Background:Brood parasitic birds such as cuckoos(Cuculus spp.)can reduce their host’s reproductive success.Such selection pressure on the hosts has driven the evolution of defense behaviors such as egg rejection agai...Background:Brood parasitic birds such as cuckoos(Cuculus spp.)can reduce their host’s reproductive success.Such selection pressure on the hosts has driven the evolution of defense behaviors such as egg rejection against cuckoo parasitism.Studies have shown that Cinereous Tits(Parus cinereus)in China have a good ability for recognizing foreign eggs.However,it is unclear whether egg spots play a role in egg recognition.The aims of our study were to investigate the egg recognition ability of two Cinereous Tit populations in China and to explore the role of spots in egg recognition.Methods:To test the effect of eggshell spots on egg recognition,pure white eggs of the White-rumped Munia(Lonchura striata)and eggs of White-rumped Munia painted with red brown spots were used to simulate experimental parasitism.Results:Egg experiments showed that Cinereous Tits rejected 51.5%of pure white eggs of the White-rumped Munia,but only 14.3%of spotted eggs of the White-rumped Munia.There was a significant difference in egg recognition and rejection rate between the two egg types.Conclusions:We conclude that eggshell spots on Cinereous Tit eggs had a signaling function and may be essential to tits for recognizing and rejecting parasitic eggs.展开更多
Throughout the animal kingdom there are species that have two or more phenotypic forms or ‘morphs＇, and many of these are amphibians. In North America, the red-backed salamander Plethodon cinereus can have either a ...Throughout the animal kingdom there are species that have two or more phenotypic forms or ‘morphs＇, and many of these are amphibians. In North America, the red-backed salamander Plethodon cinereus can have either a red dorsal stripe or no dorsal stripe （lead-phase form）, and evidence to date indicates the lead-phase form incurs a greater number of attacks from predators. In a recent collection of 51 P cinereus, blood smears of both color morphs （35 red-stripe, 16 lead-phase） were examined to obtain numbers of circulating leukocytes （via light microscopy）, which can be used to indirectly estimate levels of stress hormones in vertebrates via a ‘hematological stress index＇, which is the ratio between the number of two leukocyte types （neutrophils and lymphocytes）. Our results showed that lead-phase salamanders tended to have greater numbers of circulating neutrophils and lower numbers of circulating lymphocytes than red-stripe morphs, leading to higher average neutrophil-lymphocyte ratios in lead-phase individuals. Since the salamanders were held （refrigerated） for 7 days before sampling, we cannot be certain if this effect is a stress reaction to the captivity or the normal level for this morph. However comparison with two sets of related salamanders that were captured and sampled immediately indicates the red-stripe salamanders were either not stressed from the captivity at all, or their white blood cell distributions had returned to normal after 7 days of captivity. Taken together, our results indicate that lead-phase forms of P. cinereus have higher stress levels than the red-stripe forms, which may be a consequence of their higher exposure to, and/or attacks from, predators. They may also indicate that the lead-phase form is less-suited to captivity than the red-stripe form of this species.展开更多
Pampus cinereus （Bloch, 1795） （Stromateidae）, a species believed to be widely distributed throughout the Indo-Western Pacific region, was redescribed and a neotype was designated. The designation of a neotype was ...Pampus cinereus （Bloch, 1795） （Stromateidae）, a species believed to be widely distributed throughout the Indo-Western Pacific region, was redescribed and a neotype was designated. The designation of a neotype was necessary because of ambiguous data in Bloch＇s original description and the loss of the original type specimen. Morphological data indicated that 10 recently-collected specimens from the coasts of southem China agreed well with Bloch＇s original description and figure ofP. cinereus. A neotype for this species was selected from among the 10 specimens, and a detailed description is presented in this paper.展开更多
