Do reindeer aggregate on snow patches to reduce harassment by parasitic flies or to thermoregulate?

During warm, sunny days (Max. temp. 22 °C to 25 °C) C02-baited traps operated at sites on and off snow patches (SP's) in subarctic Norway caught significantly fewer culicids, simuliids and tabanids on snow in both 1985 and 1987. However, for overnight catches (18.30 - 07.30 h) there was no sign...

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Published in:Rangifer
Main Authors: John R. Anderson, Arne C. Nilssen
Format: Article in Journal/Newspaper
Language:English
Published: Septentrio Academic Publishing 1998
Subjects:
Online Access:https://doi.org/10.7557/2.18.1.1369
https://doaj.org/article/b867b3f302c94397bba287e43b699a3f
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spelling ftdoajarticles:oai:doaj.org/article:b867b3f302c94397bba287e43b699a3f 2023-05-15T18:03:58+02:00 Do reindeer aggregate on snow patches to reduce harassment by parasitic flies or to thermoregulate? John R. Anderson Arne C. Nilssen 1998-02-01T00:00:00Z https://doi.org/10.7557/2.18.1.1369 https://doaj.org/article/b867b3f302c94397bba287e43b699a3f EN eng Septentrio Academic Publishing https://septentrio.uit.no/index.php/rangifer/article/view/1369 https://doaj.org/toc/1890-6729 doi:10.7557/2.18.1.1369 1890-6729 https://doaj.org/article/b867b3f302c94397bba287e43b699a3f Rangifer, Vol 18, Iss 1 (1998) reindeer Rangifer tarandus thermoregulation parasitic fly harassment anti-fly behaviour videotape analyses Animal culture SF1-1100 article 1998 ftdoajarticles https://doi.org/10.7557/2.18.1.1369 2022-12-31T05:51:07Z During warm, sunny days (Max. temp. 22 °C to 25 °C) C02-baited traps operated at sites on and off snow patches (SP's) in subarctic Norway caught significantly fewer culicids, simuliids and tabanids on snow in both 1985 and 1987. However, for overnight catches (18.30 - 07.30 h) there was no significant difference in the number of culicids caught on versus off SP's. Analysis of videotapes taken in 1987 showed that defensive anti-fly behaviors of reindeer on and off SP's remained low (< 1/4 min) throughout the day. Based on reindeer anti-fly behaviors, harassment was greatest from 10.30 to 12.30 h (Norwegian Standard Time), but reindeer continued to aggregate on SP's while anti-fly behaviors were lowest (13.30 to 20.00 h). Groups of > 150 animals often occupied the entire surface of a snow patch. At the fly densities and climatic conditions encountered it seemed apparent that reindeer intermittently used SP's primarily to thermoregulate following periods of foraging. Almost all reindeer remained on SP's from 11.00 to 12.30 h, but at other times between 08.00 and 19 00 h about half the herd (ca. 800 animals) foraged for about an hour while the other half aggregated on SP's. However, by 20.00 h, during the cooler period when trap catches of mosquitoes were increasing, almost all reindeer had moved off SP's. The small decreases in anti-fly defensive behaviors observed for reindeer on SP's versus animals foraging in snow-free areas indicated that their presence on SP's may have resulted in a minor, coincidental reduction in harassment. Significantly more tabanids were caught during the morning trapping period than at other times, and significantly more mosquitoes were caught during the evening/overnight trapping period than at other times. Article in Journal/Newspaper Rangifer Rangifer tarandus Subarctic Directory of Open Access Journals: DOAJ Articles Norway Rangifer 18 1 3
institution Open Polar
collection Directory of Open Access Journals: DOAJ Articles
op_collection_id ftdoajarticles
language English
topic reindeer
Rangifer tarandus
thermoregulation
parasitic fly harassment
anti-fly behaviour
videotape analyses
Animal culture
SF1-1100
spellingShingle reindeer
Rangifer tarandus
thermoregulation
parasitic fly harassment
anti-fly behaviour
videotape analyses
Animal culture
SF1-1100
John R. Anderson
Arne C. Nilssen
Do reindeer aggregate on snow patches to reduce harassment by parasitic flies or to thermoregulate?
topic_facet reindeer
Rangifer tarandus
thermoregulation
parasitic fly harassment
anti-fly behaviour
videotape analyses
Animal culture
SF1-1100
description During warm, sunny days (Max. temp. 22 °C to 25 °C) C02-baited traps operated at sites on and off snow patches (SP's) in subarctic Norway caught significantly fewer culicids, simuliids and tabanids on snow in both 1985 and 1987. However, for overnight catches (18.30 - 07.30 h) there was no significant difference in the number of culicids caught on versus off SP's. Analysis of videotapes taken in 1987 showed that defensive anti-fly behaviors of reindeer on and off SP's remained low (< 1/4 min) throughout the day. Based on reindeer anti-fly behaviors, harassment was greatest from 10.30 to 12.30 h (Norwegian Standard Time), but reindeer continued to aggregate on SP's while anti-fly behaviors were lowest (13.30 to 20.00 h). Groups of > 150 animals often occupied the entire surface of a snow patch. At the fly densities and climatic conditions encountered it seemed apparent that reindeer intermittently used SP's primarily to thermoregulate following periods of foraging. Almost all reindeer remained on SP's from 11.00 to 12.30 h, but at other times between 08.00 and 19 00 h about half the herd (ca. 800 animals) foraged for about an hour while the other half aggregated on SP's. However, by 20.00 h, during the cooler period when trap catches of mosquitoes were increasing, almost all reindeer had moved off SP's. The small decreases in anti-fly defensive behaviors observed for reindeer on SP's versus animals foraging in snow-free areas indicated that their presence on SP's may have resulted in a minor, coincidental reduction in harassment. Significantly more tabanids were caught during the morning trapping period than at other times, and significantly more mosquitoes were caught during the evening/overnight trapping period than at other times.
format Article in Journal/Newspaper
author John R. Anderson
Arne C. Nilssen
author_facet John R. Anderson
Arne C. Nilssen
author_sort John R. Anderson
title Do reindeer aggregate on snow patches to reduce harassment by parasitic flies or to thermoregulate?
title_short Do reindeer aggregate on snow patches to reduce harassment by parasitic flies or to thermoregulate?
title_full Do reindeer aggregate on snow patches to reduce harassment by parasitic flies or to thermoregulate?
title_fullStr Do reindeer aggregate on snow patches to reduce harassment by parasitic flies or to thermoregulate?
title_full_unstemmed Do reindeer aggregate on snow patches to reduce harassment by parasitic flies or to thermoregulate?
title_sort do reindeer aggregate on snow patches to reduce harassment by parasitic flies or to thermoregulate?
publisher Septentrio Academic Publishing
publishDate 1998
url https://doi.org/10.7557/2.18.1.1369
https://doaj.org/article/b867b3f302c94397bba287e43b699a3f
geographic Norway
geographic_facet Norway
genre Rangifer
Rangifer tarandus
Subarctic
genre_facet Rangifer
Rangifer tarandus
Subarctic
op_source Rangifer, Vol 18, Iss 1 (1998)
op_relation https://septentrio.uit.no/index.php/rangifer/article/view/1369
https://doaj.org/toc/1890-6729
doi:10.7557/2.18.1.1369
1890-6729
https://doaj.org/article/b867b3f302c94397bba287e43b699a3f
op_doi https://doi.org/10.7557/2.18.1.1369
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