Eviction-driven infanticide and sexually selected adoption and infanticide in a neotropical parrot.

Infanticide and adoption have been attributed to sexual selection, where an individual later reproduces with the parent whose offspring it killed or adopted. While sexually selected infanticide is well known, evidence for sexually selected adoption is anecdotal. We report on both behaviors at 346 nests over 27 y in green-rumped parrotlets (Forpus passerinus) in Venezuela. Parrotlets are monogamous with long-term pair bonds, exhibit a strongly male-biased adult sex ratio, and nest in cavities that are in short supply, creating intense competition for nest sites and mates. Infanticide attacks occurred at 256 nests in two distinct contexts: 1) Attacks were primarily committed by nonbreeding pairs (69%) attempting to evict parents from the cavity. Infanticide attacks per nest were positively correlated with population size and evicting pairs never adopted abandoned offspring. Competition for limited nest sites was a primary cause of eviction-driven infanticide, and 2) attacks occurred less frequently at nests where one mate died (31%), was perpetrated primarily by stepparents of both sexes, and was independent of population size. Thus, within a single species and mating system, infanticide occurred in multiple contexts due to multiple drivers. Nevertheless, 48% of stepparents of both sexes adopted offspring, and another 23% of stepfathers exhibited both infanticide and long-term care. Stepfathers were often young males who subsequently nested with widows, reaching earlier ages of first breeding than competitors and demonstrating sexually selected adoption. Adoption and infanticide conferred similar fitness benefits to stepfathers and appeared to be equivalent strategies driven by limited breeding opportunities, male-biased sex ratios, and long-term monogamy.

A review of commercial captive breeding of parrots as a supply-side intervention to address unsustainable trade.

The volume and scale of commercial captive breeding of parrots have grown dramatically in recent decades. Although it has been proposed, and is often assumed, that captive breeding can reduce pressure on wild populations, there has been little scrutiny of the scale, viability, or impacts of captive breeding to prevent overexploitation among parrots, compared with similar approaches in other threatened taxa, such as pangolins or tigers. We reviewed the primary and gray literature to quantitatively and qualitatively evaluate evidence concerning 5 criteria, established a priori, for commercial captive breeding of parrots as an effective supply-side intervention. We focused on a sample of 16 threatened parrot species that are heavily traded or for which unsustainable trade has been a factor in the decline of wild populations, representing a range of taxonomic groups, life histories, and native regions. We identified multiple major gaps in knowledge of the extent to which these criteria are met, including a lack of quantitative data on breeding productivity under current commercial breeding practices, the scale and scope of commercial breeding practices in growing parrot markets, particularly in the Middle East and Asia, and the lack of financial viability of captive breeding under effective regulation to prevent laundering or use of wild-sourced specimens as breeding stock. The capacity for captive breeding to displace demand for wild-sourced parrots varied between species, and complex interactions between trade in different species and contexts sometimes made consequences of commercial production difficult to predict. Decision makers and regulatory authorities should approach commercial captive breeding of parrots with caution and take into account knowledge gaps and cross-linkages between trade in different species to avoid unanticipated consequences from stimulating and facilitating unsustainable trade in wild-sourced parrots.

Una revisión de la cría comercial de loros en cautiverio como una intervención en la oferta para abordar el comercio no sustentable Resumen El volumen y la escala de la cría comercial de loros en cautiverio ha crecido de gran manera en las últimas décadas. Aunque se ha propuesto, y a menudo se asume, que la cría en cautiverio puede reducir la presión sobre las poblaciones silvestres, apenas se ha analizado la escala, viabilidad o impacto de este método para evitar la sobreexplotación de los loros, en comparación con enfoques similares en otros taxones amenazados, como pangolines o tigres. Revisamos la bibliografía primaria y gris para evaluar cuantitativa y cualitativamente las pruebas relativas a cinco criterios, establecidos a priori, para la cría comercial de loros en cautiverio como una intervención eficaz del lado de la oferta. Usamos una muestra de 16 especies amenazadas de loros que son objeto de intenso comercio o para las que el comercio no sustentable ha sido un factor en el declive de las poblaciones silvestre para representar una gama de grupos taxonómicos, historias de vida y regiones nativas. Identificamos múltiples vacíos importantes en el conocimiento de la medida en que se cumplen estos criterios, incluida la falta de datos cuantitativos sobre la productividad de la cría en las actuales prácticas de cría comercial, la escala y el alcance de las prácticas de cría comercial en los mercados de loros en crecimiento, especialmente en Medio Oriente y Asia, y la falta de viabilidad financiera de la cría en cautiverio bajo una regulación eficaz para evitar el lavado o el uso de especímenes de origen silvestre como plantel reproductor. La capacidad de la cría en cautiverio para desplazar la demanda de loros de origen silvestre varió según las especies y las complejas interacciones entre el comercio de diferentes especies y contextos dificultaron a veces la predicción de las consecuencias de la producción comercial. Los responsables de la toma de decisiones y las autoridades reguladoras deben abordar la cría comercial de loros en cautiverio con cautela y tener en cuenta los vacíos de conocimiento y los nexos cruzados entre el comercio de diferentes especies para evitar consecuencias imprevistas derivadas de estimular y facilitar el comercio no sustentable de loros de origen silvestre.

