Landscape context and little bustard abundance in a fragmented steppe: implications for reserve management in mosaic landscapes

International audienceIn mosaic landscapes, patch use by animals may depend on features associated with neighbouring patches, e.g. resources or predators. This is of concern for species living in fragmented remnants of natural habitats surrounded by man-modified habitats. We studied how landscape context influenced habitat use by a lekking grassland bird, the little bustard, in a landscape where protected patches of natural steppe were interspersed with improved pastures suitable to bustards, and other unsuitable habitats. At a scale equivalent to a lekking site (30–70 ha), the abundance of displaying males and nesting females on steppe plots increased with increasing availability of improved pastures within 1 km of plots. This concentration of breeding bustards on steppe habitat around modified pastures may partly result from the species' lekking system. We emphasize that increasing the suitability of managed habitats around protected natural areas may help in maintaining viable populations of native species by providing additional resources or breeding sites

Morphometrics of Houbara Bustards Chlamydotis spp: Sexual Size Dimorphism, Seasonal Changes and Differences between Species

[EN] This study presents for the first time morphometric data from large samples of free-living individuals of Chlamydotis bustards (448 MacQueen's Bustards, 288 African Houbaras, and 53 Canarian Houbaras). Linear measurements were largest in MacQueen's Bustards, intermediate in African Houbaras and smallest in Canarian Houbaras, with differences between the largest and smallest species ranging from 4.5% to 13.9%. Male MacQueen's Bustards were also the heaviest (4% and 15.5% heavier than, respectively, African and Canarian Houbara males) but, unexpectedly, there were no significant weight differences among females of the three bustards. Males of the three bustards were significantly larger than females in all linear measurements and weight. These between-species/subspecies differences are consistent with a slight trend to insular dwarfism that probably selects for smaller size in the Canarian subspecies. Males are larger and heavier than females in the three bustards, as expected in polygynous species, suggesting a moderate effect of sexual selection acting on male size. Finally, the slightly higher sexual size dimorphism values observed in wings and tarsi in MacQueen's bustards compared to both subspecies of African Houbaras are in line with the allometric constraint hypothesis.[ES] Este estudio presenta por primera vez datos biométricos de muestras significativas de individuos silvestres de avutardas del género Chlamydotis (448 avutardas de MacQueen, 288 hubaras africanas y 53 hubaras canarias). La avutarda de MacQueen presentó las medidas lineales mayores, con valores intermedios en la subespecie nominal de hubara africana y menores en la subespecie insular canaria, con diferencias del 4,5% al 13,9% entre la primera y la última. Los machos de avutarda de MacQueen fueron también los más pesados (un 4% y un 15,5% respectivamente más que los de hubara africana y canaria), pero no hubo diferencias de peso significativas entre las hembras de las tres avutardas. Los machos de las tres avutardas mostraron un tamaño y un peso significativamente mayores que las hembras. Estas diferencias entre especies y subespecies son consistentes con una ligera tendencia al enanismo insular, que probablemente ejerce una selección hacia un menor tamaño en la subespecie canaria. Los machos fueron más grandes y pesados que las hembras en las tres avutardas, como es esperable en especies poligínicas, lo que sugiere un efecto moderado de la selección sexual sobre el tamaño de los machos. Por último, los valores de dimorfismo sexual ligeramente superiores observados en las alas y los tarsos de las avutardas de MacQueen en comparación con las dos subespecies de hubaras africanas están en consonancia con la hipótesis de la restricción alométrica.Peer reviewe

A new galago species for South Africa (Primates: Strepsirhini: Galagidae).

9 pagesInternational audienceThe primate fauna of South Africa has historically been viewed as comprising three diurnal cercopithecoid taxa — chacma baboons (Papio ursinus), vervet (Chlorocebus pygerythrus) and samango monkeys (Cercopithecus albogularis) — and two nocturnal lorisoid species — the thick-tailed greater galago (Otolemur crassicaudatus) and the southern lesser galago (Galago moholi). Here we report the positive identification of a third galago species within South Africa's borders: the Mozambique dwarf galago or Grant's galago, Galagoides granti (Thomas and Wroughton, 1907). The taxon was previously held to be restricted to Mozambique, eastern Zimbabwe, Malawi and Tanzania, but we have also observed it in the sand forest of Tembe Elephant Park and the Tshanini Community Reserve, near the Mozambique border. The species was formerly mistaken for Galago moholi, erroneously (we believe) extending the range of the latter species into northern KwaZulu-Natal. In South Africa the two small galagos are unlikely to have overlapping ranges: Galago moholi prefers dry savanna woodlands, whereas Galagoides granti is apparently confined to dry sand forest. However, both species may coexist with the larger and more widespread Otolemur crassicaudatus, an inhabitant of moist savanna, forest edge and thicket. The true South African ranges of both small galago species need to be ascertained