Approximately, one-third of those who develop major depression will have a poor response to treatment and over time can become treatment resistant. Intestinal dysbiosis has been implicated in depression with systemic inflammation and vagal and enteric nerve impairment. We report on a sequel pilot study (n = 12) with a combination probiotics/magnesium orotate formulation adjuvant administered with SSRIs for treatment resistant depression. At the end of an 8-week intervention mean changes for depression scores and quality of life in the group was clinically significantly improved (p < 0.001) with all but 4 participants experiencing a benefit. An intestinal anti-inflammatory response was suggested. At 16-weeks follow-up while still on SSRI medications, the group had relapsed after cessation of the test intervention.

There are numerous observational studies on intraspecific variation in avian nest building and a single experimental manipulation. The general consensus is that birds build nests in response to environmental conditions, but it is not clear whether such flexibility in nest building is reproductively advantageous. To test the relationship between building flexibility and reproductive success, we allowed captive zebra finches to build their first nest, using string, and to breed in temperature-controlled rooms held at 14 or 30 °C. Once the offspring had fledged, we returned half the pairs to breed at the same temperature while half the pairs were switched to the alternative temperature. We provided all pairs with string and left them to build and breed a second time. For their first nest, pairs that built at 14 °C used more string than did pairs that built at 30 °C, and pairs that bred successfully built a nest with more string than did unsuccessful pairs. When pairs built their second nest, however, temperature no longer explained the number of pieces of string they used; rather, irrespective of the ambient temperature, pairs that had successfully produced young from their first nest used the same amount of string for their second nest, whereas those that had failed to reproduce with their first nest used more string. These latter pairs were then more likely to reproduce successfully. Ambient temperature, therefore, did affect the nest the pairs built but only in the absence of reproductive experience.

Variation in animal material technology, such as tool use and nest construction, is thought to be caused, in part, by differences in the early-life socio-ecological environment—that is, who and what is around—but this developmental hypothesis remains unconfirmed. We used a tightly controlled developmental paradigm to determine whether adult and/or raw-material access in early life shape first-time nest construction in laboratory-bred zebra finches Taeniopygia guttata at sexual maturity. We found that juvenile access to both an unrelated adult and raw material of one color led to a majority preference (75%) by novice builders for this color of material over that for either natal-nest or novel-colored material, whereas a lack of juvenile access to both an unrelated adult and raw material led to a 4- and nearly 3-fold reduction in the speed at which novice builders initiated and completed nest construction, respectively. Contrary to expectation, neither the amount of time juveniles nor their adult groupmate spent handling the raw material appear to drive these early-life effects on zebra finches’ first-time nest construction, suggesting that adult presence might be sufficient to drive the development of animal material technology. Together these data show that the juvenile socio-ecological environment can trigger variation in at least two critical aspects of animal material technology (material preference and construction speed), revealing a potentially powerful developmental window for technological advancement. Thus, to understand selection on animal material technology, the early-life environment must be considered.

The materials that birds use to build their nests have a profound effect on nest quality and consequently on the builder's reproductive success. Given that the common method to quantify nest materials by dismantling nests takes time and limits study species, we developed a nondestructive and much quicker method for quantifying nest materials using nest photographs. Using our photographic method, the proportions of the main materials in 45 Blue Tit Cyanistes caeruleus and 20 Dartford Warbler Sylvia undata nests, including grass, heather and moss, matched those found by dismantling the nests, but the proportions of rarer animal-derived materials differed between the two methods. Provided that there is an initial calibration with the dismantling method, the photographic method offers two key advantages: a reduction in the time it takes to quantify the major components of nests, and application to previously inaccessible data, including museum collections. Together, these advantages encourage further study of nesting materials and enable a better understanding of avian nest diversification.

Nest building consists of a series of motor actions, which are concomitant with activity in regions of the anterior motor pathway, the social behaviour network and the reward circuity in nest building adult male zebra finches (Taeniopygia guttata). It is not clear, however, whether this activity is due to nest building, collection and/or manipulation of nest material. To identify which areas of the brain are specifically involved, we used immunohistochemistry to quantify the immediate early gene c-fos in male zebra finches that were nest building (Building), birds given a nestbox but could interact only with tied down nest material (Fixed), and birds that were not given a nestbox or nest material (Control). We investigated the following brain regions: the anterior motor pathway (anterior ventral mesopallium (AMV), anterior nidopallium (AN), anterior striatium (ASt)), areas of the social behaviour network (bed nucleus of the stria terminalis, dorsomedial sub division (BSTmd), lateral septum (LS)), the dopaminergic reward circuitry (ventral tegmental area (VTA)) and the cerebellum. We found that there was greater Fos-ir expression in the BSTmd, LS and AMV with increased material deposition; in LS, AMV ASt and folia VI with increased material carrying; in LS, AMV and ASt with increased nest material tucking; and in LS and all folia (except folium VIII) with increased tugging at tied down material. These data confirm a functional role for areas of the anterior motor pathway, social behaviour network and the cerebellum in nest material collection and manipulation by birds.