Archaeogenomic evidence from the southwestern US points to a pre-Hispanic scarlet macaw breeding colony.

Hundreds of scarlet macaw (Ara macao cyanoptera) skeletons have been recovered from archaeological contexts in the southwestern United States and northwestern Mexico (SW/NW). The location of these skeletons, >1,000 km outside their Neotropical endemic range, has suggested a far-reaching pre-Hispanic acquisition network. Clear evidence for scarlet macaw breeding within this network is only known from the settlement of Paquimé in NW dating between 1250 and 1450 CE. Although some scholars have speculated on the probable existence of earlier breeding centers in the SW/NW region, there has been no supporting evidence. In this study, we performed an ancient DNA analysis of scarlet macaws recovered from archaeological sites in Chaco Canyon and the contemporaneous Mimbres area of New Mexico. All samples were directly radiocarbon dated between 900 and 1200 CE. We reconstructed complete or near-complete mitochondrial genome sequences of 14 scarlet macaws from five different sites. We observed remarkably low genetic diversity in this sample, consistent with breeding of a small founder population translocated outside their natural range. Phylogeographic comparisons of our ancient DNA mitogenomes with mitochondrial sequences from macaws collected during the last 200 years from their endemic Neotropical range identified genetic affinity between the ancient macaws and a single rare haplogroup (Haplo6) observed only among wild macaws in Mexico and northern Guatemala. Our results suggest that people at an undiscovered pre-Hispanic settlement dating between 900 and 1200 CE managed a macaw breeding colony outside their endemic range and distributed these symbolically important birds through the SW.

Two independent approaches to assessing the constancy of evaporative water loss for birds under varying evaporative conditions.

We examine here the effects on evaporative water loss, at and below thermoneutrality, of perturbing the evaporative environment for the red-capped parrot (Purpureicephalus spurius) by modifying the ambient relative humidity or the diffusive properties of the ambient environment using a helium­oxygen mix (helox). We found that evaporative water loss did not change with relative humidity at an ambient temperature of 30 °C, but there was a negative relationship for evaporative water loss with relative humidity at 20 and 25 °C. The evaporative water loss per water vapour pressure deficit between the bird and its ambient environment was not constant with relative humidity, as would be expected for a physical effect (slope = 0); rather there was a significant positive relationship with relative humidity at ambient temperatures of 25 and 30 °C. Consequently, we conclude that the red-capped parrot can physiologically control its EWL over a range of relative humidities. For the first time for a bird species, we also confirmed EWL control using a second methodology to perturb the evaporative environment, and demonstrated that a more diffusive helox atmosphere has no effect on evaporative water loss of live birds, but evaporative water loss was higher for dead birds in helox compared to air. Our results for evaporative water loss and other physiological variables for red-capped parrots are consistent with the hypothesis that evaporative water loss is under physiological control.

Minimum anesthetic concentration of isoflurane and sparing effect of midazolam in Quaker parrots (Myiopsitta monachus).

