A single Haemoproteus plataleae haplotype is widespread in white ibis (Eudocimus albus) from urban and rural sites in southern Florida.

The American white ibis (Eudocimus albus), a common bird species in Florida, has become increasingly urban, with many populations relying heavily on urban and suburban habitats, which may alter parasite transmission. Parasites of ibis, especially haemosporidians, are understudied. Avian haemosporidia can have a wide range of impacts on birds, including decreased reproductive success or increased mortality. Because southern Florida is subtropical and has a high diversity of potential vectors for haemosporidia, we hypothesized that there will be a high prevalence and genetic diversity of haemosporidia in white ibis. A total of 636 ibis from South Florida were sampled from 2010 to 2022, and blood samples were tested for haemosporidia by examination of Giemsa-stained thin blood smears and/or nested PCRs targeting the cytochrome b gene. A total of 400 (62.9%, 95% CI 59-66.7%) ibis were positive for parasites that were morphologically identified as Haemoproteus plataleae. Sequences of 302 positives revealed a single haplotype of Haemoproteus (EUDRUB01), which was previously reported from white ibis in South Florida and captive scarlet ibis (E. ruber) in Brazil. No Plasmodium or Leucocytozoon infections were detected. Parasitemias of the 400 positive birds were very low (average 0.084%, range 0.001%-2.16% [although only 2 birds had parasitemias >1%]). Prevalence and parasitemias were similar for males and females (68% vs. 61.6% and 0.081% vs. 0.071%, respectively). Prevalence in juveniles was lower compared with adults (52% vs. 67.4%) but parasitemias were higher in juveniles (0.117% vs. 0.065%). This data shows that H. plataleae is common in ibis in South Florida. Although parasitemias were generally low, additional research is needed to determine if this parasite has subclinical effects on ibis, if additional haplotypes or parasite species infect ibis in other regions of their range, or if H. plataleae is pathogenic for other sympatric avian species.

Comparative morphology and soft tissue histology of the remote-touch bill-tip organ in three ibis species of differing foraging ecology.

Ibises (order: Pelecaniformes, family: Threskiornithidae) are probe-foraging birds that use 'remote-touch' to locate prey items hidden in opaque substrates. This sensory capability allows them to locate their prey using high-frequency vibrations in the substrate in the absence of other sensory cues. Remote-touch is facilitated by a specialised bill-tip organ, comprising high densities of mechanoreceptors (Herbst corpuscles) embedded in numerous foramina in the beak bones. Each foramen and its associated Herbst corpuscles make up a sensory unit, called a 'sensory pit'. These sensory pits are densely clustered in the distal portion of the beak. Previous research has indicated that interspecific differences in the extent of sensory pitting in the beak bones correlate with aquatic habitat use of ibises, and have been suggested to reflect different levels of remote-touch sensitivity. Our study investigates the interspecific differences in the bone and soft tissue histology of the bill-tip organs of three species of southern African ibises from different habitats (mainly terrestrial to mainly aquatic). We analysed the external pitting pattern on the bones, as well as internal structure of the beak using micro-CT scans and soft tissue histological sections of each species' bill-tip organs. The beaks of all three species contain remote-touch bill-tip organs and are described here in detail. Clear interspecific differences are evident between the species' bill-tip organs, both in terms of bone morphology and soft tissue histology. Glossy Ibises, which forage exclusively in wetter substrates, have a greater extent of pitting but lower numbers of Herbst corpuscles in each pit, while species foraging in drier substrates (Hadeda and Sacred Ibises) have more robust beaks, fewer pits and higher densities of Herbst corpuscles. Our data, together with previously published histological descriptions of the bill-tip organs of other remote-touch foraging bird species, indicate that species foraging in drier habitats have more sensitive bill-tip organs (based on their anatomy). The vibrations produced by prey (e.g., burrowing invertebrates) travel poorly in dry substrates compared with wetter ones (i.e., dry soil vs. mud or water), and thus we hypothesise that a more sensitive bill-tip organ may be required to successfully locate prey in dry substrates. Furthermore, our results indicate that the differences in bill-tip organ anatomy between the species reflect complex trade-offs between morphological constraints of beak shape and remote-touch sensitivity requirements, both of which are likely related to each species' foraging behaviour and substrate usage. Our study suggests that structures in the bone of the bill-tip organ could provide valuable osteological correlates for the associated soft tissues, and consequently may provide information on the sensory ecology and habitat usage of the birds in the absence of soft tissues.

INVESTIGATION INTO CARDIOVASCULAR ASSESSMENT OF CAPTIVE ADULT SCARLET IBIS (EUDOCIMUS RUBER).

