"life bird" meaning in English

{
  "forms": [
    {
      "form": "life birds",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "life bird (plural life birds)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Birdwatching",
          "orig": "en:Birdwatching",
          "parents": [
            "Hobbies",
            "Recreation",
            "Human activity",
            "Human behaviour",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A bird species seen for the first time by a birder who is keeping a list of all the species he or she has ever seen."
      ],
      "id": "en-life_bird-en-noun-acQUjeMJ",
      "links": [
        [
          "birdwatching",
          "birdwatching#Noun"
        ],
        [
          "bird",
          "bird"
        ],
        [
          "species",
          "species"
        ],
        [
          "birder",
          "birder"
        ]
      ],
      "raw_glosses": [
        "(birdwatching) A bird species seen for the first time by a birder who is keeping a list of all the species he or she has ever seen."
      ],
      "related": [
        {
          "word": "life list"
        }
      ],
      "synonyms": [
        {
          "word": "lifer"
        }
      ],
      "topics": [
        "biology",
        "birdwatching",
        "natural-sciences",
        "ornithology"
      ]
    }
  ],
  "word": "life bird"
}

{
  "forms": [
    {
      "form": "life birds",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "life bird (plural life birds)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "life list"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "en:Birdwatching"
      ],
      "glosses": [
        "A bird species seen for the first time by a birder who is keeping a list of all the species he or she has ever seen."
      ],
      "links": [
        [
          "birdwatching",
          "birdwatching#Noun"
        ],
        [
          "bird",
          "bird"
        ],
        [
          "species",
          "species"
        ],
        [
          "birder",
          "birder"
        ]
      ],
      "raw_glosses": [
        "(birdwatching) A bird species seen for the first time by a birder who is keeping a list of all the species he or she has ever seen."
      ],
      "topics": [
        "biology",
        "birdwatching",
        "natural-sciences",
        "ornithology"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "lifer"
    }
  ],
  "word": "life bird"
}