Most birds incubate their eggs to allow embryo development. This behaviour limits the ability of ... more Most birds incubate their eggs to allow embryo development. This behaviour limits the ability of adults to perform other activities. Hence, incubating adults trade-off incubation and nest protection with foraging to meet their own needs. Parents can either cooperate to sustain this trade-off or incubate alone. The main cause of reproductive failure at this reproductive stage is predation and adults reduce this risk by keeping the nest location secret. Arctic sandpipers are interesting biological models to investigate parental care evolution as they may use several parental care strategies. The three main incubation strategies include both parents sharing incubation duties ("biparental"), one parent incubating alone ("uniparental"), or a flexible strategy with both uniparental and biparental incubation within a population ("mixed"). By monitoring the incubation behaviour in 714 nests of seven sandpiper species across 12 arctic sites, we studied the relationship between incubation strategy and nest predation. First, we described how the frequency of incubation recesses (NR), their mean duration (MDR), and the daily total duration of recesses (TDR) vary among strategies. Then, we examined how the relationship between the daily predation rate and these components of incubation behaviour varies across strategies using two complementary survival analysis. For uniparental and biparental species, the daily predation rate increased with the daily total duration of recesses and with the mean duration of recesses. In contrast, daily predation rate increased with the daily number of recesses for biparental species only. These patterns may be attributed to two independent mechanisms: cryptic incubating adults are more difficult to locate than unattended nests and adults departing the nest or feeding close to the nest can draw predators' attention. Our results demonstrate that incubation behaviour as mediated by incubation strategy has important consequences for sandpipers' reproductive success.
Regreso a la Vida Silvestre: Individuos Migratorios de Falco peregrinus Reproduciendose en Artico... more Regreso a la Vida Silvestre: Individuos Migratorios de Falco peregrinus Reproduciendose en Artico de Eurasia Luego de su Uso en Cetreria Arabica Durante siglos los cetreros han capturado en Medio Oriente individuos migratorios de Falco peregrinus provenientes de poblaciones reproductivas del norte de Eurasia, pero se sabe poco sobre el destino de las aves que son liberadas o que se pierden durante la epoca de caza invernal. Reportamos ocho intentos de cria por parte de siete hembras de F. peregrinus que fueron utilizadas previamente en la cetreria arabica, y que se reproducen en el Artico ruso. Utilizando evidencia proveniente de aves usadas en cetreria, junto con datos de telemetria satelital y microchips implantados, inferimos que la zona de la tundra artica que se extiende desde la peninsula de Yamal (67°E) hasta la peninsula central de Taimyr (100°E) es la principal region de cria de los individuos de F. peregrinus utilizados por los cetreros arabes. Estimamos que al menos 2.8% de las hembras que anua...
ABSTRACT Northern small rodents are well known for their population cycles which represent a key ... more ABSTRACT Northern small rodents are well known for their population cycles which represent a key process for the functioning of arctic and boreal ecosystems. Habitat use often changes in the course of the cycle. Higher densities can either lead to spill-over into secondary habitats or to increased habitat specificity because of interspecific competition. Here we investigate whether voles in the shrub tundra of southern Yamal exhibit density dependent habitat use. Voles were trapped at the Erkuta Tundra Monitoring Site (N 68.2°, E 69.2°) in three characteristic habitats over five years covering all phases of the population cycle. Our analyses focused on the two most numerous species Microtus gregalis (52% of individuals caught) and M. middendorffii (36%). A small-scale spill-over effect was observed for M. gregalis, which increasingly used the open habitat adjacent to their preferred willow thickets at high abundance. At a larger scale no such effect was observed for the two Microtus species–a result which is explained by the overall moderate densities of voles and the large spatial extent of the primary habitat of M. middendorffii: moist moss dwarf shrub tundra.
The Qinghai-Tibet Plateau (QTP), possesses a climate as cold as that of the Arctic, and also pres... more The Qinghai-Tibet Plateau (QTP), possesses a climate as cold as that of the Arctic, and also presents uniquely low oxygen concentrations and intense ultraviolet (UV) radiation. QTP animals have adapted to these extreme conditions, but whether they obtained genetic variations from the Arctic during cold adaptation, and how genomic mutations in non-coding regions regulate gene expression under hypoxia and intense UV environment, remain largely unknown. Here, we assemble a high-quality saker falcon genome and resequence populations across Eurasia. We identify female-biased hybridization with Arctic gyrfalcons in the last glacial maximum, that endowed eastern sakers with alleles conveying larger body size and changes in fat metabolism, predisposing their QTP cold adaptation. We discover that QTP hypoxia and UV adaptations mainly involve independent changes in non-coding genomic variants. Our study highlights key roles of gene flow from Arctic relatives during QTP hypothermia adaptation,...
