英検準1級の野生動物・生物多様性の長文【無料3題15問】｜動物の道路横断・湿地・渡り鳥

英検準1級の野生動物・生物多様性の長文では、観測された回数と動物の個体数を混同しないことが重要です。慶英会は動物の道路横断、湿地の回復、渡り鳥の市民調査を題材に、オリジナル長文3篇と4択15問、追加英文9問、段落別日本語解説、全文の解答を公開します。

日本英語検定協会の準1級試験内容では自然・環境などを含む題材を扱い、長文内容一致は7問です。本記事の3長文15問は慶英会の独自教材であり、架空の地域・調査の設定です。公式過去問や実際の生物調査の結果ではありません。

結論｜自然・生態系の英文を読む5原則

• 撮影された数と動物の個体数を分ける。
• 卵・成体・生息地の状態は異なる測定指標として扱う。
• 人間が観察する場所・時間・天候の違いによって記録が偏る可能性を確認する。
• 自然保護と交通安全・農地利用の両方を考慮する。
• 一回の試行で恒久的な成果を証明したと断定しない。

演習方法｜初見英文→根拠→日本語→復習

まず各長文を英語だけで読み、4択5問を解いてください。答え合わせでは正答の本文根拠を指摘し、誤答の言い過ぎ・主体の違い・時点の誤りを確認します。その後、段落ごとの日本語解説を読み、追加の9文をmay・couldなどの限定を保って訳します。

独自長文1｜野生動物の道路横断を支える通路（約231語）

英文・第1段落

In a fictional mountain region, a highway divided areas used by deer and smaller mammals. Drivers sometimes reported animals crossing the road, and conservation groups suggested building a passage beneath the highway. Some supporters thought a passage would immediately prevent every collision. Road engineers responded that different species might not use the same type of structure, and that fences and the passage’s location would influence its effectiveness. The district decided to evaluate an existing drainage tunnel before paying for an entirely new bridge.

英文・第2段落

Researchers installed cameras near the tunnel and collected reports of animal tracks. They recorded several visits, but they warned that the number of photographs could not be treated as the number of individual animals. The same deer might appear repeatedly, while other species could avoid the tunnel. Farmers also worried about access to their fields during construction and the cost of maintaining nearby fencing. To account for these issues, officials compared camera images with other observations instead of relying on a single measure.

英文・第3段落

Eventually, the district chose to improve the existing passage and continue monitoring its use across seasons. It also planned to examine traffic records for changes in animal-vehicle collisions. Officials stressed that the aim was to reduce risks while maintaining wildlife movement, not to guarantee the disappearance of every accident. The success of the work would have to be judged using both ecological and road-safety evidence.

4択内容一致・独自5問

Q1. Why was the passage proposed?

1. To eliminate all farming.
2. To allow animals to move between areas divided by a highway.
3. To replace all vehicles.
4. To close every mountain path.

Q2. Why did engineers avoid promising that every collision would end?

1. Animals would never enter tunnels.
2. No highway had been constructed.
3. Different species and locations could affect use of the passage.
4. Fences were not allowed anywhere.

Q3. Why couldn’t the photographs establish the number of individual animals?

1. The same animal might appear more than once.
2. Every photograph was blurred.
3. The cameras had been removed.
4. The records were never reviewed.

Q4. What did the district ultimately decide?

1. To build every proposed bridge immediately.
2. To stop monitoring the road.
3. To remove all fencing.
4. To improve an existing passage and continue evaluating it.

Q5. Which evidence was important for evaluating success?

1. Only tourist numbers.
2. Both animal movement and traffic safety records.
3. Only the cost of a new bridge.
4. Only a single day’s photographs.

段落別の日本語解説

第1段落：架空の山間地域では高速道路がシカや小型哺乳類の生息地を分断した。保護団体は通路の整備を提案したが、通路を造ればすべての衝突事故を防げるわけではない。動物の種類、通路の位置、柵などによって使われ方が違うため、新たな橋を造る前に既存トンネルを検証することにした。

第2段落：研究者はトンネルにカメラを設置して足跡も調べた。撮影枚数が個体数を示すわけではない。同じシカが何度も写ることもある。工事中の農道への通行や柵の維持費も検討し、複数の情報源を比較した。

