An irruption is not an irruption, it has to do with a specialized bird migration.

Pair of Red Crossbill

Last year we had a irruption of snowy owls, so far this year, it has been winter finches (Pine Grosbeak, Red Crossbill, White-winged Crossbill, Purple Finch, Pine Siskin, Common Redpoll, and Evening Grosbeak) and I have observed all but the Evening Grosbeak.

An irruption is a dramatic, irregular migration of large numbers of birds to areas where they aren’t typically found, possibly at a great distance from their normal ranges. While a few vagrant birds of northern species can appear at Southern feeders and in the year, what characterizes an irruption is the large number of unexpected birds. Irruptions can occur in cycles ranging from 2 to 10 years or they can be completely unpredictable. One of the major reasons for an irruption is a lack of food in the bird's normal wintering ground. This causes the birds to seek areas with more plentiful habitat and they will continue to stay until everything in their normal area returns in the spring.

I had discussed in a previous blog about observing red crossbills in the inability to photograph them along with photographs of white-winged crossbills. Thursdays birding trip allowed me to see the Pine Grosbeak's, but no photograph. At Salisbury beach state reservation, they were many more crossbills present, including both red crossbills and white-winged crossbills, allowing good photo opportunities, in fact, I was able to obtain a picture of both a male red crossbill, and a white-winged crossbill on the same pine cone.