Predation of archival tagged Dolly Varden, Salvelinus malma, reveals predator avoidance behaviour and tracks feeding events by presumed beluga whale, Delphinapterus leucas, in the Beaufort Sea

IF 2.4 3区环境科学与生态学 Q2 BIODIVERSITY CONSERVATION

Animal Biotelemetry Pub Date : 2021-09-22 DOI:10.21203/RS.3.RS-910528/V1

C. Gallagher, Luke Storrie, Michael B. Courtney, K. Howland, E. V. Lea, S. MacPhee, L. Loseto

{"title":"Predation of archival tagged Dolly Varden, Salvelinus malma, reveals predator avoidance behaviour and tracks feeding events by presumed beluga whale, Delphinapterus leucas, in the Beaufort Sea","authors":"C. Gallagher, Luke Storrie, Michael B. Courtney, K. Howland, E. V. Lea, S. MacPhee, L. Loseto","doi":"10.21203/RS.3.RS-910528/V1","DOIUrl":null,"url":null,"abstract":"Background We report compelling evidence suggesting a predation event of a pop-up satellite archival tagged anadromous Dolly Varden ( Salvelinus malma ) by a marine mammal during summer in the Beaufort Sea based on abrupt changes in temperature and vertical movements. This observation provides insight on predator avoidance behaviour by Dolly Varden and the predator’s feeding frequency while the tag was ingested. Based on published distribution and ecology information, we presumed the predator was a beluga whale ( Delphinapterus leucas ). Supplemental satellite telemetry data from previously tagged Dolly Varden and beluga whales were used to determine the extent of spatial and vertical overlap between species in the area where predation occurred. Results Prior to the predation event, depths and temperatures occupied by the tagged Dolly Varden averaged 1.1 m and 3.1 °C, respectively. On July 7, 2020, depths remained shallow apart from a sudden dive to 12.5 m (16:45 UTC) followed by a precipitous increase in temperature from 4.4 to 27.1 °C (16:52 UTC) suggesting predation by an endotherm. Subsequent readings indicated the endotherm had a resting stomach temperature of 36.1 °C. Including the predation event, eight separate feeding events were inferred during the 20-h period the tag was ingested (before presumed regurgitation) based on subsequent declines in stomach temperatures (mean decline to 31.1 °C) that took an average of 24.1 min to return to resting temperature. The predator occupied mainly shallow depths (mean = 2.3 m), overlapping with tagged belugas that spent 76.9% of their time occupying waters ≤ 2.5 m when frequenting the area occupied by tagged Dolly Varden in the Canadian Beaufort Sea in July. Back-calculation based on tag drift and mean displacement by tagged belugas indicated the predation likely occurred west of the Mackenzie Delta. Conclusion Our findings provide new information on both anti-predator behaviour by, and marine predators of, Dolly Varden in the Beaufort Sea. We provide the first estimate of feeding frequency and stomach temperature recovery in a presumed wild beluga, and evidence for shallow foraging behaviour by belugas. Elucidating the likely predator and exploring the extent of overlap between Dolly Varden and beluga whales contributes towards knowledge on the trophic interactions in the Beaufort Sea.","PeriodicalId":37711,"journal":{"name":"Animal Biotelemetry","volume":"9 1","pages":"1-17"},"PeriodicalIF":2.4000,"publicationDate":"2021-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Animal Biotelemetry","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.21203/RS.3.RS-910528/V1","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIODIVERSITY CONSERVATION","Score":null,"Total":0}

