Developing artificial nest boxes for a large aquatic mammal

Abstract

1. Nest boxes and other human-made constructions have been widely and successfully used as conservation tools to increase nest-availability for hollowdependent fauna, especially birds and some small and medium mammals.2. This study applies, for the first time, this recovery technique to a large aquatic mammal, aiming to improve resting, birthing and nursing sites of endangered Saimaa ringed seals (Pusa hispida saimensis) by developing artificial nest boxes. This landlocked subspecies' breeding habitat is severely affected by climate change. Because of mild winters, sufficient ice and snow habitat for subnivean lairs is lacking.3. In this study, floating nest boxes were developed. It was found that free-ranging ringed seals accept nest boxes as sites for resting, birthing and nursing. Thirtyfour boxes in total were offered during six successive breeding seasons. Almost half (47%) of the available boxes were used by seals, and two pups were born and reared in the boxes during the 6-year study. 4. Our study indicates that this innovative technique can be a valuable tool for the Saimaa ringed seal conservation in the changing climate.

The risks and rewards of using artificial habitat structures for wildlife conservation

“…Increasingly, conservationists and developers seek to supplement these destroyed habitat components with artificial habitat structures—i.e., purposefully designed human‐made substitutes for critical features of natural habitats that animals use to bask (Moore, 2019), reproduce (Knaepkens et al, 2004), hibernate (Latham & Knowles, 2008), and take refuge from predators (Bourke et al, 2017) and environmental stressors (Griffiths et al, 2018). They are now used globally in marine, freshwater, and terrestrial environments for a diversity of taxa, including invertebrates (Green, 2005), reptiles (Souter et al, 2004), terrestrial and aquatic mammals (Harley, 2006; Kunnasranta et al, 2022), birds (Hart et al, 2016), amphibians (Latham & Knowles, 2008), and fish (Simpson et al, 2020).…”

“…Live stems were not predicted to contain either hollows before ~40 years post‐fire, while the probability of hollows in dead stems increased following fire, and peaked at ~50–60 yearsManaging fire to maintain habitat resources for hollow‐dependent mallee fauna requires long intervals with no fireExperimentalMurray Mallee, south east Australia1‐5‐2023Knaepkens et al (2004) https://link.springer.com/article/10.1023/B:BIOC.0000048448.17230.40To evaluate the use of ceramic tiles as artificial spawning substrates (tiles) in canalised and (remaining) meandering parts of anthropogenically perturbed lowland rivers for the endangered European bullhead ( Cottus gobio )Tiles were successfully used by the bullhead as spawning substrates. In the meandering parts of the river, the number of egg deposits was significantly positively correlated with water depth, while in canalised river parts, water depth and velocity were of no importance for tile usageThe authors suggest that the supplementation of rivers with artificial substrates like tiles may be a promising, inexpensive and easy‐to‐use enhancement technique for degraded bullhead spawning habitatExperimentalLowland rivers in Flanders, Belgium2‐5‐2023Kunnasranta et al (2022) https://doi.org/10.1002/aqc.3851Determine the efficacy of artificial floating nest boxes for improving resting, birthing and nursing sites of the endangered Saimaa ringed seals ( Pusa hispida saimensis )Free‐ranging ringed seals accept nest boxes as sites for resting, birthing and nursing. Thirty‐four boxes in total were offered during six successive breeding seasons.…”

Genomic evidence uncovers inbreeding and supports translocations in rescuing the genetic diversity of a landlocked seal population

“…Reducing the losses caused by climate change and other human-induced effects is vital for reaching favorable population size and strengthening the genetic diversity of the Saimaa ringed seal population. In addition to translocations, several actions are being carried out to improve seal survival into adulthood: fishing restrictions, water-level regulation, land use planning, building artificial nest boxes, and improving snow conditions by piling snow, are key conservation elements (see e.g., Kunnasranta et al 2021Kunnasranta et al , 2022.…”