Burrow Occupancy Research Articles

Simulation Modeling to Assess Line Transect Distance Sampling Under a Range of Translocation Scenarios

Abstract The accuracy of posttranslocation population monitoring methods is critical to assessing long-term success in translocation programs. Translocation can produce unique challenges to monitoring efforts; therefore, it is important to understand the flexibility and robustness of commonly used monitoring methods. In Florida, USA, thousands of gopher tortoises Gopherus polyphemus have been, and continue to be, translocated from development sites to permitted recipient sites. These recipient sites create a broad range of potential monitoring scenarios due to variability in soft-release strategies, habitat conditions, and population demographics. Line transect distance sampling is an effective method for monitoring natural tortoise populations, but it is currently untested for translocated populations. We therefore produced 3,024 individual-based, spatially explicit scenarios of translocated tortoise populations that differed in recipient site and tortoise population properties, based on real-world examples, literature review, and expert opinion. We virtually sampled simulated tortoise populations by using line transect distance sampling methods and built a Bayesian hierarchical model to estimate the population density for each simulation, which incorporated individual-level covariates (i.e., burrow width and burrow occupancy). Line transect distance sampling was largely appropriate for the conditions that typify gopher tortoise recipient sites, particularly when detection probability on the transect lines was greater than or equal to 0.85. Designing the layout of transects relative to the orientation of soft-release pens, to avoid possible sampling biases that lead to extreme outliers in estimates of tortoise densities, resulted in more accurate population estimates. We also suggest that use of individual-level covariates, applied using a Bayesian framework as demonstrated in our study, may improve the applicability of line transect distance sampling surveys in a variety of contexts and that simulation can be a powerful tool for assessing survey design in complex sampling situations.

Environmental and individual determinants of burrow-site microhabitat selection, occupancy, and fidelity in eastern chipmunks living in a pulsed-resource ecosystem.

Habitat selection has major consequences on individual fitness, particularly selection for breeding sites such as nests or burrows. Theory predicts that animals will first use optimal habitats or rearrange their distribution by moving to higher-quality habitats whenever possible, for instance when another resident disperses or dies, or when environmental changes occur. External constraints, such as predation risk or resource abundance, and interindividual differences in age, sex and body condition can lead to variation in animals' perception of habitat quality. Following habitat use by individuals over their lifetime is thus essential to understand the causes of variation in habitat selection within a population. We used burrow occupancy data collected over eight years to assess burrow-site selection in a population of wild eastern chipmunks (Tamias striatus) relying on pulsed resources. We first compared characteristics of burrow microhabitats with those of equivalent unused plots. We then investigated the factors influencing the frequency of burrow occupation over time, and the individual and environmental causes of annual burrow fidelity decisions. Our results indicate that chipmunks select microhabitats with a greater number of woody debris and greater slopes. Microhabitats of burrows with higher occupancy rates had a lower shrub stratum, were less horizontally opened and their occupants' sex-ratio was skewed towards males. Burrow fidelity was higher in non-mast years and positively related to the occupant's age, microhabitat canopy cover and density of large red maples. The quality of a burrow microhabitat appears to be determined in part by characteristics that favour predation avoidance, but consideration of occupancy and fidelity patterns over several years also highlighted the importance of including individual and contextual factors in habitat selection studies.

Resilience to a severe marine heatwave at two Pacific seabird colonies

A severe marine heat wave (MHW) persisted in the California Current ecosystem from 2014 through 2016. The MHW featured record-high sea surface temperatures in 2015, with 2014 to 2016 being the warmest 3 yr period on record. Our decade-long (2010-2019) breeding and diet monitoring of the rhinoceros auklet Cerorhinca monocerata, a burrow-nesting seabird, at significant breeding colonies on Destruction Island (California Current) and Protection Island (Salish Sea) allowed us to compare reproductive and dietary responses to this MHW. Although the colonies are relatively close to each other, and their reproductive output is, on average, similar, the auklets’ responses to the MHW differed. At Destruction Island, burrow occupancy rates were lower during the MHW (0.54 ± 0.02 vs. 0.61 ± 0.02 [mean ± SE] in non-MHW years), suggesting that birds skipped breeding, but fledging success rates did not differ (0.85 ± 0.02 vs. 0.89 ± 0.03). At Protection Island, burrow occupancy remained at non-MHW levels (0.72 ± 0.02 vs. 0.69 ± 0.02), but reproductive success declined (0.71 ± 0.03 vs. 0.82 ± 0.02). Chick provisioning also showed different patterns. The energy (kJ) per bill load at Destruction Island showed no clear MHW effect, while at Protection Island, it was reduced. At the same time, bill-load prey item count rose at Protection Island, indicating increased foraging effort and/or a reduction in diet quality. Our results further suggest rhinoceros auklets may be more resilient than other seabird species to major climate perturbations. However, with MHWs predicted to become more frequent and severe, the auklets’ ability to maintain these levels of breeding success will be tested.