OBJECTIVE: To determine the effects of midazolam on the minimum anesthetic concentration (MAC) reduction of end-tidal isoflurane concentration (Fe'Iso) measured using an electrical stimulus in Quaker parrots (Myiopsitta monachus). STUDY DESIGN: Randomized crossover experimental study. ANIMALS: A group of six adult Quaker parrots, weighing 98-124 g. METHODS: Birds were anesthetized with isoflurane in oxygen delivered by mask, then tracheally intubated and mechanically ventilated. Three treatments were applied with a 4 day interval between anesthetic events. Each anesthetized bird was administered midazolam (1 mg kg-1; treatment MID1), midazolam (2 mg kg-1; treatment MID2) or electrolyte solution (control) intramuscularly. The treatments were administered using a replicated Latin square design and the observers were blinded. Based on a pilot bird, the starting Fe'Iso was 1.8%. After equilibration for 10 minutes, a supramaximal stimulus was delivered using an electrical current (20 V and 50 Hz for 10 ms) and birds were observed for non-reflex movement. The Fe'Iso was titrated by 0.1% until a crossover event was observed. The MAC was estimated using logistic regression. RESULTS: The MAC of isoflurane (MACISO) was estimated at 2.52% [95% confidence interval (CI), 2.19-2.85] with a range of 1.85-2.65%. MACISO in MID1 was 2.04% (95% CI, 1.71-2.37) and in MID2 was 1.81% (95% CI, 1.48-2.14); reductions in MACISO from control of 19% (p = 0.001) and 28% (p < 0.001), respectively. Heart rate, temperature, sex and anesthetic time were not different among treatments. CONCLUSIONS: Midazolam (1-2 mg kg-1) intramuscularly resulted in a significant isoflurane-sparing effect in response to a noxious stimulus in Quaker parrots without observable adverse effects. CLINICAL RELEVANCE: Midazolam can be used as part of a balanced anesthetic approach using isoflurane in Quaker parrots, and potentially in other psittacine species.

Prevalence and characterisation of wounds in sheep attributed to attacks by kea (Nestor notabilis) on high country farms in New Zealand.

Aims: To characterise and classify wounds in sheep suspected to have been caused by attacks by kea (Nestor notabilis) (kea strike), and to report the prevalence of these wounds on five high country farms in the South Island of New Zealand.Methods: Data were collected from farms between 28 August 2012 and 20 September 2013. Sheep were examined opportunistically immediately after shearing for signs of wounds caused by kea. The age and sex of sheep were also recorded. Wounds were measured and characterised as recent, healing, or healed, and the estimated true prevalence was calculated for each farm.Results: Injuries consistent with kea strike wounds were identified in 70/13,978 (0.5%) sheep examined. The estimated true prevalence varied between farms, from 0 (95% CI = 0-0.16) to 1.25 (95% CI = 0.97-1.61)%. Of the 76 wounds identified, 61 (80%) were located in the lumbar region, and 74 (97%) consisted of full-thickness ulceration of the skin, one showed evidence of injury to muscle and one to bone. The median length of the 63 wounds measured was 6 (min 1, max 23.5) cm, and 10/63 (13%) were categorised as recently healed, 47/63 (62%) as healing, and 17/63 (22%) as recent wounds.Conclusions: The results of this study show that kea strike on sheep was occurring at a low prevalence on the high country farms surveyed. The wounds identified were survivable, but the welfare impact of kea strike on sheep should be considered in balance with the conservation status of kea. There was clear variation in the prevalence of wounds attributed to kea strike between the farms but we were not able to identify the risk factors contributing to these differences. Future studies of kea strike should examine variables such as altitude, local kea density and distribution, and differences in kea strike management and husbandry practices, and should include high country farms without a history of kea strike.

Sperm morphology and evidence for sperm competition among parrots.

Sperm competition is an important component of post-copulatory sexual selection that has shaped the evolution of sperm morphology. Previous studies have reported that sperm competition has a concurrently directional and stabilizing effect on sperm size. For example, bird species that show higher levels of extrapair paternity and larger testes (proxies for the intensity of sperm competition) have longer sperm and lower coefficients of variation in sperm length, both within and between males. For this reason, these sperm traits have been proposed as indexes to estimate the level of sperm competition in species for which other measures are not available. The relationship between sperm competition and sperm morphology has been explored mostly for bird species that breed in temperate zones, with the main focus on passerine birds. We measured sperm morphology in 62 parrot species that breed mainly in the tropics and related variation in sperm length to life-history traits potentially indicative of the level of sperm competition. We showed that sperm length negatively correlated with the within-male coefficient of variation in sperm length and positively with testes mass. We also showed that sperm is longer in sexually dichromatic and in gregarious species. Our results support the general validity of the hypothesis that sperm competition drives variation in sperm morphology. Our analyses suggest that post-copulatory sexual selection is also important in tropical species, with more intense sperm competition among sexually dichromatic species and among species that breed at higher densities.

