Pub Date : 2026-03-01Epub Date: 2026-01-07DOI: 10.1016/j.beproc.2025.105325
Amir Tarizadeh, Marjan Seiedy
Male genital and non-genital structures that are specialized to contact the female during copulation have diverged rapidly in many animal taxa. Three hypotheses that provide different explanations for this trend are reproductive isolation, sexual conflict, and female choice. We tested these hypotheses in sepsid flies, which have been considered case studies of sexual conflict, as males grasp and hold the females’ wings with their species-specific front legs before and during mating, and females seem to actively resist this hold. The reproductive isolation and the sexual conflict hypotheses predict that the species-specific modifications of the male’s front legs function as devices to mechanically improve their hold on the female’s wings. The female choice hypothesis predicts that the male front legs function as stimulatory courtship devices. We tested these predictions by observing mating interactions, morphological contact, and the distribution of female sense organs in two species, Sepsis barbata and S. thoracica. Male front legs performed rhythmic, stereotypic, and species-specific movements, providing tactile stimulation of zones of the female wing that contained numerous sense organs but not improving their mechanical grip. We conclude that male front legs are stimulation devices rather than species-specific mechanical clamps, supporting the female choice hypothesis.
{"title":"The front legs of Sepsis flies (Diptera: Sepsidae) are stimulation devices","authors":"Amir Tarizadeh, Marjan Seiedy","doi":"10.1016/j.beproc.2025.105325","DOIUrl":"10.1016/j.beproc.2025.105325","url":null,"abstract":"<div><div>Male genital and non-genital structures that are specialized to contact the female during copulation have diverged rapidly in many animal taxa. Three hypotheses that provide different explanations for this trend are reproductive isolation, sexual conflict, and female choice. We tested these hypotheses in sepsid flies, which have been considered case studies of sexual conflict, as males grasp and hold the females’ wings with their species-specific front legs before and during mating, and females seem to actively resist this hold. The reproductive isolation and the sexual conflict hypotheses predict that the species-specific modifications of the male’s front legs function as devices to mechanically improve their hold on the female’s wings. The female choice hypothesis predicts that the male front legs function as stimulatory courtship devices. We tested these predictions by observing mating interactions, morphological contact, and the distribution of female sense organs in two species, <em>Sepsis barbata</em> and <em>S. thoracica</em>. Male front legs performed rhythmic, stereotypic, and species-specific movements, providing tactile stimulation of zones of the female wing that contained numerous sense organs but not improving their mechanical grip. We conclude that male front legs are stimulation devices rather than species-specific mechanical clamps, supporting the female choice hypothesis.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"236 ","pages":"Article 105325"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145942432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-01-17DOI: 10.1016/j.beproc.2026.105341
Kyle M. Roddick , Paige A. Northrup , Heather M. Schellinck , Richard E. Brown
The McGill-R-Thy1-APP rat is a transgenic model of Alzheimer’s disease (AD) which expresses APP with two mutations found in cases of familial AD, resulting in the development of amyloid pathology and cognitive deficits. Motor deficits are common symptoms of AD, emerging early in the disease, and are correlated with AD neuropathology and cognitive symptoms. This study evaluated hemizygous and homozygous McGill-R-Thy1-APP rats and their wildtype littermates for spontaneous alternation and locomotion in the T and Y mazes, and motor behaviour on an accelerating rotarod at 12–13 months of age. We found no genotype or sex effects in spontaneous alternation in either maze, nor a significant correlation of spontaneous alternation behaviour between the mazes. Female rats travelled greater distances than male rats in both mazes. While there was no genotype effect in the T maze on distance travelled, in the Y maze the hemizygous rats travelled shorter distances than the wildtype rats, while the homozygous rats travelled greater distances. There was a significant correlation between the distances travelled in each maze. Both hemizygous and homozygous rats performed worse than their wildtype littermates on the rotarod, while heavier rats performed worse than lighter rats, and female rats performed worse than male rats once their differences in weights were accounted for. These findings support the continued use of these rats as a model of AD and highlight the need to consider the possible confounding effect motor impairments have on other behavioural tests.
