Deep object detection for waterbird monitoring using aerial imagery Krish Kabrayz Alexander Xiongyz Wenbin Liyz Minxuan Luoz William Luz

2025-05-06 0 0 5.93MB 7 页 10玖币
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Deep object detection for waterbird monitoring
using aerial imagery
Krish Kabra,,, Alexander Xiong,, Wenbin Li,, Minxuan Luo, William Lu,
Tianjiao Yu, Jiahui Yu, Dhananjay Singh, Raul Garcia, Maojie Tang,
Hank Arnold§, Anna Vallery§, Richard Gibbons, Arko Barman§
Rice University, Houston, TX 77005, USA
§Houston Audubon Society, Houston, TX 77079, USA
American Bird Conservancy, The Plains, VA 20198, USA
Abstract—Monitoring of colonial waterbird nesting islands is
essential to tracking waterbird population trends, which are
used for evaluating ecosystem health and informing conservation
management decisions. Recently, unmanned aerial vehicles, or
drones, have emerged as a viable technology to precisely monitor
waterbird colonies. However, manually counting waterbirds from
hundreds, or potentially thousands, of aerial images is both
difficult and time-consuming. In this work, we present a deep
learning pipeline that can be used to precisely detect, count,
and monitor waterbirds using aerial imagery collected by a
commercial drone. By utilizing convolutional neural network-
based object detectors, we show that we can detect 16 classes of
waterbird species that are commonly found in colonial nesting
islands along the Texas coast. Our experiments using Faster
R-CNN and RetinaNet object detectors give mean interpolated
average precision scores of 67.9% and 63.1% respectively.
Index Terms—Object detection, Convolutional neural net-
works, Wildlife monitoring
I. INTRODUCTION
Colonial waterbird nesting islands can be found across
the globe, and each of North America’s coasts is home to
its own species of breeding colonial waterbirds. Colonial
waterbirds are important indicators of ecosystem health [1],
provide numerous ecosystem services, and are an important
part of a growing nature-based tourism sector of the economy
[2]. Therefore, continuing research and monitoring of these
species is critical to inform conservation decisions, encourage
management of habitats for the benefit of colonial waterbirds,
and to continue to gauge the surrounding ecosystem health.
Monitoring of waterbirds at colonial nesting islands is a
widespread technique used to track population trends. There
are many colonial waterbird monitoring programs in the U.S.
including the Texas Colonial Waterbird Survey, which is one of
the longest running programs that monitors waterbirds across
the entire Texas coast annually since 1976 [3]. Censusing
waterbirds on islands is no small task. Traditional monitoring
studies of waterbirds have been conducted by traversing the
colony on foot, surveying via boat, or surveying aerially using
small, manned aircraft. Each of these methods has its own
set of challenges and consequences. Surveying waterbirds by
foot can disturb both the species of interest and the habitat
Denotes equal contribution. Corresponding author: kk80@rice.edu
occupied. Low vantage points of boat-based surveys can result
in the risk of missing nests, particularly on larger and higher
islands. Moreover, in certain conditions, accessing the islands
by boat can be tricky due to inclement weather conditions.
Manned aerial surveys is the preferred technique by state and
federal wildlife agencies, but these are expensive and require
the proper conditions. In fact, aircraft crashes and boating
accidents have been found to be the largest causes of mortality
and injury among biologists in the field [4].
In recent years, unmanned aerial vehicles (UAVs), also
referred to as drones, have presented themselves as a useful
tool in wildlife management [5], [6], including waterbird
monitoring [7], [8]. Drones allow researchers to remain safely
on the ground while surveying areas of interest with both
less cost and greater ease than traditional aerial surveys. In
studies where this technology has been applied, the use of
drones was found to result in more precise count estimates
than traditional ground-based surveys [9]. Unfortunately, the
expertise and time required to manually localize and classify
species from hundreds, potentially thousands, of aerial images
represents a major bottleneck.
To alleviate this issue, we developed a object detection-
based deep learning pipeline that utilizes convolutional neural
networks (CNNs) [10]–[12] to precisely localize and classify
colonial waterbird species from UAV aerial imagery via super-
vised learning. We collect survey images from three colonial
nesting islands along the Texas coast, and train a CNN-based
object detection model to detect 16 classes of waterbirds, in-
cluding the 14 most common colonial waterbird species found
on these islands: Brown Pelican (Pelecanus occidentalis),
Laughing Gull (Leucophaeus atricilla), Royal Tern (Thalasseus
maximus), Sandwich Tern (Thalasseus sandvicensis), Great
Egret (Ardea alba), Cattle Egret (Bubulcus ibis), Snowy Egret
(Egretta thula), Reddish Egret (Egretta rufescens), American
White Ibis (Eudocimus albus), Great Blue Heron (Ardea
Herodias), Black-crowned Night Heron (Nycticorax nyctico-
rax), Tri-colored Heron (Egretta tricolor), Roseate Spoonbill
(Platalea ajaja), and Black Skimmer (Rynchops niger). We
present results using two of the most commonly implemented
