Crossbills!

[JayinMN]

Ok, these are a new bird for me. I went out to fill my feeders and I heard some birds calling which I have never heard before so I drove my atv back to my house got the binoculars and camera and headed back. I thought I was seeing crossbills but wasn't sure because I had never seen them before on they were pretty far away. Sure enough thats what they were! Man can they destroy a pine cone is a few seconds. They were way up at the top of some huge red pines. I'm having a pretty good week when it comes to the birds. In the last picture, you have to look closely but I see 6. There are 2 females that blend in pretty good.

[finnbay]

You have been a busy boy!

[jonny_redhorse]

nice Jay!.a great week indeed!...here's a little infi I came across in regard to the crosbill's "twisted beaks"...and why they figure they've evolved that way...kinda interesting!:

Kimberly Coffey, Craig Benkman and Brook Milligan from New Mexico State University, investigated the relationship between pine cones and the foraging efficiency of a finch, the Red Crossbill (Loxia curvirostra).

The researchers removed spines from some open and closed ponderosa pine (Pinus ponderosa) and open Table Mountain pine (Pinus pungens) cones. Other cones were left with their spines intact.

Crossbills were then allowed to eat seeds from the different types of cones, and the time taken for birds to successfully acquire a seed was recorded. In the open pine cones without spines, crossbills could remove a seed much more quickly than when spines were present. It took 18-34% more time for birds to get a seed from the spiny pine cones. They found that spines on pine cones made it difficult for birds to perch on the cone. Spines also impeded crossbills when they tried to reach for seeds between the cone scales.

By studying the evolutionary development of spines on pine cones, the researchers also found that the amount of spine growth has co-evolved with the length of time seeds remain in open pine cones. Therefore, in open pine cones where seeds stay longer, a greater degree of spine growth is observed. This finding answered the question of whether spines developed as a predatory defense, and were not just a welcome side effect.

"We believe," says Benkman, "that Red Crossbills' bodies have adapted over time to become more successful pine cone predators." Modifications such as stronger legs and reshaped mouthparts allow the finches greater perching and seed retrieval skills. Many other predators would have less success obtaining seeds, making the pine cones' defenses even more effective.