{"title":"Motor deficits in the McGill-R-Thy1-APP transgenic rat model of Alzheimer’s disease","authors":"Kyle M. Roddick , Paige A. Northrup , Heather M. Schellinck , Richard E. Brown","doi":"10.1016/j.beproc.2026.105341","DOIUrl":"10.1016/j.beproc.2026.105341","url":null,"abstract":"<div><div>The McGill-R-Thy1-APP rat is a transgenic model of Alzheimer’s disease (AD) which expresses APP with two mutations found in cases of familial AD, resulting in the development of amyloid pathology and cognitive deficits. Motor deficits are common symptoms of AD, emerging early in the disease, and are correlated with AD neuropathology and cognitive symptoms. This study evaluated hemizygous and homozygous McGill-R-Thy1-APP rats and their wildtype littermates for spontaneous alternation and locomotion in the T and Y mazes, and motor behaviour on an accelerating rotarod at 12–13 months of age. We found no genotype or sex effects in spontaneous alternation in either maze, nor a significant correlation of spontaneous alternation behaviour between the mazes. Female rats travelled greater distances than male rats in both mazes. While there was no genotype effect in the T maze on distance travelled, in the Y maze the hemizygous rats travelled shorter distances than the wildtype rats, while the homozygous rats travelled greater distances. There was a significant correlation between the distances travelled in each maze. Both hemizygous and homozygous rats performed worse than their wildtype littermates on the rotarod, while heavier rats performed worse than lighter rats, and female rats performed worse than male rats once their differences in weights were accounted for. These findings support the continued use of these rats as a model of AD and highlight the need to consider the possible confounding effect motor impairments have on other behavioural tests.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"236 ","pages":"Article 105341"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146002993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-05DOI: 10.1016/j.beproc.2026.105329
L. Lacuesta, R. Ungerfeld
The objectives were to determine whether, in a group of adult rams: 1) the dominance index (DI) differs when calculated using absolute vs relative values using different approaches (competition for food (F), estrous females (EF) or recording of spontaneous agonistic interaction (AI)), 2) there is a consistent relationship between DI values calculated using absolute values when rams compete for F, for an EF or display spontaneous AI, and 3) there is concordance between individual hierarchical positions calculated from results of F, EF competition tests, or spontaneous AI. Twelve rams were used, and the DI was calculated using three methods: competition for food, competition for an estrous female, and spontaneous AI, in all cases assigning absolute or relative values. There was a positive correlation between the individual DI values calculated from absolute and relative measures using the food competition test, estrous female, or spontaneous AI. There was no correlation between the individual DI values obtained from the F and the EF competition tests, or from spontaneous AI. There was a positive concordance between individual hierarchical positions calculated from the F and EF competitions and those obtained using spontaneous AI. Although different methods provided differences on individual DI, the assigned value did not successfully predict the hierarchical position.
{"title":"Social hierarchy determination in rams: A comparison of different methods","authors":"L. Lacuesta, R. Ungerfeld","doi":"10.1016/j.beproc.2026.105329","DOIUrl":"10.1016/j.beproc.2026.105329","url":null,"abstract":"<div><div>The objectives were to determine whether, in a group of adult rams: 1) the dominance index (DI) differs when calculated using absolute vs relative values using different approaches (competition for food (F), estrous females (EF) or recording of spontaneous agonistic interaction (AI)), 2) there is a consistent relationship between DI values calculated using absolute values when rams compete for F, for an EF or display spontaneous AI, and 3) there is concordance between individual hierarchical positions calculated from results of F, EF competition tests, or spontaneous AI. Twelve rams were used, and the DI was calculated using three methods: competition for food, competition for an estrous female, and spontaneous AI, in all cases assigning absolute or relative values. There was a positive correlation between the individual DI values calculated from absolute and relative measures using the food competition test, estrous female, or spontaneous AI. There was no correlation between the individual DI values obtained from the F and the EF competition tests, or from spontaneous AI. There was a positive concordance between individual hierarchical positions calculated from the F and EF competitions and those obtained using spontaneous AI. Although different methods provided differences on individual DI, the assigned value did not successfully predict the hierarchical position.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105329"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145916907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-30DOI: 10.1016/j.beproc.2025.105326
Francisco Javier Zamora-Camacho
Animals are expected to adjust their decisions to different contexts so that their benefits outweigh the costs. For instance, the proximity of predators frequently leads to cautious behaviors, whereas competitors promote boldness. Foraging can be affected by these patterns, although to an extent that may depend on the individual’s need for food. In this work, I investigate the effect of chemical cues of non-gape-limited predators and intraspecific competitors on foraging rates of Iberian spadefoot toad (Pelobates cultripes) tadpoles either fed ad libitum or fasted for 24 h. Food restriction did not affect foraging rates, and neither did predator cues. These are large tadpoles that could have enough reserves to survive a 24-hour fast, and be difficult to handle by most predators. However, tadpoles ate more in the presence of competitor cues. Hoarding food under dispute could maximize its consumption before the competitor reduces the amount of it available, also limiting the access of the competitor to it, probably limiting its growth and its ability to compete in future encounters.