Soil moisture associations with burrow occupancy and reproductive success of Leach’s Storm-Petrels

Soil moisture associations with burrow occupancy and reproductive success of Leach’s Storm-Petrels

Asistiendo a la reintroducción de vizcachas (Lagostomus maximus): ¿Cómo aumentar el área de pastoreo seguro?

The reintroduction of fossorial mammals could be limited by the availability of satellite burrows that provide refuge from predators while foraging away from their permanent burrows, and by availability of short grasses. In order to generate information to assist in the reintroduction of vizcachas (Lagostomus maximus), we asked: 1) what type of satellite burrow do they accept based on burrow complexity, entrance size and distance from permanent burrows?, and 2) how did the provision of burrows and mowing affect their foraging range? We carried out the study in the Sierras of Cordoba, Argentina, with 13 vizcachas transferred to two adaptation pens equipped with permanent burrows. We mowed part of the vegetation around the pens and we dug 14 satellite burrows of two types: simple with only a tunnel, and complex with a tunnel and underground chamber. Burrows were situated between 1 and 16 m from the pens. For six months we evaluated satellite burrow occupancy. We also counted feces, estimated bare soil, and height of the vegetation in 15-m-long transects originating in the entrances of highly used burrows, which were distributed in two sectors. Occupancy was 2 and 67% for simple and complex satellite burrows, respectively, and was negatively related to burrow entrance size. There was no relationship between burrow occupancy and distance to adaptation pens. Transect sampling showed that 91% of the pellets were within 4 m of the pens or satellite burrows, and that they preferred cut to uncut grass. We conclude that building complex satellite burrows and mowing vegetation will increase secure foraging range for translocated vizcachas.

Monogamy in the Burrowing Shrimp Axianassa australis Rodrigues & Shimizu, 1992 (Decapoda, Gebiidea, Axianassidae).

Our knowledge of the mating systems in burrowing shrimps (infraorders Axiidea and Gebiidea) is still rather limited. Here we describe the burrow use pattern, sex ratio, and sexual dimorphism of the burrowing shrimp Axianassa australis to test for monogamy, considering that monogamous species live in heterosexual pairs and exhibit a low degree of sexual dimorphism. To this end, a total of 226 individuals of A. australis were collected from the northeast region of Brazil. Our results showed that A. australis inhabited its burrows mainly as pairs, most of which were male-female pairs. In agreement with the expectations, specimens of A. australis were found dwelling as heterosexual pairs more frequently than expected by chance alone. The presence of ovigerous females was associated with the burrow occupation; that is, brooding females were more frequently observed in male-female combinations than solitarily. Also supporting theoretical considerations, we did not observe sexual dimorphism in body size between males and females of the population and the different categories of the burrow occupation. Conversely, sexual dimorphism in cheliped size was evident in the population, with larger chelipeds in males than in females. This observation agrees with that reported for most burrowing shrimps in which male-male competition is the main evolutionary force of sexual selection. The observations above favor the hypothesis that A. australis is primarily monogamous, with a small fraction of the males moderately promiscuous.

Factors affecting burrow occupancy and bank persistence for Bank Swallows breeding in aggregate (sand and gravel) pits and natural habitats

Factors affecting burrow occupancy and bank persistence for Bank Swallows breeding in aggregate (sand and gravel) pits and natural habitats

