The possible relationships between relative brain size and developmental mode and between relative brain size and five measures of the length of the development period were tested across over 1400 species of birds. Using both conventional statistics and phylogenetically based comparative methods, significant differences in relative brain size were detected among modes of development. Across all species, there were significant relationships between relative brain size and each of the following developmental traits: incubation period, age of fledging, duration of postfledging parental care, and total period of parental care. In contrast, the age of first flight was not significantly correlated with relative brain size. The relationships between these five developmental traits and relative brain size varied among developmental modes and orders such that significant relationships were present within some modes and orders but not in others. Thus, developmental differences play a significant role in the evolution of brain-size differences, but the role depends upon the taxonomic level being investigated. This is likely due to the differential lengths of periods of neural and behavioural development in young birds. Our conclusions support the contention of previous studies that developmental differences have played a key role in avian brain evolution.

Evidence is presented to show that the coastal species Pteropus poliocephalus and P. gouldi congregate in large camps from early until late summer. In these large summer camps the young are born and raised, the sexes become associated, and conception occurs. The numbers within these camps are influenced by the availability of blossom in the surrounding area.The adults are normally dispersed during the winter while the immature form winter camps. These camps contain a larger percentage of adults in those winters in which blossom is more abundant.The inland species P. scapulatus forms large camps in early summer but the young are born in autumn when the population is dispersed. Since the food supply of P. scapulatus is less dependable and undergoes greater fluctuations than that of the coastal species, P. scapulatus is more nomadic than P. poliocephalus and P. gouldi.Flying foxes (fruit bats) hang during the day in trees within an area called a "camp", and at night move into the surrounding countryside to feed on nectar, blossoms, and fruit. These daily movements are well documented () but little is known of the seasonal movements of Megachiroptera. Seasonal patterns of movement have been inferred from the progressive occupation of camps over the range of the species, but have not been studied by the recovery of marked individuals.These seasonal movements have been associated with food and climate. Jameson (1909) correlated movements of Epomophorus wahlbergi with the ripening of certain African fruits; Allen, Lang, and Chapin (1917) suggested that the heavy seasonal rains may cause Eidolon helvum to move from the area. Sanborn and Nicholson (1950, p. 316) considered that fluctuation in numbers within camps of Pteropus ornatus in New Caledonia "does not indicate a true migration; rather, simply a seasonal movement instigated by the presence or absence of food".Ratcliffe (1 93 1, p. 26); after examining the Australian species, concluded : "The extensive migrations of the little red fox, P. scapulatus, are almost certainly governed by the blossoming of the so-called hardwood trees. As this is notoriously uncertain, the movements of this species show a considerable irregularity"; and again on p. 24 "P. poliocephalus carries out very regular, seasonal migrations, moving southward in the spring into southern Queensland and New South Wales . . . Beyond the fact (made apparent by the periodic desertion and re-occupation of well-known camps) that this seasonal migration does take place, the available information is scanty".

Endocranial volumes of vertebrate skulls and brain masses are often used interchangeably in comparative analyses of brain size. We test whether endocranial volume can be used as a reliable estimate of brain size in birds by comparing endocranial volumes with brain masses across 82 species using absolute values and with respect to body size. The results of paired tests across all 82 species and within two orders, Passeriformes and Psittaciformes, did not yield a significant difference between the two measures. These results were supported by correlational analyses that showed a significant positive relationship between endocranial volume and brain mass. Unpaired tests within short-tailed shearwaters (Puffinus tenuirostris) and paired tests within budgerigars (Melopsittacus undulatus) also yielded no significant differences between endocranial volume and brain mass. Thus, a combination of interspecific and intraspecific comparisons indicates that endocranial volume does provide a reliable estimate of brain size. Although this may enable more rapid collection of avian brain size data, endocranial volume should be used with caution because it cannot account for seasonal and age-related variation and cannot be used to measure differences in brain structure.

In light of the recent US election, many fear that “fake news” has become a force of enormous reach and influence within the news media environment. We draw on well-established theories of audience behavior to argue that the online fake news audience, like most niche content, would be a small subset of the total news audience, especially those with high availability. By examining online visitation data across mobile and desktop platforms in the months leading up to and following the 2016 presidential election, we indeed find the fake news audience comprises a small, disloyal group of heavy Internet users. We also find that social network sites play an outsized role in generating traffic to fake news. With this revised understanding, we revisit the democratic implications of the fake news crisis.

Despite significant progress in understanding the evolution of the mammalian brain, relatively little is known of the patterns of evolutionary change in the avian brain. In particular, statements regarding which avian taxa have relatively larger brains and brain regions are based on small sample sizes and statistical analyses are generally lacking. We tested whether psittaciforms (parrots, cockatoos and lorikeets) have larger brains and forebrains than other birds using both conventional and phylogenetically based methods. In addition, we compared the psittaciforms to primates to determine if cognitive similarities between the two groups were reflected by similarities in brain and telencephalic volumes. Overall, psittaciforms have relatively larger brains and telencephala than most other non-passerine orders. No significant difference in relative brain or telencephalic volume was detected between psittaciforms and passerines. Comparisons of other brain region sizes between psittaciforms and other birds, however, exhibited conflicting results depending upon whether body mass or a brain volume remainder (total brain volume – brain region volume) was used as a scaling variable. When compared to primates, psittaciforms possessed similar relative brain and telencephalic volumes. The only exception to this was that in some analyses psittaciforms had significantly larger telencephala than primates of similar brain volume. The results therefore provide empirical evidence for previous claims that psittaciforms possess relatively large brains and telencephala. Despite the variability in the results, it is clear that psittaciforms tend to possess large brains and telencephala relative to non-passerines and are similar to primates in this regard. Although it could be suggested that this reflects the advanced cognitive abilities of psittaciforms, similar studies performed in corvids and other avian taxa will be required before this claim can be made with any certainty.