據(jù)美國《科學(xué)》雜志在線新聞報(bào)道,，一項(xiàng)持續(xù)4年的對加拿大不列顛哥倫比亞省沿岸的狼毛和狼糞進(jìn)行的研究顯示,，在整個(gè)秋季,，這種食肉動物的食譜有70%是由大麻哈魚構(gòu)成的。通常認(rèn)為,，鹿肉是狼最愛吃的食物,，因此當(dāng)發(fā)現(xiàn)它們也對河中的大麻哈魚感興趣時(shí)，研究人員無不感到非常驚訝,。不過有人就指出,，與鹿相比，大麻哈魚有一個(gè)重要的優(yōu)勢——被魚鰭在臉上扇一下比叫鹿蹄子在肋骨上踹一腳輕得多,。研究人員在9月2日的《BMC生態(tài)學(xué)》（BMC Ecology）上報(bào)告了這一發(fā)現(xiàn),。（生物谷Bioon.com）
生物谷推薦原始出處：
BMC Ecology，2008, 8:14,，Chris T Darimont, Paul C Paquet and Thomas E Reimchen
Spawning salmon disrupt trophic coupling between wolves and ungulate prey in coastal British Columbia
Chris T Darimont , Paul C Paquet and Thomas E Reimchen
Background
As a cross-boundary resource subsidy, spawning salmon can strongly affect consumer and ecosystem ecology. Here we examine whether this marine resource can influence a terrestrial wolf-deer (Canis lupus-Odocoileus hemionus) predator-prey system in coastal British Columbia, Canada. Data on resource availability and resource use among eight wolf groups for three seasons over four years allow us to evaluate competing hypotheses that describe salmon as either an alternate resource, consumed in areas where deer are scarce, or as a targeted resource, consumed as a positive function of its availability. Faecal (n = 2203 wolf scats) and isotopic analyses (n = 60 wolf hair samples) provide independent data sets, also allowing us to examine how consistent these common techniques are in estimating foraging behaviour.
Results
At the population level during spring and summer, deer remains occurred in roughly 90 and 95% of faeces respectively. When salmon become available in autumn, however, the population showed a pronounced dietary shift in which deer consumption among groups was negatively correlated (r = -0.77, P <0.001) with consumption of salmon, which occurred in 40% of all faeces and up to 70% of faeces for some groups. This dietary shift as detected by faecal analysis was correlated with seasonal shifts in d13C isotopic signatures (r = 0.78; P = 0.008), which were calculated by intra-hair comparisons between segments grown during summer and fall. The magnitude of this seasonal isotopic shift, our proxy for salmon use, was related primarily to estimates of salmon availability, not deer availability, among wolf groups.
Conclusions
Concordance of faecal and isotopic data suggests our intra-hair isotopic methodology provides an accurate proxy for salmon consumption, and might reliably track seasonal dietary shifts in other consumer-resource systems. Use of salmon by wolves as a function of its abundance and the adaptive explanations we provide suggest a long-term and widespread association between wolves and salmon. Seasonally, this system departs from the common wolf-ungulate model. Broad ecological implications include the potential transmission of marine-based disease into terrestrial systems, the effects of marine subsidy on wolf-deer population dynamics, and the distribution of salmon nutrients by wolves into coastal ecosystems.
