西ナイルウイルスの出現と北米の鳥類の大量減少
Shannon L LaDeau1, A Marm Kilpatrick, Peter P Marra
1Smithsonian Migratory Bird Center, National Zoological Park, Washington, DC 20008, USA. ladeaus@si.edu
Nature
|May 18, 2007
まとめ
ウェストナイルウイルス (WNV) は北米の鳥群に重大な影響を及ぼし,アメリカのカラスの45%の減少を含む7種の減少を引き起こしました. 影響を受けたほとんどの種は,WNV以前のレベルに回復しなかった.
科学分野:
- エコロジー エコロジー エコロジー
- 保護生物学の保護生物学
- 野生動物の病気 野生動物の病気
背景:
- 新興感染症は,先住種の保全に重大な脅威をもたらしています.
- 導入された病原体は,種の豊富さ,コミュニティの構成,生態系の機能を劇的に変化させることができます.
- 病気の影響を他の人口動態 (例えば,気候) から区別するには,長期的なデータが必要です.
研究 の 目的:
- ウェストナイルウイルス (WNV) が北米の潜在的宿主となる鳥類20種に及ぼす影響を評価する.
- 病気による変化を特定するために,長期的な調査データを用いて人口軌道を分析する.
主な方法:
- 繁殖鳥調査 (BBS) の26年間のデータを活用した.
- 北米全土の20種の鳥類の集団動向を分析した.
- 西ナイルウイルスの伝播の空間時間的強度と相関する人口変化.
主要な成果:
- 4つの家族から7つの鳥類の集団軌道の有意な変化が観察されました.
- アメリカン・クラウの個体数は,WNVの登場に伴い,最大45%減少した.
- 影響を受けた7種のうち2種のみが,2005年までにWNV以前のレベルに回復した兆候を示した.
結論:
- WNVのような侵入性病原菌は,広い地理的地域における多様な野生生物集団に重大な影響を与える可能性があります.
- この研究は,新しい病気の導入に伴う複雑な生態学的反応を強調しています.
- 長期的なモニタリングは,新たな感染症が生物多様性に及ぼす影響を理解し管理するために不可欠です.
関連する概念動画
Migration
Migration is long-range, seasonal movement from one region or habitat to another. This common strategy, carried out by many different organisms around the world, is an adaptive response that typically corresponds to changes in an organism’s environment, like resource availability or climate. Migrations can involve huge groups of thousands of animals as well as single individuals traveling alone and can range from thousands of kilometers to just a few hundred meters.
Threats to Biodiversity
There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...
Conservation of Small Populations
Small population sizes put a species at extreme risk of extinction due to a lack of variation, and a consequent decrease in adaptability. This weakens the chances of survival under pressures such as climate change, competition from other species, or new diseases. Large populations are more likely to survive pressures such as these, as such populations are more likely to harbor individuals that have genetic variants that are adaptive under new stresses. Small populations are much less likely to...
Conservation of Declining Populations
Conservation of declining population focuses on ways of detecting, diagnosing, and halting a population decline. The approach uses methods to prevent populations from going extinct.
Rabies
Rabies is a lethal zoonotic disease caused by a single-stranded, negative-sense RNA virus of the Lyssavirus genus, within the family Rhabdoviridae. Its primary mode of transmission to humans is through bites or saliva-contaminated scratches from infected mammals such as dogs, bats, raccoons, or foxes. Transmission can also occur if infectious saliva contacts abraded skin or intact mucous membranes, including the conjunctiva.Viral Entry and Early ReplicationOnce introduced at the bite or scratch...
Arboviral Encephalitis
Arboviral encephalitis refers to brain inflammation caused by arthropod-borne viruses, particularly those transmitted through mosquito vectors. Among these, West Nile virus (WNV), a member of the Flaviviridae family, is a significant public health concern. WNV is an enveloped, positive-sense, single-stranded RNA virus. Human infection typically begins when an infected mosquito introduces the virus into the dermis during feeding. The primary transmission cycle involves birds as amplifying hosts...


