Effects of human disturbance on nest placement of the Woodpigeon in Morocco

Hanane, S. 2014. Effects of human disturbance on nest placement of the woodpigeon (Columba palumbus): a case study from the Middle Atlas, Morocco. Integrative Zoology 9: 349–359.  doi: 10.1111/1749-4877.12078

Abstract:

The Woodpigeon (Columba palumbus) is a common and widespread bird in Morocco (North Africa). I examined, over two years (2010 and 2011), the breeding density and nest placement of this game species in relation to nest-site habitat and degree of human disturbance. The study area was in the Middle Atlas Tighboula mountain forest, Morocco, in a disturbed and an undisturbed site. Using data collected in the two study sites, I aimed to identify the factors influencing the placement of nests within Holm oak trees (Quercus rotundifolia) and their densities. I found that habitat structures, influenced by grazing disturbance, have affected nesting density and location of nests of this species. Woodpigeons place their nests in a higher position (3.42 ± 0.19 m) when disturbance intensity is high and lower (1.68 ± 0.1 m) when it is low and showed higher nesting density in less disturbed zone (3.1 ± 0.4 nests/ha) than in high disturbed one (1.4 ± 0.2 nests/ha). Grazing disturbance could pose a threat to population persistence at a broader scale and could potentially contribute to reduce the abundance of this species by altering the composition and the structure of the forest nesting habitat. Further multi-scale studies are needed to assess the effects of different levels of grazing disturbance on Woodpigeon nest density and placement and to enhance our knowledge on breeding behaviour of this game species under variable environments.

Woodpigeon (Columba palumbus) on nest

Woodpigeon Columba palumbus. (Photo by flickr member gynti_46, licence CC-by-nc-sa)

Subalpine Warbler split into three different species

In a new paper, prominent ornithologist Lars Svensson summarised the recent research on the taxonomy of the Subalpine Warbler (Sylvia cantillans) and recommended the split of the complex into three separate species:

– Western Subalpine Warbler (Sylvia inornata), with two subspecies: inornata and iberiae (a new subspecies described in the paper for the birds breeding in the Iberian Peninsula, southern France and extreme north-west Italy),

– Eastern Subalpine Warbler (Sylvia cantillans), with two subspecies: cantillans and albistriata, and

– Moltoni’s Warbler (Sylvia subalpina, monotypic).

The taxon cantillans, historically associated with western birds (i.e. from Iberia), is now one of the subspecies of the Eastern Subalpine Warbler because the type specimen of cantillans is a bird collected from Italy and found out to belong to the Eastern Subalpine Warbler. And that’s why Lars Svensson created a new name for the Iberian birds (Sylvia inornata iberiae).

North African birds:

With this taxonomic revision, Subalpine Warbler breeding in north-west Africa which were known as Sylvia cantillans inornata becomes the nominate subspecies of the Western Subalpine Warbler Sylvia inornata inornata.

Svensson, L. 2013. A taxonomic revision of the Subalpine Warbler Sylvia cantillansBulletin of the British Ornithologists’ Club 133: 240-248.

This is based on a much detailed blog-post published at MaghrebOrnitho.

Map of the breeding ranges of all five taxa of the subalpine warbler complex.
Map of the breeding ranges of all five taxa of the Subalpine Warbler complex. The grey zone in the north of Italy is of the intergradation between subalpina and cantillans. The points are locations with proven cases of sympatry. The map constructed by Lars Svensson from Shirihai et al (2001), Brambilla et al (2006), and comments from M. Ullman (© Lars Svensson).
Moltoni’s Warbler (Sylvia subalpine)
Moltoni’s Warbler (Sylvia subalpina), Mallorca, Spain (© José Luis Copete)
 Western Subalpine Warbler (Sylvia inornata iberiae)
Western Subalpine Warbler (Sylvia inornata iberiae), Portugal. (Rodrigo Saldanha de Almeida on flickr, licence: CC-by)