CNN-based object detection models, Faster R-CNN [11] and
RetinaNet [12].
arXiv:2210.04868v2 [cs.CV] 13 Oct 2022
A. Contributions
The key contributions of this work are as follows:
We develop a deep learning pipeline to detect water-
birds from UAV aerial imagery for precise waterbird
monitoring. Our pipeline is general and can be applied
to other applications requiring object detection from
high-resolution aerial imagery, including other wildlife
monitoring applications. Our code is available at: https:
//github.com/RiceD2KLab/Audubon F21
We apply our method to detect 16 classes of waterbirds
from UAV aerial imagery collected from nesting islands
surveyed along the Texas coast. To the best of the authors’
knowledge, this is one of the largest number of species
detected by a single model for UAV-based waterbird
monitoring research.
We present experimental results utilizing Faster R-CNN
and RetinaNet object detectors. We show that we can
accurately detect 3 of the most prevalent waterbird classes
in our dataset (>70% of total waterbirds): Mixed Tern
Adults, Laughing Gull Adults, and Brown Pelican Adult,
with an interpolated average precision (APIoU=0.5) score
of over 90% for Faster R-CNN and 85% for RetinaNet.
Across all waterbird classes, we achieve a mean inter-
polated average precision (mAPIoU=0.5) scores of 67.9%
and 63.1% for Faster R-CNN and RetinaNet respectively.
II. RELATED WORK
In recent years, object detection, the task of localizing one
or more objects in an image with corresponding classifications,
has seen immense advancements largely due to the rapid
development of deep learning [13]. State-of-the-art object
detection architectures utilizing convolutional neural networks
(CNN) as a ‘backbone’ have particularly achieved much
success due to a CNN’s ability to learn hierarchical image
features [14], [15]. For this work we utilize two popular CNN-
based object detectors: Faster R-CNN [11] and RetinaNet [12].
Nevertheless, the proposed method is general, and is easily
extensible to other object detectors.
Consequent to the success of CNN-based object detection
and wide availability of open-source code, several works have
utilized these methods for wildlife monitoring with unmanned
aerial vehicle (UAV) imagery. Andrew et al. [16] use a R-
CNN [10] to detect Holstein Friesian cattle from UAV imagery,
proposing both a standard still-image acquisition pipeline and
an extended video monitoring pipeline. Kellenberger et al.
[17] use a custom one-stage detector with an AlexNet [14]
backbone to detect large animals from UAV images captured
over the Kuzikus wildlife reserve park in Namibia. Gray et al.
[18] use a Mask R-CNN [19] to detect and segment humpback
whales, minke whales, and blue whales from UAV imagery
collected off the coast of California and along the Western
Antarctic Peninsula.
More related to this work, researchers have also utilized
CNN-based object detectors for bird monitoring. As compared
to the aforementioned works, which focused on detecting
Fig. 1. Dataset distribution of waterbird classes. 24 classes of various bird
species at different ages and configurations. In this work, we select 15 unique
classes to be detected by the object detector, and combine the remaining
classes into the “Other” waterbird class (highlighted by italicized, blue text).
relatively large and distinct mammals, bird detection from
UAV imagery is generally regarded as a more challenging
detection task due to the unique characteristics of birds. In
particular, visual differences between bird species may be
minor, making it difficult to distinguish between them. This
difficulty is heightened for partially occluded birds, such as
birds with necks tucked under their wings, as key visual
features used to make distinctions are hidden. Borowicz et
al. [20] use DetectNet [21] to count Ad´
elie penguins in the
Danger Islands off the northern tip of the Antarctic Peninsula.
Hong et al. [22] survey various off-the-shelf CNN-based object
detectors to detect birds from UAV imagery collected of
both wild and decoy birds in various environments across
South Korea. Hayes et al. [23] use a RetinaNet to detect
seabirds, specifically Black-browed Albatrosses and Southern
Rockhopper Penguins, from UAV imagery collected of the
Falkland (Malvinas) Islands.
This work expands on the existing literature of deep
learning-based object detection for bird monitoring by sig-
nificantly increasing the number of bird species detected by
a single object detector. The aforementioned works focus on
identifying 2 or fewer bird classes that are often specific to the
surveyed islands. However, this work shows that CNN-based
object detectors are capable of detecting several bird species,
even when visually similar or imaged in challenging viewing
conditions such as dense flocks or obscuring foliage.
III. DATASET
Aerial imagery from three colonial waterbird nesting is-
lands, Chester Island, Little Bay North Island, and North Deer
摘要:

DeepobjectdetectionforwaterbirdmonitoringusingaerialimageryKrishKabra,y,z,AlexanderXiongy,z,WenbinLiy,z,MinxuanLuoz,WilliamLuz,TianjiaoYuz,JiahuiYuz,DhananjaySinghz,RaulGarciaz,MaojieTangz,HankArnoldx,AnnaValleryx,RichardGibbons{,ArkoBarmanxzRiceUniversity,Houston,TX77005,USAxHoustonAudubonSociety,...

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分类:图书资源 价格:10玖币 属性:7 页 大小:5.93MB 格式:PDF 时间:2025-05-06

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