Conservation priorities for chukar partridge in Israel based on genetic diversity across an ecological gradient

Recent studies suggest that patterns of genetic diversity significantly influence the viability and persistence of local populations. Revealing and mapping spatial patterns of genetic diversity within species' ranges may be vital when defining criteria and prioritizing areas for conservation. Chukar Partridges (Alectoris chukar) in Israel occur along a steep ecogeographical gradient extending from mesic Mediterranean zones in the north to steppe and desert regions in the south. To rest the hypothesis that the most genetically diverse populations within a species' range occur within the ecotone, an area of transition between ecosystems where a sharp environmental gradient exists, we examined the allozyme diversity of chukars collected at five locations within the species' continuous range in each of 2 years. Based on 32 allozyme loci, the genetic diversity of chukars increased significantly, along a gradient from population in Mediterranean regions to those at the ecotone in the northern Negev desert, despite close geographical proximity among populations Genetic diversity As estimated by percent polymorphic loci, observed and expected heterozygosity, and mean number of alleles was not homogeneous among sampling localities: single and multilocus Hardy-Weinberg and linkage disequilibria increased along the gradient toward the ecotone. Populations exhibited some isolation by distance effects in the face of substantial gene flow. We therefore recommend that higher conservation priority be assigned to the Mediterranean-Negev ecotone area. For Chukar Partridges, it supports the highest overall genetic diversity across ecological gradients. Rapid urbanization of Israeli landscapes, and management of chukars in Israel within a metapopulation context is an urgent requirement

The effects of scaling on age, sex and size relationships in Red-legged Partridges

Wild birds differ in size according to their age and sex, adult birds being larger than juveniles. In the galliforms, males are larger than females, in contrast to some groups, such as the raptors, in which the females are larger. Size generally influences the rank hierarchy within a group of birds, although the age, sex, temperament and behaviour of an individual may override its size related rank order. The scaled size of birds according to age and sex affects their physiology and behaviour. Precise details of body-size differences by age and sex are poorly known in most partridge species. We measured 13,814 wild partridges in a homogenous population over 14 years of study to evaluate size differences within a uniform habitat and population management regime. We show that wild Red-legged Partridges have scaled mass, and body- and wing-lengths consistent with age/sex classes. Power functions between mass and body-length (as a proxy for walking efficiency), and between mass and wing-length (for flight efficiency) differ between juvenile females and males, and adult females and males. We discuss these findings and their physiological, behavioural and ecological implications.A.M. was supported by a Ramón y Cajal research contract by the Ministry of Economy and Competitiveness (RYC-2012-11867).Peer reviewe

Age and Sex Ratios in a High-Density Wild Red-Legged Partridge Population

The dynamics of a wild red-legged partridge population were examined over a 14-year period in Spain to identify patterns in age and sex ratios in relation to weather parameters, and to assess the importance of these parameters in population dynamics and management. The results gave age ratios of 1.07 (but 2.13 in July counts), juvenile sex ratios of 1.01 and adult sex ratios of 1.47. Overall, 12% more females were hatched and female juvenile mortality was 7.3% higher than in males. Sex differential mortality explains the 19.2% deficit in adult females, which are more heavily predated than males during the breeding period. Accordingly, age ratios are dependent on sex ratios and both are density dependent. Over time, ratios and density changes appear to be influenced by weather and management. When the habitat is well conserved, partridge population dynamics can be explained by a causal chain: weather operates on net primary production, thereby affecting partridge reproduction and predation and, as a result, age and sex ratios in the October population. A reduction in the impact of predation (i.e. the effects of ground predators on eggs, chicks and breeding females) is the key factor to improve the conservation of partridge populations and associated biological processes