent or distant past)

STEP 1D: In cases where a decision to intervene with an ANShas been arrived at

A number of crucial questions have to be answered after this decision has initially been reached: ▶ What kind of ANS? (Are islands preferable to elevated platforms or floating rafts?)▶ How large would each ANS be? How many pieces of it will be placed? For how long they will be in place? Where exactly are they to be placed within the wetland?▶ Will it be possible to carry out monitoring of the ANS and for how long?▶ Which parameters are to be monitored and for how long?▶ Is the cost for maintenance and guarding affordable in the long run?▶ Is there an issue of a trade-off, such as between conservation needs and naturalness of the landscape for example?▶ Have potentially negative impacts to other wildlife species or values been identified? There are often incompatibilities between various conservation targets.▶ Will it be feasible to remove the ANS after a certain period if it has become unnecessary or undesired? ▶ Have all safety problems for the target species or other wildlife been taken into consideration beforehand? ▶ Final, but crucially: what is the target number of breeding pairs sought? This is closely connected to the carrying capacity of the ecosystem.


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STEP 1AIdentify as accurately as possible the issue to be tackledby introducing an ANS Before any other consideration, a feasibility study should be undertaken to answer the following question: why do pelicans not use this wetland, or have not bred in this wetland up to now, or don’t breed in this wetland anymore (for those wetlands where they were breeding formerly)? The study should adopt an ecosystem approach. If the study has a clear conclusion, then one can start to answer the steps below. If the conclusion is not clear, the procedure should stop and the studies needed in order to clarify the answer should be undertaken. Again, the underlying basic assumption that should be kept in mind is that this particular species is threatened in this part of the world, or globally, and it is in dire need of support in order to secure and enhance its existing populations.The essence of the challenge is whether the position that the creation of a new nest-ing colony will be beneficial for the overall conservation status of the species in the region can be convincingly defended. Adopting the logic of an integrated ecosystem approach, decision-makers should ask themselves whether they have any idea of the optimal carrying capacity of the site, in other words, for this particular site: ‘How many pelicans are enough?’In fact, the case for ANS should be examined only in those situations where a site fulfils all other requirements for the nesting of these species but does not have available natural nesting sites.Thus, in cases where there is no nesting colony on-site and managers aspire to create one, i.e. to attract birds to nest by providing them with ANS, then the issues to be dealt with are more numerous than for cases where pelicans already nest:

STEP 2.AAre there clear indications that adequate numbers of individuals of the species (including adults) are present in this particular wetland all year round, or for a few months during the breeding season?If not, stop processIf yes, proceed to Step 2.B

STEP 2.BAre all the requirements for ensuring the long-term breeding of the species in the specific wetland fulfilled? (For requirements see Box 1 above)If not, stop processIf yes, proceed to Step 2.C

STEP 2.CIs the creation of a pelican colony possible given the existing legal and institutional constraints?If not, stop processIf yes, proceed to Step 2.D

STEP 2.DIn cases where there are local human societies sharing the resources of the wetlands, is there a minimum social acceptance by stakeholders of the decided management measures for the creation of this new colony? If not, stop processIf yes, proceed to Step 2.E

STEP 2.EIs the adoption of the ANS strategy desirable and accepted from a philosophical and aesthetic point of view (naturalness vs artificiality, alteration to the natural landscape, etc)If not, stop processIf yes, proceed to Steps 1B, 1C and 1D.

SEQUENCE 2Interventions at sites wherethere are no nesting pelicans(or which had been usedin the recent or distant past)


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As for many other issues in ecology and conservation science, the magic words regarding the whole issue of ANS are “trade-off” and “integrated ecosystem approach”. Both are burdened with a complex interlinkage of reiterating ethical, practical and scientific dilemmas and decisions that have to be made. ANS are not equal in ecological value to natural nest-site alternatives, and do not fully cope with ecosystemic problems for pelican populations, such as the rapid degradation of nesting habitat or artificially fluctuating water levels. It is well known that although it is better to leave nature decide on questions such as which, what, when and how much, and for how long, the diverse pressure on natural ecosystems from humans continuously creates

