Wire-mesh nest exclosures installed around Hudson's canastero Asthenes hudsoni nests were associated with 57% cumulative survival compared with 4.5% for nests without exclosures. Adults rapidly resumed nest attendance, no abandonment was attributed to installation, and camera traps recorded at least 16 predation attempts blocked by the exclosures.
Foxes prey upon clutches of ground-nesting birds, and in Australia this constitutes a conservation problem for which no effective solution currently exists. We trialled the application of dog urine spray around camera-monitored, mock plover nests in a wetland (eight with urine, eight with a water control) in an attempt to reduce loss to predators and increase clutch survival. No survival benefit was detectable. We also studied predator visits to treated and control nests; no difference occurred in the number of putative predators at urine-treated nests, including foxes. This small trial suggests there would be little benefit to further study, or application of, dog urine to protect nests in our study system.
The hard-ground swamp deer Rucervus duvaucelii branderi, once widespread in Central India, is now restricted to a single population in Kanha Tiger Reserve. To reduce extinction risk and expand the subspecies’ range, the Madhya Pradesh Forest Department translocated 98 individuals from Kanha to Satpura Tiger Reserve between 2015 and 2023. Deer were moved in seven phases and released across three sites: a predator-proof enclosure in the Bori range, and open grasslands in Bori and Churna (Malini). We evaluated the effectiveness of this conservation translocation through nine years of monitoring data on population size, age–sex structure, and body condition. By 2023, the population had grown to 172 individuals. Body condition scores showed that deer in Satpura were comparable to the source population in Kanha. Mortality remained low, with most deaths attributed to predation or natural causes. These results show that the reintroduction, supported by habitat restoration, veterinary care, and regular monitoring, has established a stable and growing population. This case study illustrates the value of long-term planning, adaptive management, voluntary village relocation, and targeted habitat investment in recovering threatened herbivores. It offers a practical and replicable model for future reintroduction efforts in managed landscapes across India and beyond.
A dramatic decline in American eel Anguilla rostrata abundance led to the species being assessed as Endangered in Ontario (Canada) and the closure of fisheries. As part of efforts to recover populations, four million eels (glass eels and elvers) were batch marked and released over a five-year period (2006-2010) into the upper St. Lawrence River and Lake Ontario. Over 2019-2022, we repeated an earlier large-scale electrofishing survey of eastern Lake Ontario tributaries done to assess the distribution and survival of the released eels. A decade later, we collected two hundred and fifteen eels from 19 sites along four rivers near the release site. Eels were absent from three tributaries occupied in 2010-2011. Along the Trent River, navigational locks have likely permitted migration past seven large dams previously assessed as probably impassable. Growth of translocated eels was variable among rivers. As well, many eels were still smaller than yellow eels naturally migrating into Lake Ontario. Our study indicates high, long-term post-release survival in these rivers. However, timing of out-migration and potential for successful spawning migrations remain unknown.
Corn bunting Emberiza calandra is a UK red-listed species that requires significant conservation effort within agricultural landscapes to maintain populations. Its preference for nesting in cereal fields and other crops puts it at considerable risk from farming operations. In North East Scotland, where most cereals are spring-sown and nesting attempts in May and June are often in the taller denser swards of grass silage fields, nest destruction during mowing is a major problem. Delayed mowing increases nest survival rates, but also lowers the quality of forage so has limited uptake in agri-environment schemes. Potentially a more attractive solution to farmers are ‘green manure’ crops, which involve growing plants with nitrogen-fixing and other properties to improve soil condition in arable fields. These crops are becoming increasingly popular amongst farmers, but in North East Scotland are usually sown during spring. To test whether autumn-sown green manure would provide an attractive, safe nesting habitat for corn buntings in May and June the following year, we conducted a trial across six farms in 2021–2023. Results confirmed that sowing in September enabled the crop swards to become sufficiently tall and dense to attract nesting corn buntings the following spring. Furthermore, average nest survival rates in the trial plots (60%) were similar to those in cereal fields later in the season (70%), and much higher than grass fields (25%). We conclude that autumn-sown green manure crops can provide a safe alternative to grass silage fields during late spring to early summer, when corn buntings have few other nesting habitats available.
