2013
Catenazzi, Alessandro; Kupferberg, Sarah J.
The importance of thermal conditions to recruitment success in stream-breeding frog populations distributed across a productivity gradient Journal Article
In: Biological Conservation, vol. 168, pp. 40-48, 2013.
Abstract | Links | BibTeX | Tags: amphibian declines, Angelo Reserve, California, climate change, Thermoregulation
@article{Catenazzi2013,
title = {The importance of thermal conditions to recruitment success in stream-breeding frog populations distributed across a productivity gradient},
author = {Alessandro Catenazzi and Sarah J. Kupferberg},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Catenazzi_2013_BioConser.pdf},
doi = {10.1016/j.biocon.2013.09.010},
year = {2013},
date = {2013-12-01},
journal = {Biological Conservation},
volume = {168},
pages = {40-48},
abstract = {Predicting the vulnerability of species to environmental change requires integrating observations of individual ecophysiological and behavioral responses with community level constraints. To assess the response of stream-breeding frogs (Rana boylii) to thermal stressors, such as cold water released from the depths of upstream reservoirs or warm water that results from climate change, we combined field manipulations with population censuses and environmental correlations. These frogs migrate between shaded tributaries and open canopy mainstem channels to oviposit where algal food is abundant for tadpoles. Within this context of spatial variation in aquatic primary productivity, we evaluated whether tadpole thermoregulatory behavior is a useful indicator of survival to metamorphosis and adult distribution. In a thermal gradient, tadpoles selected temperatures between 16.5–22.2 °C (mean, 19.60 ± 0.6 °C). We reared tadpoles in streams colder, warmer, or close to thermal preference. Temperature effects were mediated through algal quantity and quality. Mortality increased with increasing deviation from preferred temperatures, but the effects were ameliorated when tadpole diet was supplemented with algae (Cladophora glomerata with epiphytic nitrogen-rich diatoms, Epithemia spp.) harvested from sun-lit channels. Distribution of frogs in free-flowing and dammed reaches within a northern California watershed was in equilibrium with tadpole thermal preference. Populations were dense (⩾125 breeding females/km) where July water temperatures averaged 17.5–19 °C in 2010, a relatively cool summer. Below 16 °C, frogs were sparse with open canopy and absent under closed canopy. Integration of thermoregulatory behavior with ecological context can thus be useful to forecast recruitment when the thermal regimes of rivers are altered by anthropogenic factors.},
keywords = {amphibian declines, Angelo Reserve, California, climate change, Thermoregulation},
pubstate = {published},
tppubtype = {article}
}
Predicting the vulnerability of species to environmental change requires integrating observations of individual ecophysiological and behavioral responses with community level constraints. To assess the response of stream-breeding frogs (Rana boylii) to thermal stressors, such as cold water released from the depths of upstream reservoirs or warm water that results from climate change, we combined field manipulations with population censuses and environmental correlations. These frogs migrate between shaded tributaries and open canopy mainstem channels to oviposit where algal food is abundant for tadpoles. Within this context of spatial variation in aquatic primary productivity, we evaluated whether tadpole thermoregulatory behavior is a useful indicator of survival to metamorphosis and adult distribution. In a thermal gradient, tadpoles selected temperatures between 16.5–22.2 °C (mean, 19.60 ± 0.6 °C). We reared tadpoles in streams colder, warmer, or close to thermal preference. Temperature effects were mediated through algal quantity and quality. Mortality increased with increasing deviation from preferred temperatures, but the effects were ameliorated when tadpole diet was supplemented with algae (Cladophora glomerata with epiphytic nitrogen-rich diatoms, Epithemia spp.) harvested from sun-lit channels. Distribution of frogs in free-flowing and dammed reaches within a northern California watershed was in equilibrium with tadpole thermal preference. Populations were dense (⩾125 breeding females/km) where July water temperatures averaged 17.5–19 °C in 2010, a relatively cool summer. Below 16 °C, frogs were sparse with open canopy and absent under closed canopy. Integration of thermoregulatory behavior with ecological context can thus be useful to forecast recruitment when the thermal regimes of rivers are altered by anthropogenic factors.
2003
Sabo, John L.
Hot rocks or no hot rocks: overnight retreat availability and selection by a diurnal lizard Journal Article
In: Oecologia, vol. 136, no. 3, pp. 329-335, 2003.
