Hammouda, A., Hamza, F., Ayadi, T., Pearce-Duvet, J. & Selmi, S. (2016). Assortative mating for carotenoid colouration but not size in the Yellow-legged Gull Larus michahellis. Bird Study 63: 289–292. doi: 10.1080/00063657.2016.1185087 PDF
In conclusion, our results suggest that carotenoid-based colouration plays a more important role in mate choice than does body size in Mediterranean Yellow-legged Gulls. However, these results might have been impacted by the study’s small sample size. Moreover, our data are descriptive in nature and reveal nothing about potential underlying processes. We thus believe that additional studies involving larger data sets obtained from marked birds and field experiments are necessary to clarify mate choice mechanisms in this species.
Vidal-Mateo, J., Mellone, U., López-López, P., De La Puente, J., García-Ripollés, C., Bermejo, A. & Urios, V. (2016). Wind effects on the migration routes of trans-Saharan soaring raptors: geographical, seasonal, and interspecific variation. Current Zoology 62: 89–97. doi: 10.1093/cz/zow008 (Open Access)
Wind is among the most important environmental factors shaping birds’ migration patterns. Birds must deal with the displacement caused by crosswinds and their behavior can vary according to different factors such as flight mode, migratory season, experience, and distance to goal areas. Here we analyze the relationship between wind and migratory movements of three raptor species which migrate by soaring–gliding flight: Egyptian vulture Neophron percnopterus, booted eagle Aquila pennata, and short-toed snake eagle Circaetus gallicus. We analyzed daily migratory segments (i.e., the path joining consecutive roosting locations) using data recorded by GPS satellite telemetry. Daily movements of Egyptian vultures and booted eagles were significantly affected by tailwinds during both autumn and spring migrations. In contrast, daily movements of short-toed eagles were only significantly affected by tailwinds during autumn migration. The effect of crosswinds was significant in all cases. Interestingly, Egyptian vultures and booted eagles showed latitudinal differences in their behavior: both species compensated more frequently at the onset of autumn migration and, at the end of the season when reaching their wintering areas, the proportion of drift segments was higher. In contrast, there was a higher drift at the onset of spring migration and a higher compensation at the end. Our results highlight the effect of wind patterns on the migratory routes of soaring raptors, with different outcomes in relation to species, season, and latitude, ultimately shaping the loop migration patterns that current tracking techniques are showing to be widespread in many long distance migrants.
Halassi, I., Elafri, A., Belhamra, M. & Houhamdi, M. (2016). Répartition et abondance de l’Érismature à tête blanche Oxyura leucocephala dans les zones humides du nord-est algérien. Alauda 84: 25–34. PDF in ResearchGate
Status of the White-headed Duck Oxyura leucocephala in Northeast Algeria. The globally threatened White-headed Duck is one the most rare duck species in the Western Palearctic. Its distribution in Algeria is mainly restricted to the northeastern part of the country and the Hauts-Plateaux. In 2013 and 2014, 694 individuals were counted. The studied sites harboured distinct numbers in winter and in summer of the two years. The p-values (Kruskal Wallis test) were lower than 0.05. The Lake Tonga showed the highest numbers in winter and the Boussedra wetland in summer. The results indicated a stable occurrence in the studied areas without any difference between the two years. The PCA analysis showed a significant correlation between the distribution of this species and three following main factors: vegetation, surface area and water depth at the Boussedra wetland, Lake Tonga and Garaet Hadj-Taher. The lower occurrence in other parts of the studied areas, particularly on the Hauts-Plateaux, is mainly the consequence of drying out process and habitat degradation.
Menaa, M., Maazi, M. C., Telailia, S., Saheb, M., Boutabia, L., Chafrour, A. & Houhamdi, M. (2016). Richness and Habitat Relationships of Forest Birds in the Zeen Oak Woodland (Forest of Boumezrane, Souk-Ahras), Northeastern Algeria. Pakistan J. Zool. 48: 1059–1069. PDF in ResearchGate
Boumezrane’s forest is a significant center for biodiversity. Since last year the forest is facing destruction and degradation. Although the forest is recognized as an important area for avian diversity, it has never received ornithological attention. Many studies have been conducted on the relationship of birds with habitat features, however their associations are not completely understood. Hence we need information on the relationship between occurrence of birds and structural components of zeen oak habitats. We examined relative bird abundance by using the point count method and its relationship to environmental descriptors. A total of 68 visits of 39 bird species were recorded in the zeen oak stands. Avian species richness at each point count ranged between four and 14 species. The most dominant families in number of pairs are Paridae (121 pairs), Turdidae (115.5 pairs), Sylviidae (57.5 pairs), Picidae (55.5 pairs), and Fringillidae (43.5 pairs). They cater for more than 70% of the total abundance of the entire community. Using principal component analysis and canonical correspondence analysis methods, we determined that the size of trees with the height of shrub layer is an important criterion for differentiation of the avifauna of Boumezrane. The second criterion is the volume of tree stratum.
