Laske Timothy G, Garshelis David L, Iaizzo Paul A
Cardiac Rhythm Disease Management, Medtronic, Incorporated, 8200 Coral Sea Street NE, MVS46, Mounds View, MN 55112, USA.
BMC Physiol. 2011 Aug 17;11:13. doi: 10.1186/1472-6793-11-13.
Bears are among the most physiologically remarkable mammals. They spend half their life in an active state and the other half in a state of dormancy without food or water, and without urinating, defecating, or physical activity, yet can rouse and defend themselves when disturbed. Although important data have been obtained in both captive and wild bears, long-term physiological monitoring of bears has not been possible until the recent advancement of implantable devices.
Insertable cardiac monitors that were developed for use in human heart patients (Reveal® XT, Medtronic, Inc) were implanted in 15 hibernating bears. Data were recovered from 8, including 2 that were legally shot by hunters. Devices recorded low heart rates (pauses of over 14 seconds) and low respiration rates (1.5 breaths/min) during hibernation, dramatic respiratory sinus arrhythmias in the fall and winter months, and elevated heart rates in summer (up to 214 beats/min (bpm)) and during interactions with hunters (exceeding 250 bpm). The devices documented the first and last day of denning, a period of quiescence in two parturient females after birthing, and extraordinary variation in the amount of activity/day, ranging from 0 (winter) to 1084 minutes (summer). Data showed a transition toward greater nocturnal activity in the fall, preceding hibernation. The data-loggers also provided evidence of the physiological and behavioral responses of bears to our den visits to retrieve the data.
Annual variations in heart rate and activity have been documented for the first time in wild black bears. This technique has broad applications to wildlife management and physiological research, enabling the impact of environmental stressors from humans, changing seasons, climate change, social interactions and predation to be directly monitored over multiple years.
熊是生理特征最为显著的哺乳动物之一。它们一生中一半时间处于活跃状态，另一半时间处于休眠状态，在此期间无需进食、饮水，也无需排尿、排便或进行身体活动，但受到干扰时能够苏醒并进行自我防御。尽管在圈养熊和野生熊身上都已获取了重要数据，但直到可植入设备最近取得进展，才能够对熊进行长期生理监测。
为人类心脏病患者研发的可插入式心脏监测器（Reveal® XT，美敦力公司）被植入15只正在冬眠的熊体内。从8只熊身上回收了数据，其中2只是被猎人合法射杀的。这些设备记录了熊在冬眠期间的低心率（超过14秒的停顿）和低呼吸频率（1.5次/分钟）、秋冬季节显著的呼吸性窦性心律失常，以及夏季（高达214次/分钟）和与猎人互动期间（超过250次/分钟）升高的心率。这些设备记录了筑巢的第一天和最后一天、两只分娩后的雌性熊分娩后一段静止期，以及每天活动量的巨大差异，范围从0（冬季）到1084分钟（夏季）。数据显示，在冬眠前的秋季，熊的夜间活动有增加的趋势。数据记录器还提供了熊对我们进入巢穴取回数据的生理和行为反应的证据。
首次记录了野生黑熊心率和活动的年度变化。这项技术在野生动物管理和生理研究方面有广泛应用，能够直接监测多年来人类环境压力源、季节变化、气候变化、社会互动和捕食的影响。
