鸟类对猫捕食敏感性的种间差异研究

哺乳类捕获猎物的方法与猛禽不同,前者通常依靠伏击捕猎.这种捕猎行为上的差异,对不同猎物对被猎杀的敏感性有重要影响,并能改变猎物的日常行为.在分析了大量的猎物丰富度和可获得猎物等数据的基础上,我们研究了鸟类对家猫(Felis catus)捕食的敏感性.不同鸟种对被猫捕食的敏感性与对被雀鹰(Accipiter nisus)捕食的敏感性无显著相关性,但与对被苍鹰(Accipiter gentilis)捕食的易感性呈显著相关.鸟类对被猫和雀鹰捕食的敏感性被分别用来预测了它们对被苍鹰捕食的敏感性.鸟类尾羽缺失的比例会随着被猫捕食的敏感性的加大而增多,也验证了我们关于鸟类对被猫捕食敏感性的看法.猫对雄鸟的捕食比例较高,尤其当雄鸟处于植被较低层的位置鸣唱以及鸣唱时起飞距离较短时,被捕食的几率更高.集群繁殖的鸟类对被捕食的敏感性要低于独居鸟类.对细菌感染免疫力较高的鸟类同样也对猫的捕食有着较高的敏感性.这些结果说明猫的捕食己成为一个重要的选择压力,对普通鸟类的抗捕食行为、性别炫耀和免疫功能产生影响.     

Applying the precautionary principle to the issue of impacts by pet cats on urban wildlife

Despite evidence that pet cats prey on urban wildlife and may transmit disease, there is uncertainty over whether they cause declines in wildlife populations. The uncertainty fosters disagreement about whether and how pet cats should be managed, and hampers the implementation of regulations. We suggest that the precautionary principle could be used in this context. The principle mandates action to protect the environment when there is a scientifically plausible but unproven risk, and provides a rationale for immediate intervention to protect wildlife from pet cats while we await definitive studies. In applying a 4-step guide for implementing the precautionary principle, we argue that: (i) current data documenting wildlife mortality caused by pet cats satisfy the precautionary trigger of scientifically plausible risk; (ii) the risk of significant declines or local extinctions of threatened wildlife, coupled with uncertainty in establishing population declines in response to pet cats, argue for strong levels of precaution; (iii) precautionary measures that should be considered include, but are not limited to, restrictions on the maximum number of cats allowed/household, mandatory sterilisation and registration of pet cats, curfews, requiring pet cats roaming outdoors to wear collar-mounted predation-deterrents or compulsory confinement of cats to their owners’ premises; and (iv) the principle’s requirement for extensive consultation in implementing precautionary measures should encourage collaborations involving conservation biologists, veterinarians, animal welfare activists, concerned citizens and municipal officers. Adherence to these steps should assist in choosing actions that have broad support and are applicable to unique local circumstances.     

Pine heartwood formation as a maturation phenomenon

The inverse of the relative increment rate of size is proposed as a measure of the maturity of a forest tree. The heartwood content within bole cross sections is modeled semiempirically using asymptotic fitting. It is shown that the present proposal for a definition of maturity statistically explains heartwood content far better than age or size. The heartwood content appears to be independent on growth rate and tree size.     

Dying to be clean: pen trials of novel cat and fox control devices

Predation by feral cats (Felis catus) and red foxes (Vulpes vulpes) are key threatening processes for many endangered wildlife species. Toxin delivery through compulsive oral grooming is a potential mechanism to supplement existing control techniques for feral cats and red foxes, particularly when high prey densities reduce the uptake of toxic food baits by cats. We investigated the efficacy of different grooming traps by applying a gel containing toxic para-aminopropiophenone (PAPP) to the fur of feral cats and red foxes in experimental pens. Grooming behaviour and signs of poisoning in these animals were recorded by video. More cats interacted with “walk past” grooming traps triggered by sensor beams than with trap models that required the cat to enter a pipe or baited cage. After triggering a trap that had applied PAPP gel to their fur, 14 of 16 feral cats showed symptoms of anoxia, and 8 of these cats were dead by the following morning without exhibiting signs of distress. Seven of 12 foxes were observed to groom fur to which toxic gel had been applied and 3 of these ingested a lethal quantity of PAPP as a result. Our successful proof-of-concept trials support further development of grooming trap sensors and toxin delivery mechanisms to provide humane and targeted feral cat control, although this technique is unlikely to be as successful for fox control, given that foxes appear to not groom as fastidiously as cats.     

