Bald eagle mortality and nest failure due to clade 2.3.4.4 highly pathogenic H5N1 influenza a virus.

The bald eagle (Haliaeetus leucocephalus) is a culturally and ecologically vital species in North America that embodies conservation success but continues to face threats that include emerging pathogens. The introduction of A/goose/Guangdong/1/1996 lineage highly pathogenic (HP) clade 2.3.4.4b H5N1 influenza A virus (IAV) in North America in late 2021 resulted in high rates of mortality among bald eagles. Here we show an alarming rate of bald eagle nest failure and mortality attributed to HP IAV. We documented fatal, systemic HP IAV infection in breeding adult and nestling bald eagles along the southeastern U.S. coast. Concurrently, annual bald eagle nest surveys in Georgia and Florida revealed a precipitous drop in success in coastal counties compared with previous years, portending negative impacts on population recruitment. As an apex predator and efficient scavenger, it is likely that bald eagles become infected through consumption of infected waterfowl. These results and similar reports of raptor mortality in Europe, Asia, and Africa, indicate a clear threat to raptor health. The possible long-term persistence of HP H5N1 IAV in North America poses an impending threat to bald eagle populations not only related to direct mortality but also decreased recruitment and warrants continued efforts to understand these potential impacts.

Use of passive radio frequency identification technologies to monitor nest usage in the northern carmine bee-eater (Merops n. nubicus).

The use of radio frequency identification (RFID) technology is common in animal-monitoring applications in the wild and in zoological and agricultural settings. RFID is used to track animals and to collect information about movements and other behaviors, as well as to automate or improve husbandry. Disney's Animal Kingdom® uses passive RFID technology to monitor nest usage by a breeding colony of northern carmine bee-eaters. We implemented RFID technologies in various equipment configurations, initially deploying low-frequency (LF) 125 kHz RFID and later changing to high-frequency (HF) 13.56 MHz RFID technology, to monitor breeding behavior in the flock. We installed antennas connected to RFID readers at the entrances of nest tunnels to detect RFID transponders attached to leg bands as birds entered and exited tunnels. Both LF-RFID and HF-RFID systems allowed the characterization of nest visitation, including the timing of nest activity, breeding pair formation, identification of egg-laying females, participation by nonresidents, and detection of nest disruptions. However, we collected a substantially larger volume of data using the increased bandwidth and polling speed inherent with HF-RFID, which permitted tag capture of multiple birds simultaneously and resulted in fewer missed nest visits in comparison to LF-RFID. Herein, we describe the evolution of the RFID setups used to monitor nest usage for more than 7 years, the types of data that can be gained using RFID at nests, and how we used these data to gain insights into carmine bee-eater breeding behavior and improve husbandry.

Application of video recording technology to improve husbandry and reproduction in the carmine bee-eater (Merops n. nubicus).

Incorporating technology with research is becoming increasingly important to enhance animal welfare in zoological settings. Video technology is used in the management of avian populations to facilitate efficient information collection on aspects of avian reproduction that are impractical or impossible to obtain through direct observation. Disney's Animal Kingdom(®) maintains a successful breeding colony of Northern carmine bee-eaters. This African species is a cavity nester, making their nesting behavior difficult to study and manage in an ex situ setting. After initial research focused on developing a suitable nesting environment, our goal was to continue developing methods to improve reproductive success and increase likelihood of chicks fledging. We installed infrared bullet cameras in five nest boxes and connected them to a digital video recording system, with data recorded continuously through the breeding season. We then scored and summarized nesting behaviors. Using remote video methods of observation provided much insight into the behavior of the birds in the colony's nest boxes. We observed aggression between birds during the egg-laying period, and therefore immediately removed all of the eggs for artificial incubation which completely eliminated egg breakage. We also used observations of adult feeding behavior to refine chick hand-rearing diet and practices. Although many video recording configurations have been summarized and evaluated in various reviews, we found success with the digital video recorder and infrared cameras described here. Applying emerging technologies to cavity nesting avian species is a necessary addition to improving management in and sustainability of zoo avian populations.

Reproductive and parental behavior in Taveta golden weavers (Ploceus castaneiceps).

Taveta golden weavers are popular in zoos, but little has been published on their reproduction, social behavior, or other aspects of their management. At Disney's Animal Kingdom® , we have had great success with our breeding program and house a large flock in our mixed-species walk-through Africa aviary and smaller groups in the off-exhibit Avian Research Center. We conducted observations on both groups in order to document behavioral differences between the groups living under differing management conditions. Data on which individuals were inside, on or near focal nests were collected using a 30-s scan samples. Scan data were analyzed using a two-factor ANOVA, with aviary location and nest contents as the factors. We found that, in both aviary locations, females spent more time inside and on the nests than males did. As expected, females spent more time inside the nests containing eggs and more time on the nests containing chicks, likely due to incubation and chick-feeding demands, respectively. Interestingly, we found that females spent significantly more time inside their nests and males spent more time near their nests in the Africa aviary than in ARC. Despite Africa aviary's higher nest attendance, a higher proportion of nests fledged chicks in ARC (72% vs. 41%). These data are consistent with findings in wild sociable weavers [Spottiswoode, 2007. Oecologia 154: 589-600]. Future work with zoo-housed populations of weavers could help shed light on this phenomenon, which is not yet well understood. A better understanding of the consequences of different group sizes and housing conditions could have important implications for how Taveta weavers are managed.

Hand-rearing and sex determination tool for the Taveta golden weaver (Ploceus castaneiceps).

Improvements in the ability to hand-rear birds in captivity have aided zoological institutions in the sustainable management of these species, and have provided opportunities to examine their physical growth in varying conditions. Monitoring the weight gain and development of chicks is an important aspect of developing a hand-rearing protocol. In this paper we provide the institutional history for a colonial species of passerine, the Taveta golden weaver, at Disney's Animal Kingdom®, in order to demonstrate the methods of establishing a successful breeding program which largely incorporates hand-rearing in management of the population. We also tested if we could accurately predict sex of chicks using weights collected on Day 14 during the hand-rearing process. Using this tool, we were able to correctly determine sex before fledging in more than 83% of chicks. Early sex determination is important in captive species for genetic management and husbandry purposes. While genetic sexing can be expensive, we found that using growth curves to determine sex can be a reliable and cost-effective tool for population management of a colonial passerine.