Cardiovascular lesions are commonly diagnosed postmortem in scarlet ibis (Eudocimus ruber), but antemortem diagnosis is rare. The aim of this study was to evaluate the cardiovascular health of a zoo population (n = 44) of apparently healthy, adult, scarlet ibis. A cross-sectional study design was employed whereby each animal was manually restrained for physical examination, phlebotomy, and echocardiographic examination performed with a 12-MHz transducer and a ventromedial approach, and observed intervals were calculated for 12 parameters. Seven individuals from the study population had high left-sided mid-ventricular velocities (2.59-5.89 m/sec) compared with values in other species. Follow-up examination suggested that these mid-ventricular obstructive lesions were dynamic and transient in nature rather than caused by fixed lesions within the outflow tract and may therefore be associated with stress. Conscious echocardiography proved to be feasible, although, unsurprisingly, the stress response in nonhabituated birds appeared to increase blood flow velocities. Handling protocols likely have a significant effect on echocardiographic parameters and should be taken into consideration when interpreting findings. Serum cholesterol concentrations were generally high (7.4-13.0 mmol/L), and further work is required to investigate the relationship between circulating cholesterol and the development of atherosclerosis in scarlet ibis. Serum cardiac troponin I concentrations were measured, and four animals were identified with suspected elevated levels, likely indicative of myocardial damage.

The complete mitochondrial genome of an Asian crested ibis Nipponia nippon (Pelecaniformes, Threskiornithidae) from South Korea.

The complete mitochondrial genome sequence from the Asian crested ibis, Nipponia nippon (Aves, Pelecaniformes, Threskiornithidae), was determined and characterized in detail. This mitochondrial genome is 16,813 bp long, and consists of 13 PCGs, 22 tRNAs, and 2 rRNAs. The nucleotide composition is slightly biased with A + T contents of 53.79% (A, T, C, and G was 30.37%, 23.42%, 31.99%, and 14.22%, respectively). 11 PCGs are initiated by ATN codons, except for cox1 and cox2 with GTG instead. The phylogenetic relationships based on the maximum-likelihood and Bayesian methods showed that the placement of N. nippon within the order Pelecaniformes, with forming the monoclade of the family Threskiornithidae.

Investigating individual and social behaviour of the Northern bald ibis (Geronticus eremita): behavioural variety and welfare.

The Northern bald ibis (Geronticus eremita) (NBI) is one of the most threatened birds in the world. Intense conservation efforts have been undertaken and several research projects on the species are being done in Morocco and in Europe. Observing animal behaviour has been proved to be an efficient and non-invasive technique to assess the animal welfare, with the performance of a wide array of natural behaviours being one of the mostly used indicators of good mental and physical well-being. The aim of this study was to investigate the behaviour of a flock of 14 zoo-living NBI of different ages. The study focused on the variety of species-specific individual and social behaviours, in the light of reintroduction of the study juveniles in the wild. Per subject, 20 10-min. sessions were done. A continuous focal animal sampling method was used to collect individual and social behaviours. Behavioural data have been compared between adults and juveniles. Moreover, a Behavioural Variety Index (BVI) has been proposed and calculated based on previous literature describing natural ibis behaviours. The BVI might help in the evaluation of the variety of behaviours performed by each individual and the monitoring of the diversity of the behavioural repertoire of zoo animals. Our results showed that the birds performed species-specific behaviours and no abnormal behaviour was reported. Moreover, the BVI highlighted a good behavioural variety as each bird performed approximately 78% of the natural behaviours described in the Northern bald ibis and in close relative species. Our findings seem to suggest the presence of qualitative and quantitative similarities between the behavioural repertoires of the study ibises and those described in wild conspecifics, suggesting a good welfare of the colony. Finally, the BVI proposed in the current study seems to be a useful and practical tool to test behavioural diversity in zoo animals.

The complete mitochondrial genome sequence of Eudocimus ruber (Pelecaniformes:Threskiornithidae).

The Eudocimus ruber (Scarlet ibis) belongs to the bird order Pelecaniformes. Here, we sequenced the mitochondrial genome of E. ruber. The complete mitochondrial genome of E. ruber is 16 697 bp in length and contains 22 tRNA genes, 2 rRNA genes, 13 protein-coding genes and a non-coding control region. Consistent with other sequenced birds, most genes are encoded on the heavy strand, except for ND6 and 8 tRNA genes. The overall base composition of the E. ruber is 30.8% A, 30.8% C, 13.8%G and 24.6% T. The molecular-based phylogenetic tree suggested that E. ruber has close affinities with birds from family Threskiornithidae as expected.