Reflection and special considerations

disturbances and alterations. These alterations, combined with the -purely- ethical decision of human societies not to allow any species of organism to violently disappear from the planet, have created the need for humans to intervene in order to restore, to rehabilitate, etc. Duffy (1994) has written something about island ecosystems that also holds true for wetlands too: “...we cannot really restore island ecosystems, yet we cannot leave them alone”. However, the questions: “Under which circumstances can the active, hands-on intervention of man in order to manage the populations of a wild animal be justified?”, and “Which is the threshold beyond which this intervention is no longer justified?” have not been answered in a fit-for-all manner.


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1. ANS can indeed improve the reproductive success of nesting birds.

2. ANS are not equal in ecological value to natural nest sites and do not fully solve problems for pelican populations relating to the capacities of the ecosystems they belong to.

3. ANS in natural wetlands can be considered only after >5 years of monitor-ing (nesting numbers, nest distribution, presence of non-nesters, quality of nesting islands, breeding success, causes of failure) has indicated a consistent nest-failure history due to predation, water-level fluctuation, erosion, preda-tion, or disturbance, and other preventive approaches, such as education, pub-lic awareness, habitat protection, water-level stabilisation and limiting access by guarding and cordoning off nest areas, have failed (DeSorbo et al. 2008).

4. Make sure all available evidence is compiled in order to be able to clearly answer the question: “Why do we wish to build and place an ANS in our wet-land?” In collaboration with, amongst others, at least one wetlands expert and

Key messages and recommendations

one pelican expert, decide if there are one or more reasons from those de-scribed above which make the building and placement of an ANS necessary.

5. Do not underestimate the importance of the conflict of values. A typical example is the impact of ANS upon landscape aesthetics.

6. With the help of other managers who have perhaps already applied similar measures, carefully prepare a budget for the endeavour.

7. With the help of one or more social scientists, carefully estimate how the local society perceives the application of ANS, i.e. the degree of social ac-ceptance.

8. Try to evaluate as carefully as possible, and with all possible available sci-entific and research tools, what the increase in nesting pelicans will mean for the ecosystem in terms of the impact on food resources, inflow of nutrients to the wetland through droppings, competition with other species, etc.


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9. Try also to assess in the most robust way possible what would be the impact of the increase in nesting pelicans on the local economy.

10. Consider the potential negative impacts that the increase/creation of a pelican population may have on other rare and valuable elements of the ecosystem.

11. Whilst designing the ANS remember that nest failure can also result from improperly constructed or deployed rafts.

12. Make sure a well-designed monitoring system is in place for the next 10 years.

13. Make sure that the management entity responsible for managing the effort will be there to ensure the continuation of the maintenance (Ball 1990) and monitoring for at least 10 years.

14. Often the first management intervention brings a need for an endless series of interventions; so, last but certainly not least, try to define the upper limit of the endeavour, i.e. when you will say “this number is enough”, and incorporate this maximum number in your plans in a clear way.

15. Adherence to the protocols presented in this document will aid in en-suring that ANS are constructed and deployed appropriately to achieve the maximum benefit for pelican populations.

16. All decisions should be taken within the context of an integrated eco-system approach.


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In wetlands where pelicans occur for all or part of the year and managers wish to explore the possibility / feasibility of attracting them to establish a nesting colony in these wetlands:

▶ Make sure that guarding of a potential future colony, to keep it free of human disturbance, is completely guaranteed.

▶ Make sure that the local society is (at least) tolerant of this decision

▶ Make sure that there is sufficient, and available, prey to be able to sustain at least 50 pairs of pelicans for half a year.

▶ Make sure that the conceived ANS can be placed in an area whose management can be fully controlled by the co-operating managers, preferably within an officially protected area.

Use of artificial platforms by nesting pelicans after they were placed close to Ceaplace Island in 2007, Lake Sinoie, Romania. © Sebastian Bugariu


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Artificial Nesting Structures for Eurasian pelicans · of pelicans, mainly due to successful conservation measures in some key places (e.g. Prespa and Amvrakikos, Greece), has led