The hybrid bird
The hybrid birdYoav Perlman

Kibbutz Ma'ayan Tzvi in northern Israel received a visit Tuesday from a rare hybrid motacilla. The bird was spotted in the kibbutz’s fish ponds and represents a cross between the citrine wagtail and the western yellow wagtail, which occupy two different genetic groups.

The rare crossbreed bird was discovered in the spot by ornithologist Tzur Magen and spent last winter in the kibbutz. It has returned for this year as well. Shahar Hezkia, a volunteer in the Hof Hacarmel field school of the Society for the Protection of Nature, filmed it flying between water reservoirs and its nest.

Dr. Yoav Perlman, head of the Society's ornithology center, estimates that the bird will spend the current winter at the fish ponds as well. “Only a genetic test will prove this, but from the external appearance, this specimen is similar to documented cases in other parts of the world of crossbreeding between the citrine wagtail and the western yellow wagtail. The sounds it makes are similar to The citrine wagtail, which are completely different from the western yellow wagtail.”

The Society noted that different species of animals generally do not crossbreed. “The reproductive isolation, meaning the inability to create offspring, is one of the scientific ways to differentiate between different species. Nevertheless, nature is not all black and white, and there are many cases in which the borders between species, genera, and morphologies are somewhat blurred.”

“Species that are genetically similar to one another, such as species separated by evolution a relatively short time ago, can produce hybrid offspring if they encounter different populations similar to their species. The bird's parents were presumably a western yellow wagtail and citrine wagtail, two species which intermingle in many nesting areas, from eastern Europe to central Asia,” Dr. Perlman concluded.