引用次数: 2

Abstract

Background We report compelling evidence suggesting a predation event of a pop-up satellite archival tagged anadromous Dolly Varden ( Salvelinus malma ) by a marine mammal during summer in the Beaufort Sea based on abrupt changes in temperature and vertical movements. This observation provides insight on predator avoidance behaviour by Dolly Varden and the predator’s feeding frequency while the tag was ingested. Based on published distribution and ecology information, we presumed the predator was a beluga whale ( Delphinapterus leucas ). Supplemental satellite telemetry data from previously tagged Dolly Varden and beluga whales were used to determine the extent of spatial and vertical overlap between species in the area where predation occurred. Results Prior to the predation event, depths and temperatures occupied by the tagged Dolly Varden averaged 1.1 m and 3.1 °C, respectively. On July 7, 2020, depths remained shallow apart from a sudden dive to 12.5 m (16:45 UTC) followed by a precipitous increase in temperature from 4.4 to 27.1 °C (16:52 UTC) suggesting predation by an endotherm. Subsequent readings indicated the endotherm had a resting stomach temperature of 36.1 °C. Including the predation event, eight separate feeding events were inferred during the 20-h period the tag was ingested (before presumed regurgitation) based on subsequent declines in stomach temperatures (mean decline to 31.1 °C) that took an average of 24.1 min to return to resting temperature. The predator occupied mainly shallow depths (mean = 2.3 m), overlapping with tagged belugas that spent 76.9% of their time occupying waters ≤ 2.5 m when frequenting the area occupied by tagged Dolly Varden in the Canadian Beaufort Sea in July. Back-calculation based on tag drift and mean displacement by tagged belugas indicated the predation likely occurred west of the Mackenzie Delta. Conclusion Our findings provide new information on both anti-predator behaviour by, and marine predators of, Dolly Varden in the Beaufort Sea. We provide the first estimate of feeding frequency and stomach temperature recovery in a presumed wild beluga, and evidence for shallow foraging behaviour by belugas. Elucidating the likely predator and exploring the extent of overlap between Dolly Varden and beluga whales contributes towards knowledge on the trophic interactions in the Beaufort Sea.

查看原文本刊更多论文

在波弗特海，档案标记的多利·瓦尔登，Salvelinus malma，揭示了捕食者的躲避行为，并追踪了被认为是白鲸的进食事件，Delphinapterus leucas

背景我们报告了令人信服的证据，表明夏季在博福特海，一种海洋哺乳动物基于温度和垂直运动的突然变化，对一个弹出式卫星档案标记的溯河产卵Dolly Varden（Salvelinus malma）进行了捕食。这一观察结果为Dolly Varden的捕食者回避行为以及捕食者在摄入标签时的进食频率提供了见解。根据已公布的分布和生态学信息，我们推测捕食者是一头白鲸。之前标记的Dolly Varden和白鲸的补充卫星遥测数据被用来确定发生捕食的地区物种之间的空间和垂直重叠程度。结果在捕食事件之前，被标记的Dolly Varden的平均深度和温度分别为1.1米和3.1°C。2020年7月7日，除了突然潜水至12.5米（16:45 UTC），随后温度从4.4°C急剧上升至27.1°C（16:52 UTC），表明吸热捕食外，深度仍然较浅。随后的读数表明，吸热动物的静息胃温度为36.1°C。包括捕食事件在内，根据随后胃温度的下降（平均下降至31.1°C）推断出在摄入标签的20小时内（在推测的反流之前）发生了8次单独的进食事件，平均需要24.1分钟才能恢复到静息温度。捕食者主要占据浅层（平均 = 2.3米），与76.9%的时间占据水域的标记白鲸重叠≤ 7月，在加拿大波弗特海，经常光顾被标记为Dolly Varden的区域时，距离2.5米。根据标记白鲸的标记漂移和平均位移进行的反向计算表明，捕食可能发生在麦肯齐三角洲以西。结论我们的研究结果为博福特海中Dolly Varden的反捕食者行为和海洋捕食者提供了新的信息。我们首次估计了野生白鲸的进食频率和胃部温度恢复，并为白鲸的浅层觅食行为提供了证据。阐明可能的捕食者，并探索Dolly Varden和白鲸之间的重叠程度，有助于了解博福特海的营养相互作用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Animal Biotelemetry Agricultural and Biological Sciences-Animal Science and Zoology

CiteScore

4.20

自引率

11.10%

发文量

审稿时长

10 weeks

期刊介绍： Animal Biotelemetry is an open access peer-reviewed journal that publishes the results of studies utilizing telemetric techniques (including biologgers) to understand physiological, behavioural, and ecological mechanisms in a broad range of environments (e.g. terrestrial, freshwater and marine) and taxa. The journal also welcomes descriptions and validations of newly developed tagging techniques and tracking technologies, as well as methods for analyzing telemetric data.