Remote sensing image segmentation is the basis of image understanding and analysis. However,the precision and the speed of segmentation can not meet the need of image analysis,due to strong uncertainty and rich textur...Remote sensing image segmentation is the basis of image understanding and analysis. However,the precision and the speed of segmentation can not meet the need of image analysis,due to strong uncertainty and rich texture details of remote sensing images. We proposed a new segmentation method based on Adaptive Genetic Algorithm(AGA) and Alternative Fuzzy C-Means(AFCM) . Segmentation thresholds were identified by AGA. Then the image was segmented by AFCM. The results indicate that the precision and the speed of segmentation have been greatly increased,and the accuracy of threshold selection is much higher compared with traditional Otsu and Fuzzy C-Means(FCM) segmentation methods. The segmentation results also show that multi-thresholds segmentation has been achieved by combining AGA with AFCM.展开更多
Multimodal communication in animals is common,and is particularly well studied in signals that include both visual and auditory components.Multimodal signals that combine acoustic and olfactory components are less wel...Multimodal communication in animals is common,and is particularly well studied in signals that include both visual and auditory components.Multimodal signals that combine acoustic and olfactory components are less well known.Multimodal communication plays a crucial role in agonistic interactions in many mammals,but relatively little is known about this type of communication in nocturnal mammals.Here,we used male Great Himalayan leaf-nosed bats Hipposideros armiger to investigate multimodal signal function in acoustic and olfactory aggressive displays.We monitored the physiological responses(heart rate[HR])when H.armiger was presented with 1 of 3 stimuli:territorial calls,forehead gland odors,and bimodal signals(calls+odors).Results showed that H.armiger rapidly increased their HR when exposed to any of the 3 stimuli.However,the duration of elevated HR and magnitude of change in HR increased significantly more when acoustic stimuli were presented alone compared with the presentation of olfactory stimuli alone.In contrast,the duration of elevated HR and magnitude of change in HR were significantly higher with bimodal stimuli than with olfactory stimuli alone,but no significant differences were found between the HR response to acoustic and bimodal stimuli.Our previous work showed that acoustic and chemical signals provided different types of information;here we describe experiments investigating the responses to those signals.These results suggest that olfactory and acoustic signals are non-redundant signal components,and that the acoustic component is the dominant modality in male H.armiger,at least as it related to HR.This study provides the first evidence that acoustic signals dominate over olfactory signals during agonistic interactions in a nocturnal mammal.展开更多
Anti-predation strategies are critical to animal survival and are fundamental to deciphering predator–prey interactions.As an important defense strategy,sensory predator detection(such as through acoustic and visual ...Anti-predation strategies are critical to animal survival and are fundamental to deciphering predator–prey interactions.As an important defense strategy,sensory predator detection(such as through acoustic and visual cues)enables animals to assess predation risk and execute predator-avoidance behavior;however,there are limited studies on the anti-predation behavior of nocturnal animals.The prey of bats provides an excellent representative system for examining the anti-predation behavior of nocturnal animals.Here,we broadcasted different types of echolocation calls of the bird-eating bat Ia io to two wild passerine birds,namely,Zosterops japonicus and Sinosuthora webbiana,that are preyed upon by I.io,and presented the birds with individual bats under different light intensities.The results showed that both bird species were able to perceive the low-frequency audible portion of the bats’echolocation calls;however,they did not exhibit escape responses to the acoustic stimuli.In the dark and under moonlit conditions,both bird species were unable to respond to active bats at close range and the birds only exhibited evasive flight behavior when bats approached or touched them.These results suggest that nocturnal passerine birds may not be able to use acoustic or visual cues to detect bats and adopt evasive maneuvers to avoid predation.This work suggests that bat predation pressure may not elicit primary predator-avoidance responses in nocturnal passerine birds.The results provide new insights into the anti-predation behavior of nocturnal animals.展开更多
Signals containing parameter trade-offs are likely to be honest indicators of signaler quality because they are difficult to produce.Signals with a trill-rate/bandwidth trade-off have been described for many songbird s...Signals containing parameter trade-offs are likely to be honest indicators of signaler quality because they are difficult to produce.Signals with a trill-rate/bandwidth trade-off have been described for many songbird species,one mouse,and one non-human primate species.However,there were no reports about whether there is a vocal performance trade-off in social calls of bats.This study investigated(1)a possible vocal performance trade-off in territorial calls of male Great Himalayan leaf-nosed bats,Hipposideros armiger,recorded from 9 locations in south China,and(2)the relationships between vocal performance(vocal deviation and consistency)and caller’s quality(body mass)to determine whether vocal performance honestly indicates a caller’s quality.Vocal deviation measures the deviation of a call relative to an extreme call and vocal consistency measures the spectral consistency across a string of syllables.Our results showed a significant negative correlation between syllable repetition rate and frequency bandwidth,suggesting a vocal performance trade-off similar to the one in songbirds.Further,there was a significant negative relationship between body mass and vocal deviation,but no significant correlation between body mass and vocal consistency.This study provides thefirst empirical evidence for a vocal performance trade-off of social calls in bats,and the potential for the level of performance to indicate caller quality.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 30370267)Key Project of Jilin Provincial Science & Technology Department (No. 20075014)
文摘Remote sensing image segmentation is the basis of image understanding and analysis. However,the precision and the speed of segmentation can not meet the need of image analysis,due to strong uncertainty and rich texture details of remote sensing images. We proposed a new segmentation method based on Adaptive Genetic Algorithm(AGA) and Alternative Fuzzy C-Means(AFCM) . Segmentation thresholds were identified by AGA. Then the image was segmented by AFCM. The results indicate that the precision and the speed of segmentation have been greatly increased,and the accuracy of threshold selection is much higher compared with traditional Otsu and Fuzzy C-Means(FCM) segmentation methods. The segmentation results also show that multi-thresholds segmentation has been achieved by combining AGA with AFCM.