{"title":"I call dibs on it! Chemical cues of intraspecific competitors potentiate food consumption in anuran tadpoles","authors":"Francisco Javier Zamora-Camacho","doi":"10.1016/j.beproc.2025.105326","DOIUrl":"10.1016/j.beproc.2025.105326","url":null,"abstract":"<div><div>Animals are expected to adjust their decisions to different contexts so that their benefits outweigh the costs. For instance, the proximity of predators frequently leads to cautious behaviors, whereas competitors promote boldness. Foraging can be affected by these patterns, although to an extent that may depend on the individual’s need for food. In this work, I investigate the effect of chemical cues of non-gape-limited predators and intraspecific competitors on foraging rates of Iberian spadefoot toad (<em>Pelobates cultripes</em>) tadpoles either fed <em>ad libitum</em> or fasted for 24 h. Food restriction did not affect foraging rates, and neither did predator cues. These are large tadpoles that could have enough reserves to survive a 24-hour fast, and be difficult to handle by most predators. However, tadpoles ate more in the presence of competitor cues. Hoarding food under dispute could maximize its consumption before the competitor reduces the amount of it available, also limiting the access of the competitor to it, probably limiting its growth and its ability to compete in future encounters.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105326"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-29DOI: 10.1016/j.beproc.2025.105324
Rui Han , Jun Zhang , Xin-Hui Chen , Jing-Wen Duo , Yi-Yi Li , Yi-Ran Chen , Si-Tong Chen , Lin-Xiang Liu , Xiang-Haoran Lin
Mating behaviour plays a key role in animal reproduction and profoundly affects the physiological state and behavioural performance of individuals. Although numerous studies have focused on the behavioural responses of single-sex groups of Drosophila melanogaster under mating contexts, systematic comparisons of male and female fruit flies across different mating contexts are still relatively limited. This study investigated the locomotion of 86 male and female fruit flies under different mating contexts, including virgin, continuously exposed to the opposite sex (mated), beginning cohabitation with the opposite sex on the 8th day of the experiment (virgin-mated), and opposite-sex cohabitation on the 8th day and switching to same-sex cohabitation (mated-deprived). The results showed that virgin males exhibited the highest overall movement speed and that continuous exposure to the opposite sex led to a transient reduction in male movement speed. In contrast, females displayed a temporary increase in movement speed under opposite-sex cohabitation but rapidly returned to levels comparable to virgins. These sex-specific and time-dependent changes indicate that mating context exerts dynamic effects on movement speed. Moreover, in contrast to the negative effects of social isolation reported in previous studies, our findings suggest that mating status and social environment jointly shape locomotor performance under non-isolated conditions. Overall, this study highlights how males and females dynamically adjust locomotor strategies in response to changing reproductive and social contexts, providing an evolutionary perspective on behavioural plasticity and sex-specific trade-offs in insects.