How canaries listen to their song: Species-specific shape of auditory perception.

The melodic, rolling songs of canaries have entertained humans for centuries and have been studied for decades by researchers interested in vocal learning, but relatively little is known about how the birds listen to their songs. Here, it is investigated how discriminable the general acoustic features of conspecific songs are to canaries, and their discrimination abilities are compared with a small parrot species, the budgerigar. Past experiments have shown that female canaries are more sexually responsive to a particular song element-the "special" syllables-and consistent with those observations, it was found that special syllables are perceptually distinctive for canaries. It is also shown that canaries discriminate the subtle differences among syllables and phrases using spectral, envelope, and temporal fine structure cues. Yet, while canaries can hear these fine details of the acoustic structure of their song, the evidence overall suggests that they listen at a more global, phrase by phrase level, rather than an analytic, syllable by syllable level, except when attending to some features of special syllables. These results depict the species-specific shape of auditory perception in canaries and lay the groundwork for future studies examining how song perception changes seasonally and according to hormonal state.

The Use of Alfaxalone in Quaker Parrots (Myiopsitta monachus).

Alfaxalone is a neurosteroid anesthetic that acts on gamma-aminobutyric acid alpha-receptors. The objective of this study was to evaluate the clinical safety and efficacy of alfaxalone (Alfaxan CD). Due to observed hyperexcitability in the subject animals when alfaxalone was the only drug used during the initial trials, premedication with midazolam was also evaluated during the final study. Ten adult Quaker parrots (Myiopsitta monachus) were assigned to 3 groups: 1) low-dose alfaxalone 10 mg/kg (LD), 2) high-dose alfaxalone 25 mg/kg (HD), and 3) alfaxalone 10 mg/ kg with midazolam 1 mg/kg premedication (AM), administered intramuscularly. Induction time, sedation quality, duration of action, and vital parameters, including heart rate, respiratory rate, and temperature, were recorded. All protocols achieved adequate sedation; however, muscle tremors and hyperexcitation were variable. The LD group had a significantly longer mean ± SD induction time (13.5 ± 4.5 minutes) as compared to the HD (6.0 ± 1.3 minutes, P = .002) and AM (6.5 ± 2.9 minutes, P = .006) groups, while recovery time was significantly longer in the HD group (86.2 ± 13.4 minutes) than the LD group (44.4 ± 10.8 minutes, P < .001). Midazolam premedication resulted in reduction of both muscle tremors and hyperexcitation associated with alfaxalone administration, but the recovery time was significantly longer (103.5 ± 15.1 minutes, P < .001) than for the LD group. Alfaxalone as a sole agent resulted in muscle tremors and hyperexcitation during induction, which was attenuated by premedication with midazolam. Further investigation is warranted to characterize the effects of alfaxalone and drugs used to premedicate Quaker parrots.

Avian thermoregulation in the heat: evaporative cooling capacity and thermal tolerance in two Australian parrots.

Avian orders differ in their thermoregulatory capabilities and tolerance of high environmental temperatures. Evaporative heat loss, and the primary avenue whereby it occurs, differs amongst taxa. Although Australian parrots (Psittaciformes) have been impacted by mass mortality events associated with extreme weather events (heat waves), their thermoregulatory physiology has not been well characterized. We quantified the upper limits to thermoregulation under extremely hot conditions in two Australian parrots: the mulga parrot (Psephotellus varius; ∼55 g) and the galah (Eolophus roseicapilla; ∼265 g). At air temperatures (Ta) exceeding body temperature (Tb), both species showed increases in Tb to maximum values around 43-44°C, accompanied by rapid increases in resting metabolic rate above clearly defined upper critical limits of thermoneutrality and increases in evaporative water loss to levels equivalent to 700-1000% of baseline rates at thermoneutral Ta Maximum cooling capacity, quantified as the fraction of metabolic heat production dissipated evaporatively, ranged from 1.71 to 1.79, consistent with the known range for parrots, similar to the corresponding range in passerines, and well below the corresponding ranges for columbids and caprimulgids. Heat tolerance limit (the maximum Ta tolerated) ranged from 44 to 55°C, similar to the range reported for passerines, but lower than that reported for columbids and caprimulgids. Our data suggest that heat tolerance in parrots is similar to that in passerines. We argue that understanding how thermoregulatory capacity and heat tolerance vary across avian orders is vital for predicting how climate change and the associated increase in frequency of extreme weather events may impact avian populations in the future.