Trialling camera traps to determine occupancy and breeding in burrowing seabirds

AbstractBurrowing seabirds are important in ecological and conservation terms. Many populations are in flux due to both negative and positive anthropogenic impacts, but their ecology makes measuring changes difficult. Reliably recording key metrics, the proportion of burrows with breeding pairs and the success of breeding attempts requires burrow‐level information on occupancy. We investigated the use of camera traps positioned at burrow entrances for determining the number of breeding pairs in a sample to inform population estimates, and for recording breeding success. The performance of two cameras makes we tested differed markedly, with Spypoint Force 10 trail cameras prone to malfunction while Reconyx HC600 Hyperfire cameras performed well. Nevertheless, both makes yielded season‐long activity patterns for individual burrows, eliminating uncertainty around successful fledging attempts. Dimensionality reduction of activity metrics derived from camera time series suggests breeding and non‐breeding burrows may be identifiable using linear discriminant analyses but sample sizes from our trial were low and group means were only significantly different during certain breeding stages (permutational multivariate analysis of variance: early chick‐rearing f = 3.64, P = 0.06; late chick‐rearing f = 8.28, P = 0.009). Compared with traditional techniques for determining burrow occupancy (e.g. manual burrow inspection and playback of conspecific calls at burrow entrances), camera traps can reduce uncertainty in estimated breeding success and potentially breeding status of burrows. Significant up‐front investment is required in terms of equipment and human resources but for long‐term studies, camera traps may deliver advantages, particularly when unanticipated novel observations and the potential for calibrating traditional methods with cameras are factored in.

Estimated Abundance of Hydrobates leucorhous (Leach's Storm-Petrel) on Hay Island, New Brunswick

Hydrobates leucorhous (Leach's Storm-Petrel) is widely distributed throughout the Northern Hemisphere, but its North American populations are declining. The causes and extent of the decline are uncertain, making continued population monitoring and identification of colonies a priority for the management of this species. Detailed long-term studies of a large colony on Kent Island in the Grand Manan Archipelago, NB, Canada, have been ongoing since the 1930s, yet the presence and abundance of petrels nesting on neighboring islands is poorly documented. We conducted a census of Hay Island, which is connected to Kent Island by a 300-m stretch of intertidal zone, during mid-incubation in July of 2018 to determine burrow densities and occupancy rates and estimate the breeding population size. We estimated the population of breeding pairs to be 2786 (95% CI ± 624), with most active burrows and the highest burrow occupancy rates occurring in open, non-forested areas dominated by Dryopteris spp. (wood ferns). Overall burrow densities and occupancy rates on Hay Island were lower than nearby colonies. Baseline population estimates of Leach's Storm-Petrels in unassessed colonies like Hay Island are important for on-going monitoring, improving regional population estimates, and conservation planning.

Assessing multiple threats to seabird populations using flesh-footed shearwaters Ardenna carneipes on Lord Howe Island, Australia as case study

Globally, seabird populations have been in decline due to multiple threats throughout their range. Separating simultaneous pressures is challenging and can require significant amounts of data over long periods of time. We use spatial contrasts to investigate the relative importance of several drivers for the purported decline in a species listed as in decline as an example species, the Flesh-footed shearwater (Ardenna carneipes). On Lord Howe Island in the Tasman Sea, Australia, this seabird suffers from habitat loss due to housing development, intensive mortality in fisheries, plastic ingestion, and roadkill due to vehicular traffic on its breeding island. We repeated a quantitative survey of the population to ascertain whether the decline previously reported had continued and to evaluate the purported mortality sources (Reid et al. in PLoS ONE 8(4):e58230, 2013, Lavers et al. in Global Ecol Conserv 17:e00579, 2019). We measured burrow density, area of occurrence, occupancy and breeding success, integrating them with previous surveys using a Bayesian statistical model to generate longer term estimates of demographic rates. We used spatial patterns to test whether mortality on roads or proximity to human habitation was influencing population demographics. In contrast to predictions, we found the population had stabilised or increased. Characteristics such as burrow occupancy and breeding success showed little pattern, with weak evidence for impacts from road mortality and housing development. Such a data-rich approach is substantially more informative and can better support seabird conservation and management efforts does require more field-time and additional equipment than most contemporary surveys, the data is substantially more informative and can better clarify the results of efforts in seabird conservation and management.

Combining survey and remotely sensed environmental data to estimate the habitat associations, abundance and distribution of breeding thin-billed prions Pachyptila belcheri and Wilson\u2019s storm-petrels Oceanites oceanicus on a South Atlantic tussac island

