Editing Reindeer (section)

=== Predators ===
[[File:Reindeer-on-the-rocks.jpg|thumb|Standing on snow to avoid bloodsucking insects|alt=A herd standing on snow to avoid bloodsucking insects]]

A variety of predators prey heavily on reindeer, including overhunting by people in some areas, which contributes to the decline of populations.<ref name="SARA2014" />

[[Golden eagle]]s prey on calves and are the most prolific hunter on the calving grounds.<ref>Walker, Matt. (20 October 2009) [http://news.bbc.co.uk/earth/hi/earth_news/newsid_8314000/8314558.stm Eagles filmed hunting reindeer] {{webarchive|url=https://web.archive.org/web/20111201065826/http://news.bbc.co.uk/earth/hi/earth_news/newsid_8314000/8314558.stm |date=1 December 2011 }}. BBC News. Retrieved on 16 September 2011.</ref> [[Wolverine]]s will take newborn calves or birthing cows, as well as (less commonly) infirm adults.

[[Brown bear]]s and [[polar bear]]s prey on reindeer of all ages but, like wolverines, are most likely to attack weaker animals, such as calves and sick reindeer, since healthy adult reindeer can usually outpace a bear. The gray [[wolf]] is the most effective natural predator of adult reindeer and sometimes takes large numbers, especially during the winter. Some gray wolf packs, as well as individual [[grizzly bear]]s in Canada, may follow and live off of a particular reindeer herd year-round.<ref name="j2" /><ref name="McLoughlin2003">{{cite journal |last1=McLoughlin |first1=P.D. |last2=Dzus |first2=E. |last3=Wynes |first3=B. |last4=Boutin |first4=Stan |year=2003 |title=Declines in populations of woodland caribou |journal=Journal of Wildlife Management |volume=67 |issue=4 |pages=755–761|doi= 10.2307/3802682 |jstor=3802682}}</ref>

In 2020, scientists on [[Svalbard]] witnessed, and were able to film for the first time, a polar bear attack reindeer, driving one into the ocean, where the polar bear caught up with and killed it.<ref name="Chapman_10/22/2021">{{cite web | last=Chapman | first=Andrew | date=October 22, 2021 | title=Polar bear hunting a reindeer caught on tape for first time. Unusual behavior had been assumed, but never clearly seen | website=[[Science (journal)|Science]] | url=https://www.science.org/content/article/polar-bear-hunting-reindeer-caught-tape-first-time | access-date=October 26, 2021 }}</ref> The same bear successfully repeated this hunting technique the next day. On Svalbard, reindeer remains account for 27.3% in polar bear scats, suggesting that they "may be a significant part of the polar bear's diet in that area".<ref name="Stempniewicz_Kulaszewicz_Aars_10/12/2021">{{cite journal | last1=Stempniewicz | first1=Lech | last2=Kulaszewicz | first2=Izabela | last3=Aars | first3=Jon | title=Yes, they can: polar bears ''Ursus maritimus'' successfully hunt Svalbard reindeer ''Rangifer tarandus platyrhynchus'' | journal=Polar Biology | publisher=Springer Science and Business Media LLC | volume=44 | issue=11 | date=October 12, 2021 | issn=0722-4060 | doi=10.1007/s00300-021-02954-w | pages=2199–2206| bibcode=2021PoBio..44.2199S | s2cid=241470816 | doi-access=free }}</ref>

Additionally, as carrion, reindeer may be scavenged opportunistically by [[Red fox|red]] and [[Arctic fox]]es, various species of [[eagle]]s, [[hawk]]s and [[falcon]]s, and [[common raven]]s.

Bloodsucking insects, such as [[mosquito]]es, [[Black fly|black flies]], and especially the reindeer warble fly or reindeer botfly (''[[Hypoderma tarandi]]'') and the reindeer nose botfly (''[[Cephenemyia trompe]]''),<ref name="Vors-Boyce-2009"/><ref name="Cooper-2014">{{cite journal |last=Cooper |first=Elisabeth J. |title=Warmer Shorter Winters Disrupt Arctic Terrestrial Ecosystems |journal=[[Annual Review of Ecology, Evolution, and Systematics]] |publisher=[[Annual Reviews (publisher)|Annual Reviews]] |volume=45 |issue=1 |date=2014-11-23 |issn=1543-592X |doi=10.1146/annurev-ecolsys-120213-091620 |pages=271–295|doi-access=free }}</ref> are a plague to reindeer during the summer and can cause enough stress to inhibit feeding and calving behaviors.<ref>{{cite web |url= http://www.learner.org/jnorth/tm/caribou/Predators.html |title=Caribou Foes: Natural Predators in the Wilderness |website=Learner.org|access-date=16 September 2011|archive-url=https://web.archive.org/web/20110824104908/http://www.learner.org/jnorth/tm/caribou/Predators.html |archive-date=24 August 2011 |url-status=live}}</ref> An adult reindeer will lose perhaps about {{cvt|1|L}} of blood to biting insects for every week it spends in the tundra.<ref name="Hoare 2009 45"/> The population numbers of some of these predators is influenced by the migration of reindeer.{{Citation needed|date=May 2012}} Tormenting insects keep caribou on the move, searching for windy areas like hilltops and mountain ridges, rock reefs, lakeshore and forest openings, or snow patches that offer respite from the buzzing horde. Gathering in large herds is another strategy that caribou use to block insects.<ref>{{cite web |url=http://www.taiga.net/projectcaribou/pdf/allaboutcaribou.PDF |title=An Educator's Guide to Wild Caribou of North America |publisher=Project Caribou |access-date=17 January 2014 |url-status=usurped |archive-url=https://web.archive.org/web/20130706171742/http://taiga.net/projectcaribou/pdf/allaboutcaribou.PDF |archive-date=6 July 2013}}</ref>

Reindeer are good swimmers and, in one case, the entire body of a reindeer was found in the stomach of a [[Greenland shark]] (''Somniosus microcephalus''), a species found in the far North [[Atlantic]].<ref>{{cite web|url=http://www.postmodern.com/~fi/sharkpics/ellis/greenlan.htm |title=Greenland Shark (''Somniosus microcephalus'') |website=Postmodern.com |access-date=16 September 2011 |archive-url=https://web.archive.org/web/20120510184324/http://www.postmodern.com/~fi/sharkpics/ellis/greenlan.htm |archive-date=10 May 2012 |url-status=dead}}</ref>