Mammals and habitat disturbance: the case of brown hare and wildfire.

Ecosystem disturbances, such as wildfires, are driving forces that determine ecology and conservation measures. Species respond differentially to wildfires, having diverse post-fire population evolution. This study reports, for first time, the responses of brown hare (Lepus europaeus Pallas, 1778) to wildfires. Hare relative abundance, age ratio, diet quality, body condition, and diseases were studied. Fire influence on vegetation was calculated at a micro-scale level. Hare abundance was lower the first year after wildfires in burned relative to unburned areas. The reverse was found in the second year when hare abundance was higher in burned areas. Hare abundance in burned areas was also higher in the third and fourth years. In the fifth and sixth years after wildfire no significant difference was found in abundance. At a micro-scale level, higher numbers of hare feces were counted in places with greater wildfire influence on vegetation. Age ratio analysis revealed more juveniles in burned areas, but the same number of neonates in burned and unburned areas, indicating lower mortality of juveniles in burned areas. Reduced predation in burned areas provides the most plausible explanation for our findings.

Mercury in white stork (Ciconia ciconia) chick feathers from northeastern Mediterranean areas in relation to age, brood size, and hatching order.

Mercury (Hg) levels in white stork (Ciconia ciconia) feathers collected in the mid-1990s from five northeastern Mediterranean (Greece) areas varied, with mean ranges between 301 ng g(-1) dry weight (dw) (Pinios River) and 1911 ng g(-1) dw (Sperchios Delta). A significant increase of Hg levels in chick feathers with age (surrogated by bill size) was found in the Evros and Pinios River areas, a nonsignificant increase in the Amvrakikos Gulf and the Epirus Region, and a marginally significant decrease in the Sperchios Delta area. For combined data of 1993 and 1995, Hg concentrations did not differ significantly in relation to hatching order among broods but differed significantly in relation to brood size being higher in 4-chick broods than those in 3-chick broods. All 10 areas formed 4 groups with levels mutually significantly different. Highest levels were detected in the Evros, Axios, and Sperchios riverine areas, whereas the lowest levels occurred at Drama plain, which lacks large water bodies in its vicinity. Levels were lower than those associated with intoxication to other ciconiiform species.

Organochlorine and mercury contamination in fish tissues from the River Nestos, Greece.

Polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) isomers, dichlorodiphenyltrichloroethane (DDT) and its metabolites, other organochlorine pesticides such as hexachlorobenzene (HCB), chlordane compounds (CHLs, including trans-chlordane and cis- and trans-nonachlor) and the heavy metal mercury were quantified in muscle and liver of the European chub (Leuciscus cephalus, Linnaeus, 1758) and in the muscle of the barbel (Barbus cyclolepis, Heckel, 1837) at two sampling sites of the River Nestos, Greece. PCBs in muscle and DDTs in the liver tissues were the predominant organochlorinated contaminants. Among the PCBs, congeners 47 (up to 9.60 ng g(-1) wet wt.), 180 (up to 1.15 ng g(-1) wet wt.) and 190 (up to 1.50 ng g(-1) wet wt.) were the most frequent and abundant. The contamination degree by the sum of PCBs on the fish tissue samples from the River Nestos is lower or similar to PCB levels found in other ecosystems. Among the organochlorine pesticides, essentially only p,p'-DDD, p,p'-DDE and alpha-, beta- and gamma-HCH were found, with the former appearing at mean levels up to 30.71 ng g(-1) wet wt. From a public health standpoint, residue organochlorine pesticide levels from our work are considerably lower than the recommended tolerance limits. Finally, mean values of Hg in chub were significant lower (up to 31.04 ng g(-1) wet wt.) compared to those detected on barbel (up to 169.27 ng g(-1) wet wt.). The concentrations of Hg in fresh water fish from the River Nestos did not exceed WHO and US EPA health guidelines, and were suitable for human consumption.