Vardanis, Y., Nilsson, J.-Å., Klaassen, R. H. G., Strandberg, R. & Alerstam, T. (2016). Consistency in long-distance bird migration: contrasting patterns in time and space for two raptors. Animal Behaviour 113: 177–187. doi: 10.1016/j.anbehav.2015.12.014 PDF in ResearGate.net
As the evolutionary responses to environmental change depend on selection acting on individual differences, disentangling within- and between-individual variation becomes imperative. In animal migration research, multiyear tracks are thus needed to estimate the individual consistency of phenotypic traits. Avian telemetry studies have recently provided the first evidence of individuality across space and time in animal migration. Here, we compare repeatability patterns of routes and timing between two migratory birds, the marsh harrier, Circus aeruginosus, and the osprey, Pandion haliaetus, as recorded by satellite tracking. We found interspecific contrasts with low repeatability in timing and duration and a high repeatability in routes for ospreys, but the reverse pattern for marsh harriers. This was mainly caused by (1) larger between-individual variation in routes for ospreys (broad-front migration) than for marsh harriers (corridor migration) and a higher degree of repeated use of the same stopover sites among ospreys, and (2) higher within-individual consistency of timing and duration among marsh harriers, while individual ospreys were more flexible. Our findings suggest that individuality in space and time is not a shared trait complex among migrants, but may show adaptive variation depending on the species’ life history and ecology.
Lindström, Å., Alerstam, T., Bahlenberg, P., Ekblom, R., Fox, J. W., Råghall, J., & Klaassen, R. H. G. (2016). The migration of the great snipe Gallinago media: intriguing variations on a grand theme. Journal of Avian Biology 47: 321–334. Free access (now)
The migration of the great snipe Gallinago media was previously poorly known. Three tracks in 2010 suggested a remarkable migratory behaviour including long and fast overland non-stop flights. Here we present the migration pattern of Swedish male great snipes, based on 19 individuals tracked by light-level geolocators in four different years. About half of the birds made stopover(s) in northern Europe in early autumn. They left the breeding area 15 d earlier than those which flew directly to sub-Sahara, suggesting two distinct autumn migration strategies. The autumn trans-Sahara flights were on average 5500 km long, lasted 64 h, and were flown at ground speeds of 25 m s−1 (90 km h−1). The arrival in the Sahel zone of west Africa coincided with the wet season there, and the birds stayed for on average three weeks. The birds arrived at their wintering grounds around the lower stretches of the Congo River in late September and stayed for seven months. In spring the great snipes made trans-Sahara flights of similar length and speed as in autumn, but the remaining migration through eastern Europe was notably slow. All birds returned to the breeding grounds within one week around mid-May. The annual cycle was characterized by relaxed temporal synchronization between individuals during the autumn–winter period, with maximum variation at the arrival in the wintering area. Synchronization increased in spring, with minimum time variation at arrival in the breeding area. This suggests that arrival date in the breeding area is under strong stabilizing selection, while there is room for more flexibility in autumn and arrival to the wintering area. The details of the fast non-stop flights remain to be elucidated, but the identification of the main stopover and wintering areas is important for future conservation work on this red-listed bird species.
Palacín, C., Martín, B., Onrubia, A. & Alonso, J. C. 2016. Assessing the extinction risk of the great bustard Otis tarda in Africa. Endang Species Res 30: 73–82. doi: 10.3354/esr00726 (Open Access)
We studied the dynamics and trend of the last extant population of great bustards Otis tarda in Africa. Moroccan great bustards are the southernmost population of this species, and thus show the characteristics of a peripheral population: small size, isolation and low gene flow. Available counts indicate a severe population decline (62% in the last 15 yr), as well as a contraction of the species’ distribution. We used a population viability analysis (PVA) to evaluate the quasi-extinction risk and to identify the most important threats. The estimated geometric growth rate of the more realistic of a set of possible scenarios was 0.87 (95% CI: 0.85, 0.89). This implies a 13% annual decline over 50 yr. However, projections derived from these results should be interpreted with caution, because models have a great deal of uncertainty and vital rates from Iberian populations may be different from those of the Moroccan population. PVA showed the negative consequence of human-induced mortality. According to the model that best fits our census data and if present threats remain in the coming years, this peripheral population could go extinct in ca. 20 yr. Agricultural intensification, infrastructure developments and new power lines in rural areas where the species occurs are causing habitat destruction and fragmentation and increasing artificial mortality. Urgent conservation measures, especially to reduce human-induced mortality, are needed to save African great bustards from extinction. We suggest that these findings can be generalized to other peripheral great bustard populations living in highly humanized landscapes.
