Investigations of thermoreception and thermoregulation in birds indicate that thermosensors exist not only in the skin on the body but also in the skin around the face, the thoracic brood patch (the area used for egg incubation), and the beak.
The mate choice tests with adult birds indicate that nutritional conditions during the period of song learning, brain and gonad development, and moult into adult plumage have persisting effects on male attractiveness.
Experiments with captive birds indicate that the availability of calcium [15]; see also [16], phenylalanine and tyrosine [17] could be limiting for the production of melanins see also [18].
Lawrence M. Witmer, a paleontologist at Ohio University who conducts other Archaeopteryx research, said that he was not surprised to learn that the species was "not fully avian," but that it had many features seen in later birds, indicating that it had not been displaced as "a very basal member" of the avian family tree.
The fact that the leading-edge vortex also enhances the flight of insects, bats (ScienceNOW, 10 May 2007), and probably birds indicates that it is an important universal mechanism for generating high lift forces, says Anders Hedenström, a theoretical ecologist at Lund University in Sweden.
The fact that the birds put on weight during their foraging trips and returned after a similar period to other, control birds, indicates that the TDRs had little impact on their performance.
No significant difference was found between summer and winter birds indicating that they were carrying the additional fat at no additional energetic cost (Figure 1b, ANCOVA: season, F1,64 = 2.81, r2 = 0.025, p = 0.100; U, F1,64 = 47.7, r2 = 0.42, p<0.001).
When comparing the total number of birds infested with infected ticks compared to the total number of collected birds, the figures were 59/6174 = 1% in ground-foraging birds and 18/7085 = 0.25% in other birds indicating that the former group of birds has a higher risk of exposure to ticks as a result of their feeding habits [Fisher's exact test, p<0.001].
The clear directional compensation found even in experimentally displaced birds indicates that first-year birds can also possess the ability to correct for displacement in some circumstances, possibly involving either some primitive form of true navigation, or 'sign posts', but the cues used for this are highly speculative.
Reed et al. demonstrated, for a highly pathogenic H5N1 strain, that the reduction of the pH of HA activation increased the viral shedding from the trachea but not from the cloaca of infected birds, indicating that the threshold pH of HA conformational change could be important for host and/or tissue tropism [19].
As expected, no differences in area X FoxP2 levels were observed between sham operated and untreated birds, indicating that the surgery itself had no effect (mean±SEM levels in area X relative to levels in the outlying striatum, Sham vs. Untreated – 3' probe: 1.05±0.06 vs. 1.09±0.03, p = 0.38; mid-probe: 1.05±0.04 vs. 1.11±0.04, p = 0.19).