{"title":"Sex differences in locomotor recovery across mating contexts in Drosophila melanogaster","authors":"Rui Han , Jun Zhang , Xin-Hui Chen , Jing-Wen Duo , Yi-Yi Li , Yi-Ran Chen , Si-Tong Chen , Lin-Xiang Liu , Xiang-Haoran Lin","doi":"10.1016/j.beproc.2025.105324","DOIUrl":"10.1016/j.beproc.2025.105324","url":null,"abstract":"<div><div>Mating behaviour plays a key role in animal reproduction and profoundly affects the physiological state and behavioural performance of individuals. Although numerous studies have focused on the behavioural responses of single-sex groups of <em>Drosophila melanogaster</em> under mating contexts, systematic comparisons of male and female fruit flies across different mating contexts are still relatively limited. This study investigated the locomotion of 86 male and female fruit flies under different mating contexts, including virgin, continuously exposed to the opposite sex (mated), beginning cohabitation with the opposite sex on the 8th day of the experiment (virgin-mated), and opposite-sex cohabitation on the 8th day and switching to same-sex cohabitation (mated-deprived). The results showed that virgin males exhibited the highest overall movement speed and that continuous exposure to the opposite sex led to a transient reduction in male movement speed. In contrast, females displayed a temporary increase in movement speed under opposite-sex cohabitation but rapidly returned to levels comparable to virgins. These sex-specific and time-dependent changes indicate that mating context exerts dynamic effects on movement speed. Moreover, in contrast to the negative effects of social isolation reported in previous studies, our findings suggest that mating status and social environment jointly shape locomotor performance under non-isolated conditions. Overall, this study highlights how males and females dynamically adjust locomotor strategies in response to changing reproductive and social contexts, providing an evolutionary perspective on behavioural plasticity and sex-specific trade-offs in insects.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105324"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145877629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-02DOI: 10.1016/j.beproc.2026.105327
Gerson Yukio Tomanari
Food-deprived pigeons were given a random sequence of 50-s discrete trials, half of which ended with and half without response-independent food presentation. During a trial, pecking a white key could change its color to red or green, depending on whether food (S+ color) or no food (S- color) was scheduled. In the single stimulus-production condition (SSP), if the red or the green key color was produced, the key remained red or green, respectively, until the end of the trial. In the multiple stimulus-production condition (MSP), the duration of each green or red illumination was limited to a maximum of 10 s. After 10 s, the white light resumed and additional key-color changes (re-presentations of S+ or S-) were possible. Results showed that S+ and S- were produced equally often in SSP, as well as in the first stimulus production in MSP. The frequencies of S- re-presentations, however, were clearly and systematically higher than the frequencies of S+ re-presentations. These findings demonstrate that under certain conditions, a stimulus signaling the absence of primary reinforcement (S-) can maintain higher rates of observing behavior than a stimulus signaling its presence (S+).
{"title":"Observing responses maintained by re-presentations of S-","authors":"Gerson Yukio Tomanari","doi":"10.1016/j.beproc.2026.105327","DOIUrl":"10.1016/j.beproc.2026.105327","url":null,"abstract":"<div><div>Food-deprived pigeons were given a random sequence of 50-s discrete trials, half of which ended with and half without response-independent food presentation. During a trial, pecking a white key could change its color to red or green, depending on whether food (S+ color) or no food (S- color) was scheduled. In the single stimulus-production condition (SSP), if the red or the green key color was produced, the key remained red or green, respectively, until the end of the trial. In the multiple stimulus-production condition (MSP), the duration of each green or red illumination was limited to a maximum of 10 s. After 10 s, the white light resumed and additional key-color changes (re-presentations of S+ or S-) were possible. Results showed that S+ and S- were produced equally often in SSP, as well as in the first stimulus production in MSP. The frequencies of S- re-presentations, however, were clearly and systematically higher than the frequencies of S+ re-presentations. These findings demonstrate that under certain conditions, a stimulus signaling the absence of primary reinforcement (S-) can maintain higher rates of observing behavior than a stimulus signaling its presence (S+).</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105327"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-05DOI: 10.1016/j.beproc.2026.105330
Julian C. Velasquez , Carlos J. Flores
This experiment aimed to extend the use of the timeout-from-avoidance procedure used by Velasquez et al. (2025) to study resurgence of negatively reinforced behavior with rats. In Phase 1, responses on the target timeout lever produced 2 min timeouts from a free-operant avoidance schedule wherein shocks could be postponed by pressing an avoidance lever. In Phase 2, target timeout responding was extinguished, while responses on the alternative timeout lever produced the 2 min timeouts and the avoidance response continued to postpone shocks. Finally, in Phase 3, alternative timeout responding was extinguished while the avoidance schedule remained unchanged. Results showed evidence of resurgence in two of four rats. Although the robust finding of resurgence of negatively reinforced behavior typically reported with humans was not consistently replicated, the present results provide a first approximation in this line of research, highlighting the complexity of translating and implementing negative reinforcement paradigms analogous to their positive reinforcement counterparts.