Habitat selection models for European wildcat conservation

Populations of the European wildcat (Felis silvestris) are only slowly recovering in Central Europe after a severe decline in the last centuries and require specific conservation plans in many areas. However, detailed information on wildcat occurrence and habitat requirements is still scarce and controversial. We present a fine-scale habitat selection model for wildcats based on detailed species and land use information and evaluate its accuracy to predict habitat distribution in new areas. We analysed habitat use within home ranges using single locations of 12 radio-tracked individuals from south western Germany. Several competing models were fitted and compared using generalised linear mixed models (GLMM) and information-theoretic approaches. Radio-tracking data of 9 and 10 wildcats from two distant areas were used to evaluate the models. The selected model predicted habitat associated to close distance to forest, watercourses and meadows and a critical distance to villages, single houses and roads. To predict area suitable for home ranges we superimposed rules derived from home range attributes at a higher level of selection. Predictions from the combination of the fine-scale habitat model and home range rules matched well with more than 2000 wildcat observations of south-western Germany. We discuss the application of the model in wildcat conservation for finding potential reintroduction sites, identifying small isolated populations and aiding in the evaluation of the needs of mitigation and compensation within the scope of the European Habitats Directive.     

兔狲血液蛋白质和酶的电泳分析

采用聚丙烯酰胺凝胶电泳法对２只兔狲的４种血液蛋白质表型和３种血液同工酶酶谱进行研究。结果发现：①被检兔狲的血红蛋白（ＨＢ）,白蛋白（ＡＬＢ）和后白蛋白（Ｐａ）分别呈单一的ＨＢＡＢ,ＡＬＢＡＡ和ＰａＡＡ型,运铁蛋白（ＴＦ）有ＴＦＡＢ和ＴＦＢＢ两种表型;②血清碱性磷酸酶（ＡＬＰ）由ＡＬＰＡ,ＡＬＰＢ,ＡＬＰＣ和ＡＬＰＤ四种同工酶组成;③血清酯酶（ＥＳ）由ＥＳＩ和ＥＳＩＶ两种同工酶共７条区带组成;④血清乳酸脱氢酶（Ｓ－ＬＤＨ）由ＬＤＨ１,ＬＤＨ２,ＬＤＨ３,ＬＤＨ４和ＬＤＨ５五种同工酶组成,红细胞内只有前四种ＬＤＨ同工酶。     

Reproductive hormones monthly variation in free-ranging European wildcats: Lack of association with faecal marking

Integrating ecophysiological and behavioural discoveries in conservation and management plans is essential to preserve scarce and elusive species such as the European wildcat (Felis silvestris). The purpose of this study was to characterize the monthly variation in the steroid reproductive hormone metabolite levels (oestradiol, progesterone and testosterone) in this species and to test its possible association with a monthly pattern of faecal marking. By collecting fresh faecal samples in Montes do Invernadeiro Natural Park (Galicia, Northwest Spain) each month, we obtained a total of 110 samples belonging to 25 different individuals. We conducted enzyme immunoassays which allowed us to track the annual variation in reproductive hormone excretion patterns in wildcat scats. Furthermore, we also evaluated the possible relation between the faeces used as marks and the reproductive hormone levels. We found that oestradiol and progesterone metabolite levels exhibited a distinct pattern, both increasing during the breeding months. Oestradiol metabolite larger peaks were found during March and April, whereas the highest concentration of progesterone metabolites appeared in July. On the contrary, testosterone metabolite levels did not significantly change depending on the month. Moreover, we did not find any evidence that the faecal marking behaviour pattern was associated with reproductive hormone metabolite levels. It seems that other factors related to habitat and food resources could be more important in the performance of this behaviour.     

Investigation of multiple Felis catus papillomavirus types (-1/-2/-3/-4/-5/-6) DNAs in feline oral squamous cell carcinoma: a multicentric study

Recent evidence suggests a possible association of Felis catus papillomavirus type 2 (FcaPV-2) DNA with feline oral squamous cell carcinoma (FOSCC). In this study, type-specific PCR targeting two genes (L1/E6 or E1/E6) of FcaPV-1/-2/-3/-4/-5/-6 was performed to detect viral DNA in a large amount of FOSCC samples collected in Italy and Austria. FcaPV-1/-2/-3/-4/-5 were detected in 7/113 (6.2%), 7/93 (7.5%), 6/113 (5.3%), 1/113 (0.9%) and 2/113 (1.8%) specimens, respectively, with different prevalences in Italian vs. Austrian samples, whilst FcaPV-6 went undetected. Our results confirms that FcaPV-2 is the most prevalent in FOSCC, followed by FcaPV-1/-3 and suggest that FcaPVs have variable circulation rates in European countries.