The development of the Rook's(Corvus frugilegus)colony in the face of shifting spring phenology

Many birds species breed in colonies.One of the species in the Corvidae family nesting in groups is the Rook(Corvus frugilegus).The construction of the nest is costly for birds and needs high energy expenditure.Therefore,birds should optimize the time of nest building in relation to environmental,especially weather,conditions.Furthermore,birds should adapt their breeding phenology,including the date of starting the construction of nests for climate change.We observed the dynamics of increasing numbers of nests in a colony of Rooks in relation to air temperature,wind,rainfall,snowfall and day-length(indirect indicator of photoperiodism).Observations were carried out during three breeding seasons(2015-2017)in a large rookery in a big city in north-eastern Poland.The increase in the number of nests was correlated only with day length and no effect of climatic factors on the number of nests in the colony was observed.Number of nests varied significantly between successive years of research.In the case of the Rook(predictable breeders),the photoperiod seems to be the most important factor influencing breeding behavior,especially nest construction.In the last three decades,increasing temperature and time of spring phases have advanced and have influenced changes in the phenology of the availability of food resources.Simultaneously,a rapid decline in the numbers of breeding pairs of the Rook in Poland has been observed,especially in the last three decades.Conservative attachment to the length of the day,which is the main factor responsible for the development of the breeding colony,makes the Rook appear to be a species with low plasticity in the face of rapid climate changes.Thus,we suggest that may indirectly influence the decrease in the breeding population of the Rook.

Invasion of the raccoon dog Nyctereutes procyonoides in Europe： History of colonization, features behind its success, and threats to native fauna

We aimed to review the history of the introduction and colonization of the raccoon dog Nyctereutes procyonoides in Europe, the features behind its successful expansion and its impact on native fauna. The raccoon dog quickly colonized new areas after being introduced to the European part of the former Soviet Union. Today it is widespread in Northern and Eastern Europe and is still spreading in Central Europe. Features behind its success include its adaptability, high reproductive potential, omnivory, hibernation in northem areas, multiple introductions with 〉 9000 individuals from different localities, and tendency to wander enabling gene flow between populations. Firm evidence of the raccoon dog＇s negative impact on native fauna, such as a reduction in bird populations, is still scarce. Raccoon dogs may destroy waterfowl nests, although a nest predation study in Latvia did not confirm this. Predator removal studies in Finland suggested that the raccoon dog＇s impact on game birds is smaller than expected. However, raccoon dogs may have caused local extinction of frog populations, especially on islands. Raccoon dogs may compete with other carnivores for food, for example for carrion in winter, or for the best habitat patches. In northern Europe potential competitors include the red fox Vulpes vulpes and the badger Meles meles, but studies of their diets or habitat preferences do not indicate severe competition. The raccoon dog is an important vector of diseases and parasites, such as rabies, Echinococcus mul-tilocularis and Trichinella spp. and this is no doubt the most severe consequence arising from the spread of this alien species in Europe [Current Zoology 57 （5）： 584-598, 2011].

Does kinship affect spatial organization in a small and isolated population of a solitary felid: The Eurasian lynx?

Social organization in wild carnivores is mostly determined by patterns of family bonds,which may shape the degree of relatedness among individuals in the population.We studied kinship in a small and isolated population of a solitary carnivore,the Eurasian lynx(Lynx lynx)to evaluate its effect on spatial distribution of individuals.We investigated the relationship between spatial location and pair-wise kinship among 28 lynx individuals iden­tified in 2004-2011 by telemetry,non-invasive sampling and genotyping with the use of 12 autosomal microsat­ellites in the Białowieża Primeval Forest,Poland.The average relatedness of the lynx population was relatively low(Lynch and Ritland’s R=0.03).Females were significantly more related to each other than males with other males.The inferred pedigree showed that the population was dominated by only 2 familial groups.We did not find significant correlations between the relatedness and the extent of home range overlap or the straight-line distances between the home ranges’central points.These results suggest that the dynamics of kinship in this sol­itary felid may not differ from the random mating processes described in social carnivores.Although the chanc­es of random mating could be limited to a few resident males and females,the presence of unrelated floaters may provide a“breeding buffer”that may prevent an increase of relatedness and likely inbreeding in the pop­ulation.This system is likely to fail in preserving genetic diversity in small,highly isolated populations;there­fore,restoring habitat connectivity is crucial to ensure sufficient immigration from neighboring populations.

Penis size and sperm quality,are all bats grey in the dark?

Penises play a key role in sperm transport and in stimulating female genitals.This should impact post-copulatory competition,and expose penis characteristics to sexual selective pressures.Studies of male genitalia have repeatedly reported negative static allometries,which mean that,within species,large males have disproportionally small genitals when compared with smaller individuals.Males of some sperm-storing bat species may stand as an exception to such a pattern by arousing from hibernation to copulate with torpid females.The selection for large penises might take place,if a long organ provides advantages during post-copulatory competition and/or if females have evolved mechanisms allowing the choice of sire,relying on characters other than pre-copulatory traits(e.g.,penis size).In this study,we measured dimensions of the erected penis in 4 sperm-storing bat species.Furthermore,we collected sperm and evaluated the link between penis dimensions and sperm velocity.Our results revealed steep allometric slopes of the erected penis length in Barbastella barbastellus and an inverse allometry of penis head width in Myotis nattereri.More detailed studies of copulatory behavior are urgently needed to explain the range of observed scaling relations.Furthermore,penis head width correlates with sperm velocity in Plecotus auritus.For this last species,we propose that penis shape might act as a marker of male fertility.

Continuous growth through winter correlates with increased resting metabolic rate but does not affect daily energy budgets due to torpor use

Small mammals that are specialists in homeothermic thermoregulation reduce their self-maintenance costs of normothermy to survive the winter.By contrast,heterothermic ones that are considered generalists in thermoregulation can lower energy expenditure by entering torpor.It is well known that different species vary the use of their strategies to cope with harsh winters in tem-perate zones;however,ittle is still known about the intraspecific variation within populations and the associated external and internal factors.We hypothesized that yellow-necked mice Apodemus flavicollis decrease their resting metabolic rate(RMR)from autumn to winter,and then increase it during spring.However,since the alternative for seasonal reduction of RMR could be the develop-ment of heterothermy,we also considered the use of this strategy.We measured body mass(mp),RMR,and body temperature(Tb)of mice during 2 consecutive years.In the 1st year,mice decreased whole animal RMR in winter,but did not do so in the 2nd year.All mice entered torpor during the 2nd winter,whereas only a few did so during the first one.Mice showed a continuous in-crease of mb,which was steepest during the 2nd year.The relationship between RMR and mb var-ied among seasons and years most likely due to different mouse development stages.The mb gain at the individual level was correlated positively with RMR and heterothermy.This indicates that high metabolism in winter supports the growth of smaller animals,which use torpor as a compen-satory mechanism.Isotope composition of mice hair suggests that in the 1st year they fed mainly on seeds,while in the 2nd,they likely consumed significant amounts of less digestible herbs.The study suggests that the use of specialist or generalist thermoregulatory strategies can differ with environmental variation and associated differences in developmental processes.