{"title":"Using a timeout-from-avoidance procedure to explore resurgence of negatively reinforced behavior with rats","authors":"Julian C. Velasquez , Carlos J. Flores","doi":"10.1016/j.beproc.2026.105330","DOIUrl":"10.1016/j.beproc.2026.105330","url":null,"abstract":"<div><div>This experiment aimed to extend the use of the timeout-from-avoidance procedure used by Velasquez et al. (2025) to study resurgence of negatively reinforced behavior with rats. In Phase 1, responses on the target timeout lever produced 2 min timeouts from a free-operant avoidance schedule wherein shocks could be postponed by pressing an avoidance lever. In Phase 2, target timeout responding was extinguished, while responses on the alternative timeout lever produced the 2 min timeouts and the avoidance response continued to postpone shocks. Finally, in Phase 3, alternative timeout responding was extinguished while the avoidance schedule remained unchanged. Results showed evidence of resurgence in two of four rats. Although the robust finding of resurgence of negatively reinforced behavior typically reported with humans was not consistently replicated, the present results provide a first approximation in this line of research, highlighting the complexity of translating and implementing negative reinforcement paradigms analogous to their positive reinforcement counterparts.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105330"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145916890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-23DOI: 10.1016/j.beproc.2025.105323
Chris T. Tromborg, Richard G. Coss, Kenneth R. Henry
California ground squirrels (Otospermophilus becheeyi) exhibit adaptive variation to their local environments based on antipredator, immunological, and social-communication evaluations. The following pair of experiments investigated the acoustic and behavioral responses of California ground squirrels from the higher-elevation Sierra Valley (alt. ∼1900 m) and from the lower-elevation Sunol region (alt. ∼270 m). Analyses of their genetic distance suggest that these populations diverged during the Late Pleistocene. The first experiment compared small groups from these populations on the basis of their auditory brainstem responses (ABR) to a range of sound frequencies. The ABR audiograms of Sierra Valley squirrels showed greater acoustic sensitivity to frequencies lower than 4 kHz than the Sunol squirrels. Both groups exhibited similar audiograms for higher frequencies. Such an adaptation would be useful for coping with dangerous circumstances possibly masked by inclement weather. The second experiment compared the squirrel groups for several 9-hr observation periods focusing on the number of egress bouts from nest boxes centered in a laboratory room equipped with sound playback equipment to simulate far-field naturalistic sounds. Three sound treatments were compared: 1) ambient room sound, 2) temperate forest, and 3) rainstorm. Analyses indicated that the higher-altitude Sierra Valley squirrels were reliably less likely to leave the nestbox to explore the room than were low-altitude Sunol squirrels under the rain treatment. The results of both studies suggest that the enhanced low-frequency hearing of Sierra Valley squirrels is a sensory adaptation for coping with the reduced sound transmission of low frequencies at higher altitudes.