Annual cycle and migration strategies of Great Reed Warbler as revealed by a geolocator study

Lemke HW, Tarka M, Klaassen RHG, Åkesson M, Bensch S, Hasselquist D & Hansson.B. (2013) Annual Cycle and Migration Strategies of a Trans-Saharan Migratory Songbird: A Geolocator Study in the Great Reed Warbler. PLoS ONE 8(10): e79209. doi: 10.1371/journal.pone.0079209

Abstract:

Recent technological advancements now allow us to obtain geographical position data for a wide range of animal movements. Here we used light-level geolocators to study the annual migration cycle in great reed warblers (Acrocephalus arundinaceus), a passerine bird breeding in Eurasia and wintering in sub-Saharan Africa. We were specifically interested in seasonal strategies in routes and schedules of migration. We found that the great reed warblers (all males, no females were included) migrated from the Swedish breeding site in early August. After spending up to three weeks at scattered stopover sites in central to south-eastern Europe, they resumed migration and crossed the Mediterranean Sea and Sahara Desert without lengthy stopovers. They then spread out over a large overwintering area and each bird utilised two (or even three) main wintering sites that were spatially separated by a distinct mid-winter movement. Spring migration initiation date differed widely between individuals (1-27 April). Several males took a more westerly route over the Sahara in spring than in autumn, and in general there were fewer long-distance travels and more frequent shorter stopovers, including one in northern Africa, in spring. The shorter stopovers made spring migration on average faster than autumn migration. There was a strong correlation between the spring departure dates from wintering sites and the arrival dates at the breeding ground. All males had a high migration speed in spring despite large variation in departure dates, indicating a time-minimization strategy to achieve an early arrival at the breeding site; the latter being decisive for high reproductive success in great reed warblers. Our results have important implications for the understanding of long-distance migrants’ ability to predict conditions at distant breeding sites and adapt to rapid environmental change.

Great Reed Warbler Acrocephalus arundinaceus

Great Reed Warbler Acrocephalus arundinaceus (Vitaliy Khustochka on flickr, licence CC-by-nc)

Spatial patterns in North Africa:

The majority of males crossed the Mediterranean Sea and Sahara Desert without stopovers in a flight that exceeded 24 hours in duration, in a geographical window spanning from Tunisia/Algeria in the west to Libya in the east.

In spring, after crossing the Sahara desert, all great reed warbler males stopped just south of the Mediterranean Sea in northeast Algeria and western Tunisia. From the stopover in North Africa most males took off in a north-easterly direction towards Italy and Balkan, which allowed these birds to pass east of the Alps and to return more or less on the same track through Europe as taken in autumn.

A completely unexpected result was that all males spent 1-2 weeks at the end of April or beginning of May in a rather restricted area in north-eastern Algeria and western Tunisia, independent of where along the west–east axis of sub-Saharan Africa they had spent their second part of the winter.

Inferred migration routes, mid-winter movements and stopover sites from geolocator data of male great reed warblers

Inferred migration routes, mid-winter movements and stopover sites from geolocator data of male great reed warblers.
(A) Migration routes and mid-winter movements (blue: autumn; green: spring; yellow: mid-winter).
(B) Stopover sites (stays for more than 36-hours) in autumn (blue) and spring (green), and wintering sites (yellow). Breeding site is indicated (star). Data are for 8 males in autumn and winter, and 6 males in spring. doi:10.1371/journal.pone.0079209.g001

Short‐distance migration of Wrynecks from Central European populations

Wijk, R. E., Schaub, M., Tolkmitt, D., Becker, D. & Hahn, S. 2013. Short-distance migration of Wrynecks Jynx torquilla from Central European populations. Ibis 155 (4): 886–890.  doi: 10.1111/ibi.12083
PDF in ResearchGate.net

Abstract:

European Wrynecks Jynx torquilla torquilla have generally been considered to be long-distance Palaearctic–African migrants that spend the non-breeding season in Sahelian Africa, where they have been reported regularly. Results from tracking individual birds showed that Wrynecks from two Central European populations migrated only relatively short distances to the Iberian Peninsula and northwestern Africa (c. 1500 km and 3000 km, respectively), compared with a minimum distance of about 4500 km to Sahelian Africa. Additionally, differences in wing lengths of populations from Central and Northern Europe support the idea of leap-frog migration, populations from Northern Europe being long-distance migrants with a non-breeding distribution in Sahelian Africa.