Small petrels are the most abundant seabirds in the Southern Ocean. However, because they breed in burrows on remote and often densely vegetated islands, their colony sizes and conservation status remain poorly known. To estimate the abundance of these species on Bird Island in the Falkland archipelago, we systematically surveyed their breeding burrow density and occupancy across this near-pristine tussac (Poa flabellata)-covered island. By modelling burrow density as functions of topography and Sentinel 2 satellite-derived Normalised Difference Vegetation Index data, we inferred habitat associations and predicted burrow abundance of the commonest species—Thin-billed Prions (Pachyptila belcheri) and Wilson’s Storm-petrels (Oceanites oceanicus). We estimate that there are 631,000 Thin-billed Prion burrows on the island (95% CI 496,000–904,000 burrows). Assuming that burrow occupancy lies between 12 and 97%, this equates to around 76,000–612,000 breeding pairs, making Bird Island the second or third largest P. belcheri colony in the world, holding approximately 3–27% of the species’ breeding population. We estimate that 8200–9800 (95% CI 5,200–18,300 pairs) pairs of Wilson’s Storm-petrels also breed on the island. Notably, the latter burrowed predominantly under and within tussac pedestals, whereas they are usually assumed to breed in rock cavities. Thin-billed Prions are declining in the Kerguelen archipelago, but their population trends in the Falklands are unknown. Given the wide confidence intervals around our own and other population estimates for these cryptic species, we recommend that their populations should be monitored regularly, at multiple sites.

Nesting ecology and reuse of nest burrows by Bank Swallow (<i>Riparia riparia</i>) in southern Yukon

Bank Swallow (<i>Riparia riparia</i>) is a declining insectivorous bird that nests colonially in near-vertical surfaces, including natural banks along waterways as well as those created by industrial excavation. Several threats are likely contributing to the population decline, conservation measures have been recommended, and monitoring methods have been developed. However, little is known of this species in the extensive boreal portion of its breeding range. To assess whether recommendations developed in southern areas are likely to be effective in a more northerly region, we investigated aspects of the nesting ecology of Bank Swallow in southern Yukon during 2013–2017. Nesting activity occurred between 20 May and 21 August. We found an exceptional abundance of nest burrows in natural riverbanks along 46 km of the Yukon River near Whitehorse (326 burrows/km), but relatively low percent burrow occupancy in both natural and artificial habitats compared to studies from other regions. Year-to-year persistence of nest burrows and rates of reuse of burrows were high compared to other studies. We highlight the potential importance of the boreal region for recovery of Bank Swallow in Canada, and the importance of using region-specific estimates of percent occupancy when monitoring Bank Swallow using burrow counts. Further study is needed to determine whether unoccupied burrows contribute to nesting success, and whether there are situations in which Bank Swallow burrows should be protected year-round instead of only during nesting.

Burrow emergence rhythms of Nephrops norvegicus by UWTV and surveying biases

Underwater Television (UWTV) surveys provide fishery-independent stock size estimations of the Norway lobster (Nephrops norvegicus), based directly on burrow counting using the survey assumption of “one animal = one burrow”. However, stock size may be uncertain depending on true rates of burrow occupation. For the first time, 3055 video transects carried out in several Functional Units (FUs) around Ireland were used to investigate this uncertainty. This paper deals with the discrimination of burrow emergence and door-keeping diel behaviour in Nephrops norvegicus, which is one of the most commercially important fisheries in Europe. Comparisons of burrow densities with densities of visible animals engaged in door-keeping (i.e. animals waiting at the tunnel entrance) behaviour and animals in full emergence, were analysed at time windows of expected maximum population emergence. Timing of maximum emergence was determined using wave-form analysis and GAM modelling. The results showed an average level of 1 visible Nephrops individual per 10 burrow systems, depending on sampling time and depth. This calls into question the current burrow occupancy assumption which may not hold true in all FUs. This is discussed in relation to limitations of sampling methodologies and new autonomous robotic technological solutions for monitoring.

Burrow occupation rates and spatial distribution within habitat of the ghost crab Ocypode quadrata (Fabricius, 1787): Implications for impact assessments

The most conspicuous characteristic of ghost crabs (Crustacea: Ocypodidae) is the construction of semi-permanent burrows on the sand, widely used as tools for impact assessments. Thus, it is now critical to understand the factors driving burrowing activity and burrow occupation rates, including the effects of natural and anthropogenic disturbances. We tested three hypotheses in the present study with the ghost crab Ocypode quadrata: (i) overestimation of population size by traditional burrow counts depends on disturbance level at local scale; (ii) burrow occupation rate is density-dependent; and (iii) the predominant spatial distribution of burrows within the habitat is uniform. The last two predictions were assessed using a meta-analysis for a macro scale assessment. The comparison of distinct methods for burrow counting confirmed that ghost crab density is overestimated on non-urbanized beaches at local scale. A non-linear relationship between burrow occupation rates and burrow density was found at local and regional scales. When burrow density increases, the burrow occupation rate is also higher. However, from approximately 20 to 30 burrows/100 m2, the occupation rate reduces with increased density. Thus, the overestimation of the ghost crab density on non-urbanized beaches can be partially explained by a density-dependence in burrowing activity probably driven by a stronger intraspecific competition on non-urbanized areas. Finally, the distribution pattern of the ghost crab is predominantly uniform in most of its distribution range, despite of urbanization level and sampling design, hence suggesting intra-specific interactions as a driver of burrowing behaviour. In conclusion, burrow density, occupation rate and spatial distribution within the habitat evidenced at various spatial scales that burrowing activity of the ghost crab is density-dependent and this constitutes an issue never considered before in impact assessments inherent to coastal monitoring and management.