第3段落：地域は既存通路を改修して季節ごとの利用状況と交通事故記録を調べることにした。動物の移動を守り、事故リスクを下げるのが目的であり、事故ゼロを保証するものではない。

重要語彙・表現

• wildlife crossing：野生動物用の横断通路
• habitat：生息地
• drainage tunnel：排水用トンネル
• fencing：柵の設置
• collision：衝突

長文1・全5問の正解と本文根拠

Q1 正解B：To allow animals to move between areas divided by a highway.。本文根拠：divided areas used by deer … suggested building a passage。解説：生息地の分断への対策。

Q2 正解C：Different species and locations could affect use of the passage.。本文根拠：different species might not use the same type of structure。解説：通路の効果は種類・場所などによって異なる。

Q3 正解A：The same animal might appear more than once.。本文根拠：same deer might appear repeatedly。解説：撮影回数を個体数として数えられない。

Q4 正解D：To improve an existing passage and continue evaluating it.。本文根拠：improve the existing passage and continue monitoring。解説：既存設備の改善と追加観測。

Q5 正解B：Both animal movement and traffic safety records.。本文根拠：both ecological and road-safety evidence。解説：生態系と交通安全の両方を評価する。

追加・論理と限定の英文3問

応用1：the same deer might appear repeatedly

応用2：instead of relying on a single measure

応用3：not to guarantee the disappearance of every accident

追加3問の模範訳

応用1 解答：同じシカが繰り返し写る可能性がある。

応用2 解答：一つの指標だけに頼るのでなく。

応用3 解答：すべての事故がなくなると保証するのではない。

独自長文2｜湿地を回復させると両生類は増えるか（約233語）

英文・第1段落

A fictional town planned to restore a wetland that had been drained many years earlier. Volunteers hoped that keeping water in selected areas would create habitats suitable for amphibians, insects, and plants. However, nearby farmers used paths and drainage channels around the wetland, and they worried that unexpected flooding could disrupt their work. The project team therefore began by studying the movement of water and the effects of different layouts rather than assuming that increasing water levels everywhere would always be beneficial.

英文・第2段落

Researchers measured seasonal water levels and recorded amphibian egg clusters at several locations. They cautioned that the number of clusters was not the same as the number of adult animals, because breeding conditions and the visibility of eggs varied. Volunteers were asked to follow consistent observation methods and record days when bad weather limited their work. The team also considered the expense of maintaining water channels that remained necessary for agricultural activities.

英文・第3段落

In the first trial, several locations held water for longer periods, and more egg clusters were observed at certain sites. The researchers welcomed these signs but warned that one breeding season was insufficient to prove sustainable population growth. They planned to investigate animal survival, changes in habitat, and possible effects on adjacent farmland over several years. The town’s goal was to improve ecological conditions while respecting existing land uses, not to declare an immediate and complete restoration of biodiversity.

4択内容一致・独自5問

Q6. Why were farmers concerned about the project?

1. They wanted all plants removed.
2. The region had no water.
3. Water changes could disrupt field access or work.
4. No one had planned any restoration.

Q7. What did the researchers measure?

1. Seasonal water levels and amphibian egg clusters.
2. Only tourist numbers.
3. Every animal’s exact age.
4. Only crop prices.

Q8. Why did researchers refuse to equate egg clusters with adult animals?

1. Eggs were all artificial.
2. Breeding conditions and visibility could affect the number found.
3. No animals laid eggs in the wetland.
4. All adults had been individually identified.

Q9. What was uncertain after the first season?

1. Whether a trial had taken place.
2. Whether the town had farmland.
3. Whether any water had been observed.
4. Whether the changes produced sustainable population growth.

Q10. What did the town seek to balance?

1. Farming with permanent road closure.
2. Tourism with exam schedules.
3. Ecological improvement with existing land uses.
4. Observations with a ban on all volunteers.