Nefla, A. & Nouira, S. 2016. Environmental factors affecting the foraging behavior of herons in Ichkeul National Park, Tunisia. Waterbirds 39: 99–103. doi: 10.1675/063.039.0112
This study was carried out at Ichkeul National Park, Tunisia, during 2009 and 2010. The influence of environmental variables on the foraging behavior of three Ardeid species was studied. Grey Herons (Ardea cinerea) were the least active of the three species, having the greatest resting percentages in 2009 (55.0%) and 2010 (64.9%); they primarily used the “standing and wait” hunting behavior (68.5%). Great Egrets (A. alba) (93.6%) and Little Egrets (Egretta garzetta) (86.5%) primarily adopted a “walking slowly” strategy. Little Egrets also frequently used the “walking quickly” behavior, a more active hunting technique. Both Little and Great egrets varied their hunting behaviors according to water depth. In shallows, they used the “walking quickly” behavior, while in deeper waters they used the “standing and wait” behavior (Little Egret: r = -0.26, P < 0.001; Great Egret: r = -0.44, P < 0.01). For Little Egrets only, high temperature (F = 42.77, df = 1, P < 0.001) and high wind velocity (F = 63.81, df = 1, P < 0.001) promoted an active “walking quickly” hunting behavior, while high light intensity frequently promoted the “standing and wait” and “walking slowly” behaviors (F = 5.48, df = 1, P < 0.05).
Amezian, M. & El Khamlichi, R. 2016. Significant population of Egyptian Vulture Neophron percnopterus found in Morocco. Ostrich 87: 73–76.
The Egyptian VultureNeophron percnopterus population in Morocco has undergone a marked decline since the 1980s to the point of nearing local extinction in the twenty-first century. A field study of some possible sites for Egyptian Vultures was carried out over six days during June 2014 in the Middle Atlas Mountains, Morocco. We counted a total of 48 Egyptian Vultures at three different localities: two occupied breeding sites and one communal roost that hosted 40 vultures of different ages. A (probable) singe adult bird at the breeding site was located and a previously occupied site was also visited. A preliminary survey amongst local people indicated that threats faced by this species are predator poisoning in some areas, and the use of vulture parts for traditional medicine. Given that the species is considered globally Endangered and populations continue to decline in many areas, the discovered population reported here, although relatively small, is of national and regional (North-west Africa) importance. We expect this new situation will revive the hopes for studying and conserving this and other vulture species in Morocco and North-west Africa in general.
More details / Plus de détails:
The plight of the Egyptian Vulture and hopes for the future.
Traduit aussi en français: Les vautours au Maghreb: une situation critique et espoirs pour l’avenir.
Communal roost of Egyptian Vultures / Dortoir de Vautours percnoptères:
Hanane, S. (2016). Effects of location, orchard type, laying period and nest position on the reproductive performance of Turtle Doves (Streptopelia turtur) on intensively cultivated farmland. Avian Research 7: 4. doi: 10.1186/s40657-016-0039-0 (Open Access)
Until recently little was known about factors affecting reproductive parameters of the Turtle Dove (Streptopelia turtur) on intensively cultivated farmland in the Mediterranean area. In this study, the reproductive parameters of this game species were evaluated in relation to location, orchard type, laying period and nest position in central Morocco.
A total of 317 nests were found and analyzed across five breeding seasons (2004–2008) in the Haouz and Tadla regions, over two major agro-ecosystems made up of olive and orange orchards. Nest position, laying period, clutch size and the number of chicks hatched and fledged per nest were determined on 120 study plots. I used Generalized Linear Models (GLMs) with a Poisson distribution and a log link function, including the logarithm of the number of eggs in each clutch as an offset to model the number of chicks hatched and fledged per nest.
Clutch-size was not affected by location, orchard type, laying period or nest position. The number of chicks hatched per nest differed between orchard types; they were greater in olive orchards (1.33 ± 0.06) than in orange ones (1.03 ± 0.08), whereas the number of chicks fledged per nest consistently differed with laying period and orchard type, which were higher in the early laying period (1.22 ± 0.07) than in the late period (0.93 ± 0.08) and higher in olive orchards (1.22 ± 0.06) than in orange orchards (0.90 ± 0.06). Neither location nor nest position were related to variation in the fledging success of the Turtle Dove.
Olive orchards and the early laying period confer better nesting conditions than orange orchards and the late laying period. Although nest position could be different in each orchard type, it did not affect the breeding success of the Turtle Dove, suggesting that factors other than tree characteristics are influential. Further studies are needed to improve our understanding of the effects of anthropogenic disturbance, especially agricultural activities and hunting, on the productivity of Turtle Dove nests.