Wryneck (Jynx torquilla)

Wryneck Jynx torquilla (Åsa Berndtss on flickr, license: CC-by)

First banding scheme of Glossy Ibis (Plegadis falcinellus) in Algeria

Samraoui, B., Boucheker, A., Nedjah, R., Youcefi, A. & Samraoui F. (2012). First banding scheme of Glossy Ibis Plegadis falcinellus in Algeria. Aves Ichnusae 10: 30-37.
PDF in ResearchGate.net.

Abstract:

Over the last decade, the Glossy Ibis has staged a come-back in Algeria after an absence lasting almost a century. The breeding was recorded in the year 2002 and in the period 2003-2008 the breeding population has been monitored at four sites across the wetland complex of Numidia, north-east Algeria. In order to increase our knowledge of the causes underlying fluctuations in the dynamics of local colonies, a banding scheme of Glossy Ibis chicks was started in 2008, for the first time in North Africa. A total of 72 chicks of a c.100 breeding pairs estimated in three distinct colonies were banded.

Ringing Glossy Ibis (Plegadis falcinellus) in Algeria.

Ringing Glossy Ibis (Plegadis falcinellus) in Algeria. (B. Samraoui in Photo-Guide to Colour-Ringed Birds)

 

Algerian bands/rings starts with letter J.

Number of coloured Darvic bands, composition and range of codes fitted to Glossy Ibis Plegadis falcinellus chicks across Numidia, northeast Algeria in 2008.

Number of coloured Darvic bands, composition and range of codes fitted to Glossy Ibis Plegadis falcinellus chicks across Numidia, northeast Algeria in 2008 (Samraoui et al. 2012).

First evidence of a 200-day non-stop flight in a bird

Liechti, F., Witvliet, W., Weber, R., & Bächler, E. (2013). First evidence of a 200-day non-stop flight in a bird. Nature Communications 4:2554. doi: 10.1038/ncomms3554

Abstract:

Being airborne is considered to be energetically more costly as compared with being on the ground or in water. Birds migrating or foraging while airborne are thought to spend some time resting on the ground or water to recover from these energetically demanding activities. However, for several decades ornithologists have claimed that some swifts may stay airborne for almost their whole lifetime. Here we present the first unequivocal evidence that an individual bird of the Alpine swift (Tachymarptis melba) can stay airborne for migration, foraging and roosting over a period of more than 6 months. To date, such long-lasting locomotive activities had been reported only for animals living in the sea. Even for an aerodynamically optimized bird, like the Alpine swift, flying requires a considerable amount of energy for continuous locomotive control. Our data imply that all vital physiological processes, including sleep, can be perpetuated during flight.

Alpine Swift (Tachymarptis melba)

Alpine Swift (Tachymarptis melba) (Ferran Pestaña on flichr, license: CC-by-sa)

Communiqués de presse de la Station ornithologique suisse (08.10.2013) :

Champion du monde en vol d‘endurance

Nouveau record : le martinet à ventre blanc six mois non-stop dans les airs

Maestro avéré du vol non-stop, le martinet à ventre blanc passe la moitié de l’année dans les airs. L’agile volatile doit son titre à une technique des plus modernes, qui a permis aux chercheurs de la Station ornithologique suisse de prouver ce dont on se doutait depuis longtemps.