Urofecal steroid profiles of captive Blue-fronted parrots (Amazona aestiva) with different reproductive outcomes.

Despite Psitaciformes (parrots) being the third largest nonpasserine order (398 species), it currently ranks second in number of threatened species (28%) according to the Internatinal Union for Conservation of Nature (IUCN) criteria. Since most of the literature concerning reproductive endocrinology in avian species derives from domestic and song birds, it is puzzling that advances in reproductive science for the Psitaciformes order lags far behind, in spite of the growing threats against them. In order to expand our knowledge of Neotropical parrots (Psittacidae), we examined annual changes in urofecal sex steroid metabolites of Blue-fronted amazon pairs (Amazona aestiva) exhibiting successful (nestlings) and unsuccessful breeding (infertile or no eggs). Urofecal samples were collected over a year from eight breeding pairs housed under the same environmental and management conditions. Fecal androgen and progestagen concentrations were determined in males and females, respectively, by enzyme immunoassays previously validated for this species. All eggs were registered between late winter and mid-spring, and egg-laying intervals varied between females (range: 1-8 days; average 3.60 ±â€¯0.51 days). Similar profiles of urofecal progestagens were observed in reproductively successful females and females producing infertile eggs, with progestagen peaks preceding egg laying events (1.77 ±â€¯0.50 days). In contrast, non-laying females had no rises in progestagens during the year. Successful and unsuccessful males did not displayed distinct annual patterns of androgen production, and apart from the peaks during the breeding season, more than half of the individuals intriguingly presented significant increases from late summer to early autumn, a period without reproductive activity. Finally, we noticed that samples with progestagen levels exceeding 40 ng/g had very high probability (>97.5%) to be from females in pre-laying or laying phases, suggesting a feasible application of this characteristic to noninvasively discriminate the reproductive status in amazon females with an accuracy and sensitivity of 94.55% and 58.13%, respectively. Our findings confirmed that urofecal progestagens and androgens are good indicators of the gonadal condition in Blue-fronted amazons, but there is still much to be done for their extensive use in artificial insemination or selection of the most suitable breeding birds for the season.

Seven Years of Parrot Conservation in La Moskitia, Honduras.

The population of the Central American scarlet macaw ( Ara macao cyanoptera) and other parrots have and continue to decline throughout the region largely from poaching to supply the illegal wildlife trade. Conservation efforts address this issue through protection efforts, including community patrols and government engagement, as well as nest monitoring, rescue and release operations, capacity building, and education and consciousness raising programs, all of which rely on long-lasting relationships and commitment. Using these principles, in 2010, a coalition of people came together, including the authors, to build a conservation program against overwhelming odds and with surprising success.

Skeletogenesis of Myiopsitta monachus (Psittaciformes) and sequence heterochronies in Aves.

The ossification sequence of Myiopsitta monachus was determined. Myiopsitta has a similar sequence to other altricial birds, with delayed skeletons compared to precocial species. The hindlimbs ossify before the forelimbs, a condition that could be linked to altriciality. To determine the stability of the sequences of ossification across birds, we selected species of different groups of Aves and used event-pairing method and character mapping on a phylogeny. Our results show that the homogeneity in the development of birds was supported by 56.77% of the character states. Event-pair cracking phylogenetic method was applied to identify sequence heterochronies. Results reveal a high number of heterochronies and show that the long bones in limbs may behave as modules. In Myiopsitta, the ossa ectethmoidale and mesethmoidale ossify early. These bones provide the origin site of the Psittaciformes' novel adductor m. ethmomandibularis, associated with strong bite forces, and its acceleration in the sequence may correspond to the functional hypothesis. Also, the early appearance of some hyoid apparatus elements occurs, and could be related to the development of tongue in Psittaciformes and its role in handling food, and is in concordance with the functional and size hypothesis.