Alien mammal assemblage effects on burrow occupancy and hatching success of the vulnerable pink-footed shearwater in Chile

SummaryAlien species are a driver of biodiversity loss, with impacts of different aliens on native species varying considerably. Identifying the contributions of alien species to native species declines could help target management efforts. Globally, seabirds breeding on islands have proven to be highly susceptible to alien species. The breeding colonies of the pink-footed shearwater (Ardenna creatopus) are threatened by the negative impacts of alien mammals. We combined breeding monitoring data with a hierarchical model to separate the effects of different alien mammal assemblages on the burrow occupancy and hatching success of the pink-footed shearwater in the Juan Fernández Archipelago, Chile. We show that alien mammals affected the rates of burrow occupancy, but had little effect on hatching success. Rabbits produced the highest negative impacts on burrow occupancy, whereas the effects of other alien mammals were more uncertain. In addition, we found differences in burrow occupancy between islands regardless of their alien mammal assemblages. Managing rabbits will improve the reproductive performance of this shearwater, but research is needed to clarify the mechanisms by which alien mammals affect the shearwaters and to explain why burrow occupancy varies between islands.

A survey of Great-winged Petrels Pterodroma macroptera breeding at sub-Antarctic Marion Island and a revised global population estimate

Although burrow-nesting petrels are the most abundant group of seabirds in the Southern Ocean, their global populations are poorly known, because most species breed on remote islands. For example, there are no accurate estimates for Great-winged Petrel Pterodroma macroptera populations at any of its major breeding sites. Moreover, current global population estimates for Great-winged Petrels of approximately 1.5 million birds include counts of the closely related Grey-faced Petrel P. gouldi, which is now recognised as a different species. On sub-Antarctic Marion Island, Great-winged Petrel burrows found within random strip transects were counted and then burrow densities were extrapolated by GIS-derived habitat attributes to generate an island-wide burrow estimate (33 000 burrows). Burrow occupancy rates at the start of incubation averaged 48 ± 29% (range 10–94%) during one-off surveys at ten sites around the island, and repeat surveys found at least 42% of burrows were occupied by breeders. This suggests there were approximately 14 000 occupied burrows (95% CI 9 500–18 500) on Marion Island in 2015. Collating data from other breeding sites suggests that the global breeding population is perhaps 100 000–150 000 pairs (400 000–600 000 birds).

Breeding abundance and population trend of the Peruvian Diving-petrel Pelecanoides garnotii in Chile: Recovery of an endangered seabird?

SummaryAs island ecosystems are among the most critical breeding habitats for seabirds, their protection should enhance population viability for many species. The Peruvian Diving-petrel Pelecanoides garnotii breeds only in Chile and Perú, is an endangered seabird with historically large populations of over 100,000 breeding pairs, but fewer than 1,000 remained in the 1980s and it became the first endangered seabird of the Humboldt Current System. In Chile, they breed on five islands, three of which are legally protected, but only two have a management plan. Between 2010 and 2014, we evaluated the density of nests, burrow occupancy, and colony patch sizes on the islands to estimate the breeding population. The population trend was assessed by compiling historical data available in the literature and several unpublished technical reports. The current breeding population size in Chile was ∼12,500 breeding pairs (95% CI: 10,613–14,676 pairs) that is ∼34% of the breeding pairs reported for Peru (∼36,450 pairs). Choros Island, the only island with adequate protection, accounted for ∼95% of the total breeding population of the Peruvian Diving-petrel in Chile. Historical population trends showed a significant increase in breeding pairs during recent years on Choros Island. It seems that the adequate legal protection of Choros Island is leading to the recovery of Peruvian Diving-petrels, demonstrating that protection of breeding colonies remains an essential strategy for the conservation of endemic seabirds.

