O. M. Kulikova

Rough-legged buzzards, Arctic foxes and red foxes in a tundra ecosystem without rodents.

Small rodents with multi-annual population cycles strongly influence the dynamics of food webs, and in particular predator-prey interactions, across most of the tundra biome. Rodents are however absent from some arctic islands, and studies on performance of arctic predators under such circumstances may be very instructive since rodent cycles have been predicted to collapse in a warming Arctic. Here we document for the first time how three normally rodent-dependent predator species—rough-legged buzzard, arctic fox and red fox – perform in a low-arctic ecosystem with no rodents. During six years (in 2006-2008 and 2011-2013) we studied diet and breeding performance of these predators in the rodent-free Kolguev Island in Arctic Russia. The rough-legged buzzards, previously known to be a small rodent specialist, have only during the last two decades become established on Kolguev Island. The buzzards successfully breed on the island at stable low density, but with high productivity based on goslings and willow ptarmigan as their main prey – altogether representing a novel ecological situation for this species. Breeding density of arctic fox varied from year to year, but with stable productivity based on mainly geese as prey. The density dynamic of the arctic fox appeared to be correlated with the date of spring arrival of the geese. Red foxes breed regularly on the island but in very low numbers that appear to have been unchanged over a long period – a situation that resemble what has been recently documented from Arctic America. Our study suggests that the three predators found breeding on Kolguev Island possess capacities for shifting to changing circumstances in low-arctic ecosystem as long as other small - medium sized terrestrial herbivores are present in good numbers.

Harmonizing circumpolar monitoring of Arctic fox: benefits, opportunities, challenges and recommendations

ABSTRACT The biodiversity working group of the Arctic Council has developed pan-Arctic biodiversity monitoring plans to improve our ability to detect, understand and report on long-term change in Arctic biodiversity. The Arctic fox (Vulpes lagopus) was identified as a target of future monitoring because of its circumpolar distribution, ecological importance and reliance on Arctic ecosystems. We provide the first exhaustive survey of contemporary Arctic fox monitoring programmes, describing 34 projects located in eight countries. Monitored populations covered equally the four climate zones of the species’ distribution, and there were large differences between populations in long-term trends, multi-annual fluctuations, diet composition, degree of competition with red fox and human interferences. Den density, number of active dens, number of breeding dens and litter size were assessed in almost all populations, while projects varied greatly with respect to monitoring of other variables indicative of population status, ecosystem state or ecosystem function. We review the benefits, opportunities and challenges to increased integration of monitoring projects. We argue that better harmonizing protocols of data collection and data management would allow new questions to be addressed while adding tremendous value to individual projects. However, despite many opportunities, challenges remain. We offer six recommendations that represent decisive progress toward a better integration of Arctic fox monitoring projects. Further, our work serves as a template that can be used to integrate monitoring efforts of other species, thereby providing a key step for future assessments of global biodiversity.

The effect of the structure of aliphatic diamines on their interaction with zinc porphyrinates

The complex formation of zinc 2,8,12,18-tetramethyl-3,7,13,17-tetraethylporphyrinate, 5,17-bis(zinc 2,8,12,18-tetramethyl-3,7,13,17-tetraethyl-10-phenylporphyrinate)-25,27-dimethoxy-26,28-dihydroxycalic-[4]-arene, and 5,17-bis(zinc 2,8,12,18-tetramethyl-3,7,13,17-tetraethyl-10-phenylporphyrinate)-25,27-dimethoxy-26,28-crwon-[6]-calix-[4]-arene with 1,2-diaminoethane, 1,3-diaminopropane, and 1,2-di-(dimethylamino)ethane in toluene was studied by spectrophotometric molar ratio method and 1H NMR. The effect of the diamine structure on the formation of “internal” and “external” porphyrinate-ligand complexes of the composition 1 :1 and 1 :2 was established. The stability constants of the complexes obtained were calculated and the concentration intervals of their formation were determined.

Synthesis and properties of ms- and β-substituted Pt(II) and Pt(IV) tetraphenylporphyrinates

The interaction of 5,10,15,20-tetraphenylporphyrin, 5,10,15,20-tetra-(4-chlorophenyl)porphyrin, 2-bromo-5,10,15,20-tetraphenylporphyrin, and 2,3,12,13-tetrabromo-5,10,15,20-tetraphenylporphyrin with platinum(II) chloride in boiling phenol has been studied. The corresponding platinum(II) porphyrinates have been synthesized; their subsequent treatment with bromine in chloroform resulted in platinum(IV) porphyrinates. The Pt(II) and Pt(IV)(Br)2 porphyrinates have been identified by elemental analysis, electron absorption, IR, and 1H NMR spectroscopy.