Sempach – Les oiseaux aussi se voient obligés de poser « patte » à terre de temps en temps pour se nourrir ou tout simplement se reposer. Les martinets font pourtant exception. Parfaitement adaptés à la vie dans les airs, ces acrobates aériens se nourrissent d’insectes volants qu’ils prélèvent au passage. On se doutait bien qu’ils ne se posaient même pas pour dormir : l’observation au radar de martinets noirs tournant très haut dans le ciel nocturne avait déjà mis la puce à l’oreille des ornithologues.

Une performance désormais confirmée par les chercheurs de la Station ornithologique suisse de Sempach, qui ont prouvé que leur cousin le martinet à ventre blanc est capable de voler en continu pendant plus de six mois. En 2011, les chercheurs ont équipé des martinets à ventre blanc de géolocalisateurs après leur nidification. Développées en collaboration avec la Haute école spécialisée bernoise de Burgdorf, ces petites merveilles technologiques d’environ 1 g permettent de mesurer et d’enregistrer la luminosité de l’endroit où se trouve l’oiseau pendant une année. La longueur du jour, et ainsi la position géographique de l’oiseau, sont ensuite calculées à partir de ces données. Spécialité de cette étude, ces appareils étaient munis d’un capteur d’activité enregistrant et différenciant les phases de battement d’ailes de celles de repos.

Ainsi frétés d’un géolocalisateur, les martinets à ventre blancs prirent la direction de leurs quartiers d’hiver. Après y avoir passé la saison froide, ils réintégrèrent leurs sites de nidification suisses, où les ornithologues les délestèrent de leur petit sac à dos. « L’analyse des données de trois martinets a montré que ces oiseaux passent l’hiver surtout en Afrique de l’Ouest», explique Felix Liechti, responsable du département « migration des oiseaux » à la Station ornithologique et premier auteur de l’étude. « Révolutionnaire est la découverte que ces martinets volent en continu pendant leur migration et dans leur zone d’hivernage »

Ces résultats démontrent que les martinets à ventre blanc sont aussi capables de maintenir toutes leurs fonctions corporelles vitales pendant un vol d’endurance. Ils n’ont pas besoin du même type de sommeil que nous autres humains.

Migration routes and non-breeding range of three Alpine swifts breeding in Switzerland

Les martinets à ventre blancs suisses hivernent en Afrique de l’Ouest. Chaque couleur représente un individu différent. Les surfaces colorées indiquent les zones où les oiseaux ont séjourné un certain temps.
(Foto: © Station ornithologique suisse)

Geolocator (Felix Liechti)

Les géolocalisateurs ont été miniaturisés en continue ces dernières années.
(Foto: © Felix Liechti, Station ornithologique suisse)

Black-necked Grebe: an expanding species in the Middle Atlas wetlands, Morocco

Cherkaoui, I., Bouajaja, A., Elbanak, A., Lahrouz, S. & Hanane 2014. The Black-necked Grebe (Podiceps nigricollis): an expanding species in the Middle Atlas wetlands, MoroccoWetlands Ecology and Management 22: 93-98. doi: 10.1007/s11273-013-9321-7
PDF in ResearchGate.net

Abstract:

The present study investigates the population trends of Black-necked Grebe Podiceps nigricollis (Podicipedidae: Podicidae) over 5 years (2009–2013) in three Middle Atlas wetlands (Aguelmam Afennourir, Dayet Aoua and Dayet Ifrah). Using generalized linear models with a Poisson distribution, we demonstrated that the number of Black-necked Grebe breeding pairs has varied significantly and positively over the 5 years and between the three study wetlands. The annual population growth rate of the three colonies was 0.48 (±0.01). This positive trend is consistent with the current Least Concern conservation status of the IUCN Red List. Further more detailed studies are, however, needed to improve our understanding on the mechanisms driving the population increase in this part of North Africa. This remains a prerequisite for proper population conservation and management.

Black-necked Grebe (Podiceps nigricollis)

Black-necked Grebe Podiceps nigricollis (Alan Vernon, flickr)