Why do zoos attract crows? A comparative study from Europe and Asia

Crows have successfully colonized many cities, and urban zoos have been important in this process. To evaluate why zoos attract crows, we quantified crow numbers and behavior in three zoos in Europe (Debrecen, Edinburgh, Vienna) and one in Asia (Sapporo). Data were collected in 445 surveys over 297 days in summer 2014 and winter 2014–2015. We found that crow numbers were highest in Vienna, intermediate in Debrecen and Edinburgh and lowest in Sapporo, increased significantly from summer to winter (Debrecen, Edinburgh, Vienna), and from mornings to afternoons (Debrecen, Sapporo, Vienna), and were higher in sunny weather than in cloudy weather with precipitation and when visitor numbers were low (Debrecen, Vienna). The crows' use of natural food was highest in Vienna, intermediate in Edinburgh and Sapporo, and low in Debrecen. The use of anthropogenic food was high in Debrecen and Sapporo, where the availability of open grassy areas typically used by crows for natural foraging was low. In Sapporo, food availability was more limited than in other zoos, resulting in strong territoriality and few crows in summer, which decreased further in winter. Our study indicates that crows are primarily attracted to zoos by food availability and secondarily by breeding opportunities and that the relative importance of natural versus anthropogenic food sources may vary with zoo habitat structure. Our study draws attention to a previously overlooked role of zoos in urban biodiversity conservation. It may also provide useful information for the management of crow populations, if necessary, and for the planning of urban areas.     

β-Citraurin epoxide,a new carotenoid from valencia orange peel

A new minor carotenoid, β-citraurin epoxide (3-hydroxy-5,6-epoxy-5,6-dihydro-8′-apo-β-caroten-8′-al) and several isomers of violaxanthin (5,6,5′,6′-diepoxy-5,6,5′,6′-tetrahydro-β,β-caroten-3,3′-diol) have been identified in Valencia orange peel. The previously reported occurrence of apo-10′-violaxanthal (3-hydroxy- 5,6-epoxy-5,6-dihydro-10′-apo-β-caroten-10′-al) and apo-12′-violaxanthal (3-hydroxy-5,6-epoxy-5,6-dihydro- 12′-apo-β-caroten-12′-al) has been confirmed, and their syntheses are described. The quantitative determination of the carotenoids has also been performed.     

Attractivity of various artificial light sources to caddisfly (Trichoptera) species and its importance in their sampling and conservation

Journal of Insect Conservation - The artificial light sources are useful tools for sampling night active insects, however, they also possess potential environmental risks in their habitats. To test...     

The effect of gender and age on growth hormone replacement in growth hormone-deficient patients.

We analyzed the effect of growth hormone replacement therapy (36 months) analyzed at a dose adjusted to maintain serum insulin-like growth factor-I level between the median and the upper end of the age-related reference range on bone mineral density, body composition, and carbohydrate metabolism with respect to gender and age in 20 adult patients (9 women, 11 men, mean age: 43 years, range: 21-61 years). The lumbar and femoral T-score was increased after 12 and after 18 months of therapy respectively in men (p < 0.001 and p = 0.002), but did not changed significantly in women. The increase of femoral T-score was greater in young men (< or = 45 years, n = 6) than old men (> 45 years, n = 5, p < 0.001). Body fat was lower in men than in women after 6 months (p = 0.002). The waist/hip ratio only decreased in women (p = 0.044). The waist circumference decreased in both genders after 6 months of therapy (p < 0.001), but more markedly in females than in males (p < 0.05). The sum of skinfold thicknesses was reduced in males after 6 months of therapy (p < 0.001). Changes in body composition parameters measured were independent of age. The glycosylated hemoglobin increased without sex or age difference after 12 months of initiation of therapy (p < 0.001), but fasting glucose and insulin levels did not change during the therapy. Our results indicate that the effect of growth hormone replacement on bone mineral content in adults is age- and gender-dependent, gender dependent on body composition, but independent of age and gender on carbohydrate metabolism.     

Effect of mitochondrial toxins on evoked somatosensory activity in rats

Mitochondrial toxins represent an interesting group of neurotoxicants related both to causation and modelling of central nervous damage. 3-nitropropionic acid (3NP), a neurotoxin of herbal and microfungal origin, inhibits succinate dehydrogenase leading thereby to various biochemical and morphological alterations in the brain. Experimental animals treated by 3NP are used to model Huntington’s disease. Manganese, often present in occupational settings and as environmental pollutant, inhibits complex II and III of the mitochondria and is known to cause Parkinson-like CNS damage. In this work, rats were administered a single acute dose of Mn (50 mg Mn²⁺/kg body weight) or 3-NP (20 mg/kg b.w.) and the alterations of the somatosensory cortical evoked potential elicited by stimulation of the whisker pad and the tail base were observed, together with the changes of the action potential in the tail nerve. Latency and amplitude of the two cortical responses changed in parallel, while those of the tail nerve response remained more or less unaltered. The two mitochondrial toxins studied seem to exert their action centrally, primarily on synaptic transmission, rather than peripherally. Recording of evoked activity could be used to follow-up the nervous system effects of mitochondrial toxins, but it requires further investigation.