Assessing the causes of breeding failure among the rough-legged buzzard ( Buteo lagopus ) during the nestling period

When food becomes scarce, the youngest nestlings in facultatively siblicidal raptor species typically die and such events are usually attributed to siblicide. Here we present results from an investigation in the Arctic tundra, in which rough-legged buzzard (Buteo lagopus) breeding success was monitored with regular visits to nests and time-lapse cameras that continuously recorded the activity of chicks and their parents. The study took place in the Nenetsky Nature Reserve (68°20′N, 53°18′E) in the Russian Arctic, in 2007 10. It included 26 cases of chick mortality in 19 nests. The camera monitoring led us to discover instances of scavenging of chicks that had died due to starvation or bad weather in two nests. Camera monitoring also led us to discover how a sequence of abrupt weather shifts, between hot and sunny conditions and heavy rain, probably caused the death of nestlings in two nests. Detailed nest monitoring is required to avoid the mistaken attribution of such deaths to siblicide. Such extreme weather events may become more common with climate change and represent a new potential factor affecting rough-legged buzzards breeding success in the southern Arctic.

Determination of Acidity of Di-, Tri-, and Tetraazaporphyrins in Dimethyl Sulfoxide-Potassium Cryptate Medium

Acidic properties of 10,20-diaza-3,7,13,17-tetramethyl-2,8,12,18-tetra-n-hexylporphyrin, 2,7,12,17-tetra-t-butyltetrabenzo-5,10,15-triazaporphyrin and octa(n-amyloxy)phthalocyanine in the system of dimethyl sulfoxide-potassium cryptates (DMSO-K[222]OH) at ambient temperature was investigated by the method of spectrophotometric titration. The porphyrins in the DMSO-K[222]OH medium were shown to dissociate sequentially forming mono- and dianions in two steps. The concentration ranges of existence of the anionic forms and the acidity sequence of the studied meso-aza-substituted porphyrins were investigated.

Synthesis of Cyclophane-Like Porphyrin-Calix(4)pyrrole Conjugates

New cyclophane-like porphyrin-calix[4]pyrrole conjugates were synthesized on the basis of meso-ethynyloctaethylporphyrin, and their physicochemical properties were studied.

Supramolecular complexes of carboxy-substituted zinc porphyrinates with triethylenediamine

Abstractα,α-and α,β-Atropoisomers of zinc 5,15-bis(2-carboxyphenyl)octaalkylporphyrinate were obtained, and their complex formation with triethylenediamine in toluene was studied. The α,α-atropoisomer is present in the solution as a supramolecular dimer and forms a 1:1 complex with the two-centered nitrogen-containing base. The complex formation of the undimerized α,β-atropoisomer with triethylenediamine can give 2:1 or 1:1 complexes, depending on the reagent ratio. The stability constants of the complexes and the concentration ranges of their formation were determined by means of spectrophotometric titration and 1H NMR spectroscopy.

Synthesis, spectra, and complexing properties of polyoxyethylene-substituted 5,15-diphenylporphyrins

Porphyrins with two opposite meso-phenyl substituents of the macroring linked via o-positions by polyoxyethylene bridges of various lengths were prepared. Their spectra and complexing properties toward Zn2+ and 1,4-diazabicyclo[2.2.2]octane were examined. The rate constants of formation and stability constants of the corresponding complexes were determined, and the concentration ranges of their formation were evaluated.

One and two point binding of organic bases molecules by meso-nitro substituted Zn-octaethylporphyrins

A study of complex formation of Zn-octaethylporphyrin and its mono-, di-, tri- and tetra-nitro meso-substituted derivatives towards propylamine, 1,3-diaminopropane, 2-(4-imidazolyl)-ethylamine and 1,4-diazabicyclo[2.2.2]octane was carried out by UV-vis titration method and 1H NMR. It has been determined that the nitro-substituted porphyrin receptors form with 1,3-diaminopropane and 2-(4-imidazolyl)-ethylamine 1:1 complexes with two points of binding. Individual contributions of a donor–acceptor interactions and a hydrogen bonding into a total energy of the complexes formation have been estimated. It has been shown that due to a good geometric match between the host–guest molecules the tetra-nitro substituted Zn-porphyrin has maximum binding ability towards the 1,3-diaminopropane, and the tri-nitro substituted Zn-porphyrin effectively binds the 2-(4-imidazolyl)-ethylamine.