{"title":"Adaptive variation in the acoustic sensitivity of California ground squirrels (Otospermophilus beecheyi) living in higher- and lower-elevation habitats","authors":"Chris T. Tromborg, Richard G. Coss, Kenneth R. Henry","doi":"10.1016/j.beproc.2025.105323","DOIUrl":"10.1016/j.beproc.2025.105323","url":null,"abstract":"<div><div>California ground squirrels (<em>Otospermophilus becheeyi</em>) exhibit adaptive variation to their local environments based on antipredator, immunological, and social-communication evaluations. The following pair of experiments investigated the acoustic and behavioral responses of California ground squirrels from the higher-elevation Sierra Valley (alt. ∼1900 m) and from the lower-elevation Sunol region (alt. ∼270 m). Analyses of their genetic distance suggest that these populations diverged during the Late Pleistocene. The first experiment compared small groups from these populations on the basis of their auditory brainstem responses (ABR) to a range of sound frequencies. The ABR audiograms of Sierra Valley squirrels showed greater acoustic sensitivity to frequencies lower than 4 kHz than the Sunol squirrels. Both groups exhibited similar audiograms for higher frequencies. Such an adaptation would be useful for coping with dangerous circumstances possibly masked by inclement weather. The second experiment compared the squirrel groups for several 9-hr observation periods focusing on the number of egress bouts from nest boxes centered in a laboratory room equipped with sound playback equipment to simulate far-field naturalistic sounds. Three sound treatments were compared: 1) ambient room sound, 2) temperate forest, and 3) rainstorm. Analyses indicated that the higher-altitude Sierra Valley squirrels were reliably less likely to leave the nestbox to explore the room than were low-altitude Sunol squirrels under the rain treatment. The results of both studies suggest that the enhanced low-frequency hearing of Sierra Valley squirrels is a sensory adaptation for coping with the reduced sound transmission of low frequencies at higher altitudes.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105323"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145833061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-06DOI: 10.1016/j.beproc.2026.105333
Cindy Bessey , Nick Mortimer , Ellie Slatter , Zoe Slatter , Logan Hellmrich , John K. Keesing
Sea cucumbers are large conspicuous invertebrates that play an important functional role in coral reef ecosystems through bioturbation and organic load recycling making their abundance and movement patterns key features to understanding impacts on the benthos. This study examines the diel movement patterns of an unfished population of the commercially important sea cucumber, the deep-water redfish (Actinopyga echinites), within a fully protected marine sanctuary on the Ningaloo Reef, Western Australia. Movement rates were measured using long-run underwater stereo-video, while density was measured using belt transects. The size of A. echinites was also investigated. We observed abundances of A. echinites (1.58 individuals / m2) that far exceeded those from areas with fishing pressures. The majority of A. echinites were in the 150–175 mm size range, with no individuals less than 100 mm recorded. We quantified the movement patterns of 92 individual sea cucumbers which correlated with light intensity throughout a 24-hour period, where maximum mean movement rates occurred at 1:00 pm (75.7 cm / hour) before slowly decreasing with reduced light intensity. Actinopyga echinites specimens were primarily stationary between midnight and 7 am and were stationary and non-feeding approximately 22 % of the time. Most of the time (68 %) A. echinites were classified as non-stationary and feeding and significantly more active during the day. We discuss the abundance and size of A. echinites in relation to studies from other areas and relate their diurnal movement patterns to diel foraging theory.
{"title":"Diurnal patterns of movement and feeding for an unfished population of Actinopyga echinites (Jaeger, 1833) in a protected marine sanctuary on Ningaloo Reef, northwestern Australia","authors":"Cindy Bessey , Nick Mortimer , Ellie Slatter , Zoe Slatter , Logan Hellmrich , John K. Keesing","doi":"10.1016/j.beproc.2026.105333","DOIUrl":"10.1016/j.beproc.2026.105333","url":null,"abstract":"<div><div>Sea cucumbers are large conspicuous invertebrates that play an important functional role in coral reef ecosystems through bioturbation and organic load recycling making their abundance and movement patterns key features to understanding impacts on the benthos. This study examines the diel movement patterns of an unfished population of the commercially important sea cucumber, the deep-water redfish (<em>Actinopyga echinites</em>), within a fully protected marine sanctuary on the Ningaloo Reef, Western Australia. Movement rates were measured using long-run underwater stereo-video, while density was measured using belt transects. The size of <em>A. echinites</em> was also investigated. We observed abundances of <em>A. echinites</em> (1.58 individuals / m<sup>2</sup>) that far exceeded those from areas with fishing pressures. The