Death Feigning by Ducks in Response to Predation by Red Foxes (Vulpes fulva)

1975 ◽  
Vol 94 (1) ◽  
pp. 108 ◽  
Author(s):  
Alan B. Sargeant ◽  
Lester E. Eberhardt
Keyword(s):  
Red Foxes ◽  
Death Feigning

scholarly journals Infectivity of gastropod-shed third-stage larvae of Angiostrongylus vasorum and Crenosoma vulpis to dogs

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
William Robbins ◽  
Gary Conboy ◽  
Spencer Greenwood ◽  
Roland Schaper
Keyword(s):  
Tap Water ◽  
Natural Infection ◽  
Angiostrongylus Vasorum ◽  
Intermediate Hosts ◽  
Red Foxes ◽  
Romaine Lettuce ◽  
Crenosoma Vulpis ◽  
Artificial Digestion ◽  
Third Stage ◽  
Limax Maximus

Abstract Background Metastrongyloid parasites Angiostrongylus vasorum and Crenosoma vulpis infect wild and domestic canids and are important pathogens in dogs. Recent studies indicate that gastropod intermediate hosts infected with various metastrongyloids spontaneously shed infective third-stage larvae (L3) into the environment via feces and mucus under laboratory conditions. Shed L3 retain motility up to 120 days, but whether they retain infectivity was unknown. Methods To assess the infectivity of shed L3, the heart/lungs of six red foxes (Vulpes vulpes) were obtained from trappers in Newfoundland, Canada. Lungs were examined for first-stage larvae (L1) by the Baermann technique. A high number of viable A. vasorum L1 and a low number of C. vulpis L1 were recovered from one fox; these were used to infect naïve laboratory-raised Limax maximus. L3 recovered from slugs by artificial digestion were fed to two naïve purpose-bred research beagles (100 L3/dog). L1 shed by these two dogs was used to infect 546 L. maximus (2000–10,000 L1/slug). L3 shedding was induced by anesthetizing slugs in soda water and transferring them into warm (45 °C) tap water for at least 8 h. Shed L3 recovered from slugs were aliquoted on romaine lettuce in six-well tissue culture plates (80–500 L3/well) and stored at 16 °C/75% relative humidity. Four naïve research beagles were then exposed to 100 L3/dog from larvae stored for 0, 2, 4, or 8 weeks, respectively, after shedding. Results All four dogs began shedding C. vulpis L1 by 26–36 days post-infection (PI). All four dogs began shedding A. vasorum L1 by 50 days PI. Conclusions L3 infectivity for the definitive host was retained in both metastrongyloids, indicating the potential for natural infection in dogs through exposure from environmental contamination. As an additional exposure route, eating or licking plant or other material(s) contaminated with metastrongyloid L3 could dramatically increase the number of dogs at risk of infection from these parasites. Graphic Abstract

scholarly journals Application of YOLOv4 for Detection and Motion Monitoring of Red Foxes

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1723
Author(s):  
Anne K. Schütz ◽  
Verena Schöler  ◽  
E. Tobias Krause  ◽  
Mareike Fischer  ◽  
Thomas Müller  ◽  
...  
Keyword(s):  
Animal Welfare ◽  
Early Recognition ◽  
Activity Patterns ◽  
Automatic Detection ◽  
Animal Husbandry ◽  
Video Data ◽  
Activity Level ◽  
Red Foxes ◽  
Experimental Conditions ◽  
Animal Activity

Animal activity is an indicator for its welfare and manual observation is time and cost intensive. To this end, automatic detection and monitoring of live captive animals is of major importance for assessing animal activity, and, thereby, allowing for early recognition of changes indicative for diseases and animal welfare issues. We demonstrate that machine learning methods can provide a gap-less monitoring of red foxes in an experimental lab-setting, including a classification into activity patterns. Therefore, bounding boxes are used to measure fox movements, and, thus, the activity level of the animals. We use computer vision, being a non-invasive method for the automatic monitoring of foxes. More specifically, we train the existing algorithm ‘you only look once’ version 4 (YOLOv4) to detect foxes, and the trained classifier is applied to video data of an experiment involving foxes. As we show, computer evaluation outperforms other evaluation methods. Application of automatic detection of foxes can be used for detecting different movement patterns. These, in turn, can be used for animal behavioral analysis and, thus, animal welfare monitoring. Once established for a specific animal species, such systems could be used for animal monitoring in real-time under experimental conditions, or other areas of animal husbandry.