段落別の日本語解説

第1段落：架空の町は以前排水された湿地を回復させ、両生類・昆虫・植物に適した生息地を増やそうとした。しかし農家は周囲の道や排水路を利用するため、水を増やすことによる予期せぬ浸水を心配した。そこで水の移動と配置を調べてから試行することにした。

第2段落：研究者は季節ごとの水位と両生類の卵塊数を調べた。ただし卵塊数は成体数と同一ではなく、産卵条件や見つけやすさによって異なる。観測法を統一し、悪天候で調査できない日も記録した。農作業で必要な排水路の管理費も検討した。

第3段落：初期試行では長く水が残る場所が増え、卵塊も一部で多く見つかった。しかし1回の繁殖期だけで持続的な個体群増加は証明できない。生存率・生息地・周辺農地への影響を長期間調べ、自然保護と土地利用を両立させる方針とした。

重要語彙・表現

• wetland：湿地
• amphibian：両生類
• egg cluster：卵の塊
• drainage channel：排水路
• restoration：回復・復元

長文2・全5問の正解と本文根拠

Q6 正解C：Water changes could disrupt field access or work.。本文根拠：unexpected flooding could disrupt their work。解説：農作業への影響が懸念された。

Q7 正解A：Seasonal water levels and amphibian egg clusters.。本文根拠：measured seasonal water levels and recorded … egg clusters。解説：水位と卵塊を観測した。

Q8 正解B：Breeding conditions and visibility could affect the number found.。本文根拠：breeding conditions and the visibility of eggs varied。解説：見つかる卵塊数は成体数と一致しない。

Q9 正解D：Whether the changes produced sustainable population growth.。本文根拠：one breeding season was insufficient to prove sustainable population growth。解説：持続的な増加は未確認。

Q10 正解C：Ecological improvement with existing land uses.。本文根拠：improve ecological conditions while respecting existing land uses。解説：自然と農地の両立。

追加・論理と限定の英文3問

応用4：rather than assuming that increasing water levels everywhere would always be beneficial

応用5：the number of clusters was not the same as the number of adult animals

応用6：insufficient to prove sustainable population growth

追加3問の模範訳

応用4 解答：水位を上げることがどこでも有益だと決めつけずに。

応用5 解答：卵塊数は成体の個体数と同一ではない。

応用6 解答：持続的な個体群の増加を証明するには不十分。

独自長文3｜渡り鳥の市民調査で数字を読む（約230語）

英文・第1段落

A fictional bird conservation organization asked volunteers to record migrating birds during spring and autumn. The project extended across a region that professional scientists could not visit every day. Participants entered observations using a simple online form and received instructions on identifying species. As the database grew, some supporters celebrated the larger number of reports as evidence that more birds were arriving. Researchers advised caution: a rise in reports could also reflect changes in where and when people watched.

英文・第2段落

Volunteers often visited easily accessible parks on weekends, while isolated marshes were observed less frequently. Bad weather reduced the number of people outside, even when birds might still have been present. The researchers therefore asked volunteers to record their observation time and occasions when they saw no birds. These details could help distinguish actual patterns of migration from the unequal effort spent looking for birds. Experienced volunteers were also invited to visit less frequently surveyed locations when doing so was safe.

英文・第3段落

After comparing several migration seasons, the researchers identified areas that deserved more detailed study. They did not announce that birds had permanently changed their routes, because the available information remained incomplete. Instead, the organization published maps with explanations of its methods and uncertainties. Staff thanked volunteers for widening the coverage of the research but emphasized that a large number of submissions was no substitute for reliable and carefully documented observations.

4択内容一致・独自5問

Q11. What was a benefit of the volunteer project?

1. It increased the geographical coverage of observations.
2. It eliminated the need for all researchers.
3. It guaranteed correct identification every time.
4. It proved every population was growing.

Q12. Why could report numbers be misleading?

1. Every report was necessarily false.
2. No birds were present.
3. The location and frequency of human observation could change.
4. The project had no online form.

Q13. Why did volunteers record occasions when no birds were found?

1. To prevent future surveys.
2. To help describe observation effort and interpret the data.
3. To increase entrance fees.
4. To avoid visiting parks.

Q14. What did the researchers identify after several seasons?

1. Permanent proof of completely different migration routes.
2. A ban on public birdwatching.
3. A list of every bird alive.
4. Locations where further investigation would be useful.

Q15. What lesson did the staff emphasize?

1. Large submission numbers alone are insufficient without reliable records.
2. Every volunteer report can be counted as a different bird.
3. Weather never affects observation.
4. Uncertainty should never be mentioned.