Abstract | Links | BibTeX | Tags: Habitat selection, Retreat site, Riparian, Sceloporus occidentalis, Thermoregulation
@article{Sabo2003,
title = {Hot rocks or no hot rocks: overnight retreat availability and selection by a diurnal lizard},
author = {John L. Sabo},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Hot-Rocks-or-No-Hot-Rocks-Overnight-Retreat-Availability-and-Selection-by-a-Diurnal-Lizard_Sabo_2003.pdf},
doi = {10. 1007/s00442-003-1292-6},
year = {2003},
date = {2003-08-00},
journal = {Oecologia},
volume = {136},
number = {3},
pages = {329-335},
abstract = {I used radio telemetry to determine the effects of substrate size and composition on overnight retreat site selection by western fence lizards (Sceloporus occidentalis). In watersheds of northern California (USA), these lizards occupy two habitat types differing in substrate characteristics: rocky cobble bars found in the dry, active channels of rivers and grassy upland meadows. Rocky substrates, found almost exclusively on cobble bars, provided warmer potential retreat sites than all available retreat sites on meadows during the first 5 h of inactivity. Only cobble and sand substrates provided retreats with temperatures within the preferred daily active range (32-36°C) during the inactive period for these lizards (1900-0900 hours). Females on a cobble bar used rocks as retreats on >90% of nights during the breeding season whereas females on a meadow used wood (>70% of nights) and burrows (>25% of nights). In contrast to females, cobble bar males used rocks significantly less frequently (<70%) and slept in the open air significantly more frequently (25% vs. <1%). Cobble bar females further, showed a significant preference for cobbles 15 cm thick, whereas the rocks used by males did not differ significantly in thickness from those measured in randomly placed transects. Rocks 15 cm thick were the warmest retreats commonly available on this habitat type. Thus, thermal microenvironments available to and chosen by gravid female lizards differ considerably between river and non-river habitats.},
keywords = {Habitat selection, Retreat site, Riparian, Sceloporus occidentalis, Thermoregulation},
pubstate = {published},
tppubtype = {article}
}
I used radio telemetry to determine the effects of substrate size and composition on overnight retreat site selection by western fence lizards (Sceloporus occidentalis). In watersheds of northern California (USA), these lizards occupy two habitat types differing in substrate characteristics: rocky cobble bars found in the dry, active channels of rivers and grassy upland meadows. Rocky substrates, found almost exclusively on cobble bars, provided warmer potential retreat sites than all available retreat sites on meadows during the first 5 h of inactivity. Only cobble and sand substrates provided retreats with temperatures within the preferred daily active range (32-36°C) during the inactive period for these lizards (1900-0900 hours). Females on a cobble bar used rocks as retreats on >90% of nights during the breeding season whereas females on a meadow used wood (>70% of nights) and burrows (>25% of nights). In contrast to females, cobble bar males used rocks significantly less frequently (<70%) and slept in the open air significantly more frequently (25% vs. <1%). Cobble bar females further, showed a significant preference for cobbles 15 cm thick, whereas the rocks used by males did not differ significantly in thickness from those measured in randomly placed transects. Rocks 15 cm thick were the warmest retreats commonly available on this habitat type. Thus, thermal microenvironments available to and chosen by gravid female lizards differ considerably between river and non-river habitats.
1978
Barrows, Cameron; Balderston, Katherine
Roost Characteristics and Behavioral Thermoregulation in the Spotted Owl Journal Article
In: Western Birds, vol. 9, no. 1, 1978.
Abstract | Links | BibTeX | Tags: spotted owl, Thermoregulation
@article{Barrows1978,
title = {Roost Characteristics and Behavioral Thermoregulation in the Spotted Owl},
author = {Cameron Barrows and Katherine Balderston},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Barrows_WesternBirds1978.pdf},
year = {1978},
date = {1978-01-01},
urldate = {1978-00-00},
journal = {Western Birds},
volume = {9},
number = {1},
abstract = {Previous studies on the Spotted Owl (Strix occidentalis) have established
important parameters in habitat preference of this species. Old growth, multi-layered forests;water availability;and the presence of suitable nest sites are consistent characteristics of the habitats occupied (Gould 1974, 1977; Forsman 1976). These authors postulated heat intolerance as a possible factor in habitat selection. To further examine this hypothesis, we analyzed aspects of Spotted Owl habitat in preferred use areas, particularly at major roost sites, and related this information to behavioral adaptations of the owls. This preliminary investigation was aimed specifically at understanding features of the forest environment which determine roost site selection. Relating to these features, possible limitations imposed on the Spotted Owl by physiological tolerances to environmental extremes were also considered},
keywords = {spotted owl, Thermoregulation},
pubstate = {published},
tppubtype = {article}
}
Previous studies on the Spotted Owl (Strix occidentalis) have established
important parameters in habitat preference of this species. Old growth, multi-layered forests;water availability;and the presence of suitable nest sites are consistent characteristics of the habitats occupied (Gould 1974, 1977; Forsman 1976). These authors postulated heat intolerance as a possible factor in habitat selection. To further examine this hypothesis, we analyzed aspects of Spotted Owl habitat in preferred use areas, particularly at major roost sites, and related this information to behavioral adaptations of the owls. This preliminary investigation was aimed specifically at understanding features of the forest environment which determine roost site selection. Relating to these features, possible limitations imposed on the Spotted Owl by physiological tolerances to environmental extremes were also considered
important parameters in habitat preference of this species. Old growth, multi-layered forests;water availability;and the presence of suitable nest sites are consistent characteristics of the habitats occupied (Gould 1974, 1977; Forsman 1976). These authors postulated heat intolerance as a possible factor in habitat selection. To further examine this hypothesis, we analyzed aspects of Spotted Owl habitat in preferred use areas, particularly at major roost sites, and related this information to behavioral adaptations of the owls. This preliminary investigation was aimed specifically at understanding features of the forest environment which determine roost site selection. Relating to these features, possible limitations imposed on the Spotted Owl by physiological tolerances to environmental extremes were also considered