A secretive present from the storm

This delicately striped little sparrow is a member of the American genus Ammodramus, which is Latin for "sand runner". 

Like most members of the genus, the Le Conte's sparrow (Ammodramus leconteii) does indeed scurry rodent like along the ground, as I had the pleasure of witnessing at close quarters. Normally a highly secretive resident of damp grasslands in the middle of the North American continent, this individual was found guzzling seeds by the side of a road in Concord, MA. We think it was probably blown here by a recent storm, and too exhausted to bother escaping from approaching cars or ecstatic birdwatchers.

Tired/ tame Le Conte's sparrow too busy guzzling to wipe its beak

Like many members of the genus, particularly the grasshopper sparrow, the Le Conte's sparrow sounds more like an insect than a bird, with a high-pitched, buzzy trill.

A taxonomic puzzle

This sunny bird, the yellow-breasted chat (Icteria virens), is traditionally classified in the family Parulidae, the New World warblers. However, it is a good deal larger than most of its closest relatives, and its songs are strident and not in the least warbling. In addition, mature males and females are equally colourful, something which cannot be said for most parulids. The only member of its genus, this species has yet to find a taxonomic home. A molecular phylogeny in 2010 ousted the yellow-breasted chat from "the core Parulidae group", but failed to clarify which of several "non-Parulidae outgroup taxa" it is most closely related to.

Yellow-breasted chat (Icteria virens)

References:

Lovette, Irby J.; Perez-Eman, Jorge L.; Sullivan, John P.; et al. 2010 A comprehensive multilocus phylogeny for the wood-warblers and a revised classification of the Parulidae (Ayes)MOLECULAR PHYLOGENETICS AND EVOLUTION  57: 753-770

Inspired by Beatrix Potter

The Morgan Library in New York is currently showing some fabulous letters and art by one of my greatest heros, Beatrix Potter. Potter was especially fond of rabbits, and two of her pets, Peter and Benjamin are the inspiration for her most famous story, "The Tale of Peter Rabbit".

As a testament to the power of artificial selection, rabbits like the Flemish giant can weigh up to 20kg (about 50 pounds).

Flemish Giant Rabbit

Beach mice are subspecies of oldfield mouse (Peromyscus polionotus) that have evolved pale fur to match the pale sand they live on. Hopi Hoekstra and her lab have worked out exactly which mutations in which genes are responsible for this adaptive colouration.

Choctawhatchee beach mouse (Peromyscus polionotus allophrys)

As a Victorian, Potter wouldn't have seen these North American mice in the genus Peromyscus, but I think she would have liked them, with their enormous eyes and relatively infantile proportions.

Evolutionary tricks

The superb fairy-wren (Malurus cyaneus) is a diminutive Australian songbird with some evolutionary tricks that are even more spectacular that the male's plumage.

Male superb fairy-wren (Malurus cyaneus)

Fairy-wrens are parasitised by cuckoos, so one would expect fairy-wren parents to have evolved ways to distinguish their own offspring from cuckoo chicks in the nest. One way fairy-wren mothers seem to do this, is to teach their chicks a special password before the chicks have hatched. Cuckoo eggs are laid later, so their chicks probably don't have time to learn this special password. At any rate, once they hatch, only the fairy-wren chicks are able to reproduce the password in their begging calls, so they get fed, while the cuckoo chicks are often rejected.

Another endearingly complex aspect of fairy-wren biology, is that in spite of their being socially monogamous, about 2/3 of a single clutch are fathered by males other than a female's social mate. What's more, males can be seen courting neighboring females with flowers, while females don't respond to these cuckolding attempts till just before dawn, when they sneak off for a spot of what biologists so fetchingly call "extra-pair copulation". Not surprisingly, sperm competition in these fairy-wrens is superbly high.

References

Colombelli-Negrel, D., Hauber, M. E., Robertson, J., Sulloway, F. J., Hoi, H., Griggio, M. & Kleindorfer, S. 2012. Embryonic Learning of Vocal Passwords in Superb Fairy-Wrens Reveals   Intruder Cuckoo Nestlings. Current Biology, 22, 2155–2160.

Rowley, I., and E. Russell. 1997. Fairy-Wrens and Grasswrens: Maluridae. Oxford Univ. Press, Oxford.