段落別の日本語解説

第1段落：架空の野鳥保全団体は春と秋に渡り鳥の目撃を報告してもらう市民参加型の調査を始めた。専門家だけでは毎日回れない広い範囲を調べられるが、報告数の増加がそのまま渡り鳥の増加を示すとは限らない。観察する人や場所・時期が変わった可能性もある。

第2段落：参加者は行きやすい公園を週末に訪れる傾向があり、遠い湿地の観察は少ない。悪天候では人が外へ出る回数も減る。そのため観察時間と鳥を見なかった日も記録し、鳥そのものの変化と人間側の観察努力の偏りを分けようとした。安全な場合は調査の少ない地域にも出向いた。

第3段落：複数の渡りの季節を比較して追加調査する場所を見つけたが、渡りの経路が恒久的に変わったとは断定しなかった。観測方法と限界を地図とともに公表し、投稿数だけでなく記録の信頼性を重視した。

重要語彙・表現

• migration：渡り
• sighting：目撃記録
• citizen science：市民参加型の科学調査
• marsh：湿地
• observation effort：観測努力量

長文3・全5問の正解と本文根拠

Q11 正解A：It increased the geographical coverage of observations.。本文根拠：extended across a region that professional scientists could not visit every day。解説：観測範囲を広げる利点。

Q12 正解C：The location and frequency of human observation could change.。本文根拠：rise in reports … changes in where and when people watched。解説：観察者の行動も記録数に影響する。

Q13 正解B：To help describe observation effort and interpret the data.。本文根拠：record their observation time and occasions when they saw no birds。解説：観察の条件と非検出を残す。

Q14 正解D：Locations where further investigation would be useful.。本文根拠：areas that deserved more detailed study。解説：追加調査すべき場所を見つけた。

Q15 正解A：Large submission numbers alone are insufficient without reliable records.。本文根拠：no substitute for reliable and carefully documented observations。解説：データ量と信頼性を区別。

追加・論理と限定の英文3問

応用7：a rise in reports could also reflect changes in where and when people watched

応用8：distinguish actual patterns … from the unequal effort

応用9：a large number of submissions was no substitute for reliable … observations

追加3問の模範訳

応用7 解答：報告増加は人間の観察場所・時間の変化も反映し得る。

応用8 解答：実際の変化と観察努力の違いを区別する。

応用9 解答：大量投稿は信頼できる観測に代わるものではない。

3分野の観測と結論を比較する

• 動物横断路：撮影回数と個体数を区別し、交通事故・通路利用を別々に調べる。
• 湿地回復：卵塊が増えても長期的な生存・個体群増加が確定したわけではない。
• 渡り鳥調査：報告数の多さと実際の鳥の数を分け、観察努力量を記録する。

7日間の復習計画

1. 1日目：3長文・15問を初見で解く。
2. 2日目：動物の通路について撮影回数と個体数の違いを説明。
3. 3日目：湿地について水位・卵塊・成体の関係を整理。
4. 4日目：市民科学で人間の観察条件を説明。
5. 5日目：追加9問を正確に訳す。
6. 6日目：3長文をそれぞれ英語3文で要約する。
7. 7日目：公式過去問で自然・環境分野へ応用する。

よくある質問

生物学の専門知識がなくても準1級の長文は解けますか？

本文にある定義と因果、測定の限界を優先して読めば解答できます。一般知識だけで選択肢を決めず、根拠となる英文を探してください。

写真に10回写ったら10匹いるという意味ですか？

必ずしもそうではありません。同じ個体が繰り返し写った可能性があるため、撮影回数をそのまま個体数とは扱えません。

この調査は実在するデータですか？

いいえ。慶英会が英語学習のために作った架空の調査と説明文です。実際の生態系調査の結果や政策効果を断定するものではありません。

独自15問の正答率から英検準1級の合否を判定できますか？

できません。協会の長文内容一致は7問で、この記事は学習量を増やすために3長文15問を収録しています。CSEスコアに直接換算できません。

次に学ぶ関連教材と慶英会の無料体験

食料・農業の独自3長文15問／環境・エネルギーの独自3長文15問／科学・医療の独自3長文15問／準1級無料教材一覧。

慶英会では英検準1級の自然・科学分野を題材にした英文も、語彙・構文・設問根拠まで確認する個別指導を行っています。最大1か月完全無料体験・学習相談はこちら。

参考にした主な公式情報

日本英語検定協会｜準1級の試験内容／日本英語検定協会｜準1級過去問。

公式情報確認：2026年10月28日。独自長文3篇・4択15問・追加9問・和訳・根拠解説は慶英会が制作しました。