Artificial refuges for wildlife conservation: what is the state of the science?

Abstract

Artificial refuges are human-made structures that aim to create safe places for animals to breed, hibernate, or take shelter in lieu of natural refuges. Artificial refuges are used across the globe to mitigate the impacts of a variety of threats on wildlife, such as habitat loss and degradation. However, there is little understanding of the science underpinning artificial refuges, and what comprises best practice for artificial refuge design and implementation for wildlife conservation. We address this gap by undertaking a systematic review of the current state of artificial refuge research for the conservation of wildlife. We identified 224 studies of artificial refuges being implemented in the field to conserve wildlife species. The current literature on artificial refuges is dominated by studies of arboreal species, primarily birds and bats. Threatening processes addressed by artificial refuges were biological resource use (26%), invasive or problematic species (20%), and agriculture (15%), yet few studies examined artificial refuges specifically for threatened (Vulnerable, Endangered, or Critically Endangered) species (7%). Studies often reported the characteristics of artificial refuges (i.e. refuge size, construction materials; 87%) and surrounding vegetation (35%), but fewer studies measured the thermal properties of artificial refuges (18%), predator activity (17%), or food availability (3%). Almost all studies measured occupancy of the artificial refuges by target species (98%), and over half measured breeding activity (54%), whereas fewer included more detailed measures of fitness, such as breeding productivity (34%) or animal body condition (4%). Evaluating the benefits and impacts of artificial refuges requires sound experimental design, but only 39% of studies compared artificial refuges to experimental controls, and only 10% of studies used a before-after-control-impact (BACI) design. As a consequence, few studies of artificial refuges can determine their overall effect on individuals or populations. We outline a series of key steps in the design, implementation, and monitoring of artificial refuges that are required to avoid perverse outcomes and maximise the chances of achieving conservation objectives. This review highlights a clear need for increased rigour in studies of artificial refuges if they are to play an important role in wildlife conservation.

Domestication Explains Two-Thirds of Differential-Gene-Expression Variance between Domestic and Wild Animals; The Remaining One-Third Reflects Intraspecific and Interspecific Variation

“…The practical value of Belyaev's concept has been realized in a huge collection of commercial fur colors-e.g., "Amber-gold pastel," "Ashen," "Beige," "Black crystal," "Cobalt," "Ermine-like," "Peach," ""Pearl," Platinum," "Purple," "Silver sable-like," "Steel-blue," and "Straw,"-rarely or never seen in the wild [6]. The concept's fundamental importance has found confirmation in a large variety of breeds of dogs [7], cats [8], pigs [9], cows [10], horses [11], sheep [12], goats [13], chickens [14], ducks [15], geese [16], and other domestic animals [17] as well as in artificial shelters and additional feeding for wild animals in wildlife for saving them [18]. On the basis of Belyaev's concept [1], a laboratory model of animal domestication by humans has been created using outbred lines of tame and aggressive rats artificially bred [19] for performance on a standard glove test [20].…”

Response to Brack and Sparks

“…Perhaps our paper evoked such a passionate response because conservation biologists have long considered bat boxes a critical intervention where natural roost habitat is lacking. However, we firmly assert that the complex microclimates in bat boxes (and other artificial refuges) are understudied (see also Cowan et al, 2021) and that the cavalier use of unsuitable boxes could expose bats to deadly temperatures. Further, we reaffirm that through careful study and by communicating findings to managers, we can resolve uncertainties and make bat boxes safer for bats.…”

Artificial nesting hollows for the conservation of Carnaby’s cockatoo Calyptorhynchus latirostris: definitely not a case of erect and forget

“…The impacts of this destruction and degradation on biota that rely on tree hollows/cavities for breeding or roosting have been recognised for decades (Lack 1954;Saunders et al 1982;Newton 1994). In addressing this loss of breeding and roosting habitat, there has been a long history of providing artificial installations such as nest boxes and hollows for many species on those continents (Newton 1994;Gibbons and Lindenmayer 2002;Vaughan et al 2003;Cowan et al 2021). Despite the large number of papers on nest/roost site augmentation, there has been a marked lack of rigour in the approach to installing and assessing the efficacy of artificial refuges.…”

“…Despite the large number of papers on nest/roost site augmentation, there has been a marked lack of rigour in the approach to installing and assessing the efficacy of artificial refuges. It is fair to state that in the majority of cases, installations were ad hoc, guided by the belief that 'if you build them they will be used' (Saunders et al 2020;Cowan et al 2021). Saunders et al (2020) reviewed 40 nest site augmentation experiments, including those for parrots and cockatoos.…”

“…What was clear from the many studies of nest site augmentation was that the efficacy of artificial nesting sites is idiosyncratic and their conservation worth needs to be established for each species. Cowan et al (2021) reviewed 224 studies of artificial wildlife refuges implemented in the field for mainly for birds and bats, from 1948 to 2018. They found that with few exceptions, there is little understanding of the science underpinning artificial refuges and what comprises best practice for artificial refuge design and implementation for wildlife conservation.…”