majority <em>of A. echinites</em> were in the 150–175 mm size range, with no individuals less than 100 mm recorded. We quantified the movement patterns of 92 individual sea cucumbers which correlated with light intensity throughout a 24-hour period, where maximum mean movement rates occurred at 1:00 pm (75.7 cm / hour) before slowly decreasing with reduced light intensity. <em>Actinopyga echinites</em> specimens were primarily stationary between midnight and 7 am and were stationary and non-feeding approximately 22 % of the time. Most of the time (68 %) <em>A. echinites</em> were classified as non-stationary and feeding and significantly more active during the day. We discuss the abundance and size of <em>A. echinites</em> in relation to studies from other areas and relate their diurnal movement patterns to diel foraging theory.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105333"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-11DOI: 10.1016/j.beproc.2025.105321
Fionnghuala L.J. James , Sayed K. Ahamed , Cheng Yang , Jigme Thinley , Carmelo M. Vicario , Juan J. Canales , Sukhwinder S. Sohal , Richard Wilson , Luke R. Johnson , Vanni Caruso
The processes of memory consolidation and reconsolidation are important in understanding the dynamics of memory storage and modification. Models to condition aversive memory have been characterised in rodents yet have been less explored in invertebrates such as planaria. Planaria are a potentially important animal model for the study of threat learning and memory as they can learn conditioned responses and may show conserved neural mechanisms underpinning these responses compared to mammals. However, no model for the study of memory in classical threat conditioning exists for planaria. The aim of this study is to replicate a standardised cued threat conditioning model for memory acquisition and reconsolidation in mice, in brown planaria (Girardia dorotocephala), using shock as the unconditioned stimulus (US) and light as the conditioned stimulus (CS). Defensive behaviours (C-shaped movements and scrunching) were assessed to evaluate learning. Planaria underwent memory acquisition training for a total of 18 learning trials. In the consolidation model, memory retention was tested 24 h after the final training session with a CS exposure. In the reconsolidation model, memory stability was assessed using a recall test 24 h after a reactivation session. In both tests, the paired shock-light group exhibited a significant increase in defensive behaviours, compared to all control groups, suggesting that the pairing of both shock and light was essential for forming a lasting memory. Furthermore, planaria exhibited a gradual extinction of defensive responses to the CS. These findings highlight the utility of planaria for studying associative learning and memory, including memory reconsolidation.
{"title":"Adapting rodent cued threat conditioning to planarians: Memory acquisition, consolidation, and reconsolidation","authors":"Fionnghuala L.J. James , Sayed K. Ahamed , Cheng Yang , Jigme Thinley , Carmelo M. Vicario , Juan J. Canales , Sukhwinder S. Sohal , Richard Wilson , Luke R. Johnson , Vanni Caruso","doi":"10.1016/j.beproc.2025.105321","DOIUrl":"10.1016/j.beproc.2025.105321","url":null,"abstract":"<div><div>The processes of memory consolidation and reconsolidation are important in understanding the dynamics of memory storage and modification. Models to condition aversive memory have been characterised in rodents yet have been less explored in invertebrates such as planaria. Planaria are a potentially important animal model for the study of threat learning and memory as they can learn conditioned responses and may show conserved neural mechanisms underpinning these responses compared to mammals. However, no model for the study of memory in classical threat conditioning exists for planaria. The aim of this study is to replicate a standardised cued threat conditioning model for memory acquisition and reconsolidation in mice, in brown planaria (<em>Girardia dorotocephala</em>), using shock as the unconditioned stimulus (US) and light as the conditioned stimulus (CS). Defensive behaviours (C-shaped movements and scrunching) were assessed to evaluate learning. Planaria underwent memory acquisition training for a total of 18 learning trials. In the consolidation model, memory retention was tested 24 h after the final training session with a CS exposure. In the reconsolidation model, memory stability was assessed using a recall test 24 h after a reactivation session. In both tests, the paired shock-light group exhibited a significant increase in defensive behaviours, compared to all control groups, suggesting that the pairing of both shock and light was essential for forming a lasting memory. Furthermore, planaria exhibited a gradual extinction of defensive responses to the CS. These findings highlight the utility of planaria for studying associative learning and memory, including memory reconsolidation.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105321"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145751461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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