Are parrots poor at motor self-regulation or is the cylinder task poor at measuring it?

The ability to inhibit unproductive motor responses triggered by salient stimuli is a fundamental inhibitory skill. Such motor self-regulation is thought to underlie more complex cognitive mechanisms, like self-control. Recently, a large-scale study, comparing 36 species, found that absolute brain size best predicted competence in motor inhibition, with great apes as the best performers. This was challenged when three Corvus species (corvids) were found to parallel great apes despite having much smaller absolute brain sizes. However, new analyses suggest that it is the number of pallial neurons, and not absolute brain size per se, that correlates with levels of motor inhibition. Both studies used the cylinder task, a detour-reaching test where food is presented behind a transparent barrier. We tested four species from the order Psittaciformes (parrots) on this task. Like corvids, many parrots have relatively large brains, high numbers of pallial neurons, and solve challenging cognitive tasks. Nonetheless, parrots performed markedly worse than the Corvus species in the cylinder task and exhibited strong learning effects in performance and response times. Our results suggest either that parrots are poor at controlling their motor impulses, and hence that pallial neuronal numbers do not always correlate with such skills, or that the widely used cylinder task may not be a good measure of motor inhibition.

Semen Collection and Spermatozoa Characteristics in the Kea Parrot (Nestor notabilis).

We describe the seminal characteristics of the kea parrot (Nestor notabilis), an endangered species endemic to the South Island of New Zealand. Semen was collected in the full breeding season from 6 birds in the collection of an amateur aviculturist. The manual massage technique was used. A total of 25 ejaculates was collected and evaluated for volume, degree of contamination, and spermatozoa concentration; motility and kinetic parameters were assessed on diluted samples (modified Tyrode's Albumin Lactate Pyruvate, pH 8.2, temperature 37.5°C) with a computer-aided sperm analyzer. Four ejaculates were not analyzed because of an excessively high degree of contamination. Semen color ranged from transparent or turbid yellow to whitish. The geometric mean of spermatozoa number/ejaculate was 765.9 ± 2084.7 × 106. Total and progressive motility were 71.7% ± 20.0% and 59.8% ± 22.0%, respectively. Great variability was observed both among birds and among different ejaculates of the same subject. The seminal characteristics of kea are worth further investigation, with the aim of relating semen quality to fertility and defining a minimum inseminating dose for breeding purposes. A deeper knowledge of male reproductive biology also can increase the success of breeding programs and enable the use of the kea as a model species for other more threatened species, such as the kaka ( Nestor meridionalis ) and the kakapo (Strigops habroptila).

Can you teach an old parrot new tricks? Cognitive development in wild kaka (Nestor meridionalis).

Despite recent efforts to characterize innovative individuals within a species, we still know very little about the ontogeny of innovation ability. A number of studies have found that innovation rates are correlated with personality traits, such as neophilia and exploration. Juvenile birds are frequently more neophilic and explorative, yet few studies have found evidence of age-related differences in innovative problem-solving success. Here, we show consistently higher innovation efficiency in juveniles of a wild, omnivorous parrot species across a variety of tasks and contexts. We tested 104 kaka (Nestor meridionalis), ranging in age from four months to 13 years. Twenty-four individuals participated in all three of our problem-solving tasks, two of which involved a familiar feeder and one an entirely novel apparatus. Juveniles were the most efficient problem-solvers in all three tasks. By contrast, the adults' success was context dependent and limited to the novel apparatus, which did not require modification of a pre-learned behavioural response. This suggests greater behavioural flexibility in the juvenile birds, who also showed higher persistence and exploratory diversity than adults. These traits may enable young kaka to discover efficient foraging techniques, which are then maintained throughout adulthood.

Opposing selection and environmental variation modify optimal timing of breeding.