We investigated how exposure duration （time that two individuals initially interact） and separation interval （time be- tween the initial interaction and a subsequent interaction） affect recognition memory of consp...We investigated how exposure duration （time that two individuals initially interact） and separation interval （time be- tween the initial interaction and a subsequent interaction） affect recognition memory of conspecifics in male red-backed sala- manders Plethodon cinereus. Previous studies have demonstrated that this species aggressively defends territories. We recorded aggressive behavior to assess recognition memory, because aggression is more intense toward previously unencountered indi- viduals compared to previously encountered individuals in this species. We found that with 15-min exposures and 5-day separa- tion intervals, focal males did not spend significantly more time threatening ＇unfamiliar＇ intruders than ＇familiar＇ intruders. After either 8-hour exposures and 5-day separation intervals and 5-day exposures and 5-day separation intervals, focal males spent sig- nificantly more time threatening unfamiliar intruders than familiar intruders. These results suggest that male red-backed salaman- ders can remember familiar conspecifics （e.g., territorial neighbors） after at least an 8-hour exposure duration and that memory persists at least as long as 5 days. After 5-day exposure and 15-day separation intervals, we found no significant difference in ag- gressive behavior toward familiar and unfamiliar intruders. Long separation intervals （15 days） may lead either to loss of memory of previously familiar individuals or, alternatively, aggressive reassessment of individuals as only a change in behavior indicates positively that memory has occurred. Thus, variance in territorial defense within an individual may depend on its ability to recog- nize conspecific males .展开更多
During 2009 and 2010, 23 night-time mosquito captures were made at Kanci obora in south-eastern Moravia, Czech Republic. It was used in the Centers for Disease Control and Prevention （CDCP） miniature light traps wit...During 2009 and 2010, 23 night-time mosquito captures were made at Kanci obora in south-eastern Moravia, Czech Republic. It was used in the Centers for Disease Control and Prevention （CDCP） miniature light traps with CO2 （dry ice） and baited lard-can traps in which sentinel animals were replaced with a container filled with CO2 （dry ice）. In the observed period, a total of 31,882 female mosquitoes were captured by CDC miniature light traps with CO2. Lard-can traps baited with CO2 captured 995 females under the same conditions, which is just 3.12% of the quantity from the CDC traps. At the same time, there were significant differences in the proportional captures of various species. Compared to CDC miniature light traps, baited lard-can traps much more often captured Aedes cinereus （16.58% of total versus 1.93% in CDC traps）, Culex modestus （15.48% versus 4.62%）, and Ae. rossicus （6.13% versus 2.67%）. On the other hand, capture of female Ae. vexans was proportionally much lower （15.38% versus 36.41%）. Capture of Cx. pipiens was more or less the same 14.77% （miniature light traps） and 15.76% （baited lard-can traps）. The occurrence of the calamity species Ae. sticticus was proportionally very high in both trap types （30.05% in lard-can traps baited with CO2, 33.58% in CDC miniature light traps）. The findings prove that a trap＇s design itself significantly affects not only the overall capture of mosquitoes but also the proportional representation of individual species.展开更多
基金funded by the National Natural Science Foundation of China(Nos.31772453 and 31970427 to WL,No.31672303 to CY and No.31770419 to HW)
文摘Background:Brood parasitic birds such as cuckoos(Cuculus spp.)can reduce their host’s reproductive success.Such selection pressure on the hosts has driven the evolution of defense behaviors such as egg rejection against cuckoo parasitism.Studies have shown that Cinereous Tits(Parus cinereus)in China have a good ability for recognizing foreign eggs.However,it is unclear whether egg spots play a role in egg recognition.The aims of our study were to investigate the egg recognition ability of two Cinereous Tit populations in China and to explore the role of spots in egg recognition.Methods:To test the effect of eggshell spots on egg recognition,pure white eggs of the White-rumped Munia(Lonchura striata)and eggs of White-rumped Munia painted with red brown spots were used to simulate experimental parasitism.Results:Egg experiments showed that Cinereous Tits rejected 51.5%of pure white eggs of the White-rumped Munia,but only 14.3%of spotted eggs of the White-rumped Munia.There was a significant difference in egg recognition and rejection rate between the two egg types.Conclusions:We conclude that eggshell spots on Cinereous Tit eggs had a signaling function and may be essential to tits for recognizing and rejecting parasitic eggs.