Prey remains of brown skua is evidence of the long-term decline in burrow occupancy of blue petrels and thin-billed prions at Mayes Island, Kerguelen

Skuas are top predator and scavenger seabirds in marine and terrestrial ecosystems and monitoring their diet can provide valuable insights on the abundance and distribution of prey. The diet of the brown skua was studied at Mayes Island, Kerguelen archipelago, by collection of prey remains during their breeding cycle in 2013. We investigated a potential diet shift by comparing our results to those obtained two decades ago at the same colony. Our results confirmed the high specialisation of this skua colony in active predation of two burrowing petrels: the blue petrel and the thin-billed prion. We observed a shift in the diet of the brown skua with the importance of the thin-billed prion dropping significantly by 15%. Concomitantly, we observed a decreasing trend of burrow occupancy of the two main preys, with a more severe decline for the thin-billed prion. We suspected a dietary shift of brown skuas at Mayes Island related to a change in the relative abundance of blue petrels and thin-billed prions. Diet of brown skuas appears to be a valuable indicator of the relative abundance of burrowing petrels when they constitute the main food resource during breeding.

Interspecific and intraspecific interactions between fiddler crabs Minuca pugnax (mud fiddler) and Leptuca pugilator (sand fiddler) influence species' burrowing behavior

Species occupying similar habitat and functional niches will necessarily have some external force driving differentiation between them, thus creating complementarity, or otherwise face high competition for resources. In order to fully understand the role of each species in an ecosystem and their contributions to ecosystem function, it is important to understand the nature of these interactions. However, for species that occur in the same spatial niche and appear to occupy redundant functional niches, it is often difficult to distinguish between complementarity and redundancy and therefore to designate the functional role each species plays. We used two co-occurring fiddler crab species that are presumed to be functionally similar, Leptuca pugilator (sand fiddler crab) and Minuca pugnax (mud fiddler crab), to explore how species interactions may influence burrowing behavior. We ran manipulative mesocosm experiments to assess potential effects of species interactions on the number and location of burrows as well as the burrowing behavior of the crabs. Overall, sand fiddler crabs dug more burrows on average than mud fiddlers across all experiments while mud fiddlers were choosier about the location and sediment type of their burrows, suggesting complementarity in burrowing between the two species. Burrow counts in heterospecific treatments suggest that neither species interfered with nor enhanced burrow creation by the other species. However, increased burrow occupancy by mud fiddlers in the presence of sand fiddlers and aggressive behavior by mud fiddlers toward sand fiddlers suggest that mud fiddler crabs may receive refuge benefits from sand fiddler crabs through antagonistic rather than facilitative interactions. Thus, species-specific habitat use and interspecific interactions are likely influencing the role each species plays as a burrower and marsh ecosystem engineer.

Spatial and seasonal variation in occupation and abundance of common vole burrows in highly disturbed agricultural ecosystems

Understanding how species respond to disturbance in human-modified ecosytems is critical for management and conservation of biodiversity in the Anthropocene. In agroecosystems, human disturbances severely modify the habitat of species, particularly for those that live in burrows. The common vole Microtus arvalis (Pallas, 1778) is a semi-fossorial microtine, which often exhibits large abundance fluctuations, becoming an agricultural pest in peak years. We evaluated how both agrarian disturbances (via types of crop and their management) and landscape heterogeneity influenced the abundance of common vole burrow systems along a yearly cycle, at the field and landscape scales. We seasonally recorded the number of burrows and their recent occupation in circular plots of 200-m radius including different types of crops in intensified agrarian landscapes in NW Spain. Our results showed a marked seasonal and spatial pattern in both total abundance and abundance of occupied burrows. After a population peak year, only 31% of burrows were occupied across the year (from 41% in spring–summer to 12% in autumn). The crop type and its management in relation to soil disturbance were the main factors driving seasonal and spatial dynamics of burrow abundance at the field and landscape scale. Alfalfa fields held the highest abundance of both total and occupied burrow systems across the year, while fields of traditional-tilled cereal retained the lowest. As a result, at the landscape scale, plots with a greater surface devoted to traditional cereal crops maintained a lower relative number of burrow systems. Regarding the landscape structural heterogeneity, plots with longer length of field margins and lower area of watercourses maintained higher abundance of burrow systems. An adequate landscape-scale planning of crop types, agricultural practices, and distribution of non-crop habitats could be a promising sustainable method to reduce the risk of crop-damaging vole plagues.