Christiansen F O., Bakken M, Braastad B O.
North Trondelag Research Institute, P.O. Box 2533, N-7729, Steinkjer, Norway
Appl Anim Behav Sci. 2001 Apr 26;72(2):105-114. doi: 10.1016/s0168-1591(00)00208-2.
Sheep grazing on unfenced mountain pasture may be attacked by loose dogs, which may chase and kill sheep and separate lambs from their mothers. We have earlier shown that testing dogs individually towards sheep with an electronic dog collar may effectively reduce the chasing propensity 1 year later. The aim of this study was to investigate whether and how a non-chasing and a chasing companion dog influence sheep chasing in test dogs (20 Norwegian Elkhounds, grey), and whether this varies with sex or age. The test dogs' predatory behaviour towards sheep was examined by observation of the dogs in a fenced enclosure with sheep in 5min tests together with, first, a non-chasing (Hamilton stoever, a hound breed) and 2-3 days later a chasing (Border collie) companion dog. Physical contact with sheep was prevented. Initially, the test dogs exhibited a higher chasing motivation towards sheep in tests with a chasing, as compared with a non-chasing, companion (P<0.001). During the entire test, 60% of the dogs attacked sheep when accompanied by the non-chaser. All dogs attacked sheep when the chasing companion was present (P=0.008), although in only 8 of 20 cases the companion dog chased simultaneously with the test dog. In the chasing-companion tests, the attack latency was shorter (P<0.001) than in tests with a non-chasing companion. The attack severity was higher when attacking alone than when attacking together with the chasing companion (P=0.033). In these tests, the higher the attack severity, the shorter was the attack latency (P=0.006). A sequence analysis on chasing-companion tests showed that test dogs generally started with observing or showing interest in sheep, followed by attacks, which increased in severity. No sex differences were observed. In non-chasing companion tests, dogs aged up to 2.5 years exhibited a weaker initial hunting motivation than older dogs (P=0.025), but during the entire test were more inclined to attack (P=0.019). Taken together, our findings indicate that a companion dog showing intentions of predatory behaviour stimulates predatory chase in another dog, while a non-chasing companion has a limited influence on this. In tests certifying dogs for their refrainment of chasing sheep, well trained Border collies approaching sheep on command might be used to reveal the full predatory potential of the dog being tested.
在没有围栏的山地牧场上吃草的羊可能会受到流浪狗的攻击，这些狗可能会追逐并杀死羊，还会使小羊与母羊分离。我们之前已经表明，使用电子狗项圈对狗单独进行针对羊的测试，可能会在一年后有效降低其追逐倾向。本研究的目的是调查一只不追逐的同伴狗和一只追逐的同伴狗是否以及如何影响测试狗（20只挪威猎麋犬，灰色）对羊的追逐行为，以及这种影响是否因性别或年龄而异。通过在一个有围栏的围场中观察狗与羊共处5分钟的测试来检查测试狗对羊的捕食行为，首先是与一只不追逐的狗（汉密尔顿史托弗犬，一种猎犬品种）一起，2 - 3天后是与一只追逐的（边境牧羊犬）同伴狗一起。防止狗与羊有身体接触。最初，与不追逐的同伴狗相比，测试狗在与追逐的同伴狗一起测试时对羊表现出更高的追逐动机（P<0.001）。在整个测试过程中，60%的狗在与不追逐的同伴狗在一起时攻击了羊。当有追逐的同伴狗在场时，所有狗都攻击了羊（P = 0.008），尽管在20个案例中只有8个案例中同伴狗与测试狗同时追逐。在有追逐同伴狗的测试中，攻击潜伏期比与不追逐的同伴狗测试时更短（P<0.001）。单独攻击时的攻击严重程度高于与追逐同伴狗一起攻击时（P = 0.033）。在这些测试中，攻击严重程度越高，攻击潜伏期越短（P = 0.006）。对有追逐同伴狗的测试进行序列分析表明，测试狗通常首先观察或对羊表现出兴趣，然后是攻击，攻击严重程度逐渐增加。未观察到性别差异。在有不追逐同伴狗的测试中，2.5岁及以下的狗最初的狩猎动机比年龄较大的狗弱（P = 0.025），但在整个测试过程中更倾向于攻击（P = 0.019）。综上所述，我们的研究结果表明，表现出捕食行为意图的同伴狗会刺激另一只狗的捕食性追逐，而不追逐的同伴狗对此影响有限。在对狗进行不追逐羊的认证测试中，训练有素的边境牧羊犬根据指令接近羊，可能会被用来揭示被测试狗的全部捕食潜力。