基金Funding for AKD during this project was provided by the DBWarnell School of Forestry and Natural Resources and a grant from the Morris Animal FoundationSupport for the field word of this project came form an NSF grant (NSF-DEB DEB0542974)
文摘Throughout the animal kingdom there are species that have two or more phenotypic forms or ‘morphs＇, and many of these are amphibians. In North America, the red-backed salamander Plethodon cinereus can have either a red dorsal stripe or no dorsal stripe （lead-phase form）, and evidence to date indicates the lead-phase form incurs a greater number of attacks from predators. In a recent collection of 51 P cinereus, blood smears of both color morphs （35 red-stripe, 16 lead-phase） were examined to obtain numbers of circulating leukocytes （via light microscopy）, which can be used to indirectly estimate levels of stress hormones in vertebrates via a ‘hematological stress index＇, which is the ratio between the number of two leukocyte types （neutrophils and lymphocytes）. Our results showed that lead-phase salamanders tended to have greater numbers of circulating neutrophils and lower numbers of circulating lymphocytes than red-stripe morphs, leading to higher average neutrophil-lymphocyte ratios in lead-phase individuals. Since the salamanders were held （refrigerated） for 7 days before sampling, we cannot be certain if this effect is a stress reaction to the captivity or the normal level for this morph. However comparison with two sets of related salamanders that were captured and sampled immediately indicates the red-stripe salamanders were either not stressed from the captivity at all, or their white blood cell distributions had returned to normal after 7 days of captivity. Taken together, our results indicate that lead-phase forms of P. cinereus have higher stress levels than the red-stripe forms, which may be a consequence of their higher exposure to, and/or attacks from, predators. They may also indicate that the lead-phase form is less-suited to captivity than the red-stripe form of this species.
基金Supported by the National Natural Science Foundation of China (Nos.31172053, 41276166)
文摘Pampus cinereus （Bloch, 1795） （Stromateidae）, a species believed to be widely distributed throughout the Indo-Western Pacific region, was redescribed and a neotype was designated. The designation of a neotype was necessary because of ambiguous data in Bloch＇s original description and the loss of the original type specimen. Morphological data indicated that 10 recently-collected specimens from the coasts of southem China agreed well with Bloch＇s original description and figure ofP. cinereus. A neotype for this species was selected from among the 10 specimens, and a detailed description is presented in this paper.
文摘We investigated how exposure duration （time that two individuals initially interact） and separation interval （time be- tween the initial interaction and a subsequent interaction） affect recognition memory of conspecifics in male red-backed sala- manders Plethodon cinereus. Previous studies have demonstrated that this species aggressively defends territories. We recorded aggressive behavior to assess recognition memory, because aggression is more intense toward previously unencountered indi- viduals compared to previously encountered individuals in this species. We found that with 15-min exposures and 5-day separa- tion intervals, focal males did not spend significantly more time threatening ＇unfamiliar＇ intruders than ＇familiar＇ intruders. After either 8-hour exposures and 5-day separation intervals and 5-day exposures and 5-day separation intervals, focal males spent sig- nificantly more time threatening unfamiliar intruders than familiar intruders. These results suggest that male red-backed salaman- ders can remember familiar conspecifics （e.g., territorial neighbors） after at least an 8-hour exposure duration and that memory persists at least as long as 5 days. After 5-day exposure and 15-day separation intervals, we found no significant difference in ag- gressive behavior toward familiar and unfamiliar intruders. Long separation intervals （15 days） may lead either to loss of memory of previously familiar individuals or, alternatively, aggressive reassessment of individuals as only a change in behavior indicates positively that memory has occurred. Thus, variance in territorial defense within an individual may depend on its ability to recog- nize conspecific males .
文摘During 2009 and 2010, 23 night-time mosquito captures were made at Kanci obora in south-eastern Moravia, Czech Republic. It was used in the Centers for Disease Control and Prevention （CDCP） miniature light traps with CO2 （dry ice） and baited lard-can traps in which sentinel animals were replaced with a container filled with CO2 （dry ice）. In the observed period, a total of 31,882 female mosquitoes were captured by CDC miniature light traps with CO2. Lard-can traps baited with CO2 captured 995 females under the same conditions, which is just 3.12% of the quantity from the CDC traps. At the same time, there were significant differences in the proportional captures of various species. Compared to CDC miniature light traps, baited lard-can traps much more often captured Aedes cinereus （16.58% of total versus 1.93% in CDC traps）, Culex modestus （15.48% versus 4.62%）, and Ae. rossicus （6.13% versus 2.67%）. On the other hand, capture of female Ae. vexans was proportionally much lower （15.38% versus 36.41%）. Capture of Cx. pipiens was more or less the same 14.77% （miniature light traps） and 15.76% （baited lard-can traps）. The occurrence of the calamity species Ae. sticticus was proportionally very high in both trap types （30.05% in lard-can traps baited with CO2, 33.58% in CDC miniature light traps）. The findings prove that a trap＇s design itself significantly affects not only the overall capture of mosquitoes but also the proportional representation of individual species.
