scholarly journals Effects of demanding foraging conditions on cache retrieval accuracy in food-caching mountain chickadees ( Poecile gambeli )

2001 ◽  
Vol 268 (1465) ◽  
pp. 363-368 ◽  
Author(s):  
Vladimir V. Pravosudov ◽  
Nicola S. Clayton
2017 ◽  
Vol 123 ◽  
pp. 139-149 ◽  
Author(s):  
Rebecca Croston ◽  
Carrie L. Branch ◽  
Angela M. Pitera ◽  
Dovid Y. Kozlovsky ◽  
Eli S. Bridge ◽  
...  

The Condor ◽  
2005 ◽  
Vol 107 (1) ◽  
pp. 151-155 ◽  
Author(s):  
Sheldon J. Cooper ◽  
James A. Gessaman

AbstractWe measured body temperature of Mountain Chickadees (Poecile gambeli) and Juniper Titmice (Baeolophus ridgwayi) at different times of day and under a range of ambient temperatures in order to determine the use of nocturnal hypothermia in seasonally acclimatized small passerines. Our findings show both species used nocturnal hypothermia year-round. Depth of hypothermia was inversely correlated to body mass in Juniper Titmice but not in Mountain Chickadees. In both species, depth of hypothermia did not vary seasonally but nocturnal body temperature was regulated 3–11°C lower than daytime values. Nocturnal energy savings range from 7%–50% in chickadees and from 10%–28% in titmice. These nocturnal energy savings translate into ecologically important reductions in daily energy expenditures for these two species.Hipotermia Nocturna en Individuos de Poecile gambeli y Baeolophus ridgwayi Aclimatados EstacionalmenteResumen. Medimos la temperatura corporal de Poecile gambeli y Baeolophus ridgwayi a diferentes horas del día y en un rango de temperaturas ambientales para determinar el uso de hipotermia nocturna en pequeñas aves paserinas aclimatadas estacionalmente. Nuestros resultados muestran que ambas especies presentaron hipotermia nocturna durante todo el año. La profundidad de la hipotermia estuvo inversamente correlacionada con la masa corporal en B. ridgwayi, pero no en P. gambeli. En ambas especies, la profundidad de la hipotermia no varió estacionalmente, pero la temperatura corporal nocturna estuvo regulada 3–11°C por debajo de los valores diurnos. El ahorro nocturno de energía varió entre 7%–50% en P. gambeli y entre 10%–28% en B. ridgwayi. Estos ahorros nocturnos de energía se tradujeron en reducciones ecológicamente importantes en los gastos diarios de energía para ambas especies.


The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 635-644 ◽  
Author(s):  
Sheldon J. Cooper

Abstract I used behavioral, meteorological, and laboratory metabolism data to calculate daily energy expenditure (DEE) in seasonally acclimatized Mountain Chickadees (Poecile gambeli) and Juniper Titmice (Baeolophus griseus). Analyses of laboratory metabolic data revealed that foraging energy requirements were not significantly higher than alert perching energy requirements. Respective DEE of chickadees and titmice were 48.8 kJ day−1 and 48.3 kJ day−1 in summer and 66.3 kJ day−1 and 98.7 kJ day−1 in winter. DEE as a multiple of basal metabolic rate (BMR) was 2.31 in summer chickadees and 1.91 in summer titmice. DEE was 2.70 times BMR in winter chickadees and 3.43 times BMR in winter titmice. The marked increase in calculated DEE in winter birds compared to summer is in contrast to a pattern of increased DEE in the breeding season for several avian species. These data suggest that winter may be a period of even greater stringency for small birds than previously believed.


2001 ◽  
Vol 123 (3) ◽  
pp. 324-331 ◽  
Author(s):  
Vladimir V. Pravosudov ◽  
Alexander S. Kitaysky ◽  
John C. Wingfield ◽  
Nicola S. Clayton

2015 ◽  
Vol 2 (4) ◽  
pp. 150019 ◽  
Author(s):  
Carrie L. Branch ◽  
Vladimir V. Pravosudov

Song in songbirds is widely thought to function in mate choice and male–male competition. Song is also phenotypically plastic and typically learned from local adults; therefore, it varies across geographical space and can serve as a cue for an individual's location of origin, with females commonly preferring males from their respective location. Geographical variation in song dialect may reflect acoustic adaptation to different environments and/or serve as a signal of local adaptation. In montane environments, environmental differences can occur over an elevation gradient, favouring local adaptations across small spatial scales. We tested whether food caching mountain chickadees, known to exhibit elevation-related differences in food caching intensity, spatial memory and the hippocampus, also sing different dialects despite continuous distribution and close proximity. Male songs were collected from high and low elevations at two different mountains (separated by 35 km) to test whether song differs between elevations and/or between adjacent populations at each mountain. Song structure varied significantly between high and low elevation adjacent populations from the same mountain and between populations from different mountains at the same elevations, despite a continuous distribution across each mountain slope. These results suggest that elevation-related differences in song structure in chickadees might serve as a signal for local adaptation.


2009 ◽  
Vol 277 (1684) ◽  
pp. 1071-1079 ◽  
Author(s):  
Lara D. LaDage ◽  
Timothy C. Roth ◽  
Rebecca A. Fox ◽  
Vladimir V. Pravosudov

The adult hippocampus in birds and mammals undergoes neurogenesis and the resulting new neurons appear to integrate structurally and functionally into the existing neural architecture. However, the factors underlying the regulation of new neuron production is still under scrutiny. In recent years, the concept that spatial memory affects adult hippocampal neurogenesis has gained acceptance, although results attempting to causally link memory use to neurogenesis remain inconclusive, possibly owing to confounds of motor activity, task difficulty or training for the task. Here, we show that ecologically relevant, spatial memory-based experiences of food caching and retrieving directly affect hippocampal neurogenesis in mountain chickadees ( Poecile gambeli ). We found that restricting memory experiences in captivity caused significantly lower rates of neurogenesis, as determined by doublecortin expression, compared with captive individuals provided with such experiences. However, neurogenesis rates in both groups of captive birds were still greatly lower than those in free-ranging conspecifics. These findings show that ecologically relevant spatial memory experiences can directly modulate neurogenesis, separate from other confounds that may also independently affect neurogenesis.


Sign in / Sign up

Export Citation Format

Share Document