Studies of evolution in wild populations often find that the heritable phenotypic traits of individuals producing the most offspring do not increase proportionally in the population. This paradox may arise when phenotypic traits influence both fecundity and viability and when there is a tradeoff between these fitness components, leading to opposing selection. Such tradeoffs are the foundation of life history theory, but they are rarely investigated in selection studies. Timing of breeding is a classic example of a heritable trait under directional selection that does not result in an evolutionary response. Using a 22-y study of a tropical parrot, we show that opposing viability and fecundity selection on the timing of breeding is common and affects optimal breeding date, defined by maximization of fitness. After accounting for sampling error, the directions of viability (positive) and fecundity (negative) selection were consistent, but the magnitude of selection fluctuated among years. Environmental conditions (rainfall and breeding density) primarily and breeding experience secondarily modified selection, shifting optimal timing among individuals and years. In contrast to other studies, viability selection was as strong as fecundity selection, late-born juveniles had greater survival than early-born juveniles, and breeding later in the year increased fitness under opposing selection. Our findings provide support for life history tradeoffs influencing selection on phenotypic traits, highlight the need to unify selection and life history theory, and illustrate the importance of monitoring survival as well as reproduction for understanding phenological responses to climate change.

Does vocal learning accelerate acoustic diversification? Evolution of contact calls in Neotropical parrots.

Learning has been traditionally thought to accelerate the evolutionary change of behavioural traits. We evaluated the evolutionary rate of learned vocalizations and the interplay of morphology and ecology in the evolution of these signals. We examined contact calls of 51 species of Neotropical parrots from the tribe Arini. Parrots are ideal subjects due to their wide range of body sizes and habitats, and their open-ended vocal learning that allows them to modify their calls throughout life. We estimated the evolutionary rate of acoustic parameters of parrot contact calls and compared them to those of morphological traits and habitat. We also evaluated the effect of body mass, bill length, vegetation density and species interactions on acoustic parameters of contact calls while controlling for phylogeny. Evolutionary rates of acoustic parameters did not differ from those of our predictor variables except for spectral entropy, which had a significantly slower rate of evolution. We found support for correlated evolution of call duration, and fundamental and peak frequencies with body mass, and of fundamental frequency with bill length. The degree of sympatry between species did not have a significant effect on acoustic parameters. Our results suggest that parrot contact calls, which are learned acoustic signals, show evolutionary rates similar to those of morphological traits. This is the first study to our knowledge to provide evidence that change through cultural evolution does not necessarily accelerate the evolutionary rate of traits acquired through life-long vocal learning.

Exploiting the richest patch has a fitness pay-off for the migratory swift parrot.

1. Unlike philopatric migrants, the ecology of nomadic migrants is less well understood. This life-history strategy reflects responses to spatiotemporal variation in resource availability and the need to find resource rich patches to initiate breeding. The fitness consequences of movements between regions of patchily distributed resources can provide insight into ecology of all migrants and their responses to global change. 2. We link broad-scale data on spatiotemporal fluctuation in food availability to data on settlement patterns and fitness outcomes for a nomadic migrant, the endangered swift parrot Lathamus discolor. We test several predictions to determine whether facultative movements are adaptive for individual swift parrots in an environment where resources are patchily distributed over time and space. 3. Variation in the availability of swift parrot food resources across our study period was dramatic. As a consequence, swift parrots moved to breed wherever food was most abundant and did not resettle nesting regions in successive years when food availability declined. By moving, swift parrots exploited a variable food resource and reproduced successfully. 4. Exploiting the richest patches allowed swift parrots to maintain stable fitness outcomes between discrete breeding events at different locations. Unlike sedentary species that often produce few or lower quality offspring when food is scarce, nomadic migration buffered swift parrots against extreme environmental variation. 5. We provide the first detailed evidence that facultative movements and nomadic migration are adaptive for individuals in unpredictable environments. Our data support the widely held assumption that nomadic migration allows animals to escape resource limitation.

A novel form of spontaneous tool use displayed by several captive greater vasa parrots (Coracopsis vasa).

Parrots are frequently cited for their sophisticated problem-solving abilities, but cases of habitual tool use among psittacines are scarce. We report the first evidence, to our knowledge, of tool use by greater vasa parrots (Coracopsis vasa). Several members of a captive population spontaneously adopted a novel tool-using technique by using pebbles and date pits either (i) to scrape on the inner surface of seashells, subsequently licking the resulting calcium powder from the tool, or (ii) as a wedge to break off smaller pieces of the shell for ingestion. Tool use occurred most frequently just prior to the breeding season, during which time numerous instances of tool transfer were also documented. These observations provide new insights into the tool-using capabilities of parrots and highlight the greater vasa parrot as a species of interest for studies of physical cognition.