Red foxes increase reproductive output of white spruce in a non-mast year

2021 ◽  
Vol 51 ◽  
pp. 11-19
Author(s):  
Caila E. Kucheravy ◽  
James D. Roth ◽  
John H. Markham
Keyword(s):  
Reproductive Output ◽  
White Spruce ◽  
Red Foxes

scholarly journals Factors Affecting Thanatosis in the Braconid Parasitoid Wasp Heterospilus prosopidis

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 48
Author(s):  
Mio Amemiya ◽  
Kôji Sasakawa
Keyword(s):  
Life History ◽  
Antipredator Behavior ◽  
Parasitoid Wasp ◽  
Ecological Perspective ◽  
Background Color ◽  
Factors Affecting ◽  
Death Feigning ◽  
Heterospilus Prosopidis ◽  
History Of

Thanatosis, also called death feigning, is often an antipredator behavior. In insects, it has been reported from species of various orders, but knowledge of this behavior in Hymenoptera is insufficient. This study examined the effects of sex, age (0 or 2 days old), temperature (18 or 25 °C), and background color (white, green, or brown) on thanatosis in the braconid parasitoid wasp Heterospilus prosopidis. Thanatosis was more frequent in 0-d-old individuals and in females at 18 °C. The duration of thanatosis was longer in females, but this effect of sex was weaker at 18 °C and in 0-d-old individuals. The background color affected neither the frequency nor duration. These results were compared with reports for other insects and predictions based on the life history of this species, and are discussed from an ecological perspective.

Morphological and immunohistochemical characteristics of spontaneous distemper infection in the brains of red foxes in Serbia

2019 ◽  
Vol 166 ◽  
pp. 142
Author(s):  
M. Aničić ◽  
P. Juntes ◽  
N. Vasković ◽  
S. Nešić ◽  
I. Vučićević ◽  
...  
Keyword(s):  
Red Foxes

Potential remedy against Echinococcus multilocularis in wild red foxes using baits with anthelmintic distributed around fox breeding dens in Hokkaido, Japan

Parasitology ◽  
2002 ◽  
Vol 125 (2) ◽  
pp. 119-129 ◽  
Author(s):  
H. TSUKADA ◽  
K. HAMAZAKI ◽  
S. GANZORIG ◽  
T. IWAKI ◽  
K. KONNO ◽  
...  
Keyword(s):  
Echinococcus Multilocularis ◽  
Red Fox ◽  
Red Foxes ◽  
Clethrionomys Rufocanus ◽  
Efficient Control ◽  
Positive Rate ◽  
Potential Remedy ◽  
Patent Infection

The effect of bait-delivered anthelmintic to reduce the prevalence of Echinococcus multilocularis in wild red foxes was evaluated in Koshimizu, in the eastern part of Hokkaido, Japan. The study area (200 km2) was divided into baited and non-baited sections. The anthelmintic baits were distributed around fox den sites in the baited section every month for 13 months. After 1 year of the anthelmintic bait distribution, the prevalence of E. multilocularis in foxes, evaluated either by the parasite egg examination (from 27.1 to 5.6%) or coproantigen ELISA (from 59.6 to 29.7%), decreased in the baited section contrasting to that in the non-baited section (parasite egg: from 18.8 to 24.2%; ELISA: from 41.9 to 45.8%). The prevalence of E. multilocularis in grey red-backed vole Clethrionomys rufocanus, caught around fox dens, born after bait distribution also decreased and was significantly lower than that in non-baited section. However, within the study periods, the coproantigen-positive rate in fox faeces sporadically increased, while egg-positive rate constantly decreased. Since coproantigen ELISA can detect pre-patent infection, this observation indicates that reinfection pressure in the baited section was still high even after the 13 months of anthelmintic bait distribution. Therefore, the bait distribution longer than our study period is required for the efficient control of E. multilocularis in wild red fox population.

Copulation reduces the duration of death-feigning behaviour in the sweetpotato weevil, Cylas formicarius

2009 ◽  
Vol 78 (5) ◽  
pp. 1145-1151 ◽  
Author(s):  
Takashi Kuriwada ◽  
Norikuni Kumano ◽  
Keiko Shiromoto ◽  
Dai Haraguchi
Keyword(s):  
Sweetpotato Weevil ◽  
Death Feigning ◽  
Cylas Formicarius
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