Most birds incubate their eggs to allow embryo development. This behaviour limits the ability of ... more Most birds incubate their eggs to allow embryo development. This behaviour limits the ability of adults to perform other activities. Hence, incubating adults trade-off incubation and nest protection with foraging to meet their own needs. Parents can either cooperate to sustain this trade-off or incubate alone. The main cause of reproductive failure at this reproductive stage is predation and adults reduce this risk by keeping the nest location secret. Arctic sandpipers are interesting biological models to investigate parental care evolution as they may use several parental care strategies. The three main incubation strategies include both parents sharing incubation duties ("biparental"), one parent incubating alone ("uniparental"), or a flexible strategy with both uniparental and biparental incubation within a population ("mixed"). By monitoring the incubation behaviour in 714 nests of seven sandpiper species across 12 arctic sites, we studied the relationship between incubation strategy and nest predation. First, we described how the frequency of incubation recesses (NR), their mean duration (MDR), and the daily total duration of recesses (TDR) vary among strategies. Then, we examined how the relationship between the daily predation rate and these components of incubation behaviour varies across strategies using two complementary survival analysis. For uniparental and biparental species, the daily predation rate increased with the daily total duration of recesses and with the mean duration of recesses. In contrast, daily predation rate increased with the daily number of recesses for biparental species only. These patterns may be attributed to two independent mechanisms: cryptic incubating adults are more difficult to locate than unattended nests and adults departing the nest or feeding close to the nest can draw predators' attention. Our results demonstrate that incubation behaviour as mediated by incubation strategy has important consequences for sandpipers' reproductive success.
Regreso a la Vida Silvestre: Individuos Migratorios de Falco peregrinus Reproduciendose en Artico... more Regreso a la Vida Silvestre: Individuos Migratorios de Falco peregrinus Reproduciendose en Artico de Eurasia Luego de su Uso en Cetreria Arabica Durante siglos los cetreros han capturado en Medio Oriente individuos migratorios de Falco peregrinus provenientes de poblaciones reproductivas del norte de Eurasia, pero se sabe poco sobre el destino de las aves que son liberadas o que se pierden durante la epoca de caza invernal. Reportamos ocho intentos de cria por parte de siete hembras de F. peregrinus que fueron utilizadas previamente en la cetreria arabica, y que se reproducen en el Artico ruso. Utilizando evidencia proveniente de aves usadas en cetreria, junto con datos de telemetria satelital y microchips implantados, inferimos que la zona de la tundra artica que se extiende desde la peninsula de Yamal (67°E) hasta la peninsula central de Taimyr (100°E) es la principal region de cria de los individuos de F. peregrinus utilizados por los cetreros arabes. Estimamos que al menos 2.8% de las hembras que anua...
ABSTRACT Northern small rodents are well known for their population cycles which represent a key ... more ABSTRACT Northern small rodents are well known for their population cycles which represent a key process for the functioning of arctic and boreal ecosystems. Habitat use often changes in the course of the cycle. Higher densities can either lead to spill-over into secondary habitats or to increased habitat specificity because of interspecific competition. Here we investigate whether voles in the shrub tundra of southern Yamal exhibit density dependent habitat use. Voles were trapped at the Erkuta Tundra Monitoring Site (N 68.2°, E 69.2°) in three characteristic habitats over five years covering all phases of the population cycle. Our analyses focused on the two most numerous species Microtus gregalis (52% of individuals caught) and M. middendorffii (36%). A small-scale spill-over effect was observed for M. gregalis, which increasingly used the open habitat adjacent to their preferred willow thickets at high abundance. At a larger scale no such effect was observed for the two Microtus species–a result which is explained by the overall moderate densities of voles and the large spatial extent of the primary habitat of M. middendorffii: moist moss dwarf shrub tundra.
The Qinghai-Tibet Plateau (QTP), possesses a climate as cold as that of the Arctic, and also pres... more The Qinghai-Tibet Plateau (QTP), possesses a climate as cold as that of the Arctic, and also presents uniquely low oxygen concentrations and intense ultraviolet (UV) radiation. QTP animals have adapted to these extreme conditions, but whether they obtained genetic variations from the Arctic during cold adaptation, and how genomic mutations in non-coding regions regulate gene expression under hypoxia and intense UV environment, remain largely unknown. Here, we assemble a high-quality saker falcon genome and resequence populations across Eurasia. We identify female-biased hybridization with Arctic gyrfalcons in the last glacial maximum, that endowed eastern sakers with alleles conveying larger body size and changes in fat metabolism, predisposing their QTP cold adaptation. We discover that QTP hypoxia and UV adaptations mainly involve independent changes in non-coding genomic variants. Our study highlights key roles of gene flow from Arctic relatives during QTP hypothermia adaptation,...
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Papers by Vasiliy Sokolov