基金the National Natural Science Foundation of China(Grant Nos.31872680,31922050)the Program for Introducing Talents to Universities(B16011).
文摘Multimodal communication in animals is common,and is particularly well studied in signals that include both visual and auditory components.Multimodal signals that combine acoustic and olfactory components are less well known.Multimodal communication plays a crucial role in agonistic interactions in many mammals,but relatively little is known about this type of communication in nocturnal mammals.Here,we used male Great Himalayan leaf-nosed bats Hipposideros armiger to investigate multimodal signal function in acoustic and olfactory aggressive displays.We monitored the physiological responses(heart rate[HR])when H.armiger was presented with 1 of 3 stimuli:territorial calls,forehead gland odors,and bimodal signals(calls+odors).Results showed that H.armiger rapidly increased their HR when exposed to any of the 3 stimuli.However,the duration of elevated HR and magnitude of change in HR increased significantly more when acoustic stimuli were presented alone compared with the presentation of olfactory stimuli alone.In contrast,the duration of elevated HR and magnitude of change in HR were significantly higher with bimodal stimuli than with olfactory stimuli alone,but no significant differences were found between the HR response to acoustic and bimodal stimuli.Our previous work showed that acoustic and chemical signals provided different types of information;here we describe experiments investigating the responses to those signals.These results suggest that olfactory and acoustic signals are non-redundant signal components,and that the acoustic component is the dominant modality in male H.armiger,at least as it related to HR.This study provides the first evidence that acoustic signals dominate over olfactory signals during agonistic interactions in a nocturnal mammal.
基金supported by the National Natural Science Foundation of China(Grant No.31922050)the Fund of the Jilin Province Science and Technology Development Project(Grant No.20220101273JC)+1 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.2412023QD026 and 2412023YQ002)the Special Foundation for National Science and Technology Basic Research Program of China(Grant No.2021FY100301).
文摘Anti-predation strategies are critical to animal survival and are fundamental to deciphering predator–prey interactions.As an important defense strategy,sensory predator detection(such as through acoustic and visual cues)enables animals to assess predation risk and execute predator-avoidance behavior;however,there are limited studies on the anti-predation behavior of nocturnal animals.The prey of bats provides an excellent representative system for examining the anti-predation behavior of nocturnal animals.Here,we broadcasted different types of echolocation calls of the bird-eating bat Ia io to two wild passerine birds,namely,Zosterops japonicus and Sinosuthora webbiana,that are preyed upon by I.io,and presented the birds with individual bats under different light intensities.The results showed that both bird species were able to perceive the low-frequency audible portion of the bats’echolocation calls;however,they did not exhibit escape responses to the acoustic stimuli.In the dark and under moonlit conditions,both bird species were unable to respond to active bats at close range and the birds only exhibited evasive flight behavior when bats approached or touched them.These results suggest that nocturnal passerine birds may not be able to use acoustic or visual cues to detect bats and adopt evasive maneuvers to avoid predation.This work suggests that bat predation pressure may not elicit primary predator-avoidance responses in nocturnal passerine birds.The results provide new insights into the anti-predation behavior of nocturnal animals.
基金supported by the National Natural Science Foundation of China(Grant nos.31872680,31922050,31670390)the Fund of the Jilin Province Science and Technology Development Project(Grant no.20180101024JC)。
文摘Signals containing parameter trade-offs are likely to be honest indicators of signaler quality because they are difficult to produce.Signals with a trill-rate/bandwidth trade-off have been described for many songbird species,one mouse,and one non-human primate species.However,there were no reports about whether there is a vocal performance trade-off in social calls of bats.This study investigated(1)a possible vocal performance trade-off in territorial calls of male Great Himalayan leaf-nosed bats,Hipposideros armiger,recorded from 9 locations in south China,and(2)the relationships between vocal performance(vocal deviation and consistency)and caller’s quality(body mass)to determine whether vocal performance honestly indicates a caller’s quality.Vocal deviation measures the deviation of a call relative to an extreme call and vocal consistency measures the spectral consistency across a string of syllables.Our results showed a significant negative correlation between syllable repetition rate and frequency bandwidth,suggesting a vocal performance trade-off similar to the one in songbirds.Further,there was a significant negative relationship between body mass and vocal deviation,but no significant correlation between body mass and vocal consistency.This study provides thefirst empirical evidence for a vocal performance trade-off of social calls in bats,and the potential for the level of performance to indicate caller quality.
